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Sample records for flow igcc power

  1. Dynamic modeling of IGCC power plants

    International Nuclear Information System (INIS)

    Casella, F.; Colonna, P.

    2012-01-01

    Integrated Gasification Combined Cycle (IGCC) power plants are an effective option to reduce emissions and implement carbon-dioxide sequestration. The combination of a very complex fuel-processing plant and a combined cycle power station leads to challenging problems as far as dynamic operation is concerned. Dynamic performance is extremely relevant because recent developments in the electricity market push toward an ever more flexible and varying operation of power plants. A dynamic model of the entire system and models of its sub-systems are indispensable tools in order to perform computer simulations aimed at process and control design. This paper presents the development of the lumped-parameters dynamic model of an entrained-flow gasifier, with special emphasis on the modeling approach. The model is implemented into software by means of the Modelica language and validated by comparison with one set of data related to the steady operation of the gasifier of the Buggenum power station in the Netherlands. Furthermore, in order to demonstrate the potential of the proposed modeling approach and the use of simulation for control design purposes, a complete model of an exemplary IGCC power plant, including its control system, has been developed, by re-using existing models of combined cycle plant components; the results of a load dispatch ramp simulation are presented and shortly discussed. - Highlights: ► The acausal dynamic model of an entrained gasifier has been developed. ► The model can be used to perform system optimization and control studies. ► The model has been validated using field data. ► Model use is illustrated with an example showing the transient of an IGCC plant.

  2. Tampa Electric Company Polk Power Station IGCC project: Project status

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, J.E.; Carlson, M.R.; Hurd, R.; Pless, D.E.; Grant, M.D. [Tampa Electric Co., FL (United States)

    1997-12-31

    The Tampa Electric Company Polk Power Station is a nominal 250 MW (net) Integrated Gasification Combined Cycle (IGCC) power plant located to the southeast of Tampa, Florida in Polk County, Florida. This project is being partially funded under the Department of Energy`s Clean Coal Technology Program pursuant to a Round II award. The Polk Power Station uses oxygen-blown, entrained-flow IGCC technology licensed from Texaco Development Corporation to demonstrate significant reductions of SO{sub 2} and NO{sub x} emissions when compared to existing and future conventional coal-fired power plants. In addition, this project demonstrates the technical feasibility of commercial scale IGCC and Hot Gas Clean Up (HGCU) technology. The Polk Power Station achieved ``first fire`` of the gasification system on schedule in mid-July, 1996. Since that time, significant advances have occurred in the operation of the entire IGCC train. This paper addresses the operating experiences which occurred in the start-up and shakedown phase of the plant. Also, with the plant being declared in commercial operation as of September 30, 1996, the paper discusses the challenges encountered in the early phases of commercial operation. Finally, the future plans for improving the reliability and efficiency of the Unit in the first quarter of 1997 and beyond, as well as plans for future alternate fuel test burns, are detailed. The presentation features an up-to-the-minute update on actual performance parameters achieved by the Polk Power Station. These parameters include overall Unit capacity, heat rate, and availability. In addition, the current status of the start-up activities for the HGCU portion of the plant is discussed.

  3. Integrated assessment of IGCC power generation technology with carbon capture and storage (CCS)

    International Nuclear Information System (INIS)

    Cormos, Calin-Cristian

    2012-01-01

    IGCC (Integrated Gasification Combined Cycle) is a power generation technology in which the solid feedstock is partially oxidized with oxygen and steam to produce syngas. In a conventional IGCC design without carbon capture, the syngas is purified for dust and hydrogen sulphide removal and then it is sent to a CCGT (Combined Cycle Gas Turbine) for power generation. CCS (Carbon capture and storage) technologies are expected to play a significant role in the coming decades for reducing the greenhouse gas emissions. IGCC is one of the power generation technologies having the highest potential to capture CO 2 with low penalties in term of plant energy efficiency, capital and operational costs. This paper investigates the most important techno-economic and environmental indicators (e.g. power output, ancillary consumption, energy efficiency, CW consumption, normalised mass and energy balances and plant construction materials, capital and O and M (operational and maintenance) costs, specific CO 2 emissions, cost of electricity, CO 2 removal and avoidance costs etc.) for IGCC with CCS. Coal-based IGCC cases produce around 400–450 MW net electricity with 90% carbon capture rate. Similar IGCC plants without CCS were presented as references. Future IGCC developments for energy vectors poly-generation were also presented. -- Highlights: ► Techno-economical evaluations of coal-based IGCC power generation with CCS. ► Model development for capital, O and M, CO 2 capture costs and cash flow estimations. ► Technical and economic investigations of key plant design characteristics. ► Evaluations of carbon capture options for IGCC power generation technology.

  4. Green power production by co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGCC processes

    Energy Technology Data Exchange (ETDEWEB)

    Van Ree, R; Korbee, R; De Smidt, R P; Jansen, D [ECN Fuels Conversion and Environment, Petten (Netherlands); Baumann, H R; Ullrich, N [Krupp Uhde, Dortmund (Germany); Haupt, G; Zimmerman, [Siemens, Erlangen (Germany)

    1998-11-01

    The use of coal for large scale power production meets a growing environmental concern. In spite of the fact that clean coal conversion technologies integrated with high-efficiency power production facilities, such as IGCC, are developed, the aim for sustainable development strives for a power production system based on renewable energy sources. One of the most promising renewable energy sources that can be used in the Netherlands is biomass, i.e. organic waste materials and/or energy crops. To accelerate the introduction of this material, in a technical and economically acceptable way, co-gasification with fossil fuels, in particular coal, in large scale IGCC processes is considered. In this paper the technical feasibility, economic profitability, and environmental acceptability of co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGM is discussed. Both a base-case coal-fired oxygen-blown entrained-flow based IGCC process - showing strong resemblance to the Puertollano IGCC plant in Spain - and three co-gasification concepts, viz.: (1) a concept with separate dry coal and biomass feeding systems, (2) a concept with a combined dry coal/biomass-derived pyrolysis char feeding system, and (3) a concept with parallel biomass pre-treatment/gasification and combined fuel gas clean-up/power production, were defined for further consideration. The base-case system and the co-gasification concepts as well are modelled in the flowsheet simulation package ASPEN{sup +}. Steady-state integral system calculations resulted in an overall net electrical plant efficiency for the base-case system of 50. 1 %LHV (48.3 %HHV). Replacing about 10 % of the total thermal plant input (coal) by biomass (willow) resulted in a decrease of the overall net electrical plant efficiency of 1.4 to 2.1 %-points LHV, avoided specific CO2 emissions of 40-49 g/kWh{sub e}, and total avoided CO2 emissions of about 129 to 159 kt/a, all depending on the co-gasification concept

  5. Market potential of IGCC for domestic power production

    International Nuclear Information System (INIS)

    Gray, D.; Tomlinson, G.; Hawk, E.; Maskew, J.

    1999-01-01

    Mitretek Systems and CONSOL Inc. have completed the first phase of a market potential study for Integrated Coal Gasification Combined Cycle (IGCC) domestic power production. The U. S. Department of Energy (DOE) funded this study. The objective of this study is to provide DOE with data to estimate the future domestic market potential of IGCC for electricity generation. Major drivers in this study are the state of technology development, feedstock costs, environmental control costs, demand growth, and dispatchability. This study examines IGCC potential for baseload power production in the Northeast U. S., an important market area by virtue of existing coal infrastructure and proximity to coal producing regions. IGCC market potential was examined for two levels of technology development as a function of natural gas price and carbon tax. This paper discusses the results of this study, including the levels of performance and cost necessary to insure competitiveness with natural gas combined cycle plants

  6. Exergoeconomic evaluation of a KRW-based IGCC power plant

    International Nuclear Information System (INIS)

    Tsatsavonis, G.; Lin, L.; TawFik, T.; Gallaspy, D.T.

    1991-01-01

    This paper reports on a study supported by the US Department of Energy, in which several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. One of these configurations was analyzed from the exergoeconomic (thermoeconomic) viewpoint. The detailed exergoeconomic evaluation identified several changes for improving the cost effectiveness of this IGCC design configuration. Based on the cost information supplied by the M.W. Kellogg Company, an attempt was made to calculate the economically optimal exergetic efficiency for some of the most important plant components. This information is currently used in plant optimization studies

  7. RWE clean coal programme - IGCC power plant with CO{sub 2} capture & storage

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, K.-J.; Ewers, J.; Renzenbrink, W. [RWE Power AG, Essen (Germany)

    2007-07-01

    In early 2006, RWE Power announced it was building a 450 MW gross commercial IGCC power plant with carbon capture. This paper sums up the key results of the project development phase concerning the IGCC power plant and shows the basis for the feasibility phase of the project. 10 figs.

  8. Exergetic comparison of two KRW-based IGCC power plants

    International Nuclear Information System (INIS)

    Tsatsaronis, G.; Tawfik, T.; Lin, L.; Gallaspy, D.T.

    1991-01-01

    In studies supported by the U.S. Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared in this paper, from the exergetic viewpoint. The exergetic comparison identifies the causes of performance differences between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using oxygen-blown versus air-blown KRW gasifiers, and hot gas versus cold gas cleanup processes is evaluated

  9. Dynamic simulation of operating cases and malfunctions of an IGCC power plant system

    Energy Technology Data Exchange (ETDEWEB)

    Koch, I.; Hannemann, F. [Siemens AG, Power Generation (KWU), Erlangen (Germany); Hoffmann, U. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Chemische Verfahrenstechnik

    1999-07-01

    Fully integrated IGCC plants consist of several units. This novel integration of various plant systems places stiff new requirements on power plant design, as prediction of operating and faulted behavior is made more difficult by many different interactions. This is especially the case for the gas turbine fuel system in an IGCC power plant, as it affects and is affected by all of the other major plant systems. (orig.)

  10. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    International Nuclear Information System (INIS)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L.

    2009-01-01

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  11. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A. D.; Velo, E.; Nougues, J. M. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain); Puigjaner, L., E-mail: luis.puigjaner@upc.edu [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  12. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A D; Velo, E; Nougues, J M; Puigjaner, L [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  13. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  14. Techno-economic analysis of lignite fuelled IGCC with CO{sub 2} capture. Comparing fluidized bed and entrained flow gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guangjian; Wu, Zhen; Zhang, Haiying [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

    2013-07-01

    Integrated coal gasification combined cycle (IGCC) plants with pre-combustion capture of CO{sub 2} represent one of the most promising options for generating low-cost decarbonized power using bituminous coals. This work systematically quantify the effect of coal rank on the efficiency and economics of IGCC systems with CO2 capture and storage (CCS), with a special focus on comparison of systems using fluidized-bed gasifier (U-GAS) and entrained flow gasifier (Shell). It was found that the Shell IGCCs are little affect by low rank coal after pre-drying in terms of thermal efficiency and the levelized cost of electricity (LCOE) is only increase by 2-6% for lignite cases with and without CCS compared with bituminous coal cases. The specific CO{sub 2} emissions of U-GAS gasifier based lignite fuelled IGCC with CCS is 198 g/kWhe, almost two times of shell gasifier cases, mainly due to lower carbon conversion in the gasifier and the higher methane in the raw gas of gasifier. However, the total capital cost and COE of U-Gas IGCCs are 15-20% less than that of Shell IGCCs because of lower capital cost of gasifier, coal drying units and air separate units per kWe.

  15. Comprehensive report to Congress, Clean Coal Technology program: Pinon Pine IGCC Power Project

    International Nuclear Information System (INIS)

    1992-06-01

    The objective of the proposed project is to demonstrate an advanced IGCC system based upon the air-blown, fluidized-bed KRW gasifier with in-bed desulfurization using limestone sorbent and an external fixed- bed zinc ferrite sulfur removal system. Sierra Pacific Power Company (SPPC) requested financial assistance from DOE for the design, construction, and operation of a nominal 800 ton-per-day (86-Megawatt gross), air blown integrated gasification combined-cycle (IGCC) demonstration plant. The project, named the Pinon Pine IGCC Power Project, is to be located at SPPC's Tracy Station, a power generation facility located on a rural 400-acre plot about 17 miles east of Reno. The demonstration plant will produce electrical power for the utility grid. The project, including the demonstration phase, will last 96 months at a total cost of $269,993,100. DOE's share of the project cost will be 50 percent, or $134,996,550

  16. Thermodynamic assessment of IGCC power plants with hot fuel gas desulfurization

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni G.

    2010-01-01

    In IGCC power plants, hot gas desulfurization (HGD) represents an attractive solution to simplify syngas treatments and to improve the efficiency, potentially reducing the final cost of electricity. In the present study, the various consequences of the introduction of a HGD station in the power plant are discussed and evaluated, in comparison with conventional near-ambient temperature clean-up. Attention is paid to the potential improvements of the overall energy balance of the complete power station, along with the requirements of the sorbent regeneration process, to the influence of the desulfurization temperature and to the different solutions needed to control the NO x emissions (altered by the presence of HGD). The net performance of complete IGCC power plants (with HGD or with conventional desulfurization) were predicted, with reference to status-of-the-art solutions based on an entrained flow, dry-feed, oxygen-blown gasifier and on an advanced, FB-class combined cycle. The net efficiency experiences about 2.5% point improvement with HGD, even if a small reduction in the power output was predicted, when using the same combustion turbine. An exhaustive sensitivity analysis was carried out to evaluate the effects of different working conditions at the HGD station, e.g. desulfurization temperature and oxygen content in the gaseous stream for sorbent regeneration. According to the obtained results, these parameters have a weak influence on the efficiency. In particular, a very elevated desulfurization temperature (above 400-500 o C) does not provide decisive thermodynamic advantages. Therefore, the HGD unit optimization can be driven by technical and economical aspects and by emission abatement requirements. For instance, utilization of nitrogen for HGD sorbent regeneration (rather than for syngas dilution) and higher fuel temperature may improve the NO formation. Hence, different strategies to achieve acceptable NO x emissions (e.g. steam dilution) and their

  17. A comparison of improved power plant technologies on lignite with (PFBC) and (IGCC) cycles

    International Nuclear Information System (INIS)

    Cherepnalkovski, Ilija

    1997-01-01

    Technologies and process diagrams descriptions for PFBC (Pressurised Fluidized Bed Combustion) and IGCC (Integrated Gasification Combined Cycle) are presented as for improved cycles with modern clean coal technologies, the most popular currently. A special attention is paid to the possibilities for Macedonian lignites use on the power plants with PFBC and IGCC cycles. The comparison of the above mention technologies has been done particularly on the desulfurization, NO x reduction, ash elimination and its use in the building and construction industries. A comparison between the power plants with PFBC and IGCC cycles is made by the following criteria: cycle efficiency, desulfurization and nitrogen oxides reduction, power plant complexity and their cost, as well as plant reliability. (Author)

  18. Recovery of flue gas energy in heat integrated IGCC power plants using the contact economizer system

    CSIR Research Space (South Africa)

    Madzivhandila, V

    2010-10-01

    Full Text Available Asia Pacific Confederation of APCChE 2010 Chemical Engineering Congress October 5-8, 2010, Taipei � �� Recovery of flue gas energy in heat integrated IGCC power plants using the contact economizer system Vhutshilo Madzivhandilaa, Thokozani... temperature and the thermal efficiency of the plant. The 13th Asia Pacific Confederation of APCChE 2010 Chemical Engineering Congress October 5-8, 2010, Taipei � �� 1. Introduction The IGCC (Integrated Gasification Combined Cycle) is one...

  19. Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

    2010-07-01

    Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

  20. Development of advanced air-blown entrained-flow two-stage bituminous coal IGCC gasifier

    Directory of Open Access Journals (Sweden)

    Abaimov Nikolay A.

    2017-01-01

    Full Text Available Integrated gasification combined cycle (IGCC technology has two main advantages: high efficiency, and low levels of harmful emissions. Key element of IGCC is gasifier, which converts solid fuel into a combustible synthesis gas. One of the most promising gasifiers is air-blown entrained-flow two-stage bituminous coal gasifier developed by Mitsubishi Heavy Industries (MHI. The most obvious way to develop advanced gasifier is improvement of commercial-scale 1700 t/d MHI gasifier using the computational fluid dynamics (CFD method. Modernization of commercial-scale 1700 t/d MHI gasifier is made by changing the regime parameters in order to improve its cold gas efficiency (CGE and environmental performance, namely H2/CO ratio. The first change is supply of high temperature (900°C steam in gasifier second stage. And the second change is additional heating of blast air to 900°C.

  1. Computer models and simulations of IGCC power plants with Canadian coals

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Furimsky, E.

    1999-07-01

    In this paper, three steady state computer models for simulation of IGCC power plants with Shell, Texaco and BGL (British Gas Lurgi) gasifiers will be presented. All models were based on a study by Bechtel for Nova Scotia Power Corporation. They were built by using Advanced System for Process Engineering (ASPEN) steady state simulation software together with Fortran programs developed in house. Each model was integrated from several sections which can be simulated independently, such as coal preparation, gasification, gas cooling, acid gas removing, sulfur recovery, gas turbine, heat recovery steam generation, and steam cycle. A general description of each process, model's overall structure, capability, testing results, and background reference will be given. The performance of some Canadian coals on these models will be discussed as well. The authors also built a computer model of IGCC power plant with Kellogg-Rust-Westinghouse gasifier, however, due to limitation of paper length, it is not presented here.

  2. Dynamic simulation of a low-temperature rectification Column as part of an IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Hanke, R. [Leipzig University of Applied Sciences, Department of Mechanical and Energy Engineering, P.O. Box 300066, D-04251 Leipzig (Germany); Hannemann, F. [Siemens AG - Power Generation, PG CTET, P.O. Box 3220, D-91050 Erlangen (Germany); Sundmacher, K. [Max Planck Institute of Dynamics of Complex Technical Systems, Sandtorstrasse 1, D-39106 Magdeburg (Germany); Otto-von-Guericke University Magdeburg, Faculty of Process and Systems Engineering, P.O. Box 4120, D-39106 Magdeburg (Germany)

    2003-11-01

    IGCC plants offer the opportunity to utilize fossil energy sources, like coal or heavy refinery residues, to satisfy increasing energy demand while considering strict environmental constraints. Such a plant consists of a combined power cycle, a fuel gasifier with downstream fuel gas conditioning and an air separation unit (ASU), where the oxygen required for gasification is produced. The low-temperature rectification column as the core of the ASU strongly affects the transient behavior of the system. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  3. Thermodynamic simulation of CO{sub 2} capture for an IGCC power plant using the calcium looping cycle

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y. [National Engineering Laboratory for Coal-Burning Pollutant Emission Reduction, Shandong University, Jinan (China); Zhao, C.; Ren, Q. [School of Energy and Environment, Southeast University, Nanjing (China)

    2011-06-15

    A CO{sub 2} capture process for an integrated gasification combined cycle (IGCC) power plant using the calcium looping cycle was proposed. The CO{sub 2} capture process using natural and modified limestone was simulated and investigated with the software package Aspen Plus. It incorporated a fresh feed of sorbent to compensate for the decay in CO{sub 2} capture activity during long-term cycles. The sorbent flow ratios have significant effect on the CO{sub 2} capture efficiency and net efficiency of the CO{sub 2} capture system. The IGCC power plant, using the modified limestone, exhibits higher CO{sub 2} capture efficiency than that using the natural limestone at the same sorbent flow ratios. The system net efficiency using the natural and modified limestones achieves 41.7% and 43.1%, respectively, at the CO{sub 2} capture efficiency of 90% without the effect of sulfation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K; Keraenen, H [Enviropower Inc., Espoo (Finland)

    1997-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  5. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  6. The reliability of integrated gasification combined cycle (IGCC) power generation units

    Energy Technology Data Exchange (ETDEWEB)

    Higman, C.; DellaVilla, S.; Steele, B. [Syngas Consultants Ltd. (United Kingdom)

    2006-07-01

    This paper presents two interlinked projects aimed at supporting the improvement of integrated gasification combined cycle (IGCC) reliability. The one project comprises the extension of SPS's existing ORAP (Operational Reliability Analysis Program) reliability, availability and maintainability (RAM) tracking technology from its existing base in natural gas open and combined cycle operations into IGCC. The other project is using the extended ORAP database to evaluate performance data from existing plants. The initial work has concentrated on evaluating public domain data on the performance of gasification based power and chemical plants. This is being followed up by plant interviews in some 20 plants to verify and expand the database on current performance. 23 refs., 8 figs., 2 tabs.

  7. Thermal expansion of slag and fly ash from coal gasification in IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    M. Aineto; A. Acosta; J.M.A. Rincon; M. Romero [University of Castilla La Mancha, Ciudad Real (Spain). Laboratory of Applied Mineralogy

    2006-11-15

    Integrated gasification in combined cycle (IGCC) is an electrical power generation system which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and pressure in reducing atmosphere. Under that conditions, gases such as H{sub 2}, N{sub 2} or CO, which are the main components of the gas mixture in the gasifier, show a high solubility in the melt and during the cooling remain enclosed in the vitreous slag. When these wastes are afterward thermal treated in oxidizing conditions, two phenomena occur. The development of a crystalline phase by devitrification of the glassy matrix and the releasing of the enclosed gas, which starts at temperatures nearly to the softening point. At higher temperatures the bubbles with increasing kinetic energy tend to ascend with difficulty through the viscous liquid phase and promotes an expansive reaction, giving rise to a foam glass-ceramic product. This paper has been focused on the study of thermal expansion in slag and fly ash samples from the ELCOGAS IGCC power plant located in Puertollano (Spain). 18 refs., 11 figs., 1 tab.

  8. The role of IGCC technology in power generation using low-rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Juangjandee, Pipat

    2010-09-15

    Based on basic test results on the gasification rate of Mae Moh lignite coal. It was found that an IDGCC power plant is the most suitable for Mae Moh lignite. In conclusion, the future of an IDGCC power plant using low-rank coal in Mae Moh mine would hinge on the strictness of future air pollution control regulations including green-house gas emission and the constraint of Thailand's foreign currency reserves needed to import fuels, in addition to economic consideration. If and when it is necessary to overcome these obstacles, IGCC is one variable alternative power generation must consider.

  9. Efficiency enhancement in IGCC power plants with air-blown gasification and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni

    2013-01-01

    Air-blown IGCC systems with hot fuel gas clean-up are investigated. In detail, the gas clean-up station consists of two reactors: in the first, the raw syngas exiting the gasifier and passed through high-temperature syngas coolers is desulfurized by means of a zinc oxide-based sorbent, whereas in the second the sulfided sorbent is duly regenerated. The hot fuel gas clean-up station releases H 2 S-free syngas, which is ready to fuel the combustion turbine after hot gas filtration, and a SO 2 -laden stream, which is successively treated in a wet scrubber. A thermodynamic analysis of two air-blown IGCC systems, the first with cold fuel gas clean-up and the second with hot fuel gas clean-up, both with a state-of-the-art combustion turbine as topping cycle, shows that it is possible to obtain a really attractive net efficiency (more than 51%) for the second system, with significant improvements in comparison with the first system. Nevertheless, higher efficiency is accomplished with a small reduction in the power output and no sensible efficiency improvements seem to be appreciated when the desulfurization temperature increases. Other IGCC systems, with an advanced 1500 °C-class combustion turbine as the result of technology improvements, are investigated as well, with efficiency as high as 53%. - Highlights: ► Hot fuel gas clean-up is a highly favorable technology for IGCC concepts. ► Significant IGCC efficiency improvements are possible with hot fuel gas clean-up. ► Size reductions of several IGCC components are possible. ► Higher desulfurization temperatures do not sensibly affect IGCC efficiency. ► IGCC efficiency as high as 53% is possible with a 1500°C-class combustion turbine

  10. Puertollano IGCC Power Plant; Central de Gasificacion Integrada en Ciclo Combinado de Puertollano

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The Puertollano IGCC Power Plant, rated 335 MW and located in Puertollano, Ciudad Real, in the central area of Spain, is a project led by ELCOGAS, a company incorporated by the European utilities ENDESA, ELECTRICITE DE FRANCE, IBERDROLA HIDROCANTABRICO ELECTRICIDADE DE PURTUGAL, ENEL and NATIONAL POWER and the technology and equipment suppliers SIEMENS, KRUPP UHDE and BABCOCK WILCOX ESPANOLA. IGCC technology is based in a process of coal gasification to obtain a clean combustion synthetic gas, integrated with a combined cycle, agas and steam, electricity-generating unit. The energy efficiency which is aimed to achieve at the Plant is 46% in ISO conditions. The Gasification unit uses the process of pressurised entrained flow for coal gasification. The gas is produced by the reaction of coal with oxygen at high temperatures, of up to 1600 degree centigree. This process is capable of gasifying a wide variety of types and qualities of coal for the production of a synthetic fuel gas. In the case of Puertollano, the raw fuel is a 50% mixture by weight of local coal and petroleum coke. The oxygen needed in the process and the nitrogen used for covering the fuel is generated in the Air Separation. The Gas Cleaning and Sulphur Recovery Unit clean the gases from contaminants and solid particles before to send them to the Gas Turbine. The clean gas is burnt in gas turbine of the Combined Cycle Plant, producing electricity. The exhaust gases feed a heat recovery steam generator, which produces steam used to generate additional electricity in a conventional steam turbine. The gas turbine is capable of operating both with synthetic gas and with natural gas, allowing operation flexibility. The net output of the plant up to December 1999 was 3.061 GWh, from them 344 GWh were produced with synthetic gas. This project has an important technological value, being the first power plant which uses coal gasification to feed a combined cycle in Spain and being also the biggest power plant

  11. Multi-fuel multi-product operation of IGCC power plants with carbon capture and storage (CCS)

    International Nuclear Information System (INIS)

    Cormos, Ana-Maria; Dinca, Cristian; Cormos, Calin-Cristian

    2015-01-01

    This paper investigates multi-fuel multi-product operation of IGCC plants with carbon capture and storage (CCS). The investigated plant designs co-process coal with different sorts of biomass (e.g. sawdust) and solid wastes, through gasification, leading to different decarbonised energy vectors (power, hydrogen, heat, substitute natural gas etc.) simultaneous with carbon capture. Co-gasification of coal with different renewable energy sources coupled with carbon capture will pave the way towards zero emissions power plants. The energy conversions investigated in the paper were simulated using commercial process flow modelling package (ChemCAD) in order to produce mass and energy balances necessary for the proposed evaluation. As illustrative cases, hydrogen and power co-generation and Fischer–Tropsch fuel synthesis (both with carbon capture), were presented. The case studies investigated in the paper produce a flexible ratio between power and hydrogen (in the range of 400–600 MW net electricity and 0–200 MW th hydrogen considering the lower heating value) with at least 90% carbon capture rate. Special emphasis were given to fuel selection criteria for optimisation of gasification performances (fuel blending), to the selection criteria for gasification reactor in a multi-fuel multi-product operation scenario, modelling and simulation of whole process, to thermal and power integration of processes, flexibility analysis of the energy conversion processes, in-depth techno-economic and environmental assessment etc. - Highlights: • Assessment of IGCC-based energy vectors poly-generation systems with CCS. • Optimisation of gasification performances and CO 2 emissions by fuel blending. • Multi-fuel multi-product operation of gasification plants

  12. Towards retrofitting integrated gasification combined cycle (IGCC) power plants with solid oxide fuel cells (SOFC) and CO

    NARCIS (Netherlands)

    Thallam Thattai, A.; Oldenbroek, V.D.W.M.; Schoenmakers, L; Woudstra, T.; Purushothaman Vellayani, A.

    2017-01-01

    This article presents a detailed thermodynamic case study based on the Willem-Alexander Centrale (WAC) power plant in the Netherlands towards retrofitting SOFCs in existing IGCC power plants with a focus on near future implementation. Two systems with high percentage (up to 70%) biomass

  13. The installation IGCC power plans in the petroleum refinement: international experiences and lessons for Mexico; La instalacion de plantas IGCC en la refinacion de petroleo: experiencias internacionales y lecciones para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Joel [Ecole du Petrole et des Moteurs, Institut Franzais du Petrole, (France)

    2004-06-15

    In this work, are presented the technical and economic elements of the international experience for the installation of IGCC power plants in the petroleum refinement and the lessons for Mexico in the installation of this technology in PEMEX Refinacion are analyzed. The construction of IGCC power plants in the petroleum refinement has grown 14.3 % at worldwide level as of 1996, in which there was already an installed capacity of 160 MW. At the end of 2003 an installed capacity of 2,500 MW was reached. The growth in the installation of IGCC power plants fundamentally appears in Europe, being Italy and Spain leader countries in the construction of this technology in the petroleum refinement. However, countries like Holland, Japan, Singapore and the United States count on IGCC power plants for electricity and hydrogen generation, which take advantage of low value fuels such as vacuum tower residues, petroleum coke, asphalt, liquid fuels, among others. In Mexico, the installation IGCC power plants in the petroleum refinement is null, nevertheless Petroleos Mexicanos counts with the approval of the government for the installation of cogeneration power plants in its facilities. This approval would allow PEMEX to carry out projects for the installation IGCC power plants, specifically in PEMEX Refinacion, for the generation of electricity and hydrogen from the advantage of heavy residues of low economic value. The opportunity that the installation IGCC power plants in the petroleum refinement offers is directed towards the commercialization of the electricity and hydrogen, which would impel PEMEX Refinacion to enter the competition of the electrical market in Mexico. [Spanish] En este trabajo, se presentan los elementos tecnicos y economicos de la experiencia internacional para la instalacion de plantas IGCC en la refinacion de petroleo y se analizan las lecciones para Mexico en la instalacion de esta tecnologia en PEMEX Refinacion. La construccion de plantas IGCC en la

  14. Integration optimisation of elevated pressure air separation unit with gas turbine in an IGCC power plant

    International Nuclear Information System (INIS)

    Han, Long; Deng, Guangyi; Li, Zheng; Wang, Qinhui; Ileleji, Klein E.

    2017-01-01

    Highlights: • IGCC thermodynamic model was setup carefully. • Simulations focus on integration between an elevated pressure ASU with gas turbine. • Different recommended solutions from those of low pressure ASUs are figured out. • Full N 2 injection and 80% air extraction was suggested as the optimum integration. - Abstract: The integration optimisation between an elevated pressure air separation unit (EP-ASU) and gas turbine is beneficial to promote net efficiency of an integrated gasification combined cycle (IGCC) power plant. This study sets up the thermodynamic model for a 400 MW plant specially coupled with an EP-ASU, aiming to examine system performances under different integrations and acquire the optimum solution. Influences of air extraction rate at conditions of without, partial and full N 2 injection, as well as the effects of N 2 injection rate when adopting separate ASU, partial and full integrated ASU were both analysed. Special attention has been paid to performance differences between utilising an EP-ASU and a low pressure unit. Results indicated that integration solution with a separate EP-ASU or without N 2 injection would not be reasonable. Among various recommended solutions for different integration conditions, N 2 injection rate increased with the growth of air extraction rate. The integration with an air extraction rate of 80% and full N 2 injection was suggested as the optimum solution. It is concluded that the optimum integration solution when adopting an EP-ASU is different from that using a low pressure one.

  15. Pushing forward IGCC and CO{sub 2}-free power plant technology at Siemens

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, E.; Vortmeyer, N.; Zimmermann, G. [Siemens AG, Erlangen (Germany). Power Generation

    2004-07-01

    Siemens Power Generation has entered into several R & D projects within the European Commissions' 5th and 6th Framework Programs. One objective of those projects is to develop advanced modular IGCC concepts for in-refinery energy and hydrogen supply. Additional projects are dealing with pre- and post-combustion decarbonisation technologies, which should achieve high carbon dioxide capture at low costs. In parallel, the development of advanced combustion systems including enhanced fuel flexibility and application of low BTU gases in the highly efficient Siemens V94.3A gas turbine are in progress. In further step the technology for burning hydrogen enriched gases resulting from decarbonisation in CO{sub 2} free power plants will be provided. This report documents the current status of these activities. 9 refs., 12 figs.

  16. Incorporating IGCC and CaO sorption-enhanced process for power generation with CO2 capture

    International Nuclear Information System (INIS)

    Chen, Shiyi; Xiang, Wenguo; Wang, Dong; Xue, Zhipeng

    2012-01-01

    Highlights: ► CaO sorption-enhanced process is incorporated with IGCC for CO 2 capture. ► IGCC–CCS is simplified using CaO sorption-enhanced process. ► The electricity efficiency is around 31–33% and CO 2 capture efficiency exceeds 95%. ► Parameters such as sorption pressure influence the system performance. -- Abstract: Integrated gasification combined cycle (IGCC) is a power generation technology to convert solid fuels into electricity. IGCC with CCS is regarded as a promising option to mitigate CO 2 emission. In this paper, the CaO sorption-enhanced process is incorporated downstream with coal gasification to produce a hydrogen-rich stream for electricity production and CO 2 separation. A WGS-absorber substitutes the high- and low-temperature water–gas shift reactors and desulfurization units in conventional IGCC–CCS to produce a hydrogen-rich stream, which is sent onto a gas turbine. CaO is used as the sorbent to enhance hydrogen production and for CO 2 capture. Regeneration of CaO is completed via calcination in a regenerator vessel. The IGCC with CaO sorption-enhanced process is modeled and simulated using Aspen Plus software. Two commercial available gasification technologies, Shell and Texaco, are integrated with the sorption-enhanced process. The results showed IGCC with CaO sorption-enhanced process has a satisfactory system performance. Even though the net electricity efficiency is not as high as expected, just around 30–33%, the system has a high CO 2 capture efficiency ∼97% and low pollutant emissions. Moreover, compared with conventional IGCC–CCS, the schematic diagram of the IGCC–CCS process is simplified. Parameters that affect the plant performance are analyzed in the sensitive analysis, including WGS-absorber temperature, H 2 O/CO ratio, pressure, etc. Some challenges to the system are also discussed.

  17. Proceedings of the coal-fired power systems 94: Advances in IGCC and PFBC review meeting. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, H.M.; Staubly, R.K.; Venkataraman, V.K. [eds.

    1994-06-01

    The Coal-Fired Power Systems 94 -- Advances in IGCC and PFBC Review Meeting was held June 21--23, 1994, at the Morgantown Energy Center (METC) in Morgantown, West Virginia. This Meeting was sponsored and hosted by METC, the Office of Fossil Energy, and the US Department of Energy (DOE). METC annually sponsors this conference for energy executives, engineers, scientists, and other interested parties to review the results of research and development projects; to discuss the status of advanced coal-fired power systems and future plans with the industrial contractors; and to discuss cooperative industrial-government research opportunities with METC`s in-house engineers and scientists. Presentations included industrial contractor and METC in-house technology developments related to the production of power via coal-fired Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) systems, the summary status of clean coal technologies, and developments and advancements in advanced technology subsystems, such as hot gas cleanup. A keynote speaker and other representatives from the electric power industry also gave their assessment of advanced power systems. This meeting contained 11 formal sessions and one poster session, and included 52 presentations and 24 poster presentations. Volume I contains papers presented at the following sessions: opening commentaries; changes in the market and technology drivers; advanced IGCC systems; advanced PFBC systems; advanced filter systems; desulfurization system; turbine systems; and poster session. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  18. CO{sub 2}-capture in coal based IGCC power plants

    Energy Technology Data Exchange (ETDEWEB)

    Van Aart, F.; Fleuren, W.; Kamphuis, H.; Ploumen, P.; Jelles, S. [KEMA, Arnhem (Netherlands)

    2007-07-01

    The paper discusses IGCC with carbon capture and storage (CCS), both for retrofit and capture ready plants. The penalties for carbon dioxide capture are given, along with its effect on CAPEX and OPEC costs. 3 refs., 9 figs.

  19. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    Energy Technology Data Exchange (ETDEWEB)

    Koljonen, T.; Solantausta, Y. [VTT Energy, Espoo (Finland). New Energy Technologies; Salo, K.; Horvath, A. [Carbona Inc. (Finland)

    1999-11-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  20. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    International Nuclear Information System (INIS)

    Koljonen, T.; Solantausta, Y.

    1999-01-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  1. Design and evaluation of an IGCC power plant using iron-based syngas chemical-looping (SCL) combustion

    International Nuclear Information System (INIS)

    Sorgenfrei, Max; Tsatsaronis, George

    2014-01-01

    Highlights: • A new concept for power generation including carbon capture was found. • The air reactor temperature significantly influences the net efficiency. • The use of a CO 2 turbine decreases the net efficiency. • Compared to a conventional IGCC with 90% CO 2 capture the net efficiency increases. - Abstract: Chemical-looping combustion (CLC) is a novel and promising combustion technology with inherent separation of the greenhouse gas CO 2 . This paper focuses on the design and thermodynamic evaluation of an integrated gasification combined-cycle (IGCC) process using syngas chemical looping (SCL) combustion for generating electricity. The syngas is provided by coal gasification; the gas from the gasifier is cleaned using high-temperature gas desulfurization (HGD). In this study, the oxygen carrier iron oxide (Fe 2 O 3 ) is selected to oxidize the syngas in a multistage moving-bed reactor. The resulting reduced iron particles then consist of FeO and Fe 3 O 4 . To create a closed-cycle operation, these particles are partially re-oxidized with steam in a fluidized-bed regenerator to pure Fe 3 O 4 and then fully re-oxidized in a fluidized-bed air combustor to Fe 2 O 3 . One advantage of this process is the co-production of hydrogen diluted with water vapor within the steam regenerator. Both the HGD and CLC systems are not under commercial operation so far. This mixture is fed to a gas turbine for the purpose of generating electricity. The gas turbine is expected to exhibit low NO x emissions due to the high ratio of water in the combustion chamber. Cooling the flue gas in the HRSG condenses the water vapor to yield high-purity CO 2 for subsequent compression and disposal. To evaluate the net efficiency, two conventional syngas gasifiers are considered, namely the BGL slagging gasifier and the Shell entrained-flow gasifier. The option of using a CO 2 turbine after the SCL-fuel reactor is also investigated. A sensitivity analysis is performed on the SCL

  2. Development of ITM oxygen technology for integration in IGCC and other advanced power generation

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Phillip A. [Air Products And Chemicals, Inc., Allentown, PA (United States)

    2015-03-31

    Ion Transport Membrane (ITM) technology is based on the oxygen-ion-conducting properties of certain mixed-metal oxide ceramic materials that can separate oxygen from an oxygen-containing gas, such as air, under a suitable driving force. The “ITM Oxygen” air separation system that results from the use of such ceramic membranes produces a hot, pure oxygen stream and a hot, pressurized, oxygen-depleted stream from which significant amounts of energy can be extracted. Accordingly, the technology integrates well with other high-temperature processes, including power generation. Air Products and Chemicals, Inc., the Recipient, in conjunction with a dozen subcontractors, developed ITM Oxygen technology under this five-phase Cooperative Agreement from the laboratory bench scale to implementation in a pilot plant capable of producing power and 100 tons per day (TPD) of purified oxygen. A commercial-scale membrane module manufacturing facility (the “CerFab”), sized to support a conceptual 2000 TPD ITM Oxygen Development Facility (ODF), was also established and operated under this Agreement. In the course of this work, the team developed prototype ceramic production processes and a robust planar ceramic membrane architecture based on a novel ceramic compound capable of high oxygen fluxes. The concept and feasibility of the technology was thoroughly established through laboratory pilot-scale operations testing commercial-scale membrane modules run under industrial operating conditions with compelling lifetime and reliability performance that supported further scale-up. Auxiliary systems, including contaminant mitigation, process controls, heat exchange, turbo-machinery, combustion, and membrane pressure vessels were extensively investigated and developed. The Recipient and subcontractors developed efficient process cycles that co-produce oxygen and power based on compact, low-cost ITMs. Process economics assessments show significant benefits relative to state

  3. Modelling and dynamics of an air separation rectification column as part of an IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, B.; Hanke-Rauschenbach, R.; Hannemann, F.; Sundmacher, K. [Otto Von Guericke University, Magdeburg (Germany)

    2006-04-15

    An Integrated Gasification Combined Cycle plant (IGCC) opens the well-proven and highly efficient combined cycle process to fossil fuels, like coal or heavy refinery residues. Such a plant thereby possesses a novel linkage of typical energy engineering related units, e.g. a gas turbine and typical process engineering parts, which in the present case is an air separation plant. Different responses from the connected components can cause undesired mass flow fluctuations within the system especially during changing load demands. The cryogenic rectification column, as the core of the air separation plant, strongly affects the system's transient behaviour. The upper part of such a heat-integrated double column, a packed column with structured packing, has therefore been more closely investigated in the present paper. For this purpose, a dynamic model of such a column has been developed which is also able to describe the pressure dynamics supposedly responsible for these mass flow fluctuations. The transient behaviour of the uncontrolled column is analysed and discussed with special regard to pressure dynamics. The column pressure responds to disturbances on two different time scales. The short-term response, which is in the range of 100-200 s, is governed by the transient behaviour of the fluid dynamics and is discussed in detail. The long-term response is dominated by the nonlinear dynamics of the concentration profiles. The time constant of this response depends strongly on the direction and intensity of the disturbance and takes from 10,000 up to several 100,000 s.

  4. Economic evaluation of pre-combustion CO2-capture in IGCC power plants by porous ceramic membranes

    International Nuclear Information System (INIS)

    Franz, Johannes; Maas, Pascal; Scherer, Viktor

    2014-01-01

    Highlights: • Process simulations of IGCC with pre-combustion capture via membranes were done. • Most promising technology is the water–gas-shift-membrane-reactor (WGSMR). • Energetic evaluations showed minimum efficiency loss of 5.8%-points for WGSMR. • Economic evaluations identified boundary limits of membrane technology. • Cost of electricity for optimum WGSMR-case is 57 €/MW h under made assumptions. - Abstract: Pre-combustion-carbon-capture is one of the three main routes for the mitigation of CO 2 -emissions by fossil fueled power plants. Based on the data of a detailed technical evaluation of CO 2 -capture by porous ceramic membranes (CM) and ceramic membrane reactors (WGSMR) in an Integrated-Gasification-Combined-Cycle (IGCC) power plant this paper focuses on the economic effects of CO 2 -abatement. First the results of the process simulations are presented briefly. The analysis is based on a comparison with a reference IGCC without CO 2 -capture (dry syngas cooling, bituminous coal, efficiency of 47.4%). In addition, as a second reference, an IGCC process with CO 2 removal based on standard Selexol-scrubbing is taken into account. The most promising technology for CO 2 -capture by membranes in IGCC applications is the combination of a water gas shift reactor and a H 2 -selective membrane into one water gas shift membrane reactor. For the WGSRM-case efficiency losses can be limited to about 6%-points (including losses for CO 2 compression) for a CO 2 separation degree of 90%. This is a severe reduction of the efficiency loss compared to Selexol (10.3% points) or IGCC–CM (8.6% points). The economic evaluation is based on a detailed analysis of investment and operational costs. Parameters like membrane costs and lifetime, costs of CO 2 -certificates and annual operating hours are taken into account. The purpose of these evaluations is to identify the minimum cost of electricity for the different capture cases for the variation of the boundary

  5. Advanced IGCC/Hydrogen Gas Turbine Development

    Energy Technology Data Exchange (ETDEWEB)

    York, William [General Electric Company, Schenectady, NY (United States); Hughes, Michael [General Electric Company, Schenectady, NY (United States); Berry, Jonathan [General Electric Company, Schenectady, NY (United States); Russell, Tamara [General Electric Company, Schenectady, NY (United States); Lau, Y. C. [General Electric Company, Schenectady, NY (United States); Liu, Shan [General Electric Company, Schenectady, NY (United States); Arnett, Michael [General Electric Company, Schenectady, NY (United States); Peck, Arthur [General Electric Company, Schenectady, NY (United States); Tralshawala, Nilesh [General Electric Company, Schenectady, NY (United States); Weber, Joseph [General Electric Company, Schenectady, NY (United States); Benjamin, Marc [General Electric Company, Schenectady, NY (United States); Iduate, Michelle [General Electric Company, Schenectady, NY (United States); Kittleson, Jacob [General Electric Company, Schenectady, NY (United States); Garcia-Crespo, Andres [General Electric Company, Schenectady, NY (United States); Delvaux, John [General Electric Company, Schenectady, NY (United States); Casanova, Fernando [General Electric Company, Schenectady, NY (United States); Lacy, Ben [General Electric Company, Schenectady, NY (United States); Brzek, Brian [General Electric Company, Schenectady, NY (United States); Wolfe, Chris [General Electric Company, Schenectady, NY (United States); Palafox, Pepe [General Electric Company, Schenectady, NY (United States); Ding, Ben [General Electric Company, Schenectady, NY (United States); Badding, Bruce [General Electric Company, Schenectady, NY (United States); McDuffie, Dwayne [General Electric Company, Schenectady, NY (United States); Zemsky, Christine [General Electric Company, Schenectady, NY (United States)

    2015-07-30

    The objective of this program was to develop the technologies required for a fuel flexible (coal derived hydrogen or syngas) gas turbine for IGCC that met DOE turbine performance goals. The overall DOE Advanced Power System goal was to conduct the research and development (R&D) necessary to produce coal-based IGCC power systems with high efficiency, near-zero emissions, and competitive capital cost. To meet this goal, the DOE Fossil Energy Turbine Program had as an interim objective of 2 to 3 percentage points improvement in combined cycle (CC) efficiency. The final goal is 3 to 5 percentage points improvement in CC efficiency above the state of the art for CC turbines in IGCC applications at the time the program started. The efficiency goals were for NOx emissions of less than 2 ppm NOx (@15 % O2). As a result of the technologies developed under this program, the DOE goals were exceeded with a projected 8 point efficiency improvement. In addition, a new combustion technology was conceived of and developed to overcome the challenges of burning hydrogen and achieving the DOE’s NOx goal. This report also covers the developments under the ARRA-funded portion of the program that include gas turbine technology advancements for improvement in the efficiency, emissions, and cost performance of gas turbines for industrial applications with carbon capture and sequestration. Example applications could be cement plants, chemical plants, refineries, steel and aluminum plants, manufacturing facilities, etc. The DOE’s goal for more than 5 percentage point improvement in efficiency was met with cycle analyses performed for representative IGCC Steel Mill and IGCC Refinery applications. Technologies were developed in this program under the following areas: combustion, larger latter stage buckets, CMC and EBC, advanced materials and coatings, advanced configurations to reduce cooling, sealing and rotor purge flows, turbine aerodynamics, advanced sensors, advancements in first

  6. Feasibility analysis of gas turbine inlet air cooling by means of liquid nitrogen evaporation for IGCC power augmentation

    International Nuclear Information System (INIS)

    Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Vaccari, Anna; Venturini, Mauro

    2015-01-01

    Integrated Gasification Combined Cycles (IGCC) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, an Air Separation Unit (ASU) is also part of the plant. In this paper, a system for power augmentation in IGCC is evaluated. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first liquefied to be used for inlet air cooling or stored for later use. This system is not characterized by the limits of water evaporative cooling systems (the lower temperature is limited by air saturation) and refrigeration cooling (the effectiveness is limited by the pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for energy conversion system simulation. A sensitivity analysis on the main parameters is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year and by comparing to traditional inlet air cooling strategies. - Highlights: • Gas turbine inlet air cooling by means of liquid nitrogen spray. • Humidity condensation may form a fog which provides further power augmentation. • High peak and off peak electric energy price ratios make the system profitable

  7. Analysis of IGCC-based plants with carbon capture for an efficient and flexible electric power generation

    International Nuclear Information System (INIS)

    Sorgenfrei, Max

    2016-01-01

    In this work, systems based on the Integrated gasification combined cycle (IGCC) technology with carbon capture are analyzed regarding an efficient and flexible electric power generation. All analysis are related to a high-efficiency or low-cost IGCC base case with carbon capture which are both commercially available. In the high-efficiency base case, thermodynamic inefficiencies are determined based on a conventional exergy analysis. The gasifier followed by the combustion chamber of the gas turbine running on syngas are rated to the largest inefficiencies. Based on an advanced exergy analysis, the inefficiencies are split into an avoidable and unavoidable part as well as an endogenous and exogenous part. For example, it was found that about half of the inefficiencies within the gasifier are caused by other components of the overall system(exogenous part). Further investigations on the combination of both splitting types are presented. The gas turbine system is identified to be a major component and therefore a detailed model was developed using state-of-the-art technologies. Based on this model, 12 types of characteristic inefficiencies were determined and rated by their exergy destruction. Chemical-Looping Combustion (CLC) is one of the most promising technologies to enhance the available IGCC design. CLC uses composite metal particles acting as an oxygen carrier to transport oxygen from the air to the fuel gas through a redox-cycle. Thus, the inefficiencies associated with the combustion process decrease and the application of physical absorption for capturing CO 2 is replaced by an inherent CO 2 -capture. In this work, the most suitable oxygen carriers for CLC using syngas (nickel oxide and iron oxide) are analyzed at different temperatures. Moreover, different types of gasifier as well as CLC reactor designs are analyzed. Regenerating the oxygen carrier by steam and air, produces additional hydrogen from the reduction of steam which is further combusted

  8. IGCC crosses the threshold

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, J E

    1986-07-01

    This paper describes the development of the Texaco Coal Gasification Process (TCGP), the first of the advanced gasification processes to become commercialized. The utilization of this process in various demonstration and commercial plants is described. The design of the Cool Water integrated gasification combined cycle (IGCC) plant in California is discussed in some detail. This plant has been operating successfully since June 1984, and has demonstrated that the Texaco gasification technology for electric power generation is commercially viable, can use many different feedstocks, has substantial efficiency growth potential, can provide competitively lower cost electric power, and offers vastly superior environmental performance.

  9. Recovery of flue gas energy in heat-integrated gasification combined cycle (IGCC) power plants using the contact economizer system

    CSIR Research Space (South Africa)

    Madzivhandila, VA

    2011-03-01

    Full Text Available (flue gas) stream of a heat-integrated gasification combined cycle (IGCC) design of the Elcogas plant adopted from previous studies. The underlying support for this idea was the direct relationship between efficiency of the IGCC and the boiler feedwater...

  10. Air permitting of IGCC plants

    Energy Technology Data Exchange (ETDEWEB)

    Chitikela, S.R.

    2007-07-01

    The IGCC process is, currently, the preferred choice over conventional thermal power production in regard to cleanup of fuel and significantly reduced contaminant emissions. The air permitting requirements include the review of: feed preparation and PM emissions; feed gasification and contaminant emissions; elemental sulfur recovery and SO{sub 2} emissions; options for carbon-dioxide recovery; syngas characteristics for combustion; CT design and combustion mechanisms; air contaminant emissions of CT; controlled CT emissions of nitrogen-oxides and carbon-monoxide gases using the SCR and oxidation catalysts, respectively; and, emission of volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). However, the IGCC processes are being rigorously reviewed for the system integration and reliability, and significant reduction of air contaminant emissions (including the greenhouse gases). This paper included a review of IGCC air contaminant emission rates, and various applicable regulatory requirements, such as NSR (New Source Review), NSPS (New Source Performance Standards), and MACT (Maximum Achievable Control Technology). The IGCC facility's NOX, CO, SO{sub 2}, PM, VOCs, and HAPs emission rates would be significantly low. Thus, effective, construction and installation, and operation air permits would be necessary for IGCC facilities.

  11. IGCC technology and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J [A. Ahlstrom Corporation, Karhula (Finland). Hans Ahlstrom Lab.; Lundqvist, R G [A. Ahlstrom Corporation, Helsinki (Finland); Staahl, K [Sydkraft AB, Malmoe (Sweden)

    1997-12-31

    Future energy production will be performed by advanced technologies that are more efficient, more environmentally friendly and less expensive than current technologies. Integrated gasification combined cycle (IGCC) power plants have been proposed as one of these systems. Utilising biofuels in future energy production will also be emphasised since this lowers substantially carbon dioxide emissions into the atmosphere due to the fact that biomass is a renewable form of energy. Combining advanced technology and biomass utilisation is for this reason something that should and will be encouraged. A. Ahlstrom Corporation of Finland and Sydkraft AB of Sweden have as one part of company strategies adopted this approach for the future. The companies have joined their resources in developing a biomass-based IGCC system with the gasification part based on pressurised circulating fluidized-bed technology. With this kind of technology electrical efficiency can be substantially increased compared to conventional power plants. As a first concrete step, a decision has been made to build a demonstration plant. This plant, located in Vaernamo, Sweden, has already been built and is now in commissioning and demonstration stage. The system comprises a fuel drying plant, a pressurised CFB gasifier with gas cooling and cleaning, a gas turbine, a waste heat recovery unit and a steam turbine. The plant is the first in the world where the integration of a pressurised gasifier with a gas turbine will be realised utilising a low calorific gas produced from biomass. The capacity of the Vaernamo plant is 6 MW of electricity and 9 MW of district heating. Technology development is in progress for design of plants of sizes from 20 to 120 MWe. The paper describes the Bioflow IGCC system, the Vaernamo demonstration plant and experiences from the commissioning and demonstration stages. (orig.)

  12. IGCC technology and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J. [A. Ahlstrom Corporation, Karhula (Finland). Hans Ahlstrom Lab.; Lundqvist, R.G. [A. Ahlstrom Corporation, Helsinki (Finland); Staahl, K. [Sydkraft AB, Malmoe (Sweden)

    1996-12-31

    Future energy production will be performed by advanced technologies that are more efficient, more environmentally friendly and less expensive than current technologies. Integrated gasification combined cycle (IGCC) power plants have been proposed as one of these systems. Utilising biofuels in future energy production will also be emphasised since this lowers substantially carbon dioxide emissions into the atmosphere due to the fact that biomass is a renewable form of energy. Combining advanced technology and biomass utilisation is for this reason something that should and will be encouraged. A. Ahlstrom Corporation of Finland and Sydkraft AB of Sweden have as one part of company strategies adopted this approach for the future. The companies have joined their resources in developing a biomass-based IGCC system with the gasification part based on pressurised circulating fluidized-bed technology. With this kind of technology electrical efficiency can be substantially increased compared to conventional power plants. As a first concrete step, a decision has been made to build a demonstration plant. This plant, located in Vaernamo, Sweden, has already been built and is now in commissioning and demonstration stage. The system comprises a fuel drying plant, a pressurised CFB gasifier with gas cooling and cleaning, a gas turbine, a waste heat recovery unit and a steam turbine. The plant is the first in the world where the integration of a pressurised gasifier with a gas turbine will be realised utilising a low calorific gas produced from biomass. The capacity of the Vaernamo plant is 6 MW of electricity and 9 MW of district heating. Technology development is in progress for design of plants of sizes from 20 to 120 MWe. The paper describes the Bioflow IGCC system, the Vaernamo demonstration plant and experiences from the commissioning and demonstration stages. (orig.)

  13. Corrosion of ceramics for slag removal in IGCC-power plants; Korrosion von Keramiken fuer die Fluessigascheabscheidung in IGCC-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, Denny

    2012-06-12

    Coal gasification and the subsequent production of electricity from syngas in combined-cycle powerplants allows plant efficiencies of up to 43% (LHV). Existing technologies allow up to 50% in the short term. Efficiencies beyond 50% however, require concepts and technologies that still need a certain amount of research and development. One such method to raise plant efficiencies would be a high temperature (at temperatures above the melting point of the ash) syngas cleaning. To effectively utilize the heat from the syngas and enable high turbine inlet temperatures, it is necessary to remove slag particles from the hot gas. The feasibility of such a hot syngas cleaning has been successfully demonstrated for the Pressurized Pulverized Coal Combustion (PPCC) by passing the hot gas through a bed of ceramic balls for slag removal. In order to apply this concept to IGCC powerplants the slag resistance of various ceramic materials had to be investigated under gasifying conditions. Therefore, lab-made ceramics and commercially available refractory materials where treated with liquid slag at 1600 C in a number of reducing atmospheres. At first, three synthetic slags with different basicity were used and after evaluating the results, selected materials were treated with a gasifier slag under continuous conditions. It was shown that both slag and ceramic have to be adjusted to ensure a sufficient corrosion resistance of the ceramic bed for slag removal. Furthermore, the impact of the porosity of the utilized ceramic on the corrosion resistance was shown. The composition of the reducing atmosphere (mainly the partial pressure of Oxygen) affected both physical and chemical properties of the slag via slag components that could easily be reduced or oxidized. The materials most suitable for use in slag separation were found to be dense chromium oxide and other ceramics containing a high amount of chromium oxide. [German] Mit Kohlevergasung und der anschliessenden Stromerzeugung in

  14. IGCC demonstration project status combustion engineering IGCC repowering project

    International Nuclear Information System (INIS)

    Glamuzina, R.W.; Allen, R.J.; Peletz, L.J.

