WorldWideScience

Sample records for reactive power management

  1. Reactive Power Management in Electric Power Systems

    African Journals Online (AJOL)

    (Ferranti effect) would limit the power transfer and the transmission range in the absence of any compensation measures. Journal of EAEA, Vol 14, 1997. In this paper, the management of the reactive power is explored with the aim of improving the quality and the reliability of the supply in the EELPA's interconnected system ...

  2. Reactive power management of power networks with wind generation

    CERN Document Server

    Amaris, Hortensia; Ortega, Carlos Alvarez

    2012-01-01

    As the energy sector shifts and changes to focus on renewable technologies, the optimization of wind power becomes a key practical issue. Reactive Power Management of Power Networks with Wind Generation brings into focus the development and application of advanced optimization techniques to the study, characterization, and assessment of voltage stability in power systems. Recent advances on reactive power management are reviewed with particular emphasis on the analysis and control of wind energy conversion systems and FACTS devices. Following an introduction, distinct chapters cover the 5 key

  3. Reactive power management and voltage control in deregulated power markets

    Science.gov (United States)

    Spangler, Robert G.

    The research that is the subject of this dissertation is about the management of reactive power and voltage support in the wholesale open access power markets in the United States (US). The purpose of this research is to place decisions about open access market structures, as they relate to reactive power and voltage control, on a logical and consistent economic basis, given the engineering needs of a commercial electric power system. An examination of the electricity markets operating in the US today reveals that current approaches to reactive power management and voltage support are extensions of those based on historical, regulated monopoly electric service. A case for change is built by first looking at the subject of reactive power from an engineering viewpoint and then from an economic perspective. Ultimately, a set of market rules for managing reactive power and voltage support is proposed. The proposal suggests that cost recovery for static and dynamic VARs is appropriately accomplished through the regulated transmission cost of service. Static VAR cost recovery should follow traditional rate recovery methodologies. In the case of dynamic VARs, this work provides a methodology based on the microeconomic theory of the firm for determining such cost. It further suggests that an operational strategy that reduces and limits the use of dynamic VARs, during normal operations, is appropriate. This latter point leads to an increase in the fixed cost of the transmission network but prevents price spikes and short supply situations from affecting, or being affected by, the reactive capability limitations associated with dynamic VARs supplied from synchronous generators. The rules are consistent with a market structure that includes competitive generation and their application will result in the communication of a clear understanding of the responsibilities, related to voltage control, of each type of market entity. In this sense, their application will contribute to

  4. Advanced Reactive Power Reserve Management Scheme to Enhance LVRT Capability

    Directory of Open Access Journals (Sweden)

    Hwanik Lee

    2017-10-01

    Full Text Available Abstract: To increase the utilization of wind power in the power system, grid integration standards have been proposed for the stable integration of large-scale wind power plants. In particular, fault-ride-through capability, especially Low-Voltage-Ride-Through (LVRT, has been emphasized, as it is related to tripping in wind farms. Therefore, this paper proposes the Wind power plant applicable-Effective Reactive power Reserve (Wa-ERPR, which combines both wind power plants and conventional generators at the Point of Interconnection (POI. The reactive power capability of the doubly-fed induction generator wind farm was considered to compute the total Wa-ERPR at the POI with reactive power capability of existing generators. By using the Wa-ERPR management algorithm, in case of a violation of the LVRT standards, the amount of reactive power compensation is computed using the Wa-ERPR management scheme. The proposed scheme calculates the Wa-ERPR and computes the required reactive power, reflecting the change of the system topology pre- and post-contingency, to satisfy the LVRT criterion when LVRT regulation is not satisfied at the POI. The static synchronous compensator (STATCOM with the capacity corresponding to calculated amount of reactive power through the Wa-ERPR management scheme is applied to the POI. Therefore, it is confirmed that the wind power plant satisfies the LVRT criteria by securing the appropriate reactive power at the POI, by applying of the proposed algorithm.

  5. Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

    DEFF Research Database (Denmark)

    Vlachogiannis, Ioannis (John)

    2009-01-01

    grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control......In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and "intelligent" components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power...... capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also...

  6. Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

    International Nuclear Information System (INIS)

    Vlachogiannis, John G.

    2009-01-01

    In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and 'intelligent' components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also consider more stochastic aspects such as variable grid's topology. Results of the proposed strategy obtained on the networks of IEEE 30-bus and IEEE 118-bus systems demonstrate the effectiveness of the proposed strategy.

  7. Agent-based reactive power management of power distribution networks with distributed energy generation

    International Nuclear Information System (INIS)

    Rahman, M.S.; Mahmud, M.A.; Oo, A.M.T.; Pota, H.R.; Hossain, M.J.

    2016-01-01

    Highlights: • A coordinated multi-agent system is proposed for reactive power management. • A linear quadratic regulator with a proportional integral controller is designed. • Proposed multi-agent scheme provides accurate estimation and control of the system. • Voltage stability is improved with proper power management for different scenarios. • Results obtained from the proposed scheme is compared to the traditional approach. - Abstract: In this paper, a new agent-based distributed reactive power management scheme is proposed to improve the voltage stability of energy distribution systems with distributed generation units. Three types of agents – distribution system agent, estimator agent, and control agent are developed within the multi-agent framework. The agents simultaneously coordinated their activities through the online information and energy flow. The overall achievement of the proposed scheme depends on the coordination between two tasks – (i) estimation of reactive power using voltage variation formula and (ii) necessary control actions to provide the estimated reactive power to the distribution networks through the distributed static synchronous compensators. A linear quadratic regulator with a proportional integrator is designed for the control agent in order to control the reactive component of the current and the DC voltage of the compensators. The performance of the proposed scheme is tested on a 10-bus power distribution network under various scenarios. The effectiveness is validated by comparing the proposed approach to the conventional proportional integral control approach. It is found that, the agent-based scheme provides excellent robust performance under various operating conditions of the power distribution network.

  8. Reactive Power Compensation Using an Energy Management System

    Science.gov (United States)

    2014-09-01

    compiled to VHDL code using Xilinx System Generator software [12], which is used by the FPGA to command the EMS. The FPGA development board is the middle...controller was implemented in the lab to correct iems because the EMS hardware currently does not have a sensor on the source current. Adding a...shown in Figure 13 as φsource changes over time. 20 The function of the power factor correction diagram shown in Figure 14 is to implement the power

  9. Optimal Control of Wind Farms for Coordinated TSO-DSO Reactive Power Management

    Directory of Open Access Journals (Sweden)

    David Sebastian Stock

    2018-01-01

    Full Text Available The growing importance of renewable generation connected to distribution grids requires an increased coordination between transmission system operators (TSOs and distribution system operators (DSOs for reactive power management. This work proposes a practical and effective interaction method based on sequential optimizations to evaluate the reactive flexibility potential of distribution networks and to dispatch them along with traditional synchronous generators, keeping to a minimum the information exchange. A modular optimal power flow (OPF tool featuring multi-objective optimization is developed for this purpose. The proposed method is evaluated for a model of a real German 110 kV grid with 1.6 GW of installed wind power capacity and a reduced order model of the surrounding transmission system. Simulations show the benefit of involving wind farms in reactive power support reducing losses both at distribution and transmission level. Different types of setpoints are investigated, showing the feasibility for the DSO to fulfill also individual voltage and reactive power targets over multiple connection points. Finally, some suggestions are presented to achieve a fair coordination, combining both TSO and DSO requirements.

  10. Distributed multi-agent scheme for reactive power management with renewable energy

    International Nuclear Information System (INIS)

    Rahman, M.S.; Mahmud, M.A.; Pota, H.R.; Hossain, M.J.

    2014-01-01

    Highlights: • A distributed multi-agent scheme is proposed to enhance the dynamic voltage stability. • A control agent is designed where control actions are performed through PI controller. • Proposed scheme is compared with the conventional approach with DSTATCOM. • Proposed scheme adapts the capability of estimation and control under various operating conditions. - Abstract: This paper presents a new distributed multi-agent scheme for reactive power management in smart coordinated distribution networks with renewable energy sources (RESs) to enhance the dynamic voltage stability, which is mainly based on controlling distributed static synchronous compensators (DSTATCOMs). The proposed control scheme is incorporated in a multi-agent framework where the intelligent agents simultaneously coordinate with each other and represent various physical models to provide information and energy flow among different physical processes. The reactive power is estimated from the topology of distribution networks and with this information, necessary control actions are performed through the proposed proportional integral (PI) controller. The performance of the proposed scheme is evaluated on a 8-bus distribution network under various operating conditions. The performance of the proposed scheme is validated through simulation results and these results are compared to that of conventional PI-based DSTATCOM control scheme. From simulation results, it is found that the distributed MAS provides excellence performance for improving voltage profiles by managing reactive power in a smarter way

  11. Reactive power compensator

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  12. Reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  13. Investigation of extra power loss sharing among photovoltaic inverters caused by reactive power management in distribution networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2014-01-01

    load and power loss on the feeders and individual inverters. Simplified energy loss evaluation is carried out here by using analytical average loss modeling of 2-level full bridge inverter coupled with network load flow analysis simulating one month period. The study shows that whatever Q control......Grid-connected photovoltaic (PV) inverters tailored with reactive power management feature can support the grid voltage especially when the voltage fluctuates near its admissible limits. Although Q control allows reducing the grid voltage elevation along the distribution feeder, it brings extra...... is selected, extra power loss is not a substantial amount to take into consideration. Similarly, loss difference among the inverters located at the various points is negligible....

  14. Coordinated Reactive Power and Voltage Management for Offshore Wind Farms with AC-connection

    DEFF Research Database (Denmark)

    Heussen, Kai

    2008-01-01

    This paper analyzes voltage and reactive power in a wind farm in dependence on switchable shunt and tap-changer settings in connection with the control ranges of flexible reactive power sources. Attention is paid to their interdependent effects on central control variables, such as voltage...... in the collection grid, reactive power exported to the grid and internal active power losses. An aggregated steady-state model of an offshore wind farm is presented and a reduced mathematical representation suitable for symbolic analysis is developed. A coordination scheme is proposed to coordinate fast continuous...... control inputs with slow tap-changing devices using a short-term prediction. The proposed scheme is aimed at balancing cost factors such as wear of switching components, active power loss within the wind farm and STATCOM capacity....

  15. Reactive power compensating system

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

    1987-01-01

    The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

  16. Reactive Power Compensating System.

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1985-01-04

    The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

  17. Voltage Control of Distribution Grids with Multi-Microgrids Using Reactive Power Management

    Directory of Open Access Journals (Sweden)

    WLODARCZYK, P.

    2015-02-01

    Full Text Available Low-voltage Microgrids can be valuable sources of ancillary services for the Distribution System Operators (DSOs. The aim of this paper was to study if and how multi-microgrids can contribute to Voltage Control (VC in medium-voltage distribution grids by means of reactive power generation and/or absorption. The hierarchical control strategy was proposed with the main focus on the tertiary control which was defined as optimal power flow problem. The interior-point algorithm was applied to optimise experimental benchmark grid with the presence of Distributed Energy Resources (DERs. Moreover, two primary objectives were formulated: active power losses and amount of reactive power used to reach the voltage profile. As a result the active power losses were minimised to the high extent achieving the savings around 22% during entire day.

  18. Reactivity and Power Distribution Management in LEU-loaded Linear B and BR

    International Nuclear Information System (INIS)

    Hartanto, Donny; Kim, Yonghee

    2013-01-01

    In this paper, the relatively high excess reactivity issue during the initial transitional period was addressed. The design target is to achieve a maximum excess reactivity of about 1.0 dollar to prevent the possibility of the prompt jump critical accident. The initial core is divided into 2 radial Zr-zones in order to reduce the excess reactivity. By doing this, the power profile at the BOC can also be flattened. After the optimum initial core configuration has been found, the blanket region is also divided into 2 radial Zr-zones in order to flatten the power distribution at EOC. The neutronic analyses were all performed using the Monte Carlo code McCARD with ENDF-B/VII.0 library. It was found that by using the concave Zr-zoning in the initial core of B and BR, the maximum excess reactivity can be effectively lowered. The radial power profile can also be successfully flattened by using the Zr-zoning and concave initial core. The concave concept deserves more investigations for better performances of the B and BR core

  19. Reactive Power from Distributed Energy

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-12-15

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  20. Reactive Power from Distributed Energy

    International Nuclear Information System (INIS)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-01-01

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  1. Literature Survey on Operational Voltage Control and Reactive Power Management on Transmission and Sub-Transmission Networks

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo, Marcelo A.; Samaan, Nader A.; Makarov, Yuri V.; Holzer, Jesse T.; Vallem, Mallikarjuna R.; Huang, Renke; Vyakaranam, Bharat GNVSR; Ke, Xinda; Pan, Feng

    2017-10-02

    Voltage and reactive power system control is generally performed following usual patterns of loads, based on off-line studies for daily and seasonal operations. This practice is currently challenged by the inclusion of distributed renewable generation, such as solar. There has been focus on resolving this problem at the distribution level; however, the transmission and sub-transmission levels have received less attention. This paper provides a literature review of proposed methods and solution approaches to coordinate and optimize voltage control and reactive power management, with an emphasis on applications at transmission and sub-transmission level. The conclusion drawn from the survey is that additional research is needed in the areas of optimizing switch shunt actions and coordinating all available resources to deal with uncertain patterns from increasing distributed renewable generation in the operational time frame. These topics are not deeply explored in the literature.

  2. A Tariff for Reactive Power

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would

  3. Design of reactive power procurement in deregulated electricity market

    African Journals Online (AJOL)

    Reactive power management is different in the deregulated electricity market of various countries. In this paper, a novel reactive power procurement model is proposed, which ensure secure and reliable operation of deregulated electricity market. Various issues of reactive power management in the deregulated electricity ...

  4. Substation Reactive Power Regulation Strategy

    Science.gov (United States)

    Zhang, Junfeng; Zhang, Chunwang; Ma, Daqing

    2018-01-01

    With the increasing requirements on the power supply quality and reliability of distribution network, voltage and reactive power regulation of substations has become one of the indispensable ways to ensure voltage quality and reactive power balance and to improve the economy and reliability of distribution network. Therefore, it is a general concern of the current power workers and operators that what kind of flexible and effective control method should be used to adjust the on-load tap-changer (OLTC) transformer and shunt compensation capacitor in a substation to achieve reactive power balance in situ, improve voltage pass rate, increase power factor and reduce active power loss. In this paper, based on the traditional nine-zone diagram and combining with the characteristics of substation, a fuzzy variable-center nine-zone diagram control method is proposed and used to make a comprehensive regulation of substation voltage and reactive power. Through the calculation and simulation of the example, this method is proved to have satisfactorily reconciled the contradiction between reactive power and voltage in real-time control and achieved the basic goal of real-time control of the substation, providing a reference value to the practical application of the substation real-time control method.

  5. Demand response strategy management with active and reactive power incentive in the smart grid: a two-level optimization approach

    Directory of Open Access Journals (Sweden)

    Ryuto Shigenobu

    2017-05-01

    Full Text Available High penetration of distributed generators (DGs using renewable energy sources (RESs is raising some important issues in the operation of modern po­wer system. The output power of RESs fluctuates very steeply, and that include uncertainty with weather conditions. This situation causes voltage deviation and reverse power flow. Several methods have been proposed for solving these problems. Fundamentally, these methods involve reactive power control for voltage deviation and/or the installation of large battery energy storage system (BESS at the interconnection point for reverse power flow. In order to reduce the installation cost of static var compensator (SVC, Distribution Company (DisCo gives reactive power incentive to the cooperating customers. On the other hand, photovoltaic (PV generator, energy storage and electric vehicle (EV are introduced in customer side with the aim of achieving zero net energy homes (ZEHs. This paper proposes not only reactive power control but also active power flow control using house BESS and EV. Moreover, incentive method is proposed to promote participation of customers in the control operation. Demand response (DR system is verified with several DR menu. To create profit for both side of DisCo and customer, two level optimization approach is executed in this research. Mathematical modeling of price elasticity and detailed simulations are executed by case study. The effectiveness of the proposed incentive menu is demonstrated by using heuristic optimization method.

  6. Reactive power supply by distributed generators

    OpenAIRE

    Braun, M.

    2008-01-01

    Distributed reactive power supply is necessary in distribution networks for an optimized network operation. This paper presents first the reactive power supply capabilities of generators connected to the distribution network (distributed generators). In a second step an approach is proposed of determining the energy losses resulting from reactive power supply by distributed generators. The costs for compensating these losses represent the operational costs of reactive power supply. These cost...

  7. Reactive power compensation a practical guide

    CERN Document Server

    Hofmann, Wolfgang; Just, Wolfgang

    2012-01-01

    The comprehensive resource on reactive power compensation, presenting the design, application and operation of reactive power equipment and installations The area of reactive power compensation is gaining increasing importance worldwide. If suitably designed, it is capable of improving voltage quality significantly, meaning that losses in equipment and power systems are reduced, the permissible loading of equipment can be increased, and the over-all stability of system operation improved. Ultimately, energy use and CO2 emisson are reduced. This unique guide discusses the

  8. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  9. Multiobjective clearing of reactive power market in deregulated power systems

    International Nuclear Information System (INIS)

    Rabiee, A.; Shayanfar, H.; Amjady, N.

    2009-01-01

    This paper presents a day-ahead reactive power market which is cleared in the form of multiobjective context. Total payment function (TPF) of generators, representing the payment paid to the generators for their reactive power compensation, is considered as the main objective function of reactive power market. Besides that, voltage security margin, overload index, and also voltage drop index are the other objective functions of the optimal power flow (OPF) problem to clear the reactive power market. A Multiobjective Mathematical Programming (MMP) formulation is implemented to solve the problem of reactive power market clearing using a fuzzy approach to choose the best compromise solution according to the specific preference among various non-dominated (pareto optimal) solutions. The effectiveness of the proposed method is examined based on the IEEE 24-bus reliability test system (IEEE 24-bus RTS). (author)

  10. The Large Customer Reactive Power Control Possibilities

    Directory of Open Access Journals (Sweden)

    Robert Małkowski

    2014-03-01

    Full Text Available In this paper the authors wish to draw attention to the rationale for, and the possibility of, the use of local reactive power sources by the Transmission Node Master Controller (TNMC. Large Customers (LC are one of the possible reactive power sources. The paper presents the issues related to the need for coordination between the control systems installed in the LC network, and coordination between control systems of the LC as well as master control systems in the network.

  11. Power manager and method for managing power

    NARCIS (Netherlands)

    Burchard, A.T.; Kersten, G.; Molnos, A.M.; Milutinovic, A.; Goossens, K.G.W.; Steffens, E.F.M.

    2009-01-01

    A power manager (106) and method for managing the power supplied to an electronic device is provided. Furthermore, a system wherein the power supplied to an electronic device is managed is provided. The power manager (106) is operative to monitor a hardware monitor (104) during a monitoring time

  12. Modelling of power-reactivity coefficient measurement

    International Nuclear Information System (INIS)

    Strmensky, C.; Petenyi, V.; Jagrik, J.; Minarcin, M.; Hascik, R.; Toth, L.

    2005-01-01

    Report describes results of modeling of power-reactivity coefficient analysis on power-level. In paper we calculate values of discrepancies arisen during transient process. These discrepancies can be arisen as result of experiment evaluation and can be caused by disregard of 3D effects on neutron distribution. The results are critically discussed (Authors)

  13. Joint excitation and reactive power control in thermal power plant

    Directory of Open Access Journals (Sweden)

    Dragosavac Jasna

    2013-01-01

    Full Text Available The coordinated voltage and reactive power controller, designed for the thermal power plant, is presented in the paper. A brief explanation of the need for such device is given and justification for commissioning of such equipment is outlined. After short description of the theoretical background of the proposed control design, the achieved features of the commissioned equipment are fully given. Achieved performances are illustrated by recorded reactive power and bus voltage responses after commissioning of the described equipment into the largest thermal power plant in Serbia. As it can be seen in presented records, all design targets are met.

  14. Multiagent voltage and reactive power control system

    Directory of Open Access Journals (Sweden)

    I. Arkhipov

    2014-12-01

    Full Text Available This paper is devoted to the research of multiagent voltage and reactive power control system development. The prototype of the system has been developed by R&D Center at FGC UES (Russia. The control system architecture is based on the innovative multiagent system theory application that leads to the achievement of several significant advantages (in comparison to traditional control systems implementation such as control system efficiency enhancement, control system survivability and cyber security.

  15. Application of the ant colony search algorithm to reactive power pricing in an open electricity market

    International Nuclear Information System (INIS)

    Ketabi, Abbas; Alibabaee, Ahmad; Feuillet, R.

    2010-01-01

    Reactive power management is essential to transfer real energy and support power system security. Developing an accurate and feasible method for reactive power pricing is important in the electricity market. In conventional optimal power flow models the production cost of reactive power was ignored. In this paper, the production cost of reactive power and investment cost of capacitor banks were included into the objective function of the OPF problem. Then, using ant colony search algorithm, the optimal problem was solved. Marginal price theory was used for calculation of the cost of active and reactive power at each bus in competitive electric markets. Application of the proposed method on IEEE 14-bus system confirms its validity and effectiveness. Results from several case studies show clearly the effects of various factors on reactive power price. (author)

  16. Blind spot in free power market debate. Reactive power problems are unavoidable

    International Nuclear Information System (INIS)

    Maessen, T.

    2002-01-01

    Import restrictions, switching problems, remotely readable meters appear to be temporary problems in a liberalised power market, according to statement of the Dutch the government. However, the issues surrounding reactive power management in the Dutch transmission and distribution networks are of a far more fundamental nature. The import of cheap foreign electricity could overload the domestic power grid sufficiently to compromise the security of supply [nl

  17. Pay-as-bid based reactive power market

    International Nuclear Information System (INIS)

    Amjady, N.; Rabiee, A.; Shayanfar, H.A.

    2010-01-01

    In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

  18. Pay-as-bid based reactive power market

    Energy Technology Data Exchange (ETDEWEB)

    Amjady, N. [Department of Electrical Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Rabiee, A., E-mail: Rabiee@iust.ac.i [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2010-02-15

    In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

  19. An introduction to reactive power compensation for wind farms

    International Nuclear Information System (INIS)

    Nigim, K.A.; Cairo Univ., Giza; Zobaa, A.F.; El Amin, I.

    2005-01-01

    The paper summarises the refereed contributions of seven articles reviewed for publication in the IJETP - Special Issue on 'Reactive compensation for wind farms'. The main goal of the special issue is to provide a forum to exchange information on the reactive power compensation requirements for wind farms and introducing possible price mechanisms for today's deregulated power industry. Uncompensated reactive power causes stress on the hosting utility grid as well as added expenses, which create in difficulties for power purchasing agreements from independent wind energy producers. Wind power producers need to comply with the hosting utility grid interconnection standards, e.g., voltage and frequency, as well as to provide controllable active and reactive sources of power. Active power supply is mainly dependent on the potential of wind power produced and the turbine design. Reactive power demand on the other hand depends on the conversion devices and the recovered power quantity fed to the grid. Static Var Compensators (SVC), Unified Power Quality Conditioners (UPQC), Unified Power Flow Controllers (UPFC), and the Distributed Static Synchronous Compensators (DSTATCOM) are all new emerging devices aimed at regulating the reactive power requirements. The excellent controllability of these devices has paved the way to flexible and dynamic controllers that are capable of regulating the flow of active and reactive power components. These devices are now suggested for the control of the reactive power requirement of wind generators. Studies have demonstrated acceptable voltage stabilisation results. This has increased the penetration level of wind power into existing distribution networks in many countries. (Author)

  20. Identification of fast power reactivity effect in nuclear power reactor

    International Nuclear Information System (INIS)

    Efanov, A.I.; Kaminskas, V.A.; Lavrukhin, V.S.; Rimidis, A.P.; Yanitskene, D.Yu.

    1987-01-01

    A nuclear power reactor is an object of control with distributed parameters, characteristics of which vary during operation time. At the same time the reactor as the object of control has internal feedback circuits, which are formed as a result of the effects of fuel parameters and a coolant (pressure, temperature, steam content) on the reactor breeding properties. The problem of internal feedback circuit identification in a nuclear power reactor is considered. Conditions for a point reactor identification are obtained and algorithms of parametric identification are constructed. Examples of identification of fast power reactivity effect for the RBMK-1000 reactor are given. Results of experimental testing have shown that the developed method of fast power reactivity effect identification permits according to the data of normal operation to construct adaptive models for the point nuclear reactor, designed for its behaviour prediction in stationary and transition operational conditions. Therefore, the models considered can be used for creating control systems of nuclear power reactor thermal capacity (of RBMK type reactor, in particular) which can be adapted to the change in the internal feedback circuit characteristics

  1. Design of reactive power procurement in deregulated electricity market

    African Journals Online (AJOL)

    user

    novel reactive power procurement model is proposed, which ensure secure and ..... The simulation is performed in the Matlab. .... focus of this paper is a reactive procurement market model, which is a basically two-step optimization process.

  2. Secure provision of reactive power ancillary services in competitive electricity markets

    Science.gov (United States)

    El-Samahy, Ismael

    The research work presented in this thesis discusses various complex issues associated with reactive power management and pricing in the context of new operating paradigms in deregulated power systems, proposing appropriate policy solutions. An integrated two-level framework for reactive power management is set forth, which is both suitable for a competitive market and ensures a secure and reliable operation of the associated power system. The framework is generic in nature and can be adopted for any electricity market structure. The proposed hierarchical reactive power market structure comprises two stages: procurement of reactive power resources on a seasonal basis, and real-time reactive power dispatch. The main objective of the proposed framework is to provide appropriate reactive power support from service providers at least cost, while ensuring a secure operation of the power system. The proposed procurement procedure is based on a two-step optimization model. First, the marginal benefits of reactive power supply from each provider, with respect to system security, are obtained by solving a loadability-maximization problem subject to transmission security constraints imposed by voltage and thermal limits. Second, the selected set of generators is determined by solving an optimal power flow (OPF)-based auction. This auction maximizes a societal advantage function comprising generators' offers and their corresponding marginal benefits with respect to system security, and considering all transmission system constraints. The proposed procedure yields the selected set of generators and zonal price components, which would form the basis for seasonal contracts between the system operator and the selected reactive power service providers. The main objective of the proposed reactive power dispatch model is to minimize the total payment burden on the Independent System Operator (ISO), which is associated with reactive power dispatch. The real power generation is

  3. An Enhanced Islanding Microgrid Reactive Power, Imbalance Power, and Harmonic Power Sharing Scheme

    DEFF Research Database (Denmark)

    He, Jinwei; Lin, Yun Wei; Blaabjerg, Frede

    2015-01-01

    To address inaccurate power sharing problems in autonomous islanding microgrids, an enhanced droop control method through online virtual impedance adjustment is proposed. First, a term associated with DG reactive power, imbalance power, or harmonic power is added to the conventional real power...

  4. An accurate autonomous islanding microgrid reactive power, imbalance power and harmonic power sharing scheme

    DEFF Research Database (Denmark)

    He, Jinwei; Li, Yun Wei; Blaabjerg, Frede

    2013-01-01

    To address inaccurate power sharing problems in autonomous islanding microgrids, an enhanced droop control method through adaptive virtual impedance adjustment is proposed. First, a term associated with DG reactive power, imbalance power or harmonic power is added to the conventional real power...

  5. 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.

  6. REACTIVE POWER DEVICES IN SYSTEMS OF ELECTRIC TRACTION

    Directory of Open Access Journals (Sweden)

    M. O. Kostin

    2010-04-01

    Full Text Available A comparative characteristic of different concepts and expressions for determination of reactive power in the circuits with non-sinusoidal electric values has been given. For the first Ukrainian electric locomotives of DE1 type with the system of DC electric traction, the values of reactive power after Budeany, Fryze, and also the differential, integral and generalized reactive powers have been determined. Some measures on reducing its consumption by the DC electric rolling stock have been suggested.

  7. Land Warrior Power Management

    National Research Council Canada - National Science Library

    Sanders, David

    2003-01-01

    .... The improvement is incremental; yet the goal of power management for this system is to significantly increase the length of time a single source can supply the system with power without resupply...

  8. Power flattening and reactivity suppression strategies for the Canadian supercritical water reactor concept

    International Nuclear Information System (INIS)

    McDonald, M.; Colton, A.; Pencer, J.

    2015-01-01

    The Canadian supercritical water-cooled reactor (SCWR) is a conceptual heavy water moderated, supercritical light water cooled pressure tube reactor. In contrast to current heavy water power reactors, the Canadian SCWR will be a batch fuelled reactor. Associated with batch fuelling is a large beginning-of-cycle excess reactivity. Furthermore, radial power peaking arising as a consequence of batch refuelling must be mitigated in some way. In this paper, burnable neutron absorber (BNA) added to fuel and absorbing rods inserted into the core are considered for reactivity management and power flattening. A combination of approaches appears adequate to reduce the core radial power peaking, while also providing reactivity suppression. (author)

  9. An introduction to reactive power compensation for wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Nigim, K.A. [Waterloo Univ., Ont. (Canada). Dept. of Electrical and Computer Engineering; Cairo Univ., Giza (Egypt). Faculty of Engineering; Zobaa, A.F.; El Amin, I. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering

    2005-07-01

    The paper summarises the refereed contributions of seven articles reviewed for publication in the IJETP - Special Issue on 'Reactive compensation for wind farms'. The main goal of the special issue is to provide a forum to exchange information on the reactive power compensation requirements for wind farms and introducing possible price mechanisms for today's deregulated power industry. Uncompensated reactive power causes stress on the hosting utility grid as well as added expenses, which create in difficulties for power purchasing agreements from independent wind energy producers. Wind power producers need to comply with the hosting utility grid interconnection standards, e.g., voltage and frequency, as well as to provide controllable active and reactive sources of power. Active power supply is mainly dependent on the potential of wind power produced and the turbine design. Reactive power demand on the other hand depends on the conversion devices and the recovered power quantity fed to the grid. Static Var Compensators (SVC), Unified Power Quality Conditioners (UPQC), Unified Power Flow Controllers (UPFC), and the Distributed Static Synchronous Compensators (DSTATCOM) are all new emerging devices aimed at regulating the reactive power requirements. The excellent controllability of these devices has paved the way to flexible and dynamic controllers that are capable of regulating the flow of active and reactive power components. These devices are now suggested for the control of the reactive power requirement of wind generators. Studies have demonstrated acceptable voltage stabilisation results. This has increased the penetration level of wind power into existing distribution networks in many countries. (Author)

  10. Dynamic Reactive Power Control in Offshore HVDC Connected Wind Power Plants

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Cutululis, Nicolaos Antonio; Rather, Zakir Hussain

    2016-01-01

    This paper presents a coordinated reactive power control for a HVDC connected cluster of offshore wind power plants (WPPs). The reactive power reference for the WPP cluster is estimated by an optimization algorithm aiming at minimum active power losses in the offshore AC Grid. For each optimal......, such as wind turbine (WT) terminal, collector cable, and export cable, on the dynamic voltage profile of the offshore grid is investigated. Furthermore, the dynamic reactive power contribution from WTs from different WPPs of the cluster for such faults has also been studied....... reactive power set point, the OWPP cluster controller generates reactive power references for each WPP which further sends the AC voltage/ reactive power references to the associated WTs based on their available reactive power margin. The impact of faults at different locations in the offshore grid...

  11. Reactive power control with CHP plants - A demonstration

    DEFF Research Database (Denmark)

    Nyeng, Preben; Østergaard, Jacob; Andersen, Claus A.

    2010-01-01

    power rating of 7.3 MW on two synchronous generators. A closed-loop control is implemented, that remote controls the CHP plant to achieve a certain reactive power flow in a near-by substation. The solution communicates with the grid operator’s existing SCADA system to obtain measurements from...... lines to underground cables has changed the reactive power balance, and third, the TSO has introduced restrictions in the allowed exchange of reactive power between the transmission system and distribution grids (known as the Mvar-arrangement). The demonstration includes a CHP plant with an electric......In this project the potential for ancillary services provision by distributed energy resources is investigated. Specifically, the provision of reactive power control by combined heat and power plants is examined, and the application of the new standard for DER communication systems, IEC 61850...

  12. Portable digital reactivity meter for power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, G [Nuklear-Ingenieur Service G.m.b.H., Hanau (Germany, F.R.)

    1977-07-01

    A digital reactivity meter has been developed, which can be used for all kinds of kinetic reactivity measurements in PWR's and BWR's. The input signals may be supplied by standard neutron detectors of the reactor. The hardware configuration consists of a minicomputer with ADC and DAC, a 'Silent' terminal and a high speed paper tape reader/punch. It is easily transportable. The reactivity meter solves the inverse kinetics equations for 6 delayed neutron groups, simultaneously for up to 8 logarithmic or linear neutron flux signals. It has been successfully tested at Biblis A PWR and the KRB BWR.

  13. Formation for the calculation of reactivity without nuclear power history

    International Nuclear Information System (INIS)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino; Carvalho Da Silva, Fernando

    2007-01-01

    This paper presents a new method for the solution of the inverse point kinetics equation. This method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. With the imposition of conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has very special characteristics, amongst which the possibility of using longer sampling period, and the possibility of restarting the calculation, after its interruption, allowing the calculation of reactivity in a non-continuous way. Beside that, the reactivity can be obtained independent of the nuclear power memory. (author)

  14. Reactive power control methods for improved reliability of wind power inverters under wind speed variations

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2012-01-01

    method to relieve the thermal cycling of power switching devices under severe wind speed variations, by circulating reactive power among the parallel power converters in a WTS or among the WTS's in a wind park. The amount of reactive power is adjusted to limit the junction temperature fluctuation...

  15. Reactive power compensation and loss reduction in large industrial enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, S; Gajic, B; Mijailovic, S [Institute Nikola Tesla, Beograd (Yugoslavia)

    1991-12-01

    This paper considers the reactive power compensation and the active power and energy loss reduction of large radial power networks in the Serbian mine and smelting industry. It gives an efficient optimization procedure for positioning and sizing capacitors in large industrial systems integrated with a simple network analysis method. (Author).

  16. Managing Functional Power

    DEFF Research Database (Denmark)

    Rosenstand, Claus Andreas Foss; Laursen, Per Kyed

    2013-01-01

    How does one manage functional power relations between leading functions in vision driven digital media creation, and this from idea to master during the creation cycle? Functional power is informal, and it is understood as roles, e.g. project manager, that provide opportunities to contribute...... to the product quality. The area of interest is the vision driven digital media industry in general; however, the point of departure is the game industry due to its aesthetic complexity. The article's contribution to the area is a power graph, which shows the functional power of the leading functions according...... to a general digital media creation cycle. This is used to point out potential power conflicts and their consequences. It is concluded that there is normally more conflict potential in vision driven digital media creation than in digital media creation in general or in software development. The method...

  17. Broadband and High power Reactive Jamming Resilient Wireless Communication

    Science.gov (United States)

    2017-10-21

    Broadband and High -power Reactive Jamming Resilient Wireless Communication The views, opinions and/or findings contained in this report are those of... available in extremely hostile environments, where FHSS and DSSS are completely defeated by a broadband and high -power reactive jammer. b. Wireless...SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS

  18. EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6

  19. A New Framework for Reactive Power Market Considering Power System Security

    Directory of Open Access Journals (Sweden)

    A. Rabiee

    2009-09-01

    Full Text Available This paper presents a new framework for the day-ahead reactive power market based on the uniform auction price. Voltage stability and security have been considered in the proposed framework. Total Payment Function (TPF is suggested as the objective function of the Optimal Power Flow (OPF used to clear the reactive power market. Overload, voltage drop and voltage stability margin (VSM are included in the constraints of the OPF. Another advantage of the proposed method is the exclusion of Lost Opportunity Cost (LOC concerns from the reactive power market. The effectiveness of the proposed reactive power market is studied based on the CIGRÉ-32 bus test system.

  20. A DFIG Islanding Detection Scheme Based on Reactive Power Infusion

    Science.gov (United States)

    Wang, M.; Liu, C.; He, G. Q.; Li, G. H.; Feng, K. H.; Sun, W. W.

    2017-07-01

    A lot of research has been done on photovoltaic (the “PV”) power system islanding detection in recent years. As a comparison, much less attention has been paid to islanding in wind turbines. Meanwhile, wind turbines can work in islanding conditions for quite a long period, which can be harmful to equipments and cause safety hazards. This paper presents and examines a double fed introduction generation (the “DFIG”) islanding detection scheme based on feedback of reactive power and frequency and uses a trigger signal of reactive power infusion which can be obtained by dividing the voltage total harmonic distortion (the "THD") by the voltage THD of last cycle to avoid the deterioration of power quality. This DFIG islanding detection scheme uses feedback of reactive power current loop to amplify the frequency differences in islanding and normal conditions. Simulation results show that the DFIG islanding detection scheme is effective.