    1993-01-01

    This demonstration project was originally conceived as the repowering of an existing plant facility, the Lakeside Station in Springfield, Illinois. The Owner, City Water, Light and Power (CWL ampersand P), has removed five of the original boilers and three of the original turbines. The buildings have had asbestos insulation removed and the interiors have been prepared for the construction of a single Integrated Gasification Combined Cycle (IGCC) process train that will generate a net output of 60 megawatts. The plant consists of a combined cycle (gas turbine, heat recovery steam generator, steam turbine) power train located in the existing buildings and a coal gasification system in a new building. The gasification system contains ABB CE's air-blown, entrained flow, two stage gasifier, an advanced hot gas desulfurization system by General Electric Environmental Services, Inc. and the necessary auxiliary systems. The plant is designed to produce a nominal 60 MW net output with an ambient air temperature of 95 degrees F and a cooling water temperature of 89 degrees F on either Natural Gas or Illinois No. 5 coal

  15. Heat integration and analysis of decarbonised IGCC sites

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.S.; Lopez, Y.; Campbell, G.M.; Sadhukhan, J. [University of Manchester, Manchester (United Kingdom). School of Chemical Engineering & Analytical Science

    2010-02-15

    Integrated gasification combined cycle (IGCC) power generation systems have become of interest due to their high combined heat and power (CHP) generation efficiency and flexibility to include carbon capture and storage (CCS) in order to reduce CO{sub 2} emissions. However, IGCC's biggest challenge is its high cost of energy production. In this study, decarbonised coal IGCC sites integrated with CCS have been investigated for heat integration and economic value analyses. It is envisaged that the high energy production cost of an IGCC site can be offset by maximising site-wide heat recovery and thereby improving the cost of electricity (COE) of CHP generation. Strategies for designing high efficiency CHP networks have been proposed based on thermodynamic heuristics and pinch theory. Additionally, a comprehensive methodology to determine the COE from a process site has been developed. In this work, we have established thermodynamic and economic comparisons between IGCC sites with and without CCS and a trade-off between the degree of decarbonisation and the COE from the heat integrated IGCC sites. The results show that the COE from the heat integrated decarbonised IGCC sites is significantly lower compared to IGCC sites without heat integration making application of CCS in IGCC sites economically competitive.

  16. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation...... with respect to a variety of SOFC inputs. SOFC stack operation on syn-gas is compared to operation on different coal properties and as expected there is a drop in performance, which is attributed to increased input fuel and air flow due to the lower quality of the fuel gas....

  17. U.S. and Chinese experts perspectives on IGCC technology for Chinese electric power industry

    International Nuclear Information System (INIS)

    Hsieh, B.C.B.; Wang Yingshi

    1997-11-01

    Although China is a very large and populous nation, and has one of the longest known histories in the world, it has only lately begun to seek its place among modern industrial nations. This move, precipitated by the government's relatively recently adopted strategic goals of economic development, societal reform and promotion of engagement with other industrial nations, has brought to the fore the serious situation in which the Chinese electric power industry finds itself. Owing to the advanced average age of generation facilities and the technology used in them, serious expansion and modernization of this industry needs to take place, and soon, if it is to support the rapid industrial development already taking place in China. While China does have some oil and gas, coal constitutes its largest indigenous energy supply, by far. Coal has been mined and utilized for years in China. It is used directly to provide heat for homes, businesses and in industrial applications, and used to raise steam for the generation of electricity. The presently dominant coal utilization methods are characterized by low or marginal efficiencies and an almost universal lack of pollution control equipment. Because there is so much of it, coal is destined to be China's predominant source of thermal energy for decades to come. Realizing these things--the rapidly increasing demand for more electric power than China presently can produce, the need to raise coal utilization efficiencies, and the corresponding need to preserve the environment--the Chinese government moved to commission several official working organizations to tackle these problems

  18. Strategic thinking on IGCC development in China

    International Nuclear Information System (INIS)

    Liu Hengwei; Ni Weidou; Li Zheng; Ma Linwei

    2008-01-01

    With electricity demand growing at a torrid pace-about 15% per year, faster than any other country in the world-China is fast-tracking the construction of new generation facilities, about 80% of which are coal-fired. China's total capacity in the reference scenario of World Energy Outlook 2006 (WEO2006) released by the International Energy Agency (IEA) is projected to practically 3.4 times, from 442 GW in 2004 to 1496 GW in 2030, growing at 4.8% per year on average. The vast majority of this huge generation requirement will still be met through the construction of coal power plants. Because new coal power plants built today have a long life cycle and are not easy to upgrade the technologies involved, decisions made now will have a major impact on the coal utilization mode in the coming years. Thus, the future 20 years is the strategic opportunity period of the transition of conventional coal utilization. Because the Integrated Gasification Combined Cycle (IGCC) can supply electricity, liquid fuels, hydrogen and other chemicals if needed at low pollution level, and has the potential to make carbon capture and sequestration much easier and cheaper than traditional pulverized coal boiler power plants, it should be the strategic direction for China to meet the requirements of the energy and environmental challenges. This paper makes an overview of China's energy and environmental challenges and opportunities, and describes the IGCC technology. It discusses why China should develop IGCC. What are the foundations for China to develop IGCC? What are the rational driving forces to develop IGCC in China? What is the reasonable developing path of IGCC in China?

  19. Commercialization of IGCC technology looks promising

    International Nuclear Information System (INIS)

    Smith, D.J.

    1992-01-01

    This paper reports that a major focus of the latest round of the U.S. Department of Energy's Clean Coal Technology Program was three large-scale, high-efficiency electricity generating projects which will rely on coal gasification rather than burning the coal directly. The three projects are: Toms Creek integrated gasification combined-cycle (IGCC) demonstration project. The aim of the project is to demonstrate improved coal-to-power efficiencies in an integrated gasification combined-cycle process. According to the DOE, the Toms Creek project will show that significant reductions in SO 2 and NO x emissions can be accomplished through the use of IGCC technology. On completion of the project, 107 MW of electric capacity will be added to the grid. Pinon Pine IGCC power project. The project's aim is to demonstrate that IGCC plants can be constructed at significantly lower capital costs, and with higher thermal efficiencies, than conventional power generation technologies. It will also demonstrate the effectiveness of hot gas cleanup for low-sulfur western coals. Wasbash River coal gasification repowering project

  20. Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

    International Nuclear Information System (INIS)

    Abaimov, N A; Osipov, P V; Ryzhkov, A F

    2016-01-01

    In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by “NPO CKTI” JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air. (paper)

  1. Thermal and sintering characterization of IGCC slag

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, A.; Iglesias, I.; Aineto, M.; Romero, M.; Rincon, J.M. [University of Castilla La Mancha, Ciudad Real (Spain)

    2002-07-01

    IGCC slag is a vitreous residual product from the new induction gasification combined cycle gasification thermal power plants. In order to characterize this waste as secondary raw material for the production of glasses and glass-ceramics as construction materials, slag from the Puertollano, Ciudad Real, Spain power plants was thermally investigated. After controlled heating this waste gives rise to hematite, anorthite, and cristobalite crystallized materials.

  2. Puertollano IGCC plant. Present position and future competitiveness

    Energy Technology Data Exchange (ETDEWEB)

    Pedro Casero; Francisco Garcia-Pena

    2006-07-01

    This paper discusses the current status of the Puertollano 350 MW IGCC demonstration power plant in Spain. The experience provided by the operation of this plant during the last years is described, focussing on the core systems of the plant (gasifier, gas cleaning and gas turbines). Bottlenecks and weak points related to these systems are identified, along with the improvements. The production of hydrogen from coal at an IGCC plant is also discussed. 9 figs., 2 tabs.

  3. Demonstration of IGCC features - plant integration and syngas combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, F.; Huth, M.; Karg, J.; Schiffers, U. [Siemens AG Power Generation (KWU), Erlanger/Muelheim (Germany)

    2000-07-01

    Siemens is involved in three IGCC plants in Europe that are currently in operation. Against the background of the Puertollano and Buggenum plants, some of the specific new features of fully integrated IGCC power plants are discussed, including: requirements and design features of the gas turbine syngas supply system; gas turbine operating experience with air extraction for the air separation unit from the gas turbine air compressor; and design requirements and operational features of the combustion system. 7 refs., 17 figs., 1 tab.

  4. The slag from ELCOGAS IGCC thermal power plant as raw material for the synthesis of glass-ceramic materials. Part I: Thermal behavior of the IGCC slag and synthesis of the parent glass.

    Energy Technology Data Exchange (ETDEWEB)

    Aineto, M.; Acosta, A. [University of Castilla La Mancha, Ciudad Real (Spain)

    2005-12-01

    We report here the results of the first phase of investigation on the melting behavior of the IGCC slag, and the use of this slag as raw component to produce glass ceramics. The vitrifying mixture named ECSCP, is composed of 40% slag, 30% glass cullet and 30% precipitated calcium carbonate obtained as a by-product in a sugar refining plant. This mixture was melted at 1450{sup o}C to obtain the ECSCP parent glass, that was then characterized and its crystallization kinetics studied by thermal analysis. The ECSCP glass exhibit a surface mechanism of crystallization, and will be used to produce anorthite/wollastonite glass ceramics in the second part of the investigation.

  5. Distributed Power Flow Controller

    NARCIS (Netherlands)

    Yuan, Z.

    2010-01-01

    In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of

  6. Technical and economic assessments commercial success for IGCC technology in China

    International Nuclear Information System (INIS)

    Xiong, T.

    1998-01-01

    The experiences gained from several Integrated Gasification Combined Cycle (IGCC) demonstration plants operating in the US and Europe facilitate commercial success of this advanced coal-based power generation technology. However, commercialization of coal-based IGCC technology in the West, particularly in the US, is restricted due to the low price of natural gas. On the contrary, in China--the largest coal producer and consumer in the world--a lack of natural gas supply, strong demand for air pollution control and relatively low costs of manufacturing and construction provide tremendous opportunities for IGCC applications. The first Chinese IGCC demonstration project was initiated in 1994, and other potential IGCC projects are in planning. IGCC applications in re-powering, fuel switching and multi-generation also show a great market potential in China. However, questions for IGCC development in China remain; where are realistic opportunities for IGCC projects and how can these opportunities be converted into commercial success? The answers to these questions should focus on the Chinese market needs and emphasize economic benefits, not just clean, or power. High price of imported equipment, high financing costs, and the technical risk of first-of-a-kind installation barricade IGCC development in China. This paper presents preliminary technical and economic assessments for four typical IGCC applications in the Chinese marketplace: central power station, fuel switching, re-powering, and multi-generation. The major factors affecting project economics--such as plant cost, financing, prices of fuel and electricity and operating capacity factor--are analyzed. The results indicate that well-proven technology for versatile applications, preferred financing, reduction of the plant cost, environmental superiority and appropriate project structure are the key for commercial success of IGCC in China

  7. Pinon Pine IGCC project status

    International Nuclear Information System (INIS)

    Higginbotham, E.B.; Lamarre, L.J.; Glazer, M.

    1993-01-01

    Sierra Pacific Power Company (SPPCo) intends to build the Pinon Pine Power Project, an integrated coal gasification combined cycle (IGCC) plant at its Tracy Power Station near Reno, Nevada. The plant will burn approximately 800 tons of coal per day to generate electricity in a base load application. The Pinon Project was selected by the U.S. Department of Energy (DOE) for funding under Round IV of the Clean Coal Technology Program. The project will demonstrate the use of the KRW agglomerating fluidized bed gasifer operating in the air blown mode. Hot gas cleanup consisting of particulate and sulfur removal will also be demonstrated. The Cooperative Agreement between SPPCo and the DOE was executed in August 1992. Foster Wheeler USA Corporation (FWUSA) will provide engineering and construction management services. The M.W. Kellogg Company (MWK) will provide engineering of the gasifer and hot gas cleanup systems. A discussion of project progress since the 1992 Clean Coal Technology Conference, design and economic considerations, and current project status is presented

  8. Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

    International Nuclear Information System (INIS)

    Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

    2014-01-01

    Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

  9. IGCC based on proven technology developing towards 50% efficiency mark

    Energy Technology Data Exchange (ETDEWEB)

    Goudappel, E.; Berkhout, M. [Jacobs Consultancy, Leiden (Netherlands)

    2006-07-01

    In this paper the achievements made over the last 10 years in terms of reliability, load following and efficiency improvement potential at the Buggenum IGCC plant, are presented. Also the air side heat integration and its pros and cons are discussed. Additionally future business opportunities adjacent to the power production itself and the view on coal gasification in the near future are provided. The results are discussed and it is shown that with 'proven' gasifier and gas treatment technology, overall efficiency exceeding 47% (LHV basis) can be reached. It puts this technical potential in perspective and describes the view on interesting business opportunities around IGCC projects. 5 figs., 3 tabs.

  10. Advanced IGCC-Hypogen concepts for a developing hydrogen market

    Energy Technology Data Exchange (ETDEWEB)

    Starr, F.; Cormos, C.-C.; Tzimas, E.; Brown, A. [European Commission, Petten (Netherlands). DG Joint Research Centre, Institute for Energy

    2007-07-01

    With FP6 the EU is funding a project called 'Dynamis' which aims to design plants to generate electricity, plus a limited amount of hydrogen from fossil fuels, in which the CO{sub 2} is captured and stored underground. Such plants have been characterised as being of the 'HYPOGEN' type since they generate both hydrogen and electric power. As the hydrogen market develops IGCC-Hypogen based systems will need to produce much greater amounts of hydrogen. It is also desirable that such plants should be able to vary the proportion of hydrogen-to-electricity. This will enable IGCC-Hypogen plants to load follow and two-shift as electricity demand from the grid changes. Such variations in power output are not always practical with existing designs of electricity-only IGCCs. This paper reviews the technical issues involved in providing a high-flexibility IGCC-Hypogen plant. Three such concepts are discussed (1) very limited flexibility in which the changes from a fixed hydrogen-electricity ratio concept are minor, (2) moderate level of flexibility in which the limit is imposed by the CCGT gas turbine turndown (3) complete flexibility, the plant being able produce the energy as all-electricity or all-hydrogen. 9 refs., 2 figs., 1 tab.

  11. Optimal Power Flow Pursuit

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano; Simonetto, Andrea

    2018-03-01

    This paper considers distribution networks featuring inverter-interfaced distributed energy resources, and develops distributed feedback controllers that continuously drive the inverter output powers to solutions of AC optimal power flow (OPF) problems. Particularly, the controllers update the power setpoints based on voltage measurements as well as given (time-varying) OPF targets, and entail elementary operations implementable onto low-cost microcontrollers that accompany power-electronics interfaces of gateways and inverters. The design of the control framework is based on suitable linear approximations of the AC power-flow equations as well as Lagrangian regularization methods. Convergence and OPF-target tracking capabilities of the controllers are analytically established. Overall, the proposed method allows to bypass traditional hierarchical setups where feedback control and optimization operate at distinct time scales, and to enable real-time optimization of distribution systems.

  12. Structural power flow measurement

    Energy Technology Data Exchange (ETDEWEB)

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  13. THERMAL AND SINTERING CHARACTERIZATION OF A IGCC SLAG

    OpenAIRE

    Acosta, Anselmo; Iglesias, Isabel; Aineto, Mónica; Romero, Maximina; Rincón López, Jesús María

    2002-01-01

    IGCC slag is a vitreous residual product from the new induction gasification combined cycle gasification thermal power plants. In order to characterize this waste as secondary new material for the production of new glasses and glass-ceramics as construction materials; this slag from the Puertollano, Ciudad Real, Spain power plants has been fully thermally investigated. After controlled heating this waste gives rise to hematite, anorthite, and cristobalite crystallized materials.

  14. The future of integrated coal gasification combined cycle power plants

    International Nuclear Information System (INIS)

    Mueller, R.; Termuehlen, H.

    1991-01-01

    This paper examines the future of integrated coal gasification combined cycle (IGCC) power plants as affected by various technical, economical and environmental trends in power generation. The topics of the paper include a description of natural gas-fired combined cycle power plants, IGCC plants, coal gasifier concepts, integration of gasifiers into combined cycle power plants, efficiency, environmental impacts, co-products of IGCC power plants, economics of IGCC power plants, and a review of IGCC power plant projects

  15. Air toxics emissions from an IGCC process

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Norrbacka, P. [Enviropower Inc., Espoo (Finland); Hinderson, A. [Vattenfall (Sweden); Rosenberg, R.; Zilliacus, R.; Kurkela, E.; Nieminen, M. [VTT Energy, Espoo (Finland); Hoffren, H. [IVO International Oy, Vantaa (Finland)

    1996-12-01

    The so-called simplified coal gasification combined cycle process, incorporating air gasification and hot gas cleanup, promises high power generation efficiency in an environmentally acceptable manner. Increasingly more stringent environmental regulations have focused attention on the emissions of not only SO{sub 2} and NO{sub x} but also on the so-called air toxics which include a number of toxic trace elements. As result of recent amendments to the United States Clean Air Act, IGCC emissions of eleven trace elements: antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium - as well as the radionuclides uranium and thorium may be regulated. Similarly, air missions standards in Europe include a limit of 0.05 mg Nm{sup 3} for mercury and cadmium and 1.0 3/Nm{sup 3} for other class I trace elements. A suitable sampling/measuring system has been developed in this project (in cooperation with Imatran Voima Oy, Electric Power Research Institute (EPRI) and Radian Cooperation) which will be used in the pressurized gasification tests. This will enable an accurate measurement of the volatilized trace element species, at high temperature and pressure, which may be found in the vapour phase. Models are being developed that can be used to determine not only the chemical equilibrium composition of gaseous, liquid and solid phases, but also possible interactions of the gaseous species with aerosol particles and surfaces, These should be used to more accurately assess the impact of the toxic trace metals emitted from the simplified IGCC system

  16. Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, A.; Bonalumi, D.; Lozza, G.

    2013-01-01

    Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

  17. Assessment of oxy-fuel, pre- and post-combustion-based carbon capture for future IGCC plants

    International Nuclear Information System (INIS)

    Kunze, Christian; Spliethoff, Hartmut

    2012-01-01

    Highlights: ► Hot gas cleanup is a highly favorable technology for all selected IGCC concepts. ► Proposed high pressure IGCC with membrane reactor enables direct CO 2 condensation. ► IGCC with OTM and carbonate looping enable significant synergy effects. ► Combining IGCC and oxy-fuel is technically challenging but energetically favorable. ► All selected IGCC concepts are able to realize CO 2 capture rates up to 99%. -- Abstract: Environmental damage due to the emission of greenhouse gases from conventional coal-based power plants is a growing concern. Various carbon capture strategies to minimize CO 2 emissions are currently being investigated. Unfortunately, the efficiency drop due to de-carbonization is still significant and the capture rate is limited. Therefore three future hard coal IGCC concepts are assessed here, applying emerging technologies and various carbon capture approaches. The advanced pre-combustion capture concept is based on hot gas clean-up, membrane-enhanced CO conversion and direct CO 2 condensation. The concept reached a net efficiency of 45.1% (LHV), representing an improvement of 6.46% compared to the conventional IGCC base case. The second IGCC concept, based on post-combustion capture via calcination–carbonation loops, hot gas clean-up and oxygen membranes, showed a net efficiency of 45.87% (LHV). The third IGCC concept applies hot gas clean-up and combustion of the unconverted fuel gas using pure oxygen. The oxygen is supplied by an integrated oxygen membrane. The combination of IGCC and oxy-fuel process reached a net efficiency of 45.74% (LHV). In addition to their increased efficiency, all of the concepts showed significantly improved carbon capture rates up to 99%, resulting in virtually carbon-free fossil power plants.

  18. Kemper County IGCC (tm) Project Preliminary Public Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Matt; Rush, Randall; Madden, Diane; Pinkston, Tim; Lunsford, Landon

    2012-07-01

    The Kemper County IGCC Project is an advanced coal technology project that is being developed by Mississippi Power Company (MPC). The project is a lignite-fueled 2-on-1 Integrated Gasification Combined-Cycle (IGCC) facility incorporating the air-blown Transport Integrated Gasification (TRIG™) technology jointly developed by Southern Company; Kellogg, Brown, and Root (KBR); and the United States Department of Energy (DOE) at the Power Systems Development Facility (PSDF) in Wilsonville, Alabama. The estimated nameplate capacity of the plant will be 830 MW with a peak net output capability of 582 MW. As a result of advanced emissions control equipment, the facility will produce marketable byproducts of ammonia, sulfuric acid, and carbon dioxide. 65 percent of the carbon dioxide (CO{sub 2}) will be captured and used for enhanced oil recovery (EOR), making the Kemper County facility’s carbon emissions comparable to those of a natural-gas-fired combined cycle power plant. The commercial operation date (COD) of the Kemper County IGCC plant will be May 2014. This report describes the basic design and function of the plant as determined at the end of the Front End Engineering Design (FEED) phase of the project.

  19. Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Yackly

    2005-12-01

    turbine combustion systems. This task was refocused to address pre-mixed combustion phenomenon for IGCC applications. The work effort on this task was shifted to another joint GE Energy/DOE-NETL program investigation, High Hydrogen Pre-mixer Designs, as of April 1, 2004. Task 4--Information Technology (IT) Integration: The fourth task was originally to demonstrate Information Technology (IT) tools for advanced technology coal/IGCC powerplant condition assessment and condition based maintenance. The task focused on development of GateCycle. software to model complete-plant IGCC systems, and the Universal On-Site Monitor (UOSM) to collect and integrate data from multiple condition monitoring applications at a power plant. The work on this task was stopped as of April 1, 2004.

  20. Sulphur removal in IGCC projects

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F. (Parsons (United Kingdom))

    1998-01-01

    The technology for recovering elemental sulphur from H[sub 2]S bearing gases is well established. The modified Claus Process is the principal work-horse in sulphur recovery and can customarily achieve conversion efficiencies of 95% or better. Nowadays, such a level of recovery is no longer sufficient in most instances and sulphur recovery facility must then include some form of enhanced recovery, usually by treating the Claus tail gas. A number of processes have been introduced to enable the overall recovery to be increased. Recoveries in excess of 99% are both feasible and economic. Use of oxygen in place has become very popular in cases where oxygen is available cheaply or where capacity increases are designed. Most IGCC projects needing an air separation plant would automatically benefit from extending the use of oxygen to the sulphur recovery plant. The most popular route to minimising sulphur emissions in the context of IGCC projects has involved an oxygen based Claus plant followed by tail gas hydrogenation, hydrogen sulphide recovery and its recycle to the Claus section. The recovery of H[sub 2]S from the Claus tail gas can be integrated with the main gas treating system in the gasification plant. The cost advantage of doing so is significant. Parsons has been involved with the technology since 1949 and has been responsible for developments such as the ammonia burning Claus and jointly with Unocal, the BSRP tail gas process and Selectox processes. Recent innovations in response changing environmental and production requirements have included catalytic and tail gas processes which reduce sulphur emissions. 6 figs., 2 tabs.

  1. Sulphur removal in IGCC projects

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F. [Parsons (United Kingdom)

    1998-12-31

    The technology for recovering elemental sulphur from H{sub 2}S bearing gases is well established. The modified Claus Process is the principal work-horse in sulphur recovery and can customarily achieve conversion efficiencies of 95% or better. Nowadays, such a level of recovery is no longer sufficient in most instances and sulphur recovery facility must then include some form of enhanced recovery, usually by treating the Claus tail gas. A number of processes have been introduced to enable the overall recovery to be increased. Recoveries in excess of 99% are both feasible and economic. Use of oxygen in place has become very popular in cases where oxygen is available cheaply or where capacity increases are designed. Most IGCC projects needing an air separation plant would automatically benefit from extending the use of oxygen to the sulphur recovery plant. The most popular route to minimising sulphur emissions in the context of IGCC projects has involved an oxygen based Claus plant followed by tail gas hydrogenation, hydrogen sulphide recovery and its recycle to the Claus section. The recovery of H{sub 2}S from the Claus tail gas can be integrated with the main gas treating system in the gasification plant. The cost advantage of doing so is significant. Parsons has been involved with the technology since 1949 and has been responsible for developments such as the ammonia burning Claus and jointly with Unocal, the BSRP tail gas process and Selectox processes. Recent innovations in response changing environmental and production requirements have included catalytic and tail gas processes which reduce sulphur emissions. 6 figs., 2 tabs.

  2. Siemens sees a future for IGCC - and now it has the technology

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, C.; Hannemann, F. [Siemens Fuel Gasification Technology, Freiberg (Germany)

    2007-10-15

    About 18 months ago Siemens became a key player in the gasification business through its acquisition of Freiberg based Future Energy and its GSP entrained flow technology, now called SFG (Siemens Fuel Gasification). Developed at Schwarze Pumpe in Eastern Germany over many years, a particular attraction of the process is its ability to use low rank fuels such as lignite, with a robust gasifier wall concept a 'cooling screen' that avoids the use of troublesome refractories. The article explains the SFG gasifier technology. It is ideally suited for coal-fueled IGCC power plants with integrated CO{sub 2} capture, especially for low-rank fuels. SFG has been ordered or pre-selected for a number of projects in China, North America and elsewhere. 5 figs.

  3. Load flow optimization and optimal power flow

    CERN Document Server

    Das, J C

    2017-01-01

    This book discusses the major aspects of load flow, optimization, optimal load flow, and culminates in modern heuristic optimization techniques and evolutionary programming. In the deregulated environment, the economic provision of electrical power to consumers requires knowledge of maintaining a certain power quality and load flow. Many case studies and practical examples are included to emphasize real-world applications. The problems at the end of each chapter can be solved by hand calculations without having to use computer software. The appendices are devoted to calculations of line and cable constants, and solutions to the problems are included throughout the book.

  4. IGCC - fuel-flexible technology for the future

    Energy Technology Data Exchange (ETDEWEB)

    Karg, J.; Hannemann, F. [Siemens AG Power Generation, Erlangen (Germany)

    2004-07-01

    According to IEA's World Energy Investment Outlook 2003 the electricity sector will dominate with about 60% of the total investment requirements expected until 2030 for worldwide energy-supply infrastructure. Around 45% of the capital needed for the electricity sector will be for power generation. The investment will be needed for capacity additions and to replace existing older facilities. According to the estimates the global primary energy demand is projected to grow by two thirds over the next three decades and electricity demand is expected to double by 2030. The natural gas for power generation is projected to increase significantly, but coal will remain the largest source of electricity generation throughout the projection period. These trends must be seen against the background that environmental regulations, are becoming tighter, and that environmental legislation will increasingly address greenhouse gas emissions. The necessity for more efficient use of primary energies in combination with more stringent environmental regulations for fossil-fuelled power plants therefore pushes concepts with increased efficiencies and reduced CO{sub 2} emissions, respectively. Since significant reduction of CO{sub 2} emissions cannot only be achieved via increased efficiencies or application of fuels with low carbon content, CO{sub 2} removal options also need to be considered for future power plant configurations. Considering this, IGCC is again one of the most promising solutions which are of relevance in this context. However, these new IGCC applications require further overall a plant concept and component development efforts. One essential step for performance improvement of future IGCC applications is to further develop syngas capabilities of advanced gas turbines, thereby considering the experience and lessons learned from operational plants. 11 refs., 7 figs., 5 tabs.

  5. Optimal Power Flow Control by Rotary Power Flow Controller

    Directory of Open Access Journals (Sweden)

    KAZEMI, A.

    2011-05-01

    Full Text Available This paper presents a new power flow model for rotary power flow controller (RPFC. RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST and two conventional (series and shunt transformers. Structurally, an RPST consists of two windings (stator and rotor windings. The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.

  6. Briefing Book, Interagency Geothermal Coordinating Council (IGCC) Meeting of April 28, 1988

    Energy Technology Data Exchange (ETDEWEB)

    None

    1988-04-28

    The IGCC of the U.S. government was created under the intent of Public Law 93-410 (1974) to serve as a forum for the discussion of Federal plans, activities, and policies that are related to or impact on geothermal energy. Eight Federal Departments were represented on the IGCC at the time of this meeting. The main presentations in this report were on: Department of Energy Geothermal R&D Program, the Ormat binary power plant at East Mesa, CA, Potential for direct use of geothermal at Defense bases in U.S. and overseas, Department of Defense Geothermal Program at China Lake, and Status of the U.S. Geothermal Industry. The IGCC briefing books and minutes provide a historical snapshot of what development and impact issues were important at various time. (DJE 2005)

  7. [Tampa Electric Company IGCC project]. 1996 DOE annual technical report, January--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project uses a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,000 tons per day of coal to syngas. The gasification plant is coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 BTUs/cf (HHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product. Approximately 10% of the raw, hot syngas at 900 F is designed to pass through an intermittently moving bed of metal-oxide sorbent which removes sulfur-bearing compounds from the syngas. PPS-1 will be the first unit in the world to demonstrate this advanced metal oxide hot gas desulfurization technology on a commercial unit. The emphasis during 1996 centered around start-up activities.

  8. CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY

    International Nuclear Information System (INIS)

    Ravi Prasad

    2000-01-01

    The objective of this program is to conduct a technology development program to advance the state-of-the-art in ceramic Oxygen Transport Membranes (OTM) to the level required to produce step change improvements in process economics, efficiency, and environmental benefits for commercial IGCC systems and other applications. The IGCC program is focused on addressing key issues in materials, processing, manufacturing, engineering and system development that will make the OTM a commercial reality. The objective of the OTM materials development task is to identify a suitable material that can be formed into a thin film to produce the target oxygen flux. This requires that the material have an adequate permeation rate, and thermo-mechanical and thermo-chemical properties such that the material is able to be supported on the desired substrate and sufficient mechanical strength to survive the stresses involved in operation. The objective of the composite OTM development task is to develop the architecture and fabrication techniques necessary to construct stable, high performance, thin film OTMs supported on suitable porous, load bearing substrates. The objective of the process development task of this program to demonstrate the program objectives on a single OTM tube under test conditions simulating those of the optimum process cycle for the power plant

  9. Usefulness of DC power flow for active power flow analysis with flow controlling devices

    NARCIS (Netherlands)

    Van Hertem, D.; Verboomen, J.; Purchala, K.; Belmans, R.; Kling, W.L.

    2006-01-01

    DC power flow is a commonly used tool for contingency analysis. Recently, due to its simplicity and robustness, it also becomes increasingly used for the real-time dispatch and techno-economic analysis of power systems. It is a simplification of a full power flow looking only at active power.

  10. ConocoPhillips Sweeny IGCC/CCS Project

    Energy Technology Data Exchange (ETDEWEB)

    Paul Talarico; Charles Sugg; Thomas Hren; Lauri Branch; Joseph Garcia; Alan Rezigh; Michelle Pittenger; Kathleen Bower; Jonathan Philley; Michael Culligan; Jeremy Maslen; Michele Woods; Kevin Elm

    2010-06-16

    Under its Industrial Carbon Capture and Sequestration (ICCS) Program, the United States (U.S.) Department of Energy (DOE) selected ConocoPhillips Company (ConocoPhillips) to receive funding through the American Recovery and Reinvestment Act (ARRA) of 2009 for the proposed Sweeny Integrated Gasification Combined Cycle (IGCC)/Carbon Capture and Storage (CCS) Project (Project) to be located in Brazoria County, Texas. Under the program, the DOE is partnering with industry to demonstrate the commercial viability and operational readiness of technologies that would capture carbon dioxide (CO{sub 2}) emissions from industrial sources and either sequester those emissions, or beneficially reuse them. The primary objective of the proposed Project was to demonstrate the efficacy of advanced technologies that capture CO{sub 2} from a large industrial source and store the CO{sub 2} in underground formations, while achieving a successful business venture for the entity (entities) involved. The Project would capture 85% of the CO{sub 2} produced from a petroleum coke (petcoke) fed, 703 MWnet (1,000 MWgross) IGCC power plant, using the ConocoPhillips (COP) proprietary and commercially proven E-Gas{trademark} gasification technology, at the existing 247,000 barrel per day COP Sweeny Refinery. In addition, a number of other commercially available technologies would be integrated into a conventional IGCC Plant in a unique, efficient, and reliable design that would capture CO{sub 2}. The primary destination for the CO{sub 2} would be a depleted natural gas field suitable for CO{sub 2} storage ('Storage Facility'). COP would also develop commercial options to sell a portion of the IGCC Plant's CO{sub 2} output to the growing Gulf Coast enhanced oil recovery (EOR) market. The IGCC Plant would produce electric power for sale in the Electric Reliability Council of Texas Houston Zone. The existing refinery effluent water would be treated and reused to fulfill all process

  11. Commercial gasifier for IGCC applications study report

    Energy Technology Data Exchange (ETDEWEB)

    Notestein, J.E.

    1990-06-01

    This was a scoping-level study to identify and characterize the design features of fixed-bed gasifiers appearing most important for a gasifier that was to be (1) potentially commercially attractive, and (2) specifically intended for us in integrated coal gasification/combined-cycle (IGCC) applications. It also performed comparative analyses on the impact or value of these design features and on performance characteristics options of the whole IGCC system since cost, efficiency, environmental traits, and operability -- on a system basis -- are what is really important. The study also reviewed and evaluated existing gasifier designs, produced a conceptual-level gasifier design, and generated a moderately advanced system configuration that was utilized as the reference framework for the comparative analyses. In addition, technical issues and knowledge gaps were defined. 70 figs., 31 tabs.

  12. Api Energia IGCC plant is fully integrated with refinery

    Energy Technology Data Exchange (ETDEWEB)

    Del Bravo, R. [api Energia, Rome (Italy); Trifilo, R. [ABB Sadelmi, Milan (Italy); Chiantore, P.V. [api anonima petroli Italiania Spa, Rome (Italy); Starace, F. [ABB Power Generation, Baden (Switzerland); O`Keefe, L.F. [Texico, White Plains (United States)

    1998-06-01

    The api Energia integrated gasification combined cycle (IGCC) plant being built at Falconara Marittima, on Italy`s Adriatic coast, is one of the three IGCC plants under construction in Italy following the liberalization of the electricity production sector. The plant will take 59.2 t/h of high sulphur heavy oil produced by the Falconara refinery, convert it to syngas and use the gas to generate 280 MW of electricity, plus steam and other gases for use in the refinery. The IGCC plant will be highly integrated into the refining process, with a large number of interchanges between the IGCC unit and the rest of the refinery. (author)

  13. The United States of America and the People`s Republic of China experts report on integrated gasification combined-cycle technology (IGCC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    A report written by the leading US and Chinese experts in Integrated Gasification Combined Cycle (IGCC) power plants, intended for high level decision makers, may greatly accelerate the development of an IGCC demonstration project in the People`s Republic of China (PRC). The potential market for IGCC systems in China and the competitiveness of IGCC technology with other clean coal options for China have been analyzed in the report. Such information will be useful not only to the Chinese government but also to US vendors and companies. The goal of this report is to analyze the energy supply structure of China, China`s energy and environmental protection demand, and the potential market in China in order to make a justified and reasonable assessment on feasibility of the transfer of US Clean Coal Technologies to China. The Expert Report was developed and written by the joint US/PRC IGCC experts and will be presented to the State Planning Commission (SPC) by the President of the CAS to ensure consideration of the importance of IGCC for future PRC power production.

  14. Power flow control using quadrature boosters

    Science.gov (United States)

    Sadanandan, Sandeep N.

    A power system that can be controlled within security constraints would be an advantage to power planners and real-time operators. Controlling flows can lessen reliability issues such as thermal limit violations, power stability problems, and/or voltage stability conditions. Control of flows can also mitigate market issues by reducing congestion on some lines and rerouting power to less loaded lines or onto preferable paths. In the traditional control of power flows, phase shifters are often used. More advanced methods include using Flexible AC Transmission System (FACTS) Controllers. Some examples include Thyristor Controlled Series Capacitors, Synchronous Series Static Compensators, and Unified Power Flow Controllers. Quadrature Boosters (QBs) have similar structures to phase-shifters, but allow for higher voltage magnitude during real power flow control. In comparison with other FACTS controllers QBs are not as complex and not as expensive. The present study proposes to use QBs to control power flows on a power system. With the inclusion of QBs, real power flows can be controlled to desired scheduled values. In this thesis, the linearized power flow equations used for power flow analysis were modified for the control problem. This included modifying the Jacobian matrix, the power error vector, and calculating the voltage injected by the quadrature booster for the scheduled real power flow. Two scenarios were examined using the proposed power flow control method. First, the power flow in a line in a 5-bus system was modified with a QB using the method developed in this thesis. Simulation was carried out using Matlab. Second, the method was applied to a 30-bus system and then to a 118-bus system using several QBs. In all the cases, the calculated values of the QB voltages led to desired power flows in the designated line.

  15. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and

  16. Kotka ecopower IGCC-project, the attempt to transfer the biocycle project to Finland

    International Nuclear Information System (INIS)

    Salo, K.

    1998-01-01

    The Danish utilities Elsam and Elkraft planned to build a small (7 MW e ) IGCC-plant in Denmark, called Biocycle Project, based on the gasification and gas clean-up technology of Enviropower Inc. EU/THERMIE program committed to finance part of the investment. The project, however, was not feasible due to the difficulty of finding a suitable customer and sufficient amount of reasonably priced biomass. For this reason a new host and site was found for the Biocycle project. The new site was in Kotka, Finland, where Kotka Energy Ltd., the Energy Board of the City of Kotka acted as the main partner. The fuel of the IGCC project would have been sugar mill wood residue from Xyrofin Inc. During the feasibility investigation (project definition phase) Xyrofin Inc. made the decision to change the production process which eliminated the wood waste production. Without no-cost fuel and due to the low electricity price in Finland the small size IGCC power plant proved not to be feasible. (author)

  17. CO2 control technology effects on IGCC plant performance and cost

    International Nuclear Information System (INIS)

    Chen Chao; Rubin, Edward S.

    2009-01-01

    As part of the USDOE's Carbon Sequestration Program, an integrated modeling framework has been developed to evaluate the performance and cost of alternative carbon capture and storage (CCS) technologies for fossil-fueled power plants in the context of multi-pollutant control requirements. This paper uses the newly developed model of an integrated gasification combined cycle (IGCC) plant to analyze the effects of adding CCS to an IGCC system employing a GE quench gasifier with water gas shift reactors and a Selexol system for CO 2 capture. Parameters of interest include the effects on plant performance and cost of varying the CO 2 removal efficiency, the quality and cost of coal, and selected other factors affecting overall plant performance and cost. The stochastic simulation capability of the model is also used to illustrate the effect of uncertainties or variability in key process and cost parameters. The potential for advanced oxygen production and gas turbine technologies to reduce the cost and environmental impacts of IGCC with CCS is also analyzed

  18. Air toxics emission from an IGCC process

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W; Hovath, A [Carbona Inc, Helsinki (Finland); Hinderson, A [Vattenfall Utveckling (Sweden); Nykaenen, J; Hoffren, H [Imatran Voima Oy, Vantaa (Finland); Nieminen, M; Kurkela, E [VTT, Espoo (Finland)

    1997-10-01

    The emissions of 12 toxic trace element from a coal-fired IGCC plant were calculated based on thermodynamic equilibrium in the gas phase and some of the results published. The theoretical calculations were extended to include some other fuels as well as mixture of some of these fuels. The combustion of the product gas in the gas turbine is also considered. These simulations correspond to gasification of the fuel at 850-1050 deg C (depending on the fuel) and 1823 bar pressure. The gas composition was taken from the measured data as far as possible. In the absence of experimental data, a computer code developed for the U-Gas gasifier was used to determine the fuel gas composition. The gas was then cooled to 550 deg C in the gas cooler and filtered at this same temperature and burned in the gas turbine with an air ratio of 3.2. The results of these simulations are compared with the measured data of an experimental program designed to measure the emissions of a few selected trace elements from a 15 MW,h pressurized fluidized bed gasification pilot plant. The pilot plant was equipped with an advanced hot gas cleanup train which includes a two fluidized-bed reactor system for high-temperature, high-pressure external sulfur removal and a filtration unit housing porous, rigid ceramic candle filters. The trace element concentrations in the fuel, bottom ash, and filter ash are determined and the results compared with EPA regulatory levels

  19. Market drivers and challenges for gasification-based power plants in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Juergen Karg; Frank Hannemann [Siemens Power Generation (PG) (Germany)

    2006-07-01

    The paper begins by examining the present situation and future trends in the power generation market, before discussing existing IGCC plants and present market activities. IGCC plants in which Siemens are involved are given and coal-based IGCC applications are described. Finally improvement potential of IGCC, and technologies towards zero emission plants (including CO{sub 2} capture and sequestration) are discussed. 19 refs., 7 figs., 3 tabs.

  20. Recent operating experience and improvement of commercial IGCC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    IGCC has today reached a status where experience is available from first and second generation plants, built in the 1970s/1980s and in the 1990s respectively, as commercial-scale demonstration plants for coal-based applications. These plants feature variations on gasification technology and subsequent environmental controls and in operating them a number of technical and commercial lessons have been learned that will help to improve the next generation of IGCC projects. The report reviews and summarises the state-of-the-art and operating experience of several commercial IGCC plants worldwide, setting out the lessons learned and plans for future development embracing such issues as the changes or modifications to plant made to overcome the operational problems and to improve the reliability and availability of the plant. Since IGCC is considered a 'capture ready' technology for CO2 abatement, the current status with regard to the incorporation of carbon capture and storage systems (CCS) has been reviewed. Finally, the report outlines the issues associated with assessing the risks in commercialising IGCC plant.

  1. Effective utilization of fossil fuels for low carbon world -- IGCC and high performance gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Hiromi; Hashimoto, Takao; Sakamoto, Koichi; Komori, Toyoaki; Kishine, Takashi; Shiozaki, Shigehiro

    2010-09-15

    The reduction of greenhouse-gas emissions is required to minimize the effect of hydrocarbon based power generation on global warming. In pursue of this objective, Mitsubishi Heavy Industries is dedicating considerable efforts on two different ways to reduce the environmental impact. The first one involves gas turbine performance improvement by raising firing temperature for Natural-gas and LNG applications. In this regard, the latest J class gas turbine was designed to operate at 1600 deg C and expected combined cycle efficiency in excess of 60%. The other approach involves the use of Integrated Gasification Combined Cycle (IGCC) plants to burn solid fuel like coal.

  2. Modeling and assessment of future IGCC plant concepts with CO{sub 2} capture; Simulation und Bewertung zukuenftiger IGCC-Kraftwerkskonzepte mit CO{sub 2}-Abtrennung

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, Christian A.

    2012-07-13

    The thesis focuses on the assessment of efficiency potential of future IGCC plants with CO{sub 2} capture. Starting point is a comprehensive analysis (thermodynamic, economic and exergy) of a state of the art IGCC. Additionally, five future IGCC concepts are proposed and evaluated for their efficiency potential in the mid- and long-term. The concepts showed significantly higher efficiencies up to approximately 60% and enable an almost CO{sub 2}-free operation.

  3. Power laws and fragility in flow networks.

    Science.gov (United States)

    Shore, Jesse; Chu, Catherine J; Bianchi, Matt T

    2013-01-01

    What makes economic and ecological networks so unlike other highly skewed networks in their tendency toward turbulence and collapse? Here, we explore the consequences of a defining feature of these networks: their nodes are tied together by flow. We show that flow networks tend to the power law degree distribution (PLDD) due to a self-reinforcing process involving position within the global network structure, and thus present the first random graph model for PLDDs that does not depend on a rich-get-richer function of nodal degree. We also show that in contrast to non-flow networks, PLDD flow networks are dramatically more vulnerable to catastrophic failure than non-PLDD flow networks, a finding with potential explanatory power in our age of resource- and financial-interdependence and turbulence.

  4. Modelling of electrical power systems for power flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cogo, Joao Roberto [Escola Federal de Engenharia de Itajuba, MG (Brazil)

    1994-12-31

    The industry systems in Brazil are responsible for a consumption of over 50% (fifty per cent) of the total electrical power generated: therefore, they are import loads in power flow studies, and their modeling should be as much the best. Usually, in power flow studies, the industry systems are modeled by taking the influence of the power (active and reactive) and of the current on the voltage into account. Since the inducting motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversize, it is proposed to represent the industry systems as a function of the characteristic of power on shaft versus voltage into account. Since the induction motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversized, it is proposed to represent the industry systems as a function of the characteristics of power on shaft versus voltage for the analysis of power systems, aiming a load flow study. Thereafter, a model of an equivalent motor which has a basis the typical performance curve of an induction motor is present. This model is obtained from empirical parameters, surveyed from a population of over 1000 motors. (author) 3 refs., 1 fig., 4 tabs.

  5. Calculation of Wind Power Limit adjusting the Continuation Power Flow

    International Nuclear Information System (INIS)

    Santos Fuentefria, Ariel; Castro Fernández, Miguel; Martínez García, Antonio

    2012-01-01

    The wind power insertion in the power system is an important issue and can create some instability problems in voltage and system frequency due to stochastic origin of wind. Know the Wind Power Limit is a very important matter. Existing in bibliography a few methods for calculation of wind power limit. The calculation is based in static constrains, dynamic constraints or both. In this paper is developed a method for the calculation of wind power limit using some adjust in the continuation power flow, and having into account the static constrains. The method is complemented with Minimal Power Production Criterion. The method is proved in the Isla de la Juventud Electric System. The software used in the simulations was the Power System Analysis Toolbox (PSAT). (author)

  6. Future technological and economic performance of IGCC and FT production facilities with and without CO2 capture: Combining component based learning curve and bottom-up analysis

    NARCIS (Netherlands)

    Knoope, M.M.J.; Meerman, J.C.; Ramirez, C.A.; Faaij, A.P.C.

    2013-01-01

    This study aims to investigate the technological and economic prospects of integrated gasification facilities for power (IGCC) and Fischer–Tropsch (FT) liquid production with and without CCS over time. For this purpose, a component based experience curve was constructed and applied to identify the

  7. Modular load flow for restructured power systems

    CERN Document Server

    Hariharan, M V; Gupta, Pragati P

    2016-01-01

    In the subject of power systems, authors felt that a re-look is necessary at some conventional methods of analysis. In this book, the authors have subjected the time-honoured load flow to a close scrutiny. Authors have discovered and discussed a new load flow procedure – Modular Load Flow. Modular Load Flow explores use of power – a scalar – as source for electrical circuits which are conventionally analysed by means of phasors – the ac voltages or currents. The method embeds Kirchhoff’s circuit laws as topological property into its scalar equations and results in a unique wonderland where phase angles do not exist! Generators are shown to have their own worlds which can be superimposed to obtain the state of the composite power system. The treatment is useful in restructured power systems where stakeholders and the system operators may desire to know individual generator contributions in line flows and line losses for commercial reasons. Solution in Modular Load Flow consists of explicit expression...

  8. Transmission tariffs based on optimal power flow

    International Nuclear Information System (INIS)

    Wangensteen, Ivar; Gjelsvik, Anders

    1998-01-01

    This report discusses transmission pricing as a means of obtaining optimal scheduling and dispatch in a power system. This optimality includes consumption as well as generation. The report concentrates on how prices can be used as signals towards operational decisions of market participants (generators, consumers). The main focus is on deregulated systems with open access to the network. The optimal power flow theory, with demand side modelling included, is briefly reviewed. It turns out that the marginal costs obtained from the optimal power flow gives the optimal transmission tariff for the particular load flow in case. There is also a correspondence between losses and optimal prices. Emphasis is on simple examples that demonstrate the connection between optimal power flow results and tariffs. Various cases, such as open access and single owner are discussed. A key result is that the location of the ''marketplace'' in the open access case does not influence the net economical result for any of the parties involved (generators, network owner, consumer). The optimal power flow is instantaneous, and in its standard form cannot deal with energy constrained systems that are coupled in time, such as hydropower systems with reservoirs. A simplified example of how the theory can be extended to such a system is discussed. An example of the influence of security constraints on prices is also given. 4 refs., 24 figs., 7 tabs

  9. Performance analysis of a gas turbine for power generation using syngas as a fuel

    International Nuclear Information System (INIS)

    Lee, Jong Jun; Cha Kyu Sang; Kim, Tong Seop; Sohn, Jeong Lak; Joo, Yong Jin

    2008-01-01

    Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increase the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition

  10. More Energy-Efficient CO2 Capture from IGCC GE Flue Gases

    Directory of Open Access Journals (Sweden)

    Rakpong Peampermpool

    2017-03-01

    Full Text Available Carbon dioxide (CO2 emissions are one of the main reasons for the increase in greenhouse gasses in the earth’s atmosphere and carbon capture and sequestration (CCS is known as an effective method to reduce CO2 emissions on a larger scale, such as for fossil energy utilization systems. In this paper, the feasibility of capturing CO2 using cryogenic liquefaction and improving the capture rate by expansion will be discussed. The main aim was to design an energy-saving scheme for an IGCC (integrated gasification combined cycle power plant with CO2 cryogenic liquefaction capture. The experimental results provided by the authors, using the feed gas specification of a 740 MW IGCC General Electric (GE combustion power plant, demonstrated that using an orifice for further expanding the vent gas after cryogenic capture from 57 bar to 24 bar gave an experimentally observed capture rate up to 65%. The energy-saving scheme can improve the overall CO2 capture rate, and hence save energy. The capture process has also been simulated using Aspen HYSYS simulation software to evaluate its energy penalty. The results show that a 92% overall capture rate can be achieved by using an orifice.

  11. Power generation plants with carbon capture and storage: A techno-economic comparison between coal combustion and gasification technologies

    International Nuclear Information System (INIS)

    Tola, Vittorio; Pettinau, Alberto

    2014-01-01

    Highlights: • Techno-economic performance of coal-fired power plants (without and with CCS). • Without CCS system, USC is more efficient and cost-competitive than IGCC. • CCS energy penalties are more relevant for USC than IGCC. • Higher SNOX system costs are partially compensated by better USC performance. • CCS technologies cannot be profitable without adequate policies and incentives. - Abstract: Worldwide energy production requirements could not be fully satisfied by nuclear and renewables sources. Therefore a sustainable use of fossil fuels (coal in particular) will be required for several decades. In this scenario, carbon capture and storage (CCS) represents a key solution to control the global warming reducing carbon dioxide emissions. The integration between CCS technologies and power generation plants currently needs a demonstration at commercial scale to reduce both technological risks and high capital and operating cost. This paper compares, from the technical and economic points of view, the performance of three coal-fired power generation technologies: (i) ultra-supercritical (USC) plant equipped with a conventional flue gas treatment (CGT) process, (ii) USC plant equipped with SNOX technology for a combined removal of sulphur and nitrogen oxides and (iii) integrated gasification combined cycle (IGCC) plant based on a slurry-feed entrained-flow gasifier. Each technology was analysed in its configurations without and with CO 2 capture, referring to a commercial-scale of 1000 MW th . Technical assessment was carried out by using simulation models implemented through Aspen Plus and Gate-Cycle tools, whereas economic assessment was performed through a properly developed simulation model. USC equipped with CGT systems shows an overall efficiency (43.7%) comparable to IGCC (43.9%), whereas introduction of SNOX technology increases USC efficiency up to 44.8%. Being the CCS energy penalties significantly higher for USC (about 10.5% points vs. about 8

  12. Reusing balanced power flow object components for developing harmonic power flow

    Energy Technology Data Exchange (ETDEWEB)

    Nadarajah, S. [Peninsular Malaysia Electric Utility Co., Kuala Lumpur (Malaysia). Tenaga Nasional Berhad; Nor, K.M.; Abdel-Akher, M. [Malaysia Univ., Kuala Lumpur (Malaysia). Dept. of Electrical Engineering

    2005-07-01

    Harmonic power flows are used to examine the effects of nonlinear loads on power systems. In this paper, component technology was re-used for the development of a harmonic power flow. The object-oriented power system model (OO-PSM) was developed separately from a solution algorithm. Nodes, lines, and transformers were modelled as entity objects by classes. Power flow solution algorithms were modelled as control objects and encapsulated inside independent software components within the power system component software architecture (PS-COM). Both the OO-PSM and the PS-COM of the balanced power flow were re-used for developing the proposed harmonic power flow. A no-interaction hypothesis was used to consider both fundamental voltages and nonlinear device data dependence. A direct solution voltage node method was also used. The accuracy of the method was demonstrated using IEEE 14 bus and 30 bus test systems. It was concluded that component technology can be used to develop harmonic power flow programs. 7 refs., 2 tabs., 9 figs.

  13. Power Flow and Structure-Borne Noise

    DEFF Research Database (Denmark)

    Wachulec, Marcin

    The method of power flow analysis within a structure depends on the frequency considered. For the low frequencies the standard Finite Element Method (FEM) can be used efficiently. In the high frequencies the Statistical Energy Analysis (SEA) proved its usefulness. The distinction between low and ...

  14. A single IGCC design for variable CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, L.F.; Griffiths, J.; Wainwright, J.M. [Chevron Texaco Worldwide Power and Gasification, Houston, TX (United States)

    2002-07-01

    Global warming and the production of greenhouse gases (GHG) have become an important issue in many countries around the world. While there has been a heightened sense of awareness that the combustion of fossil fuels produces the majority of the controllable carbon dioxide released to the atmosphere, there have been few substantive solutions that produce economically realistic solutions. Moreover, some fossil fuels, like coal, are viewed negatively due to their relatively high carbon content per Btu. Integrated Gasification Combined Cycle (IGCC) offers the option of a realistic, economically viable solution for reducing, by pre-combustion capture, significant amounts of CO{sub 2} while using existing commercially proven technologies. The novel IGCC flowscheme is designed so that the power plant can be built and operated without CO{sub 2} removal and later upgraded to low CO{sub 2} emissions at minimal additional cost. The novel flowscheme is based on commercially proven technology using processes that are in operation today. Overall performance and capital cost estimates are presented and two other possible applications of the novel flowscheme are discussed in this paper. 17 refs., 3 figs., 2 tabs.

  15. Flow-through shares for power development

    International Nuclear Information System (INIS)

    Howie, K.D.

    1999-01-01

    Financial advantages will occur to power producers in Ontario provided that they are innovative in raising capital needed to take advantage of opportunities offered by the Energy Competition Act of 1998. In the new electricity regime, the availability of long term non-recourse debt financing supported by long term power purchasing from Ontario Hydro will probably decrease. The issuance of flow-through shares is a form of financing that could by available to them for certain projects, and there is the probability that greater equity financing will be needed. These flow-through shares can give investors immediate tax savings, a potential favorable return on their equity investment, and a means of financing certain kinds of power projects

  16. Flow reversal power limit for the HFBR

    International Nuclear Information System (INIS)

    Cheng, L.Y.; Tichler, P.R.

    1997-01-01

    The High Flux Beam Reactor (HFBR) is a pressurized heavy water moderated and cooled research reactor that began operation at 40 MW. The reactor was subsequently upgraded to 60 MW and operated at that level for several years. The reactor undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Questions which were raised about the afterheat removal capability during the flow reversal transition led to a reactor shutdown and subsequent resumption of operation at a reduced power of 30 MW. An experimental and analytical program to address these questions is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW. Direct use of the experimental results and an understanding of the governing phenomenology supports this conclusion

  17. A decoupled power flow algorithm using particle swarm optimization technique

    International Nuclear Information System (INIS)

    Acharjee, P.; Goswami, S.K.

    2009-01-01

    A robust, nondivergent power flow method has been developed using the particle swarm optimization (PSO) technique. The decoupling properties between the power system quantities have been exploited in developing the power flow algorithm. The speed of the power flow algorithm has been improved using a simple perturbation technique. The basic power flow algorithm and the improvement scheme have been designed to retain the simplicity of the evolutionary approach. The power flow is rugged, can determine the critical loading conditions and also can handle the flexible alternating current transmission system (FACTS) devices efficiently. Test results on standard test systems show that the proposed method can find the solution when the standard power flows fail.

  18. Power flow control of intertied ac microgrids

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    Microgrids are small reliable grids formed by clustering distributed sources and loads together. They can, in principle, operate at different voltages and frequencies like 50, 60, 400 Hz or even dc. Tying them together or to the mains grid for energy sharing would therefore require the insertion...... of interlinking power converters. Active and reactive power flows of these converters should preferably be managed autonomously without demanding for fast communication links. A scheme that can fulfill the objectives is now proposed, which upon realised, will result in more robustly integrated microgrids...

  19. Anomalous Power Flow and ``Ghost'' Sources

    Science.gov (United States)

    Monzon, Cesar

    2008-08-01

    It is demonstrated that EM radiation from complex sources can result in real power in restricted regions of space flowing back towards the sources, thereby mimicking “ghost” sources. This counterintuitive mechanism of radiation does not rely on backward waves, as ordinary waves carry the power. Ways to harness the effect by making it directional are presented, together with selected applications, of which deception is a prime example due to the nature of the phenomenon. The concept can be applied to other areas, such as mechanics, acoustics, etc., and can be realized with available technology.

  20. Hybrid wind power balance control strategy using thermal power, hydro power and flow batteries

    OpenAIRE

    Gelažanskas, Linas; Baranauskas, Audrius; Gamage, Kelum A.A.; Ažubalis, Mindaugas

    2016-01-01

    The increased number of renewable power plants pose threat to power system balance. Their intermittent nature makes it very difficult to predict power output, thus either additional reserve power plants or new storage and control technologies are required. Traditional spinning reserve cannot fully compensate sudden changes in renewable energy power generation. Using new storage technologies such as flow batteries, it is feasible to balance the variations in power and voltage within very short...

  1. Wheeling rates evaluation using optimal power flows

    International Nuclear Information System (INIS)

    Muchayi, M.; El-Hawary, M. E.

    1998-01-01

    Wheeling is the transmission of electrical power and reactive power from a seller to a buyer through a transmission network owned by a third party. The wheeling rates are then the prices charged by the third party for the use of its network. This paper proposes and evaluates a strategy for pricing wheeling power using a pricing algorithm that in addition to the fuel cost for generation incorporates the optimal allocation of the transmission system operating cost, based on time-of-use pricing. The algorithm is implemented for the IEEE standard 14 and 30 bus system which involves solving a modified optimal power flow problem iteratively. The base of the proposed algorithm is the hourly spot price. The analysis spans a total time period of 24 hours. Unlike other algorithms that use DC models, the proposed model captures wheeling rates of both real and reactive power. Based on the evaluation, it was concluded that the model has the potential for wide application in calculating wheeling rates in a deregulated competitive power transmission environment. 9 refs., 3 tabs

  2. Speciation of major and selected trace elements in IGCC fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Oriol Font; Xavier Querol; Frank E. Huggins; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

    2005-08-01

    The speciation of Ga, Ge, Ni, V, S and Fe in fly ash from IGCC power plant were investigated for possible further extraction process by combining conventional mineral and chemical analysis, leaching tests, wet sequential extraction, Moessbauer and XAFS spectroscopies. The results shown that Ge occurs mainly as water-soluble species, GeS and/or GeS{sub 2} and hexagonal GeO{sub 2}. Ga is present as an oxide, Ni occurs mainly as nickeline (NiAs), with minor proportions of Ni arsenates and vanadium as V(III) with minor amounts of V(IV) in the aluminosilicate glass matrix. Pyrrhotite and wurtzite-sphalerite are sulfide species containing Fe and Zn, but an important fraction of iron is also present in the aluminosilicate glass. These clear differences between the speciation of the above elements in this material and those reported for fly ash from conventional PC combustion. 15 refs., 8 figs., 5 tabs.

  3. Comparison of Shell, Texaco, BGL and KRW gasifiers as part of IGCC plant computer simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Furimsky, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2005-07-01

    The performances of four IGCC plants employing Shell, Texaco, BGL and KRW gasifiers were simulated using ASPEN Plus software for three different feeds. Performance analyses and comparisons of all four IGCC plants were performed based on the established data bank from the simulation. Discussions were focused on gas compositions, gasifier selection and overall performance.

  4. Developments in the pre-combustion CO2 capture pilot plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Damen, K.; Gnutek, R.; Kaptein, J.; Nannan, N.R.; Oyarzun, B.; Trapp, C.; Colonna, P.; Van Dijk, E.; Gross, J.; Bardow, A.

    2011-01-01

    N.V. Nuon (part of the Vattenfall Group) operates an IGCC in Buggenum and is developing a multi-fuel IGCC with CO2 capture and storage (Nuon Magnum) in Eemshaven, the Netherlands. In order to prepare for large-scale application of CO2 capture and storage, a CO2 capture pilot plant is constructed at

  5. MVA power flow and loss analysis for electricity market

    International Nuclear Information System (INIS)

    Wu, Z.Q.; Chen, G.Z.

    2001-01-01

    MVA power-flow and loss analysis is the basis for allocating the fixed costs and power losses under electricity-market deregulation. It is pointed out that the decomposition allocation of active and reactive power losses is not reasonable. The theory of active and reactive loss allocation and branch-power-flow decomposition has been proposed. Various contributory factors have been deduced. These contributory factors include the contribution factors of the active and reactive generation power, load-power-to-branch flows, the contribution factors of active and reactive generation power to active and reactive load power, the contribution factors of active and reactive load power to generation power, and the contribution factors of active and reactive load power and active and reactive generation power to line power losses. The detailed calculation results are presented and analysed, demonstrating that the theory presented provides a good charging algorithm for all the market participants. (Author)

  6. Pre-Combustion Capture of CO2 in IGCC Plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-12-15

    Pre-combustion capture involves reacting a fuel with oxygen or air and/or steam to give mainly a 'synthesis gas (syngas)' or 'fuel gas' composed of carbon monoxide and hydrogen. The carbon monoxide is reacted with steam in a catalytic reactor, called a shift converter, to produce CO2 and more hydrogen. CO2 is then separated, usually by a physical or chemical absorption process, resulting in a hydrogen-rich fuel which can be used in many applications, such as boilers, furnaces, gas turbines, engines and fuel cells. Pre-combustion capture is suitable for use in integrated gasification combined cycle (IGCC) plants especially since the CO2 partial pressures in the fuel gas are higher than in the flue gas. After the introduction there follows a short discussion of the water-gas shift (WGS) reaction. This is followed by chapters on the means of CO2 capture by physical and chemical solvents, solid sorbents, and membranes. The results and conclusions of techno-economic studies are introduced followed by a look at some of the pilot and demonstration plants relevant to pre-combustion capture in IGCC plants.

  7. Sludge pipe flow pressure drop prediction using composite power ...

    African Journals Online (AJOL)

    Sludge pipe flow pressure drop prediction using composite power-law friction ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue ... When predicting pressure gradients for the flow of sludges in pipes, the ...

  8. Operating modes and practical power flow analysis of bidirectional isolated power interface for distributed power systems

    International Nuclear Information System (INIS)

    Wen, Huiqing; Su, Bin

    2016-01-01

    Highlights: • Four operating modes of Dual-Phase-Shift control for Dual Active Bridge converter are presented. • Effects of “minor parameters” such as the deadtime and power device voltage drops are analyzed. • Accurate power flow models with Dual-Phase-Shift control are developed and verified with experimental results. • Optimal operating mode is determined with respect to the efficiency improvement. • Measured efficiency of the Dual Active Bridge converter is improved up to 14%. - Abstract: Due to the intermittent nature of the renewable energy sources including photovoltaic and wind energy, the energy storage systems are essential to stabilize dc bus voltage. Considering the discharge depth of super-capacitors and energy-storage batteries, the bidirectional isolated power interface will operate for a wide range of voltage and power. This study focuses on in-depth analysis of the dual-active-bridge dc–dc converter that is controlled by the dual-phase-shift scheme to improve the conversion efficiency in distributed power system. The power flow of each operating mode with dual-phase-shift control is characterized based on a detailed analysis of the effects of “minor parameters”, including the deadtime and power device voltage drops. The complete output power plane of the dual-active-bridge converter with dual-phase-shift control is obtained and compared with experimental results. The optimal operating mode is determined according to the practical output power range and the power flow characteristics. Experimental evaluation shows the effectiveness of the proposed power flow model with dual-phase-shift control and significant efficiency improvement using the optimal mode of dual-phase-shift compared with the conventional phase shift control.

  9. Topologically protected loop flows in high voltage AC power grids

    International Nuclear Information System (INIS)

    Coletta, T; Delabays, R; Jacquod, Ph; Adagideli, I

    2016-01-01

    Geographical features such as mountain ranges or big lakes and inland seas often result in large closed loops in high voltage AC power grids. Sizable circulating power flows have been recorded around such loops, which take up transmission line capacity and dissipate but do not deliver electric power. Power flows in high voltage AC transmission grids are dominantly governed by voltage angle differences between connected buses, much in the same way as Josephson currents depend on phase differences between tunnel-coupled superconductors. From this previously overlooked similarity we argue here that circulating power flows in AC power grids are analogous to supercurrents flowing in superconducting rings and in rings of Josephson junctions. We investigate how circulating power flows can be created and how they behave in the presence of ohmic dissipation. We show how changing operating conditions may generate them, how significantly more power is ohmically dissipated in their presence and how they are topologically protected, even in the presence of dissipation, so that they persist when operating conditions are returned to their original values. We identify three mechanisms for creating circulating power flows, (i) by loss of stability of the equilibrium state carrying no circulating loop flow, (ii) by tripping of a line traversing a large loop in the network and (iii) by reclosing a loop that tripped or was open earlier. Because voltages are uniquely defined, circulating power flows can take on only discrete values, much in the same way as circulation around vortices is quantized in superfluids. (paper)

  10. Probabilistic Power Flow Simulation allowing Temporary Current Overloading

    NARCIS (Netherlands)

    W.S. Wadman (Wander); G. Bloemhof; D.T. Crommelin (Daan); J.E. Frank (Jason)

    2012-01-01

    htmlabstractThis paper presents a probabilistic power flow model subject to connection temperature constraints. Renewable power generation is included and modelled stochastically in order to reflect its intermittent nature. In contrast to conventional models that enforce connection current

  11. Probablistic Power Flow Simulations Allowing Temporary Current Overloading

    NARCIS (Netherlands)

    Wadman, W.; Bloemhof, G.; Crommelin, D.; Frank, J.; Ozdemir, A.

    2013-01-01

    This paper presents a probabilistic power flow model subject to connection temperature constraints. Renewable power generation is included and modelled stochastically in order to reflect its intermittent nature. In contrast to conventional models that enforce connection current constraints,

  12. Routing power flows in distribution networks using locally controlled power electronics

    NARCIS (Netherlands)

    Hamelink, J.; Nguyen, P.H.; Kling, W.L.; Ribeiro, P.F.; Groot, de R.J.W.

    2012-01-01

    The power grid has gradually changed its operation during the recent decades. These developments have encouraged a shift from centralized to decentralized power flow control. A research has been carried out to investigate the possibilities to control power flows using the Smart Power Router (SPR) in

  13. Statistical Analysis of the Impact of Wind Power on Market Quantities and Power Flows

    DEFF Research Database (Denmark)

    Pinson, Pierre; Jónsson, Tryggvi; Zugno, Marco

    2012-01-01

    In view of the increasing penetration of wind power in a number of power systems and markets worldwide, we discuss some of the impacts that wind energy may have on market quantities and cross-border power flows. These impacts are uncovered through statistical analyses of actual market and flow data...... of load and wind power forecasts on Danish and German electricity markets....

  14. Power flow studies of magnetically insulated lines

    International Nuclear Information System (INIS)

    McDaniel, D.H.; Poukey, J.W.; Bergeron, K.D.; VanDevender, J.P.; Johnson, D.L.

    1977-01-01

    The designs for relativistic electron beam accelerators with power levels of 20 to 100 TW are greatly restricted by the inductance of a single diode of reasonable size. This fact leads to modular designs of very large accelerators. One concept uses several small insulators at a large radius arranged around the accelerator center. The total effective inductance is then low, but the energy must then be transported by self-magnetic insulated vacuum lines to the target volume. A triplate vacuum line configuration eases many mechanical support problems and allows more A-K gaps or feeds to be packaged around a given radius. This type of vacuum transmission line was chosen for initial experiments at Sandia. The experiments were conducted on the MITE (Magnetically Insulated Transmission Experiment) accelerator. The water pulse forming lines are connected to a vacuum triplate line through a conventional stacked insulator. Diagnostics on the experiment consisted of: (1) input V; (2) input I; (3) I monitors at the input, middle, and output of both the center conductor and ground plane of the transmission line; (4) magnetic energy analyzer to view peak electron energy in the A-K gap; (5) calorimetry; and (6) Faraday cups to look at electron current flowing across the transmission line. The main goal of the experiment is to obtain input impedance of the transmission line as a function of voltage and to measure electron loss currents. These measurements are compared to theoretical models for the input impedance and energy losses

  15. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    Directory of Open Access Journals (Sweden)

    Aouss Gabash

    2016-02-01

    Full Text Available It has recently been shown that using battery storage systems (BSSs to provide reactive power provision in a medium-voltage (MV active distribution network (ADN with embedded wind stations (WSs can lead to a huge amount of reverse power to an upstream transmission network (TN. However, unity power factors (PFs of WSs were assumed in those studies to analyze the potential of BSSs. Therefore, in this paper (Part-I, we aim to further explore the pure reactive power potential of WSs (i.e., without BSSs by investigating the issue of variable reverse power flow under different limits on PFs in an electricity market model. The main contributions of this work are summarized as follows: (1 Introducing the reactive power capability of WSs in the optimization model of the active-reactive optimal power flow (A-R-OPF and highlighting the benefits/impacts under different limits on PFs. (2 Investigating the impacts of different agreements for variable reverse power flow on the operation of an ADN under different demand scenarios. (3 Derivation of the function of reactive energy losses in the grid with an equivalent-π circuit and comparing its value with active energy losses. (4 Balancing the energy curtailment of wind generation, active-reactive energy losses in the grid and active-reactive energy import-export by a meter-based method. In Part-II, the potential of the developed model is studied through analyzing an electricity market model and a 41-bus network with different locations of WSs.

  16. Recycling of residual IGCC slags and their benefits as degreasers in ceramics.

    Science.gov (United States)

    Iglesias Martín, I; Acosta Echeverría, A; García-Romero, E

    2013-11-15

    This work studies the evolution of IGCC slag grains within a ceramic matrix fired at different temperatures to investigate the effect of using IGCC slag as a degreaser. Pressed ceramic specimens from two clay mixtures are used in this study. The M1 mixture is composed of standard clays, whereas the M2 mixture is composed of the same clay mixture as M1 mixture but contains 15% by weight IGCC slag. The amount of IGCC slag added coincides with the amount of slag typically used as a degreaser in the ceramic industry. Specimens are fired at 950 °C, 1000 °C, 1050 °C, 1100 °C and 1150 °C. The mineralogical composition and the IGCC slag grain shape within the ceramic matrix are determined by X-ray diffraction, polarized light microscopy and scanning electron microscopy. The results reveal that the surface of the slag grains is welded to the ceramic matrix while the quartz grains are separated, which causes increased water absorption and reduces the mechanical strength. IGCC slag, however, reduces water absorption. This behaviour is due to the softening temperature of the slag. This property is quite important from an industrial viewpoint because IGCC slag can serve as an alternative to traditional degreasing agents in the ceramic building industry. Additionally, using IGCC slag allows for the transformation of waste into a secondary raw material, thereby avoiding disposal at landfills; moreover, these industrial wastes are made inert and improve the properties of ceramics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  18. Comparisons of power transfer functions and flow transfer functions

    International Nuclear Information System (INIS)

    Grimm, K.N.; Meneghetti, D.

    1987-01-01

    Transfer functions may be used to calculate component feedbacks or temperature increments by convolution of the transfer function with the appropriate fractional change in system-quantity. Power-change transfer functions have been reported. The corresponding flow transfer functions for this case, and comparison with the power transfer functions, are reported here. Results of feedback simulation of ramped flow transients using flow transfer functions are also described

  19. AC power flow importance measures considering multi-element failures

    International Nuclear Information System (INIS)

    Li, Jian; Dueñas-Osorio, Leonardo; Chen, Changkun; Shi, Congling

    2017-01-01

    Quantifying the criticality of individual components of power systems is essential for overall reliability and management. This paper proposes an AC-based power flow element importance measure, while considering multi-element failures. The measure relies on a proposed AC-based cascading failure model, which captures branch overflow, bus load shedding, and branch failures, via AC power flow and optimal power flow analyses. Taking the IEEE 30, 57 and 118-bus power systems as case studies, we find that N-3 analyses are sufficient to measure the importance of a bus or branch. It is observed that for a substation bus, its importance is statistically proportional to its power demand, but this trend is not observed for power plant buses. While comparing with other reliability, functionality, and topology-based importance measures popular today, we find that a DC power flow model, although better correlated with the benchmark AC model as a whole, still fails to locate some critical elements. This is due to the focus of DC-based models on real power that ignores reactive power. The proposed importance measure is aimed to inform decision makers about key components in complex systems, while improving cascading failure prevention, system backup setting, and overall resilience. - Highlights: • We propose a novel importance measure based on joint failures and AC power flow. • A cascading failure model considers both AC power flow and optimal power flow. • We find that N-3 analyses are sufficient to measure the importance of an element. • Power demand impacts the importance of substations but less so that of generators. • DC models fail to identify some key elements, despite correlating with AC models.

  20. Geometry of power flows and convex-relaxed power flows in distribution networks with high penetration of renewables

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Zhao, Haoran

    2016-01-01

    Renewable energies are increasingly integrated in electric distribution networks and will cause severe overvoltage issues. Smart grid technologies make it possible to use coordinated control to mitigate the overvoltage issues and the optimal power flow (OPF) method is proven to be efficient...... in the applications such as curtailment management and reactive power control. Nonconvex nature of the OPF makes it difficult to solve and convex relaxation is a promising method to solve the OPF very efficiently. This paper investigates the geometry of the power flows and the convex-relaxed power flows when high...

  1. A congestion line flow control in deregulated power system

    Directory of Open Access Journals (Sweden)

    Venkatarajan Shanmuga Sundaram

    2011-01-01

    Full Text Available Under open access, market-driven transactions have become the new independent decision variables defining the behavior of the power system. The possibility of transmission lines getting over-loaded is relatively more under deregulated operation because different parts of the system are owned by separate companies and in part operated under varying service charges. This paper discusses a two-tier algorithm for correcting the lone overloads in conjunction with the conventional power-flow methods. The method uses line flow sensitivities, which are computed by the East Decoupled Power-flow algorithm and can be adapted for on-line implementation.

  2. Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in COAL IGCC Powerplants

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Yackly

    2004-09-30

    The ''Enabling & Information Technology To Increase RAM for Advanced Powerplants'' program, by DOE request, has been re-directed, de-scoped to two tasks, shortened to a 2-year period of performance, and refocused to develop, validate and accelerate the commercial use of enabling materials technologies and sensors for Coal IGCC powerplants. The new program has been re-titled as ''Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants'' to better match the new scope. This technical progress report summarizes the work accomplished in the reporting period April 1, 2004 to August 31, 2004 on the revised Re-Directed and De-Scoped program activity. The program Tasks are: Task 1--IGCC Environmental Impact on high Temperature Materials: This first materials task has been refocused to address Coal IGCC environmental impacts on high temperature materials use in gas turbines and remains in the program. This task will screen material performance and quantify the effects of high temperature erosion and corrosion of hot gas path materials in Coal IGCC applications. The materials of interest will include those in current service as well as advanced, high-performance alloys and coatings. Task 2--Material In-Service Health Monitoring: This second task develops and demonstrates new sensor technologies to determine the in-service health of advanced technology Coal IGCC powerplants, and remains in the program with a reduced scope. Its focus is now on only two critical sensor need areas for advanced Coal IGCC gas turbines: (1) Fuel Quality Sensor for detection of fuel impurities that could lead to rapid component degradation, and a Fuel Heating Value Sensor to rapidly determine the fuel heating value for more precise control of the gas turbine, and (2) Infra-Red Pyrometer to continuously measure the temperature of gas turbine buckets, nozzles, and combustor hardware.

  3. Probabilistic Power Flow Method Considering Continuous and Discrete Variables

    Directory of Open Access Journals (Sweden)

    Xuexia Zhang

    2017-04-01

    Full Text Available This paper proposes a probabilistic power flow (PPF method considering continuous and discrete variables (continuous and discrete power flow, CDPF for power systems. The proposed method—based on the cumulant method (CM and multiple deterministic power flow (MDPF calculations—can deal with continuous variables such as wind power generation (WPG and loads, and discrete variables such as fuel cell generation (FCG. In this paper, continuous variables follow a normal distribution (loads or a non-normal distribution (WPG, and discrete variables follow a binomial distribution (FCG. Through testing on IEEE 14-bus and IEEE 118-bus power systems, the proposed method (CDPF has better accuracy compared with the CM, and higher efficiency compared with the Monte Carlo simulation method (MCSM.

  4. Computing an operating parameter of a unified power flow controller

    Science.gov (United States)

    Wilson, David G.; Robinett, III, Rush D.

    2017-12-26

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  5. Computing an operating parameter of a unified power flow controller

    Science.gov (United States)

    Wilson, David G; Robinett, III, Rush D

    2015-01-06

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  6. Aerodynamics and Heat Transfer Studies of Parameters Specific to the IGCC-Requirements: Endwall Contouring, Leading Edge and Blade Tip Ejection under Rotating Turbine Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schobeiri, Meinhard; Han, Je-Chin

    2014-09-30

    This report deals with the specific aerodynamics and heat transfer problematic inherent to high pressure (HP) turbine sections of IGCC-gas turbines. Issues of primary relevance to a turbine stage operating in an IGCC-environment are: (1) decreasing the strength of the secondary flow vortices at the hub and tip regions to reduce (a), the secondary flow losses and (b), the potential for end wall deposition, erosion and corrosion due to secondary flow driven migration of gas flow particles to the hub and tip regions, (2) providing a robust film cooling technology at the hub and that sustains high cooling effectiveness less sensitive to deposition, (3) investigating the impact of blade tip geometry on film cooling effectiveness. The document includes numerical and experimental investigations of above issues. The experimental investigations were performed in the three-stage multi-purpose turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A&M University. For the numerical investigations a commercial Navier-Stokes solver was utilized.

  7. Novel simplified hourly energy flow models for photovoltaic power systems

    International Nuclear Information System (INIS)

    Khatib, Tamer; Elmenreich, Wilfried

    2014-01-01

    Highlights: • We developed an energy flow model for standalone PV system using MATLAB line code. • We developed an energy flow model for hybrid PV/wind system using MATLAB line code. • We developed an energy flow model for hybrid PV/diesel system using MATLAB line code. - Abstract: This paper presents simplified energy flow models for photovoltaic (PV) power systems using MATLAB. Three types of PV power system are taken into consideration namely standalone PV systems, hybrid PV/wind systems and hybrid PV/diesel systems. The logic of the energy flow for each PV power system is discussed first and then the MATLAB line codes for these models are provided and explained. The results prove the accuracy of the proposed models. Such models help modeling and sizing PV systems

  8. Hydrothermal optimal power flow using continuation method

    International Nuclear Information System (INIS)

    Raoofat, M.; Seifi, H.

    2001-01-01

    The problem of optimal economic operation of hydrothermal electric power systems is solved using powerful continuation method. While in conventional approach, fixed generation voltages are used to avoid convergence problems, in the algorithm, they are treated as variables so that better solutions can be obtained. The algorithm is tested for a typical 5-bus and 17-bus New Zealand networks. Its capabilities and promising results are assessed

  9. User-friendly Tool for Power Flow Analysis and Distributed ...

    African Journals Online (AJOL)

    Akorede

    AKOREDE et al: TOOL FOR POWER FLOW ANALYSIS AND DISTRIBUTED GENERATION OPTIMISATION. 23 ... greenhouse gas emissions and the current deregulation of electric energy ..... Visual composition and temporal behaviour of GUI.

  10. Security constrained optimal power flow by modern optimization tools

    African Journals Online (AJOL)

    Security constrained optimal power flow by modern optimization tools. ... International Journal of Engineering, Science and Technology ... If you would like more information about how to print, save, and work with PDFs, Highwire Press ...

  11. Security constrained optimal power flow by modern optimization tools

    African Journals Online (AJOL)

    The main objective of an optimal power flow (OPF) functions is to optimize .... It is characterized as propagation of plants and this happens by gametes union. ... ss and different variables, for example, wind, nearby fertilization can have a critic.

  12. Power of Your Pancreas: Keep Your Digestive Juices Flowing

    Science.gov (United States)

    ... 2017 Print this issue The Power of Your Pancreas Keep Your Digestive Juices Flowing En español Send ... in Check Better Check Your Bowels Wise Choices Pancreas Problems? Talk to your doctor if you have ...

  13. Process, background and design criteria of the gas cleaning at Puertollano IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Pisa, J. [Elcogas, Madrid (Spain)

    1998-11-01

    The Puertollano IGCC plant selected cooling by a water-tube boiler with upstream quenching at high velocities that requires a dust-free cooling gas at not less than 250{degree}C in order not to penalise the heat recovery efficiency. A filtration system for gas dedusting in the 250{degree}C temperature range has been installed and will be commissioned at the end of 1997. The gas cleaning concept is completed with a Venturi Scrubber, a COS hydrolysis reactor and a MDEA column to strip the sulphuric acid to yield clean gas. The gasification island is based upon the PRENFLO system which is an entrained-flow system with dry feeding. The selection of the filter system arrangement considered the limited operational experience in comparable operating conditions and acknowledged the flexibility of the filter system versus the cyclone-scrubber as far as easier load variation operation, the reduction of residues needing deposition and increased slag flow, as well as easier maintenance. Additionally to the ceramic test filters in Furstenhausen (PRENFLO) and Deer Park near Houston (SHELL), ceramic candle-type filter were selected in Buggenum and at Wabash River, and for the KoBra plant. The main criteria for the selection of the filter system and the type of candle were: separation efficiency to match clean gas limits; uniform distribution of the dust-laden gas to the filters; wear-resistant routing of the dust-laden gas flow; need for a supporting structure which must cope with sudden pressure fluctuations; optimised pulse gas system; and maintenance and repair. Based upon the above criteria, the PRENFLO concept requirements and the gas turbine specification, an arrangement with two pressure filter vessels with LLB design and filter elements manufactured by Schumacher has been installed in Puertollano. 2 figs., 3 tabs.

  14. Feasibility studies to improve plant availability and reduce total installed cost in IGCC plants

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Kevin [General Electric Company, Houston, TX (United States); Anasti, William [General Electric Company, Houston, TX (United States); Fang, Yichuan [General Electric Company, Houston, TX (United States); Subramanyan, Karthik [General Electric Company, Houston, TX (United States); Leininger, Tom [General Electric Company, Houston, TX (United States); Zemsky, Christine [General Electric Company, Houston, TX (United States)

    2015-03-30

    The main purpose of this project is to look at technologies and philosophies that would help reduce the costs of an Integrated Gasification Combined Cycle (IGCC) plant, increase its availability or do both. GE’s approach to this problem is to consider options in three different areas: 1) technology evaluations and development; 2) constructability approaches; and 3) design and operation methodologies. Five separate tasks were identified that fall under the three areas: Task 2 – Integrated Operations Philosophy; Task 3 – Slip Forming of IGCC Components; Task 4 – Modularization of IGCC Components; Task 5 – Fouling Removal; and Task 6 – Improved Slag Handling. Overall, this project produced results on many fronts. Some of the ideas could be utilized immediately by those seeking to build an IGCC plant in the near future. These include the considerations from the Integrated Operations Philosophy task and the different construction techniques of Slip Forming and Modularization (especially if the proposed site is in a remote location or has a lack of a skilled workforce). Other results include ideas for promising technologies that require further development and testing to realize their full potential and be available for commercial operation. In both areas GE considers this project to be a success in identifying areas outside the core IGCC plant systems that are ripe for cost reduction and ity improvement opportunities.

  15. Thermodynamic evaluation of CHP (combined heat and power) plants integrated with installations of coal gasification

    International Nuclear Information System (INIS)

    Ziębik, Andrzej; Malik, Tomasz; Liszka, Marcin

    2015-01-01

    Integration of a CHP steam plant with an installation of coal gasification and gas turbine leads to an IGCC-CHP (integrated gasification combined cycle-combined heat and power). Two installations of coal gasification have been analyzed, i.e. pressurized entrained flow gasifier – case 1 and pressurized fluidized bed gasifier with CO_2 recirculation – case 2. Basing on the results of mathematical modelling of an IGCC-CHP plant, the algorithms of calculating typical energy indices have been derived. The following energy indices are considered, i.e. coefficient of heat performance and relative savings of chemical energy of fuels. The results of coefficients of heat performance are contained between 1.87 and 2.37. Values exceeding 1 are thermodynamically justified because the idea of cogeneration of heat and electricity based on combining cycles of the heat engine and heat pump the efficiency of which exceeds 1. Higher values concerning waste heat replace more thermodynamically effective sources of heat in CHP plants. Relative savings of the chemical energy of fuels are similar in both cases of IGCC-CHP plants and are contained between the lower value of the CHP (combined heat and power) plants fuelled with coal and higher value of CHP plants fired with natural gas. - Highlights: • Energy savings of fuel is an adequate measure of cogeneration. • Relative energy savings of IGCC-CHP is near the result of a gas and steam CHP. • COHP (coefficient of heat performance) can help to divide fuel between heat fluxes. • Higher values of COHP in the case of waste heat recovery result from the lower thermal parameters.

  16. A Lyapunov theory based UPFC controller for power flow control

    Energy Technology Data Exchange (ETDEWEB)

    Zangeneh, Ali; Kazemi, Ahad; Hajatipour, Majid; Jadid, Shahram [Center of Excellence for Power Systems Automation and Operation, Iran University of Science and Technology, Tehran (Iran)

    2009-09-15

    Unified power flow controller (UPFC) is the most comprehensive multivariable device among the FACTS controllers. Capability of power flow control is the most important responsibility of UPFC. According to high importance of power flow control in transmission lines, the proper controller should be robust against uncertainty and disturbance and also have suitable settling time. For this purpose, a new controller is designed based on the Lyapunov theory and its stability is also evaluated. The Main goal of this paper is to design a controller which enables a power system to track reference signals precisely and to be robust in the presence of uncertainty of system parameters and disturbances. The performance of the proposed controller is simulated on a two bus test system and compared with a conventional PI controller. The simulation results show the power and accuracy of the proposed controller. (author)

  17. SELECTIVE MODAL ANALYSIS OF POWER FLOW OSCILLATION IN LARGE SCALE LONGITUDINAL POWER SYSTEMS

    Directory of Open Access Journals (Sweden)

    Wirindi -

    2009-06-01

    Full Text Available Novel selective modal analysis for the determination of low frequency power flow oscillation behaviour based on eigenvalues with corresponding damping ratio, cumulative damping index, and participation factors is proposed. The power system being investigated consists of three large longitudinally interconnected areas with some weak tie lines. Different modes, such as exciter modes, inter area modes, and local modes of the dominant poles are fully studied to find out the significant level of system damping and other factors producing power flow instability. The nature of the energy exchange between area is determined and strategic power flow stability improvement is developed and tested.

  18. Impact of Wind Power Generation on European Cross-Border Power Flows

    DEFF Research Database (Denmark)

    Zugno, Marco; Pinson, Pierre; Madsen, Henrik

    2013-01-01

    analysis is employed in order to reduce the problem dimension. Then, nonlinear relationships between forecast wind power production as well as spot price in Germany, by far the largest wind power producer in Europe, and power flows are modeled using local polynomial regression. We find that both forecast...... wind power production and spot price in Germany have substantial nonlinear effects on power transmission on a European scale.......A statistical analysis is performed in order to investigate the relationship between wind power production and cross-border power transmission in Europe. A dataset including physical hourly cross-border power exchanges between European countries as dependent variables is used. Principal component...

  19. Unified Power Flow Controller Placement to Improve Damping of Power Oscillations

    OpenAIRE

    M. Salehi; A. A. Motie Birjandi; F. Namdari

    2015-01-01

    Weak damping of low frequency oscillations is a frequent phenomenon in electrical power systems. These frequencies can be damped by power system stabilizers. Unified power flow controller (UPFC), as one of the most important FACTS devices, can be applied to increase the damping of power system oscillations and the more effect of this controller on increasing the damping of oscillations depends on its proper placement in power systems. In this paper, a technique based on controllability is pro...

  20. ac power control in the Core Flow Test Loop

    International Nuclear Information System (INIS)

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report

  1. On load flow control in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Herbig, Arnim

    2000-01-01

    This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this thesis, namely the controlled series capacitor (CSC), the phase angle regulator (PAR), and the unified power flow controller (UPFC). Properties and characteristics of these devices axe investigated and discussed. A simple control strategy is proposed. This strategy is then analyzed extensively. Mathematical methods and physical knowledge about the pertinent phenomena are combined, and it is shown that this control strategy can be used for a fairly general class of devices. Computer simulations of the controlled system provide insight into the system behavior in a system of reasonable size. The robustness and stability of the control system are discussed as are its limits. Further, the behavior of the control strategy in a system where the modeling allows for dynamic phenomena are investigated with computer simulations. It is discussed under which circumstances the control action has beneficial or detrimental effect on the system dynamics. Finally, a graphical approach for analyzing the effect of controllers

  2. Questionnaire regarding the international Freiberg conference on IGCC and XtL technologies. Analysis of 75 questionnaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The Puertollano IGCC Plant, owned by ELCOGAS, uses a mixture (50/50% weight) of local coal with high content of ash (approximately 45%) and pet-coke to be fed into its pressurised entrained flow gasifier. Ash is removed from the bottom of the gasifier as vitrified slag although a fraction is converted into fly ash (2.5-3 t/h) and entrained by the syngas. In order to remove this fly ash, it is filtered in two candle filter vessels with more than 1,000 candles each, using nitrogen for on-line cleaning. The filtering system suffers some malfunctions resulting in blinding of the internal candle surface and increasing of the candle DP. The model of candle filter was changed and modifications were performed without the desired results. Therefore, the identification of suitable hot gas filtration technologies capable of overcoming current and future severe operational constraints experienced is of the utmost importance for IGCC units. In this sense, a pilot plant which allows the performance of alternative filtering elements tests, pulse cleaning strategies, on-line particulate monitoring and off-cleaning procedures has come into operation at the ESI-University of Seville facilities. The design has been conceived as a versatile pilot unit, in order to hold both bags and ceramic candles which are to be tested in a wide range of operating conditions. The pilot is processing air laden with real fly ash provided by ELCOGAS, and high pressure nitrogen for the cleaning operation. This paper describes the design and operation of the pilot as well as the testing plan currently being carried out. (orig.)

  3. Research on stochastic power-flow study methods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Heydt, G. T. [ed.

    1981-01-01

    A general algorithm to determine the effects of uncertainty in bus load and generation on the output of conventional power flow analysis is presented. The use of statistical moments is presented and developed as a means for representing the stochastic process. Statistical moments are used to describe the uncertainties, and facilitate the calculations of single and multivarlate probability density functions of input and output variables. The transformation of the uncertainty through the power flow equations is made by the expansion of the node equations in a multivariate Taylor series about an expected operating point. The series is truncated after the second order terms. Since the power flow equations are nonlinear, the expected values of output quantities is in general not the solution to the conventional load flow problem using expected values of input quantities. The second order transformation offers a correction vector and allows the consideration of larger uncertainties which have caused significant error in the current linear transformation algorithms. Voltage controlled busses are included with consideration of upper and lower limits. The finite reactive power available at generation sites, and fixed ranges of transformer tap movement may have a significant effect on voltage and line power flow statistics. A method is given which considers limitation constraints in the evaluation of all output quantities. The bus voltages, line power flows, transformer taps, and generator reactive power requirements are described by their statistical moments. Their values are expressed in terms of the probability that they are above or below specified limits, and their expected values given that they do fall outside the limits. Thus the algorithm supplies information about severity of overload as well as probability of occurrence. An example is given for an eleven bus system, evaluating each quantity separately. The results are compared with Monte Carlo simulation.

  4. Pumping power of nanofluids in a flowing system

    International Nuclear Information System (INIS)

    Routbort, Jules L.; Singh, Dileep; Timofeeva, Elena V.; Yu, Wenhua; France, David M.

    2011-01-01

    Nanofluids have the potential to increase thermal conductivities and heat transfer coefficients compared to their base fluids. However, the addition of nanoparticles to a fluid also increases the viscosity and therefore increases the power required to pump the fluid through the system. When the benefit of the increased heat transfer is larger than the penalty of the increased pumping power, the nanofluid has the potential for commercial viability. The pumping power for nanofluids has been considered previously for flow in straight tubes. In this study, the pumping power was measured for nanofluids flowing in a complete system including straight tubing, elbows, and expansions. The objective was to determine the significance of two-phase flow effects on system performance. Two types of nanofluids were used in this study: a water-based nanofluid containing 2.0–8.0 vol% of 40-nm alumina nanoparticles, and a 50/50 ethylene glycol/water mixture-based nanofluid containing 2.2 vol% of 29-nm SiC nanoparticles. All experiments were performed in the turbulent flow region in the entire test system simulating features typically found in heat exchanger systems. Experimental results were compared to the pumping power calculated from a mathematical model of the system to evaluate the system effects. The pumping power results were also combined with the heat transfer enhancement to evaluate the viability of the two nanofluids.

  5. Method for controlling power flow between an electrochemical cell and a power grid

    International Nuclear Information System (INIS)

    Coleman, A. K.

    1981-01-01

    A method is disclosed for controlling a force-commutated inverter coupled between an electrochemical cell and a power grid for adjusting the magnitude and direction of the electrical energy flowing therebetween. Both the real power component and the reactive power component of ac electrical energy flow can be independently VARied through the switching waveform presented to the intermediately coupled inverter. A VAR error signal is derived from a comparison of a var command signal with a signal proportional to the actual reactive power circulating between the inverter and the power grid. This signal is presented to a voltage controller which essentially varies only the effective magnitude of the fundamental voltage waveform out of the inverter , thereby leaving the real power component substantially unaffected. In a similar manner, a power error signal is derived by a comparison of a power command signal with a signal proportional to the actual real power flowing between the electrochemical cell and the power grid. This signal is presented to a phase controller which varies only the phase of the fundamental component of the voltage waveform out of the inverter relative to that of the power grid and changes only the real power in proportion thereto, thus leaving the reactive power component substantially unaffected

  6. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  7. Dynamic ADMM for Real-time Optimal Power Flow: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-23

    This paper considers distribution networks featuring distributed energy resources (DERs), and develops a dynamic optimization method to maximize given operational objectives in real time while adhering to relevant network constraints. The design of the dynamic algorithm is based on suitable linearizations of the AC power flow equations, and it leverages the so-called alternating direction method of multipliers (ADMM). The steps of the ADMM, however, are suitably modified to accommodate appropriate measurements from the distribution network and the DERs. With the aid of these measurements, the resultant algorithm can enforce given operational constraints in spite of inaccuracies in the representation of the AC power flows, and it avoids ubiquitous metering to gather the state of non-controllable resources. Optimality and convergence of the propose algorithm are established in terms of tracking of the solution of a convex surrogate of the AC optimal power flow problem.

  8. Zinc Bromide Flow Battery Installation for Islanding and Backup Power

    Science.gov (United States)

    2017-08-09

    demonstrates the energy security and cost benefits of implementing a Zn/Br Flow Battery-based ESS at the Marine Corps Air Station (MCAS) located at...user will be realized through the system’s peak shaving mode. This benefit was also used to calculate the operational cost reductions when using the...EW-201242) Zinc Bromide Flow Battery Installation for Islanding and Backup Power August 2017 This document has been cleared for public release

  9. Energy and ancillary service dispatch through dynamic optimal power flow

    International Nuclear Information System (INIS)

    Costa, A.L.; Costa, A. Simoes

    2007-01-01

    This paper presents an approach based on dynamic optimal power flow (DOPF) to clear both energy and spinning reserve day-ahead markets. A competitive environment is assumed, where agents can offer active power for both demand supply and ancillary services. The DOPF jointly determines the optimal solutions for both energy dispatch and reserve allocation. A non-linear representation for the electrical network is employed, which is able to take transmission losses and power flow limits into account. An attractive feature of the proposed approach is that the final optimal solution will automatically meet physical constraints such as generating limits and ramp rate restrictions. In addition, the proposed framework allows the definition of multiple zones in the network for each time interval, in order to ensure a more adequate distribution of reserves throughout the power system. (author)

  10. Linear Power-Flow Models in Multiphase Distribution Networks: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Andrey; Dall' Anese, Emiliano

    2017-05-26

    This paper considers multiphase unbalanced distribution systems and develops approximate power-flow models where bus-voltages, line-currents, and powers at the point of common coupling are linearly related to the nodal net power injections. The linearization approach is grounded on a fixed-point interpretation of the AC power-flow equations, and it is applicable to distribution systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. The proposed linear models can facilitate the development of computationally-affordable optimization and control applications -- from advanced distribution management systems settings to online and distributed optimization routines. Performance of the proposed models is evaluated on different test feeders.

  11. Cash flow forecasting model for nuclear power projects

    International Nuclear Information System (INIS)

    Liu Wei; Guo Jilin

    2002-01-01

    Cash flow forecasting is very important for owners and contractors of nuclear power projects to arrange the capital and to decrease the capital cost. The factors related to contractor cash flow forecasting are analyzed and a cash flow forecasting model is presented which is suitable for both contractors and owners. The model is efficiently solved using a cost-schedule data integration scheme described. A program is developed based on the model and verified with real project data. The result indicates that the model is efficient and effective

  12. Uncertainty analysis of power monitoring transit time ultrasonic flow meters

    International Nuclear Information System (INIS)

    Orosz, A.; Miller, D. W.; Christensen, R. N.; Arndt, S.

    2006-01-01

    A general uncertainty analysis is applied to chordal, transit time ultrasonic flow meters that are used in nuclear power plant feedwater loops. This investigation focuses on relationships between the major parameters of the flow measurement. For this study, mass flow rate is divided into three components, profile factor, density, and a form of volumetric flow rate. All system parameters are used to calculate values for these three components. Uncertainty is analyzed using a perturbation method. Sensitivity coefficients for major system parameters are shown, and these coefficients are applicable to a range of ultrasonic flow meters used in similar applications. Also shown is the uncertainty to be expected for density along with its relationship to other system uncertainties. One other conclusion is that pipe diameter sensitivity coefficients may be a function of the calibration technique used. (authors)

  13. Application of the load flow and random flow models for the analysis of power transmission networks

    International Nuclear Information System (INIS)

    Zio, Enrico; Piccinelli, Roberta; Delfanti, Maurizio; Olivieri, Valeria; Pozzi, Mauro

    2012-01-01

    In this paper, the classical load flow model and the random flow model are considered for analyzing the performance of power transmission networks. The analysis concerns both the system performance and the importance of the different system elements; this latter is computed by power flow and random walk betweenness centrality measures. A network system from the literature is analyzed, representing a simple electrical power transmission network. The results obtained highlight the differences between the LF “global approach” to flow dispatch and the RF local approach of randomized node-to-node load transfer. Furthermore, computationally the LF model is less consuming than the RF model but problems of convergence may arise in the LF calculation.

  14. Tampa electric company - IGCC project. Quarterly report, January 1, 1996--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This quarterly report consists of materials presented at a recent review of the project. The project is an IGCC project being conducted by Tampa Electric Company. The report describes the status of the facility construction, components, operations staff training, and discusses aspects of the project which may impact the final scheduled completion.

  15. Degradation of TBC Systems in Environments Relevant to Advanced Gas Turbines for IGCC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gleeson, Brian [Univ. of Pittsburgh, PA (United States)

    2014-09-30

    Air plasma sprayed (APS) thermal barrier coatings (TBCs) are used to provide thermal insulation for the hottest components in gas turbines. Zirconia stabilized with 7wt% yttria (7YSZ) is the most common ceramic top coat used for turbine blades. The 7YSZ coating can be degraded from the buildup of fly-ash deposits created in the power-generation process. Fly ash from an integrated gasification combined cycle (IGCC) system can result from coal-based syngas. TBCs are also exposed to harsh gas environments containing CO2, SO2, and steam. Degradation from the combined effects of fly ash and harsh gas atmospheres has the potential to severely limit TBC lifetimes. The main objective of this study was to use lab-scale testing to systematically elucidate the interplay between prototypical deposit chemistries (i.e., ash and its constituents, K2SO4, and FeS) and environmental oxidants (i.e., O2, H2O and CO2) on the degradation behavior of advanced TBC systems. Several mechanisms of early TBC failure were identified, as were the specific fly-ash constituents responsible for degradation. The reactivity of MCrAlY bondcoats used in TBC systems was also investigated. The specific roles of oxide and sulfate components were assessed, together with the complex interplay between gas composition, deposit chemistry and alloy reactivity. Bondcoat composition design strategies to mitigate corrosion were established, particularly with regard to controlling phase constitution and the amount of reactive elements the bondcoat contains in order to achieve optimal corrosion resistance.

  16. Application of Newton's optimal power flow in voltage/reactive power control

    Energy Technology Data Exchange (ETDEWEB)

    Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

    1990-11-01

    This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

  17. APPLICATION OF MODIFIED POWER FLOW TRACING METHOD FOR REACTIVE POWER PRICING IN PRACTICAL UTILITY SYSTEM

    Directory of Open Access Journals (Sweden)

    M. SUSITHRA

    2017-01-01

    Full Text Available Competitive trend towards restructuring and unbundling of transmission services has resulted in the need to discover the impact of a particular generator to load. This paper initially presents the analysis of three different reactive power valuation methods namely, Modified Ybus , Virtual flow approach and modified power flow tracing to compute the reactive power output from a particular generator to particular load. Among these methods, the modified power flow electricity tracing method is identified as the best method to trace the reactive power contribution from various reactive power sources to loads, transmission line, etc. Also this proposed method breakdown the total reactive power loss in a transmission line into components to be allocated to individual loads. Secondly, based on this Method a novel allocation method for reactive power service for practical system is proposed. Hence, this method can be useful in providing additional insight into power system operation and can be used to modify existing tariffs of charging for reactive power transmission loss and reactive power transmission services. Simulation and comparison results are shown by taking WSCC 9 and IEEE 30 bus system as test system.

  18. Three-phase model and power-flow analysis of microgrids and virtual power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kamh, M.Z.; Iravani, R. [Toronto Univ., ON (Canada). Dept. of Electrical and Computer Engineering, Energy Systems Group

    2009-07-01

    A distributed energy resources (DER) unit can be a distributed generation unit, a distributed storage unit, or a hybrid of the two. It can be dispatchable, non-dispatchable or pseudo-dispatchable. A DER unit is connected to the hosting utility directly or via an electronic converter. A three-phase model and power-flow analysis of microgrids and virtual power plants was presented. The presentation discussed DER classification; microgrids and virtual power plants; motivations and goals; and a proposed DER model and power flow approach. Validation and results were also offered. The developed algorithm was implemented in the sequence-component frame using the MATLAB platform. Case studies were offered in order to verify the accuracy of the DER model and the power-flow program. It was concluded that the developed software accommodates different DER configurations and accurately reflects their control strategies. figs.

  19. Multi-objective optimal power flow with FACTS devices

    International Nuclear Information System (INIS)

    Basu, M.

    2011-01-01

    This paper presents multi-objective differential evolution to optimize cost of generation, emission and active power transmission loss of flexible ac transmission systems (FACTS) device-equipped power systems. In the proposed approach, optimal power flow problem is formulated as a multi-objective optimization problem. FACTS devices considered include thyristor controlled series capacitor (TCSC) and thyristor controlled phase shifter (TCPS). The proposed approach has been examined and tested on the modified IEEE 30-bus and 57-bus test systems. The results obtained from the proposed approach have been compared with those obtained from nondominated sorting genetic algorithm-II, strength pareto evolutionary algorithm 2 and pareto differential evolution.

  20. 76 FR 53436 - Free Flow Power Corporation; Northland Power Mississippi River LLC; Notice of Competing...

    Science.gov (United States)

    2011-08-26

    ... Mississippi River, near the town of Luling, in St. Charles Parish, Louisiana. The sole purpose of a.... 14091-000] Free Flow Power Corporation; Northland Power Mississippi River LLC; Notice of Competing... Mississippi River LLC (Northland) filed preliminary permit applications, pursuant to section 4(f) of the...

  1. 76 FR 53427 - Free Flow Power Corporation; Northland Power Mississippi River LLC; Notice of Competing...

    Science.gov (United States)

    2011-08-26

    ... Mississippi River, near the town of Killona, in St. Charles Parish, Louisiana. The sole purpose of a.... 14092-000] Free Flow Power Corporation; Northland Power Mississippi River LLC; Notice of Competing... Mississippi River LLC (Northland) filed preliminary permit applications, pursuant to section 4(f) of the...

  2. Modeling a Distributed Power Flow Controller with a PEM Fuel Cell for Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    J. Chakravorty

    2018-02-01

    Full Text Available Electrical power demand is increasing at a relatively fast rate over the last years. Because of this increasing demand the power system is becoming very complex. Both electric utilities and end users of electric power are becoming increasingly concerned about power quality. This paper presents a new concept of distributed power flow controller (DPFC, which has been implemented with a proton exchange membrane (PEM fuel cell. In this paper, a PEM fuel cell has been simulated in Simulink/MATLAB and then has been used in the proposed DPFC model. The new proposed DPFC model has been tested on a IEEE 30 bus system.

  3. Optimal power flow using the league championship algorithm: A case study of the Algerian power system

    International Nuclear Information System (INIS)

    Bouchekara, H.R.E.H.; Abido, M.A.; Chaib, A.E.; Mehasni, R.

    2014-01-01

    Highlights: • Optimal power flow. • Reducing electrical energy loss. • Saving electrical energy. • Optimal operation. - Abstract: A new efficient optimization method, called the League Championship Algorithm (LCA) is proposed in this paper for solving the optimal power flow problem. This method is inspired by the competition of sport teams in an artificial sport league for several weeks and over a number of seasons. The proposed method has been applied to the Algerian power system network for different objectives. Furthermore, in order to assess the effectiveness of the proposed LCA method the obtained results using this method have been compared to those obtained using other methods reported in the literature. The obtained results and the comparison with other techniques indicate that the league championship algorithm provides effective and high-quality solution when solving the optimal power flow problem

  4. Power flow prediction in vibrating systems via model reduction

    Science.gov (United States)

    Li, Xianhui

    This dissertation focuses on power flow prediction in vibrating systems. Reduced order models (ROMs) are built based on rational Krylov model reduction which preserve power flow information in the original systems over a specified frequency band. Stiffness and mass matrices of the ROMs are obtained by projecting the original system matrices onto the subspaces spanned by forced responses. A matrix-free algorithm is designed to construct ROMs directly from the power quantities at selected interpolation frequencies. Strategies for parallel implementation of the algorithm via message passing interface are proposed. The quality of ROMs is iteratively refined according to the error estimate based on residual norms. Band capacity is proposed to provide a priori estimate of the sizes of good quality ROMs. Frequency averaging is recast as ensemble averaging and Cauchy distribution is used to simplify the computation. Besides model reduction for deterministic systems, details of constructing ROMs for parametric and nonparametric random systems are also presented. Case studies have been conducted on testbeds from Harwell-Boeing collections. Input and coupling power flow are computed for the original systems and the ROMs. Good agreement is observed in all cases.

  5. Efficient relaxations for joint chance constrained AC optimal power flow

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Kyri; Toomey, Bridget

    2017-07-01

    Evolving power systems with increasing levels of stochasticity call for a need to solve optimal power flow problems with large quantities of random variables. Weather forecasts, electricity prices, and shifting load patterns introduce higher levels of uncertainty and can yield optimization problems that are difficult to solve in an efficient manner. Solution methods for single chance constraints in optimal power flow problems have been considered in the literature, ensuring single constraints are satisfied with a prescribed probability; however, joint chance constraints, ensuring multiple constraints are simultaneously satisfied, have predominantly been solved via scenario-based approaches or by utilizing Boole's inequality as an upper bound. In this paper, joint chance constraints are used to solve an AC optimal power flow problem while preventing overvoltages in distribution grids under high penetrations of photovoltaic systems. A tighter version of Boole's inequality is derived and used to provide a new upper bound on the joint chance constraint, and simulation results are shown demonstrating the benefit of the proposed upper bound. The new framework allows for a less conservative and more computationally efficient solution to considering joint chance constraints, specifically regarding preventing overvoltages.

  6. Modeling particle emission and power flow in pulsed-power driven, nonuniform transmission lines

    Directory of Open Access Journals (Sweden)

    Nichelle Bruner

    2008-04-01

    Full Text Available Pulsed-power driven x-ray radiographic systems are being developed to operate at higher power in an effort to increase source brightness and penetration power. Essential to the design of these systems is a thorough understanding of electron power flow in the transmission line that couples the pulsed-power driver to the load. In this paper, analytic theory and fully relativistic particle-in-cell simulations are used to model power flow in several experimental transmission-line geometries fielded on Sandia National Laboratories’ upgraded Radiographic Integrated Test Stand [IEEE Trans. Plasma Sci. 28, 1653 (2000ITPSBD0093-381310.1109/27.901250]. Good agreement with measured electrical currents is demonstrated on a shot-by-shot basis for simulations which include detailed models accounting for space-charge-limited electron emission, surface heating, and stimulated particle emission. Resonant cavity modes related to the transmission-line impedance transitions are also shown to be excited by electron power flow. These modes can drive oscillations in the output power of the system, degrading radiographic resolution.

  7. A Hybrid Harmony Search Algorithm Approach for Optimal Power Flow

    Directory of Open Access Journals (Sweden)

    Mimoun YOUNES

    2012-08-01

    Full Text Available Optimal Power Flow (OPF is one of the main functions of Power system operation. It determines the optimal settings of generating units, bus voltage, transformer tap and shunt elements in Power System with the objective of minimizing total production costs or losses while the system is operating within its security limits. The aim of this paper is to propose a novel methodology (BCGAs-HSA that solves OPF including both active and reactive power dispatch It is based on combining the binary-coded genetic algorithm (BCGAs and the harmony search algorithm (HSA to determine the optimal global solution. This method was tested on the modified IEEE 30 bus test system. The results obtained by this method are compared with those obtained with BCGAs or HSA separately. The results show that the BCGAs-HSA approach can converge to the optimum solution with accuracy compared to those reported recently in the literature.

  8. Hydro-thermal power flow scheduling accounting for head variations

    International Nuclear Information System (INIS)

    El-Hawary, M.E.; Ravindranath, K.M.

    1992-01-01

    In this paper the authors treat the problem of optimal economic operation of hydrothermal electric power systems with variable head hydro plants employing the power flow equations to represent the network. Newton's method is used to solve the problem for a number of test systems. A comparison with solutions with fixed head is presented. In general the optimal schedule requires higher slack bus and thermal power generation and cost in the case of variable head hydro plant than that required by the fixed head hydro plant in all demand periods. Correspondingly, the hydro generation is less in the case of variable head hydro plant compared to fixed head hydro plant. A negligible difference in voltage magnitudes in all the time intervals, but it is observed that slightly higher voltages occur in the case of the fixed head hydro plant. Higher power and energy losses occur in the case of variable head hydro plants compared to the fixed head hydro plants

  9. Modelling and Simulation of TCPAR for Power System Flow Studies

    Directory of Open Access Journals (Sweden)

    Narimen Lahaçani AOUZELLAG

    2012-12-01

    Full Text Available In this paper, the modelling of Thyristor Controlled Phase Angle Regulator ‘TCPAR’ for power flow studies and the role of that modelling in the study of Flexible Alternating Current Transmission Systems ‘FACTS’ for power flow control are discussed. In order to investigate the impact of TCPAR on power systems effectively, it is essential to formulate a correct and appropriate model for it. The TCPAR, thus, makes it possible to increase or decrease the power forwarded in the line where it is inserted in a considerable way, which makes of it an ideal tool for this kind of use. Knowing that the TCPAR does not inject any active power, it offers a good solution with a less consumption. One of the adverse effects of the TCPAR is the voltage drop which it causes in the network although it is not significant. To solve this disadvantage, it is enough to introduce a Static VAR Compensator ‘SVC’ into the electrical network which will compensate the voltages fall and will bring them back to an acceptable level.

  10. Optimal power flow management for distributed energy resources with batteries

    International Nuclear Information System (INIS)

    Tazvinga, Henerica; Zhu, Bing; Xia, Xiaohua

    2015-01-01

    Highlights: • A PV-diesel-battery hybrid system is proposed. • Model minimizes fuel and battery wear costs. • Power flows are analysed in a 24-h period. • Results provide a practical platform for decision making. - Abstract: This paper presents an optimal energy management model of a solar photovoltaic-diesel-battery hybrid power supply system for off-grid applications. The aim is to meet the load demand completely while satisfying the system constraints. The proposed model minimizes fuel and battery wear costs and finds the optimal power flow, taking into account photovoltaic power availability, battery bank state of charge and load power demand. The optimal solutions are compared for cases when the objectives are weighted equally and when a larger weight is assigned to battery wear. A considerable increase in system operational cost is observed in the latter case owing to the increased usage of the diesel generator. The results are important for decision makers, as they depict the optimal decisions considered in the presence of trade-offs between conflicting objectives

  11. Vortexlike Power Flow at the Interfaces of Metamaterial Lens

    Directory of Open Access Journals (Sweden)

    K. Fang

    2012-10-01

    Full Text Available The metamaterial lens with DPS/DNS/DPS structure has been realized by using the two-dimensional (2D isotropic transmission line approach. We studied the vortexlike power flow at the interfaces of metamaterial lens and validated by the finite-difference time-domain (FDTD simulator. The computational results showing its different conditions near DPS/DNS and other kinds of interfaces are obtained by CST STUDIO SUITE at different frequencies, and demonstrate the intuitionistic power location at the metamaterial lens interfaces.

  12. An Optimal Power Flow (OPF) Method with Improved Power System Stability

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2010-01-01

    This paper proposes an optimal power flow (OPF) method taking into account small signal stability as additional constraints. Particle swarm optimization (PSO) algorithm is adopted to realize the OPF process. The method is programmed in MATLAB and implemented to a nine-bus test power system which...... has large-scale wind power integration. The results show the ability of the proposed method to find optimal (or near-optimal) operating points in different cases. Based on these results, the analysis of the impacts of wind power integration on the system small signal stability has been conducted....

  13. Optimal Power Flow for Distribution Systems under Uncertain Forecasts: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano; Baker, Kyri; Summers, Tyler

    2016-12-01

    The paper focuses on distribution systems featuring renewable energy sources and energy storage devices, and develops an optimal power flow (OPF) approach to optimize the system operation in spite of forecasting errors. The proposed method builds on a chance-constrained multi-period AC OPF formulation, where probabilistic constraints are utilized to enforce voltage regulation with a prescribed probability. To enable a computationally affordable solution approach, a convex reformulation of the OPF task is obtained by resorting to i) pertinent linear approximations of the power flow equations, and ii) convex approximations of the chance constraints. Particularly, the approximate chance constraints provide conservative bounds that hold for arbitrary distributions of the forecasting errors. An adaptive optimization strategy is then obtained by embedding the proposed OPF task into a model predictive control framework.