  1. 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...

  2. Compensation of Reactive Power from Wind Turbines with Power Electronics Equipment

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Kaas

    1996-01-01

    Wind turbines with induction generators consume reactive power. Apart from the no load consumption, which is nearing constant and is being compensated for using capacitors, the consumption of reactive power varies almost proportional with the power production, which can vary immensely. Except tha...

  3. Coordination of baseload power plant group control with static reactive power compensator control

    Directory of Open Access Journals (Sweden)

    Zbigniew Szczerba

    2012-06-01

    Full Text Available Reactive power sources in power system nodes: generators and static reactive power compensators, are controlled by control systems. Generators – by generator node group controllers, compensators – by voltage controllers. The paper presents issues of these control systems’ coordination and proposals for its implementation.

  4. Voltage Sag Mitigation and Load Reactive Power Compensation by UPQC

    OpenAIRE

    Ajitha, P; Jananisri, D

    2014-01-01

    This paper presents Unified Power Quality Conditioner(UPQC) that consist of series inverter and shunt inverter in back to back configuration which simultaneously compensate the power quality(PQ) problems of both voltage sag and load reactive power compensation . In this paper ,Neural network is tool which is considered for solving power quality problems. The simulation results from MATLAB/SIMULINK are discussed to validate the proposed method.

  5. 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.

  6. A new computational method for reactive power market clearing

    International Nuclear Information System (INIS)

    Zhang, T.; Elkasrawy, A.; Venkatesh, B.

    2009-01-01

    After deregulation of electricity markets, ancillary services such as reactive power supply are priced separately. However, unlike real power supply, procedures for costing and pricing reactive power supply are still evolving and spot markets for reactive power do not exist as of now. Further, traditional formulations proposed for clearing reactive power markets use a non-linear mixed integer programming formulation that are difficult to solve. This paper proposes a new reactive power supply market clearing scheme. Novelty of this formulation lies in the pricing scheme that rewards transformers for tap shifting while participating in this market. The proposed model is a non-linear mixed integer challenge. A significant portion of the manuscript is devoted towards the development of a new successive mixed integer linear programming (MILP) technique to solve this formulation. The successive MILP method is computationally robust and fast. The IEEE 6-bus and 300-bus systems are used to test the proposed method. These tests serve to demonstrate computational speed and rigor of the proposed method. (author)

  7. Improvement of linear reactivity methods and application to long range fuel management

    International Nuclear Information System (INIS)

    Woehlke, R.A.; Quan, B.L.

    1982-01-01

    The original development of the linear reactivity theory assumes flat burnup, batch by batch. The validity of this assumption is explored using multicycle burnup data generated with a detailed 3-D SIMULATE model. The results show that the linear reactivity method can be improved by correcting for batchwise power sharing. The application of linear reactivity to long range fuel management is demonstrated in several examples. Correcting for batchwise power sharing improves the accuracy of the analysis. However, with regard to the sensitivity of fuel cost to changes in various parameters, the corrected and uncorrected linear reactivity theories give remarkably similar results

  8. Reactive power planning with FACTS devices using gravitational search algorithm

    Directory of Open Access Journals (Sweden)

    Biplab Bhattacharyya

    2015-09-01

    Full Text Available In this paper, Gravitational Search Algorithm (GSA is used as optimization method in reactive power planning using FACTS (Flexible AC transmission system devices. The planning problem is formulated as a single objective optimization problem where the real power loss and bus voltage deviations are minimized under different loading conditions. GSA based optimization algorithm and particle swarm optimization techniques (PSO are applied on IEEE 30 bus system. Results show that GSA can also be a very effective tool for reactive power planning.

  9. Ant colony search algorithm for optimal reactive power optimization

    Directory of Open Access Journals (Sweden)

    Lenin K.

    2006-01-01

    Full Text Available The paper presents an (ACSA Ant colony search Algorithm for Optimal Reactive Power Optimization and voltage control of power systems. ACSA is a new co-operative agents’ approach, which is inspired by the observation of the behavior of real ant colonies on the topic of ant trial formation and foraging methods. Hence, in the ACSA a set of co-operative agents called "Ants" co-operates to find good solution for Reactive Power Optimization problem. The ACSA is applied for optimal reactive power optimization is evaluated on standard IEEE, 30, 57, 191 (practical test bus system. The proposed approach is tested and compared to genetic algorithm (GA, Adaptive Genetic Algorithm (AGA.

  10. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  11. Calculation of research reactor RA power at uncontrolled reactivity changes

    International Nuclear Information System (INIS)

    Cupac, S.

    1978-01-01

    The safety analysis of research reactor RA involves also the calculation of reactor power at uncontrolled reactivity changes. The corresponding computer code, based on Point Kinetics Model has been made. The short review of method applied for solving kinetic equations is given and several examples illustrating the reactor behaviour at various reactivity changes are presented. The results already obtained are giving rather rough picture of reactor behaviour in considered situations. This is the consequence of using simplified feed back and reactor cooling models, as well as temperature reactivity coefficients, which do not correspond to the actual reactor RA structure (which is now only partly fulfilled with 80% enriched uranium fuel). (author) [sr

  12. A stochastic framework for clearing of reactive power market

    International Nuclear Information System (INIS)

    Amjady, N.; Rabiee, A.; Shayanfar, H.A.

    2010-01-01

    This paper presents a new stochastic framework for clearing of day-ahead reactive power market. The uncertainty of generating units in the form of system contingencies are considered in the reactive power market-clearing procedure by the stochastic model in two steps. The Monte-Carlo Simulation (MCS) is first used to generate random scenarios. Then, in the second step, the stochastic market-clearing procedure is implemented as a series of deterministic optimization problems (scenarios) including non-contingent scenario and different post-contingency states. In each of these deterministic optimization problems, the objective function is total payment function (TPF) of generators which refers to the payment paid to the generators for their reactive power compensation. The effectiveness of the proposed model is examined based on the IEEE 24-bus Reliability Test System (IEEE 24-bus RTS). (author)

  13. Characteristics of a reactor with power reactivity feedback

    International Nuclear Information System (INIS)

    Li Fengyu; Zhang Yusheng; Zhang Guangfu; Liu Ying

    2008-01-01

    The point-reactor model with power reactivity feedback becomes a nonlinear system. Its dynamic characteristic shows great complexity. According to the mathematic definition of stability in differential equation qualitative theory, the model of a reactor with power reactivity feedback is judged unstable. The equilibrium point is a saddle-node point. A portion of the trajectory in the neighborhood of the equilibrium point is parabolic fan curve, and the other is hyperbolic fan curve. Based on phase locus near the equilibrium point, it is pointed out that the model is still stable within physical limits. The difference between stabilities in the mathematical sense and in the physical sense is indicated. (authors)

  14. Reactive adsorption: A cleaner technology in nuclear power plants

    International Nuclear Information System (INIS)

    Marton, G.; Szanya, T.; Hanak, L.

    1996-01-01

    Cleaner technology prefers work with minimal loss and the wastes cause the less environmental damages. In the spirit of the previous sentence in the present paper reactive adsorption is investigated for the removal of radioactive nuclides from nuclear power plant decontamination solutions. During alkaline, oxidative decontamination of nuclear power plant equipment a radioactive solution is produced. Owing to the storing difficulties of radioactive solutions it is necessary to develop a method for the in situ treatment of radioactive, alkaline, oxidative decontamination solutions, and for the concentration of radioactive components. Reactive adsorption seems to be promising for this purpose. 3 refs., 8 figs., 1 tab

  15. Reactive Power Pricing Model Considering the Randomness of Wind Power Output

    Science.gov (United States)

    Dai, Zhong; Wu, Zhou

    2018-01-01

    With the increase of wind power capacity integrated into grid, the influence of the randomness of wind power output on the reactive power distribution of grid is gradually highlighted. Meanwhile, the power market reform puts forward higher requirements for reasonable pricing of reactive power service. Based on it, the article combined the optimal power flow model considering wind power randomness with integrated cost allocation method to price reactive power. Meanwhile, considering the advantages and disadvantages of the present cost allocation method and marginal cost pricing, an integrated cost allocation method based on optimal power flow tracing is proposed. The model realized the optimal power flow distribution of reactive power with the minimal integrated cost and wind power integration, under the premise of guaranteeing the balance of reactive power pricing. Finally, through the analysis of multi-scenario calculation examples and the stochastic simulation of wind power outputs, the article compared the results of the model pricing and the marginal cost pricing, which proved that the model is accurate and effective.

  16. Management of hepatitis B reactivation in patients receiving cancer chemotherapy

    OpenAIRE

    Huang, Yi-Wen; Chung, Raymond T.

    2012-01-01

    Hepatitis B virus (HBV) reactivation is well documented in previously resolved or inactive HBV carriers who receive cancer chemotherapy. The consequences of HBV reactivation range from self-limited conditions to fulminant hepatic failure and death. HBV reactivation also leads to premature termination of chemotherapy or delay in treatment schedules. This review summarizes current knowledge of management of HBV reactivation in patients receiving cancer chemotherapy. HBV surface antigen (HBsAg) ...

  17. Reactivity calculation with reduction of the nuclear power fluctuations

    International Nuclear Information System (INIS)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino

    2009-01-01

    A new formulation is presented in this paper for the calculation of reactivity, which is simpler than the formulation that uses the Laplace and Z transforms. A treatment is also made to reduce the intensity of the noise found in the nuclear power signal used in the calculation of reactivity. Two classes of different filters are used for that. This treatment is based on the fact that the reactivity can be written by using the compose Simpson's rule resulting in a sum of two convolution terms with response to the impulse that is characteristic of a linear system. The linear part is calculated by using the filter named finite impulse response filter (FIR). The non-linear part is calculated using the filter exponentially adjusted by the least squares method, which does not cause attenuation in the reactivity calculation.

  18. Reactivity calculation with reduction of the nuclear power fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Suescun Diaz, Daniel [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914 RJ (Brazil)], E-mail: dsuescun@hotmail.com; Senra Martinez, Aquilino [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914 RJ (Brazil)

    2009-05-15

    A new formulation is presented in this paper for the calculation of reactivity, which is simpler than the formulation that uses the Laplace and Z transforms. A treatment is also made to reduce the intensity of the noise found in the nuclear power signal used in the calculation of reactivity. Two classes of different filters are used for that. This treatment is based on the fact that the reactivity can be written by using the compose Simpson's rule resulting in a sum of two convolution terms with response to the impulse that is characteristic of a linear system. The linear part is calculated by using the filter named finite impulse response filter (FIR). The non-linear part is calculated using the filter exponentially adjusted by the least squares method, which does not cause attenuation in the reactivity calculation.

  19. Dynamic Reactive Power Compensation of Large Scale Wind Integrated Power System

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2015-01-01

    wind turbines especially wind farms with additional grid support functionalities like dynamic support (e,g dynamic reactive power support etc.) and ii) refurbishment of existing conventional central power plants to synchronous condensers could be one of the efficient, reliable and cost effective option......Due to progressive displacement of conventional power plants by wind turbines, dynamic security of large scale wind integrated power systems gets significantly compromised. In this paper we first highlight the importance of dynamic reactive power support/voltage security in large scale wind...... integrated power systems with least presence of conventional power plants. Then we propose a mixed integer dynamic optimization based method for optimal dynamic reactive power allocation in large scale wind integrated power systems. One of the important aspects of the proposed methodology is that unlike...

  20. Reactive Power Impact on Lifetime Prediction of Two-level Wind Power Converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, M.

    2013-01-01

    The influence of reactive power injection on the dominating two-level wind power converter is investigated and compared in terms of power loss and thermal behavior. Then the lifetime of both the partial-scale and full-scale power converter is estimated based on the widely used Coffin-Manson model...

  1. Coupled energy and reactive power market clearing considering power system security

    International Nuclear Information System (INIS)

    Rabiee, Abdorreza; Shayanfar, Heidarali; Amjady, Nima

    2009-01-01

    In a deregulated environment, when talking about electricity markets, one usually refers to energy market, paying less attention to the reactive power market. Active and reactive powers are, however, coupled through the AC power flow equations and branch loading limits as well as the synchronous generators capability curves. However, the sequential approach for energy and reactive power markets cannot present the optimal solution due to the interactions between these markets. For instance, clearing of the reactive power market can change active power dispatch (e.g. due to a change of transmission system losses and the capability curve limitation), which can lead to degradation of the energy market clearing point. This paper presents a coupled day ahead energy and reactive power market based on the pay-at-MCP settlement mechanism. Besides, the proposed coupled framework considers voltage stability and security issues and branch loading limits. The coupled market is cleared through optimal power flow (OPF). Its objective function includes total payment of generating units for their active power production along with the total payment function (TPF) of units for their reactive power compensation. Moreover, lost opportunity cost (LOC) of the units is also considered. The effectiveness of the proposed framework is examined on the IEEE 24 bus Reliability Test System

  2. Coupled energy and reactive power market clearing considering power system security

    Energy Technology Data Exchange (ETDEWEB)

    Rabiee, Abdorreza; Shayanfar, Heidarali [Center of Excellence for Power System Automation and Operation, Electrical Engineering Department, Iran University of Science and Technology (IUST), Tehran (Iran); Amjady, Nima [Department of Electrical Engineering, Semnan University, Semnan (Iran)

    2009-04-15

    In a deregulated environment, when talking about electricity markets, one usually refers to energy market, paying less attention to the reactive power market. Active and reactive powers are, however, coupled through the AC power flow equations and branch loading limits as well as the synchronous generators capability curves. However, the sequential approach for energy and reactive power markets cannot present the optimal solution due to the interactions between these markets. For instance, clearing of the reactive power market can change active power dispatch (e.g. due to a change of transmission system losses and the capability curve limitation), which can lead to degradation of the energy market clearing point. This paper presents a coupled day ahead energy and reactive power market based on the pay-at-MCP settlement mechanism. Besides, the proposed coupled framework considers voltage stability and security issues and branch loading limits. The coupled market is cleared through optimal power flow (OPF). Its objective function includes total payment of generating units for their active power production along with the total payment function (TPF) of units for their reactive power compensation. Moreover, lost opportunity cost (LOC) of the units is also considered. The effectiveness of the proposed framework is examined on the IEEE 24 bus Reliability Test System. (author)

  3. Dynamic Performance of the ITER Reactive Power Compensation System

    International Nuclear Information System (INIS)

    Sheng Zhicai; Fu Peng; Xu Liuwei

    2011-01-01

    Dynamic performance of a reactive power compensation (RPC) system for the international thermonuclear experimental reactor (ITER) power supply is presented. Static var compensators (SVCs) are adopted to mitigate voltage fluctuation and reduce the reactive power down to a level acceptable for the French/European 400 kV grid. A voltage feedback and load power feedforward controller for SVC is proposed, with the feedforward loop intended to guarantee short response time and the feedback loop ensuring good dynamics and steady characteristics of SVC. A mean filter was chosen to measure the control signals to improve the dynamic response. The dynamic performance of the SVC is verified by simulations using PSCAD/EMTDC codes.

  4. Index-based reactive power compensation scheme for voltage regulation

    Science.gov (United States)

    Dike, Damian Obioma

    2008-10-01

    Increasing demand for electrical power arising from deregulation and the restrictions posed to the construction of new transmission lines by environment, socioeconomic, and political issues had led to higher grid loading. Consequently, voltage instability has become a major concern, and reactive power support is vital to enhance transmission grid performance. Improved reactive power support to distressed grid is possible through the application of relatively unfamiliar emerging technologies of "Flexible AC Transmission Systems (FACTS)" devices and "Distributed Energy Resources (DERS)." In addition to these infrastructure issues, a lack of situational awareness by system operators can cause major power outages as evidenced by the August 14, 2003 widespread North American blackout. This and many other recent major outages have highlighted the inadequacies of existing power system indexes. In this work, a novel "Index-based reactive compensation scheme" appropriate for both on-line and off-line computation of grid status has been developed. A new voltage stability index (Ls-index) suitable for long transmission lines was developed, simulated, and compared to the existing two-machine modeled L-index. This showed the effect of long distance power wheeling amongst regional transmission organizations. The dissertation further provided models for index modulated voltage source converters (VSC) and index-based load flow analysis of both FACTS and microgrid interconnected power systems using the Newton-Raphson's load flow model incorporated with multi-FACTS devices. The developed package has been made user-friendly through the embodiment of interactive graphical user interface and implemented on the IEEE 14, 30, and 300 bus systems. The results showed reactive compensation has system wide-effect, provided readily accessible system status indicators, ensured seamless DERs interconnection through new islanding modes and enhanced VSC utilization. These outcomes may contribute

  5. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Guerrero, Josep M.

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...

  6. Power and reactive power simultaneous control by 0.5 MJ superconducting magnet energy storage

    International Nuclear Information System (INIS)

    Ise, Toshifumi; Tsuji, Kiichiro; Murakami, Yoshishige

    1984-01-01

    Superconducting magnet energy storage (SMES) is expected to be widely applied to the pulsed sources for fusion reactor research and to the energy storage substituting for pumping-up power stations, because of its fast energy storing and discharging and very high efficiency. Some results have been obtained so far. In this paper, however, the simultaneous control of power and reactive power is considered for an energy storage composed of two sets of thyristorized power conversion system and superconducting magnets in series connection, and a direct digital control system is described on the principle, design and configuration including the compensator, and on the experiment using the 0.5 MJ superconducting magnet energy storage installed in the Superconduction Engineering Experiment Center, Osaka University. The results obtained are as follows: (1) P control priority mode and Q control priority mode (in which power and reactive power control has priority, respectively) were proposed as the countermeasures when the simultaneous control of power and reactive power became impossible; (2) the design method was established, by which power and reactive power control loops can independently be designed as a result of simulation; (3) the achievement of the simultaneous control of power and reactive power was confirmed by using P-control priority mode and Q-control priority mode, in the experiment using the control system designed by simulation. The validity of simulation model was also confirmed by actual response waveforms. (Wakatsuki, Y.)

  7. Combination of AC Transmission Expansion Planning and Reactive Power Planning in the restructured power system

    International Nuclear Information System (INIS)

    Hooshmand, Rahmat-Allah; Hemmati, Reza; Parastegari, Moein

    2012-01-01

    Highlights: ► To overcome the disadvantages of DC model in Transmission Expansion Planning, AC model should be used. ► The Transmission Expansion Planning associated with Reactive Power Planning results in fewer new transmission lines. ► Electricity market concepts should be considered in Transmission Expansion Planning problem. ► Reliability aspects should be considered in Transmission Expansion Planning problem. ► Particle Swarm Optimization is a suitable optimization method to solve Transmission Expansion Planning problem. - Abstract: Transmission Expansion Planning (TEP) is an important issue in power system studies. It involves decisions on location and number of new transmission lines. Before deregulation of the power system, the goal of TEP problem was investment cost minimization. But in the restructured power system, nodal prices, congestion management, congestion surplus and so on, have been considered too. In this paper, an AC model of TEP problem (AC-TEP) associated with Reactive Power Planning (RPP) is presented. The goals of the proposed planning problem are to minimize investment cost and maximize social benefit at the same time. In the proposed planning problem, in order to improve the reliability of the system the Expected Energy Not Supplied (EENS) index of the system is limited by a constraint. For this purpose, Monte Carlo simulation method is used to determine the EENS. Particle Swarm Optimization (PSO) method is used to solve the proposed planning problem which is a nonlinear mixed integer optimization problem. Simulation results on Garver and RTS systems verify the effectiveness of the proposed planning problem for reduction of the total investment cost, EENS index and also increasing social welfare of the system.

  8. Managing power risk

    International Nuclear Information System (INIS)

    Rudd, D.C.

    1999-01-01

    Issues regarding the management of financial risks in the electric power market were discussed. The nature of the risk was defined for electricity producers, local utilities, traders/dealers, and brokers, each of which are exposed to different types of risks with the exception of credit risk, which is common to all. The main features of options, swaps, CFDs, bilateral financial contracts, futures contracts and the terms of the NYMEX electricity contract were outlined. Basic derivative strategies, the role of the broker, the elements of emissions trading, and trading strategies for consumers were also explained. 3 fig

  9. Modelling and automatic reactive power control of isolated wind-diesel hybrid power systems using ANN

    International Nuclear Information System (INIS)

    Bansal, R.C.

    2008-01-01

    This paper presents an artificial neural network (ANN) based approach to tune the parameters of the static var compensator (SVC) reactive power controller over a wide range of typical load model parameters. The gains of PI (proportional integral) based SVC are optimised for typical values of the load voltage characteristics (n q ) by conventional techniques. Using the generated data, the method of multi-layer feed forward ANN with error back propagation training is employed to tune the parameters of the SVC. An ANN tuned SVC controller has been applied to control the reactive power of a variable slip/speed isolated wind-diesel hybrid power system. It is observed that the maximum deviations of all parameters are more for larger values of n q . It has been shown that initially synchronous generator supplies the reactive power required by the induction generator and/or load, and the latter reactive power is purely supplied by the SVC

  10. Modelling and automatic reactive power control of isolated wind-diesel hybrid power systems using ANN

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, R.C. [Electrical and Electronics Engineering Division, School of Engineering and Physics, The University of the South Pacific, Suva (Fiji)

    2008-02-15

    This paper presents an artificial neural network (ANN) based approach to tune the parameters of the static var compensator (SVC) reactive power controller over a wide range of typical load model parameters. The gains of PI (proportional integral) based SVC are optimised for typical values of the load voltage characteristics (n{sub q}) by conventional techniques. Using the generated data, the method of multi-layer feed forward ANN with error back propagation training is employed to tune the parameters of the SVC. An ANN tuned SVC controller has been applied to control the reactive power of a variable slip/speed isolated wind-diesel hybrid power system. It is observed that the maximum deviations of all parameters are more for larger values of n{sub q}. It has been shown that initially synchronous generator supplies the reactive power required by the induction generator and/or load, and the latter reactive power is purely supplied by the SVC. (author)

  11. SSP Power Management and Distribution

    Science.gov (United States)

    Lynch, Thomas H.; Roth, A. (Technical Monitor)

    2000-01-01

    Space Solar Power is a NASA program sponsored by Marshall Space Flight Center. The Paper presented here represents the architectural study of a large power management and distribution (PMAD) system. The PMAD supplies power to a microwave array for power beaming to an earth rectenna (Rectifier Antenna). The power is in the GW level.

  12. 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.

  13. Optimum Arrangement of Reactive Power Sources While Using Genetic Algori

    Directory of Open Access Journals (Sweden)

    A. M. Gashimov

    2010-01-01

    Full Text Available Reduction of total losses in distribution electricity supply network is considered as an important measure which serves for improvement of efficiency of electric power supply systems. This objective can be achieved by optimum distribution of reactive power sources in proper places of distribution electricity supply network. The proposed methodology is based on application of a genetic algorithm. Total expenses for installation of capacitor banks, their operation and also expenses related to electric power losses are considered as an efficiency function which is used for determination of places with optimum values of capacitor bank power. The methodology is the most efficient for selection of optimum places in the network where it is necessary to install capacitor banks with due account of their power control depending on a switched-on load value in the units.

  14. Device for measuring active, reactive and apparent power

    Energy Technology Data Exchange (ETDEWEB)

    Bartosinski, E.; Wieland, J.

    1982-09-30

    The plan consists of a traditional electrodynamic mechanism for measuring power (IM) supplemented by three switches, two rectifiers, resistor, included in parallel, and phaseshifting throttle included in series with the voltage coil of the IM. This makes it possible by selection to perform three types of measurements: active power of alternating current or power of direct current, only the voltage coils and the IM current are engaged; reactive power, the resistor and the throttle are additionally engaged by the aforementioned method; complete (apparent) power--the current and the voltage are supplied directly to the IM coils, but in contrast to the first case, through rectifiers. The influence of the highest harmonic components of voltage and current which are not significant for industrial measurements can be eliminated in necessary cases using filtering devices.

  15. Stochastic reactive power dispatch in hybrid power system with intermittent wind power generation

    International Nuclear Information System (INIS)

    Taghavi, Reza; Seifi, Ali Reza; Samet, Haidar

    2015-01-01

    Environmental concerns besides fuel costs are the predominant reasons for unprecedented escalating integration of wind turbine on power systems. Operation and planning of power systems are affected by this type of energy due to the intermittent nature of wind speed inputs with high uncertainty in the optimization output variables. Consequently, in order to model this high inherent uncertainty, a PRPO (probabilistic reactive power optimization) framework should be devised. Although MC (Monte-Carlo) techniques can solve the PRPO with high precision, PEMs (point estimate methods) can preserve the accuracy to attain reasonable results when diminishing the computational effort. Also, this paper introduces a methodology for optimally dispatching the reactive power in the transmission system, while minimizing the active power losses. The optimization problem is formulated as a LFP (linear fuzzy programing). The core of the problem lay on generation of 2m + 1 point estimates for solving PRPO, where n is the number of input stochastic variables. The proposed methodology is investigated using the IEEE-14 bus test system equipped with HVDC (high voltage direct current), UPFC (unified power flow controller) and DFIG (doubly fed induction generator) devices. The accuracy of the method is demonstrated in the case study. - Highlights: • This paper uses stochastic loads in optimization process. • AC–DC load flow is modified to use some advantages of DC part in optimization process. • UPFC and DFIG are simulated in a way that could be effective in optimization process. • Fuzzy set has been used as an uncertainty analysis tool in the optimization

  16. Adaptive Reactive Power Control of PV Power Plants for Improved Power Transfer Capability under Ultra-Weak Grid Conditions

    DEFF Research Database (Denmark)

    Yang, Dongsheng; Wang, Xiongfei; Liu, Fangcheng

    2018-01-01

    with the unity power factor. Then, considering the reactive power compensation from PV inverters, the minimum SCR in respect to Power Factor (PF) is derived, and the optimized coordination of the active and reactive power is exploited. It is revealed that the power transfer capability of PV power plant under...... of a 200 MW PV power plant demonstrate that the proposed method can ensure the rated power transfer of PV power plant with the SCR of 1.25, provided that the PV inverters are operated with the minimal PF=0.9.......This paper analyzes the power transfer limitation of the PV power plant under the ultra-weak grid condition, i.e., when the Short-Circuit Ratio (SCR) is close to 1. It explicitly identifies that a minimum SCR of 2 is required for the PV power plant to deliver the rated active power when operating...

  17. Wolf Search Algorithm for Solving Optimal Reactive Power Dispatch Problem

    Directory of Open Access Journals (Sweden)

    Kanagasabai Lenin

    2015-03-01

    Full Text Available This paper presents a new bio-inspired heuristic optimization algorithm called the Wolf Search Algorithm (WSA for solving the multi-objective reactive power dispatch problem. Wolf Search algorithm is a new bio – inspired heuristic algorithm which based on wolf preying behaviour. The way wolves search for food and survive by avoiding their enemies has been imitated to formulate the algorithm for solving the reactive power dispatches. And the speciality  of wolf is  possessing  both individual local searching ability and autonomous flocking movement and this special property has been utilized to formulate the search algorithm .The proposed (WSA algorithm has been tested on standard IEEE 30 bus test system and simulation results shows clearly about the good performance of the proposed algorithm .

  18. Modified artificial bee colony algorithm for reactive power optimization

    Science.gov (United States)

    Sulaiman, Noorazliza; Mohamad-Saleh, Junita; Abro, Abdul Ghani

    2015-05-01

    Bio-inspired algorithms (BIAs) implemented to solve various optimization problems have shown promising results which are very important in this severely complex real-world. Artificial Bee Colony (ABC) algorithm, a kind of BIAs has demonstrated tremendous results as compared to other optimization algorithms. This paper presents a new modified ABC algorithm referred to as JA-ABC3 with the aim to enhance convergence speed and avoid premature convergence. The proposed algorithm has been simulated on ten commonly used benchmarks functions. Its performance has also been compared with other existing ABC variants. To justify its robust applicability, the proposed algorithm has been tested to solve Reactive Power Optimization problem. The results have shown that the proposed algorithm has superior performance to other existing ABC variants e.g. GABC, BABC1, BABC2, BsfABC dan IABC in terms of convergence speed. Furthermore, the proposed algorithm has also demonstrated excellence performance in solving Reactive Power Optimization problem.

  19. Autonomously managed electrical power systems

    Science.gov (United States)

    Callis, Charles P.

    1986-01-01

    The electric power systems for future spacecraft such as the Space Station will necessarily be more sophisticated and will exhibit more nearly autonomous operation than earlier spacecraft. These new power systems will be more reliable and flexible than their predecessors offering greater utility to the users. Automation approaches implemented on various power system breadboards are investigated. These breadboards include the Hubble Space Telescope power system test bed, the Common Module Power Management and Distribution system breadboard, the Autonomusly Managed Power System (AMPS) breadboard, and the 20 kilohertz power system breadboard. Particular attention is given to the AMPS breadboard. Future plans for these breadboards including the employment of artificial intelligence techniques are addressed.

  20. Reactive power control of wind farm using facts devices

    International Nuclear Information System (INIS)

    Ashfaq, S.; Arif, A.; Shakeel, A.; Mahmood, T.

    2014-01-01

    Wind energy is an attainable option to complement other types of pollution-free green generation Grid connections of renewable energy resources are vital if they are to be effectively exploited, but grid connection brings problems of voltage fluctuation and harmonic distortion. FACTs devices are one of the power electronics revolutions to improve voltage profile, system stability, and reactive power control and to reduce transmission losses. The studied system here is a variable speed wind generation system based on Induction Generator (IG) with integration of different FACTs controllers in the wind farm. To harness the wind power efficiently the most reliable and expensive system in the present era is grid connected doubly fed induction generator. Induction generator with FACTs devices is a suitable economical replacement. The suggested scheme is implemented in MATLAB Simulink with real time parameters of GHARO wind power plant in Sind, and corresponding results and output waveforms proves the potential strength of proposed methodology. (author)

  1. A Hybrid Optimization Method for Reactive Power and Voltage Control Considering Power Loss Minimization

    DEFF Research Database (Denmark)

    Liu, Chengxi; Qin, Nan; Bak, Claus Leth

    2015-01-01

    This paper proposes a hybrid optimization method to optimally control the voltage and reactive power with minimum power loss in transmission grid. This approach is used for the Danish automatic voltage control (AVC) system which is typically a non-linear non-convex problem mixed with both...

  2. Autonomously managed high power systems

    International Nuclear Information System (INIS)

    Weeks, D.J.; Bechtel, R.T.

    1985-01-01

    The need for autonomous power management capabilities will increase as the power levels of spacecraft increase into the multi-100 kW range. The quantity of labor intensive ground and crew support consumed by the 9 kW Skylab cannot be afforded in support of a 75-300 kW Space Station or high power earth orbital and interplanetary spacecraft. Marshall Space Flight Center is managing a program to develop necessary technologies for high power system autonomous management. To date a reference electrical power system and automation approaches have been defined. A test facility for evaluation and verification of management algorithms and hardware has been designed with the first of the three power channel capability nearing completion

  3. Systemwide Power Management with Argo

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth, Daniel; Patki, Tapasya; Perarnau, Swann; Seo, Sangmin; Yoshii, Kazutomo; Hoffmann, Henry; Schulz, Martin; Beckman, Pete

    2016-05-23

    The Argo project is a DOE initiative for designing a modular operating system/runtime for the next generation of supercomputers. A key focus area in this project is power management, which is one of the main challenges on the path to exascale. In this paper, we discuss ideas for systemwide power management in the Argo project. We present a hierarchical and scalable approach to maintain a power bound at scale, and we highlight some early results.

  4. Reactivity control of nuclear power reactors: new options

    International Nuclear Information System (INIS)

    Alcala, F.

    1984-01-01

    Some actual aspects (referring to economy, non-proliferation and environmental impact) of nuclear power reactors has been analyzed from the point of view of the reactivity control physics. Specially studied have been the physical mechanisms related with the spectral shift control method and their general positive effects on those aspects. The analysis carried out suggested the application of the above method of control to reactors with non-hydrogenous fuel cells, which are mainly characterized by their high moderator/fuel ratio. Finally three different types of such fuel cells are presented and some results about one of them (belonging to a PHWR controlled by graphite rods) are given. (author)

  5. Basic study on dynamic reactive-power control method with PV output prediction for solar inverter

    Directory of Open Access Journals (Sweden)

    Ryunosuke Miyoshi

    2016-01-01

    Full Text Available To effectively utilize a photovoltaic (PV system, reactive-power control methods for solar inverters have been considered. Among the various methods, the constant-voltage control outputs less reactive power compared with the other methods. We have developed a constant-voltage control to reduce the reactive-power output. However, the developed constant-voltage control still outputs unnecessary reactive power because the control parameter is constant in every waveform of the PV output. To reduce the reactive-power output, we propose a dynamic reactive-power control method with a PV output prediction. In the proposed method, the control parameter is varied according to the properties of the predicted PV waveform. In this study, we performed numerical simulations using a distribution system model, and we confirmed that the proposed method reduces the reactive-power output within the voltage constraint.

  6. Efficient Reactive Power Compensation Algorithm for Distribution Network

    Directory of Open Access Journals (Sweden)

    J. Jerome

    2017-12-01

    Full Text Available The use of automation and energy efficient equipment with electronic control would greatly improve industrial production.  These new devices are more sensitive to supply voltage deviation and the characteristics of the power system that was previously ignored are now very important. Hence the benefits of distribution automation have been widely acknowledged in recent years. This paper proposes an efficient load flow solution technique extended to find optimum location for reactive power compensation and network reconfiguration for planning and day-to-day operation of distribution networks.  This is required as a part of the distribution automation system (DAS for taking various control and operation decisions.  The method exploits the radial nature of the network and uses forward and backward propagation technique to calculate branch currents and node voltages.  The proposed method has been tested to analyze several practical distribution networks of various voltage levels and also having high R/X ratio.

  7. Stochastic reactive power market with volatility of wind power considering voltage security

    International Nuclear Information System (INIS)

    Kargarian, A.; Raoofat, M.

    2011-01-01

    While wind power generation is growing rapidly around the globe; its stochastic nature affects the system operation in many different aspects. In this paper, the impact of wind power volatility on the reactive power market is taken into account. The paper presents a novel stochastic method for optimal reactive power market clearing considering voltage security and volatile nature of the wind. The proposed optimization algorithm uses a multiobjective nonlinear programming technique to minimize market payment and simultaneously maximize voltage security margin. Considering a set of probable wind speeds, in the first stage, the proposed algorithm seeks to minimize expected system payment which is summation of reactive power payment and transmission loss cost. The object of the second stage is maximization of expected voltage security margin to increase the system loadability and security. Finally, in the last stage, a multiobjective function is presented to schedule the stochastic reactive power market using results of two previous stages. The proposed algorithm is applied to IEEE 14-bus test system. As a benchmark, Monte Carlo Simulation method is utilized to simulate the actual market of given period of time to evaluate results of the proposed algorithm, and satisfactory results are achieved. -- Highlights: →The paper proposes a new algorithm for stochastic reactive power market clearing. →The stochastic nature of the wind which impacts the system operation and market clearing process, is taken into account. →The paper suggests an expected voltage stability margin and optimizes it in conjunction with expected total market payment. →To clear the market with two mentioned objective functions, a three-stage multiobjective nonlinear programming is implemented. →Also, a simple method is suggested to determine a suitable priority coefficient between two individual objective functions.

  8. Reactive power influence on the thermal cycling of multi-MW wind power inverter

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2012-01-01

    converter system are first presented at different wind speeds. Furthermore, the interaction between paralleled converter systems in a wind park is also considered and analyzed. By controlling the reactive power circulated among paralleled converters, a new concept is then proposed to stabilize the thermal...

  9. Electrical engineering unit for the reactive power control of the load bus at the voltage instability

    Science.gov (United States)

    Kotenev, A. V.; Kotenev, V. I.; Kochetkov, V. V.; Elkin, D. A.

    2018-01-01

    For the purpose of reactive power control error reduction and decrease of the voltage sags in the electric power system caused by the asynchronous motors started the mathematical model of the load bus was developed. The model was built up of the sub-models of the following elements: a transformer, a transmission line, a synchronous and an asynchronous loads and a capacitor bank load, and represents the automatic reactive power control system taking into account electromagnetic processes of the asynchronous motors started and reactive power changing of the electric power system elements caused by the voltage fluctuation. The active power/time and reactive power/time characteristics based on the recommended procedure of the equivalent electric circuit parameters calculation were obtained. The derived automatic reactive power control system was shown to eliminate the voltage sags in the electric power system caused by the asynchronous motors started.