  14. High pressure axial flow fans for modern coal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Cyrus, Vaclav [AHT Energetika s.r.o., Praha (Czech Republic); Koci, Petr [ZVVZ Milevsko a.s. (Czech Republic)

    2008-07-01

    Brown coal fired power stations, located in Northern Bohemia, have mostly older boiler blocks with an output of 110 and 200 MWe. Flue gases are cleaned by the desulphurization plants installed between 1993 and 1997. Usually, each boiler block has two air fans and one to three flue gas fans. Flue gas fans operate in severe conditions; fan blades should be resistant to the flue gases containing sulphur and acid drops with the operating temperature at 170 C to 190 C. Additionally, flue gas also often contains ash particles. Currently, some boiler blocks are gradually being refurbished. New blocks with an electrical power output of 600 to 700 MWe are at the design stage. Submitted paper shows our design study of one stage axial flow fan for the new blocks. Results from the new aerodynamic research of the axial flow stages were used in the fan design. (orig.)

  15. Oil-water flows in wells with powerful fracture reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, N.P.

    1979-01-01

    The character of two phase liquid flows from powerful layer fractures to bottom holes in Starogrodnen and Malgobek-Voznesenskiy fields in the Chechen-Ingush ASSR found in the late stage of operation. The studies were done with the electrothermometer TEG-36, the manometer MGN-2, the remote control thermal flow meter T-4, the remote control moisture meter VBST-1, the density meter GGP-1M, whose accuracy class is 1.0 and whose working limits are: temperature, up to 150/sup 0/C and pressure, up to 1000 kGs/cm/sup 2/. The breakdown of the linear filtration law and the gravitational division of the water-oil mixture phase occurred during fieldwork. The oil and water, etc., flow intervals were defined. The data from the moisture meter and the gamma density meter coincided.

  16. Load Flow Analysis of Hybrid AC-DC Power System with Offshore Wind Power

    DEFF Research Database (Denmark)

    Dhua, Debasish; Huang, Shaojun; Wu, Qiuwei

    2017-01-01

    The offshore wind power has received immense attention because of higher wind speed and lower opposition for construction. A wide range of combinations of high-voltage ACDC transmission have been proposed for integrating offshore wind farms and long-distance power transmission. This paper...... is to model such hybrid AC-DC systems including the interfacing converters, which have several control parameters that can change the load flow of the hybrid systems. Then, the paper proposes a Load Flow algorithm based on the Newton-Raphson method, which covers three different section types...

  17. Power system security enhancement with unified power flow controller under multi-event contingency conditions

    Directory of Open Access Journals (Sweden)

    S. Ravindra

    2017-03-01

    Full Text Available Power system security analysis plays key role in enhancing the system security and to avoid the system collapse condition. In this paper, a novel severity function is formulated using transmission line loadings and bus voltage magnitude deviations. The proposed severity function and generation fuel cost objectives are analyzed under transmission line(s and/or generator(s contingency conditions. The system security under contingency conditions is analyzed using optimal power flow problem. An improved teaching learning based optimization (ITLBO algorithm has been presented. To enhance the system security under contingency conditions in the presence of unified power flow controller (UPFC, it is necessary to identify an optimal location to install this device. Voltage source based power injection model of UPFC, incorporation procedure and optimal location identification strategy based on line overload sensitivity indexes are proposed. The entire proposed methodology is tested on standard IEEE-30 bus test system with supporting numerical and graphical results.

  18. IGCC and PFBC By-Products: Generation, Characteristics, and Management Practices

    Energy Technology Data Exchange (ETDEWEB)

    Pflughoeft-Hassett, D.F.

    1997-09-01

    The following report is a compilation of data on by-products/wastes from clean coal technologies, specifically integrated gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC). DOE had two objectives in providing this information to EPA: (1) to familiarize EPA with the DOE CCT program, CCT by-products, and the associated efforts by DOE contractors in the area of CCT by-product management and (2) to provide information that will facilitate EPA's effort by complementing similar reports from industry groups, including CIBO (Council of Industrial Boiler Owners) and EEI USWAG (Edison Electric Institute Utility Solid Waste Activities Group). The EERC cooperated and coordinated with DOE CCT contractors and industry groups to provide the most accurate and complete data on IGCC and PFBC by-products, although these technologies are only now being demonstrated on the commercial scale through the DOE CCT program.

  19. Partial analysis of wind power limit in an electric micro system using continuation power flow

    International Nuclear Information System (INIS)

    Fiallo Guerrero, Jandry; Santos Fuentefria, Ariel; Castro Fernández, Miguel

    2013-01-01

    The wind power insertion in the power system is an important issue and can create some instability problems in voltage and system frequency due to stochastic origin of wind. Know the Wind Power Limit that can insert in an electric grid without losing stability is a very important matter. Existing in bibliography a few methods for calculation of wind power limit, some of them are based in static constrains, an example is a method based in a continuation power flow analysis. In the present work the method is applied in an electric micro system formed when the system is disconnected of the man grid, the main goal was prove the method in a weak and island network. The software used in the simulations was the Power System Analysis Toolbox (PSAT). (author)

  20. Multilevel flow modeling of Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

    2011-01-01

    Multilevel Flow Modeling is a method for modeling complex processes on multiple levels of means-end and part-whole abstraction. The modeling method has been applied on a wide range of processes including power plants, chemical engineering plants and power systems. The modeling method is supported...... with reasoning tools for fault diagnosis and control and is proposed to be used as a central knowledge base giving integrated support in diagnosis and maintenance tasks. Recent developments of MFM include the introduction of concepts for representation of control functions and the relations between plant...... functions and structure. The paper will describe how MFM can be used to represent the goals and functions of the Japanese Monju Nuclear Power Plant. A detailed explanation will be given of the model describing the relations between levels of goal, function and structural. Furthermore, it will be explained...

  1. Fast wave power flow along SOL field lines in NSTX

    Science.gov (United States)

    Perkins, R. J.; Bell, R. E.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; Leblanc, B. P.; Kramer, G. J.; Phillips, C. K.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; Green, D. L.; McLean, A.; Maingi, R.; Ryan, P. M.; Jaeger, E. F.; Sabbagh, S.

    2012-10-01

    On NSTX, a major loss of high-harmonic fast wave (HHFW) power can occur along open field lines passing in front of the antenna over the width of the scrape-off layer (SOL). Up to 60% of the RF power can be lost and at least partially deposited in bright spirals on the divertor floor and ceiling [1,2]. The flow of HHFW power from the antenna region to the divertor is mostly aligned along the SOL magnetic field [3], which explains the pattern of heat deposition as measured with infrared (IR) cameras. By tracing field lines from the divertor back to the midplane, the IR data can be used to estimate the profile of HHFW power coupled to SOL field lines. We hypothesize that surface waves are being excited in the SOL, and these results should benchmark advanced simulations of the RF power deposition in the SOL (e.g., [4]). Minimizing this loss is critical optimal high-power long-pulse ICRF heating on ITER while guarding against excessive divertor erosion.[4pt] [1] J.C. Hosea et al., AIP Conf Proceedings 1187 (2009) 105. [0pt] [2] G. Taylor et al., Phys. Plasmas 17 (2010) 056114. [0pt] [3] R.J. Perkins et al., to appear in Phys. Rev. Lett. [0pt] [4] D.L. Green et al., Phys. Rev. Lett. 107 (2011) 145001.

  2. Novel findings about management of gastric cancer: A summary from 10th IGCC

    OpenAIRE

    Penon, Danila; Cito, Letizia; Giordano, Antonio

    2014-01-01

    The Tenth International Gastric Cancer Congress (IGCC) was held in Verona, Italy, from June 19 to 22, 2013. The meeting enclosed various aspects of stomach tumor management, including both tightly clinical approaches, and topics more related to basic research. Moreover, an overview on gastrointestinal stromal tumors was provided too, although here not discussed. Here we will discuss some topics related to molecular biology of gastric cancer (GC), inherent to prognostic, diagnostic and therape...

  3. Convective flow reversal in self-powered enzyme micropumps.

    Science.gov (United States)

    Ortiz-Rivera, Isamar; Shum, Henry; Agrawal, Arjun; Sen, Ayusman; Balazs, Anna C

    2016-03-08

    Surface-bound enzymes can act as pumps that drive large-scale fluid flows in the presence of their substrates or promoters. Thus, enzymatic catalysis can be harnessed for “on demand” pumping in nano- and microfluidic devices powered by an intrinsic energy source. The mechanisms controlling the pumping have not, however, been completely elucidated. Herein, we combine theory and experiments to demonstrate a previously unreported spatiotemporal variation in pumping behavior in urease-based pumps and uncover the mechanisms behind these dynamics. We developed a theoretical model for the transduction of chemical energy into mechanical fluid flow in these systems, capturing buoyancy effects due to the solution containing nonuniform concentrations of substrate and product. We find that the qualitative features of the flow depend on the ratios of diffusivities δ=D(P)/D(S) and expansion coefficients β=β(P)/β(S) of the reaction substrate (S) and product (P). If δ>1 and δ>β (or if δself-powered fluidic devices.

  4. An Integrated Design approach to Power Systems: from Power Flows to Electricity Markets

    Science.gov (United States)

    Bose, Subhonmesh

    Power system is at the brink of change. Engineering needs, economic forces and environmental factors are the main drivers of this change. The vision is to build a smart electrical grid and a smarter market mechanism around it to fulfill mandates on clean energy. Looking at engineering and economic issues in isolation is no longer an option today; it needs an integrated design approach. In this thesis, I shall revisit some of the classical questions on the engineering operation of power systems that deals with the nonconvexity of power flow equations. Then I shall explore some issues of the interaction of these power flow equations on the electricity markets to address the fundamental issue of market power in a deregulated market environment. Finally, motivated by the emergence of new storage technologies, I present an interesting result on the investment decision problem of placing storage over a power network. The goal of this study is to demonstrate that modern optimization and game theory can provide unique insights into this complex system. Some of the ideas carry over to applications beyond power systems.

  5. Flow Control in Wells Turbines for Harnessing Maximum Wave Power

    Science.gov (United States)

    Garrido, Aitor J.; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-01-01

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness. PMID:29439408

  6. Flow Control in Wells Turbines for Harnessing Maximum Wave Power.

    Science.gov (United States)

    Lekube, Jon; Garrido, Aitor J; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-02-10

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness.

  7. A virtual power plant model for time-driven power flow calculations

    Directory of Open Access Journals (Sweden)

    Gerardo Guerra

    2017-11-01

    Full Text Available This paper presents the implementation of a custom-made virtual power plant model in OpenDSS. The goal is to develop a model adequate for time-driven power flow calculations in distribution systems. The virtual power plant is modeled as the aggregation of renewable generation and energy storage connected to the distribution system through an inverter. The implemented operation mode allows the virtual power plant to act as a single dispatchable generation unit. The case studies presented in the paper demonstrate that the model behaves according to the specified control algorithm and show how it can be incorporated into the solution scheme of a general parallel genetic algorithm in order to obtain the optimal day-ahead dispatch. Simulation results exhibit a clear benefit from the deployment of a virtual power plant when compared to distributed generation based only on renewable intermittent generation.

  8. Convex relaxation of Optimal Power Flow in Distribution Feeders with embedded solar power

    DEFF Research Database (Denmark)

    Hermann, Alexander Niels August; Wu, Qiuwei; Huang, Shaojun

    2016-01-01

    There is an increasing interest in using Distributed Energy Resources (DER) directly coupled to end user distribution feeders. This poses an array of challenges because most of today’s distribution feeders are designed for unidirectional power flow. Therefore when installing DERs such as solar...... panels with uncontrolled inverters, the upper limit of installable capacity is quickly reached in many of today’s distribution feeders. This problem can often be mitigated by optimally controlling the voltage angles of inverters. However, the optimal power flow problem in its standard form is a large...... scale non-convex optimization problem, and thus can’t be solved precisely and also is computationally heavy and intractable for large systems. This paper examines the use of a convex relaxation using Semi-definite programming to optimally control solar power inverters in a distribution grid in order...

  9. PACTOLUS, Nuclear Power Plant Cost and Economics by Discounted Cash Flow Method. CLOTHO, Mass Flow Data Calculation for Program PACTOLUS

    International Nuclear Information System (INIS)

    Haffner, D.R.

    1976-01-01

    1 - Description of problem or function: PACTOLUS is a code for computing nuclear power costs using the discounted cash flow method. The cash flows are generated from input unit costs, time schedules and burnup data. CLOTHO calculates and communicates to PACTOLUS mass flow data to match a specified load factor history. 2 - Method of solution: Plant lifetime power costs are calculated using the discounted cash flow method. 3 - Restrictions on the complexity of the problem - Maxima of: 40 annual time periods into which all costs and mass flows are accumulated, 20 isotopic mass flows charged into and discharged from the reactor model

  10. Exergy analysis of an IGCC design configuration for Plant Wansley

    International Nuclear Information System (INIS)

    Tsatsaronis, G.; Tawfik, T.; Lin, L.; Gallaspy, D.T.

    1989-01-01

    An integrated gasification-combined-cycle power plant design was developed for Georgia Power Company's Plant Wansley. This paper discusses the plant configuration and presents the most important results obtained from a detailed exergy analysis of the plant design. This analysis will be completed in a subsequent paper through an exergoeconomic analysis to identify design improvements for reducing the electricity cost

  11. A fast method for optimal reactive power flow solution

    Energy Technology Data Exchange (ETDEWEB)

    Sadasivam, G; Khan, M A [Anna Univ., Madras (IN). Coll. of Engineering

    1990-01-01

    A fast successive linear programming (SLP) method for minimizing transmission losses and improving the voltage profile is proposed. The method uses the same compactly stored, factorized constant matrices in all the LP steps, both for power flow solution and for constructing the LP model. The inherent oscillatory convergence of SLP methods is overcome by proper selection of initial step sizes and their gradual reduction. Detailed studies on three systems, including a 109-bus system, reveal the fast and reliable convergence property of the method. (author).

  12. Reliability analysis of HVDC grid combined with power flow simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yongtao; Langeland, Tore; Solvik, Johan [DNV AS, Hoevik (Norway); Stewart, Emma [DNV KEMA, Camino Ramon, CA (United States)

    2012-07-01

    Based on a DC grid power flow solver and the proposed GEIR, we carried out reliability analysis for a HVDC grid test system proposed by CIGRE working group B4-58, where the failure statistics are collected from literature survey. The proposed methodology is used to evaluate the impact of converter configuration on the overall reliability performance of the HVDC grid, where the symmetrical monopole configuration is compared with the bipole with metallic return wire configuration. The results quantify the improvement on reliability by using the later alternative. (orig.)

  13. Heat Integration of the Water-Gas Shift Reaction System for Carbon Sequestration Ready IGCC Process with Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

    2010-01-01

    Integrated gasification combined cycle (IGCC) technology has been considered as an important alternative for efficient power systems that can reduce fuel consumption and CO2 emissions. One of the technological schemes combines water-gas shift reaction and chemical-looping combustion as post gasification techniques in order to produce sequestration-ready CO2 and potentially reduce the size of the gas turbine. However, these schemes have not been energetically integrated and process synthesis techniques can be applied to obtain an optimal flowsheet. This work studies the heat exchange network synthesis (HENS) for the water-gas shift reaction train employing a set of alternative designs provided by Aspen energy analyzer (AEA) and combined in a process superstructure that was simulated in Aspen Plus (AP). This approach allows a rigorous evaluation of the alternative designs and their combinations avoiding all the AEA simplifications (linearized models of heat exchangers). A CAPE-OPEN compliant capability which makes use of a MINLP algorithm for sequential modular simulators was employed to obtain a heat exchange network that provided a cost of energy that was 27% lower than the base case. Highly influential parameters for the pos gasification technologies (i.e. CO/steam ratio, gasifier temperature and pressure) were calculated to obtain the minimum cost of energy while chemical looping parameters (oxidation and reduction temperature) were ensured to be satisfied.

  14. AGC of a multi-area power system under deregulated environment using redox flow batteries and interline power flow controller

    Directory of Open Access Journals (Sweden)

    Tulasichandra Sekhar Gorripotu

    2015-12-01

    Full Text Available In this paper, Proportional Integral Derivative with Filter (PIDF is proposed for Automatic Generation Control (AGC of a multi-area power system in deregulated environment. Initially, a two area four units thermal system without any physical constraints is considered and the gains of the PIDF controller are optimized employing Differential Evolution (DE algorithm using ITAE criterion. The superiority of proposed DE optimized PIDF controller over Fuzzy Logic controller is demonstrated. Then, to further improve the system performance, an Interline Power Flow Controller (IPFC is placed in the tie-line and Redox Flow Batteries (RFB is considered in the first area and the controller parameters are tuned. Additionally, to get an accurate insight of the AGC problem, important physical constraints such as Time Delay (TD and Generation Rate Constraints (GRC are considered and the controller parameters are retuned. The performance of proposed controller is evaluated under different operating conditions that take place in a deregulated power market. Further, the proposed approach is extended to a two area six units hydro thermal system. Finally, sensitivity analysis is performed by varying the system parameters and operating load conditions from their nominal values.

  15. Curing critical links in oscillator networks as power flow models

    International Nuclear Information System (INIS)

    Rohden, Martin; Meyer-Ortmanns, Hildegard; Witthaut, Dirk; Timme, Marc

    2017-01-01

    Modern societies crucially depend on the robust supply with electric energy so that blackouts of power grids can have far reaching consequences. Typically, large scale blackouts take place after a cascade of failures: the failure of a single infrastructure component, such as a critical transmission line, results in several subsequent failures that spread across large parts of the network. Improving the robustness of a network to prevent such secondary failures is thus key for assuring a reliable power supply. In this article we analyze the nonlocal rerouting of power flows after transmission line failures for a simplified AC power grid model and compare different strategies to improve network robustness. We identify critical links in the grid and compute alternative pathways to quantify the grid’s redundant capacity and to find bottlenecks along the pathways. Different strategies are developed and tested to increase transmission capacities to restore stability with respect to transmission line failures. We show that local and nonlocal strategies typically perform alike: one can equally well cure critical links by providing backup capacities locally or by extending the capacities of bottleneck links at remote locations. (paper)

  16. Hydroelectric power plant with variable flow on drinking water adduction

    Science.gov (United States)

    Deaconu, S. I.; Babău, R.; Popa, G. N.; Gherman, P. L.

    2018-01-01

    The water feeding system of the urban and rural localities is mainly collected with feed pipes which can have different lengths and different levels. Before using, water must be treated. Since the treatment take place in the tanks, the pressure in the inlet of the station must be diminished. Many times the pressure must be reduced with 5-15 Barr and this is possible using valves, cavils, and so on. The flow capacity of the water consumption is highly fluctuating during one day, depending on the season, etc. This paper presents a method to use the hydroelectric potential of the feed pipes using a hydraulic turbine instead of the classical methods for decreasing the pressure. To avoid the dissipation of water and a good behavior of the power parameters it is used an asynchronous generator (AG) which is coupled at the electrical distribution network through a static frequency converter (SFC). The turbine has a simple structure without the classical devices (used to regulate the turbine blades). The speed of rotation is variable, depending on the necessary flow capacity in the outlet of the treatment station. The most important element of the automation is the static frequency converter (SFC) which allows speeds between 0 and 1.5 of the rated speed of rotation and the flow capacity varies accordingly with it.

  17. Considerations for transient stability, fault capacity and power flow study of offsite power system

    Energy Technology Data Exchange (ETDEWEB)

    Shin, M C; Kim, C W; Gwon, M H; Park, C W; Lee, K W; Kim, H M; Lee, G Y; Joe, P H [Sungkyunkwan Univ., Seoul (Korea, Republic of)

    1994-04-15

    By study of power flow calculation, fault capacity calculation and stability analysis according to connection of two units YGN 3 and 4 to KEPCO power system, we have conclusions as follows. As the result of power flow calculation, at peak load, the voltage change of each bus is very small when YGN 3 and 4 is connected with KEPCO power system. At base load, installation of phase modifing equipment is necessary in Seoul, Kyungki province where load is concentrated because bus voltage rises by increasing of charge capacity caused installation of underground cables. As the result of fault capacity calculation, fault capacity is increased because fault current increases when two units YGN 3 and 4 is connected with KEPCO power system. But it is enough to operate with presenting circuits breaker rated capacity. Transient stability studies have been conducted on the YK N/P generators 3 and 4 using a digital computer program. Three phase short faults have been simulated at the YK N/P 345[KV] bus with the resulting outage of transmission circuits. Several fault clearing times are applied: 6 cycles, 12 cycles, 15 cycles. The study results demonstrate that the transient stability of YK N/P is adequate to maintain stable for three phase short faults cleared within 12 cycles. The study results also demonstrate that the transient stability of YK N/P is stable for machine removals except 4-machine removal. In addition, the study shows that the transient stability analysis is implemented for the case of load.

  18. Ecosystem Services Flows: Why Stakeholders' Power Relationships Matter.

    Science.gov (United States)

    Felipe-Lucia, María R; Martín-López, Berta; Lavorel, Sandra; Berraquero-Díaz, Luis; Escalera-Reyes, Javier; Comín, Francisco A

    2015-01-01

    The ecosystem services framework has enabled the broader public to acknowledge the benefits nature provides to different stakeholders. However, not all stakeholders benefit equally from these services. Rather, power relationships are a key factor influencing the access of individuals or groups to ecosystem services. In this paper, we propose an adaptation of the "cascade" framework for ecosystem services to integrate the analysis of ecological interactions among ecosystem services and stakeholders' interactions, reflecting power relationships that mediate ecosystem services flows. We illustrate its application using the floodplain of the River Piedra (Spain) as a case study. First, we used structural equation modelling (SEM) to model the dependence relationships among ecosystem services. Second, we performed semi-structured interviews to identify formal power relationships among stakeholders. Third, we depicted ecosystem services according to stakeholders' ability to use, manage or impair ecosystem services in order to expose how power relationships mediate access to ecosystem services. Our results revealed that the strongest power was held by those stakeholders who managed (although did not use) those keystone ecosystem properties and services that determine the provision of other services (i.e., intermediate regulating and final services). In contrast, non-empowered stakeholders were only able to access the remaining non-excludable and non-rival ecosystem services (i.e., some of the cultural services, freshwater supply, water quality, and biological control). In addition, land stewardship, access rights, and governance appeared as critical factors determining the status of ecosystem services. Finally, we stress the need to analyse the role of stakeholders and their relationships to foster equal access to ecosystem services.

  19. Ecosystem Services Flows: Why Stakeholders’ Power Relationships Matter

    Science.gov (United States)

    Felipe-Lucia, María R.; Martín-López, Berta; Lavorel, Sandra; Berraquero-Díaz, Luis; Escalera-Reyes, Javier; Comín, Francisco A.

    2015-01-01

    The ecosystem services framework has enabled the broader public to acknowledge the benefits nature provides to different stakeholders. However, not all stakeholders benefit equally from these services. Rather, power relationships are a key factor influencing the access of individuals or groups to ecosystem services. In this paper, we propose an adaptation of the “cascade” framework for ecosystem services to integrate the analysis of ecological interactions among ecosystem services and stakeholders’ interactions, reflecting power relationships that mediate ecosystem services flows. We illustrate its application using the floodplain of the River Piedra (Spain) as a case study. First, we used structural equation modelling (SEM) to model the dependence relationships among ecosystem services. Second, we performed semi-structured interviews to identify formal power relationships among stakeholders. Third, we depicted ecosystem services according to stakeholders’ ability to use, manage or impair ecosystem services in order to expose how power relationships mediate access to ecosystem services. Our results revealed that the strongest power was held by those stakeholders who managed (although did not use) those keystone ecosystem properties and services that determine the provision of other services (i.e., intermediate regulating and final services). In contrast, non-empowered stakeholders were only able to access the remaining non-excludable and non-rival ecosystem services (i.e., some of the cultural services, freshwater supply, water quality, and biological control). In addition, land stewardship, access rights, and governance appeared as critical factors determining the status of ecosystem services. Finally, we stress the need to analyse the role of stakeholders and their relationships to foster equal access to ecosystem services. PMID:26201000

  20. Flow-accelerated corrosion in power plants. Revision 1

    International Nuclear Information System (INIS)

    Chexal, B.; Horowitz, J.; Dooley, B.

    1998-07-01

    Flow-Accelerated Corrosion (FAC) is a phenomenon that results in metal loss from piping, vessels, and equipment made of carbon steel. FAC occurs only under certain conditions of flow, chemistry, geometry, and material. Unfortunately, those conditions are common in much of the high-energy piping in nuclear and fossil-fueled power plants. Undetected, FAC will cause leaks and ruptures. Consequently, FAC has become a major issue, particularly for nuclear plants. Although major failures are rare, the consequences can be severe. In 1986, four men in the area of an FAC-induced pipe rupture were killed. Fossil plants too, are subject to FAC. In 1995, a failure at a fossil-fired plant caused two fatalities. In addition to concerns about personnel safety, FAC failures can pose challenges to plant safety. Regulatory agencies have therefore required nuclear utilities to institute formal programs to address FAC. Finally, a major FAC failure (like the one that happened in 1997 at a US nuclear power plant) can force a plant to shutdown and purchase replacement power at a price approaching a million dollars per day depending upon the MWe rating of the plant. A great deal of time and money has been spent to develop the technology to predict, detect, and mitigate FAC in order to prevent catastrophic failures. Over time, substantial progress has been made towards understanding and preventing FAC. The results of these efforts include dozens of papers, reports, calculations, and manuals, as well as computer programs and other tools. This book is written to provide a detailed treatment of the entire subject in a single document. Any complex issue requires balancing know-how, the risk of decision making, and a pragmatic engineering solution. This book addresses these by carrying out the necessary R and D and engineering along with plant knowledge to cover all quadrants of Chexal's four quadrant known-unknown diagram, as seen in Figure i

  1. Stand-alone excitation synchronous wind power generators with power flow management strategy

    Directory of Open Access Journals (Sweden)

    Tzuen-Lih Chern

    2014-09-01

    Full Text Available This study presents a stand-alone excitation synchronous wind power generator (SESWPG with power flow management strategy (PFMS. The rotor speed of the excitation synchronous generator tracks the utility grid frequency by using servo motor tracking technologies. The automatic voltage regulator governs the exciting current of generator to achieve the control goals of stable voltage. When wind power is less than the needs of the consumptive loading, the proposed PFMS increases motor torque to provide a positive power output for the loads, while keeping the generator speed constant. Conversely, during the periods of wind power greater than output loads, the redundant power of generator production is charged to the battery pack and the motor speed remains constant with very low power consumption. The advantage of the proposed SESWPG is that the generator can directly output stable alternating current (AC electricity without using additional DC–AC converters. The operation principles with software simulation for the system are described in detail. Experimental results of a laboratory prototype are shown to verify the feasibility of the system.

  2. Contingency management of power system with Interline Power Flow Controller using Real Power Performance Index and Line Stability Index

    Directory of Open Access Journals (Sweden)

    Akanksha Mishra

    2016-03-01

    Full Text Available As a result of privatization of the electrical industry the power transmission lines have to transfer power at their maximum transmission limits because of the competitive scenario of the electrical market. Hence, secured operation of power system has become one of the most important issues of modern era. In this paper, a probability of severity based placement strategy for Interline Power Flow Controller (IPFC has been proposed based on Composite Severity Index (CSI. The composite severity index provides an exact measure of stress in the line in terms of mega watt overloading and voltage instability. IPFC is placed on the line which has the highest probability of severity during the occurrence of different outages. The IPFC has been tuned for a multi-objective function using Differential Evolution (DE and the results have been compared with genetic Algorithm (GA. To verify the proposed method, it has been tested and implemented on IEEE 14 and 57 bus systems.

  3. Advanced modeling and simulation of integrated gasification combined cycle power plants with CO2-capture

    International Nuclear Information System (INIS)

    Rieger, Mathias

    2014-01-01

    The objective of this thesis is to provide an extensive description of the correlations in some of the most crucial sub-processes for hard coal fired IGCC with carbon capture (CC-IGCC). For this purpose, process simulation models are developed for four industrial gasification processes, the CO-shift cycle, the acid gas removal unit, the sulfur recovery process, the gas turbine, the water-/steam cycle and the air separation unit (ASU). Process simulations clarify the influence of certain boundary conditions on plant operation, performance and economics. Based on that, a comparative benchmark of CC-IGCC concepts is conducted. Furthermore, the influence of integration between the gas turbine and the ASU is analyzed in detail. The generated findings are used to develop an advanced plant configuration with improved economics. Nevertheless, IGCC power plants with carbon capture are not found to be an economically efficient power generation technology at present day boundary conditions.

  4. Shell coal IGCCS with carbon capture: Conventional gas quench vs. innovative configurations

    International Nuclear Information System (INIS)

    Martelli, Emanuele; Kreutz, Thomas; Carbo, Michiel; Consonni, Stefano; Jansen, Daniel

    2011-01-01

    Highlights: → We aim at defining the preferred IGCC design for dry feed gasifiers with CO 2 capture. → Multiple options of syngas cooling, humidification, and WGS are considered. → Plants are designed, modeled, numerically optimized and costs are carefully assessed. → Partial water quench has poor efficiency but low capital cost, then good performance. → Gas quench with the ECN staged WGS design has the best thermo-economic performance. -- Abstract: The Shell coal integrated gasification combined cycle (IGCC) based on the gas quench system is one of the most fuel flexible and energy efficient gasification processes because is dry feed and employs high temperature syngas coolers capable of rising high pressure steam. Indeed the efficiency of a Shell IGCC with the best available technologies is calculated to be 47-48%. However the system looses many percentage points of efficiency (up to 10) when introducing carbon capture. To overcome this penalty, two approaches have been proposed. In the first, the expensive syngas coolers are replaced by a 'partial water quench' where the raw syngas stream is cooled and humidified via direct injection of hot water. This design is less costly, but also less efficient. The second approach retains syngas coolers but instead employs novel water-gas shift (WGS) configurations that requires substantially less steam to obtain the same degree of CO conversion to CO 2 , and thus increases the overall plant efficiency. We simulate and optimize these novel configurations, provide a detailed thermodynamic and economic analysis and investigate how these innovations alter the plant's efficiency, cost and complexity.

  5. Power and power-to-flow reactivity transfer functions in EBR-II [Experimental Breeder Reactor II] fuel

    International Nuclear Information System (INIS)

    Grimm, K.N.; Meneghetti, D.

    1989-01-01

    Reactivity transfer functions are important in determining the reactivity history during a power transient. Overall nodal transfer functions have been calculated for different subassembly types in the Experimental Breeder Reactor II (EBR-II). Steady-state calculations for temperature changes and, hence, reactivities for power changes have been separated into power and power-to-flow-dependent terms. Axial nodal transfer functions separated into power and power-to-flow-dependent components are reported in this paper for a typical EBR-II fuel pin. This provides an improved understanding of the time dependence of these components in transient situations

  6. A Hybrid Genetic Algorithm Approach for Optimal Power Flow

    Directory of Open Access Journals (Sweden)

    Sydulu Maheswarapu

    2011-08-01

    Full Text Available This paper puts forward a reformed hybrid genetic algorithm (GA based approach to the optimal power flow. In the approach followed here, continuous variables are designed using real-coded GA and discrete variables are processed as binary strings. The outcomes are compared with many other methods like simple genetic algorithm (GA, adaptive genetic algorithm (AGA, differential evolution (DE, particle swarm optimization (PSO and music based harmony search (MBHS on a IEEE30 bus test bed, with a total load of 283.4 MW. Its found that the proposed algorithm is found to offer lowest fuel cost. The proposed method is found to be computationally faster, robust, superior and promising form its convergence characteristics.

  7. Inductive-energy power flow for X-ray sources

    International Nuclear Information System (INIS)

    Ware, K.D.; Filios, P.G.; Gullickson, R.L.; Hebert, M.P.; Rowley, J.E.; Schneider, R.F.; Summa, W.J.; Vitkovski, I.M.

    1996-01-01

    The Defense Nuclear Agency (DNA) has been developing inductive energy storage (IES) technology for generating intense x-rays from electron beam-target interactions and from plasma radiating sources (PRS). Because of the complex interaction between the commutation of the current from the plasma and the stable dissipation of the energy in the load, DNA has supported several variations of power flow technology. Major variations include: (1) current interruption using a plasma opening switch (POS); (2) continuous current commutation through current-plasma motion against neutral, ionized, or magnetized medium [i.e., dense plasma focus-like (DPF) and plasma flow switch (PFS) technologies]; and, in addition, possible benefits of (3) directly driven complex PRS loads are being investigated. DNA programs include experimental and theoretical modeling and analysis with investigations (1) on Hawk and a Decade module in conjunction with the development of the bremsstrahlung sources (BRS), and (2) on Hawk, ACE-4 and Shiva-Star, as well as cooperative research on GIT-4 and GIT-8, in conjunction with PRS. (author). 1 tab., 12 figs., 17 refs

  8. Inductive-energy power flow for X-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Ware, K D; Filios, P G; Gullickson, R L; Hebert, M P; Rowley, J E; Schneider, R F; Summa, W J [Defense Nuclear Agency, Alexandria, VA (United States); Vitkovski, I M [Logicon RDA, Arlington, VA (United States)

    1997-12-31

    The Defense Nuclear Agency (DNA) has been developing inductive energy storage (IES) technology for generating intense x-rays from electron beam-target interactions and from plasma radiating sources (PRS). Because of the complex interaction between the commutation of the current from the plasma and the stable dissipation of the energy in the load, DNA has supported several variations of power flow technology. Major variations include: (1) current interruption using a plasma opening switch (POS); (2) continuous current commutation through current-plasma motion against neutral, ionized, or magnetized medium [i.e., dense plasma focus-like (DPF) and plasma flow switch (PFS) technologies]; and, in addition, possible benefits of (3) directly driven complex PRS loads are being investigated. DNA programs include experimental and theoretical modeling and analysis with investigations (1) on Hawk and a Decade module in conjunction with the development of the bremsstrahlung sources (BRS), and (2) on Hawk, ACE-4 and Shiva-Star, as well as cooperative research on GIT-4 and GIT-8, in conjunction with PRS. (author). 1 tab., 12 figs., 17 refs.

  9. Multi-Objective Differential Evolution for Voltage Security Constrained Optimal Power Flow in Deregulated Power Systems

    Science.gov (United States)

    Roselyn, J. Preetha; Devaraj, D.; Dash, Subhransu Sekhar

    2013-11-01

    Voltage stability is an important issue in the planning and operation of deregulated power systems. The voltage stability problems is a most challenging one for the system operators in deregulated power systems because of the intense use of transmission line capabilities and poor regulation in market environment. This article addresses the congestion management problem avoiding offline transmission capacity limits related to voltage stability by considering Voltage Security Constrained Optimal Power Flow (VSCOPF) problem in deregulated environment. This article presents the application of Multi Objective Differential Evolution (MODE) algorithm to solve the VSCOPF problem in new competitive power systems. The maximum of L-index of the load buses is taken as the indicator of voltage stability and is incorporated in the Optimal Power Flow (OPF) problem. The proposed method in hybrid power market which also gives solutions to voltage stability problems by considering the generation rescheduling cost and load shedding cost which relieves the congestion problem in deregulated environment. The buses for load shedding are selected based on the minimum eigen value of Jacobian with respect to the load shed. In the proposed approach, real power settings of generators in base case and contingency cases, generator bus voltage magnitudes, real and reactive power demands of selected load buses using sensitivity analysis are taken as the control variables and are represented as the combination of floating point numbers and integers. DE/randSF/1/bin strategy scheme of differential evolution with self-tuned parameter which employs binomial crossover and difference vector based mutation is used for the VSCOPF problem. A fuzzy based mechanism is employed to get the best compromise solution from the pareto front to aid the decision maker. The proposed VSCOPF planning model is implemented on IEEE 30-bus system, IEEE 57 bus practical system and IEEE 118 bus system. The pareto optimal

  10. Optimal power flow for distribution networks with distributed generation

    Directory of Open Access Journals (Sweden)

    Radosavljević Jordan

    2015-01-01

    Full Text Available This paper presents a genetic algorithm (GA based approach for the solution of the optimal power flow (OPF in distribution networks with distributed generation (DG units, including fuel cells, micro turbines, diesel generators, photovoltaic systems and wind turbines. The OPF is formulated as a nonlinear multi-objective optimization problem with equality and inequality constraints. Due to the stochastic nature of energy produced from renewable sources, i.e. wind turbines and photovoltaic systems, as well as load uncertainties, a probabilisticalgorithm is introduced in the OPF analysis. The Weibull and normal distributions are employed to model the input random variables, namely the wind speed, solar irradiance and load power. The 2m+1 point estimate method and the Gram Charlier expansion theory are used to obtain the statistical moments and the probability density functions (PDFs of the OPF results. The proposed approach is examined and tested on a modified IEEE 34 node test feeder with integrated five different DG units. The obtained results prove the efficiency of the proposed approach to solve both deterministic and probabilistic OPF problems for different forms of the multi-objective function. As such, it can serve as a useful decision-making supporting tool for distribution network operators. [Projekat Ministarstva nauke Republike Srbije, br. TR33046

  11. Distributed routing algorithms to manage power flow in agent-based active distribution network

    NARCIS (Netherlands)

    Nguyen, H.P.; Kling, W.L.; Georgiadis, G.; Papatriantafilou, M.; Anh-Tuan, L.; Bertling, L.

    2010-01-01

    The current transition from passive to active electric distribution networks comes with problems and challenges on bi-directional power flow in the network and the uncertainty in the forecast of power generation from grid-connected renewable and distributed energy sources. The power flow management

  12. A PSO based unified power flow controller for damping of power system oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Shayeghi, H. [Technical Engineering Dept., Univ. of Mohaghegh Ardabili, Daneshgah Street, P.O. Box 179, Ardabil (Iran); Shayanfar, H.A. [Center of Excellence for Power Automation and Operation, Electrical Engineering Dept., Iran Univ. of Science and Technology, Tehran (Iran); Jalilzadeh, S.; Safari, A. [Technical Engineering Dept., Zanjan Univ., Zanjan (Iran)

    2009-10-15

    On the basis of the linearized Phillips-Herffron model of a single-machine power system, we approach the problem of select the best input control signal of the unified power flow controller (UPFC) and design optimal UPFC based damping controller in order to enhance the damping of the power system low frequency oscillations. The potential of the UPFC supplementary controllers to enhance the dynamic stability is evaluated. This controller is tuned to simultaneously shift the undamped electromechanical modes to a prescribed zone in the s-plane. The problem of robustly UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multiobjective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using particle swarm optimization technique (PSO) that has a strong ability to find the most optimistic results. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed controller is demonstrated through eigenvalue analysis, nonlinear time-domain simulation and some performance indices studies. The results analysis reveals that the tuned PSO based UPFC controller using the proposed multiobjective function has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions show that the {delta}{sub E} based controller is superior to the m{sub B} based controller. (author)

  13. Magnetic insulation, power flow, and pulse power results on RITS-3

    International Nuclear Information System (INIS)

    Johnson, David L.; Smith, Ian; Corcoran, Patrick; Bailey, Vernon; Maenchen, John; Rovang, Dean; Molina, Isidro; Hahn, Kelly; Lucero, Robert; Kincy, Mark; Kitterman, David; Oliver, Bryan; Welch, Dale; Rose, David; Goldsack, Timothy J.; Phillips, Martin A.; Sinclair, Mark A.; Thomas, Kenneth J.

    2002-01-01

    RITS (Radiographic Integrated Test Stand) is an induction voltage adder designed by Sandia and PSD to provide 16-MV, 150-kA electron beams and other capabilities. Previous publications have reported on tests of a single pulse forming line and adder cell, including initial results of the effects of various degrees of non-uniform injection of current into the adder bore on magnetic insulation and power flow in the downstream MITL. Now RITS-3 has been constructed, consisting of three pfls driven by a common intermediate store; three induction cells, one driven by each pfl; a three-stage, 4-MV, 150-kA vacuum voltage adder; and an output MITL and diode. Here we report on (1) simulations of the three-stage adder using the MRC 3-D particle-in-cell code LSP that address the effects of injected current non-uniformities on magnetic insulation and power-flow both upstream and downstream in a multi-cell adder; (2) experimental results compared with simulations; and (3) initial performance of the RITS-3 pulse power

  14. MHD free convection flow of a non-Newtonian power-law fluid over ...

    African Journals Online (AJOL)

    ... flow have been presented for various parameters such as Prandtl number, flow behavior index (n), porous plate parameter and magnetic parameter. The local Nusselt number and skin friction coefficient is also presented graphically. Keywords: Magnetohydrodynamic flow; free convection flow; Non-Newtonian power-law

  15. Shell coal IGCCS with carbon capture. Conventional gas quench vs. innovative configurations

    Energy Technology Data Exchange (ETDEWEB)

    Martellia, E.; Consonni, S. [Politecnico di Milano, Via Scalabrini 76, Piacenza (Italy); Kreutz, T. [Princeton University, Guyot Hall, Room 129, Princeton, NJ (United States); Carbo, M.; Jansen, D. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG, Petten (Netherlands)

    2011-11-15

    The Shell coal integrated gasification combined cycle (IGCC) based on the gas quench system is one of the most fuel flexible and energy efficient gasification processes because is dry feed and employs high temperature syngas coolers capable of rising high pressure steam. Indeed the efficiency of a Shell IGCC with the best available technologies is calculated to be 47-48%. However the system looses many percentage points of efficiency (up to 10) when introducing carbon capture. To overcome this penalty, two approaches have been proposed. In the first, the expensive syngas coolers are replaced by a 'partial water quench' where the raw syngas stream is cooled and humidified via direct injection of hot water. This design is less costly, but also less efficient. The second approach retains syngas coolers but instead employs novel water-gas shift (WGS) configurations that requires substantially less steam to obtain the same degree of CO conversion to CO2, and thus increases the overall plant efficiency. We simulate and optimize these novel configurations, provide a detailed thermodynamic and economic analysis and investigate how these innovations alter the plant's efficiency, cost and complexity.

  16. Novel findings about management of gastric cancer: a summary from 10th IGCC.

    Science.gov (United States)

    Penon, Danila; Cito, Letizia; Giordano, Antonio

    2014-07-21

    The Tenth International Gastric Cancer Congress (IGCC) was held in Verona, Italy, from June 19 to 22, 2013. The meeting enclosed various aspects of stomach tumor management, including both tightly clinical approaches, and topics more related to basic research. Moreover, an overview on gastrointestinal stromal tumors was provided too, although here not discussed. Here we will discuss some topics related to molecular biology of gastric cancer (GC), inherent to prognostic, diagnostic and therapeutic tools shown at the conference. Results about well known subjects, such as E-cadherin loss of expression/function, were presented. They revealed that other mutations of the gene were identified, showing a continuous research to improve diagnosis and prognosis of stomach tumor. Simultaneously, new possible molecular markers with an established role for other neoplasms, were discussed, such as mesothelin, stomatin-like protein 2 and Notch-1. Hence, a wide overview including both old and new diagnostic/prognostic tools was offered. Great attention was also dedicated to possible drugs to be used against GC. They included monoclonal antibodies, such as MS57-2.1, drugs used in other pathologies, such as maraviroc, and natural extracts from plants such as biflorin. We would like to contribute to summarize the most impressive studies presented at the IGCC, concerning novel findings about molecular biology of gastric cancer. Although further investigations will be necessary, it can be inferred that more and more tools were developed, so as to better face stomach neoplasms.

  17. Flowing-water optical power meter for primary-standard, multi-kilowatt laser power measurements

    Science.gov (United States)

    Williams, P. A.; Hadler, J. A.; Cromer, C.; West, J.; Li, X.; Lehman, J. H.

    2018-06-01

    A primary-standard flowing-water optical power meter for measuring multi-kilowatt laser emission has been built and operated. The design and operational details of this primary standard are described, and a full uncertainty analysis is provided covering the measurement range from 1–10 kW with an expanded uncertainty of 1.2%. Validating measurements at 5 kW and 10 kW show agreement with other measurement techniques to within the measurement uncertainty. This work of the U.S. Government is not subject to U.S. copyright.

  18. Impact of Thyristors Controlled Series Capacitor Devices and Optimal Power Flow on Power Systems

    Directory of Open Access Journals (Sweden)

    Fatiha LAKDJA

    2010-12-01

    Full Text Available This paper presents an algorithm, for solving the Optimal Power Flow problem with flexible AC transmission systems (FACTS. The type of FACTS devices is used: thyristor-controlled series capacitor (TCSC. A method to determine the optimal location of thyristor controlled series compensators has been suggested. The proposed approaches have been implemented on an adapted IEEE 26 bus system. The simulation results are discussed to show the performance of the proposed algorithm and our “FACTS programmer “simulator technique, which are compared with TCSC and without TCSC.

  19. Integrated Power Flow and Short Circuit Calculation Method for Distribution Network with Inverter Based Distributed Generation

    OpenAIRE

    Yang, Shan; Tong, Xiangqian

    2016-01-01

    Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverte...

  20. Power flow controller with a fractionally rated back-to-back converter

    Science.gov (United States)

    Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish

    2016-03-08

    A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

  1. Advanced modeling and simulation of integrated gasification combined cycle power plants with CO{sub 2}-capture

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, Mathias

    2014-04-17

    The objective of this thesis is to provide an extensive description of the correlations in some of the most crucial sub-processes for hard coal fired IGCC with carbon capture (CC-IGCC). For this purpose, process simulation models are developed for four industrial gasification processes, the CO-shift cycle, the acid gas removal unit, the sulfur recovery process, the gas turbine, the water-/steam cycle and the air separation unit (ASU). Process simulations clarify the influence of certain boundary conditions on plant operation, performance and economics. Based on that, a comparative benchmark of CC-IGCC concepts is conducted. Furthermore, the influence of integration between the gas turbine and the ASU is analyzed in detail. The generated findings are used to develop an advanced plant configuration with improved economics. Nevertheless, IGCC power plants with carbon capture are not found to be an economically efficient power generation technology at present day boundary conditions.

  2. A novel symbiotic organisms search algorithm for optimal power flow of power system with FACTS devices

    Directory of Open Access Journals (Sweden)

    Dharmbir Prasad

    2016-03-01

    Full Text Available In this paper, symbiotic organisms search (SOS algorithm is proposed for the solution of optimal power flow (OPF problem of power system equipped with flexible ac transmission systems (FACTS devices. Inspired by interaction between organisms in ecosystem, SOS algorithm is a recent population based algorithm which does not require any algorithm specific control parameters unlike other algorithms. The performance of the proposed SOS algorithm is tested on the modified IEEE-30 bus and IEEE-57 bus test systems incorporating two types of FACTS devices, namely, thyristor controlled series capacitor and thyristor controlled phase shifter at fixed locations. The OPF problem of the present work is formulated with four different objective functions viz. (a fuel cost minimization, (b transmission active power loss minimization, (c emission reduction and (d minimization of combined economic and environmental cost. The simulation results exhibit the potential of the proposed SOS algorithm and demonstrate its effectiveness for solving the OPF problem of power system incorporating FACTS devices over the other evolutionary optimization techniques that surfaced in the recent state-of-the-art literature.

  3. Power flow control strategy in distribution network for dc type distributed energy resource at load bus

    International Nuclear Information System (INIS)

    Hanif, A.; Choudhry, M.A.

    2013-01-01

    This research work presents a feed forward power flow control strategy in the secondary distribution network working in parallel with a DC type distributed energy resource (DER) unit with SPWM-IGBT Voltage Source Converter (VSC). The developed control strategy enables the VSC to be used as power flow controller at the load bus in the presence of utility supply. Due to the investigated control strategy, power flow control from distributed energy resource (DER) to common load bus is such that power flows to the load without facing any power quality problem. The technique has an added advantage of controlling power flow without having a dedicated power flow controller. The SPWM-IGBT VSC is serving the purpose of dc-ac converter as well as power flow controller. Simulations for a test system using proposed power flow control strategy are carried out using SimPower Systems toolbox of MATLAB at the rate and Simulink at the rate. The results show that a reliable, effective and efficient operation of DC type DER unit in coordination with main utility network can be achieved. (author)

  4. Impact of Negative Reactance on Definiteness of B-Matrix and Feasibility of DC Power Flow

    DEFF Research Database (Denmark)

    Ding, Tao; Bo, Rui; Yang, Yongheng

    2018-01-01

    This paper reports an essential phenomenon on the existence of “negative reactance” in practical power system models. The negative reactance issue is important, as it could affect the definiteness of the B admittance matrix of power networks and the feasibility of DC power flow. With the graph th...... in “physical dis-connectivity” and make the linear system singular, so that the DC power flow will be infeasible. The results on several test systems show that the location and value of the negative reactance affect the DC power flow feasibility....

  5. Optimal power flow application issues in the Pool paradigm

    International Nuclear Information System (INIS)

    Gross, G.; Bompard, E.

    2004-01-01

    This paper focuses on the application of the Optimal Power Flow (OPF) to competitive markets. Since the OPF is a central decision-making tool its application to the more decentralized decision-making in the competitive electricity markets requires considerable care. There are some intrinsic challenges associated with the effective OPF application in the competitive environment due to the inherent characteristics of the OPF formulation. Two such characteristics are the flatness of the optimum surface and the consequent continuum associated with the optimum. In addition to these OPF structural characteristics, the level of authority vested in the central decision-making entity has major ramifications. These factors have wide ranging economic impacts, whose implications are very pronounced due to the fact that, unlike in the old vertically integrated utility environment, various market players are affected differently. The effects include price volatility, financial health of various players and the integrity of the market itself. We apply appropriate metrics to evaluate market efficiency and how the various players fare. We study the impacts of OPF applications in the Pool paradigm, with both supply and demand side explicitly modeled, and provide extensive numerical results on systems based on IEEE 30-bus and 118-bus networks. The results show the variability of nodal prices and the skew possible in different 'optimal' allocations among competing suppliers. Such variability in the results may lead to serious disputes among the players and the central decision-making authority. Directions for future research are discussed. (author)

  6. The entropy concept. A powerful tool for multiphase flow analysis

    International Nuclear Information System (INIS)

    Kolev, Nikolay Ivanov

    2007-01-01

    This work summarizes the system of partial differential equations describing multiphase, multi-component flows in arbitrary geometry including porous structures with arbitrary thermal and mechanical interactions among the fields and between each field and the structure. Each of the fluids is designed as a universal mixture of miscible and immiscible component. The system contains the rigorously derived entropy equations which are used instead of the primitive form of the energy conservation. Based on well established mathematical theorems the equations are local volume and time averaged. The so called volume conservation equation allowing establishing close coupling between pressure and density changes of all of the participating velocity fields is presented. It replaces one of the mass conservation equations. The system is solved within the computer code system IVA together with large number of constitutive relationships for closing it in arbitrary geometry. The extensive validation on many hundreds of simple- and complex experiments, including the many industrial applications, demonstrates the versatility and the power of this analytical tool for designing complex processes in the industry and analyzing complex processes in the nature. (author)

  7. Two phase flow problems in power station boilers

    International Nuclear Information System (INIS)

    Firman, E.C.

    1974-01-01

    The paper outlines some of the waterside thermal and hydrodynamic phenomena relating to design and operation of large boilers in central power stations. The associated programme of work is described with an outline of some results already obtained. By way of introduction, the principal features of conventional and nuclear drum boilers and once-through nuclear heat exchangers are described in so far as they pertain to this area of work. This is followed by discussion of the relevant physical phenomena and problems which arise. For example, the problem of steam entrainment from the drum into the tubes connecting it to the furnace wall tubes is related to its effects on circulation and possible mechanisms of tube failure. Other problems concern the transient associated with start-up or low load operation of plant. The requirement for improved mathematical representation of steady and dynamic performance is mentioned together with the corresponding need for data on heat transfer, pressure loss, hydrodynamic stability, consequences of deposits, etc. The paper concludes with reference to the work being carried out within the C.E.G.B. in relation to the above problems. The facilities employed and the specific studies being made on them are described: these range from field trials on operational boilers to small scale laboratory investigations of underlying two phase flow mechanisms and include high pressure water rigs and a freon rig for simulation studies

  8. TradeWind Deliverable 5.1: Effects of increasing wind power penetration on the power flows in European grids

    DEFF Research Database (Denmark)

    Lemström, Bettina; Uski-Joutsenvuo, Sanna; Holttinen, Hannele

    2008-01-01

    This report presents the main activities and results of Work Package 5 – Effects of increasing wind power penetration on the power flows in European grids in the TradeWind project. VTT is the leader of Work Package 5 and carries the overall responsibility of this report. The work is based on power...... flow simulations with a grid and market model developed in TradeWind Work Package 3, led by Sintef Energy Research. VTT, Sintef Energy Research and Risø have carried out the simulations of the different scenarios, analysed the results and written Chapter 4 about the impact of wind power on cross...

  9. Reproduction of the flow-power map of the Laguna Verde power plant

    International Nuclear Information System (INIS)

    Amador G, R.; Gonzalez M, V.M.

    1993-01-01

    The National Commission of Nuclear Safety and Safeguards (CNSNS) requires to have calculation tools which allows it to make analysis independent of the behavior of the reactor core of Laguna Verde nuclear power plant (CNLV) with the purpose to support the evaluation and discharge activities of the fuel recharges licensing. The software package Fms (Fuel Management System) allows to carry out an analysis of the core of the BWR type reactors along the operation cycle to detect possible anomalies and/or helping in the fuel management. In this work it is reproduced the flow-power for the CNLV using the Presto code of the Fms software package. The comparison of results with the map used by the operators of CNLV shows good agreement between them. Another exercise carried out was the changes study that the axial and radial power outlines undergo as well as the thermohydraulic parameters (LHGR, APLHGR, CPR) when moving a control rod. The obtained results show that is had the experience to effect analysis of the reactor behavior using the Presto-Fms code therefore the study of the rest of the software package for the obtention of nuclear parameters used in this code is recommended. (Author)

  10. A market power model with price caps and compact DC power flow constraints

    Energy Technology Data Exchange (ETDEWEB)

    Zuwei Yu [Purdue University, West Lafayette, IN (United States). School of Industrial Engineering

    2003-05-01

    This paper presents a spatial gaming model with price caps for deregulated electricity markets. There has been heated debate on price caps that have been enforced in deregulated electricity markets. Opponents argue that price caps may send wrong economic signals while advocates argue that price caps are good for damping market power. This paper does not intend to take a stand in the argument. Given the fact that price caps are enforced in several deregulated regional electricity markets in the US, a logical step is to reflect this reality in gaining modeling. However, current gaining models have not included any price cap formulation. This paper is the first one to address the issue. DC power flow equations are used for representing the spatial nature of an electrical network. An algorithm is proposed to find a generalized Nash equilibrium under the enforcement of price caps based on the Kuhn-Tucker Vector Optimization Theorem. Case studies show the successful application of the model. The conclusion is that market power impact can be reduced under appropriate price caps. (author)

  11. Technical, environmental, and economic assessment of deploying advanced coal power technologies in the Chinese context

    International Nuclear Information System (INIS)

    Zhao Lifeng; Xiao Yunhan; Gallagher, Kelly Sims; Wang Bo; Xu Xiang

    2008-01-01

    The goal of this study is to evaluate the technical, environmental, and economic dimensions of deploying advanced coal-fired power technologies in China. In particular, we estimate the differences in capital cost and overall cost of electricity (COE) for a variety of advanced coal-power technologies based on the technological and economic levels in 2006 in China. This paper explores the economic gaps between Integrated Gasification Combined Cycle (IGCC) and other advanced coal power technologies, and compares 12 different power plant configurations using advanced coal power technologies. Super critical (SC) and ultra super critical (USC) pulverized coal (PC) power generation technologies coupled with pollution control technologies can meet the emission requirements. These technologies are highly efficient, technically mature, and cost-effective. From the point of view of efficiency, SC and USC units are good choices for power industry. The net plant efficiency for IGCC has reached 45%, and it has the best environmental performance overall. The cost of IGCC is much higher, however, than that of other power generation technologies, so the development of IGCC is slow throughout the world. Incentive policies are needed if IGCC is to be deployed in China

  12. Scalable Newton-Krylov solver for very large power flow problems

    NARCIS (Netherlands)

    Idema, R.; Lahaye, D.J.P.; Vuik, C.; Van der Sluis, L.

    2010-01-01

    The power flow problem is generally solved by the Newton-Raphson method with a sparse direct solver for the linear system of equations in each iteration. While this works fine for small power flow problems, we will show that for very large problems the direct solver is very slow and we present

  13. Wave propagation and power flow in an acoustic metamaterial plate with lateral local resonance attachment

    Science.gov (United States)

    Wang, Ting; Sheng, Meiping; Ding, Xiaodong; Yan, Xiaowei

    2018-03-01

    This paper presents analysis on wave propagation and power flow in an acoustic metamaterial plate with lateral local resonance. The metamaterial is designed to have lateral local resonance systems attached to a homogeneous plate. Relevant theoretical analysis, numerical modelling and application prospect are presented. Results show that the metamaterial has two complete band gaps for flexural wave absorption and vibration attenuation. Damping can smooth and lower the metamaterial’s frequency responses in high frequency ranges at the expense of the band gap effect, and as an important factor to calculate the power flow is thoroughly investigated. Moreover, the effective mass density becomes negative and unbounded at specific frequencies. Simultaneously, power flow within band gaps are dramatically blocked from the power flow contour and power flow maps. Results from finite element modelling and power flow analysis reveal the working mechanism of the flexural wave attenuation and power flow blocked within the band gaps, where part of the flexural vibration is absorbed by the vertical resonator and the rest is transformed through four-link-mechanisms to the lateral resonators that oscillate and generate inertial forces indirectly to counterbalance the shear forces induced by the vibrational plate. The power flow is stored in the vertical and lateral local resonance, as well as in the connected plate.

  14. Flow angle dependent photoacoustic Doppler power spectra under intensity-modulated continuous wave laser excitation

    Directory of Open Access Journals (Sweden)

    Yu Tong

    2016-02-01

    Full Text Available Photoacoustic Doppler (PAD power spectra showing an evident Doppler shift represent the major characteristics of the continuous wave-excited or burst wave-excited versions of PAD flow measurements. In this paper, the flow angle dependences of the PAD power spectra are investigated using an experiment setup that was established based on intensity-modulated continuous wave laser excitation. The setup has an overall configuration that is similar to a previously reported configuration, but is more sophisticated in that it accurately aligns the laser illumination with the ultrasound detection process, and in that it picks up the correct sample position. In the analysis of the power spectra data, we find that the background power spectra can be extracted by combining the output signals from the two channels of the lock-in amplifier, which is very useful for identification of the PAD power spectra. The power spectra are presented and analyzed in opposite flow directions, at different flow speeds, and at different flow angles. The power spectra at a 90° flow angle show the unique properties of symmetrical shapes due to PAD broadening. For the other flow angles, the smoothed power spectra clearly show a flow angle cosine relationship.

  15. PIC simulation of the vacuum power flow for a 5 terawatt, 5 MV, 1 MA pulsed power system

    Science.gov (United States)

    Liu, Laqun; Zou, Wenkang; Liu, Dagang; Guo, Fan; Wang, Huihui; Chen, Lin

    2018-03-01

    In this paper, a 5 Terawatt, 5 MV, 1 MA pulsed power system based on vacuum magnetic insulation is simulated by the particle-in-cell (PIC) simulation method. The system consists of 50 100-kV linear transformer drive (LTD) cavities in series, using magnetically insulated induction voltage adder (MIVA) technology for pulsed power addition and transmission. The pulsed power formation and the vacuum power flow are simulated when the system works in self-limited flow and load-limited flow. When the pulsed power system isn't connected to the load, the downstream magnetically insulated transmission line (MITL) works in the self-limited flow, the maximum of output current is 1.14 MA and the amplitude of voltage is 4.63 MV. The ratio of the electron current to the total current is 67.5%, when the output current reached the peak value. When the impedance of the load is 3.0 Ω, the downstream MITL works in the self-limited flow, the maximums of output current and the amplitude of voltage are 1.28 MA and 3.96 MV, and the ratio of the electron current to the total current is 11.7% when the output current reached the peak value. In addition, when the switches are triggered in synchronism with the passage of the pulse power flow, it effectively reduces the rise time of the pulse current.

  16. An iterative method for controlling reactive power flow in boundary transformers

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, Angel L.; Martinez, Jose L.; Riquelme, Jesus; Romero, Esther [Department of Electrical Engineering, University of Seville (Spain)

    2011-02-15

    This paper presents an operational tool designed to help the system operator to control the reactive power flow in transmission-subtransmission boundary transformers. The main objective is to determine the minimum number of control actions necessary to ensure that reactive power flows in transmission/subtransmission transformers remain within limits. The proposed iterative procedure combines the use of a linear programming problem and a load flow tool. The linear programming assumes a linear behaviour between dependent and control variables around an operating point, modelled with sensitivities. Experimental results regarding IEEE systems are provided comparing the performance of the proposed approach with that of a conventional optimal power flow. (author)

  17. Integration of power flow controlling devices and HVDC-systems into the optimal power flow; Integration von leistungsflusssteuernden Komponenten und HGUe-Systemen in die Leistungsflussoptimierung

    Energy Technology Data Exchange (ETDEWEB)

    Natemeyer, Hendrik; Scheufen, Martin; Roehder, Andreas; Schnettler, Armin [RWTH Aachen Univ. (Germany). Inst. fuer Hochspannungstechnik (IFHT)

    2012-07-01

    An integration of High Voltage Direct Current Transmission Systems (HVDC) or Flexible AC Transmission Systems (FACTS) into power systems enables the possibility to actively influence and control the corresponding power flows in the electrical network. The systemic benefits are a more efficient utilization of existing transmission capacities and improved controllability in fault situations. This paper introduces methods of a coordinative control of such devices and their representation in stationary power flow calculations including the control in (n-1)-cases. This might be a useful tool for the network operation, especially in face of more frequently occurring fast system changes. Examples of a corresponding implementation and application are provided. (orig.)

  18. Axial annular flow of power-law fluids - applicability of the limiting cases

    Czech Academy of Sciences Publication Activity Database

    Filip, Petr; David, Jiří

    2007-01-01

    Roč. 52, č. 4 (2007), s. 365-371 ISSN 0001-7043 R&D Projects: GA ČR GA103/06/1033 Institutional research plan: CEZ:AV0Z20600510 Keywords : Concentric annuli * Poiseuile flow * annular flow * power- law fluids * flow rate * pressure drop Subject RIV: BK - Fluid Dynamics

  19. Application of neural networks to validation of feedwater flow rate in a nuclear power plant

    International Nuclear Information System (INIS)

    Khadem, M.; Ipakchi, A.; Alexandro, F.J.; Colley, R.W.

    1993-01-01

    Feedwater flow rate measurement in nuclear power plants requires periodic calibration. This is due to the fact that the venturi surface condition of the feedwater flow rate sensor changes because of a chemical reaction between the surface coating material and the feedwater. Fouling of the venturi surface, due to this chemical reaction and the deposits of foreign materials, has been observed shortly after a clean venturi is put in operation. A fouled venturi causes an incorrect measurement of feedwater flow rate, which in turn results in an inaccurate calculation of the generated power. This paper presents two methods for verifying incipient and continuing fouling of the venturi of the feedwater flow rate sensors. Both methods are based on the use of a set of dissimilar process variables dynamically related to the feedwater flow rate variable. The first method uses a neural network to generate estimates of the feedwater flow rate readings. Agreement, within a given tolerance, of the feedwater flow rate instrument reading, and the corresponding neural network output establishes that the feedwater flow rate instrument is operating properly. The second method is similar to the first method except that the neural network predicts the core power which is calculated from measurements on the primary loop, rather than the feedwater flow rates. This core power is referred to the primary core power in this paper. A comparison of the power calculated from the feedwater flow measurements in the secondary loop, with the calculated and neural network predicted primary core power provides information from which it can be determined whether fouling is beginning to occur. The two methods were tested using data from the feedwater flow meters in the two feedwater flow loops of the TMI-1 nuclear power plant

  20. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  1. Optimal power flow by particle swarm optimization with an aging ...

    African Journals Online (AJOL)

    In this paper, a particle swarm optimization (PSO) with an aging leader and challengers (ALC-PSO) is applied for the solution of OPF problem of power system. This study is implemented on modified IEEE 30-bus test power system with different objectives that reflect minimization of either fuel cost or active power loss or sum ...

  2. Newton-Krylov Methods in Power Flow and Contingency Analysis

    NARCIS (Netherlands)

    Idema, R.

    2012-01-01

    A power system is a system that provides for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems have to satisfy the highest security and

  3. An estimation of reactor thermal power uncertainty using UFM-based feedwater flow rate in nuclear power plants

    International Nuclear Information System (INIS)

    Byung Ryul Jung; Ho Cheol Jang; Byung Jin Lee; Se Jin Baik; Woo Hyun Jang

    2005-01-01

    Most of Pressurized Water Reactors (PWRs) utilize the venturi meters (VMs) to measure the feedwater (FW) flow rate to the steam generator in the calorimetric measurement, which is used in the reactor thermal power (RTP) estimation. However, measurement drifts have been experienced due to some anomalies on the venturi meter (generally called the venturi meter fouling). The VM's fouling tends to increase the measured pressure drop across the meter, which results in indication of increased feedwater flow rate. Finally, the reactor thermal power is overestimated and the actual reactor power is to be reduced to remain within the regulatory limits. To overcome this VM's fouling problem, the Ultrasonic Flow Meter (UFM) has recently been gaining attention in the measurement of the feedwater flow rate. This paper presents the applicability of a UFM based feedwater flow rate in the estimation of reactor thermal power uncertainty. The FW and RTP uncertainties are compared in terms of sensitivities between the VM- and UFM-based feedwater flow rates. Data from typical Optimized Power Reactor 1000 (OPR1000) plants are used to estimate the uncertainty. (authors)

  4. Dynamic Optimal Energy Flow in the Integrated Natural Gas and Electrical Power Systems

    DEFF Research Database (Denmark)

    Fang, Jiakun; Zeng, Qing; Ai, Xiaomeng

    2018-01-01

    . Simulation on the test case illustrates the success of the modelling and the beneficial roles of the power-to-gas are analyzed. The proposed model can be used in the decision support for both planning and operation of the coordinated natural gas and electrical power systems.......This work focuses on the optimal operation of the integrated gas and electrical power system with bi-directional energy conversion. Considering the different response times of the gas and power systems, the transient gas flow and steady- state power flow are combined to formulate the dynamic...... optimal energy flow in the integrated gas and power systems. With proper assumptions and simplifications, the problem is transformed into a single stage linear programming. And only a single stage linear programming is needed to obtain the optimal operation strategy for both gas and power systems...

  5. Millimeter-Gap Magnetically Insulated Transmission Line Power Flow Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hutsel, Brian Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stoltzfus, Brian S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fowler, William E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LeChien, Keith R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mazarakis, Michael G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, James K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mulville, Thomas D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Savage, Mark E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stygar, William A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McKenney, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Peter A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); MacRunnels, Diego J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Finis W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Porter, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An experiment platform has been designed to study vacuum power flow in magnetically insulated transmission lines (MITLs). The platform was driven by the 400-GW Mykonos-V accelerator. The experiments conducted quantify the current loss in a millimeter-gap MITL with respect to vacuum conditions in the MITL for two different gap distances, 1.0 and 1.3 mm. The current loss for each gap was measured for three different vacuum pump down times. As a ride along experiment, multiple shots were conducted with each set of hardware to determine if there was a conditioning effect to increase current delivery on subsequent shots. The experiment results revealed large differences in performance for the 1.0 and 1.3 mm gaps. The 1.0 mm gap resulted in current loss of 40%-60% of peak current. The 1.3 mm gap resulted in current losses of less than 5% of peak current. Classical MITL models that neglect plasma expansion predict that there should be zero current loss, after magnetic insulation is established, for both of these gaps. The experiments result s indicate that the vacuum pressure or pump down time did not have a significant effect on the measured current loss at vacuum pressures between 1e-4 and 1e-5 Torr. Additionally, there was not repeatable evidence of a conditioning effect that reduced current loss for subsequent full-energy shots on a given set of hardware. It should be noted that the experiments conducted likely did not have large loss contributions due to ion emission from the anode due to the relatively small current densi-ties (25-40 kA/cm) in the MITL that limited the anode temperature rise due to ohmic heating. The results and conclusions from these experiments may have limited applicability to MITLs of high current density (>400 kA/cm) used in the convolute and load region of the Z which experience temperature increases of >400° C and generate ion emission from anode surfaces.

  6. Non-intrusive accurate and traceable flow measurements in nuclear power plant systems

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, A.; Kanda, V.; Sharp, B.; Lopez, A. [Advanced Measurement and Analysis Group Inc., ON (Canada); Gurevich, Y. [Daystar Technologies Inc., ON (Canada)

    2014-07-01

    Ultrasonic cross correlation flow meters, are a non-intrusive flow measurement technology based on measurement of the transport velocity of turbulent structures, and have many advantages over other ultrasonic flow measurement methods. The cross correlation flow meter CROSSFLOW, produced and operated by the Canadian company Advanced Measurement and Analysis Group Inc., is used in nuclear power plants around the world, for various application. This paper describes the operating principals of the ultrasonic cross correlation flow meter, its advantages over other ultrasonic flow measurement methods, its application around the world. (author)

  7. Optimal power flow based on glow worm-swarm optimization for three-phase islanded microgrids

    DEFF Research Database (Denmark)

    Quang, Ninh Nguyen; Sanseverino, Eleonora Riva; Di Silvestre, Maria Luisa

    2014-01-01

    This paper presents an application of the Glowworm Swarm Optimization method (GSO) to solve the optimal power flow problem in three-phase islanded microgrids equipped with power electronics dc-ac inverter interfaced distributed generation units. In this system, the power injected by the distribut...

  8. User Context Aware Base Station Power Flow Model

    OpenAIRE

    Walsh, Barbara; Farrell, Ronan

    2005-01-01

    At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

  9. Sludge pipe flow pressure drop prediction using composite power ...

    African Journals Online (AJOL)

    2011-09-30

    Sep 30, 2011 ... 3Department of Chemical Engineering, IIT Kanpur, India. Abstract. When predicting pressure gradients for the flow of sludges in pipes, the rheology of the fluid ..... implicit in the stability analysis of Ryan and Johnson (1959).

  10. On-line validation of feedwater flow rate in nuclear power plants using neural networks

    International Nuclear Information System (INIS)

    Khadem, M.; Ipakchi, A.; Alexandro, F.J.; Colley, R.W.

    1994-01-01

    On-line calibration of feedwater flow rate measurement in nuclear power plants provides a continuous realistic value of feedwater flow rate. It also reduces the manpower required for periodic calibration needed due to the fouling and defouling of the venturi meter surface condition. This paper presents a method for on-line validation of feedwater flow rate in nuclear power plants. The method is an improvement of the previously developed method which is based on the use of a set of process variables dynamically related to the feedwater flow rate. The online measurements of this set of variables are used as inputs to a neural network to obtain an estimate of the feedwater flow rate reading. The difference between the on-line feedwater flow rate reading, and the neural network estimate establishes whether there is a need to apply a correction factor to the feedwater flow rate measurement for calculation of the actual reactor power. The method was applied to the feedwater flow meters in the two feedwater flow loops of the TMI-1 nuclear power plant. The venturi meters used for flow measurements are susceptible to frequent fouling that degrades their measurement accuracy. The fouling effects can cause an inaccuracy of up to 3% relative error in feedwater flow rate reading. A neural network, whose inputs were the readings of a set of reference instruments, was designed to predict both feedwater flow rates simultaneously. A multi-layer feedforward neural network employing the backpropagation algorithm was used. A number of neural network training tests were performed to obtain an optimum filtering technique of the input/output data of the neural networks. The result of the selection of the filtering technique was confirmed by numerous Fast Fourier Transform (FFT) tests. Training and testing were done on data from TMI-1 nuclear power plant. The results show that the neural network can predict the correct flow rates with an absolute relative error of less than 2%

  11. Study of the heat transport primary system flow of Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Coutsiers, Eduardo E.; Moreno, Carlos A.; Pomerantz, Marcelo E.

    1999-01-01

    In this work, the HTPS coolant channels flow and associate aleatory errors are estimated. The objective of this estimation is to verify the validity of the flow calculated using the Canadian thermalhydraulic design code 'NUCIRC'. From measurements it can also be observed the evolution of the calculated flow with power of the reactor and to correct the maximum flow with power. The percentage of standard deviation discrepancies of flow estimated by measurements and those calculated using NUCIRC code is 5,7%. As the average aleatory error in flow estimation is 8,0%, it is concluded that the flow distribution calculated using NUCIRC is representative of the current state of the reactor channels. (author)

  12. Assessment of Power Potential of Tidal Currents and Impacts of Power Extraction on Flow Speeds in Indonesia

    Science.gov (United States)

    Orhan, K.; Mayerle, R.

    2016-12-01

    A methodology comprising of the estimates of power yield, evaluation of the effects of power extraction on flow conditions, and near-field investigations to deliver wake characteritics, recovery and interactions is described and applied to several straits in Indonesia. Site selection is done with high-resolution, three-dimensional flow models providing sufficient spatiotemporal coverage. Much attention has been given to the meteorological forcing, and conditions at the open sea boundaries to adequately capture the density gradients and flow fields. Model verification using tidal records shows excellent agreement. Sites with adequate depth for the energy conversion using horizontal axis tidal turbines, average kinetic power density greater than 0.5 kW/m2, and surface area larger than 0.5km2 are defined as energy hotspots. Spatial variation of the average extractable electric power is determined, and annual tidal energy resource is estimated for the straits in question. The results showed that the potential for tidal power generation in Indonesia is likely to exceed previous predictions reaching around 4,800MW. To assess the impact of the devices, flexible mesh models with higher resolutions have been developed. Effects on flow conditions, and near-field turbine wakes are resolved in greater detail with triangular horizontal grids. The energy is assumed to be removed uniformly by sub-grid scale arrays of turbines, and calculations are made based on velocities at the hub heights of the devices. An additional drag force resulting in dissipation of the pre-existing kinetic power from %10 to %60 within a flow cross-section is introduced to capture the impacts. It was found that the effect of power extraction on water levels and flow speeds in adjacent areas is not significant. Results show the effectivess of the method to capture wake characteritics and recovery reasonably well with low computational cost.

  13. Wind farm electrical power production model for load flow analysis

    International Nuclear Information System (INIS)

    Segura-Heras, Isidoro; Escriva-Escriva, Guillermo; Alcazar-Ortega, Manuel

    2011-01-01

    The importance of renewable energy increases in activities relating to new forms of managing and operating electrical power: especially wind power. Wind generation is increasing its share in the electricity generation portfolios of many countries. Wind power production in Spain has doubled over the past four years and has reached 20 GW. One of the greatest problems facing wind farms is that the electrical power generated depends on the variable characteristics of the wind. To become competitive in a liberalized market, the reliability of wind energy must be guaranteed. Good local wind forecasts are therefore essential for the accurate prediction of generation levels for each moment of the day. This paper proposes an electrical power production model for wind farms based on a new method that produces correlated wind speeds for various wind farms. This method enables a reliable evaluation of the impact of new wind farms on the high-voltage distribution grid. (author)

  14. Fractionating power and outlet stream polydispersity in asymmetrical flow field-flow fractionation. Part I: isocratic operation.

    Science.gov (United States)

    Williams, P Stephen

    2016-05-01

    Asymmetrical flow field-flow fractionation (As-FlFFF) has become the most commonly used of the field-flow fractionation techniques. However, because of the interdependence of the channel flow and the cross flow through the accumulation wall, it is the most difficult of the techniques to optimize, particularly for programmed cross flow operation. For the analysis of polydisperse samples, the optimization should ideally be guided by the predicted fractionating power. Many experimentalists, however, neglect fractionating power and rely on light scattering detection simply to confirm apparent selectivity across the breadth of the eluted peak. The size information returned by the light scattering software is assumed to dispense with any reliance on theory to predict retention, and any departure of theoretical predictions from experimental observations is therefore considered of no importance. Separation depends on efficiency as well as selectivity, however, and efficiency can be a strong function of retention. The fractionation of a polydisperse sample by field-flow fractionation never provides a perfectly separated series of monodisperse fractions at the channel outlet. The outlet stream has some residual polydispersity, and it will be shown in this manuscript that the residual polydispersity is inversely related to the fractionating power. Due to the strong dependence of light scattering intensity and its angular distribution on the size of the scattering species, the outlet polydispersity must be minimized if reliable size data are to be obtained from the light scattering detector signal. It is shown that light scattering detection should be used with careful control of fractionating power to obtain optimized analysis of polydisperse samples. Part I is concerned with isocratic operation of As-FlFFF, and part II with programmed operation.

  15. Unconfined Unsteady Laminar Flow of a Power-Law Fluid across a Square Cylinder

    Directory of Open Access Journals (Sweden)

    Asterios Pantokratoras

    2016-11-01

    Full Text Available The flow of a non-Newtonian, power-law fluid, directed normally to a horizontal cylinder with square cross-section (two-dimensional flow is considered in the present paper. The problem is investigated numerically with a very large calculation domain in order that the flow could be considered unconfined. The investigation covers the power-law index from 0.1 up to 2 and the Reynolds number ranges from 60 to 160. Over this range of Reynolds numbers the flow is unsteady. It is found that the drag coefficient and the Strouhal number are higher in a confined flow compared to those of an unconfined flow. In addition some flow characteristics are lost in a confined flow. Complete results for the drag coefficient and Strouhal number in the entire shear-thinning and shear-thickening region have been produced. In shear-thinning fluids chaotic structures exist which diminish at higher values of power-law index. This study represents the first investigation of unsteady, non-Newtonian power-law flow past a square cylinder in an unconfined field.

  16. Estimating the vibration level of an L-shaped beam using power flow techniques

    Science.gov (United States)

    Cuschieri, J. M.; Mccollum, M.; Rassineux, J. L.; Gilbert, T.

    1986-01-01

    The response of one component of an L-shaped beam, with point force excitation on the other component, is estimated using the power flow method. The transmitted power from the source component to the receiver component is expressed in terms of the transfer and input mobilities at the excitation point and the joint. The response is estimated both in narrow frequency bands, using the exact geometry of the beams, and as a frequency averaged response using infinite beam models. The results using this power flow technique are compared to the results obtained using finite element analysis (FEA) of the L-shaped beam for the low frequency response and to results obtained using statistical energy analysis (SEA) for the high frequencies. The agreement between the FEA results and the power flow method results at low frequencies is very good. SEA results are in terms of frequency averaged levels and these are in perfect agreement with the results obtained using the infinite beam models in the power flow method. The narrow frequency band results from the power flow method also converge to the SEA results at high frequencies. The advantage of the power flow method is that detail of the response can be retained while reducing computation time, which will allow the narrow frequency band analysis of the response to be extended to higher frequencies.

  17. Optimal Power Flow in Microgrids with Energy Storage

    DEFF Research Database (Denmark)

    Levron, Yoash; Guerrero, Josep M.; Beck, Yuval

    2013-01-01

    Energy storage may improve power management in microgrids that include renewable energy sources. The storage devices match energy generation to consumption, facilitating a smooth and robust energy balance within the microgrid. This paper addresses the optimal control of the microgrid’s energy...... storage devices. Stored energy is controlled to balance power generation of renewable sources to optimize overall power consumption at the microgrid point of common coupling. Recent works emphasize constraints imposed by the storage device itself, such as limited capacity and internal losses. However...

  18. Different scenarios to reduce greenhouse gas emissions of thermal power stations in Canada

    International Nuclear Information System (INIS)

    Zabihian, F.; Fung, A.S.

    2009-01-01

    The purpose of this paper is to examine greenhouse gas (GHG) emission reduction potentials in the Canadian electricity generation sector through fuel switching and the adoption of advanced power generation systems. To achieve this purpose, six different scenarios were introduced. In the first scenario existing power stations' fuel was switched to natural gas. Existing power plants were replaced by natural gas combined cycle (NGCC), integrated gasification combined cycle (IGCC), solid oxide fuel cell (SOFC), hybrid SOFC, and SOFC-IGCC hybrid power stations in scenarios number 2 to 6, respectively. (author)

  19. Probabilistic Constrained Load Flow Considering Integration of Wind Power Generation and Electric Vehicles

    DEFF Research Database (Denmark)

    Vlachogiannis, Ioannis (John)

    2009-01-01

    A new formulation and solution of probabilistic constrained load flow (PCLF) problem suitable for modern power systems with wind power generation and electric vehicles (EV) demand or supply is represented. The developed stochastic model of EV demand/supply and the wind power generation model...... are incorporated into load flow studies. In the resulted PCLF formulation, discrete and continuous control parameters are engaged. Therefore, a hybrid learning automata system (HLAS) is developed to find the optimal offline control settings over a whole planning period of power system. The process of HLAS...

  20. Analysis and distributed control of power flow in DC microgrids to improve system efficiency

    DEFF Research Database (Denmark)

    Chen, Fang; Burgos, Rolando; Boroyevich, Dushan

    2016-01-01

    DC Microgrid attains popularity in integrating renewable energy sources and batteries. It also has the potential to achieve higher efficiency than ac power grid under the condition of optimized power flow. In this paper, a general dc microgrid is modeled based on a cluster of general dc nodes......, which includes constant power renewables generation, droop-controlled voltage source and different kinds of load. Then the dc power flow is solved for optimization. A voltage restoration method based on consensus communication is used to restore the voltage deviation from droop characteristic...

  1. Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

    Directory of Open Access Journals (Sweden)

    Ivković Sanja

    2014-01-01

    Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

  2. Multi-Time Scale Coordinated Scheduling Strategy with Distributed Power Flow Controllers for Minimizing Wind Power Spillage

    Directory of Open Access Journals (Sweden)

    Yi Tang

    2017-11-01

    Full Text Available The inherent variability and randomness of large-scale wind power integration have brought great challenges to power flow control and dispatch. The distributed power flow controller (DPFC has the higher flexibility and capacity in power flow control in the system with wind generation. This paper proposes a multi-time scale coordinated scheduling model with DPFC to minimize wind power spillage. Configuration of DPFCs is initially determined by stochastic method. Afterward, two sequential procedures containing day-head and real-time scales are applied for determining maximum schedulable wind sources, optimal outputs of generating units and operation setting of DPFCs. The generating plan is obtained initially in day-ahead scheduling stage and modified in real-time scheduling model, while considering the uncertainty of wind power and fast operation of DPFC. Numerical simulation results in IEEE-RTS79 system illustrate that wind power is maximum scheduled with the optimal deployment and operation of DPFC, which confirms the applicability and effectiveness of the proposed method.

  3. Technology and knowledge flow the power of networks

    CERN Document Server

    Trentin, Guglielmo

    2011-01-01

    This book outlines how network technology can support, foster and enhance the Knowledge Management, Sharing and Development (KMSD) processes in professional environments through the activation of both formal and informal knowledge flows. Understanding how ICT can be made available to such flows in the knowledge society is a factor that cannot be disregarded and is confirmed by the increasing interest of companies in new forms of software-mediated social interaction. The latter factor is in relation both to the possibility of accelerating internal communication and problem solving processes, an

  4. Solution of optimal power flow using evolutionary-based algorithms

    African Journals Online (AJOL)

    It aims to estimate the optimal settings of real generator output power, bus voltage, ...... Lansey, K. E., 2003, Optimization of water distribution network design using ... Pandit, M., 2016, Economic load dispatch of wind-solar-thermal system using ...

  5. EFFECTS OF UNIFIED POWER FLOW CONTROLLER (UPFC) ON ...

    African Journals Online (AJOL)

    eobe

    2015-10-04

    Oct 4, 2015 ... environment of Power System Computer Aided Design (PSCAD) and kept within the environment of ... operating characteristic of a mho distance relay, also known as ..... Concept and Technology of AC Transmission. System”.

  6. Optimal power flow by particle swarm optimization with an aging ...

    African Journals Online (AJOL)

    DR OKE

    2002), evolutionary programming (EP) (Somasundaram et al. ... concepts, a modified PSO called as PSO with aging leader and challenges (ALC-PSO) is ... system is adopted as standard power network whose OPF problem is solved with the ...

  7. The Transient Elliptic Flow of Power-Law Fluid in Fractal Porous Media

    Institute of Scientific and Technical Information of China (English)

    宋付权; 刘慈群

    2002-01-01

    The steady oil production and pressure distribution formulae of vertically fractured well for power-law non-Newtonian fluid were derived on the basis of the elliptic flow model in fractal reservoirs. The corresponding transient flow in fractal reservoirs was studied by numerical differentiation method: the influence of fractal index to transient pressure of vertically fractured well was analyzed. Finally the approximate analytical solution of transient flow was given by average mass conservation law. The study shows that using elliptic flow method to analyze the flow of vertically fractured well is a simple method.

  8. Modeling generalized interline power-flow controller (GIPFC using 48-pulse voltage source converters

    Directory of Open Access Journals (Sweden)

    Amir Ghorbani

    2018-05-01

    Full Text Available Generalized interline power-flow controller (GIPFC is one of the voltage-source controller (VSC-based flexible AC transmission system (FACTS controllers that can independently regulate the power-flow over each transmission line of a multiline system. This paper presents the modeling and performance analysis of GIPFC based on 48-pulsed voltage-source converters. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels voltage source converter. The voltage source converter described in this paper is a harmonic neutralized, 48-pulse GTO converter. The GIPFC controller is based on d-q orthogonal coordinates. The algorithm is verified using simulations in MATLAB/Simulink environment. Comparisons between unified power flow controller (UPFC and GIPFC are also included. Keywords: Generalized interline power-flow controller (GIPFC, Voltage source converter (VCS, 48-pulse GTO converter

  9. Distributed AC power flow method for AC and AC-DC hybrid ...

    African Journals Online (AJOL)

    DR OKE

    presented here that solves the power flow problem node-wise, minimizing losses and .... The process is continued till the nodal mismatch values are negligibly small. .... operation and control; FACTS controllers; deregulation; generations and ...

  10. Power flow modelling in electric networks with renewable energy sources in large areas

    International Nuclear Information System (INIS)

    Buhawa, Z. M.; Dvorsky, E.

    2012-01-01

    In many worlds regions there is a great potential for utilizing home grid connected renewable power generating systems, with capacities of MW thousands. The optimal utilization of these sources is connected with power flow possibilities trough the power network in which they have to be connected. There is necessary to respect the long distances among the electric power sources with great outputs and power consumption and non even distribution of the power sources as well. The article gives the solution possibilities for Libya region under utilization of wind renewable sources in north in shore regions. (Authors)

  11. Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo

    2012-12-31

    This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve

  12. Experimental modeling of swirl flows in power plants

    Science.gov (United States)

    Shtork, S. I.; Litvinov, I. V.; Gesheva, E. S.; Tsoy, M. A.; Skripkin, S. G.

    2018-03-01

    The article presents an overview of the methods and approaches to experimental modeling of various thermal and hydropower units - furnaces of pulverized coal boilers and flow-through elements of hydro turbines. The presented modeling approaches based on a combination of experimentation and rapid prototyping of working parts may be useful in optimizing energy equipment to improve safety and efficiency of industrial energy systems.

  13. Electrohydrodynamic stability of two stratified power law liquid in couette flow

    International Nuclear Information System (INIS)

    Eldabe, N.T.

    1988-01-01

    Consideration is given to the stability of the flow of two power law liquids under the influence of normal electric field between two infinite parallel planes when one of the planes moves with constant velocity in its own plane. It is found that the electric fields have a dramatic effect and can be chosen to stabilize or destabilize the flow. The effects of the power law parameters on the problem are examinated

  14. Development of a multi-path ultrasonic flow meter for the application to feedwater flow measurement in nuclear power plants

    International Nuclear Information System (INIS)

    Jong, J. C.; Ha, J. H.; Kim, Y. H.; Jang, W. H.; Park, K. S.; Park, M. S.; Park, M. H.

    2002-01-01

    In this work, we propose a method to measure the feedwater flow using multi-path ultrasonic flow meter (UFM). Since the UFM measures a path velocity at which the ultrasonic wave is propagated, the flow profile may be important to convey the path velocity to the velocity averaged over the entire cross section of the flowing medium. The conventional UFM has used the smooth-wall circular pipe model presented by Nikurades. However, this model covers a lower range which is less than 3.2 million while the Reynolds number of the feedwater flow in operating nuclear power plants (NPPs) is about 20 million. Therefore, we feedwater flow in operating nuclear power plants (NPPs) is about 20 million. Therefore, we proposed the non-linear correlation model that combines the ratio between the DP output and proposed the non-linear correlation model that combines the ratio between the DP output and UFM output. Experiments were performed using both computer simulation and newly constructed NPPs' test data. The uncertainty analysis result shows that the proposed method has reasonably lower uncertainty than conventional UFM

  15. The internal flow pattern analysis of a tidal power turbine operating on bidirectional generation-pumping

    International Nuclear Information System (INIS)

    Luo, Y Y; Xiao, Y X; Wang, Z W

    2013-01-01

    Using tidal energy can reduce environment pollution, save conventional energy and improve energy structure, hence it presents great advantage and is developing potential. Influenced by flood tide and low tide, a fully functional tidal power station needs to experience six operating modes, including bidirectional generation, pumping and sluice; the internal unsteady flow pattern and dynamic characters are very complicated. Based on a bidirectional tidal generator unit, three-dimensional unsteady flows in the flow path were calculated for four typical operating conditions with the pressure pulsation characteristics analyzed. According to the numerical results, the internal flow characteristics in the flow path were discussed. The influence of gravity to the hydraulic performance and flow characteristics were analysed. The results provide a theoretical analysis method of the hydraulic optimization design of the same type unit as well as a direction for stable operation and optimal scheduling of existing tidal power unit

  16. A Power System Optimal Dispatch Strategy Considering the Flow of Carbon Emissions and Large Consumers

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2015-08-01

    Full Text Available The carbon emissions trading market and direct power purchases by large consumers are two promising directions of power system development. To trace the carbon emission flow in the power grid, the theory of carbon emission flow is improved by allocating power loss to the load side. Based on the improved carbon emission flow theory, an optimal dispatch model is proposed to optimize the cost of both large consumers and the power grid, which will benefit from the carbon emissions trading market. Moreover, to better simulate reality, the direct purchase of power by large consumers is also considered in this paper. The OPF (optimal power flow method is applied to solve the problem. To evaluate our proposed optimal dispatch strategy, an IEEE 30-bus system is used to test the performance. The effects of the price of carbon emissions and the price of electricity from normal generators and low-carbon generators with regards to the optimal dispatch are analyzed. The simulation results indicate that the proposed strategy can significantly reduce both the operation cost of the power grid and the power utilization cost of large consumers.

  17. Simulation Results of Closed Loop Controlled Interline Power Flow Controller System

    Directory of Open Access Journals (Sweden)

    P. USHA RANI

    2016-01-01

    Full Text Available The Interline Power Flow Controller (IPFC is the latest generation of Flexible AC Transmission Systems (FACTS devices which can be used to control power flows of multiple transmission lines. A dispatch strategy is proposed for an IPFC operating at rated capacity, in which the power circulation between the two series converters is used as the parameter to optimize the voltage profile and power transfer. Voltage stability curves for test system are shown to illustrate the effectiveness of this proposed strategy. In this paper, a circuit model for IPFC is developed and simulation of interline power flow controller is done using the proposed circuit model. Simulation is done using MATLAB simulink and the results are presented.

  18. Grid-Connection Half-Bridge PV Inverter System for Power Flow Controlling and Active Power Filtering

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-01-01

    Full Text Available A half-bridge photovoltaic (PV system is proposed, which can not only deal with bidirectional power flowing but also improve power quality. According to varying insolation, the system conditions real power for dc and ac loads to accommodate different amounts of PV power. Furthermore, the system eliminates current harmonics and improves power factor simultaneously. As compared with conventional PV inverter, the total number of active switches and current sensors can be reduced so that its cost is lower significantly. For current command determination, a linear-approximation method (LAM is applied to avoid the complicated calculation and achieve the maximum power point tracking (MPPT feature. For current controlling, a direct-source-current-shaping (DSCS algorithm is presented to shape the waveform of line current. Simulation results and practical measurements also demonstrate the feasibility of the proposed half-bridge PV system.

  19. Method of critical power prediction based on film flow model coupled with subchannel analysis

    International Nuclear Information System (INIS)

    Tomiyama, Akio; Yokomizo, Osamu; Yoshimoto, Yuichiro; Sugawara, Satoshi.

    1988-01-01

    A new method was developed to predict critical powers for a wide variety of BWR fuel bundle designs. This method couples subchannel analysis with a liquid film flow model, instead of taking the conventional way which couples subchannel analysis with critical heat flux correlations. Flow and quality distributions in a bundle are estimated by the subchannel analysis. Using these distributions, film flow rates along fuel rods are then calculated with the film flow model. Dryout is assumed to occur where one of the film flows disappears. This method is expected to give much better adaptability to variations in geometry, heat flux, flow rate and quality distributions than the conventional methods. In order to verify the method, critical power data under BWR conditions were analyzed. Measured and calculated critical powers agreed to within ±7%. Furthermore critical power data for a tight-latticed bundle obtained by LeTourneau et al. were compared with critical powers calculated by the present method and two conventional methods, CISE correlation and subchannel analysis coupled with the CISE correlation. It was confirmed that the present method can predict critical powers more accurately than the conventional methods. (author)

  20. PROBABILISTIC FLOW DISTRIBUTION AS A REACTION TO THE STOCHASTICITY OF THE LOAD IN THE POWER SYSTEM

    Directory of Open Access Journals (Sweden)

    A. M. Hashimov

    2016-01-01

    Full Text Available For the analysis and control of power systems deterministic approaches that are implemented in the form of well-known methods and models of calculation of steady-state and transient modes are mostly use in current practice. With the use of these methods it is possible to obtain solutions only for fixed circuit parameters of the system scheme and assuming that active and reactive powers as well as generation in nodal points of the network remain the same. In reality the stochastic character of power consumption cause the casual fluctuations of voltages at the nodes and power flows in electric power lines of the power system. Such casual fluctuations of operation can be estimated with the use of probabilistic simulation of the power flows. In the article the results of research of the influence of depth of casual fluctuations of the load power of the system on the probability distribution of voltage at nodes as well as on the flows of active and reactive power in the lines are presented. Probabilistic modeling of flow under stochastic load change is performed for different levels of fluctuations and under loading of the mode of the system up to peak load power. Test study to quantify the effect of stochastic variability of loads on the probabilistic distribution parameters of the modes was carried out on behalf of the electrical network of the real power system. The results of the simulation of the probability flow distribution for these fluctuations of the load, represented in the form of discrete sample values of the active power obtained with the use of the analytical Monte-Carlo method, and real data measurements of their values in the network under examination were compared.

  1. DC microgrid power flow optimization by multi-layer supervision control. Design and experimental validation

    International Nuclear Information System (INIS)

    Sechilariu, Manuela; Wang, Bao Chao; Locment, Fabrice; Jouglet, Antoine

    2014-01-01

    Highlights: • DC microgrid (PV array, storage, power grid connection, DC load) with multi-layer supervision control. • Power balancing following power flow optimization while providing interface for smart grid communication. • Optimization under constraints: storage capability, grid power limitations, grid time-of-use pricing. • Experimental validation of DC microgrid power flow optimization by multi-layer supervision control. • DC microgrid able to perform peak shaving, to avoid undesired injection, and to make full use of locally energy. - Abstract: Urban areas have great potential for photovoltaic (PV) generation, however, direct PV power injection has limitations for high level PV penetration. It induces additional regulations in grid power balancing because of lacking abilities of responding to grid issues such as reducing grid peak consumption or avoiding undesired injections. The smart grid implementation, which is designed to meet these requirements, is facilitated by microgrids development. This paper presents a DC microgrid (PV array, storage, power grid connection, DC load) with multi-layer supervision control which handles instantaneous power balancing following the power flow optimization while providing interface for smart grid communication. The optimization takes into account forecast of PV power production and load power demand, while satisfying constraints such as storage capability, grid power limitations, grid time-of-use pricing and grid peak hour. Optimization, whose efficiency is related to the prediction accuracy, is carried out by mixed integer linear programming. Experimental results show that the proposed microgrid structure is able to control the power flow at near optimum cost and ensures self-correcting capability. It can respond to issues of performing peak shaving, avoiding undesired injection, and making full use of locally produced energy with respect to rigid element constraints

  2. Congestion management of deregulated power systems by optimal setting of Interline Power Flow Controller using Gravitational Search algorithm

    Directory of Open Access Journals (Sweden)

    Akanksha Mishra

    2017-05-01

    Full Text Available In a deregulated electricity market it may at times become difficult to dispatch all the required power that is scheduled to flow due to congestion in transmission lines. An Interline Power Flow Controller (IPFC can be used to reduce the system loss and power flow in the heavily loaded line, improve stability and loadability of the system. This paper proposes a Disparity Line Utilization Factor for the optimal placement and Gravitational Search algorithm based optimal tuning of IPFC to control the congestion in transmission lines. DLUF ranks the transmission lines in terms of relative line congestion. The IPFC is accordingly placed in the most congested and the least congested line connected to the same bus. Optimal sizing of IPFC is carried using Gravitational Search algorithm. A multi-objective function has been chosen for tuning the parameters of the IPFC. The proposed method is implemented on an IEEE-30 bus test system. Graphical representations have been included in the paper showing reduction in LUF of the transmission lines after the placement of an IPFC. A reduction in active power and reactive power loss of the system by about 6% is observed after an optimally tuned IPFC has been included in the power system. The effectiveness of the proposed tuning method has also been shown in the paper through the reduction in the values of the objective functions.

  3. Developed generalised unified power flow controller model in the Newton–Raphson power-flow analysis using combined mismatches method

    DEFF Research Database (Denmark)

    Kamel, Salah; Jurado, Francisco; Chen, Zhe

    2016-01-01

    values are calculated during the iterative process based on the desired controlled values and buses voltage at the terminals of GUPFC. The parameters of GUPFC can be calculated during the iterative process and the final values are updated after load flow convergence. Using the developed GUPFC model......, the original structure and symmetry of the admittance and Jacobian matrices can still be kept, the changing of Jacobian matrix is eliminated. Consequently, the complexities of the computer load flow program codes with GUPFC are reduced. The HPCIM load flow code with the proposed model is written in C......++ programming language. Where, the SuperLU library is utilised to handle the sparse Jacobian matrix. The proposed model has been validated using the standard IEEE test systems....

  4. Investigation on premature occurrence of critical heat flux under oscillatory flow and power conditions

    International Nuclear Information System (INIS)

    Vishnoi, A.K.; Dasgupta, A.; Chandraker, D.K.; Nayak, A.K.; Vijayan, P.K.

    2015-01-01

    Two-phase natural circulation loops have extensive applications in nuclear and process industries. One of the major concerns with natural circulation is the occurrence of the various types of flow instabilities, which can cause premature boiling crisis due to flow and power oscillations. In this work a transient computer code COPCOS (Code for Prediction of CHF under Oscillating flow and power condition) has been developed to predict the premature occurrence of CHF (critical heat flux) under oscillating flow and power. The code incorporates conduction equation of the fuel and coolant energy equation. For CHF prediction, CHF look-up table developed by Groeneveld is used. A facility named CHF and Instability Loop (CHIL) has been set up to study the effect of oscillatory flow on CHF. CHF and Instability Loop (CHIL) is a simple rectangular loop having a 10.5 mm ID and 1.2 m long test section. The flow through the test section is controlled by a canned motor pump using a Variable Frequency Drive (VFD). This leads to the ability of having a very precise control over flow oscillations which can be induced in the test section. The effect of frequency and amplitude of flow oscillation on occurrence of premature CHF has been investigated in this facility using COPCOS. Full paper covers details of COPCOS code, description of the facility and effect of frequency and the effect of oscillatory flow on CHF in the facility. (author)

  5. Multilevel Flow Modeling for Nuclear Power Plant Diagnosis

    DEFF Research Database (Denmark)

    Gola, G; Lind, Morten; Thunem, Harald P-J

    2012-01-01

    , especially if extended to the whole plant. Monitoring plant performances by means of data reconciliation techniques has proved successful to detect anomalies during operation, provide early warnings and eventually schedule maintenance. At the same time, the large amount of information provided by large...... detected anomalies. The combination of a data reconciliation system and the Multilevel Flow Modeling approach is illustrated with regard to the secondary loop of the Loviisa-2 Pressurized Water Reactor located in Finland....

  6. PI2 controller based coordinated control with Redox Flow Battery and Unified Power Flow Controller for improved Restoration Indices in a deregulated power system

    Directory of Open Access Journals (Sweden)

    R. Thirunavukarasu

    2016-12-01

    Full Text Available The nature of power system restoration problem involves status assessment, optimization of generation capability and load pickup. This paper proposes the evaluation of Power System Restoration Indices (PSRI based on the Automatic Generation Control (AGC assessment of interconnected power system in a deregulated environment. The PSRI are useful for system planners to prepare the power system restoration plans and to improve the efficiency of the physical operation of the power system with the increased transmission capacity in the network. The stabilization of frequency and tie-line power oscillations in an interconnected power system becomes challenging when implemented in the future competitive environment. This paper also deals with the concept of AGC in two-area reheat power system having coordinated control action with Redox Flow Battery (RFB and Unified Power Flow Controller (UPFC are capable of controlling the network performance in a very fast manner and improve power transfer limits in order to have a better restoration. In addition to that a new Proportional–Double Integral (PI2 controller is designed and implemented in AGC loop and controller parameters are optimized through Bacterial Foraging Optimization (BFO algorithm. Simulation results reveal that the proposed PI2 controller is that it has good stability during load variations, excellent transient and dynamic responses when compared with the system comprising PI controller. Moreover the AGC loop with RFB coordinated with UPFC has greatly improved the dynamic response and it reduces the control input requirements, to ensure improved PSRI in order to provide the reduced restoration time, thereby improving the system reliability.

  7. Convex Relaxations of Chance Constrained AC Optimal Power Flow

    DEFF Research Database (Denmark)

    Venzke, Andreas; Halilbasic, Lejla; Markovic, Uros

    2017-01-01

    , reactive power, and voltage. We state a tractable formulation for two types of uncertainty sets. Using a scenario-based approach and making no prior assumptions about the probability distribution of the forecast errors, we obtain a robust formulation for a rectangular uncertainty set. Alternatively...

  8. A large deviation based splitting estimation of power flow reliability

    NARCIS (Netherlands)

    W.S. Wadman (Wander); D.T. Crommelin (Daan); A.P. Zwart (Bert)

    2016-01-01

    htmlabstractGiven the continued integration of intermittent renewable generators in electrical power grids, connection overloads are of increasing concern for grid operators. The risk of an overload due to injection variability can be described mathematically as a barrier crossing probability of a

  9. A Large Deviation based Splitting Estimation of Power Flow Reliability

    NARCIS (Netherlands)

    W.S. Wadman (Wander); D.T. Crommelin (Daan); A.P. Zwart (Bert)

    2016-01-01

    htmlabstractGiven the continued integration of intermittent renewable generators in electrical power grids, connection overloads are of increasing concern for grid operators. The risk of an overload due to injection variability can be described mathematically as a barrier crossing probability of a

  10. Mass transfer coefficient in disturbed flow due to orifice for flow accelerated corrosion in nuclear power plant

    International Nuclear Information System (INIS)

    Prasad, Mahendra; Gaikwad, Avinash J.; Sridharan, Arunkumar; Parida, Smrutiranjan

    2015-01-01

    The flow of fluid in pipes cause corrosion wherein the inner surface of pipe becomes progressively thinner and susceptible to failure. This form of corrosion dependent on flow dynamics is called Flow Accelerated Corrosion (FAC) and has been observed in Nuclear Power Plants (NPPs). Mass transfer coefficient (MTC) is related to extent of wall thinning and it changes from its value in a straight pipe (with same fluid parameters) for flow in orifices, bends, junctions etc. due to gross disturbance of the velocity profile. This paper presents two-dimensional computational fluid dynamics (CFD) simulations for an orifice configuration in a straight pipe. Turbulent model K- ω with shear stress transport and transition flow was the model used for simulation studies. The mass transfer boundary layer (MTBL) thickness δ mtbl is related to the Schmidt number (Sc) and hydrodynamic boundary layer thickness δ h , as δ mtbl ~ δh/(Sc 1/3 ). MTBL is significantly smaller than δ h and hence boundary layer meshing was carried out deep into δ mtbl . Uniform velocity profile was applied at the inlet. Post orifice fluid shows large recirculating flows on the upper and lower wall. At various locations after orifice, mass transfer coefficient is calculated and compared with the value in straight pipe with fully developed turbulent flow. The MTC due to the orifice increases and it is correlated with enhanced FAC in region after orifice. (author)

  11. Model-based Fuel Flow Control for Fossil-fired Power Plants

    DEFF Research Database (Denmark)

    Niemczyk, Piotr

    2010-01-01

    -fired power plants represent the largest reserve of such controllable power sources in several countries. However, their production take-up rates are limited, mainly due to poor fuel flow control. The thesis presents analysis of difficulties and potential improvements in the control of the coal grinding...

  12. Mathematical modeling for laminar flow of power law fluid in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Renato A.; Mesquita, Maximilian S. [Universidade Federal do Espirito Santo (UFES), Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Dept. de Engenharias e Computacao

    2010-07-01

    In this paper, the macroscopic equations for laminar power-law fluid flow is obtained for a porous medium starting from traditional equations (Navier-Stokes). Then, the volume averaging is applied in traditional transport equations with the power-law fluid model. This procedure leads to macroscopic transport equations set for non-Newtonian fluid. (author)

  13. Preventive Security-Constrained Optimal Power Flow Considering UPFC Control Modes

    Directory of Open Access Journals (Sweden)

    Xi Wu

    2017-08-01

    Full Text Available The successful application of the unified power flow controller (UPFC provides a new control method for the secure and economic operation of power system. In order to make the full use of UPFC and improve the economic efficiency and static security of a power system, a preventive security-constrained power flow optimization method considering UPFC control modes is proposed in this paper. Firstly, an iterative method considering UPFC control modes is deduced for power flow calculation. Taking into account the influence of different UPFC control modes on the distribution of power flow after N-1 contingency, the optimization model is then constructed by setting a minimal system operation cost and a maximum static security margin as the objective. Based on this model, the particle swarm optimization (PSO algorithm is utilized to optimize power system operating parameters and UPFC control modes simultaneously. Finally, a standard IEEE 30-bus system is utilized to demonstrate that the proposed method fully exploits the potential of static control of UPFC and significantly increases the economic efficiency and static security of the power system.

  14. A study on heat transfer enhancement using flow channel inserts for thermoelectric power generation

    International Nuclear Information System (INIS)

    Lesage, Frédéric J.; Sempels, Éric V.; Lalande-Bertrand, Nathaniel

    2013-01-01

    Highlights: • Thermal enhancement in a thermoelectric liquid generator is tested. • Thermal enhancement is brought upon by flow impeding inserts. • CFD simulations attribute thermal enhancement to velocity field alterations. • Thermoelectric power enhancement is measured and discussed. • Power enhancement relative to adverse pressure drop is investigated. - Abstract: Thermoelectric power production has many potential applications that range from microelectronics heat management to large scale industrial waste-heat recovery. A low thermoelectric conversion efficiency of the current state of the art prevents wide spread use of thermoelectric modules. The difficulties lie in material conversion efficiency, module design, and thermal system management. The present study investigates thermoelectric power improvement due to heat transfer enhancement at the channel walls of a liquid-to-liquid thermoelectric generator brought upon by flow turbulating inserts. Care is taken to measure the adverse pressure drop due to the presence of flow impeding obstacles in order to measure the net thermoelectric power enhancement relative to an absence of inserts. The results illustrate the power enhancement performance of three different geometric forms fitted into the channels of a thermoelectric generator. Spiral inserts are shown to offer a minimal improvement in thermoelectric power production whereas inserts with protruding panels are shown to be the most effective. Measurements of the thermal enhancement factor which represents the ratio of heat flux into heat flux out of a channel and numerical simulations of the internal flow velocity field attribute the thermal enhancement resulting in the thermoelectric power improvement to thermal and velocity field synergy

  15. Power and Flow Experience in Time-Intensive Business Simulation Game

    Science.gov (United States)

    Kiili, Kristian; Lainema, Timo

    2010-01-01

    Power is an influential component of social interaction and there are reasons for thinking that it may have important effects both on decision-making and psychological and interpersonal processes. The aim of this paper was to study the relations between the feeling of power, decision-making and flow experience in a collaborative business…

  16. Newton Power Flow Methods for Unbalanced Three-Phase Distribution Networks

    NARCIS (Netherlands)

    Sereeter, B.; Vuik, C.; Witteveen, C.

    2017-01-01

    Two mismatch functions (power or current) and three coordinates (polar, Cartesian andcomplex form) result in six versions of the Newton–Raphson method for the solution of powerflow problems. In this paper, five new versions of the Newton power flow method developed forsingle-phase problems in our

  17. Equivalent Method of Integrated Power Generation System of Wind, Photovoltaic and Energy Storage in Power Flow Calculation and Transient Simulation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The integrated power generation system of wind, photovoltaic (PV) and energy storage is composed of several wind turbines, PV units and energy storage units. The detailed model of integrated generation is not suitable for the large-scale powe.r system simulation because of the model's complexity and long computation time. An equivalent method for power flow calculation and transient simulation of the integrated generation system is proposed based on actual projects, so as to establish the foundation of such integrated system simulation and analysis.

  18. Regulation of Renewable Energy Sources to Optimal Power Flow Solutions Using ADMM: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yijian; Hong, Mingyi; Dall' Anese, Emiliano; Dhople, Sairaj; Xu, Zi

    2017-03-03

    This paper considers power distribution systems featuring renewable energy sources (RESs), and develops a distributed optimization method to steer the RES output powers to solutions of AC optimal power flow (OPF) problems. The design of the proposed method leverages suitable linear approximations of the AC-power flow equations, and is based on the Alternating Direction Method of Multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the OPF problem is established under suitable conditions on the stepsize as well as mismatches between the commanded setpoints and actual RES output powers. In a broad sense, the methods and results proposed here are also applicable to other distributed optimization problem setups with ADMM and inexact dual updates.

  19. A Novel Algorithm for Power Flow Transferring Identification Based on WAMS

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2015-01-01

    Full Text Available After a faulted transmission line is removed, power flow on it will be transferred to other lines in the network. If those lines are heavily loaded beforehand, the transferred flow may cause the nonfault overload and the incorrect operation of far-ranging backup relays, which are considered as the key factors leading to cascading trips. In this paper, a novel algorithm for power flow transferring identification based on wide area measurement system (WAMS is proposed, through which the possible incorrect tripping of backup relays will be blocked in time. A new concept of Transferred Flow Characteristic Ratio (TFCR is presented and is applied to the identification criteria. Mathematical derivation of TFCR is carried out in detail by utilization of power system short circuit fault modeling. The feasibility and effectiveness of the proposed algorithm to prevent the malfunction of backup relays are demonstrated by a large number of simulations.

  20. Power and color Doppler ultrasound settings for inflammatory flow

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Christensen, Robin; Szkudlarek, Marcin

    2015-01-01

    OBJECTIVE: To determine how settings for power and color Doppler ultrasound sensitivity vary on different high- and intermediate-range ultrasound machines and to evaluate the impact of these changes on Doppler scoring of inflamed joints. METHODS: Six different types of ultrasound machines were used....... On each machine, the factory setting for superficial musculoskeletal scanning was used unchanged for both color and power Doppler modalities. The settings were then adjusted for increased Doppler sensitivity, and these settings were designated study settings. Eleven patients with rheumatoid arthritis (RA......) with wrist involvement were scanned on the 6 machines, each with 4 settings, generating 264 Doppler images for scoring and color quantification. Doppler sensitivity was measured with a quantitative assessment of Doppler activity: color fraction. Higher color fraction indicated higher sensitivity. RESULTS...

  1. Framework for optimal power flow incorporating dynamic system security

    International Nuclear Information System (INIS)

    El-Kady, M.A.; Owayedh, M.S.

    2006-01-01

    This paper introduces a novel framework and methodologies which are capable of tackling the complex issue of power system economy versus security in a practical and effective manner. At heart of achieving such a challenging and far-reaching objective is the incorporation of the Dyanamic Security Assessment (DSA) into production optimization techniques using the Transient Energy Function (TEF) method. In addition, and in parallel with the already well established concept of the system security, two new concepts pertaining to power system performance will be introduced in this paper, namely the concept of system dynamic susceptibility, which measures the level of systems weakness to a particular contingency and the concept of system consequent restorability, which measures the extent of contingency severity in terms of the required subsequent system restoration work should a particular contingency occur. (author)

  2. On heat transfer of weakly compressible power-law flows

    Directory of Open Access Journals (Sweden)

    Li Botong

    2017-01-01

    Full Text Available This paper completes a numerical research on steady momentum and heat transfer in power-law fluids in a channel. Weakly compressible laminar fluids are studied with no slip at the walls and uniform wall temperatures. The full governing equations are solved by continuous finite element method. Three thermal conductivity models are adopted in this paper, that is, constant thermal conductivity model, thermal conductivity varying as a function of temperature gradient, and a modified temperature-gradient-dependent thermal conductivity model. The results are compared with each other and the physical characteristics for values of parameters are also discussed in details. It is shown that the velocity curve from the solution becomes straight at higher power-law index. The effects of Reynolds numbers on the dilatant fluid and the pseudo-plastic look similar to each other and their trends can be easily predicted. Furthermore, for different models, the temperature curves also present pseudo-plastic and dilatant properties.

  3. Advanced power flow technologies for high current ICF accelerators

    International Nuclear Information System (INIS)

    VanDevender, J.P.; McDaniel, D.H.