  10. Distributed control of hybrid AC microgrids with dynamic active and reactive power capacity tuning

    DEFF Research Database (Denmark)

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

    2012-01-01

    Microgrids comprise of emerging generation technologies such as fuel cell, solar PV, wind turbine generator, storage and loads. They can, in principle, operate at different voltages and frequencies. Tying them either to the mains grid or among themselves would certainly require some interlinking...... power converters, whose control should preferably be done autonomously without demanding communication links. This paper proposes distributed control for power management between two Microgrids interlinked through inverters. The control scheme aims to reduce the reactive power loading stress on DERs...... and also allows active power transfer from overloaded grid to under- loaded grid. The performance of proposed control has been verified in simulation and through a scaled-down experimental system....

  11. Reactive power dispatch considering voltage stability with seeker optimization algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Chaohua; Chen, Weirong; Zhang, Xuexia [The School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Zhu, Yunfang [Department of Computer and Communication Engineering, E' mei Campus, Southwest Jiaotong University, E' mei 614202 (China)

    2009-10-15

    Optimal reactive power dispatch (ORPD) has a growing impact on secure and economical operation of power systems. This issue is well known as a non-linear, multi-modal and multi-objective optimization problem where global optimization techniques are required in order to avoid local minima. In the last decades, computation intelligence-based techniques such as genetic algorithms (GAs), differential evolution (DE) algorithms and particle swarm optimization (PSO) algorithms, etc., have often been used for this aim. In this work, a seeker optimization algorithm (SOA) based method is proposed for ORPD considering static voltage stability and voltage deviation. The SOA is based on the concept of simulating the act of human searching where search direction is based on the empirical gradient by evaluating the response to the position changes and step length is based on uncertainty reasoning by using a simple Fuzzy rule. The algorithm's performance is studied with comparisons of two versions of GAs, three versions of DE algorithms and four versions of PSO algorithms on the IEEE 57 and 118-bus power systems. The simulation results show that the proposed approach performed better than the other listed algorithms and can be efficiently used for the ORPD problem. (author)

  12. Microgrid Reactive and Harmonic Power Sharing Using Enhanced Virtual Impedance

    DEFF Research Database (Denmark)

    He, Jinwei; Wei Li, Yun; Guerrero, Josep M.

    2013-01-01

    To address the load sharing problem in islanding microgrids, this paper proposes an improved approach which regulates the distributed generation (DG) unit interfacing virtual impedance at fundamental and selected harmonic frequencies. In contrast to the conventional virtual impedance control where...... only a line current feed-forward term is added to the DG voltage reference, the proposed virtual impedances at fundamental and harmonic frequencies are realized using DG line current and point of common coupling (PCC) voltage feed-forward terms, respectively. With this modification, the mismatched DG...... feeder impedances can be properly compensated, resulting in accurate reactive and harmonic power sharing at the same time. In addition, this paper shows that the microgrid PCC harmonic voltages can be mitigated by reducing the magnitude of DG unit equivalent harmonic impedance. Finally, an improved...

  13. Robust Adaptive Reactive Power Control for Doubly Fed Induction Generator

    Directory of Open Access Journals (Sweden)

    Huabin Wen

    2014-01-01

    Full Text Available The problem of reactive power control for mains-side inverter (MSI in doubly fed induction generator (DFIG is studied in this paper. To accommodate the modelling nonlinearities and inherent uncertainties, a novel robust adaptive control algorithm for MSI is proposed by utilizing Lyapunov theory that ensures asymptotic stability of the system under unpredictable external disturbances and significant parametric uncertainties. The distinguishing benefit of the aforementioned scheme consists in its capabilities to maintain satisfactory performance under varying operation conditions without the need for manually redesigning or reprogramming the control gains in contrast to the commonly used PI/PID control. Simulations are also built to confirm the correctness and benefits of the control scheme.

  14. 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

  15. An islanding microgrid reactive power sharing scheme enhanced by programmed virtual impedances

    DEFF Research Database (Denmark)

    He, Jinwei; Li, Yun Wei; Guerrero, Josep M.

    2012-01-01

    harmonic currents. With the knowledge of feeder impedances, reactive power sharing performance can be enhanced by the regulation of DG unit output virtual impedance. The proposed method realizes accurate real and reactive power sharing in proportion to DG unit rated power. Simulated and experimental...

  16. Establishing the long-term fuel management scheme using point reactivity model

    International Nuclear Information System (INIS)

    Park, Yong-Soo; Kim, Jae-Hak; Lee, Young-Ouk; Song, Jae-Woong; Zee, Sung-Kyun

    1994-01-01

    A new approach to establish the long-term fuel management scheme is presented in this paper. The point reactivity model is used to predict the core average reactivity. An attempt to calculate batchwise power fraction is introduced through the two-dimensional nodal power algorithm based on the modified one-group diffusion equation and the number of fuel assemblies on the core periphery. Suggested is an empirical formula to estimate the radial leakage reactivity with ripe core design experience reflected. This approach predicts the cycle lengths and the discharge burnups of individual fuel batches up to an equilibrium core when the proper input data such as batch enrichment, batch size, type and content of burnable poison and reloading strategies are given. Eight benchmark calculations demonstrate that the new approach used in this study is reasonably accurate and highly efficient for the purpose of scoping calculation when compared with design code predictions. (author)

  17. Ancillary reactive power service allocation cost in deregulated markets: a methodology

    International Nuclear Information System (INIS)

    Hernandez, J. Horacio Tovar; Jimenez-Guzman, Miguel; Gutierrez-Alcaraz, Guillermo

    2005-01-01

    This paper presents a methodology to allocate reactive power costs in deregulated markets. Reactive power supply service is decomposed into voltage regulation and reactive power spinning reserve. The proposed methodology is based on sensitivities and the postage-stamp method in order to allocate the total costs service among all participants. With the purpose of achieving this goal, the system operator identifies voltage support and/or reactive power requirements, and looks out for suitable providers. One case study is presented here to illustrate the methodology over a simplified southeastern Mexican grid. (Author)

  18. Advanced configuration of hybrid passive filter for reactive power and harmonic compensation

    OpenAIRE

    Kececioglu, O. Fatih; Acikgoz, Hakan; Sekkeli, Mustafa

    2016-01-01

    Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. ...

  19. Advanced configuration of hybrid passive filter for reactive power and harmonic compensation.

    Science.gov (United States)

    Kececioglu, O Fatih; Acikgoz, Hakan; Sekkeli, Mustafa

    2016-01-01

    Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. Simulation results show that performance of reactive power and harmonic compensation with advanced hybrid passive filter is better than conventional hybrid passive filters.

  20. Photovoltaic solar system connected to the electric power grid operating as active power generator and reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, F.L.; Moraes, A.J.; Guimaraes, G.C.; Sanhueza, S.M.R.; Vaz, A.R. [Federal University of Uberlandia (UFU), MG (Brazil)

    2009-07-01

    In the case of photovoltaic solar systems (PV) acting as a distributed generation (DG), the DC energy obtained is fed through the power-conditioning unit (inverter) to the grid. The majority of contemporary inverters used in DG systems are current source inverters (CSI) operating at unity power factor. If, however, we assume that voltage source inverters (VSI) can be utilized instead of CSI, we can generate reactive power commensurate with the remaining unused capacity at any given point in time. According to the theory of instantaneous power, the reactive and active power of inverter can be regulated by changing the amplitude and the phase of the output voltage of the inverter. Based on this theory, the active power output and the reactive power compensation (RPC) of the system are realized simultaneously. When the insolation is weak or the PV modules are inoperative at night, the RPC feature of PV system can still be used to improve the utilization factor of the inverter. The MATLAB simulation results validate the feasibility of the method. (author)

  1. Local Dynamic Reactive Power for Correction of System Voltage Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

    2008-12-01

    Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results

  2. Radial distribution of power starting from the reactivity using nodal schemes of second and third order

    International Nuclear Information System (INIS)

    Delfin L, A.; Alonso V, G.; Valle G, E. del

    2003-01-01

    In this work two nodal schemes of finite element are presented, one of second and the other of third order of accurate that allow to determine the radial distribution of power starting from the corresponding reactivities.The schemes here developed were obtained taking as starting point the equation developed by Driscoll et al, the one which is based on the diffusion approach of 1-1/2 energy groups. This equation relates the power fraction of an assemble with their reactivity and with the power fractions and reactivities of the assemblies that its surround it. Driscoll and collaborators they solve in form approximate such equation supposing that the reactivity of each assemble it is but a lineal function of the burnt one of the fuel. The spatial approach carries out it with the classic technique of finite differences centered in mesh. Nevertheless that the algebraic system to which its arrive it can be solved without more considerations introduce some additional suppositions and adjustment parameters that it allows them to predict results comparable to those contributed by three dimensions analysis and this way to reduce the one obtained error when its compare their results with those of a production code like CASMO. Also in the two schemes that here are presented the same approaches of Driscoll were used being obtained errors of the one 10% and of 5% for the second schemes and third order respectively for a test case that it was built starting from data of the Cycle 1 of the Unit 1 of the Laguna Verde Nucleo electric plant. These errors its were obtained when comparing with a computer program based on the matrix response method. It is sought to have this way a quick and efficient tool for the multicycle analysis in the fuel management. However, this model presents problems in the appropriate prediction of the average burnt of the nucleus and of the burnt one by lot. (Author)

  3. A method and system for power management

    NARCIS (Netherlands)

    Burchard, Arthur Tadeusz; Goossens, Koos Gerard Willen; Milutinovic, A.; Molnos, Anca Mariana; Steffens, Elisabeth Francisca Maria

    2009-01-01

    A method and system for power management is provided. To control power supplied to a second electronic device (106), an electronic system (100) comprises a power management subsystem (110), a first electronic device (102); The power management subsystem (110) monitors the power consumed by the first

  4. Power Electronics Thermal Management | Transportation Research | NREL

    Science.gov (United States)

    Power Electronics Thermal Management Power Electronics Thermal Management A photo of water boiling in liquid cooling lab equipment. Power electronics thermal management research aims to help lower the investigates and develops thermal management strategies for power electronics systems that use wide-bandgap

  5. An OPF based approach for assessing the minimal reactive power support for generators in deregulated power systems

    International Nuclear Information System (INIS)

    Wu, H.; Yu, C.W.; Xu, N.; Lin, X.J.

    2008-01-01

    Reactive power support is an important ancillary service for secure and reliable operation in power markets. It has recently been recognized that the reactive power support for a generator has two components: one for supporting its own real power transmission and the other for supplying reactive demand, improving system security, and controlling system voltage; and that only the second part should receive financial compensation in competitive power markets. This makes the problem of separating these two components a new focus of current research. An OPF based reactive power optimization model along with a power flow tracing based method is proposed in this paper to tackle this problem. The methodology is tested on four test systems. Detailed analysis of the results of the 39-bus test system is reported. (author)

  6. Remuneration of the reactive power in the Argentinean supply market; Remuneracao da potencia reativa no mercado de suprimento argentino

    Energy Technology Data Exchange (ETDEWEB)

    Kerszberg, Ernesto M; Dravnovsky, Mario Carlos [Administradora del Mercado Mayorista Eletrico S.A. (Argentina)

    1996-05-01

    This work presents the standards and legislation about power reactive consumption by involved agents in the market electric power supply. It discusses how to remunerate this reactive and the compromises among the actors of the power electric system

  7. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  8. Guidelines for Distribution System Operators on Reactive Power Provision by Electric Vehicles in Low Voltage Grids

    DEFF Research Database (Denmark)

    Zecchino, Antonio; Marinelli, Mattia; Træholt, Chresten

    2017-01-01

    The increasing success of electric vehicles is bringing new technical challenges to power system operators. This work intends to provide guidelines for distribution system operators in terms of reactive power requirements when evaluating and authorizing electric vehicles supply equipment with fast...... the amount of reactive power that an individual electric vehicle is expected to provide when connected to a low voltage feeder, in order to benefit of the desired voltage rise effect in comparison to the case of unitary power factor....

  9. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  10. Extended reactivity trace curves for nuclear power control with no power shooting

    International Nuclear Information System (INIS)

    Ratemi, W. M.; Elbuni, M. S.

    1995-01-01

    This paper introduces a new concept of reactivity trace curve (RTC) for nuclear power control with no power shooting. The concept is based on recent work of bernard et al. on the dynamic period of nuclear reactors. RTC-method is simulated for both a static effective decay constant corresponding to a one-group delayed neutrons model, and a dynamic effective decay constant corresponding to a six-group delayed neutrons model. A fitting to the RTC of a six-group reactor model resulted in a closed from formula for the RTC that couples the effect of both static and dynamic decay constants. Hence, introducing two 'fingerprints' for the reactor in concern to identify a closed from RTC formula capable of controlling the reactor power. Integration of the RTC with control rod integral curves results in the ρ-z-t diagram. This diagram relates the amount of recommended reactivity (RTC), the position of control rod, and the time required for power control. 8 figs

  11. Extended reactivity trace curves for nuclear power control with no power shooting

    Energy Technology Data Exchange (ETDEWEB)

    Ratemi, W M; Elbuni, M S [Faculty of engineering, Al Fateh universty Tripoli (Libyan Arab Jamahiriya)

    1995-10-01

    This paper introduces a new concept of reactivity trace curve (RTC) for nuclear power control with no power shooting. The concept is based on recent work of bernard et al. on the dynamic period of nuclear reactors. RTC-method is simulated for both a static effective decay constant corresponding to a one-group delayed neutrons model, and a dynamic effective decay constant corresponding to a six-group delayed neutrons model. A fitting to the RTC of a six-group reactor model resulted in a closed from formula for the RTC that couples the effect of both static and dynamic decay constants. Hence, introducing two `fingerprints` for the reactor in concern to identify a closed from RTC formula capable of controlling the reactor power. Integration of the RTC with control rod integral curves results in the {rho}-z-t diagram. This diagram relates the amount of recommended reactivity (RTC), the position of control rod, and the time required for power control. 8 figs.

  12. Operational experience with reactive power control methods optimized for tokamak power supplies

    International Nuclear Information System (INIS)

    Sihler, C.; Huart, M.; Kaesemann, C.-P.; Streibl, B.

    2003-01-01

    The power and energy of the ASDEX Upgrade (AUG) tokamak are provided by two separate 10.5 kV, 110-85 Hz networks based on the flywheel generators EZ3-EZ4 in addition to the generator EZ2 dedicated to the toroidal field coil. The 10.5 kV networks supply the thyristor converters allowing fast control of the DC currents in the AUG poloidal field coils. Two methods for improving the load power factor in the present experimental campaign of AUG have been investigated, namely the control of the phase-to-neutral voltage in thyristor converters fitted with neutral thyristors, such as the new 145 MVA modular thyristor converter system (Group 6), and reactive power control achieved by means of static VAr compensators (SVC). The paper shows that reliable compensation up to 90 MVAr was regularly achieved and that electrical transients in SVC modules can be kept at an acceptable level. The paper will discuss the results from the reactive power reduction by SVC and neutral thyristor control and draw a comparative conclusion

  13. An accurate reactive power control study in virtual flux droop control

    Science.gov (United States)

    Wang, Aimeng; Zhang, Jia

    2017-12-01

    This paper investigates the problem of reactive power sharing based on virtual flux droop method. Firstly, flux droop control method is derived, where complicated multiple feedback loops and parameter regulation are avoided. Then, the reasons for inaccurate reactive power sharing are theoretically analyzed. Further, a novel reactive power control scheme is proposed which consists of three parts: compensation control, voltage recovery control and flux droop control. Finally, the proposed reactive power control strategy is verified in a simplified microgrid model with two parallel DGs. The simulation results show that the proposed control scheme can achieve accurate reactive power sharing and zero deviation of voltage. Meanwhile, it has some advantages of simple control and excellent dynamic and static performance.

  14. An Improved Droop Control Strategy for Reactive Power Sharing in Islanded Microgrid

    DEFF Research Database (Denmark)

    Han, Hua; Liu, Yao; Sun, Yao

    2015-01-01

    For microgrid in islanded operation, due to the effects of mismatched line impedance, the reactive power could not be shared accurately with the conventional droop method. To improve the reactive power sharing accuracy, this paper proposes an improved droop control method. The proposed method...... in output voltage amplitude. Therefore, the voltage recovery operation is proposed to compensate the decrease. The needed communication in this method is very simple, and the plug-and-play is reserved. Simulations and experimental results show that the improved droop controller can share load active...... and reactive power, improve the power quality of the microgrid, and also have a good dynamic performance....

  15. Framework for the analysis of reactive power dispatch in energy pools

    International Nuclear Information System (INIS)

    Salgado, R.S.; Irving, M.R.

    2004-01-01

    This paper proposes a framework for the simulation and analysis of the reactive power distribution in electric energy markets of the pool type. Firstly, the analytical formulation of the OPF problem, with three optional performance indexes for the reactive power dispatch, is discussed. These OPF objectives are used to determine the reactive power distribution for a given active power dispatch (obtained through merit-order strategy, for instance). An allocation strategy is used to assess the participation of each power system agent in the loss/reactive power distribution. This strategy uses the premise of co-operative game theory. Numerical results obtained with the Ward-Hale 6-bus test system illustrate the main aspects of the proposed methodology. (author)

  16. Strategies for reactive power control in wind farms with STATCOM

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Gonzalez, Francisco [Catalonia Institute for Energy Research (IREC), Barcelona (Spain); Martinez-Rojas, Marcela [Centre d' Innovacio Tecnologica en Convertidors Estatics i Accionaments (CITCEA-UPC), Barcelona (Spain). Dept. d' Enginyeria Electrica; Sumper, Andreas; Gomis-Bellmunt, Oriol [Catalonia Institute for Energy Research (IREC), Barcelona (Spain); Centre d' Innovacio Tecnologica en Convertidors Estatics i Accionaments (CITCEA-UPC), Barcelona (Spain). Dept. d' Enginyeria Electrica

    2010-07-01

    This paper presents two strategies for reactive current control in wind farms with STATCOM under fault ride-through (FRT) situations. First, the technical requirements of the Spanish and German grid codes related to the reactive current under FRT situations are presented. Second, STATCOM and its control system are introduced. Third, the modeling done of the wind farm, the STATCOM, and the network are presented. Finally, control strategies for reactive current delivered by the park to the network under FRT situations are shown. The result of the implementation of each control strategy is shown by simulation. (orig.)

  17. [Risk Management of HBV Reactivation: Construction of Check System].

    Science.gov (United States)

    Tanaka, Yasuhito

    2015-09-01

    In recent years, reactivation of HBV in patients receiving cancer chemotherapy or immunosuppressive therapy has been a problem. Generally, HBV-DNA levels are elevated prior to HBsAg concentration, and then hepatic dysfunction is observed in the process of hepatitis by HBV reactivation. Therefore, the monitoring of HBV-DNA is useful for the prediction of hepatic dysfunction, and nucleoside/nucleoside analogue (NA) administration is able to prevent this HBV reactivation. According to these facts, "Guidelines for the Prevention of HBV Reactivation in Patients Receiving Immunosuppressive Therapy or Chemotherapy", 2009 (revised as "JSH Guidelines for the Management of Hepatitis B Virus Infection", 2013) is established, and the diagnostic algorithm of HBsAg, anti-HBc, anti-HBs, and HBV-DNA has relevant descriptions. Combination therapy with rituximab and steroid for malignant lymphoma has a high risk of leading to fulminant hepatitis and, consequently, the guidelines are widely followed in such cases. We introduced the improvement of electronic medical recording and ordering systems in collaboration with hepatologists, and such a system has been widely used. Although the monitoring of HBV-DNA levels is required every 1-3 months, the guidelines are not followed strictly in cases such as rheumatoid disease and solid tumors only with chemotherapy or steroid treatment. Since a DNA assay is complicated and expensive, cost-effective, time-saving, and highly sensitive/specific measurements are required as well. Therefore, Lumipulse HBsAg-HQ (CLIA method) with high sensitivity is expected to be used for the monitoring of HBV reactivation.

  18. Comprehensive Reactive Power Support of DFIG Adapted to Different Depth of Voltage Sags

    Directory of Open Access Journals (Sweden)

    Yangwu Shen

    2017-06-01

    Full Text Available The low voltage ride-through (LVRT capability of the doubly-fed induction generator (DFIG significantly impacts upon the integration of wind power into the power grid. This paper develops a novel comprehensive control strategy to enhance the LVRT and reactive power support capacities of the DFIG by installing the energy storage system (ESS. The ESS is connected to the DC-link capacitor of the DFIG and used to regulate the DC-link voltage during normal or fault operations. The unbalanced power between the captured wind power and the power injected to the grid during the transient process is absorbed or compensated by the ESS. The rotor-side converter (RSC is used to control the maximum power production and the grid-side converter (GSC is used to control the reactive power before participating in the voltage support. When the supply voltage continues to drop, the rotor speed is increased by controlling the RSC to realize the LVRT capability and help the GSC further enhance the reactive power support capability. The capacity of the GSC is dedicated to injecting the reactive power to the grid. An auxiliary transient pitch angle controller is proposed to protect the generator’s over speed. Both RSC and GSC act as reactive power sources to further enhance the voltage support capability with serious voltage sags. Simulations based on a single-machine infinite-bus power system verify the effectiveness of the developed comprehensive control strategy.

  19. European Clearinghouse. Incidents related to reactivity management. Contributing factors, failure modes and corrective actions

    International Nuclear Information System (INIS)

    Bruynooghe, Christiane; Noel, Marc

    2009-01-01

    This work is part of the European Clearinghouse on Nuclear Power Plant Operational Experience Feedback (NPP-OEF) activity carried out at the Joint Research Centre/Institute for Energy (JRC/IE) with the participation of nine EU Regulatory Authorities. It investigates the 1999 Shika-1 criticality event together with other shortcomings in reactivity management reported to the IAE4 Incident Reporting System in the period 1981-2008. The aim of the work was to identify reactivity control failure modes, reactor status and corrective actions. Initiating factors and associated root causes were also analysed. Five of the 7 factors identified for all events were present in the 1999 Shika-1 event where criticality has been unexpectedly reached and maintained during 15 minutes. Most of the events resulted in changes in procedures, material or staff and management training. The analysis carried out put in evidence that in several instances appropriate communication based on operational experience feedback would have prevented incident to occur. This paper also summarises the action taken at power plants and by the regulatory bodies in different countries to avoid repetition of similar events. It identifies insights that might be useful to reduce the likelihood of operational events caused by shortcomings in reactivity management. (orig.)

  20. Measurements of the Reactivity Properties of the Aagesta Nuclear Power Reactor at Zero Power

    Energy Technology Data Exchange (ETDEWEB)

    Bernander, G

    1967-07-15

    The moderator level and temperature coefficients of reactivity and control rod differential reactivity worths have been determined at zero power by means of period measurements. The moderator level coefficient and the corresponding critical level have been measured for the 32, 68 and 136 fuel assembly cores at room temperature for cores with and without control rods. From these results the worths of control rods have been derived. HETERO calculations give up to 15 % lower values than the experimental results. The cold fresh core has an excess reactivity of 9.0 {+-} 0.2 %. The temperature coefficient and differential control rod worths were measured for the fully loaded core with filled tank in the temperature range between 30 and 210 deg C. Critical positions as a function of temperature were obtained for the corresponding control rod groups. No relevant calculations of the temperature coefficient for comparison with the experimental values have yet been made, but the experimental results together with measured critical control rod positions give good opportunities to check calculational programs. HETERO has been shown in these cases to reproduce differential control rod worths and critical positions fairly well. However, a certain underestimation of the rod effectiveness is quite noticeable. The relative increase in control rod effectiveness with a temperature change from 20 to 220 deg C has been estimated to be 0.29 {+-} 0.06.

  1. Power quality load management for large spacecraft electrical power systems

    Science.gov (United States)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  2. Impact of Reactive Power Injection Outside Feed-In Hours on the Reliability of Photovoltaic Inverters

    DEFF Research Database (Denmark)

    Anurag, Anup; Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    , the analysis enables the translation from long-term mission profiles to device thermal loading, considering the operation at night. An analytical lifetime model is then used for lifetime quantization based on the Palgrem Miner rule. Thereafter, considering the lifetime reduction of the PV inverter......Current energy paradigm of mixed renewables seems to urgently require reactive power provision at various feed-in points of the utility grid. Photovoltaic (PV) inverters are able to provide reactive power in a decentralized manner at the grid-connection point even outside active power feed......-in operation, especially at night. This serves as a motivation for utilizing the PV inverters at night for reactive power compensation. Thus, a detailed analysis on the impact of reactive power injection by PV inverters outside feed-in operation on the thermal performance and also the reliability is performed...

  3. Multi-objective Reactive Power Optimization Based on Improved Particle Swarm Algorithm

    Science.gov (United States)

    Cui, Xue; Gao, Jian; Feng, Yunbin; Zou, Chenlu; Liu, Huanlei

    2018-01-01

    In this paper, an optimization model with the minimum active power loss and minimum voltage deviation of node and maximum static voltage stability margin as the optimization objective is proposed for the reactive power optimization problems. By defining the index value of reactive power compensation, the optimal reactive power compensation node was selected. The particle swarm optimization algorithm was improved, and the selection pool of global optimal and the global optimal of probability (p-gbest) were introduced. A set of Pareto optimal solution sets is obtained by this algorithm. And by calculating the fuzzy membership value of the pareto optimal solution sets, individuals with the smallest fuzzy membership value were selected as the final optimization results. The above improved algorithm is used to optimize the reactive power of IEEE14 standard node system. Through the comparison and analysis of the results, it has been proven that the optimization effect of this algorithm was very good.

  4. Multiagent-Based Reactive Power Sharing and Control Model for Islanded Microgrids

    DEFF Research Database (Denmark)

    Chen, Feixiong; Chen, Minyou; Li, Qiang

    2016-01-01

    of the control model, in which the uncertainty of intermittent DGs, variations in load demands, as well as impacts of time delays are considered. The simulation results demonstrate the eectiveness of the control model in proportional reactive power sharing, and the plug and play capability of the control model......In islanded microgrids (MGs), the reactive power cannot be shared proportionally among distributed generators (DGs) with conventional droop control, due to the mismatch in feeder impedances. For the purpose of proportional reactive power sharing, a multiagent system (MAS) based distributed control...

  5. Real-Time Reactive Power Distribution in Microgrids by Dynamic Programing

    DEFF Research Database (Denmark)

    Levron, Yoash; Beck, Yuval; Katzir, Liran

    2017-01-01

    In this paper a new real-time optimization method for reactive power distribution in microgrids is proposed. The method enables location of a globally optimal distribution of reactive power under normal operating conditions. The method exploits the typical compact structure of microgrids to obtain...... combination of reactive powers, by means of dynamic programming. Since every single step involves a one-dimensional problem, the complexity of the solution is only linear with the number of clusters, and as a result, a globally optimal solution may be obtained in real time. The paper includes the results...

  6. Distributed Reactive Power Control based Conservation Voltage Reduction in Active Distribution Systems

    Directory of Open Access Journals (Sweden)

    EMIROGLU, S.

    2017-11-01

    Full Text Available This paper proposes a distributed reactive power control based approach to deploy Volt/VAr optimization (VVO / Conservation Voltage Reduction (CVR algorithm in a distribution network with distributed generations (DG units and distribution static synchronous compensators (D-STATCOM. A three-phase VVO/CVR problem is formulated and the reactive power references of D-STATCOMs and DGs are determined in a distributed way by decomposing the VVO/CVR problem into voltage and reactive power control. The main purpose is to determine the coordination between voltage regulator (VR and reactive power sources (Capacitors, D-STATCOMs and DGs based on VVO/CVR. The study shows that the reactive power injection capability of DG units may play an important role in VVO/CVR. In addition, it is shown that the coordination of VR and reactive power sources does not only save more energy and power but also reduces the power losses. Moreover, the proposed VVO/CVR algorithm reduces the computational burden and finds fast solutions. To illustrate the effectiveness of the proposed method, the VVO/CVR is performed on the IEEE 13-node test system feeder considering unbalanced loading and line configurations. The tests are performed taking the practical voltage-dependent load modeling and different customer types into consideration to improve accuracy.

  7. Review of Active and Reactive Power Sharing Strategies in Hierarchical Controlled Microgrids

    DEFF Research Database (Denmark)

    Han, Yang; Li, Hong; Shen, Pan

    2017-01-01

    Microgrids consist of multiple parallel-connected distributed generation (DG) units with coordinated control strategies, which are able to operate in both grid-connected and islanded mode. Microgrids are attracting more and more attention since they can alleviate the stress of main transmission...... systems, reduce feeder losses, and improve system power quality. When the islanded microgrids are concerned, it is important to maintain system stability and achieve load power sharing among the multiple parallel-connected DG units. However, the poor active and reactive power sharing problems due...... in this paper for active power sharing. Moreover, nonlinear and unbalanced loads could further affect the reactive power sharing when regulating the active power, and it is difficult to share the reactive power accurately only by using the enhanced virtual impedance method. Therefore, the hierarchical control...

  8. Improvement of the dynamic response of the ITER Reactive Power Compensation system

    International Nuclear Information System (INIS)

    Finotti, Claudio; Gaio, Elena; Song, Inho; Tao, Jun; Benfatto, Ivone

    2015-01-01

    Highlights: • The slow response reasons of the classic ITER Reactive Power Compensation (RPC) control are explained. • The dynamic behaviors of the ac/dc converter and of the RPC are characterized. • New control concept to speed up the RPC response is developed. • Good performance of the new RPC control is verified even during fast transient conditions. - Abstract: The ITER ac/dc conversion system can absorb a total active and reactive power up to 500 MW and 950 Mvar, respectively. The Reactive Power Compensation (RPC) system is rated for a nominal power of 750 Mvar necessary to comply with the allowable reactive power limit value from the grid of 200 Mvar. This system is currently under construction and is based on Static Var Compensation technology with Thyristor Controlled Reactor (TCR) and Tuned Filters. The RPC has to minimize the demand of reactive power from the grid; its control is based on a feed-forward method, where the corrective input is the measurement of the reactive power consumption of the ac/dc converters, derived from the 50 Hz component of the Fast Fourier Transform (FFT) of the three-phase voltages and currents. The delay introduced by the FFT calculation and the slow response of the TCR could make the response speed of the RPC not sufficient to face fast variations of the reactive power demand and therefore in this paper a new controller of the RPC able to overcome this shortcoming is proposed and evaluated. It is based on the calculation of the predicted consumption of the reactive power by using the voltage reference signals coming from the Plasma Control System and the measurements of the dc current of the ac/dc converters and of the 66 kV busbar voltage, and on the speed up of the RPC control by introducing a lead–lag transfer function.

  9. Improvement of the dynamic response of the ITER Reactive Power Compensation system

    Energy Technology Data Exchange (ETDEWEB)

    Finotti, Claudio, E-mail: claudio.finotti@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Gaio, Elena [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Song, Inho; Tao, Jun; Benfatto, Ivone [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2015-10-15

    Highlights: • The slow response reasons of the classic ITER Reactive Power Compensation (RPC) control are explained. • The dynamic behaviors of the ac/dc converter and of the RPC are characterized. • New control concept to speed up the RPC response is developed. • Good performance of the new RPC control is verified even during fast transient conditions. - Abstract: The ITER ac/dc conversion system can absorb a total active and reactive power up to 500 MW and 950 Mvar, respectively. The Reactive Power Compensation (RPC) system is rated for a nominal power of 750 Mvar necessary to comply with the allowable reactive power limit value from the grid of 200 Mvar. This system is currently under construction and is based on Static Var Compensation technology with Thyristor Controlled Reactor (TCR) and Tuned Filters. The RPC has to minimize the demand of reactive power from the grid; its control is based on a feed-forward method, where the corrective input is the measurement of the reactive power consumption of the ac/dc converters, derived from the 50 Hz component of the Fast Fourier Transform (FFT) of the three-phase voltages and currents. The delay introduced by the FFT calculation and the slow response of the TCR could make the response speed of the RPC not sufficient to face fast variations of the reactive power demand and therefore in this paper a new controller of the RPC able to overcome this shortcoming is proposed and evaluated. It is based on the calculation of the predicted consumption of the reactive power by using the voltage reference signals coming from the Plasma Control System and the measurements of the dc current of the ac/dc converters and of the 66 kV busbar voltage, and on the speed up of the RPC control by introducing a lead–lag transfer function.

  10. Biodiesel by catalytic reactive distillation powered by metal oxides

    NARCIS (Netherlands)

    Kiss, A.A.; Dimian, A.C.; Rothenberg, G.

    2008-01-01

    The properties and use of biodiesel as a renewable fuel as well as the problems associated with its current production processes are outlined. A novel sustainable esterification process based on catalytic reactive distillation is proposed. The pros and cons of manufacturing biodiesel via fatty acid

  11. A Hierarchical Control Scheme for Reactive Power and Harmonic Current Sharing in Islanded Microgrids

    DEFF Research Database (Denmark)

    Lorzadeh, Iman; Firoozabadi, Mehdi Savaghebi; Askarian Abyaneh, Hossein

    2015-01-01

    In this paper, a hierarchical control scheme consisting of primary and secondary levels is proposed for achieving accurate reactive power and harmonic currents sharing among interface inverters of distributed generators (DGs) in islanded microgrids. Firstly, fundamental and main harmonic componen...

  12. Estimation of reactive power sources dynamic limits for Volt / VAr control

    International Nuclear Information System (INIS)

    Orozco Alvarado, Juan Jose

    2013-01-01

    A generic model of capacity curves is obtained from the theoretical capacity curves of the distribution generators and reactive compensation elements. The obtained generic model is structured in a simplified method of points, taking eight strategic points of two detailed curves of a generator and through a series of interpolations, achieving the estimation of limits of capacity of delivery / consumption of the generator. The theory of electric generation elements and reactive power compensation is reviewed. The curves of capacity 'Reactive Power / Active Power' are achieved for different values of tension: from wind generators with complete converter and doubly fed, photovoltaic generators with inverter and synchronous generators. The 'Reactive Power / Line Tension' capacity curves are acquired from static var compensators (SVC). The generic limits of generators and SVC are estimated from the capacity curves [es

  13. Review of reactive power dispatch strategies for loss minimization in a DFIG-based wind farm

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2017-01-01

    power control strategies are investigated. All of the combined strategies are formulated based on the comprehensive loss models of WFs, including the loss models of DFIGs, converters, filters, transformers, and cables of the collection system. Optimization problems are solved by a Modified Particle......This paper reviews and compares the performance of reactive power dispatch strategies for the loss minimization of Doubly Fed Induction Generator (DFIG)-based Wind Farms (WFs). Twelve possible combinations of three WF level reactive power dispatch strategies and fourWind Turbine (WT) level reactive...... Swarm Optimization (MPSO) algorithm. The effectiveness of these strategies is evaluated by simulations on a carefully designed WF under a series of cases with different wind speeds and reactive power requirements of the WF. The wind speed at each WT inside the WF is calculated using the Jensen wake...

  14. Reactive power balance in a distribution network with wind farms and CHPS

    DEFF Research Database (Denmark)

    Lund, Torsten; Nielsen, John Eli; Hylle, Per

    2007-01-01

    In Denmark, a large part of the electricity is generated by wind turbines and combined heat and power plants. Most of them are connected to the distribution systems. In periods with high wind speeds, large flows of reactive power have been observed between the 150kV and the 60 kV systems. The tra......In Denmark, a large part of the electricity is generated by wind turbines and combined heat and power plants. Most of them are connected to the distribution systems. In periods with high wind speeds, large flows of reactive power have been observed between the 150kV and the 60 kV systems....... The transfer of reactive power reduces the capacity of the lines, causes thermal losses and can in some cases reduce the voltage stability margin of the system. To identify the origin of the problem, an actual distribution system with a high penetration of wind power and distributed generation has been...

  15. Local Reactive Power Control Methods for Overvoltage Prevention of Distributed Solar Inverters in Low-Voltage Grids

    DEFF Research Database (Denmark)

    Demirok, Erhan; Gonzalez, Pablo Casado; Frederiksen, Kenn H. B.