    1978-01-01

    Two new technologies for raising the power density in high current, inertial confinement fusion accelerators have been developed in the past two years. Magnetic flashover inhibition utilizes the self-magnetic fields around the vacuum insulator surface to inhibit surface flashover; average electric fields of 40 Mv/m at magnetic fields of 1.1 T have been achieved. Self-magnetic insulation of long, vacuum transmission lines has been used to transport power at 1.6 x 10 14 W/m 2 over six meters and up to 1.6 x 10 15 W/m 2 over short distances in a radial anode-cathode feed. The recent data relevant to these new technologies and their implications for ICF will be explored

  4. A solution to the optimal power flow using multi-verse optimizer

    Directory of Open Access Journals (Sweden)

    Bachir Bentouati

    2016-12-01

    Full Text Available In this work, the most common problem of the modern power system named optimal power flow (OPF is optimized using the novel meta-heuristic optimization Multi-verse Optimizer(MVO algorithm. In order to solve the optimal power flow problem, the IEEE 30-bus and IEEE 57-bus systems are used. MVO is applied to solve the proposed problem. The problems considered in the OPF problem are fuel cost reduction, voltage profile improvement, voltage stability enhancement. The obtained results are compared with recently published meta-heuristics. Simulation results clearly reveal the effectiveness and the rapidity of the proposed algorithm for solving the OPF problem.

  5. Optimal Power Flow Modelling and Analysis of Hybrid AC-DC Grids with Offshore Wind Power Plant

    DEFF Research Database (Denmark)

    Dhua, Debasish; Huang, Shaojun; Wu, Qiuwei

    2017-01-01

    In order to develop renewables based energy systems, the installation of the offshore wind power plants (WPPs) is globally encouraged. However, wind power generation is intermittent and uncertain. An accurate modelling and evaluation reduces investment and provide better operation. Hence......, the wind power production level also plays a major role in a hybrid system on transmission loss evaluation. The developed model is tested in Low, Medium and High wind power production levels to determine the objective function of the OPF solution. MATLAB Optimization Toolbox and MATLAB script are used......, it is essential to develop a suitable model and apply optimization algorithms for different application scenarios. The objective of this work is to develop a generalized model and evaluate the Optimal Power Flow (OPF) solutions in a hybrid AC/DC system including HVDC (LCC based) and offshore WPP (VSC based...

  6. A decomposition method for network-constrained unit commitment with AC power flow constraints

    International Nuclear Information System (INIS)

    Bai, Yang; Zhong, Haiwang; Xia, Qing; Kang, Chongqing; Xie, Le

    2015-01-01

    To meet the increasingly high requirement of smart grid operations, considering AC power flow constraints in the NCUC (network-constrained unit commitment) is of great significance in terms of both security and economy. This paper proposes a decomposition method to solve NCUC with AC power flow constraints. With conic approximations of the AC power flow equations, the master problem is formulated as a MISOCP (mixed integer second-order cone programming) model. The key advantage of this model is that the active power and reactive power are co-optimised, and the transmission losses are considered. With the AC optimal power flow model, the AC feasibility of the UC result of the master problem is checked in subproblems. If infeasibility is detected, feedback constraints are generated based on the sensitivity of bus voltages to a change in the unit reactive power generation. They are then introduced into the master problem in the next iteration until all AC violations are eliminated. A 6-bus system, a modified IEEE 30-bus system and the IEEE 118-bus system are used to validate the performance of the proposed method, which provides a satisfactory solution with approximately 44-fold greater computational efficiency. - Highlights: • A decomposition method is proposed to solve the NCUC with AC power flow constraints • The master problem considers active power, reactive power and transmission losses. • OPF-based subproblems check the AC feasibility using parallel computing techniques. • An effective feedback constraint interacts between the master problem and subproblem. • Computational efficiency is significantly improved with satisfactory accuracy

  7. Optimized Reactive Power Flow of DFIG Power Converters for Better Reliability Performance Considering Grid Codes

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, Mogens

    2015-01-01

    . In order to fulfill the modern grid codes, over-excited reactive power injection will further reduce the lifetime of the rotor-side converter. In this paper, the additional stress of the power semiconductor due to the reactive power injection is firstly evaluated in terms of modulation index...

  8. A low-power high-flow shape memory alloy wire gas microvalve

    International Nuclear Information System (INIS)

    Gradin, Henrik; Braun, Stefan; Stemme, Göran; Van der Wijngaart, Wouter; Clausi, Donato; Peirs, Jan; Reynaerts, Dominiek

    2012-01-01

    In this paper the use of shape memory alloy (SMA) wire actuators for high gas flow control is investigated. A theoretical model for effective gas flow control is presented and gate microvalve prototypes are fabricated. The SMA wire actuator demonstrates the robust flow control of more than 1600 sccm at a pressure drop of 200 kPa. The valve can be successfully switched at over 10 Hz and at an actuation power of 90 mW. Compared to the current state-of-the-art high-flow microvalves, the proposed solution benefits from a low-voltage actuator with low overall power consumption. This paper demonstrate that SMA wire actuators are well suited for high-pressurehigh-flow applications. (paper)

  9. Distribution-Agnostic Stochastic Optimal Power Flow for Distribution Grids: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Kyri; Dall' Anese, Emiliano; Summers, Tyler

    2016-09-01

    This paper outlines a data-driven, distributionally robust approach to solve chance-constrained AC optimal power flow problems in distribution networks. Uncertain forecasts for loads and power generated by photovoltaic (PV) systems are considered, with the goal of minimizing PV curtailment while meeting power flow and voltage regulation constraints. A data- driven approach is utilized to develop a distributionally robust conservative convex approximation of the chance-constraints; particularly, the mean and covariance matrix of the forecast errors are updated online, and leveraged to enforce voltage regulation with predetermined probability via Chebyshev-based bounds. By combining an accurate linear approximation of the AC power flow equations with the distributionally robust chance constraint reformulation, the resulting optimization problem becomes convex and computationally tractable.

  10. Optimal power flow for technically feasible Energy Management systems in Islanded Microgrids

    DEFF Research Database (Denmark)

    Sanseverino, Eleonora Riva; T. T. Quynh, T.; Di Silvestre, Maria Luisa

    2016-01-01

    This paper presents a combined optimal energy and power flow management for islanded microgrids. The highest control level in this case will provide a feasible and optimized operating point around the economic optimum. In order to account for both unbalanced and balanced loads, the optimal power...... flow is carried out using a Glow-worm Swarm Optimizer. The control level is organized into two different sub-levels, the highest of which accounts for minimum cost operation and the lowest one solving the optimal power flow and devising the set points of inverter interfaced generation units...... and rotating machines with a minimum power loss. A test has been carried out for 6 bus islanded microgrids to show the efficiency and feasibility of the proposed technique....

  11. Optimal Power Flow by Interior Point and Non Interior Point Modern Optimization Algorithms

    Directory of Open Access Journals (Sweden)

    Marcin Połomski

    2013-03-01

    Full Text Available The idea of optimal power flow (OPF is to determine the optimal settings for control variables while respecting various constraints, and in general it is related to power system operational and planning optimization problems. A vast number of optimization methods have been applied to solve the OPF problem, but their performance is highly dependent on the size of a power system being optimized. The development of the OPF recently has tracked significant progress both in numerical optimization techniques and computer techniques application. In recent years, application of interior point methods to solve OPF problem has been paid great attention. This is due to the fact that IP methods are among the fastest algorithms, well suited to solve large-scale nonlinear optimization problems. This paper presents the primal-dual interior point method based optimal power flow algorithm and new variant of the non interior point method algorithm with application to optimal power flow problem. Described algorithms were implemented in custom software. The experiments show the usefulness of computational software and implemented algorithms for solving the optimal power flow problem, including the system model sizes comparable to the size of the National Power System.

  12. Nonlinear Power Flow Control Design Utilizing Exergy, Entropy, Static and Dynamic Stability, and Lyapunov Analysis

    CERN Document Server

    Robinett III, Rush D

    2011-01-01

    Nonlinear Powerflow Control Design presents an innovative control system design process motivated by renewable energy electric grid integration problems. The concepts developed result from the convergence of three research and development goals: • to create a unifying metric to compare the value of different energy sources – coal-burning power plant, wind turbines, solar photovoltaics, etc. – to be integrated into the electric power grid and to replace the typical metric of costs/profit; • to develop a new nonlinear control tool that applies power flow control, thermodynamics, and complex adaptive systems theory to the energy grid in a consistent way; and • to apply collective robotics theories to the creation of high-performance teams of people and key individuals in order to account for human factors in controlling and selling power into a distributed, decentralized electric power grid. All three of these goals have important concepts in common: exergy flow, limit cycles, and balance between compe...

  13. Integrated Power Flow and Short Circuit Calculation Method for Distribution Network with Inverter Based Distributed Generation

    Directory of Open Access Journals (Sweden)

    Shan Yang

    2016-01-01

    Full Text Available Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverter based distributed generation is proposed. The proposed method let the inverter based distributed generation be equivalent to Iθ bus, which makes it suitable to calculate the power flow of distribution network with a current limited inverter based distributed generation. And the low voltage ride through capability of inverter based distributed generation can be considered as well in this paper. Finally, some tests of power flow and short circuit current calculation are performed on a 33-bus distribution network. The calculated results from the proposed method in this paper are contrasted with those by the traditional method and the simulation method, whose results have verified the effectiveness of the integrated method suggested in this paper.

  14. Feasibility Study of Power Uprate Using Ultrasonic Flow Meters in NPPs

    International Nuclear Information System (INIS)

    Kim, Tae Mi; Heo, Gyun Young

    2010-01-01

    Feedwater flowrate is an important input parameter in establishing the plant's operating power level. In Korean nuclear power plants, venturi flow meters have been used for measuring the feedwater flow of the secondary side. However, as time goes on, the fouling in venture meters could cause measurement uncertainties to grow and that could lead to operation at less than about 2% of the licensed thermal power limit. In order to resolve the problem, nuclear power plants in other countries use Ultrasonic Flow Meters (UFMs) which have relatively lower measurement uncertainty (about 0.5%) instead of venturi flow meters and have reduced the errors from the fouling in venturi-type flow meters. USA amended 10 CFR 50 Appendix K so that US nuclear power plants can use real value of Core Operating Limit Supervisory System (COLSS) uncertainty, which is currently fixed as 2%, by adopting the UFM. Korea also has been amended the law in order to get benefits from the technology. In this study, we are going to present the fundamental principles of UFMs and the advantages and disadvantages of its installation. Also, we inquire into the conventional uses of UFMs in the overseas sites and then check what is needed to consider for its domestic application

  15. Incorporation of a Wind Generator Model into a Dynamic Power Flow Analysis

    Directory of Open Access Journals (Sweden)

    Angeles-Camacho C.

    2011-07-01

    Full Text Available Wind energy is nowadays one of the most cost-effective and practical options for electric generation from renewable resources. However, increased penetration of wind generation causes the power networks to be more depend on, and vulnerable to, the varying wind speed. Modeling is a tool which can provide valuable information about the interaction between wind farms and the power network to which they are connected. This paper develops a realistic characterization of a wind generator. The wind generator model is incorporated into an algorithm to investigate its contribution to the stability of the power network in the time domain. The tool obtained is termed dynamic power flow. The wind generator model takes on account the wind speed and the reactive power consumption by induction generators. Dynamic power flow analysis is carried-out using real wind data at 10-minute time intervals collected for one meteorological station. The generation injected at one point into the network provides active power locally and is found to reduce global power losses. However, the power supplied is time-varying and causes fluctuations in voltage magnitude and power fl ows in transmission lines.

  16. Power Flow Simulations of a More Renewable California Grid Utilizing Wind and Solar Insolation Forecasting

    Science.gov (United States)

    Hart, E. K.; Jacobson, M. Z.; Dvorak, M. J.

    2008-12-01

    Time series power flow analyses of the California electricity grid are performed with extensive addition of intermittent renewable power. The study focuses on the effects of replacing non-renewable and imported (out-of-state) electricity with wind and solar power on the reliability of the transmission grid. Simulations are performed for specific days chosen throughout the year to capture seasonal fluctuations in load, wind, and insolation. Wind farm expansions and new wind farms are proposed based on regional wind resources and time-dependent wind power output is calculated using a meteorological model and the power curves of specific wind turbines. Solar power is incorporated both as centralized and distributed generation. Concentrating solar thermal plants are modeled using local insolation data and the efficiencies of pre-existing plants. Distributed generation from rooftop PV systems is included using regional insolation data, efficiencies of common PV systems, and census data. The additional power output of these technologies offsets power from large natural gas plants and is balanced for the purposes of load matching largely with hydroelectric power and by curtailment when necessary. A quantitative analysis of the effects of this significant shift in the electricity portfolio of the state of California on power availability and transmission line congestion, using a transmission load-flow model, is presented. A sensitivity analysis is also performed to determine the effects of forecasting errors in wind and insolation on load-matching and transmission line congestion.

  17. Three-phase Power Flow Calculation of Low Voltage Distribution Network Considering Characteristics of Residents Load

    Science.gov (United States)

    Wang, Yaping; Lin, Shunjiang; Yang, Zhibin

    2017-05-01

    In the traditional three-phase power flow calculation of the low voltage distribution network, the load model is described as constant power. Since this model cannot reflect the characteristics of actual loads, the result of the traditional calculation is always different from the actual situation. In this paper, the load model in which dynamic load represented by air conditioners parallel with static load represented by lighting loads is used to describe characteristics of residents load, and the three-phase power flow calculation model is proposed. The power flow calculation model includes the power balance equations of three-phase (A,B,C), the current balance equations of phase 0, and the torque balancing equations of induction motors in air conditioners. And then an alternating iterative algorithm of induction motor torque balance equations with each node balance equations is proposed to solve the three-phase power flow model. This method is applied to an actual low voltage distribution network of residents load, and by the calculation of three different operating states of air conditioners, the result demonstrates the effectiveness of the proposed model and the algorithm.

  18. A heuristic technique to determine corrective control actions for reactive power flows

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, Angel L.; Martinez, Jose L.; Riquelme, Jesus; Romero, Esther [Department of Electrical Engineering, University of Sevilla (Spain)

    2011-01-15

    This paper presents a sensitivity-based heuristic tool designed to help the system operator in the reactive power flow control problem. The objective of the proposed technique is to determine control actions to ensure that reactive power flows in transmission-subtransmission boundary transformers remain within specified limits, satisfying the new regulatory constraints imposed in most of deregulated markets. With this new constraint the utilities want to guarantee that the utility is able to satisfy its own reactive power requirements, avoiding reactive power flows through long distances in order to reduce the well known disadvantages that reactive power circulation has in the system. A 5-bus tutorial system is used to present the proposed algorithm. The results of the application of the proposed technique to the IEEE 118 buses system and to a regional subtransmission network of the South of Spain are reported and analyzed. In this last actual case, the aim is to maintain reactive power flows in transmission/distribution transformers between those limits set by the Spanish Regulation. A comparison between the proposed tool and a conventional OPF is discussed. (author)

  19. Power Flow Control through a Multi-Level H-Bridge-based Power Converter for Universal and Flexible Power Management in Future Electrical Grids

    DEFF Research Database (Denmark)

    Iov, Florin; Bifaretti, Steffano; Zanchetta, Pericle

    2008-01-01

    The paper proposes a novel power conversion system for Universal and Flexible Power Management (UNIFLEX-PM) in Future Electricity Network. The structure is based on three AC-DC converters each one connected to a different grid, (representing the main grid and/or various distributed generation...... systems) on the AC side, and linked together at DC side by suitable DC isolation modules. Each port of the UNIFLEX-PM system employs a conversion structure based on a three-phase 7-level AC-DC cascaded converter. Effective and accurate power flow control is demonstrated through simulation in Matlab...... and Simulink environment on a simplified model based on a two-port structure and using a Stationery Reference Frame based control solution. Control of different Power flow profiles has been successfully tested in numerous network conditions such as voltage unbalance, frequency excursions and harmonic...

  20. Assessment of Power Potential of Tidal Currents and Impacts of Power Extraction on Flow Conditions in Indonesia

    Science.gov (United States)

    Orhan, Kadir; Mayerle, Roberto

    2017-04-01

    Climate change is an urgent and potentially irreversible threat to human societies and the planet and thus requires an effective and appropriate response, with a view to accelerating the reduction of global greenhouse gas emissions. At this point, a worldwide shift to renewable energy is crucial. In this study, a methodology comprising of the estimates of power yield, evaluation of the effects of power extraction on flow conditions, and near-field investigations to deliver wake characteristics, recovery and interactions is described and applied to several straits in Indonesia. Site selection is done with high-resolution, three-dimensional flow models providing sufficient spatiotemporal coverage. Much attention has been given to the meteorological forcing, and conditions at the open sea boundaries to adequately capture the density gradients and flow fields. Model verifications using tidal records show excellent agreement. Sites with adequate depth for the energy conversion using horizontal axis tidal turbines, average kinetic power density greater than 0.5 kW/m2, and surface area larger than 0.5km2 are defined as energy hotspots. Spatial variation of the average extractable electric power is determined, and annual tidal energy resource is estimated for the straits in question. The results showed that the potential for tidal power generation in Indonesia is likely to exceed previous predictions reaching around 4,800MW. Models with higher resolutions have been developed to assess the impacts of devices on flow conditions and to resolve near-field turbine wakes in greater detail. The energy is assumed to be removed uniformly by sub-grid scale arrays of turbines. An additional drag force resulting in dissipation of the pre-existing kinetic power from 10% to 60% within a flow cross-section is introduced to capture the impacts. k-ɛ model, which is a second order turbulence closure model is selected to involve the effects of the turbulent kinetic energy and turbulent

  1. Network fault response of wind power plants in distribution systems during reverse power flows. Part II

    NARCIS (Netherlands)

    Boemer, J.C.; Gibescu, M.; vd Meijden, M.A.M.M.; Rawn, B.G.; Kling, W.L.

    2013-01-01

    Abstract—The ability of wind power park modules to control their response to transmission network faults allows for specification of new control features directed at stabilising the power system response during and after disturbances. However, the ‘effectiveness’ of these features in situations

  2. Multi-objective optimal reactive power dispatch to maximize power system social welfare in the presence of generalized unified power flow controller

    Directory of Open Access Journals (Sweden)

    Suresh Chintalapudi Venkata

    2015-09-01

    Full Text Available In this paper a novel non-linear optimization problem is formulated to maximize the social welfare in restructured environment with generalized unified power flow controller (GUPFC. This paper presents a methodology to optimally allocate the reactive power by minimizing voltage deviation at load buses and total transmission power losses so as to maximize the social welfare. The conventional active power generation cost function is modified by combining costs of reactive power generated by the generators, shunt capacitors and total power losses to it. The formulated objectives are optimized individually and simultaneously as multi-objective optimization problem, while satisfying equality, in-equality, practical and device operational constraints. A new optimization method, based on two stage initialization and random distribution processes is proposed to test the effectiveness of the proposed approach on IEEE-30 bus system, and the detailed analysis is carried out.

  3. State powers and responsibilities concerning the flow of waste

    International Nuclear Information System (INIS)

    Snyder, Patrick M.; Monaco, Cindy M.

    1992-01-01

    The primary source of federal jurisdiction over the transportation and management of waste is derived from the Commerce Clause of the U.S. Constitution. That authority is of two main types - active, which empowers federal supervision over matters affecting commerce, and passive, which restrains state activity regarding commerce-related issues. The passive, or dormant, powers prevent a state from undertaking economic protectionist actions, but they do not prevent legitimate regulation for public health and safety where there is not a less intrusive alternative. The Commerce Clause does not prohibit states from making market-based decisions as proprietors, and discriminatory activities may be undertaken in that capacity. A federally approved compact empowers states or groups of states to act in ways that would otherwise be precluded by the Commerce Clause. The public policy issues at work in the above situations are discussed. Several proposals to revise the Low-Level Radioactive Waste Policy Amendments Act to conform with these principles are described. (author)

  4. Two-phase flow in porous media: power-law scaling of effective permeability

    Energy Technology Data Exchange (ETDEWEB)

    Groeva, Morten; Hansen, Alex, E-mail: Morten.Grova@ntnu.no, E-mail: Alex.Hansen@ntnu.no [Department of Physics, NTNU, NO-7491 Trondheim (Norway)

    2011-09-15

    A recent experiment has reported power-law scaling of effective permeability of two-phase flow with respect to capillary number for a two-dimensional model porous medium. In this paper, we consider the simultaneous flow of two phases through a porous medium under steady-state conditions, fixed total flow-rate and saturation, using a two-dimensional network simulator. We obtain power-law exponents for the scaling of effective permeability with respect to capillary number. The simulations are performed both for viscosity matched fluids and for a high viscosity ratio resembling that of air and water. Good power-law behaviour is found for both cases. Different exponents are found, depending on saturation.

  5. Pump and Flow Control Subassembly of Thermal Control Subsystem for Photovoltaic Power Module

    Science.gov (United States)

    Motil, Brian; Santen, Mark A.

    1993-01-01

    The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.

  6. Power flow analysis for islanded microgrid in hierarchical structure of control system using optimal control theory

    Directory of Open Access Journals (Sweden)

    Thang Diep Thanh

    2017-12-01

    Full Text Available In environmental uncertainties, the power flow problem in islanded microgrid (MG becomes complex and non-trivial. The optimal power flow (OPL problem is described in this paper by using the energy balance between the power generation and load demand. The paper also presents the hierarchical control structure which consists of primary, secondary, tertiary, and emergency controls. Clearly, optimal power flow (OPL which implements a distributed tertiary control in hierarchical control. MG consists of diesel engine generator (DEG, wind turbine generator (WTG, and photovoltaic (PV power. In the control system considered, operation planning is realized based on profiles such that the MG, load, wind and photovoltaic power must be forecasted in short-period, meanwhile the dispatch source (i.e., DEG needs to be scheduled. The aim of the control problem is to find the dispatch output power by minimizing the total cost of energy that leads to the Hamilton-Jacobi-Bellman equation. Experimental results are presented, showing the effectiveness of optimal control such that the generation allows demand profile.

  7. Unconventional Coal in Wyoming: IGCC and Gasification of Direct Coal Liquefaction Residue

    Science.gov (United States)

    Schaffers, William Clemens

    Two unconventional uses for Wyoming Powder River Basin coal were investigated in this study. The first was the use of coal fired integrated gasification combined cycle (IGCC) plants to generate electricity. Twenty-eight different scenarios were modeled using AspenPlusRTM software. These included slurry, mechanical and dried fed gasifiers; Wyodak and Green River coals, 0%, 70%, and 90% CO2 capture; and conventional evaporative vs air cooling. All of the models were constructed on a feed basis of 6,900 tons of coal per day on an "as received basis". The AspenPlus RTM results were then used to create economic models using Microsoft RTM Excel for each configuration. These models assumed a 3 year construction period and a 30 year plant life. Results for capital and operating costs, yearly income, and internal rates of return (IRR) were compared. In addition, the scenarios were evaluated to compare electricity sales prices required to obtain a 12% IRR and to determine the effects of a carbon emissions tax on the sales price. The second part of the study investigated the gasification potential of residue remaining from solvent extraction or liquefaction of Powder River Basin Coal. Coal samples from the Decker mine on the Wyoming-Montana border were extracted with tetralin at a temperature of 360°C and pressure of 250 psi. Residue from the extraction was gasified with CO2 or steam at 833°C, 900°C and 975°C at pressures of 0.1 and 0.4 MPa. Product gases were analyzed with a mass spectrometer. Results were used to determine activation energies, reaction order, reaction rates and diffusion effects. Surface area and electron microscopic analyses were also performed on char produced from the solvent extraction residue.

  8. Hydraulic Bureaucracies and the Hydraulic Mission: Flows of Water, Flows of Power

    NARCIS (Netherlands)

    Molle, F.; Mollinga, P.P.; Wester, P.

    2009-01-01

    Anchored in 19th century scientism and an ideology of the domination of nature, inspired by colonial hydraulic feats, and fuelled by technological improvements in high dam constructions and power generation and transmission, large-scale water resources development has been a defining feature of the

  9. Stochastic Dynamic AC Optimal Power Flow Based on a Multivariate Short-Term Wind Power Scenario Forecasting Model

    Directory of Open Access Journals (Sweden)

    Wenlei Bai

    2017-12-01

    Full Text Available The deterministic methods generally used to solve DC optimal power flow (OPF do not fully capture the uncertainty information in wind power, and thus their solutions could be suboptimal. However, the stochastic dynamic AC OPF problem can be used to find an optimal solution by fully capturing the uncertainty information of wind power. That uncertainty information of future wind power can be well represented by the short-term future wind power scenarios that are forecasted using the generalized dynamic factor model (GDFM—a novel multivariate statistical wind power forecasting model. Furthermore, the GDFM can accurately represent the spatial and temporal correlations among wind farms through the multivariate stochastic process. Fully capturing the uncertainty information in the spatially and temporally correlated GDFM scenarios can lead to a better AC OPF solution under a high penetration level of wind power. Since the GDFM is a factor analysis based model, the computational time can also be reduced. In order to further reduce the computational time, a modified artificial bee colony (ABC algorithm is used to solve the AC OPF problem based on the GDFM forecasting scenarios. Using the modified ABC algorithm based on the GDFM forecasting scenarios has resulted in better AC OPF’ solutions on an IEEE 118-bus system at every hour for 24 h.

  10. DC Voltage Droop Control Implementation in the AC/DC Power Flow Algorithm: Combinational Approach

    DEFF Research Database (Denmark)

    Akhter, F.; Macpherson, D.E.; Harrison, G.P.

    2015-01-01

    of operational flexibility, as more than one VSC station controls the DC link voltage of the MTDC system. This model enables the study of the effects of DC droop control on the power flows of the combined AC/DC system for steady state studies after VSC station outages or transient conditions without needing...... to use its complete dynamic model. Further, the proposed approach can be extended to include multiple AC and DC grids for combined AC/DC power flow analysis. The algorithm is implemented by modifying the MATPOWER based MATACDC program and the results shows that the algorithm works efficiently....

  11. Numerical simulation of heat transfer in power law fluid flow through a stenosed artery

    Science.gov (United States)

    Talib, Amira Husni; Abdullah, Ilyani

    2017-11-01

    A numerical study of heat transfer in a power law fluid is investigated in this paper. The blood flow is treated as power law fluid with a presence of cosine shaped stenosis. This study reveals the effect of stenosis on the heat transfer and velocity of blood flowing in the constricted artery. The governing and energy equations are formulated in a cylindrical coordinate system. Hence, the set of equations and boundary conditions are solved numerically by Marker and Cell (MAC) method. The graphical result shows the profile of blood temperature is increased while the blood velocity is decreased at the critical height of stenosis.

  12. On power flow suppression in straight elastic pipes by use of equally spaced eccentric inertial attachments

    DEFF Research Database (Denmark)

    Sorokin, Sergey; Holst-Jensen, Ole

    2012-01-01

    The paper addresses the power flow suppression in an elastic beam of the tubular cross section (a pipe) at relatively low excitation frequencies by deploying a small number of equally spaced inertial attachments. The methodology of boundary integral equations is used to obtain an exact solution...... of the problem in vibrations of this structure. The power flow analysis in a pipe with and without equally spaced eccentric inertial attachments is performed and the effect of suppression of the energy transmission is demonstrated theoretically. These results are put in the context of predictions from...

  13. Effects of energetic coherent motions on the power and wake of an axial-flow turbine

    Science.gov (United States)

    Chamorro, L. P.; Hill, C.; Neary, V. S.; Gunawan, B.; Arndt, R. E. A.; Sotiropoulos, F.

    2015-05-01

    A laboratory experiment examined the effects of energetic coherent motions on the structure of the wake and power fluctuations generated by a model axial-flow hydrokinetic turbine. The model turbine was placed in an open-channel flow and operated under subcritical conditions. The incoming flow was locally perturbed with vertically oriented cylinders of various diameters. An array of three acoustic Doppler velocimeters aligned in the cross-stream direction and a torque transducer were used to collect high-resolution and synchronous measurements of the three-velocity components of the incoming and wake flow as well as the turbine power. A strong scale-to-scale interaction between the large-scale and broadband turbulence shed by the cylinders and the turbine power revealed how the turbulence structure modulates the turbine behavior. In particular, the response of the turbine to the distinctive von Kármán-type vortices shed from the cylinders highlighted this phenomenon. The mean and fluctuating characteristics of the turbine wake are shown to be very sensitive to the energetic motions present in the flow. Tip vortices were substantially dampened and the near-field mean wake recovery accelerated in the presence of energetic motions in the flow. Strong coherent motions are shown to be more effective than turbulence levels for triggering the break-up of the spiral structure of the tip-vortices.

  14. A numerical study on an optimum design of a Cross-flow type Power Turbine (CPT)

    International Nuclear Information System (INIS)

    Ha, Jin Ho; Kim, Chul Ho

    2008-01-01

    A wind turbine is one of the most popular energy conversion systems to generate electricity from the natural renewable energy source and an axial-flow type wind turbine is commonly used system for the generation electricity in the wind farm nowadays. In this study, a cross-flow type turbine has been studied for the application of wind turbine for electricity generation. The target capacity of the electric power generation of the model wind turbine developing in this project is 12volts-150A/H(about 1.8Kw). The important design parameters of the model turbine impeller are the inlet and exit angle of the turbine blade, number of blade, hub/tip ratio and exit flow angle of the housing. In this study, the radial equilibrium theorem was used to decide the inlet and exit angle of the model impeller blade and CFD technique was incorporated to have performance analysis of the design model power turbine for the optimum design of the geometry of the Cross-flow Power Turbine impeller and Casing. In CFD, Navier-Stokes equation is solved with the SIMPLEC method in a general coordinates system. Realizable k-ε turbulent model with MARS scheme was used for evaluating torque of each blade in the Cross-flow Power Turbine (CPT). From the result, the designed CPT with 24 impeller blades at α=40 .deg. and β=85 .deg. of turbine blade angle was estimated to generate 1.2Nm of the indicated torque and 200watts of the indicated power. On the basis of the rules of similarity, the generating power capacity of the real size CPT that is eight times longer than the model impeller is predicted to have an 1.6kW of the output power (about 12V-130A/H or 24V-65A/H)

  15. Thermal Flow and Structure Stability Analyses of High Power Waterload for 2450 MHz microwave applications

    International Nuclear Information System (INIS)

    Seon, S. W.; Kim, H. J.; Wang, S. J.; Kim, J. N.

    2016-01-01

    This study is focused on analyzing the internal flow dynamics in the waterload by changing the inlet and outlet locations and adding guide pipeline to the inlet. The internal flow field simulation is done with CFX tool to compare the water flow velocity and temperature distributions in the waterload. The waterload absorbs RF power, converts it to thermal power, and increases the water temperature so that heat could be quickly removed by the water injection. And it is installed on the end of transmission line and is used to absorb reflected RF power. High power waterload with cone-shaped quartz is designed for 10-30 kW power handling at 2450 MHz microwave system. The thermal flow and structural stability analysis for the 2450 MHz waterload is done using ANSYS and the results are presented in this work. Relocation of the inlet and addition of the guide pipeline in the simulation shows a decrease in the localized maximum water temperature and increased water velocity around the heat source. It is also shown that the modified waterload is structurally more stable

  16. Thermal Flow and Structure Stability Analyses of High Power Waterload for 2450 MHz microwave applications

    Energy Technology Data Exchange (ETDEWEB)

    Seon, S. W.; Kim, H. J.; Wang, S. J. [National Fusion Research Institute, Daejeon (Korea, Republic of); Kim, J. N. [KRF, Anyang (Korea, Republic of)

    2016-05-15

    This study is focused on analyzing the internal flow dynamics in the waterload by changing the inlet and outlet locations and adding guide pipeline to the inlet. The internal flow field simulation is done with CFX tool to compare the water flow velocity and temperature distributions in the waterload. The waterload absorbs RF power, converts it to thermal power, and increases the water temperature so that heat could be quickly removed by the water injection. And it is installed on the end of transmission line and is used to absorb reflected RF power. High power waterload with cone-shaped quartz is designed for 10-30 kW power handling at 2450 MHz microwave system. The thermal flow and structural stability analysis for the 2450 MHz waterload is done using ANSYS and the results are presented in this work. Relocation of the inlet and addition of the guide pipeline in the simulation shows a decrease in the localized maximum water temperature and increased water velocity around the heat source. It is also shown that the modified waterload is structurally more stable.

  17. Work flow management systems applied in nuclear power plants management system to a new computer platform

    International Nuclear Information System (INIS)

    Rodriguez Lorite, M.; Martin Lopez-Suevos, C.

    1996-01-01

    Activities performed in most companies are based on the flow of information between their different departments and personnel. Most of this information is on paper (delivery notes, invoices, reports, etc). The percentage of information transmitted electronically (electronic transactions, spread sheets, files from word processors, etc) is usually low. The implementation of systems to control and speed up this work flow is the aim of work flow management systems. This article presents a prototype for applying work flow management systems to a specific area: the basic life cycle of a purchase order in a nuclear power plant, which requires the involvement of various computer applications: purchase order management, warehouse management, accounting, etc. Once implemented, work flow management systems allow optimisation of the execution of different tasks included in the managed life cycles and provide parameters to, if necessary, control work cycles, allowing their temporary or definitive modification. (Author)

  18. Prediction of critical flow rates through power-operated relief valves

    International Nuclear Information System (INIS)

    Abdollahian, D.; Singh, A.

    1983-01-01

    Existing single-phase and two-phase critical flow models are used to predict the flow rates through the power-operated relief valves tested in the EPRI Safety and Relief Valve test program. For liquid upstream conditions, Homogeneous Equilibrium Model, Moody, Henry-Fauske and Burnell two-phase critical flow models are used for comparison with data. Under steam upstream conditions, the flow rates are predicted either by the single-phase isentropic equations or the Homogeneous Equilibrium Model, depending on the thermodynamic condition of the fluid at the choking plane. The results of the comparisons are used to specify discharge coefficients for different valves under steam and liquid upstream conditions and evaluate the existing approximate critical flow relations for a wide range of subcooled water and steam conditions

  19. Using Free Flow Energy Cumulation in Wind and Hydro Power Production

    Directory of Open Access Journals (Sweden)

    Lev Ktitorov

    2016-09-01

    Full Text Available When approaching a conventional wind turbine, the air flow is slowed down and widened. This results in a loss of turbine efficiency. In order to exploit wind or water flow power as effectively as possible, it was suggested that the turbine should be placed inside a shroud, which consists of 4 wing-shaped surfaces. Two internal airfoils improve the turbine performance by speeding up the flow acting on the turbine blades, two external wings create a field of low pressure behind the turbine, thus, helping to draw more mass flow to the turbine and avoid the loss of efficiency due to flow deceleration.  The system accumulates kinetic energy of the flow in a small volume where the smaller (and, therefore, cheaper turbine can be installed. A smaller system can be installed inside the bigger one, which would help to accumulate even more kinetic energy on the turbine. We call this method the kinetic energy summation with local flow redistribution. Both experiments and CFD simulations demonstrate a significant increase in velocity and generated mechanical power in comparison of those for a bare turbine.

  20. Deformation of a Capsule in a Power-Law Shear Flow

    Directory of Open Access Journals (Sweden)

    Fang-Bao Tian

    2016-01-01

    Full Text Available An immersed boundary-lattice Boltzmann method is developed for fluid-structure interactions involving non-Newtonian fluids (e.g., power-law fluid. In this method, the flexible structure (e.g., capsule dynamics and the fluid dynamics are coupled by using the immersed boundary method. The incompressible viscous power-law fluid motion is obtained by solving the lattice Boltzmann equation. The non-Newtonian rheology is achieved by using a shear rate-dependant relaxation time in the lattice Boltzmann method. The non-Newtonian flow solver is then validated by considering a power-law flow in a straight channel which is one of the benchmark problems to validate an in-house solver. The numerical results present a good agreement with the analytical solutions for various values of power-law index. Finally, we apply this method to study the deformation of a capsule in a power-law shear flow by varying the Reynolds number from 0.025 to 0.1, dimensionless shear rate from 0.004 to 0.1, and power-law index from 0.2 to 1.8. It is found that the deformation of the capsule increases with the power-law index for different Reynolds numbers and nondimensional shear rates. In addition, the Reynolds number does not have significant effect on the capsule deformation in the flow regime considered. Moreover, the power-law index effect is stronger for larger dimensionless shear rate compared to smaller values.

  1. Flow-driven triboelectric generator for directly powering a wireless sensor node.

    Science.gov (United States)

    Wang, Shuhua; Mu, Xiaojing; Yang, Ya; Sun, Chengliang; Gu, Alex Yuandong; Wang, Zhong Lin

    2015-01-14

    A triboelectric generator (TEG) for scavenging flow-driven mechanical -energy to directly power a wireless sensor node is demonstrated for the first time. The output performances of TEGs with different dimensions are systematically investigated, indicating that a largest output power of about 3.7 mW for one TEG can be achieved under an external load of 3 MΩ. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Hydraulic Bureaucracies and the Hydraulic Mission: Flows of Water, Flows of Power

    Directory of Open Access Journals (Sweden)

    François Molle

    2009-10-01

    Full Text Available Anchored in 19th century scientism and an ideology of the domination of nature, inspired by colonial hydraulic feats, and fuelled by technological improvements in high dam constructions and power generation and transmission, large-scale water resources development has been a defining feature of the 20th century. Whether out of a need to increase food production, raise rural incomes, or strengthen state building and the legitimacy of the state, governments – North and South, East and West – embraced the 'hydraulic mission' and entrusted it to powerful state water bureaucracies (hydrocracies. Engaged in the pursuit of iconic and symbolic projects, the massive damming of river systems, and the expansion of large-scale public irrigation these hydrocracies have long remained out of reach. While they have enormously contributed to actual welfare, including energy and food generation, flood protection and water supply to urban areas, infrastructural development has often become an end in itself, rather than a means to an end, fuelling rent-seeking and symbolising state power. In many places projects have been challenged on the basis of their economic, social or environmental impacts. Water bureaucracies have been challenged internally (within the state bureaucracies or through political changes and externally (by critiques from civil society and academia, or by reduced funding. They have endeavoured to respond to these challenges by reinventing themselves or deflecting reforms. This paper analyses these transformations, from the emergence of the hydraulic mission and associated water bureaucracies to their adjustment and responses to changing conditions.

  3. Hybridized electromagnetic-triboelectric nanogenerator for scavenging air-flow energy to sustainably power temperature sensors.

    Science.gov (United States)

    Wang, Xue; Wang, Shuhua; Yang, Ya; Wang, Zhong Lin

    2015-04-28

    We report a hybridized nanogenerator with dimensions of 6.7 cm × 4.5 cm × 2 cm and a weight of 42.3 g that consists of two triboelectric nanogenerators (TENGs) and two electromagnetic generators (EMGs) for scavenging air-flow energy. Under an air-flow speed of about 18 m/s, the hybridized nanogenerator can deliver largest output powers of 3.5 mW for one TENG (in correspondence of power per unit mass/volume: 8.8 mW/g and 14.6 kW/m(3)) at a loading resistance of 3 MΩ and 1.8 mW for one EMG (in correspondence of power per unit mass/volume: 0.3 mW/g and 0.4 kW/m(3)) at a loading resistance of 2 kΩ, respectively. The hybridized nanogenerator can be utilized to charge a capacitor of 3300 μF to sustainably power four temperature sensors for realizing self-powered temperature sensor networks. Moreover, a wireless temperature sensor driven by a hybridized nanogenerator charged Li-ion battery can work well to send the temperature data to a receiver/computer at a distance of 1.5 m. This work takes a significant step toward air-flow energy harvesting and its potential applications in self-powered wireless sensor networks.

  4. Critical heat flux phenomena in flow boiling during step wise and ramp wise power transients

    International Nuclear Information System (INIS)

    Celata, G.P.; Cumo, M.; D'Annibale, F.; Farello, G.E.; Abou Said, S.

    1987-01-01

    The present paper deals with the results of an experimental investigation of the forced flow critical heat flux during power transients in a vertically heated channel. Experiments were carried out with a Refrigerant-12 1oop employing a circular test section which was electrically and uniformly heated. The power transients were performed with the step-wise and ramp-wise increase of the power to the test section. The test parameters included several values of the initial power (before the transient) and the final power (at the end of the transient) in the case of step-wise transients and the slope of the ramp in the case of ramp-wise transients. The pressure and specific mass flow rate, which were kept constant during the power transient,were varied from 1.2 to 2.7 MPa and 850 to 1500 Kg/sm 2 , respectively. Correlations of the experimental data for the time-to-crisis in terms of the independent parameters of the system are also proposed and verified for different values of pressure,mass flow rate, and inlet subcooling

  5. A New Real Time Lyapunov Based Controller for Power Quality Improvement in Unified Power Flow Controllers Using Direct Matrix Converters

    Directory of Open Access Journals (Sweden)

    Joaquim Monteiro

    2017-06-01

    Full Text Available This paper proposes a Direct Matrix Converter operating as a Unified Power Flow Controller (DMC-UPFC with an advanced control method for UPFC, based on the Lyapunov direct method, presenting good results in power quality assessment. This control method is used for real-time calculation of the appropriate matrix switching state, determining which switching state should be applied in the following sampling period. The control strategy takes into account active and reactive power flow references to choose the vector converter closest to the optimum. Theoretical principles for this new real-time vector modulation and control applied to the DMC-UPFC with input filter are established. The method needs DMC-UPFC dynamic equations to be solved just once in each control cycle, to find the required optimum vector, in contrast to similar control methods that need 27 vector estimations per control cycle. The designed controller’s performance was evaluated using Matlab/Simulink software. Controllers were also implemented using a digital signal processing (DSP system and matrix hardware. Simulation and experimental results show decoupled transmission line active (P and reactive (Q power control with zero theoretical error tracking and fast response. Output currents and voltages show small ripple and low harmonic content.

  6. Modeling and Vulnerability Analysis of Cyber-Physical Power Systems Considering Network Topology and Power Flow Properties

    Directory of Open Access Journals (Sweden)

    Jia Guo

    2017-01-01

    Full Text Available Conventional power systems are developing into cyber-physical power systems (CPPS with wide applications of communication, computer and control technologies. However, multiple practical cases show that the failure of cyber layers is a major factor leading to blackouts. Therefore, it is necessary to discuss the cascading failure process considering cyber layer failures and analyze the vulnerability of CPPS. In this paper, a CPPS model, which consists of cyber layer, physical layer and cyber-physical interface, is presented using complex network theory. Considering power flow properties, the impacts of cyber node failures on the cascading failure propagation process are studied. Moreover, two vulnerability indices are established from the perspective of both network structure and power flow properties. A vulnerability analysis method is proposed, and the CPPS performance before and after cascading failures is analyzed by the proposed method to calculate vulnerability indices. In the case study, three typical scenarios are analyzed to illustrate the method, and vulnerabilities under different interface strategies and attack strategies are compared. Two thresholds are proposed to value the CPPS vulnerability roughly. The results show that CPPS is more vulnerable under malicious attacks and cyber nodes with high indices are vulnerable points which should be reinforced.

  7. Optimal Power Flow in Multiphase Radial Networks with Delta Connections: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Low, Steven H. [California Institute of Technology

    2017-11-27

    This paper focuses on multiphase radial distribution networks with mixed wye and delta connections, and proposes a semidefinite relaxation of the AC optimal power flow (OPF) problem. Two multiphase power-flow models are developed to facilitate the integration of delta-connected generation units/loads in the OPF problem. The first model extends traditional branch flow models - and it is referred to as extended branch flow model (EBFM). The second model leverages a linear relationship between per-phase power injections and delta connections, which holds under a balanced voltage approximation (BVA). Based on these models, pertinent OPF problems are formulated and relaxed to semidefinite programs (SDPs). Numerical studies on IEEE test feeders show that SDP relaxations can be solved efficiently by a generic optimization solver. Numerical evidences indicate that solving the resultant SDP under BVA is faster than under EBFM. Moreover, both SDP solutions are numerically exact with respect to voltages and branch flows. It is also shown that the SDP solution under BVA has a small optimality gap, while the BVA model is accurate in the sense that it reflects actual system voltages.

  8. Equivalent model and power flow model for electric railway traction network

    Science.gov (United States)

    Wang, Feng

    2018-05-01

    An equivalent model of the Cable Traction Network (CTN) considering the distributed capacitance effect of the cable system is proposed. The model can be divided into 110kV side and 27.5kV side two kinds. The 110kV side equivalent model can be used to calculate the power supply capacity of the CTN. The 27.5kV side equivalent model can be used to solve the voltage of the catenary. Based on the equivalent simplified model of CTN, the power flow model of CTN which involves the reactive power compensation coefficient and the interaction of voltage and current, is derived.

  9. Strong enhancement of streaming current power by application of two phase flow

    NARCIS (Netherlands)

    Xie, Yanbo; Sherwood, John D.; Shui, Lingling; van den Berg, Albert; Eijkel, Jan C.T.

    2011-01-01

    We show that the performance of a streaming-potential based microfluidic energy conversion system can be strongly en-hanced by the use of two phase flow. In single-phase systems, the internal conduction current induced by the streaming poten-tial limits the output power, while in a two-phase system

  10. Strong enhancement of straeming current power by application of two phase flow

    NARCIS (Netherlands)

    Xie, Yanbo; Sherwood, John D.; Shui, Lingling; van den Berg, Albert; Eijkel, Jan C.T.

    2011-01-01

    We show that the performance of a streaming-potential based microfluidic energy conversion system can be strongly enhanced by the use of two phase flow. Injection of gas bubbles into a liquid-filled channel increases both the maximum output power and the energy conversion efficiency. In single-phase

  11. Power flow in the interior and exterior of cylindrical coated nanoparticles

    DEFF Research Database (Denmark)

    Arslanagic, Samel

    2012-01-01

    concentrically with a silver, gold, or copper nanoshell. Particular attention is devoted to both the direction and the magnitude of the power flow density inside and outside of such particles. The results for the active coated nanoparticles are related to those of the corresponding passive designs at optical...

  12. Optimal Power Flow for resistive DC Network : A Port-Hamiltonian approach

    NARCIS (Netherlands)

    Benedito, Ernest; del Puerto-Flores, D.; Doria-Cerezo, A.; Scherpen, Jacquelien M.A.; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    This paper studies the optimal power flow problem for resistive DC networks. The gradient method algorithm is written in a port-Hamiltonian form and the stability of the resulting dynamics is studied. Stability conditions are provided for general cyclic networks and a solution, when these conditions

  13. Price-based optimal control of power flow in electrical energy transmission networks

    NARCIS (Netherlands)

    Jokic, A.; Lazar, M.; Bosch, van den P.P.J.; Bemporad, A.; Bicchi, A.; Buttazzo, G.

    2007-01-01

    This article presents a novel control scheme for achieving optimal power balancing and congestion control in electrical energy transmission networks via nodal prices. We develop an explicit controller that guarantees economically optimal steady-state operation while respecting all line flow

  14. Optimal Power Flow in three-phase islanded microgrids with inverter interfaced units

    DEFF Research Database (Denmark)

    Sanseverino, Eleonora Riva; Quang, Ninh Nguyen; Di Silvestre, Maria Luisa

    2015-01-01

    In this paper, the solution of the Optimal Power Flow (OPF) problem for three phase islanded microgrids is studied, the OPF being one of the core functions of the tertiary regulation level for an AC islanded microgrid with a hierarchical control architecture. The study also aims at evaluating the...

  15. The creation of hypersonic flows by a powerful impulse capillary discharge

    Science.gov (United States)

    Pashchina, A. S.; Karmatsky, R. E.; Klimov, A. I.

    2017-11-01

    The possibility of using a powerful pulsed capillary discharge to produce quasi-stationary highspeed plasma flows with characteristic Mach numbers M = 3-10 and temperatures T = 3000-6000 K has been experimentally substantiated. In a rarefied gas atmosphere ( p ∞ condensed particles in a carbon-containing plasma.

  16. Second-order small-disturbance solutions for hypersonic flow over power-law bodies

    Science.gov (United States)

    Townsend, J. C.

    1975-01-01

    Similarity solutions were found which give the adiabatic flow of an ideal gas about two-dimensional and axisymmetric power-law bodies at infinite Mach number to second order in the body slenderness parameter. The flow variables were expressed as a sum of zero-order and perturbation similarity functions for which the axial variations in the flow equations separated out. The resulting similarity equations were integrated numerically. The solutions, which are universal functions, are presented in graphic and tabular form. To avoid a singularity in the calculations, the results are limited to body power-law exponents greater than about 0.85 for the two-dimensional case and 0.75 for the axisymmetric case. Because of the entropy layer induced by the nose bluntness (for power-law bodies other than cones and wedges), only the pressure function is valid at the body surface. The similarity results give excellent agreement with the exact solutions for inviscid flow over wedges and cones having half-angles up to about 20 deg. They give good agreement with experimental shock-wave shapes and surface-pressure distributions for 3/4-power axisymmetric bodies, considering that Mach number and boundary-layer displacement effects are not included in the theory.

  17. Distributed AC power flow method for AC and AC-DC hybrid ...

    African Journals Online (AJOL)

    ... on voltage level and R/X ratio in the formulation itself. DPFM is applied on a 10 bus, low voltage, microgrid system giving a better voltage profile.. Keywords: Microgrid (MG), Distributed Energy Resources (DER), Particle Swarm Optimization (OPF), Time varying inertia weight (TVIW), Distributed power flow method (DPFM) ...

  18. Analytical Solution of Unsteady Gravity Flows of A Power-Law Fluid ...

    African Journals Online (AJOL)

    We present an analytical study of unsteady non-linear rheological effects of a power-law fluid under gravity. The fluid flows through a porous medium. The governing equations are derived and similarity solutions are determined. The results show the existence of traveling waves. It is assumed that the viscosity is temperature ...

  19. Asymptotic expansion of unsteady gravity flow of a power-law fluid ...

    African Journals Online (AJOL)

    We present a paper on the asymptotic expansion of unsteady non-linear rheological effects of a power-law fluid under gravity. The fluid flows through a porous medium. The asymptotic expansion is employed to obtain solution of the nonlinear problem. The results show the existence of traveling waves. It is assumed that the ...

  20. An Algorithm for the Design of an Axial Flow Compressor of a Power ...

    African Journals Online (AJOL)

    This paper focuses on the development of an algorithm for designing an axial flow compressor for a power generation gas turbine and attempts to bring to the public domain some parameters regarded as propriety data by plant manufacturers. The theory used in this work is based on simple thermodynamics and ...

  1. Three-dimensional power Doppler sonography: imaging and quantifying blood flow and vascularization.

    Science.gov (United States)

    Pairleitner, H; Steiner, H; Hasenoehrl, G; Staudach, A

    1999-08-01

    To assess the feasibility of imaging low-velocity blood flow in adnexal masses by transvaginal three-dimensional power Doppler sonography, to analyze three-dimensional power Doppler sonography data sets with a new computer-assisted method and to test the reproducibility of the technique. A commercially available 5-MHz Combison 530 ultrasound system was used to perform three-dimensional power Doppler sonography transvaginally. A cube (= volume of interest) was defined enclosing the vessels of the cyst and the Cartesian characteristics were stored on a hard disk. This cube was analyzed using specially designed software. Five indices representing vascularization (the vascularization index (VI) or blood flow (the flow index (FI)) or both (the vascularization-flow index (VFI)) were calculated. The intraobserver repeatability of cube definition and scan repetition was assessed using Hartley's test for homogeneous variances. Interobserver agreement was assessed by the Pearson correlation coefficient. Imaging of vessels with low-velocity blood flow by three-dimensional power Doppler sonography and cube definition was possible in all adnexal massed studied. In some cases even induced non-vascular flow related to endometriosis was detected. The calculated F value with intraobserver repeated Cartesian file-saving ranged from 0 to 18.8, with intraobserver scan repetition from 4.74 to 24.8 for VI, FI 1, FI 2 and VFI 1; for VFI 2 the calculated F value was 64. The interobserver correlation coefficient ranged between 0.83 and 0.92 for VI, FI 1, FI 2 and VFI 1; for VFI 2 the correlation coefficient was less than 0.75. Vessels with low-velocity blood flow can be imaged using three-dimensional power Doppler sonography. Induced non-vascular flow was detected in endometriotic cyst fluid. Three-dimensional power Doppler sonography combined with the cube method gave reproducible information for all indices except VFI 2. These indices might prove to be a new predictor in all fields of

  2. CHF during flow rate, pressure and power transients in heated channels

    International Nuclear Information System (INIS)

    Celata, G.P.; Cumo, M.

    1987-01-01

    The behaviour of forced two-phase flows following inlet flow rate, pressure and power transients is presented here with reference to experiments performed with a R-12 loop. A circular duct, vertical test section (L = 2300 mm; D = 7.5 mm) instrumented with fluid (six) and wall (twelve) thermocouples has been employed. Transients have been carried out performing several values of flow decays (exponential decrease), depressurization rates (exponential decrease) and power inputs (step-wise increase). Experimental data have shown the complete inadequacy of steady-state critical heat flux correlations in predicting the onset of boiling crisis during fast transients. Data analysis for a better theoretical prediction of CHF occurrence during transient conditions has been accomplished, and design correlations for critical heat flux and time-to-crisis predictions have been proposed for the different types of transients

  3. Hydrogen consumption and power density in a co-flow planar SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Ben Moussa, Hocine; Zitouni, Bariza [Laboratoire d' etude des systemes energetiques industriels (LESEI), Universite de Batna, Batna (Algeria); Oulmi, Kafia [Laboratoire de chimie et de chimie de l' environnement, Universite de Batna, Batna (Algeria); Mahmah, Bouziane; Belhamel, Maiouf [CDER, BP. 62 Route de l' Observatoire. Bouzareah. Alger (Algeria); Mandin, Philippe [Centre de Developpement des Energies Renouvelables (CDER), LECA, UMR 7575 CNRS-ENSCP Paris 6 (France)

    2009-06-15

    In the present work, power density and hydrogen consumption in a co-flow planar solid oxide fuel cell (SOFC) are studied according to the inlet functional parameters; such as the operational temperature, the operational pressure, the flow rates and the mass fractions of the species. Furthermore, the effect of the cell size is investigated. The results of a zero and a one-dimensional numerical electro-dynamic model predict the remaining quantity of the fed hydrogen at the output of the anode flow channel. The remaining hydrogen quantities and the SOFC's power density obtained are discussed as a function of the inlet functional parameters, the geometrical configuration of the cell and several operating cell voltages values. (author)

  4. Pulsed operation of high-power light emitting diodes for imaging flow velocimetry

    International Nuclear Information System (INIS)

    Willert, C; Klinner, J; Moessner, S; Stasicki, B

    2010-01-01

    High-powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry in side-scatter imaging arrangements. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 W. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous current damage threshold, light pulses can be generated that are sufficient to illuminate and image micron-sized particles in flow velocimetry. Time-resolved PIV measurements in water at a framing rate of 2kHz are presented. The feasibility of LED-based PIV measurements in air is also demonstrated

  5. Load Flow and Short Circuit Analysis of the Class III Power System of HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. K.; Jung, H. S

    2005-12-15

    The planning, design, and operation of electric power system require engineering studies to assist in the evaluation of the system performance, reliability, safety and economics. The Class III power of HANARO supplies power for not only HANARO but also RIPF and IMEF. The starting current of most ac motors is five to ten times normal full load current. The loads of the Class III power are connected in consecutive orders at an interval for 10 seconds to avoid excessive voltage drop. This technical report deals with the load flow study and motor starting study for the Class III power of HANARO using ETAP(Electrical Transient Analyzer Program) to verify the capacity of the diesel generator. Short-circuit studies are done to determine the magnitude of the prospective currents flowing throughout the power system at various time intervals after a fault occurs. Short-circuit studies can be performed at the planning stage in order to help finalize the system layout, determine voltage levels, and size cables, transformers, and conductors. From this study, we verify the short circuit current capacity of air circuit breaker(ACB) and automatic transfer switch(ATS) of the Class III power.

  6. Evaluation of the effect of reactant gases mass flow rates on power density in a polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Kahveci, E. E.; Taymaz, I.

    2018-03-01

    In this study it was experimentally investigated the effect of mass flow rates of reactant gases which is one of the most important operational parameters of polymer electrolyte membrane (PEM) fuel cell on power density. The channel type is serpentine and single PEM fuel cell has an active area of 25 cm2. Design-Expert 8.0 (trial version) was used with four variables to investigate the effect of variables on the response using. Cell temperature, hydrogen mass flow rate, oxygen mass flow rate and humidification temperature were selected as independent variables. In addition, the power density was used as response to determine the combined effects of these variables. It was kept constant cell and humidification temperatures while changing mass flow rates of reactant gases. From the results an increase occurred in power density with increasing the hydrogen flow rates. But oxygen flow rate does not have a significant effect on power density within determined mass flow rates.

  7. Nonlinear Slewing Spacecraft Control Based on Exergy, Power Flow, and Static and Dynamic Stability

    Science.gov (United States)

    Robinett, Rush D.; Wilson, David G.

    2009-10-01

    This paper presents a new nonlinear control methodology for slewing spacecraft, which provides both necessary and sufficient conditions for stability by identifying the stability boundaries, rigid body modes, and limit cycles. Conservative Hamiltonian system concepts, which are equivalent to static stability of airplanes, are used to find and deal with the static stability boundaries: rigid body modes. The application of exergy and entropy thermodynamic concepts to the work-rate principle provides a natural partitioning through the second law of thermodynamics of power flows into exergy generator, dissipator, and storage for Hamiltonian systems that is employed to find the dynamic stability boundaries: limit cycles. This partitioning process enables the control system designer to directly evaluate and enhance the stability and performance of the system by balancing the power flowing into versus the power dissipated within the system subject to the Hamiltonian surface (power storage). Relationships are developed between exergy, power flow, static and dynamic stability, and Lyapunov analysis. The methodology is demonstrated with two illustrative examples: (1) a nonlinear oscillator with sinusoidal damping and (2) a multi-input-multi-output three-axis slewing spacecraft that employs proportional-integral-derivative tracking control with numerical simulation results.

  8. Dual plane problems for creeping flow of power-law incompressible medium

    Directory of Open Access Journals (Sweden)

    Dmitriy S. Petukhov

    2016-09-01

    Full Text Available In this paper, we consider the class of solutions for a creeping plane flow of incompressible medium with power-law rheology, which are written in the form of the product of arbitrary power of the radial coordinate by arbitrary function of the angular coordinate of the polar coordinate system covering the plane. This class of solutions represents the asymptotics of fields in the vicinity of singular points in the domain occupied by the examined medium. We have ascertained the duality of two problems for a plane with wedge-shaped notch, at which boundaries in one of the problems the vector components of the surface force vanish, while in the other—the vanishing components are the vector components of velocity, We have investigated the asymptotics and eigensolutions of the dual nonlinear eigenvalue problems in relation to the rheological exponent and opening angle of the notch for the branch associated with the eigenvalue of the Hutchinson–Rice–Rosengren problem learned from the problem of stress distribution over a notched plane for a power law medium. In the context of the dual problem we have determined the velocity distribution in the flow of power-law medium at the vertex of a rigid wedge, We have also found another two eigenvalues, one of which was determined by V. V. Sokolovsky for the problem of power-law fluid flow in a convergent channel.

  9. Power flow control based solely on slow feedback loop for heart pump applications.

    Science.gov (United States)

    Wang, Bob; Hu, Aiguo Patrick; Budgett, David

    2012-06-01

    This paper proposes a new control method for regulating power flow via transcutaneous energy transfer (TET) for implantable heart pumps. Previous work on power flow controller requires a fast feedback loop that needs additional switching devices and resonant capacitors to be added to the primary converter. The proposed power flow controller eliminates these additional components, and it relies solely on a slow feedback loop to directly drive the primary converter to meet the heart pump power demand and ensure zero voltage switching. A controlled change in switching frequency varies the resonant tank shorting period of a current-fed push-pull resonant converter, thus changing the magnitude of the primary resonant voltage, as well as the tuning between primary and secondary resonant tanks. The proposed controller has been implemented successfully using an analogue circuit and has reached an end-to-end power efficiency of 79.6% at 10 W with a switching frequency regulation range of 149.3 kHz to 182.2 kHz.

  10. Comparison of power Doppler and color Doppler ultrasonography in the detection of intrasticular blood flow of normal infants

    International Nuclear Information System (INIS)

    Shin, Sung Ran; Lee, Ho Kyoung; Lee, Won Gyun; Youk, Dong Joon; Rho, Taek Soo; Lee, Min Jin; Lee, Sang Chun

    1999-01-01

    To compare color Doppler ultrasonography (US) and power Doppler US in the detection of intratesticular blood flow in normal infants and to asses the symmetry of blood flow. Testicular blood flow was assessed prospectively in 100 testes of 50 infants with both power and color Doppler US. We compared the power Doppler with color Doppler to detect intratesticular blood. When the flow was detected, intratesticular blood flow was graded as follows: grade 1: single intratesticular Doppler signal ; grade 2: multiple intratesticular Doppler signals. The symmetry of intratesticular flow was assessed by using the same method. Intratesticular flow was detected in 72 (72%) and 68 (68%) testes on power and color Doppler US, respectively. In 76 testes (76%), intratesticular flow was detected in either one or both techniques. On power Doppler US, grade 1 was seen in 40 tests and grade 2 in 32 testes. On color Doppler US, grade 1 was noted in 52 testes and grade 2 in 16 testes. Testicular blood flow was symmetric on both power and color Doppler US in each patient. There was no difference between power Doppler and color Doppler ultrasonography in detecting intratesticular blood flow in normal infants.

  11. Method to predetermine current/power flow change in a dc grid

    DEFF Research Database (Denmark)

    2017-01-01

    occurs at one of the AC/DC converters; establishing a generalized droop feedback gain matrix G; controlling current/power flow within DC grid towards predefined setpoints, by use of control law. The invention presents an analytical approach to derive the generalized feedback gain allowing......The invention relates to a method for controlling current/power flow within a power transmission system, comprising two or more interconnected converter stations. The method comprises the steps of: providing a DC admittance matrix given from the DC grid; providing a current distribution matrix...... for a number of, such as for all possible AC/DC converter outages; providing a DC bus voltage vector for the DC grid; the DC bus voltage vector being a vector containing the values of the voltage change at the AC/DC converters, measured at the AC/DC converters, before, during and after a forced current change...

  12. Improved coal grinding and fuel flow control in thermal power plants

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Bendtsen, Jan Dimon

    2011-01-01

    A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated in the m......A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated...... as well as when parameter uncertainties and noise are present. The proposed controller lowers the grinding power consumption while in most cases exhibiting superior performance in comparison with the PID controller....

  13. Dense granular Flows: a conceptual design of high-power neutron source

    Directory of Open Access Journals (Sweden)

    Yang Lei

    2017-01-01

    Full Text Available A high-power neutron source system is very useful for multifunctional applications, such as material facilities for advanced nuclear power, space radiation studies, radiography and tomography. Here the idea of inclined dense granular flow is utilized and developed in a new conceptual design of a compact high-power target to produce a high-energy and high-flux neutron irradiation (the flux is up to 1015 n/cm2/s or even 1016. Comparing to the traditional solid and liquid heavy metal targets, this design has advantages in material choice, fluid stability, heat removal, etc. In this paper the natures of the granular flows in an inclined chute are investigated and preliminary experimental and numerical results are reported. Then the feasibility of this design is discussed.

  14. Modeling of unified power quality conditioner (UPQC) in distribution systems load flow

    International Nuclear Information System (INIS)

    Hosseini, M.; Shayanfar, H.A.; Fotuhi-Firuzabad, M.

    2009-01-01

    This paper presents modeling of unified power quality conditioner (UPQC) in load flow calculations for steady-state voltage compensation. An accurate model for this device is derived to use in load flow calculations. The rating of this device as well as direction of reactive power injection required to compensate voltage to the desired value (1 p.u.) is derived and discussed analytically and mathematically using phasor diagram method. Since performance of the compensator varies when it reaches to its maximum capacity, modeling of UPQC in its maximum rating of reactive power injection is derived. The validity of the proposed model is examined using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of UPQC for under voltage problem mitigation in the distribution network is determined. The results show the validity of the proposed model for UPQC in large distribution systems.

  15. Modeling of unified power quality conditioner (UPQC) in distribution systems load flow

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, M.; Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran); Fotuhi-Firuzabad, M. [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran)

    2009-06-15

    This paper presents modeling of unified power quality conditioner (UPQC) in load flow calculations for steady-state voltage compensation. An accurate model for this device is derived to use in load flow calculations. The rating of this device as well as direction of reactive power injection required to compensate voltage to the desired value (1 p.u.) is derived and discussed analytically and mathematically using phasor diagram method. Since performance of the compensator varies when it reaches to its maximum capacity, modeling of UPQC in its maximum rating of reactive power injection is derived. The validity of the proposed model is examined using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of UPQC for under voltage problem mitigation in the distribution network is determined. The results show the validity of the proposed model for UPQC in large distribution systems. (author)

  16. Multi-objective optimal power flow for active distribution network considering the stochastic characteristic of photovoltaic

    Science.gov (United States)

    Zhou, Bao-Rong; Liu, Si-Liang; Zhang, Yong-Jun; Yi, Ying-Qi; Lin, Xiao-Ming

    2017-05-01

    To mitigate the impact on the distribution networks caused by the stochastic characteristic and high penetration of photovoltaic, a multi-objective optimal power flow model is proposed in this paper. The regulation capability of capacitor, inverter of photovoltaic and energy storage system embedded in active distribution network are considered to minimize the expected value of active power the T loss and probability of voltage violation in this model. Firstly, a probabilistic power flow based on cumulant method is introduced to calculate the value of the objectives. Secondly, NSGA-II algorithm is adopted for optimization to obtain the Pareto optimal solutions. Finally, the best compromise solution can be achieved through fuzzy membership degree method. By the multi-objective optimization calculation of IEEE34-node distribution network, the results show that the model can effectively improve the voltage security and economy of the distribution network on different levels of photovoltaic penetration.

  17. A Sufficient Condition on Convex Relaxation of AC Optimal Power Flow in Distribution Networks

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Wang, Jianhui

    2016-01-01

    This paper proposes a sufficient condition for the convex relaxation of AC Optimal Power Flow (OPF) in radial distribution networks as a second order cone program (SOCP) to be exact. The condition requires that the allowed reverse power flow is only reactive or active, or none. Under the proposed...... solution of the SOCP can be converted to an optimal solution of the original AC OPF. The efficacy of the convex relaxation to solve the AC OPF is demonstrated by case studies of an optimal multi-period planning problem of electric vehicles (EVs) in distribution networks....... sufficient condition, the feasible sub-injection region (power injections of nodes excluding the root node) of the AC OPF is convex. The exactness of the convex relaxation under the proposed condition is proved through constructing a group of monotonic series with limits, which ensures that the optimal...

  18. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Eric [Univ. of Connecticut, Storrs, CT (United States); Gell, Maurice [Univ. of Connecticut, Storrs, CT (United States)

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm⁻¹K⁻¹ in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al₂O₃ and TiO₂, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium

  19. Optimal Water-Power Flow Problem: Formulation and Distributed Optimal Solution

    Energy Technology Data Exchange (ETDEWEB)

    Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zamzam, Admed S. [University of Minnesota; Sidiropoulos, Nicholas D. [University of Minnesota; Taylor, Josh A. [University of Toronto

    2018-01-12

    This paper formalizes an optimal water-power flow (OWPF) problem to optimize the use of controllable assets across power and water systems while accounting for the couplings between the two infrastructures. Tanks and pumps are optimally managed to satisfy water demand while improving power grid operations; {for the power network, an AC optimal power flow formulation is augmented to accommodate the controllability of water pumps.} Unfortunately, the physics governing the operation of the two infrastructures and coupling constraints lead to a nonconvex (and, in fact, NP-hard) problem; however, after reformulating OWPF as a nonconvex, quadratically-constrained quadratic problem, a feasible point pursuit-successive convex approximation approach is used to identify feasible and optimal solutions. In addition, a distributed solver based on the alternating direction method of multipliers enables water and power operators to pursue individual objectives while respecting the couplings between the two networks. The merits of the proposed approach are demonstrated for the case of a distribution feeder coupled with a municipal water distribution network.

  20. Power Disturbances Close to Hydrodynamic Instability in Natural Circulation Two-Phase Flow

    International Nuclear Information System (INIS)

    Mathisen, R.P.; Eklind, O.

    1967-07-01

    In certain boiling reactor designs high positive void coefficients could exist and under certain circumstances cause instability. Control systems may therefore be desired. In such a controlled reactor there could remain superimposed low frequency power oscillations of some magnitude. The object of the current experiments in SKALVAN was to examine whether or not such slow oscillations could influence the hydrodynamic stability limit of the individual boiling channels. While operating the loop close to the threshold of hydrodynamic instability, the power was pulsed in the boiling channel. The pulse widths had a lower limit of 0.65 sec due to the contactor time constant. The square wave power oscillation amplitude ΔQ/Q was 12.2 %, and the interval T between the pulses was varied in the range 0 0 /T 0 was the mass flow oscillation period. The corresponding mass flow oscillations remained damped for all disturbance periods which were examined. With minimum test section inlet restrictions the power level at instability was much lower than that at burnout conditions. At higher restrictions these phenomena occurred at approximately equivalent power levels. The experiments with minimum inlet restrictions were also performed beyond the instability threshold. In this case it was possible to exceed the nominal burnout point temporarily by 5 per cent or more for periods of the order of magnitude 1 second. Even now the boiling channel conditions were not so severely affected that the burnout detectors tripped, and the power disturbances caused low frequency modulated wave trains

  1. A Power Load Distribution Algorithm to Optimize Data Center Electrical Flow

    Directory of Open Access Journals (Sweden)

    Paulo Maciel

    2013-07-01

    Full Text Available Energy consumption is a matter of common concern in the world today. Research demonstrates that as a consequence of the constantly evolving and expanding field of information technology, data centers are now major consumers of electrical energy. Such high electrical energy consumption emphasizes the issues of sustainability and cost. Against this background, the present paper proposes a power load distribution algorithm (PLDA to optimize energy distribution of data center power infrastructures. The PLDA, which is based on the Ford-Fulkerson algorithm, is supported by an environment called ASTRO, capable of performing the integrated evaluation of dependability, cost and sustainability. More specifically, the PLDA optimizes the flow distribution of the energy flow model (EFM. EFMs are responsible for estimating sustainability and cost issues of data center infrastructures without crossing the restrictions of the power capacity that each device can provide (power system or extract (cooling system. Additionally, a case study is presented that analyzed seven data center power architectures. Significant results were observed, achieving a reduction in power consumption of up to 15.5%.

  2. Study of Power Flow Algorithm of AC/DC Distribution System including VSC-MTDC

    Directory of Open Access Journals (Sweden)

    Haifeng Liang

    2015-08-01

    Full Text Available In recent years, distributed generation and a large number of sensitive AC and DC loads have been connected to distribution networks, which introduce a series of challenges to distribution network operators (DNOs. In addition, the advantages of DC distribution networks, such as the energy conservation and emission reduction, mean that the voltage source converter based multi-terminal direct current (VSC-MTDC for AC/DC distribution systems demonstrates a great potential, hence drawing growing research interest. In this paper, considering losses of the reactor, the filter and the converter, a mathematical model of VSC-HVDC for the load flow analysis is derived. An AC/DC distribution network architecture has been built, based on which the differences in modified equations of the VSC-MTDC-based network under different control modes are analyzed. In addition, corresponding interface functions under five control modes are provided, and a back/forward iterative algorithm which is applied to power flow calculation of the AC/DC distribution system including VSC-MTDC is proposed. Finally, by calculating the power flow of the modified IEEE14 AC/DC distribution network, the efficiency and validity of the model and algorithm are evaluated. With various distributed generations connected to the network at appropriate locations, power flow results show that network losses and utilization of transmission networks are effectively reduced.

  3. Effect of coolant flow rate on the power at onset of nucleate boiling in a swimming pool type research reactor

    International Nuclear Information System (INIS)

    Khan, L.A.; Ahmad, N.; Ahmad, S.

    1998-01-01

    The effect of flow rate of coolant on power of Onset Nucleate Boiling (ONB) in a reference core of a swimming pool type research reactor has been studied using a as standard computer code PARET. It has been found that the decrease in the coolant flow rate results in a corresponding decrease in power at ONB. (author)

  4. Four-level time decomposition quasi-static power flow and successive disturbances analysis. [Power system disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, S M [Nikola Tesla Inst., Belgrade (YU)

    1990-01-01

    This paper presents a model and an appropriate numerical procedure for a four-level time decomposition quasi-static power flow and successive disturbances analysis of power systems. The analysis consists of the sequential computation of the zero, primary, secondary and tertiary quasi-static states and of the estimation of successive structural disturbances during the 1200 s dynamics after a structural disturbance. The model is developed by detailed inspection of the time decomposition characteristics of automatic protection and control devices. Adequate speed of the numerical procedure is attained by a specific application of the inversion matrix lemma and the decoupled model constant coefficient matrices. The four-level time decomposition quasi-static method is intended for security and emergency analysis. (author).

  5. Analysis and characterization of security regions in power systems. Part I. Load flow feasibility conditions in power networks

    Energy Technology Data Exchange (ETDEWEB)

    Jarjis, J; Galiana, F D

    1980-03-01

    A set theoretic analysis of loadflow feasibility of a general power network with arbitrary PQ, PV and slack buses is presented. Load-flow feasibility is that property of a power network defining the theoretical limitations on the bus injections under which a steady state equilibrium exists. The set theoretic analysis is based on the study of the conical loadflow feasibility region. This region is characterised by a set of supporting hyperplanes each of which defines an explicit necessary condition for loadflow feasibility on the bus injections. A quantitative measure of loadflow feasibility for an arbitrary given operating injection vector is defined through a computable scalar stability margin. This stability margin permits the loadflow feasibility of different injections and network structures to be quantitatively compared and analysed.

  6. FIX-II/2032, BWR Pump Trip Experiment 2032, Simulation Mass Flow and Power Transients

    International Nuclear Information System (INIS)

    1988-01-01

    1 - Description of test facility: In the FIX-II pump trip experiments, mass flow and power transients were simulated subsequent to a total loss of power to the recirculation pumps in an internal pump boiling water reactor. The aim was to determine the initial power limit to give dryout in the fuel bundle for the specified transient. In addition, the peak cladding temperature was measured and the rewetting was studied. 2 - Description of test: Pump trip experiment 2032 was a part of test group 2, i.e. the mass flow transient was to simulate the pump coast down with a pump inertia of 11.3 kg.m -2 . The initial power in the 36-rod bundle was 4.44 MW which gave dryout after 1.4 s from the start of the flow transient. A maximum rod cladding temperature of 457 degrees C was measured. Rewetting was obtained after 7.6 s. 3 - Experimental limitations or shortcomings: No ECCS injection systems

  7. Regularized lattice Boltzmann model for immiscible two-phase flows with power-law rheology

    Science.gov (United States)

    Ba, Yan; Wang, Ningning; Liu, Haihu; Li, Qiang; He, Guoqiang

    2018-03-01

    In this work, a regularized lattice Boltzmann color-gradient model is developed for the simulation of immiscible two-phase flows with power-law rheology. This model is as simple as the Bhatnagar-Gross-Krook (BGK) color-gradient model except that an additional regularization step is introduced prior to the collision step. In the regularization step, the pseudo-inverse method is adopted as an alternative solution for the nonequilibrium part of the total distribution function, and it can be easily extended to other discrete velocity models no matter whether a forcing term is considered or not. The obtained expressions for the nonequilibrium part are merely related to macroscopic variables and velocity gradients that can be evaluated locally. Several numerical examples, including the single-phase and two-phase layered power-law fluid flows between two parallel plates, and the droplet deformation and breakup in a simple shear flow, are conducted to test the capability and accuracy of the proposed color-gradient model. Results show that the present model is more stable and accurate than the BGK color-gradient model for power-law fluids with a wide range of power-law indices. Compared to its multiple-relaxation-time counterpart, the present model can increase the computing efficiency by around 15%, while keeping the same accuracy and stability. Also, the present model is found to be capable of reasonably predicting the critical capillary number of droplet breakup.

  8. Simulation of Valve Operation for Flow Interrupt Test in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Kim, Jae Hyung; Shin, Dae Yong; Shin, Dong Woo; Kim, Charn Jung; Lee, Jung Hee

    2012-01-01

    The valve used in nuclear power plant must be qualified for the function according to the KEPIC MF. The test valve must be selected by shape and size, which is given by KEPIC MF. In the functional test, the mathematical model for the valve operation is needed. The mathematical model must be verified by the test, whose method and procedure is defined in KEPIC MF. The lack of analytical technique has lead to the poor mathematical model, with which the functional test for the big valve is impossible with analytical method. Especially, the tank and rupture disk in the flow test is not considered and the result of the analysis is so different to the real one. In these days, the 3D model for the flow interrupt test makes more accurate analysis. And no facility about functional test reduces the research will for the nuclear power plant valve. For this problem, the test facility for the functional test of the valve and pump in nuclear power plant has been made until 2012. With the test facility, the research project related the valve were initiated in KIMM( Korea Institute of Machinery and Materials). And the joint project to SNU(Seoul National University) has been going on the numerical analysis for the valve in nuclear power plant. Using the commercial software and user subroutine, UDF, the co-simulation with multi-body dynamic and fluid flow analysis and the addition of tank and rupture disk to the user subroutine make possible to simulate the flow interrupt test numerically. This is not simple and regular analysis, which was introduced in user subroutine. In order to simulate the real situation, the engineering work, related mathematical model, and the programming in the user subroutine are needed. This study is on the making the mathematical model for the functional test of the valve in nuclear power plan. The functional test is the real test procedure and defined in KEPIC MF

  9. Control of Vibratory Energy Harvesters in the Presence of Nonlinearities and Power-Flow Constraints

    Science.gov (United States)

    Cassidy, Ian L.

    control the harvester is infeasible due to the high levels of parasitic power required to operate the drive. For the case where a single-directional drive is used, a constraint on the directionality of power-flow is imposed on the system, which necessitates the use of nonlinear feedback. As such, a sub-optimal controller for power-flow-constrained vibratory energy harvesters is presented, which is analytically guaranteed to outperform the optimal static admittance controller. Finally, the last section of this dissertation explores a numerical approach to compute optimal discretized control manifolds for systems with power-flow constraints. Unlike the sub-optimal nonlinear controller, the numerical controller satisfies the necessary conditions for optimality by solving the stochastic Hamilton-Jacobi equation.

  10. Numerical Simulation of Groundwater Flow at Kori Nuclear Power Plant Site

    International Nuclear Information System (INIS)

    Sohn, Wook; Sohn, Soon Whan; Chon, Chul Min; Kim, Kue Youn

    2010-01-01

    Recently, the understanding of hydrogeological characteristics of nuclear power sites is getting more importance with increasing public concerns over the environment since such understanding is essential for an environmentally friendly operation of plants. For such understanding, the prediction of groundwater flow pattern onsite plays the most critical role since it is the most dynamic of the factors to be considered. In this study, the groundwater flow at the Kori Plant 1 site has been simulated numerically with aim of providing fundamental information needed for improving the understanding of the hydrogeological characteristics of the site

  11. Analysis and Experimental Verification of New Power Flow Control for Grid-Connected Inverter with LCL Filter in Microgrid

    Science.gov (United States)

    Gu, Herong; Guan, Yajuan; Wang, Huaibao; Wei, Baoze; Guo, Xiaoqiang

    2014-01-01

    Microgrid is an effective way to integrate the distributed energy resources into the utility networks. One of the most important issues is the power flow control of grid-connected voltage-source inverter in microgrid. In this paper, the small-signal model of the power flow control for the grid-connected inverter is established, from which it can be observed that the conventional power flow control may suffer from the poor damping and slow transient response. While the new power flow control can mitigate these problems without affecting the steady-state power flow regulation. Results of continuous-domain simulations in MATLAB and digital control experiments based on a 32-bit fixed-point TMS320F2812 DSP are in good agreement, which verify the small signal model analysis and effectiveness of the proposed method. PMID:24672304

  12. Analysis and experimental verification of new power flow control for grid-connected inverter with LCL filter in microgrid.

    Science.gov (United States)

    Gu, Herong; Guan, Yajuan; Wang, Huaibao; Wei, Baoze; Guo, Xiaoqiang

    2014-01-01

    Microgrid is an effective way to integrate the distributed energy resources into the utility networks. One of the most important issues is the power flow control of grid-connected voltage-source inverter in microgrid. In this paper, the small-signal model of the power flow control for the grid-connected inverter is established, from which it can be observed that the conventional power flow control may suffer from the poor damping and slow transient response. While the new power flow control can mitigate these problems without affecting the steady-state power flow regulation. Results of continuous-domain simulations in MATLAB and digital control experiments based on a 32-bit fixed-point TMS320F2812 DSP are in good agreement, which verify the small signal model analysis and effectiveness of the proposed method.

  13. Utilizing a vanadium redox flow battery to avoid wind power deviation penalties in an electricity market

    International Nuclear Information System (INIS)

    Turker, Burak; Arroyo Klein, Sebastian; Komsiyska, Lidiya; Trujillo, Juan José; Bremen, Lueder von; Kühn, Martin; Busse, Matthias

    2013-01-01

    Highlights: • Vanadium redox flow battery utilized for wind power grid integration was studied. • Technical and financial analyses at single wind farm level were performed. • 2 MW/6 MW h VRFB is suitable for mitigating power deviations for a 10 MW wind farm. • Economic incentives might be required in the short-term until the VRFB prices drop. - Abstract: Utilizing a vanadium redox flow battery (VRFB) for better market integration of wind power at a single wind farm level was evaluated. A model which combines a VRFB unit and a medium sized (10 MW) wind farm was developed and the battery was utilized to compensate for the deviations resulting from the forecast errors in an electricity market bidding structure. VRFB software model which was introduced in our previous paper was integrated with real wind power data, power forecasts and market data based on the Spanish electricity market. Economy of the system was evaluated by financial assessments which were done by considering the VRFB costs and the amount of deviation penalty payments resulting from forecast inaccuracies

  14. Blowdown mass flow measurements during the Power Burst Facility LOC-11C test

    International Nuclear Information System (INIS)

    Broughton, J.M.; MacDonald, P.E.

    1979-01-01

    An interpretation and evaluation of the two-phase coolant mass flow measurements obtained during Test LOC-11C performed in the Power Burst Facility (PBF) at the Idaho National Engineering Laboratory (INEL) are presented. Although a density gradient existed within the pipe between 1 and 6 s, the homogeneous flow model used to calculate the coolant mass flow from the measured mixture density, momentum flux, and volumetric flow was found to be generally satisfactory. A cross-sectional average density was determined by fitting a linear density gradient through the upper and lower chordal densities obtained from a three-beam gamma densitometer and then combining the result with the middle beam density. The integrated measured coolant mass flow was subsequently found to be within 5% if the initial mass inventory of the PBF loss-of-coolant accident (LOCA) system. The posttest calculations using the RELAP4/MOD6 computer code to determine coolant mass flow for Test LOC-11C also agreed well with the measured data

  15. Numerical Modeling of the Flow of a Power Law Ceramic Slurry in the Tape Casting Process

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Hattel, Jesper Henri

    2012-01-01

    Multilayer ceramics and their application have increased recently. One of the most common ways used to produce these products is tape casting. In this process the wet tape thickness is one of the most determining parameters affecting the final properties of the product and it is therefore of great...... interest to be able to control it. In the present work the flow of La0.85Sr0.15MnO3 (LSM) material in the doctor blade region is modelled numerically with ANSYS Fluent in combination with an Ostwald power law constitutive equation. Based on rheometer experiments the constants in the Ostwald power law...

  16. Inertia effects in the laminar radial flow of a power law fluid with an electromagnetic field

    International Nuclear Information System (INIS)

    Chen, C.-K.; Chen, K.-H.; Wu, C.-Y.

    1984-01-01

    An approximate study of the pressure distribution for the radial flow of a non-newtonian (power law) fluid between two parallel disks in the presence of an axial electrical field is obtained by using the momentum and energy integral methods. For a non-newtonian fluid it is shown that the inertia effect must be considered to be significant for the pressure distribution, especially for the power law fluids with n >= 1. Furthermore, it is seen that the inertia effect will also lower the load capacity of the disks. (Auth.)

  17. A trust region interior point algorithm for optimal power flow problems

    Energy Technology Data Exchange (ETDEWEB)

    Wang Min [Hefei University of Technology (China). Dept. of Electrical Engineering and Automation; Liu Shengsong [Jiangsu Electric Power Dispatching and Telecommunication Company (China). Dept. of Automation

    2005-05-01

    This paper presents a new algorithm that uses the trust region interior point method to solve nonlinear optimal power flow (OPF) problems. The OPF problem is solved by a primal/dual interior point method with multiple centrality corrections as a sequence of linearized trust region sub-problems. It is the trust region that controls the linear step size and ensures the validity of the linear model. The convergence of the algorithm is improved through the modification of the trust region sub-problem. Numerical results of standard IEEE systems and two realistic networks ranging in size from 14 to 662 buses are presented. The computational results show that the proposed algorithm is very effective to optimal power flow applications, and favors the successive linear programming (SLP) method. Comparison with the predictor/corrector primal/dual interior point (PCPDIP) method is also made to demonstrate the superiority of the multiple centrality corrections technique. (author)

  18. Characteristics of high gradient insulators for accelerator and high power flow applications

    International Nuclear Information System (INIS)

    Elizondo, J.M.; Krogh, M.L.; Smith, D.

    1997-07-01

    The high gradient insulator has been demonstrated to operate at levels comparable or better than special geometry or coated insulators. Some patented insulator configurations allow for sophisticated accelerator structures, high power flow interfaces, and microwave applications not previously possible. Sophisticated manufacturing techniques available at AlliedSignal FM and T made this development possible. Bipolar and high power flow applications are specially suited for present insulator designs. The insulator shows a beneficial effect when used under RF fields or RF structures. These insulators can be designed, to a first approximation, from simple electron flight path equations. With a recently developed model of surface flashover physics the authors completed a set of design calculations that include effects such as layer density and dielectric/metal thickness. Experimental data, obtained in the last few years of development, is presented and reviewed. Several insulator fabrication characteristics, indicating critical design parameters, are also presented

  19. Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

    Science.gov (United States)

    Walicka, A.

    2018-02-01

    In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

  20. Numerical simulation of flow field in shellside of heat exchanger in nuclear power plant

    International Nuclear Information System (INIS)

    Wang Xinliang; Qiu Jinrong; Gong Zili

    2010-01-01

    Heat exchanger is the important equipment of nuclear power plant. Numerical simulation can give the detail information inside the heat exchange, and has been an effective research method. The geometric structure of shell-and-tube heat exchanger is very complex and it is difficult to simulate the whole flow field presently. According to the structure characteristics of the heat exchanger, a periodic whole-section calculation model was presented. The numerical simulation of flow field in shellside of heat exchange of a nuclear power plant was done by using this model. The results of simulation show that heat transfer in the periodic section of the heat exchange is uniform, the heat transfer is enhanced by using baffles in heat exchange, and frictional resistance is primary from the effect of segmental baffles. (authors)

  1. Direct power production from a water salinity difference in a membrane-modified supercapacitor flow cell.

    Science.gov (United States)

    Sales, B B; Saakes, M; Post, J W; Buisman, C J N; Biesheuvel, P M; Hamelers, H V M

    2010-07-15

    The entropy increase of mixing two solutions of different salt concentrations can be harnessed to generate electrical energy. Worldwide, the potential of this resource, the controlled mixing of river and seawater, is enormous, but existing conversion technologies are still complex and expensive. Here we present a small-scale device that directly generates electrical power from the sequential flow of fresh and saline water, without the need for auxiliary processes or converters. The device consists of a sandwich of porous "supercapacitor" electrodes, ion-exchange membranes, and a spacer and can be further miniaturized or scaled-out. Our results demonstrate that alternating the flow of saline and fresh water through a capacitive cell allows direct autogeneration of voltage and current and consequently leads to power generation. Theoretical calculations aid in providing directions for further optimization of the properties of membranes and electrodes.

  2. Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

    Directory of Open Access Journals (Sweden)

    Walicka A.

    2018-02-01

    Full Text Available In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

  3. Cause Analysis of Flow Accelerated Corrosion and Erosion-Corrosion Cases in Korea Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. S.; Lee, S. H. [Korea Hydro and Nuclear Power Co., Ltd., Gyeongju (Korea, Republic of); Hwang, K. M. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of)

    2016-08-15

    Significant piping wall thinning caused by Flow-Accelerated Corrosion (FAC) and Erosion-Corrosion (EC) continues to occur, even after the Mihama Power Station unit 3 secondary pipe rupture in 2004, in which workers were seriously injured or died. Nuclear power plants in many countries have experienced FAC and EC-related cases in steam cycle piping systems. Korea has also experienced piping wall thinning cases including thinning in the downstream straight pipe of a check valve in a feedwater pump line, the downstream elbow of a control valve in a feedwater flow control line, and failure of the straight pipe downstream of an orifice in an auxiliary steam return line. Cause analyses were performed by reviewing thickness data using Ultrasonic Techniques (UT) and, Scanning Electron Microscope (SEM) images for the failed pipe, and numerical simulation results for FAC and EC cases in Korea Nuclear Power Plants. It was concluded that the main cause of wall thinning for the downstream pipe of a check valve is FAC caused by water vortex flow due to the internal flow shape of a check valve, the main cause of wall thinning for the downstream elbow of a control valve is FAC caused by a thickness difference with the upstream pipe, and the main cause of wall thinning for the downstream pipe of an orifice is FAC and EC caused by liquid droplets and vortex flow. In order to investigate more cases, additional analyses were performed with the review of a lot of thickness data for inspected pipes. The results showed that pipe wall thinning was also affected by the operating condition of upstream equipment. Management of FAC and EC based on these cases will focus on the downstream piping of abnormal or unusual operated equipment.

  4. Space station electrical power distribution analysis using a load flow approach

    Science.gov (United States)

    Emanuel, Ervin M.

    1987-01-01

    The space station's electrical power system will evolve and grow in a manner much similar to the present terrestrial electrical power system utilities. The initial baseline reference configuration will contain more than 50 nodes or busses, inverters, transformers, overcurrent protection devices, distribution lines, solar arrays, and/or solar dynamic power generating sources. The system is designed to manage and distribute 75 KW of power single phase or three phase at 20 KHz, and grow to a level of 300 KW steady state, and must be capable of operating at a peak of 450 KW for 5 to 10 min. In order to plan far into the future and keep pace with load growth, a load flow power system analysis approach must be developed and utilized. This method is a well known energy assessment and management tool that is widely used throughout the Electrical Power Utility Industry. The results of a comprehensive evaluation and assessment of an Electrical Distribution System Analysis Program (EDSA) is discussed. Its potential use as an analysis and design tool for the 20 KHz space station electrical power system is addressed.

  5. Heat transfer and fluid flow research relevant to India's nuclear power program

    International Nuclear Information System (INIS)

    Mehta, S.K.; Venkatraj, V.

    1988-01-01

    The Indian Nuclear Power Programme envisages three important stages viz., installation of thermal reactors, fast reactors and utilization of Thorium. By the year 2000 AD, it is proposed to have an installed total capacity of nuclear power of about 10,000 MWe. Starting from the present installed capacity of 1330 MWe, the additional contribution will be mainly made by thermal power reactors of the Pressurized Heavy Water type (PHWR). Apart from the reactors presently under construction about 12 numbers of 235 MWe units are planned to be constructed, which will be based on the standardized design of the reactors at Narora Atomic Power Project (NAPP). In addition, 10 units of 500 MWe capacity each, the design for which is currently under progress, will also be installed. The design, construction and operating agency is the Nuclear Power Board (NPB), while the Bhabha Atomic Research Centre (BARC) is responsible for the research and development work required. In addition to the programme on thermal power reactors, a thermal research reactor (DHRUVA) of 100 MWth capacity has been designed, constructed and has been commissioned. Some of the important heat transfer and fluid flow research problems relevant to the Indian nuclear power and research reactors are discussed in this paper

  6. SLIPPER PERFORMANCE INVESTIGATION IN AXIAL PISTON PUMPS AND MOTORS-FLOW AND VISCOUS POWER LOSSES

    Directory of Open Access Journals (Sweden)

    A. Osman KURBAN

    1997-01-01

    Full Text Available In this study, the slippers being the most effective on the performance of swash plate type axial piston pumps and motors, which is a good example of hydrodynamic-hydrostatic bearing applications, have been investigated. With respect to this, having derived the viscous moment loss, viscous flow leakage loss and power loss equations, the variations of these parameters under different operating conditions have been examined experimentally.

  7. Virtual Refrigerant Mass Flow and Power Sensors for Variable-Speed Compressors

    OpenAIRE

    Kim, Woohyun; Braun, James E.

    2012-01-01

    The use of variable-speed compressors in heat pumps and air conditioners has increased in recent years in order to improve comfort and energy efficiency. At the same time, there is a trend towards embedding more sensors in this type of equipment to facilitate real-time energy monitoring and diagnostics. Although compressor mass flow rate and power consumption are useful indices for performance monitoring and diagnostics, they are expensive to measure. The virtual variable-speed compressor sen...

  8. Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

    Science.gov (United States)

    Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

    2017-04-01

    In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

  9. Radial basis function neural network for power system load-flow

    International Nuclear Information System (INIS)

    Karami, A.; Mohammadi, M.S.

    2008-01-01

    This paper presents a method for solving the load-flow problem of the electric power systems using radial basis function (RBF) neural network with a fast hybrid training method. The main idea is that some operating conditions (values) are needed to solve the set of non-linear algebraic equations of load-flow by employing an iterative numerical technique. Therefore, we may view the outputs of a load-flow program as functions of the operating conditions. Indeed, we are faced with a function approximation problem and this can be done by an RBF neural network. The proposed approach has been successfully applied to the 10-machine and 39-bus New England test system. In addition, this method has been compared with that of a multi-layer perceptron (MLP) neural network model. The simulation results show that the RBF neural network is a simpler method to implement and requires less training time to converge than the MLP neural network. (author)

  10. Full Vehicle Vibration and Noise Analysis Based on Substructure Power Flow

    Directory of Open Access Journals (Sweden)

    Zhien Liu

    2017-01-01

    Full Text Available Combining substructure and power flow theory, in this paper an external program is written to control MSC. Nastran solution process and the substructure frequency response are also formulated accordingly. Based on a simple vehicle model, characteristics of vibration, noise, and power flow are studied, respectively. After being compared with the result of conventional FEM (finite element method, the new method is confirmed to be feasible. When it comes to a vehicle with the problem of low-frequency noise, finite element models of substructures for vehicle body and chassis are established, respectively. In addition, substructure power flow method is also employed to examine the transfer characteristics of multidimensional vibration energy for the whole vehicle system. By virtue of the adjustment stiffness of drive shaft support and bushes at rear suspension lower arm, the vehicle interior noise is decreased by about 3 dB when the engine speed is near 1050 rpm and 1650 rpm in experiment. At the same time, this method can increase the computation efficiency by 78%, 38%, and 98% when it comes to the optimization of chassis structure, body structure, and vibration isolation components, respectively.

  11. Power flow as a complement to statistical energy analysis and finite element analysis

    Science.gov (United States)

    Cuschieri, J. M.

    1987-01-01

    Present methods of analysis of the structural response and the structure-borne transmission of vibrational energy use either finite element (FE) techniques or statistical energy analysis (SEA) methods. The FE methods are a very useful tool at low frequencies where the number of resonances involved in the analysis is rather small. On the other hand SEA methods can predict with acceptable accuracy the response and energy transmission between coupled structures at relatively high frequencies where the structural modal density is high and a statistical approach is the appropriate solution. In the mid-frequency range, a relatively large number of resonances exist which make finite element method too costly. On the other hand SEA methods can only predict an average level form. In this mid-frequency range a possible alternative is to use power flow techniques, where the input and flow of vibrational energy to excited and coupled structural components can be expressed in terms of input and transfer mobilities. This power flow technique can be extended from low to high frequencies and this can be integrated with established FE models at low frequencies and SEA models at high frequencies to form a verification of the method. This method of structural analysis using power flo and mobility methods, and its integration with SEA and FE analysis is applied to the case of two thin beams joined together at right angles.

  12. Particle Swarm Optimization with Various Inertia Weight Variants for Optimal Power Flow Solution

    Directory of Open Access Journals (Sweden)

    Prabha Umapathy

    2010-01-01

    Full Text Available This paper proposes an efficient method to solve the optimal power flow problem in power systems using Particle Swarm Optimization (PSO. The objective of the proposed method is to find the steady-state operating point which minimizes the fuel cost, while maintaining an acceptable system performance in terms of limits on generator power, line flow, and voltage. Three different inertia weights, a constant inertia weight (CIW, a time-varying inertia weight (TVIW, and global-local best inertia weight (GLbestIW, are considered with the particle swarm optimization algorithm to analyze the impact of inertia weight on the performance of PSO algorithm. The PSO algorithm is simulated for each of the method individually. It is observed that the PSO algorithm with the proposed inertia weight yields better results, both in terms of optimal solution and faster convergence. The proposed method has been tested on the standard IEEE 30 bus test system to prove its efficacy. The algorithm is computationally faster, in terms of the number of load flows executed, and provides better results than other heuristic techniques.

  13. Hydraulic Darrieus turbines efficiency for free fluid flow conditions versus power farms conditions

    Energy Technology Data Exchange (ETDEWEB)

    Antheaume, Sylvain [Electricite de France, Recherche et Developpement, Laboratoire National d' Hydraulique et Environnement, 6 Quai Watier, 78400 Chatou (France); Maitre, Thierry; Achard, Jean-Luc [Laboratoire des Ecoulements Geophysiques et Industriels, BP 53, 38041 Grenoble (France)

    2008-10-15

    The present study deals with the efficiency of cross flow water current turbine for free stream conditions versus power farm conditions. In the first part, a single turbine for free fluid flow conditions is considered. The simulations are carried out with a new in house code which couples a Navier-Stokes computation of the outer flow field with a description of the inner flow field around the turbine. The latter is based on experimental results of a Darrieus wind turbine in an unbounded domain. This code is applied for the description of a hydraulic turbine. In the second part, the interest of piling up several turbines on the same axis of rotation to make a tower is investigated. Not only is it profitable because only one alternator is needed but the simulations demonstrate the advantage of the tower configuration for the efficiency. The tower is then inserted into a cluster of several lined up towers which makes a barge. Simulations show that the average barge efficiency rises as the distance between towers is decreased and as the number of towers is increased within the row. Thereby, the efficiency of a single isolated turbine is greatly increased when set both into a tower and into a cluster of several towers corresponding to possible power farm arrangements. (author)

  14. Groundwater flow modeling focused on the Fukushima Daiichi Nuclear Power Plant Site

    International Nuclear Information System (INIS)

    Saegusa, Hiromitsu; Onoe, Hironori; Kohashi, Akio; Watanabe, Masahisa

    2015-01-01

    Fukushima Daiichi nuclear power plant of Tokyo Electric Power Company is facing contaminated water issues in the aftermath of the Great East Japan Earthquake on March 11, 2011. The amount of contaminated water is continuously increasing due to groundwater leakage into the underground part of reactor and turbine buildings. Therefore, it is important to understand the groundwater flow conditions at the site and to predict the impact of countermeasures taken for isolating groundwater from the source of the contamination, i.e. the reactor buildings. Installations, such as of land-side and sea-side impermeable walls have been planned as countermeasures. In this study, groundwater flow modeling has been performed to estimate the response of groundwater flow conditions to the countermeasures. From the modeling, groundwater recharge and discharge areas, major groundwater flow direction, inflow rate into underground part of the buildings, and changes in response to implementation of the countermeasures could be reasonably estimated. The results indicate that the countermeasures will decrease the volume of inflow into the underground part of the buildings. This means that the countermeasures will be effective in reducing the discharge volume of contaminated groundwater to ocean. (author)

  15. Degradation of TBC Systems in Environments Relevant to Advanced Gas Turbines for IGCC Systems

    Science.gov (United States)

    Bohna, Nathaniel Allan

    Plasma sprayed (PS) thermal barrier coatings (TBCs) are used to provide thermal insulation for the hottest components in gas turbines. Zirconia stabilized with 7wt% yttria (7YSZ) is the most common ceramic top coat used for turbine blades. The 7YSZ coating can be degraded by the buildup of fly-ash deposits which can arise from the fuel source (coal/biomass) used in the combustion process in gas turbines. Fly-ash from the integrated gasification combined cycle (IGCC) process can result from coal-based syngas and also from ambient air which passes through the system. TBCs are also exposed to harsh gas environments containing CO2, SO2, and steam. As presented in this thesis, degradation from the combined effects of fly-ash and harsh gas atmosphere can severely limit TBC lifetimes. It is well established that degradation at very high temperatures (≥1250°C) from deposits consisting of the oxides CaO-MgO-Al2O3-SiO 2 results from extensive liquid silicate infiltration into the porous top coat of the YSZ. This infiltration causes early failure resulting from chemical and/or mechanical damage to the ceramic layer. Damage resulting from liquid infiltration, however, is not typically considered at relatively lower temperatures around 1100°C because liquid silicates would not be expected to form from the oxides in the deposit. A key focus of this study is to assess the mode and extent of TBC degradation at 1100°C in cases when some amount of liquid forms owing to the presence of K2SO4 as a minor ash constituent. Two types of liquid infiltrations are observed depending on the principal oxide (i.e., CaO or SiO2) in the deposit. The degradation is primarily the result of mechanical damage, which results from infiltration caused by the interaction of liquid K2SO4 with either the CaO or SiO2. The TBCs used in this work are representative of commonly used coatings used in the hottest sections of land-based gas turbines. The specimens consist of 7YSZ top coats deposited on

  16. Experimental study of the transition from forced to natural circulation in EBR-II at low power and flow

    International Nuclear Information System (INIS)

    Gillette, J.L.; Singer, R.M.; Tokar, J.V.; Sullivan, J.E.

    1979-01-01

    A series of tests have been conducted in EBR-II which studied the dynamics of the transition from forced to natural circulation flow in a liquid-metal-cooled fast breeder reactor (LMFBR). Each test was initiated by abruptly tripping an electromagnetic pump which supplies 5 to 6% of the normal full operational primary flow rate. The ensuing flow coast-down reached a minimum value after which the flow increased as natural circulation was established. The effects of secondary system flow through the intermediate heat exchanger and reactor decay power level on the minimum in-core flow rates and maximum in-core temperatures were examined

  17. Ultrasonic meters in the feedwater flow to recover thermal power in the reactor of nuclear power plant of Laguna Verde U1 and U2

    International Nuclear Information System (INIS)

    Tijerina S, F.

    2008-01-01

    The engineers in nuclear power plants BWRs and PWRs based on the development of the ultrasonic technology for the measurement of the mass, volumetric flow, density and temperature in fluids, have applied this technology in two primary targets approved by the NRC: the use for the recovery of thermal power in the reactor and/or to be able to realize an increase of thermal power licensed in a 2% (MUR) by 1OCFR50 Appendix K. The present article mentions the current problem in the measurement of the feedwater flow with Venturi meters, which affects that the thermal balance of reactor BWRs or PWRs this underestimated. One in broad strokes describes the application of the ultrasonic technology for the ultrasonic measurement in the flow of the feedwater system of the reactor and power to recover thermal power of the reactor. One is to the methodology developed in CFE for a calibration of the temperature transmitters of RTD's and the methodology for a calibration of the venturi flow transmitters using ultrasonic measurement. Are show the measurements in the feedwater of reactor of the temperature with RTD's and ultrasonic measurement, as well as the flow with the venturi and the ultrasonic measurement operating the reactor to the 100% of nominal thermal power, before and after the calibration of the temperature transmitters and flow. Finally, is a plan to be able to realize a recovery of thermal power of the reactor, showing as carrying out their estimations. As a result of the application of ultrasonic technology in the feedwater of reactor BWR-5 in Laguna Verde, in the Unit 1 cycle 13 it was recover an equivalent energy to a thermal power of 25 MWt in the reactor and an exit electrical power of 6 M We in the turbogenerator. Also in the Unit 2 cycle 10 it was recover an equivalent energy to a thermal power of 40 MWt in the reactor and an exit electrical power of 16 M We in the turbogenerator. (Author)

  18. Improvement of Power Flow Calculation with Optimization Factor Based on Current Injection Method

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2014-01-01

    Full Text Available This paper presents an improvement in power flow calculation based on current injection method by introducing optimization factor. In the method proposed by this paper, the PQ buses are represented by current mismatches while the PV buses are represented by power mismatches. It is different from the representations in conventional current injection power flow equations. By using the combined power and current injection mismatches method, the number of the equations required can be decreased to only one for each PV bus. The optimization factor is used to improve the iteration process and to ensure the effectiveness of the improved method proposed when the system is ill-conditioned. To verify the effectiveness of the method, the IEEE test systems are tested by conventional current injection method and the improved method proposed separately. Then the results are compared. The comparisons show that the optimization factor improves the convergence character effectively, especially that when the system is at high loading level and R/X ratio, the iteration number is one or two times less than the conventional current injection method. When the overloading condition of the system is serious, the iteration number in this paper appears 4 times less than the conventional current injection method.

  19. Design of Distributed Controllers Seeking Optimal Power Flow Solutions Under Communication Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano; Simonetto, Andrea; Dhople, Sairaj

    2016-12-29

    This paper focuses on power distribution networks featuring inverter-interfaced distributed energy resources (DERs), and develops feedback controllers that drive the DER output powers to solutions of time-varying AC optimal power flow (OPF) problems. Control synthesis is grounded on primal-dual-type methods for regularized Lagrangian functions, as well as linear approximations of the AC power-flow equations. Convergence and OPF-solution-tracking capabilities are established while acknowledging: i) communication-packet losses, and ii) partial updates of control signals. The latter case is particularly relevant since it enables asynchronous operation of the controllers where DER setpoints are updated at a fast time scale based on local voltage measurements, and information on the network state is utilized if and when available, based on communication constraints. As an application, the paper considers distribution systems with high photovoltaic integration, and demonstrates that the proposed framework provides fast voltage-regulation capabilities, while enabling the near real-time pursuit of solutions of AC OPF problems.

  20. Game-theoretic control of PHEV charging with power flow analysis

    Directory of Open Access Journals (Sweden)

    Yuan Liu

    2016-03-01

    Full Text Available Due to an ever-increasing market penetration of plug-in hybrid electric vehicles (PHEVs, the charging demand is expected to become a main determinant of the load in future distribution systems. In this paper, we investigate the problem of controlling in-home charging of PHEVs to accomplish peak load shifting while maximizing the revenue of the distribution service provider (DSP and PHEV owners. A leader-follower game model is proposed to characterize the preference and revenue expectation of PHEV owners and DSP, respectively. The follower (PHEV owner decides when to start charging based on the pricing schedule provided by the leader (DSP. The DSP can incentivize the charging of PHEV owners to avoid system peak load. The costs associated with power distribution, line loss, and voltage regulation are incorporated in the game model via power flow analysis. Based on a linear approximation of the power flow equations, the solution of sub-game perfect Nash equilibrium (SPNE is obtained. A case study is performed based on the IEEE 13-bus test feeder and realistic PHEV charging statistics, and the results demonstrate that our proposed PHEV charging control scheme can significantly improve the power quality in distribution systems by reducing the peak load and voltage fluctuations.

  1. An Efficacious Multi-Objective Fuzzy Linear Programming Approach for Optimal Power Flow Considering Distributed Generation.

    Science.gov (United States)

    Warid, Warid; Hizam, Hashim; Mariun, Norman; Abdul-Wahab, Noor Izzri

    2016-01-01

    This paper proposes a new formulation for the multi-objective optimal power flow (MOOPF) problem for meshed power networks considering distributed generation. An efficacious multi-objective fuzzy linear programming optimization (MFLP) algorithm is proposed to solve the aforementioned problem with and without considering the distributed generation (DG) effect. A variant combination of objectives is considered for simultaneous optimization, including power loss, voltage stability, and shunt capacitors MVAR reserve. Fuzzy membership functions for these objectives are designed with extreme targets, whereas the inequality constraints are treated as hard constraints. The multi-objective fuzzy optimal power flow (OPF) formulation was converted into a crisp OPF in a successive linear programming (SLP) framework and solved using an efficient interior point method (IPM). To test the efficacy of the proposed approach, simulations are performed on the IEEE 30-busand IEEE 118-bus test systems. The MFLP optimization is solved for several optimization cases. The obtained results are compared with those presented in the literature. A unique solution with a high satisfaction for the assigned targets is gained. Results demonstrate the effectiveness of the proposed MFLP technique in terms of solution optimality and rapid convergence. Moreover, the results indicate that using the optimal DG location with the MFLP algorithm provides the solution with the highest quality.

  2. REAL TIME PULVERISED COAL FLOW SOFT SENSOR FOR THERMAL POWER PLANTS USING EVOLUTIONARY COMPUTATION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    B. Raja Singh

    2015-01-01

    Full Text Available Pulverised coal preparation system (Coal mills is the heart of coal-fired power plants. The complex nature of a milling process, together with the complex interactions between coal quality and mill conditions, would lead to immense difficulties for obtaining an effective mathematical model of the milling process. In this paper, vertical spindle coal mills (bowl mill that are widely used in coal-fired power plants, is considered for the model development and its pulverised fuel flow rate is computed using the model. For the steady state coal mill model development, plant measurements such as air-flow rate, differential pressure across mill etc., are considered as inputs/outputs. The mathematical model is derived from analysis of energy, heat and mass balances. An Evolutionary computation technique is adopted to identify the unknown model parameters using on-line plant data. Validation results indicate that this model is accurate enough to represent the whole process of steady state coal mill dynamics. This coal mill model is being implemented on-line in a 210 MW thermal power plant and the results obtained are compared with plant data. The model is found accurate and robust that will work better in power plants for system monitoring. Therefore, the model can be used for online monitoring, fault detection, and control to improve the efficiency of combustion.

  3. Modeling of a District Heating System and Optimal Heat-Power Flow

    Directory of Open Access Journals (Sweden)

    Wentao Yang

    2018-04-01

    Full Text Available With ever-growing interconnections of various kinds of energy sources, the coupling between a power distribution system (PDS and a district heating system (DHS has been progressively intensified. Thus, it is becoming more and more important to take the PDS and the DHS as a whole in energy flow analysis. Given this background, a steady state model of DHS is first presented with hydraulic and thermal sub-models included. Structurally, the presented DHS model is composed of three major parts, i.e., the straight pipe, four kinds of local pipes, and the radiator. The impacts of pipeline parameters and the environment temperature on heat losses and pressure losses are then examined. The term “heat-power flow” is next defined, and the optimal heat-power flow (OHPF model formulated as a quadratic planning problem, in which the objective is to minimize energy losses, including the heat losses and active power losses, and both the operational constraints of PDS and DHS are respected. The developed OHPF model is solved by the well-established IPOPT (Interior Point OPTimizer commercial solver, which is based on the YALMIP/MATLAB toolbox. Finally, two sample systems are served for demonstrating the characteristics of the proposed models.

  4. Design of Distributed Controllers Seeking Optimal Power Flow Solutions under Communication Constraints: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano; Simonetto, Andrea; Dhople, Sairaj

    2016-12-01

    This paper focuses on power distribution networks featuring inverter-interfaced distributed energy resources (DERs), and develops feedback controllers that drive the DER output powers to solutions of time-varying AC optimal power flow (OPF) problems. Control synthesis is grounded on primal-dual-type methods for regularized Lagrangian functions, as well as linear approximations of the AC power-flow equations. Convergence and OPF-solution-tracking capabilities are established while acknowledging: i) communication-packet losses, and ii) partial updates of control signals. The latter case is particularly relevant since it enables asynchronous operation of the controllers where DER setpoints are updated at a fast time scale based on local voltage measurements, and information on the network state is utilized if and when available, based on communication constraints. As an application, the paper considers distribution systems with high photovoltaic integration, and demonstrates that the proposed framework provides fast voltage-regulation capabilities, while enabling the near real-time pursuit of solutions of AC OPF problems.

  5. Pinon Pine power project nears start-up

    Energy Technology Data Exchange (ETDEWEB)

    Tatar, G.A. [Sierra Pacific Power Co., Reno, NV (United States); Gonzalez, M. [Foster Wheeler USA Corp., Clinton, NJ (United States); Mathur, G.K. [M.W. Kellogg Co., Houston, TX (United States)

    1997-12-31

    The IGCC facility being built by Sierra Pacific Power Company (SPPCo) at their Tracy Station in Nevada is one of three IGCC facilities being cost-shared by the US Department of Energy (DOE) under their Clean Coal Technology Program. The specific technology to be demonstrated in SPPCo`s Round Four Project, known as the Pinon Pine IGCC Project, includes the KRW air blown pressurized fluidized bed gasification process with hot gas cleanup coupled with a combined cycle facility based on a new GE 6FA gas turbine. Construction of the 100 MW IGCC facility began in February 1995 and the first firing of the gas turbine occurred as scheduled on August 15, 1996 with natural gas. Mechanical completion of the gasifier and other outstanding work is due in January 1997. Following the startup of the plant, the project will enter a 42 month operating and testing period during which low sulfur western and high sulfur eastern or midwestern coals will be processed.

  6. Solution of wind integrated thermal generation system for environmental optimal power flow using hybrid algorithm

    Directory of Open Access Journals (Sweden)

    Ambarish Panda

    2016-09-01

    Full Text Available A new evolutionary hybrid algorithm (HA has been proposed in this work for environmental optimal power flow (EOPF problem. The EOPF problem has been formulated in a nonlinear constrained multi objective optimization framework. Considering the intermittency of available wind power a cost model of the wind and thermal generation system is developed. Suitably formed objective function considering the operational cost, cost of emission, real power loss and cost of installation of FACTS devices for maintaining a stable voltage in the system has been optimized with HA and compared with particle swarm optimization algorithm (PSOA to prove its effectiveness. All the simulations are carried out in MATLAB/SIMULINK environment taking IEEE30 bus as the test system.

  7. A Modified Load Flow Algorithm in Power Systems with Alternative Energy Sources

    International Nuclear Information System (INIS)

    Contreras, D.L.; Cañedo, J.M.