    2011-01-01

    on sensitivity analysis. The sensitivity analysis shows that the same amount of reactive power becomes more effective for grid voltage support if the solar inverter is located at the end of a feeder. Based on this fundamental knowledge, a location-dependent power factor set value can be assigned to each inverter......voltage (LV) grids by means of solar inverters with reactive power control capability. This paper underlines weak points of standard reactive power strategies which are already imposed by certain grid codes, and then, the study introduces a new reactive power control method that is based......, and the grid voltage support can be achieved with less total reactive power consumption. In order to prevent unnecessary reactive power absorption from the grid during admissible voltage range or to increase reactive power contribution from the inverters that are closest to the transformer during grid...

  16. 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)

  17. Consensus-based Distributed Control for Accurate Reactive, Harmonic and Imbalance Power Sharing in Microgrids

    DEFF Research Database (Denmark)

    Zhou, Jianguo; Kim, Sunghyok; Zhang, Huaguang

    2018-01-01

    This paper investigates the issue of accurate reactive, harmonic and imbalance power sharing in a microgrid. Harmonic and imbalance droop controllers are developed to proportionally share the harmonic power and the imbalance power among distributed generation (DG) units and improve the voltage...... voltage. With the proposed methods, the microgrid system reliability and flexibility can be enhanced and the knowledge of the line impedance is not required. And the reactive, harmonic and imbalance power can be proportionally shared among the DG units. Moreover, the quality of the voltage at PCC can...

  18. System and method for advanced power management

    Science.gov (United States)

    Atcitty, Stanley [Albuquerque, NM; Symons, Philip C [Surprise, AZ; Butler, Paul C [Albuquerque, NM; Corey, Garth P [Albuquerque, NM

    2009-07-28

    A power management system is provided that includes a power supply means comprising a plurality of power supply strings, a testing means operably connected to said plurality of power supply strings for evaluating performance characteristics of said plurality of power supply strings, and a control means for monitoring power requirements and comprising a switching means for controlling switching of said plurality of power supply strings to said testing means.

  19. Subcritical reactivity measurement at Angra 1 nuclear power plant

    International Nuclear Information System (INIS)

    Kuramoto, Renato Yoichi Ribeiro; Miranda, Anselmo Ferreira

    2011-01-01

    In order to speed up the Angra 1 NPP physics tests, this work intends to develop a digital reactivity meter combined with a methodology of the modified Neutron Source Multiplication (NSM) method with correction factors for subcriticality measurements at Angra 1 NPP. In the first part of this work, we have applied the Modified Neutron Source Multiplication (MNSM) Method with fundamental mode extraction, in order to improve the monitoring of the subcriticality at Angra 1 NPP during the criticality approach. In the second part, we developed a preliminary subcritical reactivity meter algorithm based on the point-reactor inverse kinetic model with six delayed neutron groups and external neutron source. The source strength was obtained through the Least Squares Inverse Kinetics Method (LSIKM). (author)

  20. Construction work management for nuclear power stations

    International Nuclear Information System (INIS)

    Yoshikawa, Yuichiro

    1982-01-01

    Nuclear power generation is positioned as the nucleus of petroleum substitution. In the Kansai Electric Power Co., efforts have been made constantly to operate its nuclear power plants in high stability and safety. At present, Kansai Electric Power Co. is constructing Units 3 and 4 in the Takahama Nuclear Power Station in Fukui Prefecture. Under the application of the management of construction works described here, both the nuclear power plants will start operation in 1985. The activities of Kansai Electric Power Co. in the area of this management are described: an outline of the construction works for nuclear power stations, the management of the construction works in nuclear power stations (the stages of design, manufacturing, installation and test operation, respectively), quality assurance activities for the construction works of nuclear power plants, important points in the construction work management (including the aspects of quality control). (J.P.N.)

  1. Simulation and study on reactivity disturbs dynamic character of HTR-10 nuclear power system

    International Nuclear Information System (INIS)

    Huang Xiaojin; Feng Yuankun

    2002-01-01

    In order to not only know 10 MW High Temperature Gas Cooled Reactor (HTR-10) nuclear power system's dynamic character more deeply but also to satisfy requirements of control system's design and analysis, the dynamic model of HTR-10 nuclear power system is established on the basis of dynamic model of HTR-10 nuclear system, which supplies turbine and generate electricity system model. Using this model, system's main variables' dynamic processes are simulated when control rod takes step reactivity disturb. The concussive progresses which is caused by reactivity disturb are analyzed. The results indicate that fuel temperature changing more slowly than nuclear power makes reactivity negative feedback not to restrain power changing, and then power concussive progress comes to being

  2. A Method of Dynamic Extended Reactive Power Optimization in Distribution Network Containing Photovoltaic-Storage System

    Science.gov (United States)

    Wang, Wu; Huang, Wei; Zhang, Yongjun

    2018-03-01

    The grid-integration of Photovoltaic-Storage System brings some undefined factors to the network. In order to make full use of the adjusting ability of Photovoltaic-Storage System (PSS), this paper puts forward a reactive power optimization model, which are used to construct the objective function based on power loss and the device adjusting cost, including energy storage adjusting cost. By using Cataclysmic Genetic Algorithm to solve this optimization problem, and comparing with other optimization method, the result proved that: the method of dynamic extended reactive power optimization this article puts forward, can enhance the effect of reactive power optimization, including reducing power loss and device adjusting cost, meanwhile, it gives consideration to the safety of voltage.

  3. ACCOUNTING OF REACTIVE POWER COMPENSATION LEVEL AT PAYMENT CALCULATION OF TECHNOLOGICAL CONSUMPTION (LOSSES OF ELECTRIC POWER FOR ITS TRANSMISSION IN POWER NETWORK

    Directory of Open Access Journals (Sweden)

    E. P. Zabello

    2005-01-01

    Full Text Available The method is proposed to make a correction in payment for consumption of reactive energy and power which is attributed to deviation of actual activation energy losses for reactive power compensation from their standard value. It is recommended to calculate standard loss values for every voltage level and actual loss values are to be determined with the help of application of remote electronic accounting means in the current mode of power consumption.

  4. Study for reactive power on distribution system line B RSG-GAS

    International Nuclear Information System (INIS)

    Yan Bony Marsahala

    2010-01-01

    Study for reactive power on distribution system line B RSG-GA is already done. The study intended to evaluate how much inductive load need the reactive power (positive), how much power factor, and what will be done to increase the power factor. The reactive power is the losses power, can't be changed into energy, but it is need for transmission process and it is cause the energy losses. The loads on distribution system line B consist of induction motors which are used for primary cooling system and secondary cooling system, lift, blower on cooling tower, and air condition system. Due to the motors using, the power factor are falling down to low. By the calculation results give that the inductive loads on distribution line B are 850 KVA and these loads caused the low power factor 0.80. If we want to increase the power factor up to 0.95, it is need to install the reactive loads likes capacitor bank 250 KVAR. (author)

  5. Towards a Reactive Power Oscillation Damping Controller for Wind Power Plant Based on Full Converter Wind Turbines

    DEFF Research Database (Denmark)

    Knüppel, Thyge; Kumar, Sathess; Thuring, Patrik

    2012-01-01

    In this paper a power oscillation damping controller (POD) based on modulation of reactive power (Q POD) is analyzed where the modular and distributed characteristics of the wind power plant (WPP) are considered. For a Q POD it is essential that the phase of the modulated output is tightly...... contributes to a collective response. This ability is shown with a 150 wind turbine (WT) WPP with all WTs represented, and it is demonstrated that the WPP contributes to the inter-area damping. The work is based on a nonlinear, dynamic model of the 3.6 MW Siemens Wind Power WT....... controlled to achieve a positive damping contribution. It is investigated how a park level voltage, reactive power, and power factor control at different grid strengths interact with the Q POD in terms of a resulting phase shift. A WPP is modular and distributed and a WPP Q POD necessitate that each WT...

  6. THE IMPACT OF POWER COEFFICIENT OF REACTIVITY ON CANDU 6 REACTORS

    Directory of Open Access Journals (Sweden)

    D. KASTANYA

    2013-10-01

    Full Text Available The combined effects of reactivity coefficients, along with other core nuclear characteristics, determine reactor core behavior in normal operation and accident conditions. The Power Coefficient of Reactivity (PCR is an aggregate indicator representing the change in reactor core reactivity per unit change in reactor power. It is an integral quantity which captures the contributions of the fuel temperature, coolant void, and coolant temperature reactivity feedbacks. All nuclear reactor designs provide a balance between their inherent nuclear characteristics and the engineered reactivity control features, to ensure that changes in reactivity under all operating conditions are maintained within a safe range. The CANDU® reactor design takes advantage of its inherent nuclear characteristics, namely a small magnitude of reactivity coefficients, minimal excess reactivity, and very long prompt neutron lifetime, to mitigate the demand on the engineered systems for controlling reactivity and responding to accidents. In particular, CANDU reactors have always taken advantage of the small value of the PCR associated with their design characteristics, such that the overall design and safety characteristics of the reactor are not sensitive to the value of the PCR. For other reactor design concepts a PCR which is both large and negative is an important aspect in the design of their engineered systems for controlling reactivity. It will be demonstrated that during Loss of Regulation Control (LORC and Large Break Loss of Coolant Accident (LBLOCA events, the impact of variations in power coefficient, including a hypothesized larger than estimated PCR, has no safety-significance for CANDU reactor design. Since the CANDU 6 PCR is small, variations in the range of values for PCR on the performance or safety of the reactor are not significant.

  7. Nuclear power plant life management

    International Nuclear Information System (INIS)

    Rorive, P.; Berthe, J.; Lafaille, J.P.; Eussen, G.

    1998-01-01

    Several definitions can be given to the design life of a nuclear power plant just as they can be attributed to the design life of an industrial installation: the book-keeping life which is the duration of the provision for depreciation of the plant, the licensed life which corresponds to the duration for which the plant license has been granted and beyond which a new license should be granted by the safety authorities, the design life which corresponds to the duration specified for ageing and fatigue calculations in the design of some selected components during the plant design phase, the technical life which is the duration of effective technical operation and finally the economic life corresponding to the duration of profitable operation of the plant compared with other means of electricity production. Plant life management refers to the measures taken to cope with the combination of licensed, design, technical and economical life. They can include repairs and replacements of components which have arrived to the end of their life due to known degradation processes such as fatigue, embrittlement, corrosion, wear, erosion, thermal ageing. In all cases however, it is of great importance to plan the intervention so as to minimise the economic impact. Predictive maintenance is used together with in-service inspection programs to fulfil this goal. The paper will go over the methodologies adopted in Belgium in all aspects of electrical, mechanical and civil equipment for managing plant life. (author)

  8. The effect of reactive emotions expressed in response to another's anger on inferences of social power.

    Science.gov (United States)

    Hareli, Shlomo; David, Shlomo

    2017-06-01

    Social perception of emotions is influenced by the context in which it occurs. One such context is a social interaction involving an exchange of emotions. The way parties to the interaction are perceived is shaped by the combination of emotions exchanged. This idea was examined by assessing the extent to which expressions of anger toward a target-which, in isolation, are perceived as signals of high social power-are influenced by the target's emotional reaction to it (i.e., reactive emotions). Three studies show that the angry person was perceived as having a higher level of social power when this anger was responded by fear or sadness than when it was responded by neutrality or anger. Study 1 indicated that reactive emotions have a stronger effect on perceived social power when emotions were incongruent with gender stereotypes. Study 2 indicated that these effects are a result of these emotions serving as reactive emotions rather than a benchmark against which the angry person's power is assessed. Study 3 showed that reactive emotions affect perceived social power by serving as signals of the level to which the high social power suggested by the first person's expression is confirmed by its target. Comparing effects of reactive emotions to anger with reactive emotions to sadness, showed that perceived social power of the expresser is determined by the nature of the expression, with some adjustment caused by the reactive emotions. This underscores the importance of social interaction as a context for the social perception of emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  9. Reactive power compensation. System service - line quality. 2. ed.; Blindleistungskompensation. Systemdienstleistung - Netzqualitaet

    Energy Technology Data Exchange (ETDEWEB)

    Grosse-Gehling, Martin; Just, Wolfgang; Reese, Juergen; Schlabbach, Juergen

    2013-11-01

    Reactive power compensation is playing an increasingly important role as the need for an efficient use of operating equipment and power grids continues to grow. This book presents the fundamentals of reactive power compensation in low and medium voltage grids, offering a wealth of application and calculation examples that will further the reader's understanding of the following topics: 1. design, dimensioning and operation of capacitors and capacitor installations; 2. long-term stability and ageing of capacitor installations; 3. use of passive and active filters; 4. improvement of voltage quality by means of filters and capacitor installations; 5. provision of reactive power compensation by means of power electronics; 6. costs and economic efficiency of reactive power compensation and filter equipment; 7. considerations from the viewpoint of the power supply industry; price regulations; 8. information requirements concerning PCB-containing capacitors; 9. climate protection and energy efficiency through reactive power compensation; 10. technical connection requirements and guidelines; 11. special technical issues concerning the use of reactive power compensation installations. [German] Die Blindleistungskompensation gewinnt angesichts der Notwendigkeit zur erhoehten Ausnutzung der Betriebsmittel und Netze zunehmend an Bedeutung. In diesem Buch werden die Grundlagen der Blindleistungskompensation in Nieder- und Mittelspannungsnetzen beschrieben und folgende Themen anhand zahlreicher Anwendungs- und Berechnungsbeispiele vertieft: 1. Aufbau, Auslegung und Betrieb von Kondensatoren und Kondensatoranlagen, 2. Langzeitstabilitaet und Alterung von Kondensatoranlagen, 3. Einsatz passiver und aktiver Filter, 4. Verbesserung der Spannungsqualitaet durch Filter und Kondensatoranlagen, 5. Blindleistungsbereitstellung mit Leistungselektronik, 6. Kosten und Wirtschaftlichkeit von Kompensations- und Filteranlagen, 7. Elektrizitaetswirtschaftliche Betrachtungen

  10. Distribution factors for reactive power in the presence of bilateral transactions

    International Nuclear Information System (INIS)

    De Tuglie, E.; Torelli, F.

    2004-01-01

    The twin factors of limited investment in electric transmission systems and the overexploitation of electrical resources results in an increase in the need for reactive power to support system voltage profile and to supply loads. It is reasonable to expect that generators and compensators, heavily involved in reactive support on a voluntary basis, will be remunerated for their service by market transactions. This remuneration will depend on the network topology, i.e. of buyers, sellers and reactive injection locations, on the active power exchanged and the reactive power required by loads. All these aspects are taken into account in developing a methodology based on circuit considerations. Using this approach, at a given system operating point characterised by a predefined set of transactions, reactive responsibilities can be formulated as the sum of two terms: one strictly related to transactions and the other dependent on electric network parameters. Test results demonstrate the efficacy of the proposed methodology in sharing reactive power responsibilities in a fair way among market participants. (author)

  11. Reactive power and voltage control strategy based on dynamic and adaptive segment for DG inverter

    Science.gov (United States)

    Zhai, Jianwei; Lin, Xiaoming; Zhang, Yongjun

    2018-03-01

    The inverter of distributed generation (DG) can support reactive power to help solve the problem of out-of-limit voltage in active distribution network (ADN). Therefore, a reactive voltage control strategy based on dynamic and adaptive segment for DG inverter is put forward to actively control voltage in this paper. The proposed strategy adjusts the segmented voltage threshold of Q(U) droop curve dynamically and adaptively according to the voltage of grid-connected point and the power direction of adjacent downstream line. And then the reactive power reference of DG inverter can be got through modified Q(U) control strategy. The reactive power of inverter is controlled to trace the reference value. The proposed control strategy can not only control the local voltage of grid-connected point but also help to maintain voltage within qualified range considering the terminal voltage of distribution feeder and the reactive support for adjacent downstream DG. The scheme using the proposed strategy is compared with the scheme without the reactive support of DG inverter and the scheme using the Q(U) control strategy with constant segmented voltage threshold. The simulation results suggest that the proposed method has a significant improvement on solving the problem of out-of-limit voltage, restraining voltage variation and improving voltage quality.

  12. 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)

  13. Calculation methods of reactivity using derivatives of nuclear power and Filter fir

    International Nuclear Information System (INIS)

    Diaz, Daniel Suescun

    2007-01-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  14. Environmental management in the National Power Corporation

    International Nuclear Information System (INIS)

    Petel, M.R.L.

    1996-01-01

    Environmental management in the National Power Corporation (NPC) is enshrined in the corporate charter. Environmental management practice can be traced back to the past purely hydroelectric power generation days, of the corporation. One good thing about nuclear power plant project of NPC, is that it required a formalization and documentation of environmental management, as part of the licensing procedure for the project. Thereafter, environmental management had been strengthened and institutionalized in the corporation. Succeeding years had also witnessed the escalation of the development and diversification of electricity generation sources, including the development of geothermal power, and to a small extent yet, renewable energy, such as wind power. The corporation has also intensified the installation of transmission lines of varying sizes in various locations and has gone, for now, for its internal needs, into telecommunications. With the anticipated further developments in the power sector, i.e., the ever increasing demand for power and the privitization of the power industry, new challenges loom in environmental management for the sector. The parallel developments in the environmental sciences and the collective experiences in power generation and environmental management, locally and abroad, will be very handy in meeting the challenges. The increasing stringency of environmental regulations and standards are also providing continuing challenges to all power utilities like NPC. Globally, the power scenario points towards challenging environmental management requirements, in view of the increasing complexity and gravity of environmental problems facing nations. NPC will still be a player in this scenario and therefore, will need to respond accordingly. (author)

  15. Risk management in nuclear power social aspects

    International Nuclear Information System (INIS)

    Sappa, N.N.

    1996-01-01

    Problems connected with safety evaluation and risk management during operation of nuclear power installations are considered. Social aspects of risk assessment of enterprises with increased danger are discussed

  16. Active and reactive power neurocontroller for grid-connected photovoltaic generation system

    Directory of Open Access Journals (Sweden)

    I. Abadlia

    2016-03-01

    Full Text Available Many researchers have contributed to the development of a firm foundation for analysis and design of control applications in grid-connected renewable energy sources. This paper presents an intelligent control algorithm fond on artificial neural networks for active and reactive power controller in grid-connected photovoltaic generation system. The system is devices into two parts in which each part contains an inverter with control algorithm. A DC/DC converter in output voltage established by control magnitude besides maximum power point tracker algorithm always finds optimal power of the PV array in use. A DC/AC hysteresis inverter designed can synchronize a sinusoidal current output with the grid voltage and accurate an independent active and reactive power control. Simulation results confirm the validation of the purpose. Neurocontroller based active and reactive power presents an efficiency control that guarantees good response to the steps changing in active and reactive power with an acceptable current/voltage synchronism. In this paper the power circuit and the control system of the presented grid-connected photovoltaic generation system is simulated and tested by MatLab/Simulink.

  17. Reactive power interconnection requirements for PV and wind plants : recommendations to NERC.

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, Jason (General Electric, Schenectady, NY); Walling, Reigh (General Electric, Schenectady, NY); Peter, William (SunPower, Richmond, CA); Von Engeln, Edi (NV Energy, Reno, NV); Seymour, Eric (AEI, Fort Collins, CO); Nelson, Robert (Siemens Wind Turbines, Orlando, FL); Casey, Leo (Satcon, Boston, MA); Ellis, Abraham; Barker, Chris. (SunPower, Richmond, CA)

    2012-02-01

    Voltage on the North American bulk system is normally regulated by synchronous generators, which typically are provided with voltage schedules by transmission system operators. In the past, variable generation plants were considered very small relative to conventional generating units, and were characteristically either induction generator (wind) or line-commutated inverters (photovoltaic) that have no inherent voltage regulation capability. However, the growing level of penetration of non-traditional renewable generation - especially wind and solar - has led to the need for renewable generation to contribute more significantly to power system voltage control and reactive power capacity. Modern wind-turbine generators, and increasingly PV inverters as well, have considerable dynamic reactive power capability, which can be further enhanced with other reactive support equipment at the plant level to meet interconnection requirements. This report contains a set of recommendations to the North-America Electricity Reliability Corporation (NERC) as part of Task 1-3 (interconnection requirements) of the Integration of Variable Generation Task Force (IVGTF) work plan. The report discusses reactive capability of different generator technologies, reviews existing reactive power standards, and provides specific recommendations to improve existing interconnection standards.

  18. MILP Approach for Bilevel Transmission and Reactive Power Planning Considering Wind Curtailment

    DEFF Research Database (Denmark)

    Ugranli, Faruk; Karatepe, Engin; Nielsen, Arne Hejde

    2017-01-01

    In this study, two important planning problems in power systems that are transmission expansion and reactive power are formulated as a mixed-integer linear programming taking into account the bilevel structure due to the consideration of market clearing under several load-wind scenarios....... The objective of the proposed method is to minimize the installation cost of transmission lines, reactive power sources, and the annual operation costs of conventional generators corresponding to the curtailed wind energy while maintaining the reliable system operation. Lower level problems of the bilevel...... structure are designated for the market clearing which is formulated by using the linearized optimal power flow equations. In order to obtain mixed-integer linear programming formulation, the so-called lower level problems are represented by using primal-dual formulation. By using the proposed method, power...

  19. Optimal Coordinated EV Charging with Reactive Power Support in Constrained Distribution Grids

    Energy Technology Data Exchange (ETDEWEB)

    Paudyal, Sumit; Ceylan, Oğuzhan; Bhattarai, Bishnu P.; Myers, Kurt S.

    2017-07-01

    Electric vehicle (EV) charging/discharging can take place in any P-Q quadrants, which means EVs could support reactive power to the grid while charging the battery. In controlled charging schemes, distribution system operator (DSO) coordinates with the charging of EV fleets to ensure grid’s operating constraints are not violated. In fact, this refers to DSO setting upper bounds on power limits for EV charging. In this work, we demonstrate that if EVs inject reactive power into the grid while charging, DSO could issue higher upper bounds on the active power limits for the EVs for the same set of grid constraints. We demonstrate the concept in an 33-node test feeder with 1,500 EVs. Case studies show that in constrained distribution grids in coordinated charging, average costs of EV charging could be reduced if the charging takes place in the fourth P-Q quadrant compared to charging with unity power factor.

  20. Power management of a wind energy conversion system equipped by DFIG

    Directory of Open Access Journals (Sweden)

    Iman Zangiabadi

    2016-06-01

    Full Text Available Today wind is one of the attractive points of energy area which has got the noticeable amount of investment and studies in this field. Considering the importance of the wind energy and its potentials as one of the renewable energy sources, in this paper managing the production of active and reactive powers of a wind energy conversion system equipped with DFIG has been studied. In this regard, a structure based on vector control is offered to achieve an independent control of active and reactive powers. The strategy of managing the production of active and reactive power is applied to network by rotor side converter of a DFIG. The production of active power according to the maximum power point taking (MPPT strategy to get a maximum power of the wind energy has been done and also improvement of power quality based on strategies of power factor correction and harmonics reduction have been arranged for a power network. In order to evaluate the performance of the proposed method, a DFIG connected with a power network in different conditions of the reactive load has been simulated by MATLAB software.Obviously, the results state the proper operation of the power control of wind energy converting system , improvement of the network power factor, and Reduction of harmonic current of network based on the proposed method.

  1. Haiyang nuclear power construction management and practice

    International Nuclear Information System (INIS)

    Wang Fengxue

    2010-01-01

    The paper introduces the basic situation of Shandong Haiyang Nuclear Power Plant, as well as the management and progress of the project. Through the construction management practice, problems encountered in nuclear power construction are put forward for peer exchange and discussion. (author)

  2. Nuclear power project management information system

    International Nuclear Information System (INIS)

    Zou Lailong; Zhang Peng; Xiao Ziyan; Chun Zengjun; Huang Futong

    2001-01-01

    Project Management Information System is an important infrastructure facility for the construction and operation of Nuclear Power Station. Based on the practice of Lingao nuclear power project management information system (NPMIS), the author describes the NPMIS design goals, system architecture and software functionality, points out the outline issues during the development and deployment of NPMIS

  3. On-chip power delivery and management

    CERN Document Server

    Vaisband, Inna P; Popovich, Mikhail; Mezhiba, Andrey V; Köse, Selçuk; Friedman, Eby G

    2016-01-01

    This book describes methods for distributing power in high speed, high complexity integrated circuits with power levels exceeding many tens of watts and power supplies below a volt. It provides a broad and cohesive treatment of power delivery and management systems and related design problems, including both circuit network models and design techniques for on-chip decoupling capacitors, providing insight and intuition into the behavior and design of on-chip power distribution systems. Organized into subareas to provide a more intuitive flow to the reader, this fourth edition adds more than a hundred pages of new content, including inductance models for interdigitated structures, design strategies for multi-layer power grids, advanced methods for efficient power grid design and analysis, and methodologies for simultaneously placing on-chip multiple power supplies and decoupling capacitors. The emphasis of this additional material is on managing the complexity of on-chip power distribution networks.

  4. Change in CANDU-6 reactivity following a power reduction at low PHT purity

    International Nuclear Information System (INIS)

    Whitlock, J.J.; Soulard, M.R.; Baudouin, A.

    1995-01-01

    The reactivity effect of a power reduction in CANDU-6 is examined using a three-dimensional, steady-state, coupled neutronics/thermalhydraulics methodology, starting from a global irradiation distribution matched to site data. The power reduction is sufficient to suppress coolant boiling in the fuel channels, and thus the significant parameters affecting reactivity are an increase in coolant density and a decrease in fuel temperature. These individual components are estimated using infinite-lattice-cell methodology. The effect of using newer methodology, particularly for the thermalhydraulic analysis, is examined by comparison with previous simulations. (author). 10 refs., 7 tabs., 1 fig

  5. A Hierarchical Modeling for Reactive Power Optimization With Joint Transmission and Distribution Networks by Curve Fitting

    DEFF Research Database (Denmark)

    Ding, Tao; Li, Cheng; Huang, Can

    2018-01-01

    –slave structure and improves traditional centralized modeling methods by alleviating the big data problem in a control center. Specifically, the transmission-distribution-network coordination issue of the hierarchical modeling method is investigated. First, a curve-fitting approach is developed to provide a cost......In order to solve the reactive power optimization with joint transmission and distribution networks, a hierarchical modeling method is proposed in this paper. It allows the reactive power optimization of transmission and distribution networks to be performed separately, leading to a master...... optimality. Numerical results on two test systems verify the effectiveness of the proposed hierarchical modeling and curve-fitting methods....

  6. 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).

  7. Nuclear power. Volume 2. Nuclear power project management

    International Nuclear Information System (INIS)

    Pedersen, E.S.

    1978-01-01

    NUCLEAR POWER PLANT DESIGN is intended to be used as a working reference book for management, engineers and designers, and as a graduate-level text for engineering students. The book is designed to combine theory with practical nuclear power engineering and design experience, and to give the reader an up-to-date view of the status of nuclear power and a basic understanding of how nuclear power plants function. Volume 2 contains the following chapters: (1) review of nuclear power plants; (2) licensing procedures; (3) safety analysis; (4) project professional services; (5) quality assurance and project organization; (6) construction, scheduling, and operation; (7) nuclear fuel handling and fuel management; (8) plant cost management; and (9) conclusion

  8. Specification of data centre power management strategies

    NARCIS (Netherlands)

    Postema, Björn F.; Haverkort, Boudewijn R.

    2017-01-01

    In recent work, we proposed a flexible simulation framework (using AnyLogic) for the trade-off. analysis of power and performance in data centres. We now extend this framework with a versatile module to study the effect of advanced power management strategies based on both power and performance

  9. Neutron and thermo - hydraulic model of a reactivity transient in a nuclear power plant fuel element

    International Nuclear Information System (INIS)

    Oliva, Jose de Jesus Rivero

    2012-01-01

    A reactivity transient without reactor scram was modeled and calculated using analytical expressions for the space distributions of the temperature fields, combined with discrete numerical calculations for the time dependences of thermal power and temperatures. The transient analysis covered the time dependencies of reactivity, global thermal power, fuel heat flux and temperatures in fuel, cladding and cooling water. The model was implemented in Microsoft Office Excel, dividing the Excel file in several separated worksheets for input data, initial steady-state calculations, calculation of parameters non-depending on eigenvalues, eigenvalues determination, calculation of parameters depending on eigenvalues, transient calculation and graphical representation of intermediate and final results. The results show how the thermal power reaches a new equilibrium state due to the negative reactivity feedback derived from the fuel temperature increment. Nevertheless, the reactor mean power increases 40% during the first second and, in the hottest channel, the maximum fuel temperature goes to a significantly high value, slightly above 2100 deg C, after 8 seconds of transient. Consequently, the results confirm that certain degree of fuel damage could be expected in case of a reactor scram failure. Once the basic model has being established the scope of accidents for future analyses can be extended, modifying the nuclear power behavior (reactivity) during transient and the boundary conditions for coolant temperature. A more complex model is underway for an annular fuel element. (author)

  10. Single-Phase Boost Inverter-Based Electric Vehicle Charger With Integrated Vehicle to Grid Reactive Power Compensation

    DEFF Research Database (Denmark)

    Wickramasinghe Abeywardana, Damith Buddika; Acuna, Pablo; Hredzak, Branislav

    2018-01-01

    Vehicle to grid (V2G) reactive power compensation using electric vehicle (EV) onboard chargers helps to ensure grid power quality by achieving unity power factor operation. However, the use of EVs for V2G reactive power compensation increases the second-order harmonic ripple current component...... from the grid, exposes the EV battery to these undesirable ripple current components for a longer period and discharges the battery due to power conversion losses. This paper presents a way to provide V2G reactive power compensation through a boost inverter-based single stage EV charger and a DC...

  11. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System with Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators and it is able to support certain amount of the reactive power. For a typical doubly-fed induction generator wind turbine system, the reactive power can be supported either through...... for the generator and the wind power converter in terms of the reactive power done by the rotor-side converter or the grid-side converter with various grid filters. Afterwards, the annual energy loss is also estimated based on yearly wind profile. Finally, experimental results of the loss distribution are performed...... the rotor-side converter or the grid-side converter. This paper firstly compares the current ripples and supportive reactive power ranges between the conventional L and optimized LCL filter, if the reactive power is injected from the grid-side converter. Then, the loss distribution is evaluated both...

  12. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System With Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2015-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators, and it is able to support certain amount of the reactive power. For a typical doubly fed induction generator (DFIG) wind turbine system, the reactive power can be supported either...... for the generator and the wind power converter in terms of the reactive power done by the rotor-side converter or the grid-side converter with various grid filters. Afterward, the annual energy loss is also estimated based on yearly wind profile. Finally, experimental results of the loss distribution are performed...... through the rotor-side converter or the grid-side converter. This paper first compares the current ripples and supportive reactive power ranges between the conventional L and optimized LCL filter, if the reactive power is injected from the grid-side converter. Then, the loss distribution is evaluated both...

  13. Measures to improve nuclear power project management

    International Nuclear Information System (INIS)

    Ma Xinchao

    2012-01-01

    Focusing on correct application of ability level principle in setting organizational structure, the effective management system has been established, and 8 practical management regimes have been developed. Personnel training and management work shall be well done and enhanced. Experience feedback in construction management shall be well done for all systems. Exchange of construction and management techniques shall be actively carried out. All staff shall participate in safety management. KPI system is adopted for assessing stakeholders' project management method, and PDCA cycle is adopted for continued improved. Management level upgrading measures are proposed to ensure the smooth construction of nuclear power project. Setting forth and popularizing management theory can provide reference for and promote the smooth progress of various nuclear power projects. (author)

  14. Management of Excess Reactive Nitrogen in the Environment

    Science.gov (United States)

    Galloway, J. N.; Theis, T.; Doering, O.

    2011-12-01

    Managing the impacts of excessive reactive nitrogen (Nr) in the environment is a complex problem that begins with the recognition of the obligate dietary need for Nr by all living populations. The human solution to this need has been to devise ways to bring Nr into the biosphere (via the Haber-Bosch process) to grow food. Other Nr is created as a by-product of fossil-fuel combustion. The net result is the introduction of more than five times the Nr created by natural processes in the U.S., only a fraction of which is converted back to diatomic nitrogen through denitrification. This presentation summarizes findings and recommendations of the newly-released US EPA Science Advisory Board's Integrated Nitrogen Committee report, "Reactive Nitrogen in the United States: An Analysis of Flows, Consequences, and Management Options", that deal specifically with approaches for solving the excess Nr problem. These can be grouped into four general areas: (1) Recognition of the Problem. Until there is recognition that excess Nr is a serious problem with economic, health, and societal consequences, there will be little willingness to expend resources on this issue. Education, communication and outreach are critically important to engender in regulators, and the public at large, sufficient will to undertake the large scale effort needed to reduce Nr in the environment. (2) Development of Integrated Regulatory Approaches. Given what is known about the way Nr behaves, efforts to deal with excess Nr must be organized in a way that reflects the nature of the problem. Unfortunately, most approaches tend to conceive of Nr issues within a narrowly focused disciplinary model, and our policy and regulatory institutions are often bound by enabling legislation that stresses source-by-source, chemical-by-chemical, and media-by-media. The resulting regulatory structure that has evolved for problems such as Nr that affect human health and the environment is apt to miss the complex nature of the

  15. Nuclear power. Volume 2: nuclear power project management

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The following topics are discussed: review of nuclear power plants; licensing procedures; safety analysis; project professional services; quality assurance and project organization; construction, scheduling and operation; construction, scheduling and operation; nuclear fuel handling and fuel management; and plant cost management. 116 references, 115 figures, 33 tables

  16. Settlement of reactive power compensation in the light of white certificates

    Directory of Open Access Journals (Sweden)

    Zajkowski Konrad

    2017-01-01

    The detailed method and an estimation method proposed for the determination of savings on active energy as a result of the reactive power compensation carried out possess some errors and inconvenience. The detailed method requires knowledge of the network topology and a determination of reactive power Q at each point of the network. The estimation method of analysis is easy in execution, especially if the consumer of energy is the main or the most significant purchaser of electricity in the network. Unfortunately, this latter method can be used only for activities that do not require high computational accuracy. The results obtained by this method are approximate values that can be used for the calculation of economic indicators. The estimation method is suitable for determining the number of white certificates when a power audit concerns a recipient of electricity, the structure of which is a large number of divisions scattered at many different locations in the power system.

  17. Design and Optimisation of a Simple Filter Group for Reactive Power Distribution

    Directory of Open Access Journals (Sweden)

    Ryszard Klempka

    2016-01-01

    Full Text Available Basic methods are presented to design a simple filter group and a method of shaping the resultant of the filter group’s impedance characteristics (distribution of the characteristics’ extremes and then project equations were transformed into a uniform, common form that addresses issues of the reactive power distribution between component filters. The analysis also takes into account the filters’ detuning from the reduced harmonics and quality factors of passive elements. Another important factor of the analysis considered was the power grid equivalent impedance affecting the filtration effectiveness. A criterion for the filter group’s filtration effectiveness evaluation was proposed and optimisation was completed for the reactive power distribution between separate filters in the function of the power grid’s equivalent inductance.

  18. Opposition-Based Improved PSO for Optimal Reactive Power Dispatch and Voltage Control

    Directory of Open Access Journals (Sweden)

    Shengrang Cao

    2015-01-01

    Full Text Available An opposition-based improved particle swarm optimization algorithm (OIPSO is presented for solving multiobjective reactive power optimization problem. OIPSO uses the opposition learning to improve search efficiency, adopts inertia weight factors to balance global and local exploration, and takes crossover and mutation and neighborhood model strategy to enhance population diversity. Then, a new multiobjective model is built, which includes system network loss, voltage dissatisfaction, and switching operation. Based on the market cost prices, objective functions are converted to least-cost model. In modeling process, switching operation cost is described according to the life cycle cost of transformer, and voltage dissatisfaction penalty is developed considering different voltage quality requirements of customers. The experiment is done on the new mathematical model. Through the simulation of IEEE 30-, 118-bus power systems, the results prove that OIPSO is more efficient to solve reactive power optimization problems and the model is more accurate to reflect the real power system operation.

  19. Use of reactivity constraints for the automatic control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.; Lanning, D.D.; Ray, A.

    1985-01-01

    A theoretical framework for the automatic control of reactor power has been developed and experimentally evaluated on the 5 MWt Research Reactor that is operated by the Massachusetts Institute of Technology. The controller functions by restricting the net reactivity so that it is always possible to make the reactor period infinite at the desired termination point of a transient by reversing the direction of motion of whatever control mechanism is associated with the controller. This capability is formally designated as ''feasibility of control''. It has been shown experimentally that maintenance of feasibility of control is a sufficient condition for the automatic control of reactor power. This research should be of value in the design of closed-loop controllers, in the creation of reactivity displays, in the provision of guidance to operators regarding the timing of reactivity changes, and as an experimental envelope within which alternate control strategies can be evaluated

  20. Economic analysis of reactive power compensation in a wind farm: Influence of Spanish energy policy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E.; Daroca, F. [Grupo Eolicas Riojanas, Carretera de Laguardia, 91-93, 26006 Logrono, La Rioja (Spain); Sanz, F.; Blanco, J. [Department of Mechanical Engineering, University of La Rioja, Logrono, La Rioja (Spain); Jimenez, E. [Department of Electrical Engineering, University of La Rioja, Logrono, La Rioja (Spain)

    2008-08-15

    Presently, renewable energies and especially wind energy are gaining a special relevance in the electrical market worldwide. This current rate of growth brings with it the need for the various wind farms to not limit themselves to producing energy but also provide stability to the network within its capabilities. So, the actual objective is to adapt the installations that produce wind energy in such a way that they give a maximum amount of support in any given moment to the electrical network. For this purpose, there are governing techno-economic parameters that influence the economic behavior of commercial wind farms. A complete cost-benefit analysis model is developed, focused on incorporating automatic capacitor banks into wind farms for the compensation of reactive power. This economic analysis is about doubly fed induction generator (DFIG) wind turbines. Although this kind of wind turbines have a certain capability in terms of modulating reactive power, this capacity is not enough to achieve the new requirements of reactive power regulation in Spain and it is necessary to invest in systems of external compensation. In this paper, we have studied the case of DFIG wind turbine and capacitor banks, although the used methodology can be applied to other technologies as well by simply amplifying the algorithms according to the specific characteristics of the option elected. Following this premise, a detailed analysis of the specific needs of a wind farm has been carried out, as well as a search for the optimum performance for the compensation of reactive power. (author)

  1. Loss Minimizing Operation of Doubly Fed Induction Generator Based Wind Generation Systems Considering Reactive Power Provision

    DEFF Research Database (Denmark)

    Baohua, Zhang; Hu, Weihao; Chen, Zhe

    2014-01-01

    The paper deals with control techniques for minimizing the operating loss of doubly fed induction generator based wind generation systems when providing reactive power. The proposed method achieves its goal through controlling the rotor side q-axis current in the synchronous reference frame...

  2. Economic analysis of reactive power compensation in a wind farm: Influence of Spanish energy policy

    International Nuclear Information System (INIS)

    Martinez, E.; Daroca, F.; Sanz, F.; Blanco, J.; Jimenez, E.

    2008-01-01

    Presently, renewable energies and especially wind energy are gaining a special relevance in the electrical market worldwide. This current rate of growth brings with it the need for the various wind farms to not limit themselves to producing energy but also provide stability to the network within its capabilities. So, the actual objective is to adapt the installations that produce wind energy in such a way that they give a maximum amount of support in any given moment to the electrical network. For this purpose, there are governing techno-economic parameters that influence the economic behavior of commercial wind farms. A complete cost-benefit analysis model is developed, focused on incorporating automatic capacitor banks into wind farms for the compensation of reactive power. This economic analysis is about doubly fed induction generator (DFIG) wind turbines. Although this kind of wind turbines have a certain capability in terms of modulating reactive power, this capacity is not enough to achieve the new requirements of reactive power regulation in Spain and it is necessary to invest in systems of external compensation. In this paper, we have studied the case of DFIG wind turbine and capacitor banks, although the used methodology can be applied to other technologies as well by simply amplifying the algorithms according to the specific characteristics of the option elected. Following this premise, a detailed analysis of the specific needs of a wind farm has been carried out, as well as a search for the optimum performance for the compensation of reactive power. (author)

  3. Reactive Power Control for Improving Wind Turbine System Behavior Under Grid Faults

    DEFF Research Database (Denmark)

    Rodriguez, P.; Timbus, A.; Teodorescu, Remus

    2009-01-01

    This letter aims to present a generalized vector-based formulation for calculating the grid-side current reference to control reactive power delivered to the grid. Strategies for current reference generation were implemented on the abc stationary reference frame, and their effectivenesswas...... demonstrated experimentally, perhaps validating the theoretical analysis even under grid fault conditions....

  4. 77 FR 21555 - Reactive Power Resources; Supplemental Notice of Technical Conference

    Science.gov (United States)

    2012-04-10

    .... This panel will discuss: Methods used to determine the reactive power requirements for a transmission... Jenkins, Director--Utility Interconnection, First Solar Kris Zadlo, Vice President, Invenergy Richard..., Director--Utility Interconnection, First Solar Michael Jacobs, Director Market and Regulatory Policy...

  5. Settlement of reactive power compensation in the light of white certificates

    Science.gov (United States)

    Zajkowski, Konrad

    2017-10-01

    The article discusses the problem of the determination of savings on active energy as a result of a reactive power compensation. Statutory guidance on the required energy audit to obtain white certificates in the European Union was followed. The analysis was made on the basis of the Polish Law. The paper presents a detailed analytical method and an estimation method taking into account the impact on the line, the transformer and the generator. According to the relevant guidelines in the European Union, the reduction of CO2 emissions by calculating the saving of active power should be determined. The detailed method and an estimation method proposed for the determination of savings on active energy as a result of the reactive power compensation carried out possess some errors and inconvenience. The detailed method requires knowledge of the network topology and a determination of reactive power Q at each point of the network. The estimation method of analysis is easy in execution, especially if the consumer of energy is the main or the most significant purchaser of electricity in the network. Unfortunately, this latter method can be used only for activities that do not require high computational accuracy. The results obtained by this method are approximate values that can be used for the calculation of economic indicators. The estimation method is suitable for determining the number of white certificates when a power audit concerns a recipient of electricity, the structure of which is a large number of divisions scattered at many different locations in the power system.

  6. Power Management for Energy Systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel

    In this thesis, we consider the control of two different industrial applications that belong at either end of the electricity grid; a power consumer in the form of a commercial refrigeration system, and wind turbines for power production. Our primary studies deal with economic model predictive...... penetration of renewable, fossil-free energy sources such as solar and wind power. To facilitate such intermittent power producers, we must not only control the production of electricity, but also the consumption, in an ecient and exible manner. By enabling the use of thermal energy storage in supermarkets...... of temperature dependent efficiencies in the refrigeration cycle. -Nonlinear economic MPC with uncertain predictions and the implementation of very simple predictors that use entirely historical data of, e.g., electricity prices and outdoor temperatures. Economic MPC for wind turbines, including -Optimal steady...

  7. Smart Shipboard Power System Operation and Management

    DEFF Research Database (Denmark)

    Kanellos, Fotis D.; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

    2016-01-01

    as all-electric ships (AESs), the need for more cost-effective and emission-aware solutions is augmented. Such onboard systems are prone to sudden load variations due to the changing weather conditions as well as mission profile, thus they require effective power management systems (PMSs) to operate...... optimally under different working conditions. In this paper, coordinated optimal power management at the supply/demand side of a given AES is studied with regard to different objectives and related technical/environmental constraints. The optimal power management problem is formulated as a mixed...

  8. Risk management for independent power projects

    International Nuclear Information System (INIS)

    Owen, J.L.

    1993-01-01

    Independent Power, where electric utilities or other bulk electric power users contract with individual electric power generation facilities to meet their projected long term power needs, has grown dramatically over the past ten years or more. This concept, to contract with Independent Power Producers (IPP), is not a new concept and in fact goes back to the early formation of the electric power industry in this country and worldwide. Successful Risk Management is the foundation for ultimate project completion and operation in fulfilling the expectations of all parties. The primary risks associated with the development of Independent Power projects include: predicting long term fuel availability and cost; predicting long term price for the deliverable of electricity; site selection, site characteristics and permitting; innovative or evolving technology; project execution (design and construction), and; lifetime O ampersand M costs and plant reliability. This paper focuses on the risks inherent in the development of IPPs and addresses the management of these risks

  9. Reliability Analysis of Single-Phase PV Inverters with Reactive Power Injection at Night Considering Mission Profiles

    DEFF Research Database (Denmark)

    Anurag, Anup; Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    loading, considering the operation outside active feed-in hours. An analytical lifetime model is then employed for lifetime quantization based on the Palgrem Miner rule. Thereafter, considering the lifetime reduction of the PV inverter under different mission profiles with reactive power injection......The widespread adoption of mixed renewables urgently require reactive power exchange at various feed-in points of the utility grid. Photovoltaic (PV) inverters are able to provide reactive power in a decentralized manner at the grid-connection points even outside active power feed-in operation......, especially at night when there is no solar irradiance. This serves as a motivation for utilizing the PV inverters at night for reactive power compensation. Thus, an analysis on the impact of reactive power injection by PV inverters outside feed-in operation on the thermal performance and the reliability has...

  10. Measurement based analysis of active and reactive power losses in a distribution network with wind farms and CHPs

    DEFF Research Database (Denmark)

    Lund, Torsten

    2007-01-01

    The paper presents an investigation of the active and reactive power losses in a distribution network with wind turbines and combined heat and power plants. The investigation is based on 15 min average power measurements and load flow calculations in the power system simulation tool PowerFactory...

  11. 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.

  12. Knowledge-based systems for power management

    Science.gov (United States)

    Lollar, L. F.

    1992-01-01

    NASA-Marshall's Electrical Power Branch has undertaken the development of expert systems in support of further advancements in electrical power system automation. Attention is given to the features (1) of the Fault Recovery and Management Expert System, (2) a resource scheduler or Master of Automated Expert Scheduling Through Resource Orchestration, and (3) an adaptive load-priority manager, or Load Priority List Management System. The characteristics of an advisory battery manager for the Hubble Space Telescope, designated the 'nickel-hydrogen expert system', are also noted.

  13. Optimal reactive power planning for distribution systems considering intermittent wind power using Markov model and genetic algorithm

    Science.gov (United States)

    Li, Cheng

    Wind farms, photovoltaic arrays, fuel cells, and micro-turbines are all considered to be Distributed Generation (DG). DG is defined as the generation of power which is dispersed throughout a utility's service territory and either connected to the utility's distribution system or isolated in a small grid. This thesis addresses modeling and economic issues pertaining to the optimal reactive power planning for distribution system with wind power generation (WPG) units. Wind farms are inclined to cause reverse power flows and voltage variations due to the random-like outputs of wind turbines. To deal with this kind of problem caused by wide spread usage of wind power generation, this thesis investigates voltage and reactive power controls in such a distribution system. Consequently static capacitors (SC) and transformer taps are introduced into the system and treated as controllers. For the purpose of getting optimum voltage and realizing reactive power control, the research proposes a proper coordination among the controllers like on-load tap changer (OLTC), feeder-switched capacitors. What's more, in order to simulate its uncertainty, the wind power generation is modeled by the Markov model. In that way, calculating the probabilities for all the scenarios is possible. Some outputs with consecutive and discrete values have been used for transition between successive time states and within state wind speeds. The thesis will describe the method to generate the wind speed time series from the transition probability matrix. After that, utilizing genetic algorithm, the optimal locations of SCs, the sizes of SCs and transformer taps are determined so as to minimize the cost or minimize the power loss, and more importantly improve voltage profiles. The applicability of the proposed method is verified through simulation on a 9-bus system and a 30-bus system respectively. At last, the simulation results indicate that as long as the available capacitors are able to sufficiently

  14. Power management techniques for integrated circuit design

    CERN Document Server

    Chen, Ke-Horng

    2016-01-01

    This book begins with the premise that energy demands are directing scientists towards ever-greener methods of power management, so highly integrated power control ICs (integrated chip/circuit) are increasingly in demand for further reducing power consumption. * A timely and comprehensive reference guide for IC designers dealing with the increasingly widespread demand for integrated low power management * Includes new topics such as LED lighting, fast transient response, DVS-tracking and design with advanced technology nodes * Leading author (Chen) is an active and renowned contributor to the power management IC design field, and has extensive industry experience * Accompanying website includes presentation files with book illustrations, lecture notes, simulation circuits, solution manuals, instructors manuals, and program downloads.

  15. Chemistry management system for nuclear power plants

    International Nuclear Information System (INIS)

    Nagasawa, Katsumi; Maeda, Katsuji

    1998-01-01

    Recently, the chemistry management in the nuclear power plants has been changing from the problem solution to the predictive diagnosis and maintenance. It is important to maintain the integrity of plant operation by an adequate chemistry control. For these reasons, many plant operation data and chemistry analysis data should be collected and treated effectively to evaluate chemistry condition of the nuclear power plants. When some indications of chemistry anomalies occur, quick and effective root cause evaluation and countermeasures should be required. The chemistry management system has been developed as to provide sophisticate chemistry management in the nuclear power plants. This paper introduces the concept and functions of the chemistry management system for the nuclear power plants. (author)

  16. Experimental evaluation of reactivity constraints for the closed-loop control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.; Lanning, D.D.; Ray, A.

    1984-01-01

    General principles for the closed-loop, digital control of reactor power have been identified, quantitatively enumerated, and experimentally demonstrated on the 5 MWt Research Reactor, MITR-II. The basic concept is to restrict the net reactivity so that it is always possible to make the reactor period infinite at the desired termination point of a transient by reversing the direction of motion of whatever control mechanism is associated with the controller. This capability is formally referred to as ''feasibility of control''. A series of ten experiments have been conducted over a period of eighteen months to demonstrate the efficacy of this property for the automatic control of reactor power. It has been shown that a controller which possesses this property is capable of both raising and lowering power in a safe, efficient manner while using a control rod of varying differential worth, that the reactivity constraints are a sufficient condition for the automatic control of reactor power, and that the use of a controller based on reactivity constraints can prevent overshoots either due to attempts to control a transient with a control rod of insufficient differential worth or due to failure to properly estimate when to commence rod insertion. Details of several of the more significant tests are presented together with a discussion of the rationale for the development of closed-loop control in large commercial power systems. Specific consideration is given to the motivation for designing a controller based on feasibility of control and the associated licensing issues

  17. Combined Active and Reactive Power Control of Wind Farms based on Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Wang, Jianhui

    2017-01-01

    This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power control, the proposed control scheme considers the significant impact of active power on voltage variations due to the low X=R ratio...... of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive power, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate...... the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme....

  18. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    .g. Germany and Italy. Those advanced features can be provided by next generation PV systems, and will be enhanced in the future to ensure an even efficient and reliable utilization of PV systems. In light of this, Reactive Power Injection (RPI) strategies for single-phase PV systems are explored...... in this paper. The RPI possibilities are: a) constant average active power control, b) constant active current control, c) constant peak current control and d) thermal optimized control strategy. All those strategies comply with the currently active grid codes, but are with different objectives. The proposed...... RPI strategies are demonstrated firstly by simulations and also tested experimentally on a 1 kW singe-phase grid-connected system in LVRT operation mode. Those results show the effectiveness and feasibilities of the proposed strategies with reactive power control during LVRT operation. The design...

  19. Reactive power generation in high speed induction machines by continuously occurring space-transients

    Science.gov (United States)

    Laithwaite, E. R.; Kuznetsov, S. B.

    1980-09-01

    A new technique of continuously generating reactive power from the stator of a brushless induction machine is conceived and tested on a 10-kw linear machine and on 35 and 150 rotary cage motors. An auxiliary magnetic wave traveling at rotor speed is artificially created by the space-transient attributable to the asymmetrical stator winding. At least two distinct windings of different pole-pitch must be incorporated. This rotor wave drifts in and out of phase repeatedly with the stator MMF wave proper and the resulting modulation of the airgap flux is used to generate reactive VA apart from that required for magnetization or leakage flux. The VAR generation effect increases with machine size, and leading power factor operation of the entire machine is viable for large industrial motors and power system induction generators.

  20. EBRPOCO - a program to calculate detailed contributions of power reactivity components of EBR-II

    International Nuclear Information System (INIS)

    Meneghetti, D.; Kucera, D.A.

    1981-01-01

    The EBRPOCO program has been developed to facilitate the calculations of the power coefficients of reactivity of EBR-II loadings. The program enables contributions of various components of the power coefficient to be delineated axially for every subassembly. The program computes the reactivity contributions of the power coefficients resulting from: density reduction of sodium coolant due to temperature; displacement of sodium coolant by thermal expansions of cladding, structural rods, subassembly cans, and lower and upper axial reflectors; density reductions of these steel components due to temperature; displacement of bond-sodium (if present) in gaps by differential thermal expansions of fuel and cladding; density reduction of bond-sodium (if present) in gaps due to temperature; free axial expansion of fuel if unrestricted by cladding or restricted axial expansion of fuel determined by axial expansion of cladding. Isotopic spatial contributions to the Doppler component my also be obtained. (orig.) [de

  1. Long term storage effects of irradiated fuel elements on power distribution and reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Ponzoni Filho, P.; Sato, Sadakatu; Santos, Teresinha Ipojuca Cardoso T.I.C.; Fernandes Vanderlei Borba [FURNAS, Rio de Janeiro, RJ (Brazil); Fetterman, R.J. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

    1995-12-31

    The ALPHA/PHOENIX-P/ANC (APA) code package was used to calculate the pin by pin power distribution and reactivity for Angra 1 Power Plant, Cycle 5. The Angra 1 Cycle 5 core was loaded with several irradiated fuel elements which were stored in the Spent Fuel Pool (SFP) for more than 8 years. Generally, neutronic codes take into account the buildup and depletion of just a few key fission, products such as Sm-149. In this paper it is shown that the buildup effects of other fission products must be considered for fuel which has been out of the core for significant periods of time. Impacts of these other fission products can change core reactivity and power distribution. (author). 3 refs, 4 figs, 4 tabs.

  2. Long term storage effects of irradiated fuel elements on power distribution and reactivity

    International Nuclear Information System (INIS)

    Ponzoni Filho, P.; Sato, Sadakatu; Santos, Teresinha Ipojuca Cardoso T.I.C.; Fernandes Vanderlei Borba; Fetterman, R.J.

    1995-01-01

    The ALPHA/PHOENIX-P/ANC (APA) code package was used to calculate the pin by pin power distribution and reactivity for Angra 1 Power Plant, Cycle 5. The Angra 1 Cycle 5 core was loaded with several irradiated fuel elements which were stored in the Spent Fuel Pool (SFP) for more than 8 years. Generally, neutronic codes take into account the buildup and depletion of just a few key fission, products such as Sm-149. In this paper it is shown that the buildup effects of other fission products must be considered for fuel which has been out of the core for significant periods of time. Impacts of these other fission products can change core reactivity and power distribution. (author). 3 refs, 4 figs, 4 tabs

  3. Sensitivity analysis of power excursion in RSG-GAS reactor due to reactivity insertion

    International Nuclear Information System (INIS)

    Pinem, Surian; Sembiring, Tagor Malem

    2002-01-01

    Reactor kinetics has a very important role in reactor operation safety and nuclear reactor control. One of the important aspects in reactor kinetics is power behavior as function of time due to chain reaction in the core. The calculation was performed using kinetic equation and feedback reactivity and evaluated using static power coefficient. Analysis was performed for oxide 250 g, silicide 250 g and silicide 300 g fuel elements with insertion of positive reactivity, negative reactivity and reactivity close to delay neutron fraction. The calculation of power excursion sensitivity showed that the insertion of 0,5 % Δk/k, in the fuel element of silicide 300 g is bigger 5 % than the one of oxide 250 g or silicide 250 g. If inserted by - 1,2 % Δk/k, there is no change among three fuel elements. Therefore, in kinetic point of view, it is showed there is no significant influence in the RSG-GAS reactor operation safety is the current core of oxide 250 g is converted to silicide 250 g or to silicide 300 g

  4. Core concept of fast power reactor with zero sodium void reactivity

    International Nuclear Information System (INIS)

    Matveev, V.I.; Chebeskov, A.N.; Krivitsky, I.Y.

    1991-01-01

    The paper presents a core concept of BN-800 - type fast power reactor with zero sodium void reactivity (SVR). Consideration is given to the layout-and some design features of such a core. Some considerations on the determination of the required SVR value as one of the fast reactor safety criteria in accidents with coolant boiling are presented. Some methodical considerations an the development of calculation models that give a correct description of the new core features are stated. The results of the integral SVR calculation studies are included. reactivity excursions under different scenarios of sodium boiling are estimated, some corrections into the calculated SVR value are discussed. (author)

  5. Effect of reactivity insertion rate on peak power and temperatures in swimming pool type research reactor

    International Nuclear Information System (INIS)

    Khan, L.A.; Jabbar, A.; Anwar, A.R.; Ahmad, N.

    1998-01-01

    It is essential to study the reactor behavior under different accidental conditions and take proper measures for its safe operation. We have studied the effect of reactivity insertion, with and without scram conditions, on peak power and temperatures of fuel, cladding and coolant in typical swimming pool type research reactor. The reactivity ranging from 1 $ to 2 $ and insertion times from 0.25 to 1 second have been considered. The computer code PARET has been used and results are presented in this article. (author)

  6. Quality management in nuclear power plant technology

    International Nuclear Information System (INIS)

    Brosche, D.; Ehrnsperger, K.

    2001-01-01

    Quality assurance and therefore quality management are essential preconditions for the safety and availability of nuclear power plants. On the basis of the rules of the Kerntechnischer Ausschuss KTA 1401 the quality management in the former Bayernwerk AG and the Bayernwerk Kernenergie GmbH as well as in the Arbeitsgemeinschaft Auftragnehmerbeurteilung within the VGB Technical Association of Large Power Plant Operators is described. (orig.) [de

  7. Composable and Predictable Power Management

    NARCIS (Netherlands)

    Nelson, A.T.

    2014-01-01

    The functionality of embedded systems is ever growing. The computational power of embedded systems is growing to match this demand, with embedded multiprocessor systems becoming more common. The limitations of embedded systems are not always related to chip size but are commonly due to energy and/or

  8. Power management for energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Gybel Hovgaard, T.

    2013-02-15

    In this thesis, we consider the control of two different industrial applications that belong at either end of the electricity grid; a power consumer in the form of a commercial refrigeration system, and wind turbines for power production. Our primary studies deal with economic model predictive control of a commercial multi-zone refrigeration system, consisting of several cooling units that share a common compressor, and is used to cool multiple areas or rooms, e.g., in supermarkets. For control of the commercial refrigeration application as well as the wind turbine application, we propose an economic optimizing model predictive controller, economic MPC. Our investigations are primarily concerned with: 1) modeling of the applications to suit the chosen control framework; 2) formulating the MPC controller laws to overcome challenges introduced by the industrial applications, and defining economic objectives that reect the real physics of the systems as well as our control objectives; 3) solving the involved, non-trivial optimization problems eciently in real-time; 4) demonstrating the feasibility and potential of the proposed methods by extensive simulation and comparison with existing control methods and evaluation of data from systems in actual operation. We demonstrate, i.a., substantial cost savings, on the order of 30 %, compared to a standard thermostat-based supermarket refrigeration system and show how our methods exhibit sophisticated demand response to real-time variations in electricity prices. Violations of the temperature ranges can be kept at a very low frequency of occurrence inspite of the presence of uncertainty. For the power output from wind turbines, ramp rates, as low a 3 % of the rated power per minute, can be effectively ensured with the use of energy storage and we show how the active use of rotor inertia as an additional energy storage can reduce the needed storage capacity by up to 30 % without reducing the power output. (Author)

  9. Nuclear power plants management from Chernobyl

    International Nuclear Information System (INIS)

    Blanc, P.

    1996-01-01

    The Three mile island and Chernobyl accidents developed a change for the operation and management of nuclear power plants. The present articles studies the state of the art the management of NPPs, the foundation of INPO and WANO and the future of operation in NPPs

  10. Electric power generation and uranium management

    International Nuclear Information System (INIS)

    Szergenyi, Istvan

    1989-01-01

    Assuming the present trend of nuclear power generation growth, the ratio of nuclear energy in the world power balance will double by the turn of the century. The time of reasonably exploited uranium resources can be predicted as a few decades. Therefore, new nuclear reactor types and more rational uranium management is needed to prolong life of known uranium resources. It was shown how can a better uranium utilization be expected by closed fuel cycles, and what advantages in uranium management can be expected by a better co-operation between small countries and big powers. (R.P.) 16 refs.; 4 figs

  11. Knowledge management in nuclear power plants

    International Nuclear Information System (INIS)

    Cal, C. de la; Barasoain, F.; Buedo, J. L.

    2013-01-01

    This article aims to show the importance of knowledge management from different perspectives. In this first part part of the article, the overall approach that performs CNAT of knowledge management is described. In the second part, a specific aspect of knowledge management in ANAV, tacit knowledge transfer is showed. finally, the third part discusses the strategies and actions that are followed in CNCO for knowledge management. All this aims to show an overview of knowledge management held in the Spanish Nuclear Power Plants. (Author)

  12. Reactivity management and burn-up management on JRR-3 silicide-fuel-core

    International Nuclear Information System (INIS)

    Kato, Tomoaki; Araki, Masaaki; Izumo, Hironobu; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji

    2007-08-01

    On the conversion from uranium-aluminum-dispersion-type fuel (aluminide fuel) to uranium-silicon-aluminum-dispersion-type fuel (silicide fuel), uranium density was increased from 2.2 to 4.8 g/cm 3 with keeping uranium-235 enrichment of 20%. So, burnable absorbers (cadmium wire) were introduced for decreasing excess reactivity caused by the increasing of uranium density. The burnable absorbers influence reactivity during reactor operation. So, the burning of the burnable absorbers was studied and the influence on reactor operation was made cleared. Furthermore, necessary excess reactivity on beginning of operation cycle and the time limit for restart after unplanned reactor shutdown was calculated. On the conversion, limit of fuel burn-up was increased from 50% to 60%. And the fuel exchange procedure was changed from the six-batch dispersion procedure to the fuel burn-up management procedure. The previous estimation of fuel burn-up was required for the planning of fuel exchange, so that the estimation was carried out by means of past operation data. Finally, a new fuel exchange procedure was proposed for effective use of fuel elements. On the procedure, burn-up of spent fuel was defined for each loading position. The average length of fuel's staying in the core can be increased by two percent on the procedure. (author)

  13. Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2016-01-01

    Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

  14. Reactive Power Support of Electrical Vehicle Charging Station Upgraded with Flywheel Energy Storage System

    DEFF Research Database (Denmark)

    SUN, BO; Dragicevic, Tomislav; Savaghebi, Mehdi

    2015-01-01

    Electrical vehicles (EVs) are presenting increasingly potential to replace the conventional fossil fuel based vehicles due to environmental friendly characteristic. Accordingly, Charging Stations (CS), as an intermediate between grid and large numbers of EVs, are supposed to have more critical...... influence on future smart transportation network. This paper explores an off-board charging station upgraded with flywheel energy storage system that could provide a reactive power support to the grid utility. A supervisory control scheme based on distributed bus signaling is proposed to coordinate...... the operation of each component in the system. As a result, the charging station could supply the reactive power support to the utility grid without compromising the charging algorithm and preserve the battery’s lifetime. Finally, the real-time simulation results based on dSPACE1006 verifies the proposed...

  15. An Optimized Reactive Power Control of Distributed Solar Inverters in Low Voltage Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2011-01-01

    This study examines the reactive power ancillary services of solar inverters which are connected to low voltage (LV) distribution networks by giving attention to the grid voltage support service and grid losses. Two typical reference LV distribution network models as suburban and farm...... are introduced from the literature in order to evaluate contribution of two static droop strategies cosφ(P) and Q(U) on the grid voltage. Photovoltaic (PV) hosting capacities of the suburban and farm networks are estimated and the most predominant limitations of connecting more solar inverters are emphasized...... for each network type. Regarding the overloading of MV/LV distribution transformers, overloading of lines and the grid overvoltage limitations, new local grid voltage support methods (cosφ(P,U) and Q(U,P)) are also proposed. Resulting maximum allowable penetration levels with different reactive power...

  16. A Preliminary Analysis of the Economics of Using Distributed Energy as a Source of Reactive Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL; King, Thomas F [ORNL

    2006-04-01

    A major blackout affecting 50 million people in the Northeast United States, where insufficient reactive power supply was an issue, and an increased number of filings made to the Federal Energy Regulatory Commission by generators for reactive power has led to a closer look at reactive power supply and compensation. The Northeastern Massachusetts region is one such area where there is an insufficiency in reactive power compensation. Distributed energy due to its close proximity to loads seems to be a viable option for solving any present or future reactive power shortage problems. Industry experts believe that supplying reactive power from synchronized distributed energy sources can be 2 to 3 times more effective than providing reactive support in bulk from longer distances at the transmission or generation level. Several technology options are available to supply reactive power from distributed energy sources such as small generators, synchronous condensers, fuel cells or microturbines. In addition, simple payback analysis indicates that investments in DG to provide reactive power can be recouped in less than 5 years when capacity payments for providing reactive power are larger than $5,000/kVAR and the DG capital and installation costs are lower than $30/kVAR. However, the current institutional arrangements for reactive power compensation present a significant barrier to wider adoption of distributed energy as a source of reactive power. Furthermore, there is a significant difference between how generators and transmission owners/providers are compensated for reactive power supplied. The situation for distributed energy sources is even more difficult, as there are no arrangements to compensate independent DE owners interested in supplying reactive power to the grid other than those for very large IPPs. There are comparable functionality barriers as well, as these smaller devices do not have the control and communications requirements necessary for automatic

  17. Reactivation of nuclear power plant construction projects. Plant status, policy issues and regulatory options

    International Nuclear Information System (INIS)

    Spangler, M.B.

    1986-07-01

    Prior to the TMI-2 accident on March 28, 1979, four nuclear power plant units that had previously been issued a construction permit were cancelled, principally because of reduced projections of regional power demand. Since that time, an additional 31 units with CPs have been cancelled and eight units deferred. On December 23, 1985 one of the deferred units (Limerick-2) was reactivated and construction resumed. The primary objective of this policy study is to identify the principal issues requiring office-level consideration in the event of reactivation of the construction of one or more of the nuclear power plants falling into two categories: (1) LWR units issued a construction permit whose construction has been cancelled, and (2) LWR units whose construction has been deferred. The study scope is limited to identifying regulatory issues or questions deserving analysis rather than providing, at this time, answers or recommended actions. Five tasks are addressed: a tabulation and discussion of the status of all cancelled and deferred LWR units; and identification of potential safety and environmental issues; an identification of regulatory or policy issues and needed information to determine the desirability of revising certain rules and policies; and identification of regulatory options and decision criteria; and an identification of decision considerations in determining staff requirements and organizational coordination of LWR reactivation policy and implementation efforts. 41 refs

  18. Modified Monkey Optimization Algorithm for Solving Optimal Reactive Power Dispatch Problem

    Directory of Open Access Journals (Sweden)

    Kanagasabai Lenin

    2015-04-01

    Full Text Available In this paper, a novel approach Modified Monkey optimization (MMO algorithm for solving optimal reactive power dispatch problem has been presented. MMO is a population based stochastic meta-heuristic algorithm and it is inspired by intelligent foraging behaviour of monkeys. This paper improves both local leader and global leader phases.  The proposed (MMO algorithm has been tested in standard IEEE 30 bus test system and simulation results show the worthy performance of the proposed algorithm in reducing the real power loss.

  19. Investigation of Reactive Power Control Effects on Flicker and Harmonics Emission of a DFIG Wind Turbine

    Directory of Open Access Journals (Sweden)

    Amir Nagizadeh Ghoogdareh

    2013-01-01

    Full Text Available One of the most important power quality aspects in wind farms is voltage fluctuation or flicker which should be investigated due to the nature of wind speed variations. These variations result in power and voltage fluctuations at the load bus. Moreover, the wind generation systems may be assumed as a harmonics source because of their power electronic converters. There are numerous factors that affect flicker and harmonic emission of grid-connected wind turbines during continuous operation, such as wind characteristics (e.g. mean wind speed, turbulence intensity, type of generator and grid conditions (e.g. short circuit capacity, grid impedance angle. In this paper, an IEC based flickermeter is first modeled and then a variable speed wind turbine has been simulated by Matlab/Simulink software. The flicker and harmonics emissions of wind turbines equipped with DFIG during continuous operation and using output reactive control are investigated. The simulation results show that control of wind turbine output reactive power is an effective means for flicker mitigation during continuous operation. However, there should be a compromise between flicker reduction and harmonics level increase to enhance the whole power quality of wind turbine.

  20. Managing the first nuclear power plant project

    International Nuclear Information System (INIS)

    2007-05-01

    Energy is essential for national development. Nearly every aspect of development - from reducing poverty and raising living standards to improving health care, industrial and agricultural productivity - requires reliable access to modern energy resources. States may have different reasons for considering starting a nuclear power project to achieve their national energy needs, such as: lack of available indigenous energy resources, the desire to reduce dependence upon imported energy, the need to increase the diversity of energy resources and/or mitigation of carbon emission increases. The start of a nuclear power plant project involves several complex and interrelated activities with long duration. Experience shows that the time between the initial policy decision by a State to consider nuclear power up to the start of operation of its first nuclear power plant is about 10 to 15 years and that before specific project management can proceed, several key infrastructure issues have to be in place. The proper management of the wide scope of activities to be planned and implemented during this period represents a major challenge for the involved governmental, utility, regulatory, supplier and other supportive organizations. The main focus is to ensure that the project is implemented successfully from a commercial point of view while remaining in accordance with the appropriate engineering and quality requirements, safety standards and security guides. This publication is aimed at providing guidance on the practical management of a first nuclear power project in a country. There are many other issues, related to ensuring that the infrastructure in the country has been prepared adequately to ensure that the project will be able to be completed, that are only briefly addressed in this publication. The construction of the first nuclear power plant is a major undertaking for any country developing a nuclear power programme. Worldwide experience gained in the last 50 years

  1. Power Electronics Thermal Management R&D

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert; Bennion, Kevin

    2016-06-08

    This project will develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter designs). The use of WBG-based devices in automotive power electronics will improve efficiency and increase driving range in electric-drive vehicles; however, the implementation of this technology is limited, in part, due to thermal issues. This project will develop system-level thermal models to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

  2. Hybrid Power Management-Based Vehicle Architecture

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    Hybrid Power Management (HPM) is the integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications (s ee figure). The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a primary power source, and possibly other power sources, that provides all power to a common energy storage system that is used to power the drive motors and vehicle accessory systems. This architecture also provides power as an emergency power system. Each component is independent, permitting it to be optimized for its intended purpose. The key element of HPM is the energy storage system. All generated power is sent to the energy storage system, and all loads derive their power from that system. This can significantly reduce the power requirement of the primary power source, while increasing the vehicle reliability. Ultracapacitors are ideal for an HPM-based energy storage system due to their exceptionally long cycle life, high reliability, high efficiency, high power density, and excellent low-temperature performance. Multiple power sources and multiple loads are easily incorporated into an HPM-based vehicle. A gas turbine is a good primary power source because of its high efficiency, high power density, long life, high reliability, and ability to operate on a wide range of fuels. An HPM controller maintains optimal control over each vehicle component. This flexible operating system can be applied to all vehicles to considerably improve vehicle efficiency, reliability, safety, security, and performance. The HPM-based vehicle architecture has many advantages over conventional vehicle architectures. Ultracapacitors have a much longer cycle life than batteries, which greatly improves system reliability, reduces life-of-system costs, and reduces environmental impact as ultracapacitors will probably never need to be

  3. Error management process for power stations

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Takeda, Daisuke; Fujimoto, Junzo; Nagasaka, Akihiko

    2016-01-01

    The purpose of this study is to establish 'error management process for power stations' for systematizing activities for human error prevention and for festering continuous improvement of these activities. The following are proposed by deriving concepts concerning error management process from existing knowledge and realizing them through application and evaluation of their effectiveness at a power station: an entire picture of error management process that facilitate four functions requisite for maraging human error prevention effectively (1. systematizing human error prevention tools, 2. identifying problems based on incident reports and taking corrective actions, 3. identifying good practices and potential problems for taking proactive measures, 4. prioritizeng human error prevention tools based on identified problems); detail steps for each activity (i.e. developing an annual plan for human error prevention, reporting and analyzing incidents and near misses) based on a model of human error causation; procedures and example of items for identifying gaps between current and desired levels of executions and outputs of each activity; stages for introducing and establishing the above proposed error management process into a power station. By giving shape to above proposals at a power station, systematization and continuous improvement of activities for human error prevention in line with the actual situation of the power station can be expected. (author)

  4. Remanent life management of nuclear power plants

    International Nuclear Information System (INIS)

    Pinedo, J.; Gomez Santamaria, J.