    2017-01-01

    In this paper an algorithm for calculating the steady state of electrical networks including wind and photovoltaic generation is presented. The wind generators considered are; asynchronous (squirrel cage and doubly fed) and synchronous generators using permanent magnets. The proposed algorithm is based on the formulation of nodal power injections that is solved with the modified Newton Raphson technique in its polar formulation using complex matrices notation. Each power injection of wind and photovoltaic generators is calculated independently in each iteration according to its particular mathematical model, which is generally non-linear. Results are presented with a 30-node test system. The computation time of the proposed algorithm is compared with the conventional methodology to include alternative energy sources in power flows studies. (author)

  8. Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

    Science.gov (United States)

    Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

    2015-12-01

    To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Power Disturbances Close to Hydrodynamic Instability in Natural Circulation Two-Phase Flow

    Energy Technology Data Exchange (ETDEWEB)

    Mathisen, R P; Eklind, O

    1967-07-15

    In certain boiling reactor designs high positive void coefficients could exist and under certain circumstances cause instability. Control systems may therefore be desired. In such a controlled reactor there could remain superimposed low frequency power oscillations of some magnitude. The object of the current experiments in SKALVAN was to examine whether or not such slow oscillations could influence the hydrodynamic stability limit of the individual boiling channels. While operating the loop close to the threshold of hydrodynamic instability, the power was pulsed in the boiling channel. The pulse widths had a lower limit of 0.65 sec due to the contactor time constant. The square wave power oscillation amplitude {delta}Q/Q was 12.2 %, and the interval T between the pulses was varied in the range 0 < T{sub 0}/T < 0. 5 where T{sub 0} was the mass flow oscillation period. The corresponding mass flow oscillations remained damped for all disturbance periods which were examined. With minimum test section inlet restrictions the power level at instability was much lower than that at burnout conditions. At higher restrictions these phenomena occurred at approximately equivalent power levels. The experiments with minimum inlet restrictions were also performed beyond the instability threshold. In this case it was possible to exceed the nominal burnout point temporarily by 5 per cent or more for periods of the order of magnitude 1 second. Even now the boiling channel conditions were not so severely affected that the burnout detectors tripped, and the power disturbances caused low frequency modulated wave trains.

  10. Second Order Cone Programming (SOCP) Relaxation Based Optimal Power Flow with Hybrid VSC-HVDC Transmission and Active Distribution Networks

    DEFF Research Database (Denmark)

    Ding, Tao; Li, Cheng; Yang, Yongheng

    2017-01-01

    The detailed topology of renewable resource bases may have the impact on the optimal power flow of the VSC-HVDC transmission network. To address this issue, this paper develops an optimal power flow with the hybrid VSC-HVDC transmission and active distribution networks to optimally schedule...... the generation output and voltage regulation of both networks, which leads to a non-convex programming model. Furthermore, the non-convex power flow equations are based on the Second Order Cone Programming (SOCP) relaxation approach. Thus, the proposed model can be relaxed to a SOCP that can be tractably solved...

  11. Increasing power generation in horizontal axis wind turbines using optimized flow control

    Science.gov (United States)

    Cooney, John A., Jr.

    In order to effectively realize future goals for wind energy, the efficiency of wind turbines must increase beyond existing technology. One direct method for achieving increased efficiency is by improving the individual power generation characteristics of horizontal axis wind turbines. The potential for additional improvement by traditional approaches is diminishing rapidly however. As a result, a research program was undertaken to assess the potential of using distributed flow control to increase power generation. The overall objective was the development of validated aerodynamic simulations and flow control approaches to improve wind turbine power generation characteristics. BEM analysis was conducted for a general set of wind turbine models encompassing last, current, and next generation designs. This analysis indicated that rotor lift control applied in Region II of the turbine power curve would produce a notable increase in annual power generated. This was achieved by optimizing induction factors along the rotor blade for maximum power generation. In order to demonstrate this approach and other advanced concepts, the University of Notre Dame established the Laboratory for Enhanced Wind Energy Design (eWiND). This initiative includes a fully instrumented meteorological tower and two pitch-controlled wind turbines. The wind turbines are representative in their design and operation to larger multi-megawatt turbines, but of a scale that allows rotors to be easily instrumented and replaced to explore new design concepts. Baseline data detailing typical site conditions and turbine operation is presented. To realize optimized performance, lift control systems were designed and evaluated in CFD simulations coupled with shape optimization tools. These were integrated into a systematic design methodology involving BEM simulations, CFD simulations and shape optimization, and selected experimental validation. To refine and illustrate the proposed design methodology, a

  12. Nuclear power plant life management: flow accelerated corrosion and chemical control. Application to Embalse Nuclear power plant

    International Nuclear Information System (INIS)

    Chocron, Mauricio; Saucedo, Ramona E.; Sainz, Ricardo A.; Ovando, Luis E.

    2006-01-01

    The chemistry of a water-steam cycle is one of the main aspects of the Plant Life Management of a Nuclear Power Plant and it is important for the preservation, efficiency and availability of the whole system. In that sense this aspect has to be prioritized in any study whose aim is the life extension of the plant. In particular, the flow-assisted -corrosion or FAC is a problem that worldwide has been considered important due to the piping wall thinning that in some occasions has led to severe accidents. The FAC phenomena is not easy to be interpreted and addressed although nowadays there are some accepted models to understand and predict sensitive areas of the cycle. The objectives of the present paper have been: a) The construction of an integrated code that involves all the aspects that have influence on FAC, i.e., materials, composition, geometry, temperature and flow rate, quality, chemistry, etc.; b) Establish or adapting current models to the circuit of Embalse PHWR NPP; c) Identify new locations for inspection and wall thickness measurement in order to predict residual life; d) Compare different chemistries and e) handle large sets of inspection data. Among the results, new lines have been incorporated to the inspection schedule of the 2005' programmed outage. Also, the evaluation is part of the PLIM-PLEX programme at Embalse-N.A.S.A. in collaboration with C.N.E.A. is being carried out. (author)

  13. Valuing flexibility: The case of an Integrated Gasification Combined Cycle power plant

    International Nuclear Information System (INIS)

    Abadie, Luis M.; Chamorro, Jose M.

    2008-01-01

    In this paper we analyze the choice between two technologies for producing electricity. In particular, the firm has to decide whether and when to invest either in a Natural Gas Combined Cycle (NGCC) power plant or in an Integrated Gasification Combined Cycle (IGCC) power plant, which may burn either coal or natural gas. Instead of assuming that fuel prices follow standard geometric Brownian motions, here they are assumed to show mean reversion, specifically to follow an inhomogeneous geometric Brownian motion. First we consider the opportunity to invest in a NGCC power plant. We derive the optimal investment rule as a function of natural gas price and the remaining life of the right to invest. In addition, the analytical solution for a perpetual option to invest is obtained. Then we turn to the IGCC power plant. We analyse the valuation of an operating plant when there are switching costs between modes of operation, and the choice of the best operation mode. This serves as an input to evaluate the option to invest in this plant. Finally we derive the value of an opportunity to invest either in a NGCC or IGCC power plant, i.e. to choose between an inflexible and a flexible technology, respectively. Depending on the opportunity's time to maturity, we derive the pairs of coal and gas prices for which it is optimal to invest in NGCC, in IGCC, or simply not to invest. Numerical computations involve the use of one- and two-dimensional binomial lattices that support a mean-reverting process for coal and gas prices. Basic parameter values are taken from an actual IGCC power plant currently in operation. Sensitivity of some results with respect to the underlying stochastic process for fuel price is also checked

  14. Air-Flow-Driven Triboelectric Nanogenerators for Self-Powered Real-Time Respiratory Monitoring.

    Science.gov (United States)

    Wang, Meng; Zhang, Jiahao; Tang, Yingjie; Li, Jun; Zhang, Baosen; Liang, Erjun; Mao, Yanchao; Wang, Xudong

    2018-06-04

    Respiration is one of the most important vital signs of humans, and respiratory monitoring plays an important role in physical health management. A low-cost and convenient real-time respiratory monitoring system is extremely desirable. In this work, we demonstrated an air-flow-driven triboelectric nanogenerator (TENG) for self-powered real-time respiratory monitoring by converting mechanical energy of human respiration into electric output signals. The operation of the TENG was based on the air-flow-driven vibration of a flexible nanostructured polytetrafluoroethylene (n-PTFE) thin film in an acrylic tube. This TENG can generate distinct real-time electric signals when exposed to the air flow from different breath behaviors. It was also found that the accumulative charge transferred in breath sensing corresponds well to the total volume of air exchanged during the respiration process. Based on this TENG device, an intelligent wireless respiratory monitoring and alert system was further developed, which used the TENG signal to directly trigger a wireless alarm or dial a cell phone to provide timely alerts in response to breath behavior changes. This research offers a promising solution for developing self-powered real-time respiratory monitoring devices.

  15. User-friendly Tool for Power Flow Analysis and Distributed Generation Optimisation in Radial Distribution Networks

    Directory of Open Access Journals (Sweden)

    M. F. Akorede

    2017-06-01

    Full Text Available The intent of power distribution companies (DISCOs is to deliver electric power to their customers in an efficient and reliable manner – with minimal energy loss cost. One major way to minimise power loss on a given power system is to install distributed generation (DG units on the distribution networks. However, to maximise benefits, it is highly crucial for a DISCO to ensure that these DG units are of optimal size and sited in the best locations on the network. This paper gives an overview of a software package developed in this study, called Power System Analysis and DG Optimisation Tool (PFADOT. The main purpose of the graphical user interface-based package is to guide a DISCO in finding the optimal size and location for DG placement in radial distribution networks. The package, which is also suitable for load flow analysis, employs the GUI feature of MATLAB. Three objective functions are formulated into a single optimisation problem and solved with fuzzy genetic algorithm to simultaneously obtain DG optimal size and location. The accuracy and reliability of the developed tool was validated using several radial test systems, and the results obtained are evaluated against the existing similar package cited in the literature, which are impressive and computationally efficient.

  16. Operation manual for the core flow test loop zone power-supply controller

    Energy Technology Data Exchange (ETDEWEB)

    Harper, R.E.

    1981-11-01

    The core flow test loop, which is part of the Gas-Cooled Fast Breeder Reactor Program (GCFR) at ORNL, is a high-pressure, high-temperature, out-of-reactor helium circulation system that is being constructed to permit study of the performance at steady-state and transient conditions of simulated segments of core assemblies for a GCFR demonstration plant. The simulated core segments, which are divided into zones, contain electrical heating elements to simulate the heat generated by fission. To control the power which is applied to a zone, a novel multitapped transformer and zone power control system have been designed and built which satisfy stringent design criteria. The controller can match power output to demand to within better than +-1% over a 900:1 dynamic range and perform full-power transients within 1 s. The power is applied in such a way as to minimize the electromagnetic interference at the bandwidth of the loop instrumentation, and the controller incorporates several error detection techniques, making it inherently fail-safe. The operation manual describes the specifications, operating instructions, error detection capabilities, error recovery, troubleshooting, calibration and QA procedures, and maintenance requirements. Also included are sections on the theory of operation, circuitry description, and a complete set of schematics.

  17. Cost-optimal power system extension under flow-based market coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hagspiel, Simeon; Jaegemann, Cosima; Lindenberger, Dietmar [Koeln Univ. (Germany). Energiewirtschaftliches Inst.; Brown, Tom; Cherevatskiy, Stanislav; Troester, Eckehard [Energynautics GmbH, Langen (Germany)

    2013-05-15

    Electricity market models, implemented as dynamic programming problems, have been applied widely to identify possible pathways towards a cost-optimal and low carbon electricity system. However, the joint optimization of generation and transmission remains challenging, mainly due to the fact that different characteristics and rules apply to commercial and physical exchanges of electricity in meshed networks. This paper presents a methodology that allows to optimize power generation and transmission infrastructures jointly through an iterative approach based on power transfer distribution factors (PTDFs). As PTDFs are linear representations of the physical load flow equations, they can be implemented in a linear programming environment suitable for large scale problems. The algorithm iteratively updates PTDFs when grid infrastructures are modified due to cost-optimal extension and thus yields an optimal solution with a consistent representation of physical load flows. The method is first demonstrated on a simplified three-node model where it is found to be robust and convergent. It is then applied to the European power system in order to find its cost-optimal development under the prescription of strongly decreasing CO{sub 2} emissions until 2050.

  18. Comparison of Comet Enflow and VA One Acoustic-to-Structure Power Flow Predictions

    Science.gov (United States)

    Grosveld, Ferdinand W.; Schiller, Noah H.; Cabell, Randolph H.

    2010-01-01

    Comet Enflow is a commercially available, high frequency vibroacoustic analysis software based on the Energy Finite Element Analysis (EFEA). In this method the same finite element mesh used for structural and acoustic analysis can be employed for the high frequency solutions. Comet Enflow is being validated for a floor-equipped composite cylinder by comparing the EFEA vibroacoustic response predictions with Statistical Energy Analysis (SEA) results from the commercial software program VA One from ESI Group. Early in this program a number of discrepancies became apparent in the Enflow predicted response for the power flow from an acoustic space to a structural subsystem. The power flow anomalies were studied for a simple cubic, a rectangular and a cylindrical structural model connected to an acoustic cavity. The current investigation focuses on three specific discrepancies between the Comet Enflow and the VA One predictions: the Enflow power transmission coefficient relative to the VA One coupling loss factor; the importance of the accuracy of the acoustic modal density formulation used within Enflow; and the recommended use of fast solvers in Comet Enflow. The frequency region of interest for this study covers the one-third octave bands with center frequencies from 16 Hz to 4000 Hz.

  19. UEDGE Simulations for Power and Particle Flow Analysis of FRC Rocket

    Science.gov (United States)

    Zheng, Fred; Evans, Eugene S.; McGreivy, Nick; Kaptanoglu, Alan; Izacard, Olivier; Cohen, Samuel A.

    2017-10-01

    The field-reversed configuration (FRC) is under consideration for use in a direct fusion drive (DFD) rocket propulsion system for future space missions. To achieve a rocket configuration, the FRC is embedded within an asymmetric magnetic mirror, in which one end is closed and contains a gas box, and the other end is open and incorporates a magnetic nozzle. Neutral deuterium is injected into the gas box, and flows through the scrape-off layer (SOL) around the core plasma and out the magnetic nozzle, both cooling the core and serving as propellant. Previous studies have examined a range of operating conditions for the SOL of a DFD using UEDGE, a 2D fluid code; discrepancies on the order of 5% were found during the analysis of overall power balance. This work extends the analysis of the previously-studied SOL geometry by updating boundary conditions and conducting a detailed study of power and particle flows within the simulation with the goals of modeling electrical power generation instead of thrust and achieving higher specific impulse. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466 and Princeton Environmental Institute.

  20. Analytical analysis of heat transfer and pumping power of laminar nanofluid developing flow in microchannels

    International Nuclear Information System (INIS)

    Mital, Manu

    2013-01-01

    Thermal management issues are limiting barriers to high density electronics packaging and miniaturization. Liquid cooling using micro and mini channels is an attractive alternative to large and bulky aluminum or copper heat sinks. These channels can be integrated directly into a chip or a heat spreader, and cooling can be further enhanced using nanofluids (liquid solutions with dispersed nanometer-sized particles) due to their enhanced heat transfer effects reported in literature. The goals of this study are to evaluate heat transfer improvement of a nanofluid heat sink with developing laminar flow forced convection, taking into account the pumping power penalty. The phrase heat transfer enhancement ratio (HTR) is used to denote the ratio of average heat transfer coefficient of nanofluid to water at the same pumping power. The proposed model uses semi-empirical correlations to calculate nanofluid thermophysical properties. The predictions of the model are found to be in good agreement with experimental studies. The validated model is used to identify important design variables (Reynolds number, volume fraction and particle size) related to thermal and flow characteristics of the microchannel heat sink with nanofluids. Statistical analysis of the model showed that the volume fraction is the most significant factor impacting the HTR, followed by the particle diameter. The impact of the Reynolds number and other interaction terms is relatively weak. The HTR is maximized at smallest possible particle diameter (since smaller particles improve heat transfer but do not impact pumping power). Then, for a given Reynolds number, an optimal value of volume fraction can be obtained to maximize HTR. The overall aim is to present results that would be useful for understanding and optimal design of microchannel heat sinks with nanofluid flow. - Highlights: ► Validated model is used to investigate heat transfer and pumping power in nanofluids. ► Particles improve heat transfer

  1. Power Flow Analysis for Low-Voltage AC and DC Microgrids Considering Droop Control and Virtual Impedance

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay Kumar; Savaghebi, Mehdi

    2017-01-01

    In the low-voltage (LV) ac microgrids (MGs), with a relatively high R/X ratio, virtual impedance is usually adopted to improve the performance of droop control applied to distributed generators (DGs). At the same time, LV dc MG using virtual impedance as droop control is emerging without adequate...... power flow studies. In this paper, power flow analyses for both ac and dc MGs are formulated and implemented. The mathematical models for both types of MGs considering the concept of virtual impedance are used to be in conformity with the practical control of the DGs. As a result, calculation accuracy...... is improved for both ac and dc MG power flow analyses, comparing with previous methods without considering virtual impedance. Case studies are conducted to verify the proposed power flow analyses in terms of convergence and accuracy. Investigation of the impact to the system of internal control parameters...

  2. 3D NUMERICAL STUDY OF FLOW IN A SOLAR CHIMNEY POWER PLANT SYSTEM

    Directory of Open Access Journals (Sweden)

    TAHAR TAYEBI

    2015-12-01

    Full Text Available Heat transfer process and fluid flow in a Solar Chimney Power Plant System (SCPPS are investigated numerically. As simulation object we use the Spanish prototype plant. The calculative model and boundary conditions in calculation are introduced. Boussinesq model was chosen in the natural convection processus, Discrete Ordinate radiation model was employed for radiation. The principal factors that influence on the performance of the Solar Chimney have been analysed. The effects on the flow of the Solar Chimney which caused by solar radiation intensity have been simulated. The calculated results are compared and are approximately equivalent to the relative experimental data of the Manzanares prototype. It can be concluded that the temperature difference between the inlet and outlet of collector, as well as the air velocity in the collector of the system, is increase with the increase of solar radiation intensity and the pressure throughout system is negative value.

  3. The complex approach to the flow accelerated cracking in Czech nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ruscak, M; Splichal, K; Kaplan, J [Nuclear Research Institute, Rez (Czech Republic)

    1994-12-31

    The paper shows the approach of NRI to the problems of flow accelerated cracking of the secondary piping in VVER nuclear power plants. The utilization of the CHECMATE family codes is described in the framework of other activities to support the prediction and evaluation of damage. The code allows the effects of parameters such as temperature, geometry, mass transport conditions, void fraction and material composition to be assessed. The influence of exact measurement of chromium content is discussed. 2 refs., 6 figs., 1 tab.

  4. The complex approach to the flow accelerated cracking in Czech nuclear power plants

    International Nuclear Information System (INIS)

    Ruscak, M.; Splichal, K.; Kaplan, J.

    1994-01-01

    The paper shows the approach of NRI to the problems of flow accelerated cracking of the secondary piping in VVER nuclear power plants. The utilization of the CHECMATE family codes is described in the framework of other activities to support the prediction and evaluation of damage. The code allows the effects of parameters such as temperature, geometry, mass transport conditions, void fraction and material composition to be assessed. The influence of exact measurement of chromium content is discussed. 2 refs., 6 figs., 1 tab

  5. Flow accelerated corrosion and life management of the secondary circuit of the Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Chocron, Mauricio; La Gamma, Ana M.; Fernandez, Narciso; Moyano, Ricardo; Schiersmann, Christian; Ovando, Luis E.; Sainz, Ricardo A.; Keitelman, Alberto

    2003-01-01

    Flow accelerated corrosion is a matter of concern in secondary circuits of nuclear power plants as well as in fossil fired plants. It contributes to the piping wall thinning and to the corrosion products transport to the steam generators. Because it is a generalized corrosion phenomena, could address to extensive failures. In that sense the plants conduct extensive programs of surveillance of piping degradation. Because the problem involves many variables like alloys, water chemistry and hydrodynamics several models have been proposed in the literature. In the present paper the variables have been organized in a spreadsheet which allows the calculation of normalized risk factors. (author)

  6. Multidimensional flow of radioactive gases through the soil surrounding an underground nuclear power plant

    International Nuclear Information System (INIS)

    Dinkelacker, A.

    1980-01-01

    In connection with the underground siting of nuclear power plants the spreading of radioactive gases that are released into the soil coverage after a hypothetical accident is investigated. A physical model is presented that includes the isothermal one- and two-component flow of ideal gases through an inhomogeneous porous medium on the basis of Darcy's law. Based on this model a computer code has been developed that permits the calculation of transient pressure and concentration distributions in inhomogeneous porous media in one to three dimensions, as well as the determination of retention times. (orig.) [de

  7. On accuracy of the wave finite element predictions of wavenumbers and power flow: A benchmark problem

    Science.gov (United States)

    Søe-Knudsen, Alf; Sorokin, Sergey

    2011-06-01

    This rapid communication is concerned with justification of the 'rule of thumb', which is well known to the community of users of the finite element (FE) method in dynamics, for the accuracy assessment of the wave finite element (WFE) method. An explicit formula linking the size of a window in the dispersion diagram, where the WFE method is trustworthy, with the coarseness of a FE mesh employed is derived. It is obtained by the comparison of the exact Pochhammer-Chree solution for an elastic rod having the circular cross-section with its WFE approximations. It is shown that the WFE power flow predictions are also valid within this window.

  8. Robust optimization-based DC optimal power flow for managing wind generation uncertainty

    Science.gov (United States)

    Boonchuay, Chanwit; Tomsovic, Kevin; Li, Fangxing; Ongsakul, Weerakorn

    2012-11-01

    Integrating wind generation into the wider grid causes a number of challenges to traditional power system operation. Given the relatively large wind forecast errors, congestion management tools based on optimal power flow (OPF) need to be improved. In this paper, a robust optimization (RO)-based DCOPF is proposed to determine the optimal generation dispatch and locational marginal prices (LMPs) for a day-ahead competitive electricity market considering the risk of dispatch cost variation. The basic concept is to use the dispatch to hedge against the possibility of reduced or increased wind generation. The proposed RO-based DCOPF is compared with a stochastic non-linear programming (SNP) approach on a modified PJM 5-bus system. Primary test results show that the proposed DCOPF model can provide lower dispatch cost than the SNP approach.

  9. EFFECT OF POWER SUPPLY AND DUTY CONTROL IN CRANKCASE FLOW (CRANKCASE PRESSURE PORT OF ECV

    Directory of Open Access Journals (Sweden)

    MD. IQBAL MAHMUD

    2016-06-01

    Full Text Available The electromagnetic control valve (ECV operated by solenoid in the external variable compressor with the swash plate type is the rising phenomenon. ECV controls the air conditioning compressor for automobile on the basis of the input signal of the pulse width modulation (PWM that supplied from the external controller. PWM technique is used to encode the information for transmission; its main use is to allow the control of the power to be supplied to electrical devices, especially to inertial loads. The mechanism changes the swash plate angle inside the compressor by increasing or reducing the pressure of swash plate chamber by use of the functions of different pressure port within the ECV. Increasing and reducing the swash plate angle finally depends on the solenoid force acting on the rate of supply of current. This research paper investigates the effect of power supply and duty control during the crankcase flowing at Pc pressure port of ECV.

  10. Traveling wave linear accelerator with RF power flow outside of accelerating cavities

    Science.gov (United States)

    Dolgashev, Valery A.

    2016-06-28

    A high power RF traveling wave accelerator structure includes a symmetric RF feed, an input matching cell coupled to the symmetric RF feed, a sequence of regular accelerating cavities coupled to the input matching cell at an input beam pipe end of the sequence, one or more waveguides parallel to and coupled to the sequence of regular accelerating cavities, an output matching cell coupled to the sequence of regular accelerating cavities at an output beam pipe end of the sequence, and output waveguide circuit or RF loads coupled to the output matching cell. Each of the regular accelerating cavities has a nose cone that cuts off field propagating into the beam pipe and therefore all power flows in a traveling wave along the structure in the waveguide.

  11. Dynamic population artificial bee colony algorithm for multi-objective optimal power flow

    Directory of Open Access Journals (Sweden)

    Man Ding

    2017-03-01

    Full Text Available This paper proposes a novel artificial bee colony algorithm with dynamic population (ABC-DP, which synergizes the idea of extended life-cycle evolving model to balance the exploration and exploitation tradeoff. The proposed ABC-DP is a more bee-colony-realistic model that the bee can reproduce and die dynamically throughout the foraging process and population size varies as the algorithm runs. ABC-DP is then used for solving the optimal power flow (OPF problem in power systems that considers the cost, loss, and emission impacts as the objective functions. The 30-bus IEEE test system is presented to illustrate the application of the proposed algorithm. The simulation results, which are also compared to nondominated sorting genetic algorithm II (NSGAII and multi-objective ABC (MOABC, are presented to illustrate the effectiveness and robustness of the proposed method.

  12. Robustness analysis of complex networks with power decentralization strategy via flow-sensitive centrality against cascading failures

    Science.gov (United States)

    Guo, Wenzhang; Wang, Hao; Wu, Zhengping

    2018-03-01

    Most existing cascading failure mitigation strategy of power grids based on complex network ignores the impact of electrical characteristics on dynamic performance. In this paper, the robustness of the power grid under a power decentralization strategy is analysed through cascading failure simulation based on AC flow theory. The flow-sensitive (FS) centrality is introduced by integrating topological features and electrical properties to help determine the siting of the generation nodes. The simulation results of the IEEE-bus systems show that the flow-sensitive centrality method is a more stable and accurate approach and can enhance the robustness of the network remarkably. Through the study of the optimal flow-sensitive centrality selection for different networks, we find that the robustness of the network with obvious small-world effect depends more on contribution of the generation nodes detected by community structure, otherwise, contribution of the generation nodes with important influence on power flow is more critical. In addition, community structure plays a significant role in balancing the power flow distribution and further slowing the propagation of failures. These results are useful in power grid planning and cascading failure prevention.

  13. Three-Phase AC Optimal Power Flow Based Distribution Locational Marginal Price: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui; Zhang, Yingchen

    2017-05-17

    Designing market mechanisms for electricity distribution systems has been a hot topic due to the increased presence of smart loads and distributed energy resources (DERs) in distribution systems. The distribution locational marginal pricing (DLMP) methodology is one of the real-time pricing methods to enable such market mechanisms and provide economic incentives to active market participants. Determining the DLMP is challenging due to high power losses, the voltage volatility, and the phase imbalance in distribution systems. Existing DC Optimal Power Flow (OPF) approaches are unable to model power losses and the reactive power, while single-phase AC OPF methods cannot capture the phase imbalance. To address these challenges, in this paper, a three-phase AC OPF based approach is developed to define and calculate DLMP accurately. The DLMP is modeled as the marginal cost to serve an incremental unit of demand at a specific phase at a certain bus, and is calculated using the Lagrange multipliers in the three-phase AC OPF formulation. Extensive case studies have been conducted to understand the impact of system losses and the phase imbalance on DLMPs as well as the potential benefits of flexible resources.

  14. Load flow analysis for determining the location of NPP power distribution in West Kalimantan

    International Nuclear Information System (INIS)

    Citra Candranurani; Rizki Finnansyah Setya Budi; Sahala M Lumbanraja

    2015-01-01

    Electricity crisis condition happened in West Kalimantan (Kalbar) as a result of power plant capacity almost equal to the peak load. The system will experience a shortfall if there are plants that not operating and do not have reserve. The policy of electricity planning until 2022 is replacing diesel power plant with steam power plant. For long-term planning is required the role of new and renewable energy in order to reduce dependency on fossil fuel consumption, such as NPP utilization. The purpose of this study was to determine the optimum location of the NPP power distribution in order to prepare electricity infrastructure. Load flow calculation in this study using ETAP 12.5 software. NPP is planned to supply base load, so the optimum capacity factor is above 80 %. The result show that there are three location where NPP can generate over 80 % of its capacity, namely: Mempawah Substation, Singkawang Substation, and Sambas Substation. The most optimum located in Mempawah Substation with capacity factor 83.5 %. The location of the three Substation are onshore and in line with one requirement for NPP construction, namely: the availability of cooling water. (author)

  15. Application of the discounted value flows method in production cost calculations for Czechoslovak nuclear power plants

    International Nuclear Information System (INIS)

    Majer, P.

    1990-01-01

    The fundamentals are outlined of the discounted value flows method, which is used in industrial countries for calculating the specific electricity production costs. Actual calculations were performed for the first two units of the Temelin nuclear power plant. All costs associated with the construction, operation and decommissioning of this nuclear power plant were taken into account. With a high degree of certainty, the specific production costs of the Temelin nuclear power plant will lie within the range of 0.32 to 0.36 CSK/kWh. Nearly all results of the sensitivity analysis performed for the possible changes in the input values fall within this range. An increase in the interest rate to above 8% is an exception; this, however, can be regarded as rather improbable on a long-term basis. Sensitivity analysis gave evidence that the results of the electricity production cost calculations for the Temelin nuclear power plant can be considered sufficiently stable. (Z.M.). 7 figs., 2 tabs., 14 refs

  16. Power Flow Calculation for Weakly Meshed Distribution Networks with Multiple DGs Based on Generalized Chain-table Storage Structure

    DEFF Research Database (Denmark)

    Chen, Shuheng; Hu, Weihao; Chen, Zhe

    2014-01-01

    Based on generalized chain-table storage structure (GCTSS), a novel power flow method is proposed, which can be used to solve the power flow of weakly meshed distribution networks with multiple distributed generators (DGs). GCTSS is designed based on chain-table technology and its target is to de......Based on generalized chain-table storage structure (GCTSS), a novel power flow method is proposed, which can be used to solve the power flow of weakly meshed distribution networks with multiple distributed generators (DGs). GCTSS is designed based on chain-table technology and its target...... is to describe the topology of radial distribution networks with a clear logic and a small memory size. The strategies of compensating the equivalent currents of break-point branches and the reactive power outputs of PV-type DGs are presented on the basis of superposition theorem. Their formulations...... are simplified to be the final multi-variable linear functions. Furthermore, an accelerating factor is applied to the outer-layer reactive power compensation for improving the convergence procedure. Finally, the proposed power flow method is performed in program language VC++ 6.0, and numerical tests have been...

  17. Optimal power flow with optimal placement TCSC device on 500 kV Java-Bali electrical power system using genetic Algorithm-Taguchi method

    Science.gov (United States)

    Apribowo, Chico Hermanu Brillianto; Ibrahim, Muhammad Hamka; Wicaksono, F. X. Rian

    2018-02-01

    The growing burden of the load and the complexity of the power system has had an impact on the need for optimization of power system operation. Optimal power flow (OPF) with optimal location placement and rating of thyristor controlled series capacitor (TCSC) is an effective solution used to determine the economic cost of operating the plant and regulate the power flow in the power system. The purpose of this study is to minimize the total cost of generation by placing the location and the optimal rating of TCSC using genetic algorithm-design of experiment techniques (GA-DOE). Simulation on Java-Bali system 500 kV with the amount of TCSC used by 5 compensator, the proposed method can reduce the generation cost by 0.89% compared to OPF without using TCSC.

  18. Reactor design and operation strategies for a large-scale packed-bed CLC power plant with coal syngas

    NARCIS (Netherlands)

    Spallina, V.; Chiesa, P.; Martelli, E; Gallucci, F.; Romano, M.C.; Lozza, G.; Sint Annaland, van M.

    2015-01-01

    This paper deals with the design and operation strategies of dynamically operated packed-bed reactors (PBRs) of a chemical looping combustion (CLC) system included in an integrated gasification combined cycle (IGCC) for electric power generation with low CO2 emission from coal. The CLC reactors,

  19. Cogeneration (hydrogen and electrical power) using the Texaco Gasification Power Systems (TGPS) technology

    International Nuclear Information System (INIS)

    Gardner, J.

    1994-01-01

    The information herein presents preliminary technical and cost data for an actual case study using Texaco Gasification Power Systems (TGPS) technology, incorporated as part of an overall refinery upgrade project. This study is based on gasification of asphalt and vacuum residue (see Table 1, feedstock properties) to produce hydrogen plus carbon monoxide (synthesis gas) for the ultimate production of high purity hydrogen and power at a major refinery in Eastern Europe. A hydrogen production of 101,000 Nm 3 /hr (9.1 tons/hr) at 99.9 (wt.%) purity plus 50 MW (net) power slated to be used by the refinery was considered for this study. Figure I shows a block diagram depicting the general refinery configuration upgrade as envisioned by the owner operator; included in the configuration as shown in the shaded area is the TGPS plant. Figure II shows a block flow diagram depicting the TGPS unit and its battery limits as defined for this project. The technology best suited to meet the demand for clean and efficient electric power generation and hydrogen production is the Texaco Gasification Power Systems (TGPS) process. This technology is based upon Texaco's proprietary gasification technology which is well proven with over 40 years of gasification experience. There are currently 37 operating units in the world today which have licensed the Texaco gasification process technology, with another 12 in design/construction. Total synthesis gas (hydrogen + carbon monoxide) production capacity is over 2,8 billion standard cubic feet per day. The TGPS, which is basically the Integrated Gasification Combined Cycle (IGCC) based upon the Texaco gasification technology, was developed by combining and integrating gasification with power generation facilities. (author). 3 figs., 9 tabs., 4 refs

  20. Thermal, mechanical and fluid flow aspects of the high power beam dump for FRIB

    Energy Technology Data Exchange (ETDEWEB)

    Avilov, Mikhail [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Aaron, Adam [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831 (United States); Amroussia, Aida [Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824 (United States); Bergez, Wladimir [Institut de Mecanique des Fluides de Toulouse, Toulouse University, CNRS, Allée Camille Soula, 31400 Toulouse (France); Boehlert, Carl [Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824 (United States); Burgess, Thomas; Carroll, Adam [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831 (United States); Colin, Catherine [Institut de Mecanique des Fluides de Toulouse, Toulouse University, CNRS, Allée Camille Soula, 31400 Toulouse (France); Durantel, Florent [Centre des recherches sur les Ions, les Materiaux et la Photonique (CIMAP) CEA-CNRS-ENSICAEN-UCN, BP 5133, 14070 CAEN CEDEX 5 (France); Ferrante, Paride; Fourmeau, Tiffany [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Graves, Van [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831 (United States); Grygiel, Clara [Centre des recherches sur les Ions, les Materiaux et la Photonique (CIMAP) CEA-CNRS-ENSICAEN-UCN, BP 5133, 14070 CAEN CEDEX 5 (France); Kramer, Jacob [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Mittig, Wolfgang [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Monnet, Isabelle [Centre des recherches sur les Ions, les Materiaux et la Photonique (CIMAP) CEA-CNRS-ENSICAEN-UCN, BP 5133, 14070 CAEN CEDEX 5 (France); Patel, Harsh [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); and others

    2016-06-01

    The Facility for Rare Isotope Beams (FRIB) under construction at Michigan State University is based on a 400 kW heavy ion accelerator and uses in-flight production and separation to generate rare isotope beams. The first section of the fragment separator houses the rare isotope production target, and the primary beam dump to stop the unreacted primary beam. The experimental program will use 400 kW ion beams from {sup 16}O to {sup 238}U. After interaction with the production target, over 300 kW in remaining beam power must be absorbed by the beam dump. A rotating water-cooled thin-shell metal drum was chosen as the basic concept for the beam dump. Extensive thermal, mechanical and fluid flow analyses were performed to evaluate the effects of the high power density in the beam dump shell and in the water. Many properties were optimized simultaneously, such as shell temperature, mechanical strength, fatigue strength, and radiation resistance. Results of the analyses of the beam dump performance with different design options will be discussed. For example, it was found that a design modification to the initial water flow pattern resulted in a substantial increase in the wall heat transfer coefficient. A detailed evaluation of materials for the shell is in progress. The widely used titanium alloy, Ti–6Al–4V (wt%), is presently considered as the best candidate, and is the subject of specific tests, such as studies of performance under heavy ion irradiation.

  1. Genetic search for an optimal power flow solution from a high density cluster

    Energy Technology Data Exchange (ETDEWEB)

    Amarnath, R.V. [Hi-Tech College of Engineering and Technology, Hyderabad (India); Ramana, N.V. [JNTU College of Engineering, Jagityala (India)

    2008-07-01

    This paper proposed a novel method to solve optimal power flow (OPF) problems. The method is based on a genetic algorithm (GA) search from a High Density Cluster (GAHDC). The algorithm of the proposed method includes 3 stages, notably (1) a suboptimal solution is obtained via a conventional analytical method, (2) a high density cluster, which consists of other suboptimal data points from the first stage, is formed using a density-based cluster algorithm, and (3) a genetic algorithm based search is carried out for the exact optimal solution from a low population sized, high density cluster. The final optimal solution thoroughly satisfies the well defined fitness function. A standard IEEE 30-bus test system was considered for the simulation study. Numerical results were presented and compared with the results of other approaches. It was concluded that although there is not much difference in numerical values, the proposed method has the advantage of minimal computational effort and reduced CPU time. As such, the method would be suitable for online applications such as the present Optimal Power Flow problem. 24 refs., 2 tabs., 4 figs.

  2. A new quantum inspired chaotic artificial bee colony algorithm for optimal power flow problem

    International Nuclear Information System (INIS)

    Yuan, Xiaohui; Wang, Pengtao; Yuan, Yanbin; Huang, Yuehua; Zhang, Xiaopan

    2015-01-01

    Highlights: • Quantum theory is introduced to artificial bee colony algorithm (ABC) to increase population diversity. • A chaotic local search operator is used to enhance local search ability of ABC. • Quantum inspired chaotic ABC method (QCABC) is proposed to solve optimal power flow. • The feasibility and effectiveness of the proposed QCABC is verified by examples. - Abstract: This paper proposes a new artificial bee colony algorithm with quantum theory and the chaotic local search strategy (QCABC), and uses it to solve the optimal power flow (OPF) problem. Under the quantum computing theory, the QCABC algorithm encodes each individual with quantum bits to form a corresponding quantum bit string. By determining each quantum bits value, we can get the value of the individual. After the scout bee stage of the artificial bee colony algorithm, we begin the chaotic local search in the vicinity of the best individual found so far. Finally, the quantum rotation gate is used to process each quantum bit so that all individuals can update toward the direction of the best individual. The QCABC algorithm is carried out to deal with the OPF problem in the IEEE 30-bus and IEEE 118-bus standard test systems. The results of the QCABC algorithm are compared with other algorithms (artificial bee colony algorithm, genetic algorithm, particle swarm optimization algorithm). The comparison shows that the QCABC algorithm can effectively solve the OPF problem and it can get the better optimal results than those of other algorithms

  3. Hybrid Approximate Dynamic Programming Approach for Dynamic Optimal Energy Flow in the Integrated Gas and Power Systems

    DEFF Research Database (Denmark)

    Shuai, Hang; Ai, Xiaomeng; Wen, Jinyu

    2017-01-01

    This paper proposes a hybrid approximate dynamic programming (ADP) approach for the multiple time-period optimal power flow in integrated gas and power systems. ADP successively solves Bellman's equation to make decisions according to the current state of the system. So, the updated near future...

  4. Investigation of analytical methods in thermal stratification analysis. Evaluation of flow rates through flow holes for normal and scram conditions of 40% power operation with AQUA code

    International Nuclear Information System (INIS)

    Doi, Yoshihiro; Muramatsu, Toshiharu

    1997-08-01

    Thermal stratification phenomena are observed in an upper plenum of liquid metal fast breeder reactors (LMFBRs) under reactor scram conditions, which give rise to thermal stress on structural components. Therefore it is important to evaluate characteristics of phenomena in the design of the internal structure in an LMFBR plenum. To evaluate flow rates through flow holes of the prototype fast breeder reactor, MONJU, numerical analyses were carried out with AQUA code for normal and scram conditions with 40% power operation. Through comparison of analysis results and measured temperature, thermal stratification phenomena in 300 second period after the scram was evaluated. Flow rate through the upper flow holes, the lower flow holes and annular gap between the inner barrel and the reactor vessel were evaluated with the measured temperature and the analysis results individually. (J.P.N.)

  5. Dual turbine power plant and a reheat steam bypass flow control system for use therein

    International Nuclear Information System (INIS)

    Braytenbah, A.S.; Jaegtnes, K.O.

    1977-01-01

    An electric power plant having dual turbine-generators connected to a steam source that includes a high temperature gas cooled nuclear reactor is described. Each turbine comprises a high pressure portion operated by superheat steam and an intermediate-low pressure portion operated by reheat steam; a bypass line is connected across each turbine portion to permit a desired minimum flow of steam from the source at times when the combined flow of steam through the turbine is less than the minimum. Coolant gas is propelled through the reactor by a circulator which is driven by an auxiliary turbine which uses steam exhausted from the high pressure portions and their bypass lines. The pressure of the reheat steam is controlled by a single proportional-plus-integral controller which governs the steam flow through the bypass lines associated with the intermediate-low pressure portions. At times when the controller is not in use its output signal is limited to a value that permits an unbiased response when pressure control is resumed, as in event of a turbine trip. 25 claims, 2 figures

  6. Thermodynamics, maximum power, and the dynamics of preferential river flow structures at the continental scale

    Directory of Open Access Journals (Sweden)

    A. Kleidon

    2013-01-01

    Full Text Available The organization of drainage basins shows some reproducible phenomena, as exemplified by self-similar fractal river network structures and typical scaling laws, and these have been related to energetic optimization principles, such as minimization of stream power, minimum energy expenditure or maximum "access". Here we describe the organization and dynamics of drainage systems using thermodynamics, focusing on the generation, dissipation and transfer of free energy associated with river flow and sediment transport. We argue that the organization of drainage basins reflects the fundamental tendency of natural systems to deplete driving gradients as fast as possible through the maximization of free energy generation, thereby accelerating the dynamics of the system. This effectively results in the maximization of sediment export to deplete topographic gradients as fast as possible and potentially involves large-scale feedbacks to continental uplift. We illustrate this thermodynamic description with a set of three highly simplified models related to water and sediment flow and describe the mechanisms and feedbacks involved in the evolution and dynamics of the associated structures. We close by discussing how this thermodynamic perspective is consistent with previous approaches and the implications that such a thermodynamic description has for the understanding and prediction of sub-grid scale organization of drainage systems and preferential flow structures in general.

  7. Application of flow-controllable accumulator and performance analysis in Korean Nuclear Power Plants

    International Nuclear Information System (INIS)

    Jung, Byung-Ryul; Lee, Un-Chul

    1997-01-01

    The Korean Yonggwang Nuclear Power Plants 3 ampersand 4(YGN 3 ampersand 4) are the two-loop pressurized water reactor (PWR) nuclear steam supply systems, rated at 2,815 MW(thermal). They incorporate the safety injection system (SIS) consisting of the two high pressure (HPSI) pumps, two low pressure safety injection (LPSI) pumps, and four accumulators. The SIS is two headered arrangements, each to four cold legs injection (CLI) type which provides cooling to the core in the highly unlikely event of a loss-of-coolant accident (LOCA). In the current SIS, the LPSI pumps automatically start during a LOCA, and also provide the residual heat removal capability during the shutdown cooling. This paper presents the feasibility of the removal of the LPSI from the existing SIS with minor system changes, including the increase up to four in the HPSI pumps, direct vessel injection(DVI), and the flow-controllable accumulators. A double-ended rupture of one of the four cold legs in the YGN 3 ampersand 4 was simulated using RELAP5/MOD3.1 to determine the feasibility of the application of this new SIS design to the current nuclear power plants. As a result, the calculated reflooding peak cladding surface temperature(PCT) was comparable to that of original base calculation, and the downcomer and the core collapsed liquid level during reflooding were also comparable to those in the current safety system design. This large break, cold-leg LOCA analysis addresses the reflooding capability without credit for a LPSI pump system and the applicability of the new flow-controllable accumulator. Also this analysis confirms that the combination of new flow-controllable accumulators, DVI and the increased HPSI pumps maintain the peak cladding temperature below the prescribed limits. 14 refs., 4 figs., 3 tabs

  8. Conversion of Aircraft Dual-flow Turbojet into Peak Power Plant

    Directory of Open Access Journals (Sweden)

    G. A. Shafikov

    2017-01-01

    Full Text Available The paper is aimed at considering the aircraft engine conversion into peak or short-used energy unit, which is relevant for the task of developing the northern regions of the Russian Federation. The three-shaft turbojet engine with a twelve-stage compressor and a four-stage turbine is adopted as an aircraft engine under consideration. The afterburner with a block of jet nozzles is removed from the gas generator module, and a heating chamber is set at the outlet of the by-pass duct to raise electric power of engine and not complicate the construction by the presence of a mixing chamber. In addition, the heating chamber serves to equalize the total pressure and flow temperature in the section before the free turbine and allows the use of a short adapter between the gas generator module and the free turbine, which reduces the loss of total pressure. Then a free turbine and a diffuser with an exhaust device are installed. The output shaft of the power turbine is connected by means of a coupling to an alternating current (a. c. generator or other special load.To find the parameters of the plant, a calculation was made in which the initial data were taken, namely a gas temperature in front of the turbine of 1530 K (the gas temperature in front of the turbine is reduced by 100 K in order to prolong the engine life; therefore, the gas temperature before the turbine was 1630 K; air flow of 364 kg/s; bypass ratio of 1.36 (the ratio of the air flow passing through the bypass duct to the air flow entering the core. As a result, it consumes 0.296 kg / (kWh (fuel-aviation kerosene and a power capacity of 78.5 MW. For the received value of capacity the ТЗФП-80-2У3 a. c. electric generator has been chosen as the load. As a result, the power plant, equipped with a converted engine and electric generator, has an electric power of 77.3 MW and an efficiency of 27.8%.To assess the effect of introduced preheating chamber on the parameters of the gas turbine

  9. Using wind speed from a blade-mounted flow sensor for power and load assessment on modern wind turbines

    DEFF Research Database (Denmark)

    Pedersen, Mads M.; Larsen, Torben J.; Madsen, Helge Aa

    2017-01-01

    In this paper an alternative method to evaluate power performance and loads on wind turbines using a blade-mounted flow sensor is investigated. The hypothesis is that the wind speed measured at the blades has a high correlation with the power and loads such that a power or load assessment can...... be performed from a few hours or days of measurements. In the present study a blade-mounted five-hole pitot tube is used as the flow sensor as an alternative to the conventional approach, where the reference wind speed is either measured at a nearby met mast or on the nacelle using lidar technology or cup...... anemometers. From the flow sensor measurements, an accurate estimate of the wind speed at the rotor plane can be obtained. This wind speed is disturbed by the presence of the wind turbine, and it is therefore different from the free-flow wind speed. However, the recorded wind speed has a high correlation...

  10. An improved power flow method based on extended chain-table storage structure for distribution network with PV nodes

    DEFF Research Database (Denmark)

    Chen, Shuheng; Wang, Xiongfei; Su, Chi

    2014-01-01

    with a reduced memory size. The voltage error of each PV node is adjusted by a reactive power adjusting strategy. The adjusting strategy is based on a multi-variable linear function with an accelerating factor. Finally, this new improved power flow method is realized by the software system developed in VC......Based on an extended chain-table storage structure, an improved power flow method is presented, which can be applied to a distribution network with multi PV nodes. The extended chain-table storage structure is designed on the basis of address-pointer technology describing the radial topology...... and the corresponding case study has been done. The experimental data and the further analysis have proved that this method can calculate the power flow of a distribution network with multi PV nodes precisely and fast. © 2014 IEEE....

  11. Power flow modeling of Back-to-Back STATCOM: Comprehensive simulation studies including PV curves and PQ circles

    Directory of Open Access Journals (Sweden)

    Ahmet Mete Vural

    2017-09-01

    Full Text Available Power flow study in a power network embedded with FACTS device requires effort in program coding. Moreover, Newton-Raphson method should be modified by embedding injected power components into the algorithm. In this study, we have proposed a method for modeling of one of the newest FACTS concepts in power flow study without program coding or modification of existing Newton-Raphson algorithm. Real and reactive power injections for each voltage source converter of Back-to-Back Static Synchronous Compensator (BtB-STATCOM are PI regulated to their desired steady-state values. With this respect, reactive power injection of each voltage source converter as well as real power transfer among them can be assigned as control constraint. Operating losses are also taken into account in the proposed modeling approach. Furthermore, proposed model can be easily modified for the modeling of conventional STATCOM having only one voltage source converter or two STATCOMs operating independently. The proposed modeling approach is verified in PSCAD through a number of simulation scenarios in BtB-STATCOM and STATCOM embedded power systems, namely 1-Machine 4-Bus system and 3-Machine 7-Bus system. PV curves of local buses compensated by BtB-STATCOM and STATCOM are presented and compared. Steady-state performance of BtB-STATCOM and STATCOM is also compared in power flow handling.

  12. Future carbon regulations and current investments in alternative coal-fired power plant technologies

    International Nuclear Information System (INIS)

    Sekar, Ram C.; Parsons, John E.; Herzog, Howard J.; Jacoby, Henry D.

    2007-01-01

    We analyze how uncertain future US carbon regulations shape the current choice of the type of power plant to build. Our focus is on two coal-fired technologies, pulverized coal (PC) and integrated coal gasification combined cycle technology (IGCC). The PC technology is cheapest-assuming there is no need to control carbon emissions. The IGCC technology may be cheaper if carbon must be captured. Since power plants last many years and future regulations are uncertain, a US electric utility faces a standard decision under uncertainty. A company will confront the range of possible outcomes, assigning its best estimate of the probability of each scenario, averaging the results and determining the power plant technology with the lowest possible cost inclusive of expected future carbon related costs, whether those costs be in the form of emissions charges paid or capital expenditures for retrofitting to capture carbon. If the company assigns high probability to no regulation or to less stringent regulation of carbon, then it makes sense for it to build the PC plant. But if it assigns sufficient probability to scenarios with more stringent regulation, then the IGCC technology is warranted. We provide some useful benchmarks for possible future regulation and show how these relate back to the relative costs of the two technologies and the optimal technology choice. Few of the policy proposals widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. However, recent carbon prices in the European Emissions Trading System are higher than these benchmarks. If it is any guide to possible future penalties for emissions in the US, then current investment in the IGCC technology is warranted. Of course, other factors need to be factored into the decision as well

  13. Power Flow Distribution Strategy for Improved Power Electronics Energy Efficiency in Battery Storage Systems: Development and Implementation in a Utility-Scale System

    Directory of Open Access Journals (Sweden)

    Michael Schimpe

    2018-03-01

    Full Text Available Utility-scale battery storage systems typically consist of multiple smaller units contributing to the overall power dispatch of the system. Herein, the power distribution among these units is analyzed and optimized to operate the system with increased energy efficiency. To improve the real-life storage operation, a holistic system model for battery storage systems has been developed that enables a calculation of the energy efficiency. A utility-scale Second-Life battery storage system with a capacity of 3.3 MWh/3 MW is operated and evaluated in this work. The system is in operation for the provision of primary control reserve in combination with intraday trading for controlling the battery state of charge. The simulation model is parameterized with the system data. Results show that losses in power electronics dominate. An operational strategy improving the energy efficiency through an optimized power flow distribution within the storage system is developed. The power flow distribution strategy is based on the reduction of the power electronics losses at no-load/partial-load by minimizing their in-operation time. The simulation derived power flow distribution strategy is implemented in the real-life storage system. Field-test measurements and analysis prove the functionality of the power flow distribution strategy and reveal the reduction of the energy throughput of the units by 7%, as well as a significant reduction of energy losses in the units by 24%. The cost savings for electricity over the system’s lifetime are approximated to 4.4% of its investment cost.

  14. Effect of Orifice Nozzle Design and Input Power on Two-Phase Flow and Mass Transfer Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hei Cheon [Chonnam Nat’l Univ., Gwangju (Korea, Republic of)

    2016-04-15

    It is necessary to investigate the input power as well as the mass transfer characteristics of the aeration process in order to improve the energy efficiency of an aerobic water treatment. The objective of this study is to experimentally investigate the effect of orifice nozzle design and input power on the flow and mass transfer characteristics of a vertical two-phase flow. The mass ratio, input power, volumetric mass transfer coefficient, and mass transfer efficiency were calculated using the measured data. It was found that as the input power increases the volumetric mass transfer coefficient increases, while the mass ratio and mass transfer efficiency decrease. The mass ratio, volumetric mass transfer coefficient, and mass transfer efficiency were higher for the orifice configuration with a smaller orifice nozzle area ratio. An empirical correlation was proposed to estimate the effect of mass ratio, input power, and Froude number on the volumetric mass transfer coefficient.

  15. Stabilization and control of tie-line power flow of microgrid including wind generation by distributed energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Molina, M.G.; Mercado, P.E. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste 1109, J5400ARL San Juan (Argentina)

    2010-06-15

    High penetration of wind generation in electrical microgrids causes fluctuations of tie-line power flow and significantly affects the power system operation. This can lead to severe problems, such as system frequency oscillations, and/or violations of power lines capability. With proper control, a distribution static synchronous compensator (DSTATCOM) integrated with superconducting magnetic energy storage (SMES) is able to significantly enhance the dynamic security of the power system. This paper proposes the use of a SMES system in combination with a DSTATCOM as effective distributed energy storage (DES) for stabilization and control of the tie-line power flow of microgrids incorporating wind generation. A new detailed model of the integrated DSTATCOM-SMES device is derived and a novel three-level control scheme is designed. The dynamic performance of the proposed control schemes is fully validated using MATLAB/Simulink. (author)

  16. A New Method for Simulating Power Flow Density Focused by a Silicon Lens Antenna Irradiated with Linearly Polarized THz Wave

    Directory of Open Access Journals (Sweden)

    Catur Apriono

    2015-08-01

    Full Text Available A terahertz system uses dielectric lens antennas for focusing and collimating beams of terahertz wave radiation. Linearly polarized terahertz wave radiation has been widely applied in the terahertz system. Therefore, an accurate method for analyzing the power flow density in the dielectric lens antenna irradiated with the linearly polarized terahertz wave radiation is important to design the terahertz systems. In optics, ray-tracing method has been used to calculate the power flow density by a number density of rays. In this study, we propose a method of ray-tracing combined with Fresnel’s transmission, including transmittance and polarization of the terahertz wave radiation to calculate power flow density in a Silicon lens antenna. We compare power flow density calculated by the proposed method with the regular ray-tracing method. When the Silicon lens antenna is irradiated with linearly polarized terahertz wave radiation, the proposed method calculates the power flow density more accurately than the regular ray-tracing.

  17. Operational measurements of stack flow rates in a nuclear power plant with ultrasonic anemometer

    International Nuclear Information System (INIS)

    Voelz, E.; Kirtzel, H.-J.; Ebenhoech, E.

    2003-01-01

    The calculation of the impact of radio nuclides within the surroundings of nuclear power stations requires quantitative measurements of the stack emission. As a standard method, propeller anemometers have been installed inside the stack, but due to the wear and tear of the moving parts in such conventional sensors the servicing and maintenance are costly and may cause restrictions in the operation of the stack. As an alternative to propeller anemometers ultrasonic sensors have been applied which employ no moving parts and are almost free of maintenance. Furthermore, any shifts in internal calibration parameters can be identified by the sensor electronics with on-line plausibility checks. The tests have proven that ultrasonic systems are able to measure adequately and reliably the flow inside the stack. (orig.)

  18. Development and comparision of techniques for estimating design basis flood flows for nuclear power plants

    International Nuclear Information System (INIS)

    1980-05-01

    Estimation of the design basis flood for Nuclear Power Plants can be carried out using either deterministic or stochastic techniques. Stochastic techniques, while widely used for the solution of a variety of hydrological and other problems, have not been used to date (1980) in connection with the estimation of design basis flood for NPP siting. This study compares the two techniques against one specific river site (Galt on the Grand River, Ontario). The study concludes that both techniques lead to comparable results , but that stochastic techniques have the advantage of extracting maximum information from available data and presenting the results (flood flow) as a continuous function of probability together with estimation of confidence limits. (author)

  19. Control device for the recycling flow rate in a nuclear power plant

    International Nuclear Information System (INIS)

    Tanigawa, Naoshi; Shida, Toichi.

    1983-01-01

    Purpose: To prevent the cavitation in a recycling pump even under the conditions where a recycling pump run-back is inhibited, thereby secure the safety of equipments. Constitution: An AND circuit is disposed to a recycling flow rate control system in a BWR type nuclear power plant that issues an output on the condition that a run-back signal is present together with a contact signal of a scoop pipe locking relay or a contact signal of a scoop pipe locking relay. Then, if a demand for the run-back operation of a nuclear reactor recycling pump is issued, the reactor recycling pump is forcedly tripped. Since the pump can always be tripped upon requirement of run-back even if there are some or other inhibitive factors, generation of the cavitation in recycling system equipments can be prevented thereby prevent the damages in the equipments. (Moriyama, K.)

  20. One Core Phase Shifting Transformer for Control of the Power Flow Distribution in Electric Networks

    Directory of Open Access Journals (Sweden)

    Golub I.V.

    2016-08-01

    Full Text Available This paper presents the variant of phase shifting transformer that is made, unlike from traditional technology, on the basis of only one magnetic core. The paper describes the methodology related to the analysis of operation modes of device and its components. Additionally it presents a mathematical model of device with determines the relationship between input and output electric quantities as well as own longitudinal and transverse parameters of an equivalent circuit of phase shifting transformer (PST. Proposed configuration of PST is interesting from an economic and operational consideration; enable continuous control of power flow distribution in electric networks as a result of regulation a phase shift angle between input and output voltages of device.