    1995-01-01

    The concept of life in the nuclear power plants is very special. The main aceptions are: design life, economic life and useful life. The good management of NPP will do the prolongation of the life in the NPP. The remanent of management life summarizes certain activities in order to prolong the lifetime of the NPP. This article presents the activities of the RML program, the technological program and its benefits

  5. Reduction of DC-link Capacitor in Case of Cascade Multilevel Converters by means of Reactive Power Control

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Wang, Huai; Liserre, Marco

    2014-01-01

    A method to selectively control the amount of dc link voltage ripple by processing desired reactive power by a DC/DC converter in isolated AC/DC or AC/DC/AC system is proposed. The concept can reduce the dc link capacitors used for balancing the input and output power and thereby limiting...... the voltage ripple. It allows the use of smaller dc link capacitor and hence a longer lifetime and at the same time high power density and low cost can be achieved. The isolated DC/DC converter is controlled to process the desired reactive power in addition to the active power. The control system to achieve...

  6. A new algorithm for optimum voltage and reactive power control for minimizing transmission lines losses

    International Nuclear Information System (INIS)

    Ghoudjehbaklou, H.; Danai, B.

    2001-01-01

    Reactive power dispatch for voltage profile modification has been of interest to power utilities. Usually local bus voltages can be altered by changing generator voltages, reactive shunts, ULTC transformers and SVCs. Determination of optimum values for control parameters, however, is not simple for modern power system networks. Heuristic and rather intelligent algorithms have to be sought. In this paper a new algorithm is proposed that is based on a variant of a genetic algorithm combined with simulated annealing updates. In this algorithm a fuzzy multi-objective a approach is used for the fitness function of the genetic algorithm. This fuzzy multi-objective function can efficiently modify the voltage profile in order to minimize transmission lines losses, thus reducing the operating costs. The reason for such a combination is to utilize the best characteristics of each method and overcome their deficiencies. The proposed algorithm is much faster than the classical genetic algorithm and cna be easily integrated into existing power utilities software. The proposed algorithm is tested on an actual system model of 1284 buses, 799 lines, 1175 fixed and ULTC transformers, 86 generators, 181 controllable shunts and 425 loads

  7. Recursive Pyramid Algorithm-Based Discrete Wavelet Transform for Reactive Power Measurement in Smart Meters

    Directory of Open Access Journals (Sweden)

    Mahin K. Atiq

    2013-09-01

    Full Text Available Measurement of the active, reactive, and apparent power is one of the most fundamental tasks of smart meters in energy systems. Recently, a number of studies have employed the discrete wavelet transform (DWT for power measurement in smart meters. The most common way to implement DWT is the pyramid algorithm; however, this is not feasible for practical DWT computation because it requires either a log N cascaded filter or O (N word size memory storage for an input signal of the N-point. Both solutions are too expensive for practical applications of smart meters. It is proposed that the recursive pyramid algorithm is more suitable for smart meter implementation because it requires only word size storage of L × Log (N-L, where L is the length of filter. We also investigated the effect of varying different system parameters, such as the sampling rate, dc offset, phase offset, linearity error in current and voltage sensors, analog to digital converter resolution, and number of harmonics in a non-sinusoidal system, on the reactive energy measurement using DWT. The error analysis is depicted in the form of the absolute difference between the measured and the true value of the reactive energy.

  8. Management of delayed nuclear power plant projects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    According to the available information at the IAEA PRIS (Power Reactor Information System) at the end of 1998 there were more than 40 nuclear power plant projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules showed large variations due to several issues, including financial, economic and public opinion factors. Taking into account the number of projects with several years delay in their original schedules, it was considered useful to identify the subject areas where exchange of experience among Member States would be mutually beneficial in identification of problems and development of guidance for successful management of the completion of these delayed projects. A joint programme of the IAEA Departments of Nuclear Energy (Nuclear Power Engineering Section) and Technical Co-operation (Europe Section, with additional support from the Latin America and West Asia Sections) was set up during the period 1997-1998. The specific aim of the programme was to provide assistance in the management of delayed nuclear power plants regarding measures to maintain readiness for resuming the project implementation schedule when the conditions permit. The integration of IAEA interdepartmental resources enabled the participation of 53 experts from 14 Member States resulting in a wider exchange of experience and dissemination of guidance. Under the framework of the joint programme, senior managers directly responsible for delayed nuclear power plant projects identified several issues or problem areas that needed to be addressed and guidance on management be provided. A work plan for the development of several working documents, addressing the different issues, was established. Subsequently these documents were merged into a single one to produce the present publication. This publication provides information and practical examples on necessary management actions to preserve

  9. Management of delayed nuclear power plant projects

    International Nuclear Information System (INIS)

    1999-09-01

    According to the available information at the IAEA PRIS (Power Reactor Information System) at the end of 1998 there were more than 40 nuclear power plant projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules showed large variations due to several issues, including financial, economic and public opinion factors. Taking into account the number of projects with several years delay in their original schedules, it was considered useful to identify the subject areas where exchange of experience among Member States would be mutually beneficial in identification of problems and development of guidance for successful management of the completion of these delayed projects. A joint programme of the IAEA Departments of Nuclear Energy (Nuclear Power Engineering Section) and Technical Co-operation (Europe Section, with additional support from the Latin America and West Asia Sections) was set up during the period 1997-1998. The specific aim of the programme was to provide assistance in the management of delayed nuclear power plants regarding measures to maintain readiness for resuming the project implementation schedule when the conditions permit. The integration of IAEA interdepartmental resources enabled the participation of 53 experts from 14 Member States resulting in a wider exchange of experience and dissemination of guidance. Under the framework of the joint programme, senior managers directly responsible for delayed nuclear power plant projects identified several issues or problem areas that needed to be addressed and guidance on management be provided. A work plan for the development of several working documents, addressing the different issues, was established. Subsequently these documents were merged into a single one to produce the present publication. This publication provides information and practical examples on necessary management actions to preserve

  10. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately es...

  11. Adaptive reactive power control of PV power plants for improved power transfer capability under ultra-weak grid conditions

    DEFF Research Database (Denmark)

    Yang, Dongsheng; Wang, Xiongfei; Liu, Fangcheng

    2017-01-01

    The Photovoltaic (PV) power plants are usually deployed in remote areas with the high solar irradiance, and their power transfer capabilities can be greatly limited by the large impedance of long-distance transmission lines. This paper investigates first the power transfer limit of the PV power p...

  12. Fuel-Cell-Powered Vehicle with Hybrid Power Management

    Science.gov (United States)

    Eichenberg, Dennis J.

    2010-01-01

    Figure 1 depicts a hybrid electric utility vehicle that is powered by hydrogenburning proton-exchange-membrane (PEM) fuel cells operating in conjunction with a metal hydride hydrogen-storage unit. Unlike conventional hybrid electric vehicles, this vehicle utilizes ultracapacitors, rather than batteries, for storing electric energy. This vehicle is a product of continuing efforts to develop the technological discipline known as hybrid power management (HPM), which is oriented toward integration of diverse electric energy-generating, energy-storing, and energy- consuming devices in optimal configurations. Instances of HPM were reported in five prior NASA Tech Briefs articles, though not explicitly labeled as HPM in the first three articles: "Ultracapacitors Store Energy in a Hybrid Electric Vehicle" (LEW-16876), Vol. 24, No. 4 (April 2000), page 63; "Photovoltaic Power Station With Ultracapacitors for Storage" (LEW- 17177), Vol. 27, No. 8 (August 2003), page 38; "Flasher Powered by Photovoltaic Cells and Ultracapacitors" (LEW-17246), Vol. 27, No. 10 (October 2003), page 37; "Hybrid Power Management" (LEW-17520), Vol. 29, No. 12 (December 2005), page 35; and "Ultracapacitor-Powered Cordless Drill" (LEW-18116-1), Vol. 31, No. 8 (August 2007), page 34. To recapitulate from the cited prior articles: The use of ultracapacitors as energy- storage devices lies at the heart of HPM. An ultracapacitor is an electrochemical energy-storage device, but unlike in a conventional rechargeable electrochemical cell or battery, chemical reactions do not take place during operation. Instead, energy is stored electrostatically at an electrode/electrolyte interface. The capacitance per unit volume of an ultracapacitor is much greater than that of a conventional capacitor because its electrodes have much greater surface area per unit volume and the separation between the electrodes is much smaller.

  13. Nuclear Power Plant Lifetime Management Study (I)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

  14. Nuclear Power Plant Lifetime Management Study (I)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

  15. Power/knowledge and natural resource management

    NARCIS (Netherlands)

    Assche, Van Kristof; Beunen, Raoul; Duineveld, Martijn; Gruezmacher, Monica

    2017-01-01

    In this paper, we present a conceptual framework extending Foucaultian insights on the relations between power and knowledge to link up with current insights into studies of natural resource management (NRM) and more broadly environmental studies. We classify discourses in NRM according to

  16. Care management at Ikata Power Station

    International Nuclear Information System (INIS)

    Sakai, Koji

    1982-01-01

    For operating nuclear power stations safely and economically, it is necessary to control nuclear fuel itself and reactor cores. Nuclear fuel must be controlled consistently in view of quantitative balance and operational method over the whole nuclear fuel cycle of uranium ore, fabrication, burning in reactors and reprocessing, based on the plan of using fuel in electric power companies. The control of the burning in reactors is called core management, and it is important because the users of fuel execute it. For dealing with such core management works, Shikoku Electric Power Co., Inc., has developed the computer code system for grasping the state of fuel exchange and the burning condition in reactors and used it since 1972. The outline of the core management in Ikata Power Station is reported in this paper centering around computing works. The core management works are divided into those at the time of regular inspection and those in operation. In the regular inspection, fuel inspection, fuel exchange and reactor physics test are performed. In operation, the burning condition of fuel is grasped. The technical computations corresponding to these works are explained, and the examples of computations are shown. (Kako, I.)

  17. Power management in hydraulically actuated mobile equipment

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen; Andersen, Torben Ole; Hansen, Michael Rygaard

    2008-01-01

    The focus of the current paper is on the control of hydraulic systems when utilizing the advances that electronic control may bring with regard to power management, prioritized flow sharing and anti-stall, arising from being able to control both pump, valves and engine electronically. A simple mo...

  18. Reactivity control in HTR power plants with respect to passive safety system. Summary

    Energy Technology Data Exchange (ETDEWEB)

    Barnert, H; Kugeler, K [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Sicherheitsforschung und Reaktortechnik

    1996-12-01

    The R and D and Demonstration of the High Temperature Reactor (HTR) is described in overview. The HTR-MODULE power plant, as the most advanced concept, is taken for the description of the reactivity control in general. The idea of the ``modularization of the core`` of the HTR has been developed as the answer on the experiences of the core melt accident at Three Miles Island. The HTR module has two shutdown systems: The ``6 rods``-system for hot shutdown at the ``18 small absorber pebbles units`` - system for cold shutdown. With respect to the definition of ``Passive Systems`` of IAEA-TECDOC-626 the total reactivity control system of the HTR-MODULE is a passive system of category D, because it is an emergency reactor shutdown system based on gravity driven rods, and devices, activated by fail-safe trip logic. But reactivity control of the HTR does not only consist of these engineered safety system but does have a self-acting stabilization by the negative temperature coefficient of the reactivity, being rather effective in reactivity control. Examples from computer calculations are presented, and, in addition, experimental results from the ``Stuck Rod Experiment`` at the AVR reactor in Juelich. On the basis of this the proposal is made that ``self-acting stabilization as a quality of the function`` should be discussed as a new category in addition to the active and passive engineered safety systems, structures and components of IAEA-TECDOC-626. The requirements for a future ``catastrophe-free`` nuclear technology are presented. In the appendix the 7th amendment of the atomic energy act of the Federal Republic of Germany, effective 28 July 94, is given. (author).

  19. Photovoltaic Energy Harvester with Power Management System

    Directory of Open Access Journals (Sweden)

    M. Ferri

    2010-01-01

    Full Text Available We present a photovoltaic energy harvester, realized in 0.35-μm CMOS technology. The proposed system collects light energy from the environment, by means of 2-mm2 on-chip integrated microsolar cells, and accumulates it in an external capacitor. While the capacitor is charging, the load is disconnected. When the energy in the external capacitor is enough to operate the load for a predefined time slot, the load is connected to the capacitor by a power management circuit. The choice of the value of the capacitance determines the operating time slot for the load. The proposed solution is suitable for discrete-time-regime applications, such as sensor network nodes, or, in general, systems that require power supply periodically for short time slots. The power management circuit includes a charge pump, a comparator, a level shifter, and a linear voltage regulator. The whole system has been extensively simulated, integrated, and experimentally characterized.

  20. Technical management of difference in CEPR nuclear power project

    International Nuclear Information System (INIS)

    Guo Ruiting

    2014-01-01

    The Thesis dissertate the application of technical management of difference in CEPR Nuclear Power Project from EPR technical bases, condition of a nuclear power plant site, engineering and procurement, construction, quality management, schedule management and experience feedback aspects. (author)

  1. Intelligent Power Management of hybrid Wind/ Fuel Cell/ Energy Storage Power Generation System

    OpenAIRE

    A. Hajizadeh; F. Hassanzadeh

    2013-01-01

    This paper presents an intelligent power management strategy for hybrid wind/ fuel cell/ energy storage power generation system. The dynamic models of wind turbine, fuel cell and energy storage have been used for simulation of hybrid power system. In order to design power flow control strategy, a fuzzy logic control has been implemented to manage the power between power sources. The optimal operation of the hybrid power system is a main goal of designing power management strategy. The hybrid ...

  2. Radioactive waste management policy for nuclear power

    International Nuclear Information System (INIS)

    Andrei, V.; Glodeanu, F.; Simionov, V.

    1998-01-01

    Nuclear power is part of energy future as a clean and environmental friendly source of energy. For the case of nuclear power, two specific aspects come more often in front of public attention: how much does it cost and what happens with radioactive waste. The competitiveness of nuclear power vs other sources of energy is already proved in many developed and developing countries. As concerns the radioactive wastes treatment and disposal, industrial technologies are available. Even final solutions for disposal of high level radioactive waste, including spent fuel, are now fully developed and ready for large scale implementation. Policies and waste management strategies are established by all countries having nuclear programs. Once, the first nuclear power reactor was commissioned in Romania, and based on the national legal provisions, our company prepared the first issue of a general strategy for radioactive waste management. The general objective of the strategy is to dispose the waste according to adequate safety standards protecting the man and the environment, without undue burden on future generations. Two target objectives were established for long term: an interim spent fuel dry storage facility and a low and intermediate level waste repository. A solution for spent fuel disposal will be implemented in the next decade, based on international experience. Principles for radioactive waste management, recommended by IAEA are closely followed in the activities of our company. The continuity of responsibilities is considered to be very important. The radioactive waste management cost will be supported by the company. A tax on unit price of electricity will be applied. The implementation of radioactive waste management strategy includes as a major component the public information. A special attention will be paid by the company to an information program addressed to different categories of public in order to have a better acceptance of our nuclear power projects

  3. Quality management of nuclear power plants

    International Nuclear Information System (INIS)

    Maxwell, D.A.; Hille, F.J.M.

    1995-01-01

    The paper discusses the various approaches to quality management and the progressive development from traditional quality assurance (QA) concepts through integrated and performance based quality management systems to total quality management. Experience has shown that in many cases the traditional implementation of QA in nuclear power plant life-cycle activities has resulted in limited benefits. The paper outlines the advantages of developing an integrated quality management system, which, besides satisfying the QA standards, focuses on the performance of an organization. This reflects the approach implicit in the proposed revisions of the IAEA QA standards (code and guides). Such a quality management system provides the framework within which processes are controlled to meet the business objectives and is capable of accommodating easily new requirements, such as environmental management. An integrated quality management system should not be focused specifically on regulatory (and hence nuclear safety) issues, but should constitute the whole management system of the organization, of which safety and the environment are of course important elements. The paper gives a practical example of this approach implemented company wide. This approach is similar to other approaches in place or being developed by many Foratom members. The paper also lists the components of total quality management, which is considered to constitute the future direction for the nuclear power industry. The quality management system is the primary vehicle to meet the fundamental objectives, but total quality can only be realized by developing the full potential of people through team work in order to continuously improve the system and the performance of the organization by focusing on internal as well as external customers. (author). 6 refs, 3 figs, 2 tab

  4. Coordination of voltage and reactive power control in the extra high voltage substations based on the example of solutions applied in the national power system

    Directory of Open Access Journals (Sweden)

    Dariusz Kołodziej

    2012-06-01

    Full Text Available This paper presents examples of coordination between automatic voltage and reactive power control systems (ARST covering adjacent and strongly related extra high voltage substations. Included are conclusions resulting from the use of these solutions. The Institute of Power Engineering, Gdańsk Division has developed and deployed ARST systems in the national power system for a dozen or so years.

  5. DC power supplies power management and surge protection for power electronic systems

    CERN Document Server

    Kularatna, Nihal

    2011-01-01

    Modern electronic systems, particularly portable consumer electronic systems and processor based systems, are power hungry, compact, and feature packed. This book presents the most essential summaries of the theory behind DC-DC converter topologies of both linear and switching types. The text discusses power supply characteristics and design specifications based on new developments in power management techniques and modern semiconductors entering into the portable electronics market. The author also addresses off-the-line power supplies, digital control of power supply, power supply protection

  6. Photovoltaic Hosting Capacity of Feeders with Reactive Power Control and Tap Changers

    Energy Technology Data Exchange (ETDEWEB)

    Ceylan, Oğuzhan; Paudyal, Sumit; Bhattarai, Bishnu P.; Myers, Kurt S.

    2017-06-01

    This paper proposes an algorithm to determine photovoltaic (PV) hosting capacity of power distribution networks as a function of number of PV injection nodes, reactive power support from the PVs, and the sub-station load tap changers (LTCs). In the proposed method, several minute by minute simulations are run based on randomly chosen PV injection nodes, daily PV output profiles, and daily load profiles from a pool of high-resolution realistic data set. The simulation setup is built using OpenDSS and MATLAB. The performance of the proposed method is investigated in the IEEE 123-node distribution feeder for multiple scenarios. The case studies are performed particularly for one, two, five and ten PV injection nodes, and looking at the maximum voltage deviations. Case studies show that the PV hosting capacity of the 123-node feeder greatly differs with the number of PV injection nodes. We have also observed that the PV hosting capacity increases with reactive power support and higher tap position of sub-station LTC.

  7. Voltage stability in low voltage microgrids in aspects of active and reactive power demand

    Directory of Open Access Journals (Sweden)

    Parol Mirosław

    2016-03-01

    Full Text Available Low voltage microgrids are autonomous subsystems, in which generation, storage and power and electrical energy consumption appear. In the paper the main attention has been paid to the voltage stability issue in low voltage microgrid for different variants of its operation. In the introduction a notion of microgrid has been presented, and also the issue of influence of active and reactive power balance on node voltage level has been described. Then description of voltage stability issue has been presented. The conditions of voltage stability and indicators used to determine voltage stability margin in the microgrid have been described. Description of the low voltage test microgrid, as well as research methodology along with definition of considered variants of its operation have been presented further. The results of exemplary calculations carried out for the daily changes in node load of the active and reactive power, i.e. the voltage and the voltage stability margin indexes in nodes have been presented. Furthermore, the changes of voltage stability margin indexes depending on the variant of the microgrid operation have been presented. Summary and formulation of conclusions related to the issue of voltage stability in microgrids have been included at the end of the paper.

  8. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  9. Energy management in fuel cell power trains

    International Nuclear Information System (INIS)

    Corbo, P.; Corcione, F.E.; Migliardini, F.; Veneri, O.

    2006-01-01

    In this paper, experimental results obtained on a small size fuel cell power train (1.8 kW) based on a 500 W proton exchange membrane (PEM) stack are reported and discussed with specific regard to energy management issues to be faced for attainment of the maximum propulsion system efficiency. The fuel cell system (FCS) was realized and characterized via investigating the effects of the main operative variables on efficiency. This resulted in an efficiency higher than 30% in a wide power range with a maximum of 38% at medium load. The efficiency of the overall fuel cell power train measured during both steady state and dynamic conditions (European R40 driving cycle) was about 30%. A discussion about the control strategy to direct the power flows is reported with reference to two different test procedures used in dynamic experiments, i.e., load levelled and load following

  10. Management strategies for nuclear power plant outages

    International Nuclear Information System (INIS)

    2006-01-01

    More competitive energy markets have significant implications for nuclear power plant operations, including, among others, the need for more efficient use of resources and effective management of plant activities such as on-line maintenance and outages. Outage management is a key factor for safe, reliable and economic plant performance and involves many aspects: plant policy, coordination of available resources, nuclear safety, regulatory and technical requirements, and all activities and work hazards, before and during the outage. The IAEA has produced this report on nuclear power plant outage management strategies to provide both a summary and an update of a follow-up to a series of technical documents related to practices regarding outage management and cost effective maintenance. The aim of this publication is to identify good practices in outage management: outage planning and preparation, outage execution and post-outage review. As in in the related technical documents, this report aims to communicate these practices in such a way that they can be used by operating organizations and regulatory bodies in Member States. The report was prepared as part of an IAEA project on continuous process improvement. The objective of this project is to increase Member State capabilities in improving plant performance and competitiveness through the utilization of proven engineering and management practices developed and transferred by the IAEA

  11. Loss of Excitation Detection in Doubly Fed Induction Generator by Voltage and Reactive Power Rate

    Directory of Open Access Journals (Sweden)

    M. J. Abbasi

    2016-12-01

    Full Text Available The doubly fed induction generator (DFIG is one of the most popular technologies used in wind power systems. With the growing use of DFIGs and increasing power system dependence on them in recent years, protecting of these generators against internal faults is more considered. Loss of excitation (LOE event is among the most frequent failures in electric generators. However, LOE detection studies heretofore were usually confined to synchronous generators. Common LOE detection methods are based on impedance trajectory which makes the system slow and also prone to interpret a stable power swing (SPS as a LOE fault. This paper suggests a new method to detect the LOE based on the measured variables from the DFIG terminal. In this combined method for LOE detection, the rate of change of both the terminal voltage and the output reactive power are utilized and for SPS detection, the fast Fourier transform (FFT analysis of the output instantaneous active power has been used. The performance of the proposed method was evaluated using Matlab/Simulink interface for various power capacities and operating conditions. The results proved the method's quickness, simplicity and security.

  12. Study on offshore wind farm integration mode and reactive power compensation

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Xiaoyan; Hong, Lijun; Fu, Yang [Shanghai Univ. of Electrical Power (China). Power and Automation Engineering Dept.

    2013-07-01

    Two typical offshore wind farm grid-connected modes are introduced and dynamic characteristics under their modes are compared from the simulation by PSS/E. The result shows that offshore wind farm with VSC-HVDC has better dynamic characteristics on fault isolation, reactive power compensation, and fault ride through ability. In addition, STATCOM has been applied to the offshore wind farm, the simulation results indicates that it can improve the bus voltage stability in fault and maintain the voltage level under a small perturbation.

  13. Smart Shipboard Power System Operation and Management

    Directory of Open Access Journals (Sweden)

    Fotis D. Kanellos

    2016-11-01

    Full Text Available During recent years, optimal electrification of isolated offshore systems has become increasingly important and received extensive attention from the maritime industry. Especially with the introduction of electric propulsion, which has led to a total electrification of shipboard power systems known as all-electric ships (AESs, the need for more cost-effective and emission-aware solutions is augmented. Such onboard systems are prone to sudden load variations due to the changing weather conditions as well as mission profile, thus they require effective power management systems (PMSs to operate optimally under different working conditions. In this paper, coordinated optimal power management at the supply/demand side of a given AES is studied with regard to different objectives and related technical/environmental constraints. The optimal power management problem is formulated as a mixed-integer nonlinear programming (MINLP model and is solved using a metaheuristic algorithm. To show the effectiveness and applicability of the proposed PMS, several test scenarios are implemented and related simulation results are analyzed and compared to those from conventional methods.

  14. Optimization-based reactive power control in HVDC-connected wind power plants

    OpenAIRE

    Schönleber, Kevin; Collados Rodríguez, Carlos; Teixeira Pinto, Rodrigo; Ratés Palau, Sergi; Gomis Bellmunt, Oriol

    2017-01-01

    One application of high–voltage dc (HVdc) systems is the connection of remotely located offshore wind power plants (WPPs). In these systems, the offshore WPP grid and the synchronous main grid operate in decoupled mode, and the onshore HVdc converter fulfills the grid code requirements of the main grid. Thus, the offshore grid can be operated independently during normal conditions by the offshore HVdc converter and the connected wind turbines. In general, it is well known that optimized react...

  15. Environmental Management Audit: Southwestern Power Administration (Southwestern)

    International Nuclear Information System (INIS)

    1993-03-01

    This report documents the results of the Environmental Management Audit completed for the Southwestern Power Administration. During this Audit, activities and records were reviewed and personnel interviewed. The onsite portion of the Southwestern Audit was conducted from November 30 through December 11, 1992, by the US Department of Energy's Office of Environmental Audit (EH-24). EH-24 carries out independent assessments of Department of Energy (DOE) facilities and activities as part of the Assistant Secretary's Environmental Audit Program. This program is designed to evaluate the status of DOE facilities/activities regarding compliance with laws, regulations, DOE Orders, formal written procedures, compliance agreements, and Best Management Practices (BMPs). This internal oversight function plays an important role in improving the compliance status of DOE operations. The Environmental Management Audit stresses DOE's policy that it is the responsibility of line management to conduct operations in an environmentally sound and safe manner. The Environmental Management Audit focuses on management systems and programs, whereas the Environmental Baseline Audit conducted in March 1991 focused on specific compliance issues. The scope of the Southwestern Environmental Management Audit included a review of all systems and functions necessary for effective environmental management. Specific areas of review included: Organizational Structure; Environmental Commitment; Environmental Protection Programs; Formality of Environmental Programs; Internal and External Communication; Staff Resources, Training, and Development; and Program Evaluation, Reporting, and Corrective Action

  16. Computer-assisted power plant management

    International Nuclear Information System (INIS)

    Boettcher, D.

    1990-01-01

    Operating a power plant and keeping it operational is ensured by a multiplicity of technical management subtasks which are cross referenced and based on an extensive inventory of descriptive and operational plant data. These data stocks are still registered in an isolated mode and managed and updated manually. This is a labor intensive, error prone procedure. In this situation, the introduction of a computer-assisted plant management system, whose core is a data-base of assured quality common to all activities, and which contains standardized processing aids fully planned for the subtasks occurring in the plant, is likely to achieve a considerable improvement in the quality of plant management and to relieve the staff of administrative activities. (orig.) [de

  17. Unconfirmed reactive screening tests and their impact on donor management

    International Nuclear Information System (INIS)

    Rahman, M.; Khan, S.A.

    2008-01-01

    To determine the percentage of false positive testing for transfusion transmitted infections (TTIs) using immunochromatographic test (ICT) as first line of screening tests and its effect on loss of volunteer blood donors. Over a period of three months, samples from blood bags of donors undergoing phlebotomy at teaching hospital blood banks in Lahore were screened for human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) by immunochromatographic tests. Those found positive on initial screening were re-tested by ELISA method at the screening laboratory of the Institute of Haematology and Blood Transfusion Service, Punjab. Lahore. Out of a total of 62090 voluntary blood donors, 469 donors were found to be initially reactive for either HIV, HBV or HCV. Amongst these 96 (0.15%) blood donors were found to have tested falsely positive for HIV, HBV or HCV as compared to testing by ELISA. False positive testing rate of 0.15% or 96 out of a total of 62090 donors is rather small in terms of loss of voluntary donors and appropriate utilization of available resources. Although immunochromatographic testing is not the gold standard, however it serves an important purpose of initial donor screening. (author)

  18. Power Production Management of Three Gorges Project

    Institute of Scientific and Technical Information of China (English)

    Zhang Cheng

    2010-01-01

    @@ The Three Gorges Hydropower Plant is the one with the largest installed capacity in the world today and has a decisive and important influence upon the security of the national power grids. It has been operated stably and supplied the East China, Central China, South China,Sichuan and Chongqing with clean renewable energy. This paper presents the management of the project's dispatch, operation and maintenance and puts forward new ideas and new methods for the plant management, which may provide valuable references for the operation of oversized hydropower plants.

  19. Power Production Management of Three Gorges Project

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Three Gorges Hydropower Plant is the one with the largest installed capacity in the world today and has a decisive and important influence upon the security of the national power grids. It has been operated stably and supplied the East China, Central China, South China, Sichuan and Chongqing with clean renewable energy. This paper presents the management of the project’s dispatch, operation and maintenance and puts forward new ideas and new methods for the plant management, which may provide valuable re...

  20. Effective inventory management for nuclear power plants

    International Nuclear Information System (INIS)

    MacFarlane, I.S.

    1985-01-01

    Effective inventory management plays a major role at nuclear power plants toward achieving a high level of availability in a cost-effective manner. It enables maintenance personnel to obtain the correct parts easily, when needed, and in satisfactory condition to perform as intended. In addition, appropriate controls and documentation ensure parts are being used in the correct equipment application. The following elements of inventory management will help achieve plant availability goals: (1) appropriate inventory levels, (2) preapproved procurement requirements, (3) storage maintenance, (4) documentation of parts, and (5) control of computer data base

  1. Advanced water chemistry management in power plants

    International Nuclear Information System (INIS)

    Regis, V.; Sigon, F.

    1995-01-01

    Advanced water management based on low external impact cycle chemistry technologies and processes, effective on-line water control and monitoring, has been verified to improve water utilization and to reduce plant liquid supply and discharge. Simulations have been performed to optimize system configurations and performances, with reference to a 4 x 320 MWe/once-through boiler/AVT/river cooled power plant, to assess the effectiveness of membrane separation technologies allowing waste water reuse, to enhance water management system design and to compare these solutions on a cost/benefit analysis. 6 refs., 3 figs., 3 tabs

  2. Asco 2044 nuclear power plant: management system

    International Nuclear Information System (INIS)

    Ramos Pellejero, J.L.

    2010-01-01

    Due to their complexity and involvement in safety related matters, Nuclear Power Plants have highly reliable management organisations where safety is top priority. To achieve this, there are many elements specific to this type of organisation that are available and which are integrated within a Management System that comprises the necessary measures to ensure and adequate level of safety in the facility, in such a way that it promotes continual improvement, a strengthening of the safety culture and good results in this field. (Author).

  3. Ageing management in German nuclear power plants

    International Nuclear Information System (INIS)

    Becker, D.E.; Reiner, M.

    1998-01-01

    In Germany, the term 'ageing management' comprises several aspects. A demand for a special ageing monitoring programme is not explicitly contained in the regulations. However, from the Atomic Energy Act and its regulations results the operator's obligation to perform extensive measures to maintain the quality of the plant and the operating personnel working in the plant. From this point of view, comprehensive ageing management in German nuclear power plants has taken place right from the start under the generic term of quality assurance. (author)

  4. Active and reactive power support of MV distribution systems using battery energy storage

    DEFF Research Database (Denmark)

    Wang, Jiawei; Hashemi Toghroljerdi, Seyedmostafa; You, Shi

    2017-01-01

    shaving and voltage support service from the perspective of Distribution System Operators (DSOs). An active power support algorithm is implemented and the effects of various load profiles as well as different Photovoltaic (PV) penetration scenarios on the operation of BESS and the optimal BESS converter......Adoption of Battery Energy Storage Systems (BESSs) for provision of grid services is increasing. This paper investigates the applications of BESS for the grid upgrade deferral and voltage support of Medium Voltage (MV) distribution systems. A BESS is modelled in Matlab/Simulink to perform peak load...... size for peak load shaving are investigated. The BESS annual lifetime degradation is also estimated using a rainflow counting algorithm. A reactive power support algorithm embedded with Q-U droop control is proposed in order to reduce the voltage drop in a part of 10 kV distribution network of Nordhavn...

  5. Effects of Radial Reflector Composition on Core Reactivity and Peak Power

    International Nuclear Information System (INIS)

    Park, Sang Yoon; Lee, Kyung Hoon; Song, Jae Seung

    2007-10-01

    The effects of radial SA-240 alloy shroud on core reactivity and peak power are evaluated. The existence of radial SA-240 alloy shroud makes reflector water volume decrease, so the thermal absorption cross section of radial reflector is lower than without SA-240 alloy shroud case. Finally, the cycle length is increased from 788 EFPD to 845 EFPD and the peak power is decreased from 1.66 to 1.49. In the case of without SA-240 alloy shroud, a new core loading pattern search has been performed. For the guarantee of the same equivalent cycle length of with SA-240 alloy shroud case, the enrichment of U-235 should be increased from 4.22 w/o to 4.68 w/o. The nuclear key safety parameters of new core loading pattern have been calculated and recorded for the future

  6. Effects of Radial Reflector Composition on Core Reactivity and Peak Power

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Yoon; Lee, Kyung Hoon; Song, Jae Seung

    2007-10-15

    The effects of radial SA-240 alloy shroud on core reactivity and peak power are evaluated. The existence of radial SA-240 alloy shroud makes reflector water volume decrease, so the thermal absorption cross section of radial reflector is lower than without SA-240 alloy shroud case. Finally, the cycle length is increased from 788 EFPD to 845 EFPD and the peak power is decreased from 1.66 to 1.49. In the case of without SA-240 alloy shroud, a new core loading pattern search has been performed. For the guarantee of the same equivalent cycle length of with SA-240 alloy shroud case, the enrichment of U-235 should be increased from 4.22 w/o to 4.68 w/o. The nuclear key safety parameters of new core loading pattern have been calculated and recorded for the future.

  7. Estimation of power feedback parameters of the IBR-2M reactor by square wave reactivity

    International Nuclear Information System (INIS)

    Pepelyshev, Yu.N.; Popov, A.K.; Sumkhuu, D.

    2016-01-01

    Parameters of the IBR-2M reactor power feedback (PFB) are estimated based on the analysis of power transients caused by deliberate square wave reactivity when the pulsed reactor operates in the self-regulation mode. The PFB of the IBR-2M is described by three linear first-order differential equations. Two components of the PFB are responsible for the negative feedback and one, for the positive. The overall feedback is negative, i.e., it has a stabilizing effect for the operation of the reactor. The slowest negative component of the PFB is probably caused by heating of the fuel. Periodically repeated in the process of exploitation, estimation of the PFB parameters is one of the methods to ensure safety operation of the reactor. [ru

  8. Comparisons of PRD [power-reactivity-decrements] components for various EBR-II configurations

    International Nuclear Information System (INIS)

    Meneghetti, D.; Kucera, D.A.

    1986-01-01

    Comparison of detailed calculations of contributions by region and component of the power-reactivity-decrements (PRD) for four differing loading configurations of the Experimental Breeder Reactor-II (EBR-II) are given. The linear components and Doppler components are calculated. The non-linear (primarily subassembly bowing) components are deduced by differences relative to measured total PRD values. Variations in linear components range from about 10% to as much as about 100% depending upon the component. The deduced non-linear components differ both in magnitude and sign as functions of reactor power. Effects of differing assumptions of the nature of the fuel-to-clad interactions upon the PRD components are also calculated

  9. Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation

    Science.gov (United States)

    Sudhakar, N.; Jain, Siddhartha; Jyotheeswara Reddy, K.

    2017-11-01

    This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.

  10. RF Power Transfer, Energy Harvesting, and Power Management Strategies

    Science.gov (United States)

    Abouzied, Mohamed Ali Mohamed

    Energy harvesting is the way to capture green energy. This can be thought of as a recycling process where energy is converted from one form (here, non-electrical) to another (here, electrical). This is done on the large energy scale as well as low energy scale. The former can enable sustainable operation of facilities, while the latter can have a significant impact on the problems of energy constrained portable applications. Different energy sources can be complementary to one another and combining multiple-source is of great importance. In particular, RF energy harvesting is a natural choice for the portable applications. There are many advantages, such as cordless operation and light-weight. Moreover, the needed infra-structure can possibly be incorporated with wearable and portable devices. RF energy harvesting is an enabling key player for Internet of Things technology. The RF energy harvesting systems consist of external antennas, LC matching networks, RF rectifiers for ac to dc conversion, and sometimes power management. Moreover, combining different energy harvesting sources is essential for robustness and sustainability. Wireless power transfer has recently been applied for battery charging of portable devices. This charging process impacts the daily experience of every human who uses electronic applications. Instead of having many types of cumbersome cords and many different standards while the users are responsible to connect periodically to ac outlets, the new approach is to have the transmitters ready in the near region and can transfer power wirelessly to the devices whenever needed. Wireless power transfer consists of a dc to ac conversion transmitter, coupled inductors between transmitter and receiver, and an ac to dc conversion receiver. Alternative far field operation is still tested for health issues. So, the focus in this study is on near field. The goals of this study are to investigate the possibilities of RF energy harvesting from various

  11. Economic-environmental active and reactive power scheduling of modern distribution systems in presence of wind generations: A distribution market-based approach

    International Nuclear Information System (INIS)

    Samimi, Abouzar; Kazemi, Ahad; Siano, Pierluigi

    2015-01-01

    Highlights: • A new market-based approach is proposed to schedule active and reactive powers. • Multi-component reactive power bidding structures for DERs is introduced. • A new economical/environmental operational scheduling method is proposed. • At distribution level, a reactive power market is developed in presence of DERs. - Abstract: Distribution System Operator (DSO) is responsible for active and reactive power scheduling in a distribution system. DSO purchases its active and reactive power requirements from Distributed Energy Resources (DERs) as well as the wholesale electricity market. In this paper, a new economical/environmental operational scheduling method based on sequential day-ahead active and reactive power markets at distribution level is proposed to dispatch active and reactive powers in distribution systems with high penetration of DERs. In the proposed model, after day-ahead active power market was cleared the participants submit their reactive power bids and then the reactive power market will be settled. At distribution level, developing a Var market, in which DERs like synchronous machine-based Distributed Generation (DG) units and Wind Turbines (WTs) could offer their reactive power prices, DERs are motivated to actively participate in the Volt/VAr Control (VVC) problem. To achieve this purpose, based on the capability curves of considered DERs, innovative multi-component reactive power bidding structures for DERs are introduced. Moreover, the effect of reactive power market clearing on the active power scheduling is explicitly considered into the proposed model by rescheduling of active power by usage of energy-balance service bids. On the other hand, environmental concerns that arise from the operation of fossil fuel fired electric generators are included in the proposed model by employing CO_2 emission penalty cost. The suggested reactive power market is cleared through a mixed-integer nonlinear optimization program. The

  12. [Karachi Nuclear Power Plant (KANUPP), Safety Management

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, S M [Karachi Nuclear Power Plant (KANUPP), Karachi (Pakistan)

    1997-12-01

    The present regime for CANDU safety management in Pakistan has evolved in line with contemporary international practice, and is essential adequate to ensure the continued safety of KANUPP and other future CANDU reactors, as confirmed by international reviews as well. But the small size of Pakistan nuclear power program poses limitations in developing - expert judgment in analysis of in-service inspection data; and own methodology for CANDU safety analysis.

  13. Life cycle management at Ontario Power Generation

    International Nuclear Information System (INIS)

    Spekkens, P.

    2006-01-01

    This paper outlines the Life Cycle Management (LCM) program at Ontario Power Generation. LCM is carried out at different levels that includes components, systems, unit and fleet. A system involves cumulative effect of individual component aging. These components include steam generators, pressure tubes and feeders. A unit involves an overall unit aging strategy integrating all systems. At the fleet level, there is an optimal strategy for plant-level investments including end-of-life of a unit

  14. [Karachi Nuclear Power Plant (KANUPP), Safety Management

    International Nuclear Information System (INIS)

    Hasan, S.M.

    1997-01-01

    The present regime for CANDU safety management in Pakistan has evolved in line with contemporary international practice, and is essential adequate to ensure the continued safety of KANUPP and other future CANDU reactors, as confirmed by international reviews as well. But the small size of Pakistan nuclear power program poses limitations in developing - expert judgment in analysis of in-service inspection data; and own methodology for CANDU safety analysis

  15. Automation technology for aerospace power management

    Science.gov (United States)

    Larsen, R. L.

    1982-01-01

    The growing size and complexity of spacecraft power systems coupled with limited space/ground communications necessitate increasingly automated onboard control systems. Research in computer science, particularly artificial intelligence has developed methods and techniques for constructing man-machine systems with problem-solving expertise in limited domains which may contribute to the automation of power systems. Since these systems perform tasks which are typically performed by human experts they have become known as Expert Systems. A review of the current state of the art in expert systems technology is presented, and potential applications in power systems management are considered. It is concluded that expert systems appear to have significant potential for improving the productivity of operations personnel in aerospace applications, and in automating the control of many aerospace systems.

  16. Inherent Safety Feature of Hybrid Low Power Research Reactor during Reactivity Induced Accident

    Energy Technology Data Exchange (ETDEWEB)

    Kim, DongHyun; Yum, Soo Been; Hong, Sung Teak; Lim, In-Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Hybrid low power research reactor(H-LPRR) is the new design concept of low power research reactor for critical facility as well as education and training. In the case of typical low power research reactor, the purposes of utilization are the experiments for education of nuclear engineering students, Neutron Activation Analysis(NAA) and radio-isotope production for research purpose. H-LPRR is a light-water cooled and moderated research reactor that uses rod-type LEU UO{sub 2} fuels same as those for commercial power plants. The maximum core thermal power is 70kW and, the core is placed in the bottom of open pool. There are 1 control rod and 2 shutdown rods in the core. It is designed to cool the core by natural convection, retain negative feedback coefficient for entire fuel periods and operate for 20 years without refueling. Inherent safety in H-LPRR is achieved by passive design features such as negative temperature feedback coefficient and core cooling by natural convection during normal and emergency conditions. The purpose of this study is to find out that the inherent safety characteristics of H-LPRR is able to control the power and protect the reactor from the RIA(Reactivity induced accident). RIA analysis was performed to investigate the inherent safety feature of H-LPRR. As a result, it was found that the reactor controls its power without fuel damage in the event and that the reactor remains safe states inherently. Therefore, it is believed that high degree of safety inheres in H-LPRR.

  17. Managing nuclear waste from power plants

    International Nuclear Information System (INIS)

    Keeney, R.L.; Winterfeldt, D. von

    1994-01-01

    National strategies to manage nuclear waste from commercial nuclear power plants are analyzed and compared. The current strategy is to try to operate a repository at Yucca Mountain, Nevada, to dispose storage at a centralized facility or next to nuclear power plants. If either of these is pursued now, the analysis assumes that a repository will be built in 2100 for waste not subsequently put to use. The analysis treats various uncertainties: whether a repository at Yucca Mountain would be licensed, possible theft and misuse of the waste, innovations in repository design and waste management, the potential availability of a cancer cure by 2100, and possible future uses of nuclear waste. The objectives used to compare alternatives include concerns for health and safety, environmental and socioeconomic impacts, and direct economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs to electricity ratepayers, federal government responsibility to manage nuclear waste, and implications of theft and misuse of nuclear waste. The analysis shows that currently building an underground repository at Yucca Mountain is inferior to other available strategies by the equivalent of $10,000 million to $50,000 million. This strongly suggests that this policy should be reconsidered. A more detailed analysis using the framework presented would help to define a new national policy to manage nuclear waste. 36 refs., 3 figs., 17 tabs

  18. Management of nuclear power plants lifetime

    International Nuclear Information System (INIS)

    Hutin, J.P.

    2006-01-01

    The factors influencing the management of the service life of nuclear power plants can be of various types and the 'heaviest' ones have to be managed through robust and explicit approaches involving all actors. However, the mastery of the service life starts with the mastery of the technical problems, in particular the physical aging of the facilities. This mastery requires to foresee and anticipate the problems and thus a good understanding of the phenomena involved. This article presents: 1 - the general problem of service life management: lifetime concept, situation of French power plants, service life management policy; 2 - aging mechanisms: embrittlement of steel under irradiation, swelling of materials, thermal aging, fatigue, stress corrosion, aqueous corrosion of metals, corrosion-erosion, mechanisms of concrete degradation, mechanisms of elastomers and polymers degradation, wear; 3 - non-replaceable parts: reactor vessel, containment building; 4 - replaceable parts: cables, instrumentation and control system, core internals, primary loop piping, auxiliary primary piping, pressurizer, primary pump, steam generator tubes, other Ni-Cr-Fe alloy parts, secondary loop piping, turbine, alternator; 5 - non-technical aspects: perenniality of the industrial support, evolution of safety requirements, public acceptance, economical aspects, knowledge and information systems; 6 - situation in foreign countries: status of the world nuclear park, lifetime notion in foreign countries, situation in the USA. (J.S.)

  19. 78 FR 63177 - Order on Voluntary Remand and Clarifying Policy on Filing of Reactive Power Service Rate...

    Science.gov (United States)

    2013-10-23

    ... the obligation to follow a voltage schedule.'' \\19\\ The Commission distinguished Hot Spring Power Co..., to explore the mechanics of public utilities filing reactive power rate schedules for which there is...'' jurisdictional service and, accordingly, must be filed for Commission review); Sulphur Springs Valley Elec. Coop...

  20. Project management skills for nuclear power plants

    International Nuclear Information System (INIS)

    Bhatikar, R.J.

    2002-01-01

    Full text: The E and C Division of L and T has executed several power projects in India and abroad and thus possesses the requisite wherewithal to execute nuclear power projects on a fast track basis. To achieve this L and T has set up a separate Strategic Business Unit (SBU) to have a focused attention to the nuclear power industry in the country. All the four important and necessary hallmarks for successful implementation of any project namely (i) engineering capabilities, (ii) sophisticated project management tools, (iii) ability to mobilize resources, and (iv) skilled personnel to execute the project have been adequately addressed. These could be realized either by establishing fruitful collaborations with other specialist Companies and/or creating powerful and multitasking software tools for effective implementation. The execution of nuclear power projects on a fast track basis could be implemented by following the EPC route and by minimizing the number of packages. Details of this scheme for project implementation will be highlighted during the talk

  1. Preliminary study on the reactivation of the WERAP small hydro power station in Bubikon

    International Nuclear Information System (INIS)

    Bretscher, A.; Gutzwiller, S.

    2003-01-01

    This study on the revitalisation of a small hydro power station belonging to old spinning mill in Bubikon, Switzerland, proposes ideas for the reactivation of an old hydropower installation that once helped power a spinning mill. Details are given on the history of the mill and the hydrological conditions to be expected at the site. Three variants are proposed for the refurbishment, including the revision of the power station's existing 44 kW Francis turbine dating from 1908, the addition of further, similar Francis turbine or its replacement with a new 61 kW Francis turbine. The costs and amortisation of the refurbishment variants are examined, the revenues that can be expected from its operation and other financial factors are discussed. Further, environmental and legal aspects of the project are examined and suggestions are made for the next steps to be taken towards the realisation of this small hydropower plant. An annex provides photographs of the location and the power station's equipment

  2. Fuzzy-TLBO optimal reactive power control variables planning for energy loss minimization

    International Nuclear Information System (INIS)

    Moghadam, Ahmad; Seifi, Ali Reza

    2014-01-01

    Highlights: • A new approach to the problem of optimal reactive power control variables planning is proposed. • The energy loss minimization problem has been formulated by modeling the load of system as a Load Duration Curve. • To solving the energy loss problem, the classic methods and the evolutionary methods are used. • A new proposed fuzzy teaching–learning based algorithm is applied to energy loss problem. • Simulations are done to show the effectiveness and superiority of the proposed algorithm compared with other methods. - Abstract: This paper offers a new approach to the problem of optimal reactive power control variables planning (ORPVCP). The basic idea is division of Load Duration Curve (LDC) into several time intervals with constant active power demand in each interval and then solving the energy loss minimization (ELM) problem to obtain an optimal initial set of control variables of the system so that is valid for all time intervals and can be used as an initial operating condition of the system. In this paper, the ELM problem has been solved by the linear programming (LP) and fuzzy linear programming (Fuzzy-LP) and evolutionary algorithms i.e. MHBMO and TLBO and the results are compared with the proposed Fuzzy-TLBO method. In the proposed method both objective function and constraints are evaluated by membership functions. The inequality constraints are embedded into the fitness function by the membership function of the fuzzy decision and the problem is modeled by fuzzy set theory. The proposed Fuzzy-TLBO method is performed on the IEEE 30 bus test system by considering two different LDC; and it is shown that using this method has further minimized objective function than original TLBO and other optimization techniques and confirms its potential to solve the ORPCVP problem with considering ELM as the objective function

  3. A Fast Reactive Power Optimization in Distribution Network Based on Large Random Matrix Theory and Data Analysis

    Directory of Open Access Journals (Sweden)

    Wanxing Sheng

    2016-05-01

    Full Text Available In this paper, a reactive power optimization method based on historical data is investigated to solve the dynamic reactive power optimization problem in distribution network. In order to reflect the variation of loads, network loads are represented in a form of random matrix. Load similarity (LS is defined to measure the degree of similarity between the loads in different days and the calculation method of the load similarity of load random matrix (LRM is presented. By calculating the load similarity between the forecasting random matrix and the random matrix of historical load, the historical reactive power optimization dispatching scheme that most matches the forecasting load can be found for reactive power control usage. The differences of daily load curves between working days and weekends in different seasons are considered in the proposed method. The proposed method is tested on a standard 14 nodes distribution network with three different types of load. The computational result demonstrates that the proposed method for reactive power optimization is fast, feasible and effective in distribution network.

  4. High efficiency H6 single-phase transformerless grid-tied PV inverter with proposed modulation for reactive power generation

    Science.gov (United States)

    Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

    2017-08-01

    Implementation of transformerless inverters in PV grid-tied system offer great benefits such as high efficiency, light weight, low cost, etc. Most of the proposed transformerless inverters in literature are verified for only real power application. Currently, international standards such as VDE-AR-N 4105 has demanded that PV grid-tied inverters should have the ability of controlling a specific amount of reactive power. Generation of reactive power cannot be accomplished in single phase transformerless inverter topologies because the existing modulation techniques are not adopted for a freewheeling path in the negative power region. This paper enhances a previous high efficiency proposed H6 trnasformerless inverter with SiC MOSFETs and demonstrates new operating modes for the generation of reactive power. A proposed pulse width modulation (PWM) technique is applied to achieve bidirectional current flow through freewheeling state. A comparison of the proposed H6 transformerless inverter using SiC MOSFETs and Si MOSFTEs is presented in terms of power losses and efficiency. The results show that reactive power control is attained without adding any additional active devices or modification to the inverter structure. Also, the proposed modulation maintains a constant common mode voltage (CM) during every operating mode and has low leakage current. The performance of the proposed system verifies its effectiveness in the next generation PV system.

  5. Intelligent power system data management systems (DBMS)

    Energy Technology Data Exchange (ETDEWEB)

    Middleton, A.; Macdonald, E. [GE Digital Energy, Markham, ON (Canada); Schreiner, Z. [Intelligent Process Solutions GmbH, Lindau (Germany); Bizjak, J. [Elektro Ljubljana d.d., Ljubljana (Slovenia)

    2010-07-01

    Network owners/operators from around the world have moved from electromechanical products to intelligent electronic devices (IEDs). Most networks have a multi-generation technology mix because protection assets have a normal application lifespan of between 10 and 40 years. Associated data capture and maintenance management regimes have therefore moved from paper based into digitized media, creating a significant increase in the volume of acquired data, such that there is now a mix of paper and digitized storage. Data is rarely consolidated or used for decision making in asset management processes once testing is completed, having a major impact on overall power system reliability. This paper presented the concept of intelligent operative maintenance management, now becoming more recognized in the industry. The concept was described as the management of operational data, resulting actions and responses, wherever and by whoever they are needed, without any additional overhead. The paper discussed new techniques of testing as well as planning and operative maintenance. The practical benefits of the new system were also presented, with particular reference to central management; simplification of routine protocols; secondary testing; and reduced cost of data handling. It was concluded that the main benefit from all of the techniques discussed in this paper is that experienced expert test engineers can focus more time upon making good, critical decisions to ensure that utilities maximize their customer service and safety regimes. 13 refs., 7 figs.

  6. Management of delayed nuclear power plant projects

    International Nuclear Information System (INIS)

    2005-01-01

    The IAEA assists the management of organizations responsible for Nuclear Power Plant Projects with significant delays with respect to the originally scheduled commercial operation. Several Member States have Nuclear Power Plant Projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules shows large variations due to several issues, including financial, economic and public opinion factors. Solving the special difficulties related with a delayed NPP project is problematic and dependent on the particular country situation. However it is not regarded as an isolated national problem but as a significant issue with a number of difficulties shared by several Member States. The IAEA collects information and supports the management of delayed NPP projects by identifying main common issues, gathering available experience and addressing specific needs. On this background the IAEA is in the position to provide unique impartial assistance based upon best international practices. This enables Member States to maintain readiness for resuming the project construction when the conditions permit and to strengthen management's abilities for the completion of the project. The IAEA's service is tailored to the needs and requirements of the requesting organization, implemented on-site by international experts and addresses areas such as project control measures, human resources, updating to technological and regulatory requirements, project data, nuclear safety review, physical protection and nuclear security and preparation to resume project construction and operation

  7. Raptor nest management on power lines

    Energy Technology Data Exchange (ETDEWEB)

    Harness, R.E. [EDM International Inc., Fort Collins, CO (United States)

    2005-07-01

    Many utilities in South Africa are now implementing labor-intensive methods to combat raptor nesting on power transmission lines. Methods have typically included direct nest removal and trimming of nest materials. However, the process is often unsuccessful, and utilities are now learning to accommodate the raptor nests. This paper argued that managing nests on utility structures has solved many operational problems and has resulted in positive publicity for many line operators. Nest management options included the use of stick deflectors to prevent nest material from accumulating during initial nest construction, as well as encouraging raptors to shift their efforts to a more suitable location. Raptors will often accept alternative nesting platforms, and taller, surrogate nesting poles can be placed next to distribution line structures. Elevated platforms can also be placed on problematic distribution structures, but may result in birds coming into contact with unprotected equipment. It was concluded that a successful nest management program includes plans to make nearby lines safe for raptors and to prevent their electrocution. Providing nests with bird-friendly utility configurations can result in electric facilities enhancing wild raptor populations without impacting power reliability. 14 refs., 9 figs.

  8. Mitigating Space Weather Impacts on the Power Grid in Real-Time: Applying 3-D EarthScope Magnetotelluric Data to Forecasting Reactive Power Loss in Power Transformers

    Science.gov (United States)

    Schultz, A.; Bonner, L. R., IV

    2017-12-01

    Current efforts to assess risk to the power grid from geomagnetic disturbances (GMDs) that result in geomagnetically induced currents (GICs) seek to identify potential "hotspots," based on statistical models of GMD storm scenarios and power distribution grounding models that assume that the electrical conductivity of the Earth's crust and mantle varies only with depth. The NSF-supported EarthScope Magnetotelluric (MT) Program operated by Oregon State University has mapped 3-D ground electrical conductivity structure across more than half of the continental US. MT data, the naturally occurring time variations in the Earth's vector electric and magnetic fields at ground level, are used to determine the MT impedance tensor for each site (the ratio of horizontal vector electric and magnetic fields at ground level expressed as a complex-valued frequency domain quantity). The impedance provides information on the 3-D electrical conductivity structure of the Earth's crust and mantle. We demonstrate that use of 3-D ground conductivity information significantly improves the fidelity of GIC predictions over existing 1-D approaches. We project real-time magnetic field data streams from US Geological Survey magnetic observatories into a set of linear filters that employ the impedance data and that generate estimates of ground level electric fields at the locations of MT stations. The resulting ground electric fields are projected to and integrated along the path of power transmission lines. This serves as inputs to power flow models that represent the power transmission grid, yielding a time-varying set of quasi-real-time estimates of reactive power loss at the power transformers that are critical infrastructure for power distribution. We demonstrate that peak reactive power loss and hence peak risk for transformer damage from GICs does not necessarily occur during peak GMD storm times, but rather depends on the time-evolution of the polarization of the GMD's inducing fields

  9. Credit risk management in the power sector

    International Nuclear Information System (INIS)

    Allen, D.

    2002-01-01

    Deregulation of the electric power industry has the potential to put power businesses at market risk particularly when the value of an asset or liability will change with market movements. Market risk gives rise to credit risk where a contract cannot be fulfilled. This presentation describes how credit risks can be identified and measured. Most practitioners use some variant of value-at-risk (VAR) technology for measuring market risk. Under this approach, risk is determined by the volatility implied by the market. Volatility of electricity prices and natural gas prices has increased significantly in Alberta in recent years. The consequence is an increase in both market and credit risk. The author described the difference between the two risks and their significance. An overview of credit risk management with derivatives, an over-the counter contract, was also presented. The author also discusses issue of protection buyers in the event of a failed contract. 9 figs

  10. An Optimal Reactive Power Control Strategy for a DFIG-Based Wind Farm to Damp the Sub-Synchronous Oscillation of a Power System

    Directory of Open Access Journals (Sweden)

    Bin Zhao

    2014-05-01

    Full Text Available This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capacitive compensation transmission system. First, the damping effect of the reactive power control of the DFIG-based wind farms was theoretically analyzed, and a transfer function between turbogenerator speed and the output reactive power of the wind farms was introduced to derive the analytical expression of the damping coefficient. The phase range to obtain positive damping was determined. Second, the PID phase compensation parameters of the auxiliary damping controller were optimized by a genetic algorithm to obtain the optimum damping in the entire subsynchronous frequency band. Finally, the validity and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory. Theoretical analysis and simulation results show that this derived damping factor expression and the condition of the positive damping can effectively analyze their impact on the system sub-synchronous oscillations, the proposed wind farms reactive power additional damping control strategy can provide the optimal damping effect over the whole sub-synchronous frequency band, and the control effect is better than the active power additional damping control strategy based on the power system stabilizator.

  11. New Enhanced Artificial Bee Colony (JA-ABC5 Algorithm with Application for Reactive Power Optimization

    Directory of Open Access Journals (Sweden)

    Noorazliza Sulaiman

    2015-01-01

    Full Text Available The standard artificial bee colony (ABC algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement.

  12. New enhanced artificial bee colony (JA-ABC5) algorithm with application for reactive power optimization.

    Science.gov (United States)

    Sulaiman, Noorazliza; Mohamad-Saleh, Junita; Abro, Abdul Ghani

    2015-01-01

    The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement.

  13. Performance management for nuclear power plant operators

    International Nuclear Information System (INIS)

    Fan Pengfei

    2014-01-01

    Fuel was loaded to Unit 3 of the second power plant in May 2010. The Second Operation Division stepped in the operation stage from production preparation and commissioning and exploration of performance management was started. By means of performance evaluation, a closed loop of performance management was formed, staff enthusiasm improved, and potential capability inspired through evaluation, analysis and improvement. The performance evaluation covers attitude, skill, efficiency, performance, teamwork sense, cooperation, etc. Quantitative appraisal was carried out through 31 objective indicators of the working process and results. According to the evaluation results and personal interviews, indicators were modified. Through the performance evaluation, positive guidance is provided to the employees to promote the development of employees, departments and the enterprise. (authors)

  14. Comprehensive Cost Minimization in Distribution Networks Using Segmented-time Feeder Reconfiguration and Reactive Power Control of Distributed Generators

    DEFF Research Database (Denmark)

    Chen, Shuheng; Hu, Weihao; Chen, Zhe

    2016-01-01

    In this paper, an efficient methodology is proposed to deal with segmented-time reconfiguration problem of distribution networks coupled with segmented-time reactive power control of distributed generators. The target is to find the optimal dispatching schedule of all controllable switches...... and distributed generators’ reactive powers in order to minimize comprehensive cost. Corresponding constraints, including voltage profile, maximum allowable daily switching operation numbers (MADSON), reactive power limits, and so on, are considered. The strategy of grouping branches is used to simplify...... (FAHPSO) is implemented in VC++ 6.0 program language. A modified version of the typical 70-node distribution network and several real distribution networks are used to test the performance of the proposed method. Numerical results show that the proposed methodology is an efficient method for comprehensive...

  15. In-core fuel management for the course on operational physics of power reactors

    International Nuclear Information System (INIS)

    Levine, S.H.

    1982-01-01

    The heart of a nuclear power station is the reactor core producing power from the fissioning of uranium or plutonium fuel. Expertise in many different technical fields is required to provide fuel for continuous economical operation of a nuclear power plant. In general, these various technical disciplines can be dichotomized into ''Out-of-core'' and ''In-core'' fuel management. In-core fuel management is concerned, as the name implies, with the reactor core itself. It entails calculating the core reactivity, power distribution, and isotopic inventory for the first and subsequent cores of a nuclear power plant to maintain adequate safety margins and operating lifetime for each core. In addition, the selection of reloading schemes is made to minimize energy costs

  16. Dependence of RF power on the content and configuration of hydrogen in amorphous hydrogenated silicon by reactive sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Imura, T; Ushita, K; Mogi, K; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering

    1981-06-01

    Infrared absorption spectra at stretching bands of Si-H were investigated in hydrogenated amorphous silicon fabricated by reactive sputtering in the atmosphere of Ar and H/sub 2/ (10 mole%) at various input rf powers in the range from 0.8 to 3.8 W/cm/sup 2/. Hydrogen content mainly due to the configuration of Si=H/sub 2/ in the film increased with the decreasing rf power, as the deposition rate was decreased. On the other hand, the quantity of the monohydride (Si-H) configuration depended less on the power. Attachment of hydrogen molecules onto the fresh and reactive surface of silicon deposited successively was proposed for possible process of hydrogen incusion into amorphous silicon resulting in Si=H/sub 2/ configuration. The photoconductivity increased as the input power became higher, when the deposition rate also increased linearly with the power.

  17. Power generation operations management : due diligence

    International Nuclear Information System (INIS)

    Hill, D.; Paul, G.

    1998-01-01

    The practical applications of an emergency planning process within Edmonton Power's power generation operations management were discussed. A project was initiated to develop a corporate emergency planning standard which incorporates existing emergency procedures into a unified management system. The need for an emergency planning standard which would establish planning criteria became evident after a tornado hit Edmonton on July 31, 1987, killing 27 and causing $330 million in damages. The emergency plans in effect at the time were less than adequate. The components of the new emergency planning standards include: (1) policy and hazard analysis, (2) functional responsibilities, (3) initial response, (4) emergency support, (5) mutual aid, (6) business protection and recovery, (7) emergency response debriefing, (8) training and exercises, and (9) emergency plan distribution and maintenance. A brief summary of the intent of each section, and some of the experiences learned during the development of this emergency plan are described for the benefit of those who may be called upon to develop an integrated emergency plan in the future. 1 ref

  18. Managing Siting Activities for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  19. Managing Siting Activities for Nuclear Power Plants

    International Nuclear Information System (INIS)

    2012-01-01

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  20. Sustainable promotion nuclear power enterprise procurement bidding risk management

    International Nuclear Information System (INIS)

    Wu Yimin

    2014-01-01

    Nuclear power enterprise procurement bidding work faced with certain risk in recent years, the domestic nuclear power enterprises in the bidding work never stop research and explore the effective ways to guard against legal risks, and has made considerable progress, the eighteenth big country advocates the safety and efficiency of nuclear power development policy, in the face of the subsequent nuclear power construction projects have started, nuclear power enterprise bidding risk management work shoulder heavy responsibilities article through nuclear power enterprise procurement bidding risk management present situation, proposed the sustainable promotion nuclear power enterprise procurement bidding risk management countermeasures. (author)

  1. Nuclear power plant reliability database management

    International Nuclear Information System (INIS)

    Meslin, Th.; Aufort, P.

    1996-04-01

    In the framework of the development of a probabilistic safety project on site (notion of living PSA), Saint Laurent des Eaux NPP implements a specific EDF reliability database. The main goals of this project at Saint Laurent des Eaux are: to expand risk analysis and to constitute an effective local basis of thinking about operating safety by requiring the participation of all departments of a power plant: analysis of all potential operating transients, unavailability consequences... that means to go further than a simple culture of applying operating rules; to involve nuclear power plant operators in experience feedback and its analysis, especially by following up behaviour of components and of safety functions; to allow plant safety managers to outline their decisions facing safety authorities for notwithstanding, preventive maintenance programme, operating incident evaluation. To hit these goals requires feedback data, tools, techniques and development of skills. The first step is to obtain specific reliability data on the site. Raw data come from plant maintenance management system which processes all maintenance activities and keeps in memory all the records of component failures and maintenance activities. Plant specific reliability data are estimated with a Bayesian model which combines these validated raw data with corporate generic data. This approach allow to provide reliability data for main components modelled in PSA, to check the consistency of the maintenance program (RCM), to verify hypothesis made at the design about component reliability. A number of studies, related to components reliability as well as decision making process of specific incident risk evaluation have been carried out. This paper provides also an overview of the process management set up on site from raw database to specific reliability database in compliance with established corporate objectives. (authors). 4 figs

  2. Nuclear power plant reliability database management

    Energy Technology Data Exchange (ETDEWEB)

    Meslin, Th [Electricite de France (EDF), 41 - Saint-Laurent-des-Eaux (France); Aufort, P

    1996-04-01

    In the framework of the development of a probabilistic safety project on site (notion of living PSA), Saint Laurent des Eaux NPP implements a specific EDF reliability database. The main goals of this project at Saint Laurent des Eaux are: to expand risk analysis and to constitute an effective local basis of thinking about operating safety by requiring the participation of all departments of a power plant: analysis of all potential operating transients, unavailability consequences... that means to go further than a simple culture of applying operating rules; to involve nuclear power plant operators in experience feedback and its analysis, especially by following up behaviour of components and of safety functions; to allow plant safety managers to outline their decisions facing safety authorities for notwithstanding, preventive maintenance programme, operating incident evaluation. To hit these goals requires feedback data, tools, techniques and development of skills. The first step is to obtain specific reliability data on the site. Raw data come from plant maintenance management system which processes all maintenance activities and keeps in memory all the records of component failures and maintenance activities. Plant specific reliability data are estimated with a Bayesian model which combines these validated raw data with corporate generic data. This approach allow to provide reliability data for main components modelled in PSA, to check the consistency of the maintenance program (RCM), to verify hypothesis made at the design about component reliability. A number of studies, related to components reliability as well as decision making process of specific incident risk evaluation have been carried out. This paper provides also an overview of the process management set up on site from raw database to specific reliability database in compliance with established corporate objectives. (authors). 4 figs.

  3. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  4. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments.

    Directory of Open Access Journals (Sweden)

    Qaisar Ayub

    Full Text Available Delay Tolerant Network (DTN multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio.

  5. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments.

    Science.gov (United States)

    Ayub, Qaisar; Ngadi, Asri; Rashid, Sulma; Habib, Hafiz Adnan

    2018-01-01

    Delay Tolerant Network (DTN) multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl) parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl) is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R) for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio.

  6. Appraisals and impression management opportunities: person and situation influences on cardiovascular reactivity.

    Science.gov (United States)

    Heffner, Kathi L; Ginsburg, G P; Hartley, Terry R

    2002-05-01

    This study examined how threat and coping appraisals and impression management opportunities influenced cardiovascular reactivity within a self-presentation context. Participants were videotaped performing a speech that they believed might be evaluated. Participants' physiological responses were recorded 1 week later while: (a) watching their speech, indicating which portions they wished to re-shoot before it was evaluated,;(b) simply watching their speech; or (c) watching an architectural videotape and indicating which portions should be reshot, and also watching their own speech, but without evaluation concerns. Cardiovascular reactivity was influenced by the presence or absence of the impression management opportunity, but more variance in reactivity was explained when participants' threat and coping appraisals were also taken into account. The specific cardiovascular responses pertinent to goal-relevant action within each condition were the only responses related to appraisals. These findings emphasize the importance of considering both the situation and the state of the individual in that situation when attempting to understand social psychological influences on physiological reactivity.

  7. Solving multiobjective optimal reactive power dispatch using modified NSGA-II

    Energy Technology Data Exchange (ETDEWEB)

    Jeyadevi, S.; Baskar, S.; Babulal, C.K.; Willjuice Iruthayarajan, M. [Department of Electrical and Electronics Engineering, Thiagarajar College of Engineering, Madurai, Tamilnadu 625 015 (India)

    2011-02-15

    This paper addresses an application of modified NSGA-II (MNSGA-II) by incorporating controlled elitism and dynamic crowding distance (DCD) strategies in NSGA-II to multiobjective optimal reactive power dispatch (ORPD) problem by minimizing real power loss and maximizing the system voltage stability. To validate the Pareto-front obtained using MNSGA-II, reference Pareto-front is generated using multiple runs of single objective optimization with weighted sum of objectives. For simulation purposes, IEEE 30 and IEEE 118 bus test systems are considered. The performance of MNSGA-II, NSGA-II and multiobjective particle swarm optimization (MOPSO) approaches are compared with respect to multiobjective performance measures. TOPSIS technique is applied on obtained non-dominated solutions to determine best compromise solution (BCS). Karush-Kuhn-Tucker (KKT) conditions are also applied on the obtained non-dominated solutions to substantiate a claim on optimality. Simulation results are quite promising and the MNSGA-II performs better than NSGA-II in maintaining diversity and authenticates its potential to solve multiobjective ORPD effectively. (author)

  8. Real And Reactive Power Saving In Three Phase Induction Machine Using Star-Delta Switching Schemes

    Directory of Open Access Journals (Sweden)

    Ramesh Daravath

    2017-04-01

    Full Text Available Induction machines are the most commonly used industrial drives for variety of applications. It has been estimated that induction motors consumes approximately 50 of all the electric energy generated. Further in the area of renewable energy sources such as wind or bio-mass energy induction machines have been found suitable for functioning as generators. In this context it may be mentioned that a star-delta switching is common for the starting of three-phase induction motor. Now it is proposed to use this star-delta switching for energy conservation of induction machines i.e. at times of reduced loads the machine switched back to star connection. Using a three-phase 400 V 50 Hz 4-pole induction machine it has been demonstrated that the star-delta switching of stator winding of three-phase induction machine motor generator operations reconnected in star at suitable reduced loads with a switching arrangement can result in improved efficiency and power factor as compared to a fixed delta or star connection. The predetermined values along with the experimental results have also been presented in this report. A simulation program has been developed for the predetermination of performance of the three-phase induction machine using exact equivalent circuit. A case study on a 250 kW 400 V 4-pole three-phase induction machine operated with different load cycles reveals the significant real and reactive power savings that could be obtained in the present proposal.

  9. National supply of reactivity control rods for Embalse nuclear power plant (CNE)

    International Nuclear Information System (INIS)

    Biondo, C.D.; Carloni, J.G.; Aba, J.A.

    1987-01-01

    The manufacture and supply on industrial scale of reactivity control rods for CNE (Embalse nuclear power plant) were developed by the National Atomic Energy Commission (CNEA) together with the private industry, as part of a program aimed to the substitution of imported supplies used in the operation of power plants by materials manufactured in Argentina. So far, the control rods were imported from Canada. In this work, the different development stages performed by CNEA and CONUAR S.A. are described, leading to the supply of a set of 21 cobalt rods to be included in a reactor of CNE in order to qualify this component. Among the main activities performed, the following stand out: specifications development, particularly those concerning to cobalt cores, evaluation of design documentation and elaboration of bidding conditions and a plan of manufacture and control. According to the results obtained during the service and the post-irradiation measurements, the design will be reviewed in order to undertake new manufacturing plans. (Author)

  10. Thermal Performance and Reliability Analysis of Single-Phase PV Inverters with Reactive Power Injection Outside Feed-In Operating Hours

    DEFF Research Database (Denmark)

    Anurag, Anup; Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    Reactive power support by photovoltaic (PV) systems is of increasingly interest, when compared to the conventional reactive power compensation devices. PV inverters can exchange reactive power with the utility grid in a decentralized manner even outside feed-in operation, especially at nights when...... there is no solar irradiance. However, reactive power injection causes additional power losses in the switching components leading to a temperature rise in the devices. Thus, this paper analyses the impact of reactive power injection by PV inverters outside feed-in operation on the thermal performance...... of their power switching components. A thermal analysis based on the mission profile (i.e., solar irradiance and ambient temperature) has been incorporated, so as to determine the additional temperature rise in the components induced by the operation outside feed-in hours. An analytical lifetime model has been...

  11. Optimal stochastic reactive power scheduling in a microgrid considering voltage droop scheme of DGs and uncertainty of wind farms

    International Nuclear Information System (INIS)

    Khorramdel, Benyamin; Raoofat, Mahdi

    2012-01-01

    Distributed Generators (DGs) in a microgrid may operate in three different reactive power control strategies, including PV, PQ and voltage droop schemes. This paper proposes a new stochastic programming approach for reactive power scheduling of a microgrid, considering the uncertainty of wind farms. The proposed algorithm firstly finds the expected optimal operating point of each DG in V-Q plane while the wind speed is a probabilistic variable. A multi-objective function with goals of loss minimization, reactive power reserve maximization and voltage security margin maximization is optimized using a four-stage multi-objective nonlinear programming. Then, using Monte Carlo simulation enhanced by scenario reduction technique, the proposed algorithm simulates actual condition and finds optimal operating strategy of DGs. Also, if any DGs are scheduled to operate in voltage droop scheme, the optimum droop is determined. Also, in the second part of the research, to enhance the optimality of the results, PSO algorithm is used for the multi-objective optimization problem. Numerical examples on IEEE 34-bus test system including two wind turbines are studied. The results show the benefits of voltage droop scheme for mitigating the impacts of the uncertainty of wind. Also, the results show preference of PSO method in the proposed approach. -- Highlights: ► Reactive power scheduling in a microgrid considering loss and voltage security. ► Stochastic nature of wind farms affects reactive power scheduling and is considered. ► Advantages of using the voltage droop characteristics of DGs in voltage security are shown. ► Power loss, voltage security and VAR reserve are three goals of a multi-objective optimization. ► Monte Carlo method with scenario reduction is used to determine optimal control strategy of DGs.

  12. Managing nuclear power stations for success

    International Nuclear Information System (INIS)

    Smith, G.

    2006-01-01

    Ontario Power Generation's (OPG) top operational priority is to manage its nuclear assets to ensure they operate as safely, efficiently and cost effectively as possible. In meeting these objectives, the company is focused on continuously improving its nuclear performance and benchmarking that performance against the best in North America. This presentation explores how OPG is improving its nuclear performance and the steps it is taking to sustain performance success going forward. Topics to be discussed include the measures OPG is taking to enhance human performance and station reliability as well as the company's preparations to determine if a business case exists for extending the lives of the Pickering B and eventually the Darlington nuclear stations. (author)

  13. Galileo spacecraft power management and distribution system

    International Nuclear Information System (INIS)

    Detwiler, R.C.; Smith, R.L.

    1990-01-01

    It has been twelve years since two Voyager spacecraft began the direct route to the outer planets. In October 1989 a single Galileo spacecraft started the return to Jupiter. Conceived as a simple Voyager look-alike, the Galileo power management and distribution (PMAD) system has undergone many iterations in configuration. Major changes to the PMAD resulted from dual spun slip ring limitations, variations in launch vehicle thrust capabilities, and launch delays. Lack of an adequate launch vehicle for an interplanetary mission of Galileo's size has resulted in an extremely long flight duration. A Venus-Earth-Earth Gravity Assist (VEEGA) tour, vital to attain the required energy, results in a 6 year trip to Jupiter and its moons. This paper provides a description of the Galileo PMAD and documents the design drivers that established the final as-built hardware

  14. Configuration management in nuclear power plants

    CERN Document Server

    2003-01-01

    Configuration management (CM) is the process of identifying and documenting the characteristics of a facility's structures, systems and components of a facility, and of ensuring that changes to these characteristics are properly developed, assessed, approved, issued, implemented, verified, recorded and incorporated into the facility documentation. The need for a CM system is a result of the long term operation of any nuclear power plant. The main challenges are caused particularly by ageing plant technology, plant modifications, the application of new safety and operational requirements, and in general by human factors arising from migration of plant personnel and possible human failures. The IAEA Incident Reporting System (IRS) shows that on average 25% of recorded events could be caused by configuration errors or deficiencies. CM processes correctly applied ensure that the construction, operation, maintenance and testing of a physical facility are in accordance with design requirements as expressed in the d...

  15. Coupling/Tradeoff Analysis and Novel Containment Control for Reactive Power, Output Voltage in Islanded Micro-Grid

    DEFF Research Database (Denmark)

    Han, Renke; Meng, Lexuan; Guerrero, Josep M.

    2016-01-01

    Based on the hierarchical control structure in islanded Micro-Grid (MG) systems, the coupling/tradeoff effects in different control levels are analyzed in details. In the primary level, analyses of the coupling effects among droop control gains, line impedance differences, output reactive power...

  16. Evaluation of Advanced Data Centre Power Management Strategies

    NARCIS (Netherlands)

    Postema, Björn F.; Haverkort, Boudewijn R.

    2018-01-01

    In recent work, we proposed a new specification language for power management strategies as an extension to our AnyLogic-based simulation framework for the trade-off analysis of power and performance in data centres. In this paper, we study the quality of such advanced power management strategies

  17. Nuclear power plant life management and longer-term operation

    International Nuclear Information System (INIS)

    2006-01-01

    This book, prepared by NEA member country experts, contains data and analyses relevant to nuclear power plant life management and the plants' extended, longer-term operation (LTO). It addresses technical, economic and environmental aspects and provides insights into the benefits and challenges of plant life management and LTO. It will be of interest to policy makers and senior managers in the nuclear power sector and governmental bodies involved in nuclear power programme design and management. The data and information on current trends in nuclear power plant life management will be useful to researchers and analysts working in the field of nuclear energy system assessment. (authors)

  18. User guide to power management for PCs and monitors

    Energy Technology Data Exchange (ETDEWEB)

    Nordman, B.; Piette, M.A.; Kinney, K.; Webber, C. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.

    1997-01-01

    Power management of personal computers (PCs) and monitors has the potential to save significant amounts of electricity as well as deliver other economic and environmental benefits. The Environmental Protection Agency`s ENERGY STAR{reg_sign} program has transformed the PC market so that equipment capable of power management is now widely available. However, previous studies have found that many Energy Star compliant computer systems are not accomplishing energy savings. The principal reasons for this are systems not being enabled for power management or a circumstance that prevents power management from operating. This guide is intended to provide information to computer support workers to increase the portion of systems that successfully power manage. The guide introduces power management concepts and the variety of benefits that power management can bring. It then explains how the parts of a computer system work together to enter and leave power management states. Several common computer system types are addressed, as well as the complications that networks bring to power management. Detailed instructions for checking and configuring several system types are provided, along with trouble shooting advice. The guide concludes with a discussion of how to purchase Energy Star compliant systems and future directions for power management of PCs and related equipment.

  19. Innovation of power management structure in Czechoslovakia and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Cibula, M

    1979-01-01

    The estimate is briefly indicated of power demand in Czechoslovakia till 1990 with the objective of attaining 142 mil. tonnes of specific fuel in that year. The demand will be met from domestic resources by 49%, exports by 44.2% and nuclear power by 6.8%. A brief comparison is presented of capital and fuel costs of brown coal fired power plants, hydroelectric plants and nuclear power plants in Czechoslovakia in 1990.

  20. Power, politics, and top management team characteristics: do they matter?

    Science.gov (United States)

    Gerowitz, M B

    1998-01-01

    This study assesses the contributions of the leader power and top management team characteristics to perceived strategic capability. Low age heterogeneity and low tenure heterogeneity were found to have a positive association with perceived adaptability. High diversity in educational specialization was also found to be positively associated with adaptability. Top management perceptions of CEO power were, however, lower among high adaptors. Implications for leadership research, senior management recruitment, and the design of management development for top management teams are discussed.

  1. Investigation of the behavior of a three phase grid-connected photovoltaic system to control active and reactive power

    Energy Technology Data Exchange (ETDEWEB)

    Tsengenes, Georgios; Adamidis, Georgios [Department of Electrical Engineering and Computer Engineering, Democritus University of Thrace, University Campus Kimmeria, 67100 Xanthi (Greece)

    2011-01-15

    In this paper, a photovoltaic (PV) system, with maximum power point tracking (MPPT), connected to a three phase grid is presented. The connection of photovoltaic system on the grid takes place in one stage using voltage source inverter (VSI). For a better utilization of the photovoltaic system, the control strategy applied is based on p-q theory. According to this strategy during sunlight the system sends active power to the grid and at the same time compensates the reactive power of the load. In case there is no sunlight (during the night for instance), the inverter only compensates the reactive power of the load. In this paper the use of p-q theory to supply the grid with active power and compensate the reactive power of the load is investigated. The advantage of this control strategy is that the photovoltaic system is operated the whole day. Furthermore, the p-q theory uses simple algebraic calculations without demanding the use of PLL to synchronize the inverter with the grid. (author)

  2. Management of difference in a nuclear power project

    International Nuclear Information System (INIS)

    Guo Ruiting

    2012-01-01

    The Thesis dissertate the application of Management of Difference in a Nuclear Power Project from nuclear safety regulation requirement, selection of a nuclear power plant site, engineering and procurement, construction, operation and maintenance, quality management, schedule management and experience feedback aspects. (author)

  3. Configuration management in nuclear power plants

    International Nuclear Information System (INIS)

    2003-01-01

    Configuration management (CM) is the process of identifying and documenting the characteristics of a facility's structures, systems and components of a facility, and of ensuring that changes to these characteristics are properly developed, assessed, approved, issued, implemented, verified, recorded and incorporated into the facility documentation. The need for a CM system is a result of the long term operation of any nuclear power plant. The main challenges are caused particularly by ageing plant technology, plant modifications, the application of new safety and operational requirements, and in general by human factors arising from migration of plant personnel and possible human failures. The IAEA Incident Reporting System (IRS) shows that on average 25% of recorded events could be caused by configuration errors or deficiencies. CM processes correctly applied ensure that the construction, operation, maintenance and testing of a physical facility are in accordance with design requirements as expressed in the design documentation. An important objective of a configuration management program is to ensure that accurate information consistent with the physical and operational characteristics of the power plant is available in a timely manner for making safe, knowledgeable, and cost effective decisions with confidence. Currently, the nuclear industry and governmental organizations are showing an increasing interest in the implementation of this process as an effective way of limiting configuration errors and related risks. In this report the necessary attributes of a good operational CM are identified. It is recognized and emphasized that a CM is one aspect of the overall management system. Nevertheless, this is an important part of managerial activity focused on the compliance of knowledge of the plant personnel, plant documentation and records with the state of the plant technology. The concepts developed in this report present a basic approach to CM, taking into

  4. An optimal reactive power control strategy for a DFIG-based wind farm to damp the sub-synchronous oscillation of a power system

    DEFF Research Database (Denmark)

    Zhao, Bin; Li, Hui; Wang, Mingyu

    2014-01-01

    This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG)-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capaciti...

  5. Managing strategic alliances in the power generation industry

    DEFF Research Database (Denmark)

    Kumar, Rajesh

    2003-01-01

    Highlights the challenges for power development developers in initiating alliances in the power generation industry. Importance of strategic alliances in the industry; Nature of the alliances in the independent power industry; Strategies for creating and sustaining value in global power development......; Management of tensions inherent in internal and external alliances....

  6. Rutile TiO2 thin films grown by reactive high power impulse magnetron sputtering

    International Nuclear Information System (INIS)

    Agnarsson, B.; Magnus, F.; Tryggvason, T.K.; Ingason, A.S.; Leosson, K.; Olafsson, S.; Gudmundsson, J.T.

    2013-01-01

    Thin TiO 2 films were grown on Si(001) substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 °C. Optical and structural properties of films were compared both before and after post-annealing using scanning electron microscopy, low angle X-ray reflection (XRR), grazing incidence X-ray diffractometry and spectroscopic ellipsometry. Both dcMS- and HiPIMS-grown films reveal polycrystalline rutile TiO 2 , even prior to post-annealing. The HiPIMS-grown films exhibit significantly larger grains compared to that of dcMC-grown films, approaching 100% of the film thickness for films grown at 700 °C. In addition, the XRR surface roughness of HiPIMS-grown films was significantly lower than that of dcMS-grown films over the whole temperature range 300–700 °C. Dispersion curves could only be obtained for the HiPIMS-grown films, which were shown to have a refractive index in the range of 2.7–2.85 at 500 nm. The results show that thin, rutile TiO 2 films, with high refractive index, can be obtained by HiPIMS at relatively low growth temperatures, without post-annealing. Furthermore, these films are smoother and show better optical characteristics than their dcMS-grown counterparts. - Highlights: • We demonstrate growth of rutile TiO 2 on Si (111) by high power impulse magnetron sputtering. • The films exhibit significantly larger grains than dc magnetron sputtered films • TiO 2 films with high refractive index are obtained without post-growth annealing

  7. ERP project implementation and risk management of nuclear power enterprise

    International Nuclear Information System (INIS)

    Wang Fei

    2008-01-01

    According to the characteristic and development trend of nuclear power enterprise informatization, combined with the general ERP implementation experience, the method is proposed to ensure the successful implementation and risk management of ERP project in nuclear power enterprise. (authors)

  8. Supervisory Control for Real Time Reactive Power Flow Optimization in Islanded Microgrids

    DEFF Research Database (Denmark)

    Milczarek, Adam; Vasquez, Juan Carlos; Malinowski, Mariusz

    2013-01-01

    -line measurements. Similarly to any process system, MG hierarchical control is divided into three levels. However, an additional control algorithm is required to manage power transmission between sources and loads, maximizing efficiency and minimizing transmission losses. This real-time optimization problem......A microgrid (MG) is a local energy system consisting of a number of energy sources, energy storage units and loads that operate connected to the main electrical grid or autonomously. MGs include wind, solar or other renewable energy sources. MGs provide flexibility, reduce the main electricity grid...... dependence and contribute to change the large centralized production paradigm to local and distributed generation. However, such energy systems require complex management, advanced control and optimization. Interest on MGs hierarchical control has increased due to the availability of cheap on...

  9. Single-point reactive power control method on voltage rise mitigation in residential networks with high PV penetration

    DEFF Research Database (Denmark)

    Hasheminamin, Maryam; Agelidis, Vassilios; Ahmadi, Abdollah

    2018-01-01

    Voltage rise (VR) due to reverse power flow is an important obstacle for high integration of Photovoltaic (PV) into residential networks. This paper introduces and elaborates a novel methodology of an index-based single-point-reactive power-control (SPRPC) methodology to mitigate voltage rise by ...... system with high r/x ratio. Efficacy, effectiveness and cost study of SPRPC is compared to droop control to evaluate its advantages.......Voltage rise (VR) due to reverse power flow is an important obstacle for high integration of Photovoltaic (PV) into residential networks. This paper introduces and elaborates a novel methodology of an index-based single-point-reactive power-control (SPRPC) methodology to mitigate voltage rise...... by absorbing adequate reactive power from one selected point. The proposed index utilizes short circuit analysis to select the best point to apply this Volt/Var control method. SPRPC is supported technically and financially by distribution network operator that makes it cost effective, simple and efficient...

  10. Integrated project risk management of nuclear power projects

    International Nuclear Information System (INIS)

    Wang Xiaohui; Xu Yuanhui

    2001-01-01

    The concept and the features of risks in nuclear power projects are introduced, and in terms of nuclear power projects' own features, the Nuclear Power Project Integrated Risk Management Model is presented. The identification, estimation, evaluation, response plan development, control of risks and the theoretical basis of risk management are discussed. The model has feedback and control functions in order to control and manage the risks dynamically

  11. Prognostic Health Management for Avionics System Power Supplies

    National Research Council Canada - National Science Library

    Orsagh, Rolf; Brown, Douglas; Roemer, Michael; Dabney, Thomas; Hess, Andrew

    2005-01-01

    This paper presents an integrated approach to switching mode power supply health management that implements techniques from engineering disciplines including statistical reliability modeling, damage...

  12. Process stabilization by peak current regulation in reactive high-power impulse magnetron sputtering of hafnium nitride

    International Nuclear Information System (INIS)

    Shimizu, T; Villamayor, M; Helmersson, U; Lundin, D

    2016-01-01

    A simple and cost effective approach to stabilize the sputtering process in the transition zone during reactive high-power impulse magnetron sputtering (HiPIMS) is proposed. The method is based on real-time monitoring and control of the discharge current waveforms. To stabilize the process conditions at a given set point, a feedback control system was implemented that automatically regulates the pulse frequency, and thereby the average sputtering power, to maintain a constant maximum discharge current. In the present study, the variation of the pulse current waveforms over a wide range of reactive gas flows and pulse frequencies during a reactive HiPIMS process of Hf-N in an Ar–N 2 atmosphere illustrates that the discharge current waveform is a an excellent indicator of the process conditions. Activating the reactive HiPIMS peak current regulation, stable process conditions were maintained when varying the N 2 flow from 2.1 to 3.5 sccm by an automatic adjustment of the pulse frequency from 600 Hz to 1150 Hz and consequently an increase of the average power from 110 to 270 W. Hf–N films deposited using peak current regulation exhibited a stable stoichiometry, a nearly constant power-normalized deposition rate, and a polycrystalline cubic phase Hf-N with (1 1 1)-preferred orientation over the entire reactive gas flow range investigated. The physical reasons for the change in the current pulse waveform for different process conditions are discussed in some detail. (paper)

  13. Analysis of Participant Reactivity in Dyads Performing a Videotaped Conflict-Management Task.

    Science.gov (United States)

    Semeniuk, Yulia Y; Riesch, Susan K

    2011-01-01

    Videotaping is used frequently in nursing research. A threat to the validity of videotaping is participant reactivity, that is, being recorded by a camera may influence the behavior of interest. This paper's purpose is to report how youth ages 10 to 14 years old and their parent viewed participation in a videotaped conflict-management task. Five dyads, who were part of a randomized clinical trial testing an intervention to promote parent-child communication, participated in a structured interview. All parents were mothers. Youth were eighth graders. Three were boys and two were girls. Findings indicated that (a) dyads felt that the videotaped interaction had a progression of feeling unnatural in the beginning to feeling natural toward the end, (b) dyads found it relatively easy to choose a topic of discussion, and (c) dyads felt that the discussions were meaningful. Based on these data, recommendations for researchers to reduce participant reactivity are provided.

  14. Ship nuclear power device of cable aging management

    International Nuclear Information System (INIS)

    Wei Hua; Chen Miao; Chen Tao

    2012-01-01

    Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

  15. Computation, measurement and analysis of the reactivity-to-power-transfer-function for the sodium cooled nuclear power plant KNK I

    International Nuclear Information System (INIS)

    Hoppe, P.; Mitzel, F.

    1977-02-01

    The Reactivity-to-Power-Transfer-Function for the sodium cooled nuclear power plant KNK I (Kompakte Natriumgekuehlte Kernenergieanlage) has been measured and compared with theoretical results. The measurements have been performed with the help of pseudostochastic reactivity perturbations. The transfer function has been determined by computing the auto- and cross-power-spectral-densities for the reactivity- and neutron flux signals. The agreement between the experimental and theoretical transfer function could be improved by adjusting the reactivity coefficients. The applications of these measurements with respect to reactor diagnosis and malfunction detection are discussed. For this purpose the accuracy of the measured transfer function is of great importance. Therefore an extensive error analysis has been performed. It turned out, that the inherent instability of the reactor without control system and the feedback by the primary coolant system were the reasons for comparatively big systematical errors. The conditions have been derived under which these types of errors can be considerably reduced. The conclusions can also be applied to analogical measurements at fast sodium cooled reactors. Because of their inherent stability the systematical errors will be reduced. (orig.) [de

  16. Electric Power Supply Chain Management Addressing Climate Change

    DEFF Research Database (Denmark)

    Wang, Xiao-Hui; Cong, Ronggang

    2012-01-01

    Supply chain management played a critical role in the electric power industrial chain optimization. The purpose of this paper was to review a sample of the literature relating to supply chain management and its possible applications in electricity power system, especially in the context of climate...... change. The study compared the difference between electric power supply chain management and traditional supply chain management. Furthermore, some possible research topics are addressed. The aim of this paper was to promote the application of supply chain management in the China electricity sector...

  17. Planning construction of integrative schedule management for nuclear power project

    International Nuclear Information System (INIS)

    Zeng Zhenglin; Wang Wenying; Peng Fei

    2012-01-01

    This paper introduces the planning construction of integrative schedule management for Nuclear Power Project. It details schedule management system and the requirement of schedulers and the mode of three schedule management flats. And analysis it combing with the implementation of construction water and all special schedules before FCD to further propose the improving and researching direction for the integrative schedule management. (authors)

  18. Determination of the excess of reactivity in a nuclear configuration and its influence on the power level

    International Nuclear Information System (INIS)

    Zuniga, Agustin; Tapia, Jose

    2014-01-01

    This work presents experimental results which show that the critical position of a given nuclear configuration changes with the reactor power (expressed by the current measurement). Thus, if the current is 0.6 x 10 -11 A (1 W), then the critical position is, BC1 = 0.0 % while 0.6 x 10 -9 A (100 W), BC1= 46.5 %. The difference is apparent because under a current of 10 -10 A, the reactivity is not significant. Therefore, it is recommended that for reactors like the RP-10 with a lot of neutrons at the 'background' level, the excess reactivity must be measured in current as 0.6 x 10 -9 A (100 W) not less. Finally, the excess of reactivity for the N o 42 configuration was determined, which was 3032 pcm with uncertainty less than 1 %. (authors).

  19. [Effects of Reactive Jump Training in Handball Players Regarding Jump Height and Power Development in the Triceps Surae Muscle].

    Science.gov (United States)

    Rensing, N; Westermann, A; Möller, D; von Piekartz, H

    2015-12-01

    Studies have shown changes in the technical and physical demands in modern handball. The game has increased considerably in speed, power and dynamics. Jump training has, therefore, become ever more important in the training of the athletes. These developments contribute to the fact that handball is now one of the most injury-prone types of sport, with the lower extremities being most frequently affected. Reactive jump training is not only used in training by now, but also increasingly in injury prevention. The aim of this study was to investigate the effectiveness of reactive jump training with handball players. 21 regional league handball players were randomly divided into an intervention group (n = 12) and a control group (n = 9). The intervention group completed a six-week reactive jump training programme while the control group went through a non-specific training programme. Jump height (squat and counter movement jump), isokinetic and isometric maximum power as well as muscle activity served as measuring parameters. A comparison of the intervention and control groups revealed that the reactive jump training led to significant improvements in jump height. The isometric and isokinetic maximum power measurements and the electromyographic activities of the triceps surae muscle demonstrated an improvement in the values within the intervention group. However, this improvement was not significant compared with the control group. Likewise both jumps correlated with the muscle activity of the soleus muscle as shown by electromyography. A moderate correlation was noticed between the isokinetic maximum power measurement and the electromyographic activity of the soleus and gastrocnemius medialis muscles. Furthermore, the correlations of the isometric and isokinetic maximum power meas-urements resulted in a strong correlation coefficient. This study revealed a significant increase in jump height after reactive jump training. There was no significant difference in

  20. Strengthening of nuclear power plant construction safety management

    International Nuclear Information System (INIS)

    Yu Jun

    2012-01-01

    The article describes the warning of the Fukushima nuclear accident, and analyzes the major nuclear safety issues in nuclear power development in China, problems in nuclear power plants under construction, and how to strengthen supervision and management in nuclear power construction. It also points out that the development of nuclear power must attach great importance to the safety, and nuclear power plant construction should strictly implement the principle of 'safety first and quality first'. (author)

  1. Assessment and Management of Aging in Phenix Nuclear Power Plant

    International Nuclear Information System (INIS)

    Dumarcher, V.; Bourrier, J.L.; Chaucheprat, P.; Boulegue, D.

    2006-01-01

    The combination of one or several processes of ruins can involve the materials failure of a nuclear power plant. These processes arise from the external agents action such as the pressure, the mechanical efforts, the heat flows and the radiations constitute the whole of the 'actions' of the surrounding medium. The prolongation and the repetition of these effects can involve a deterioration of the machine. In accordance with the decree of February 26, 1974, the PWR operator must be firstly, sure that the system is controlled according to the situations considered in the file of dimensioning and secondly, be able to know anytime the life of the equipment. The physical phenomena which cause the structures ruin are less complex in the PWR than in the SFR. In the SFR, the high temperatures imposed on components for long periods can involve a significant creep. In the course of time, this deformations accelerate the release of fatigue cracks. To consider the creep, the reactor lifespan is correlated at the numbers of thermals transients envisaged initially. To realize the management of aging in Phenix power plant, it is necessary to carry out an individualized monitoring of the structures and not only on the vessel. We must ensure the good state and/or the correct operation of the significant stations for safety which are the control of the reactivity, the movement of control rods, the primary sodium containment and the decay heat removal. For that, we monitor the main vessel, the conical skirt, the IHX and the Core Cover Plug. A profound knowledge of the thermal transients of the past is necessary to carry out an effective assessment. In order to guarantee that any harmful situation is well taken into the management of aging, we monitor permanently certain measurements (primary and secondary pump speed, hot and cold pool temperatures, IHX-main vessel and reactor roof temperatures). We present in the article the scientific method used in the Physics Section. A logical

  2. Transient voltage control of a DFIG-based wind power plant for suppressing overvoltage using a reactive current reduction loop

    Directory of Open Access Journals (Sweden)

    Geon Park

    2016-01-01

    Full Text Available This paper proposes a transient voltage control scheme of a doubly fed induction generator (DFIG-based wind power plant (WPP using a reactive current reduction loop to suppress the overvoltage at a point of interconnection (POI and DFIG terminal after a fault clearance. The change of terminal voltage of a DFIG is monitored at every predefined time period to detect the fault clearance. If the voltage change exceeds a set value, then the reactive current reduction loop reduces the reactive current reference in the DFIG controller using the step function. The reactive current injection of DFIGs in a WPP is rapidly reduced, and a WPP can rapidly suppress the overvoltage at a fault clearance because the reactive current reference is reduced. Using an electromagnetic transients program–released version (EMTP–RV simulator, the performance of the proposed scheme was validated for a model system comprising 20 units of a 5-MW DFIG considering various scenarios, such as fault and wind conditions. Test results show that the proposed scheme enables a WPP to suppress the overvoltage at the POI and DFIG terminal within a short time under grid fault conditions.

  3. Positioning strategies for decentralized energy resources providing reactive power voltage control; Anlagenauswahl und -positionierung zur Spannungsstuetzung mittels Blindleistungsmanagement dezentraler Erzeugungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Matrose, Claas; Goedde, Markus; Cramer, Moritz; Potratz, Fabian; Pollok, Thomas; Schnettler, Armin [RWTH Aachen Univ. (Germany). Inst. fuer Hochspannungstechnik

    2012-07-01

    The integration of decentralized generation into power distribution grids in Germany has reached a level at which more and more grid reinforcement is required in order to keep voltages within the given limits. The consumption of reactive power by decentralized generation systems can reduce the voltage rise, which is caused by active power in-feed of such systems. Caused by different characteristics of overhead lines and cables, this effect significantly varies. Parameter studies of four commonly used types of lines, of different power ratings of decentralized generation systems as well as different lengths of lines can quantify the effects. It can be shown that - depending on the characteristics of a specific grid - the grid capacity for power in-feed can be increased by factors between 1.5 and 10. (orig.)

  4. Engineering schedule control of nuclear power project planning and management

    International Nuclear Information System (INIS)

    Meng Hao

    2014-01-01

    Nuclear power design is the important part of project management of nuclear power project, it is the way to control the project organization, design schedule, design progress, design quality and cost control. The good schedule system and control is the key to the success for the project. It is also analyzed the problem during the project, by using some theory and analyze the project structure, design schedule management, IED and document management and interface management propose some new idea for better improve the design management to finally better improve the management quality and efficiency. (author)

  5. Distributing radiation management system of nuclear power plants

    International Nuclear Information System (INIS)

    Mihoya, Eiichi; Akashi, Michio

    1999-01-01

    The importance of radiation management for nuclear facilities including nuclear power plants has increased as the general public understanding has progressed, and necessary information for management must be processed exactly and quickly. In nuclear power plants, radiation management is performed by each individual operation, and collected information is managed by the system of each operation. The distributing radiation management system has been developed aiming to use a general-purpose LAN and make quick and efficient use of information managed by individual operations. This paper describes the system configuration and functions. (author)

  6. A nuclear power enterprise debt management system construction Based on Sanmen Nuclear Power Co., LTD, debt risk management case analysis

    International Nuclear Information System (INIS)

    Wu Yan; Liu Shuqing

    2010-01-01

    Building nuclear power enterprises need huge investment , often tens of billions RMB. How to do a good job in corporate debt risk management, becoming powerful large-scale development of nuclear power ,ensuring the supply of funds and existing debt service in the process of large-scale development of nuclear power ,is an important task. In this paper, managing the company's debt is very urgent and necessary through analysis of SMNPC financing and debt structure; through the analysis of SMNPC's debt risk management , the authors would like to explore how to build up the framework of the debt management under the large-scale development of nuclear power construction . Nuclear power enterprises need to strengthen supervision mechanism and internal control,build-up and perfect all-round debt risk manage system, keep watch on debt risk in order to ensure preservation and increment of the value of state assets. (authors)

  7. Management for nuclear power plants for safe operation

    International Nuclear Information System (INIS)

    Kueffer, K.

    1981-01-01

    This lecture covers management aspects which have an immediate bearing on safety and identifies the objectives and tasks of management which are required for safe operation of a nuclear power plant and is based on the Codes of Practice and Safety Guides of the IAEA as well as arrangements in use at the Swiss Nuclear Power Station Beznau. (orig./RW)

  8. Six sigma management and its application in nuclear power plant

    International Nuclear Information System (INIS)

    Liu Weihua; Tong Lili

    2007-01-01

    Six sigma management mode is presented. The feasibility, necessity and the steps to extend six sigma in nuclear power plant are addressed. Nuclear power plant can eliminate or decrease human errors through importing six management concept, the 'zero disfigurement' quality and operation can achieved, decreasing accident risk and realizing safety operation. (authors)

  9. Power Electronics and Thermal Management | Transportation Research | NREL

    Science.gov (United States)

    Power Electronics and Thermal Management Power Electronics and Thermal Management This is the March Gearhart's testimony. Optical Thermal Characterization Enables High-Performance Electronics Applications New vehicle electronics systems are being developed at a rapid pace, and NREL is examining strategies to

  10. Time series characterization of gaming workload for runtime power management

    NARCIS (Netherlands)

    Dietrich, B.; Goswami, D.; Chakraborty, S.; Guha, A.; Gries, M.

    2015-01-01

    Runtime power management using dynamic voltage and frequency scaling (DVFS) has been extensively studied for video processing applications. But there is only a little work on game power management although gaming applications are now widely run on battery-operated portable devices like mobile

  11. The nuclear power corporation's foreign exchange risk management research

    International Nuclear Information System (INIS)

    Zhang Yi

    2012-01-01

    To manage and control foreign exchange rate risk under the floating exchange rate system, historical simulation method of VaR model has been utilized to evaluate the nuclear power corporation's foreign exchange risk and the risk causation has been analyzed. Finally, the measure of enhancing the nuclear power corporation's foreign exchange rate risk management level has been exposed for sharing. (author)

  12. Containment and Consensus-based Distributed Coordination Control for Voltage Bound and Reactive Power Sharing in AC Microgrid

    DEFF Research Database (Denmark)

    Han, Renke; Meng, Lexuan; Ferrari-Trecate, Giancarlo

    2017-01-01

    This paper offers a highly flexible and reliable control strategy to achieve voltage bounded regulation and accurate reactive power sharing coordinately in AC Micro-Grids. A containment and consensus-based distributed coordination controller is proposed, by which each output voltage magnitude can...... be bounded within a reasonable range and the accurate reactive power sharing among distributed generators can be also achieved. Combined with the two proposed controllers and electrical part of the AC Micro-Grid, a small signal model is fully developed to analyze the sensitivity of different control...... parameters. The effectiveness of the proposed controller in case of load variation, communication failure, plug-and-play capability are verified by the experimental setup as an islanded Micro-Grid....

  13. A Data-Driven Stochastic Reactive Power Optimization Considering Uncertainties in Active Distribution Networks and Decomposition Method

    DEFF Research Database (Denmark)

    Ding, Tao; Yang, Qingrun; Yang, Yongheng

    2018-01-01

    To address the uncertain output of distributed generators (DGs) for reactive power optimization in active distribution networks, the stochastic programming model is widely used. The model is employed to find an optimal control strategy with minimum expected network loss while satisfying all......, in this paper, a data-driven modeling approach is introduced to assume that the probability distribution from the historical data is uncertain within a confidence set. Furthermore, a data-driven stochastic programming model is formulated as a two-stage problem, where the first-stage variables find the optimal...... control for discrete reactive power compensation equipment under the worst probability distribution of the second stage recourse. The second-stage variables are adjusted to uncertain probability distribution. In particular, this two-stage problem has a special structure so that the second-stage problem...

  14. Autonomous Control of Current and Voltage Controlled DG Interface Inverters for Reactive Power Sharing and Harmonics Compensation in Islanded Microgrids

    DEFF Research Database (Denmark)

    Mousazadeh, Seyyed Yousef; Jalilain, Alireza; Savaghebi, Mehdi

    2018-01-01

    In microgrids, Voltage Source Inverters (VSIs) interfacing Distributed Generation (DG) units can be operated in Voltage or Current Controlled Modes (VCM/CCM). In this paper, a coordinated control of CCM and VCM units for reactive power sharing and voltage harmonics compensation is proposed....... This decentralized control scheme is based on the local measurement of signals. In this way, the need for communication links is removed which results in a simpler and more reliable structure compared to the communication based control structures. To be more exact, the VCM units contribute to harmonics compensation....... Experimental and simulation studies show that the harmonics compensation is achieved by using only local measurements in presence of virtual admittance/impedance schemes of CCM/VCM units. Furthermore, it is demonstrated that the reactive power sharing among the CCM and VCM units is obtained based...

  15. Advanced Power Converter for Universal and Flexible Power Management in Future Electricity Network

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Bassett, R.

    2007-01-01

    converters for grid connection of renewable sources will be needed. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents the overall structure and the control aspects of an advanced power converter for universal and flexible power......More "green" power provided by Distributed Generation will enter into the European electricity network in the near future. In order to control the power flow and to ensure proper and secure operation of this future grid, with an increased level of the renewable power, new power electronic...

  16. Managing Power Relations in Doctoral Education through Research ...

    African Journals Online (AJOL)

    Drawing mainly on the power theory of Foucault, this paper examines the power relations existing in research supervision. It explores the importance of mentoring as a key to managing such power relations. Mentoring is an empowering process of nurturing students with sufficient tools for research. The conditions for ...

  17. Smart Power Management of DC Microgrids in Future Milligrids

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Davari, Pooya

    2016-01-01

    In this paper a novel droop approach for power management in low voltage dc MicroGrids (MGs) based on a master-slave concept is presented. A virtual frequency is injected by a master unit, which is proportional to its output power. Other slave units determine their output power according to the c...

  18. Computerized nuclear material database management system for power reactors

    International Nuclear Information System (INIS)

    Cheng Binghao; Zhu Rongbao; Liu Daming; Cao Bin; Liu Ling; Tan Yajun; Jiang Jincai

    1994-01-01

    The software packages for nuclear material database management for power reactors are described. The database structure, data flow and model for management of the database are analysed. Also mentioned are the main functions and characterizations of the software packages, which are successfully installed and used at both the Daya Bay Nuclear Power Plant and the Qinshan Nuclear Power Plant for the purposed of handling nuclear material database automatically

  19. Purchasing management experience of Haiyang nuclear power project construction period

    International Nuclear Information System (INIS)

    Ma Yuqin

    2013-01-01

    Purchasing is one of the important aspects to ensure the safety and quality of the nuclear power plant. This paper, combining the purchasing peculiarity and purchasing process of Haiyang nuclear power project, summarizes experiences of Haiyang nuclear power project in promoting its purchasing management level in aspects of purchasing method choosing, purchasing plan management, purchasing process optimization, purchasing contract implementation and purchasing surveillance, etc. (author)

  20. Research on Risk Management and Power Supplying Enterprise Control

    Science.gov (United States)

    Shen, Jianfei; Wang, Yige

    2017-09-01

    This paper derived from the background that electric power enterprises strengthen their risk management under requirements of the government. For the power industry, we explained the risk management theory, analysed current macro environment as well as basic situation, then classified and interpreted the main risks. In a case study on a power bureau, we established a risk management system based on deep understanding about the characteristics of its organization system and risk management function. Then, we focused on risks in operation as well as incorrupt government construction to give a more effective framework of the risk management system. Finally, we came up with the problems and specific countermeasures in risk management, which provided a reference for other electric power enterprises.

  1. Monitoring temperature reactivity coefficient by noise method in a NPP at full power

    International Nuclear Information System (INIS)

    Aguilar, O.; Por, G.

    1987-04-01

    A new method based on noise measurement was used to estimate the temperature reactivity coefficient of the PAKS-2 reactor during the entire fuel cycle. Based on the measurements it is possible to measure the dependence of reactivity coefficient on boron concentration. Good agreement was found between the results obtained by the new method and by the conventional ones. Based on this method a new equipment can be develop which assures permanent measurements during operation. (author)

  2. In-core power sharing and fuel requirement study for a decommissioning Boiling Water Reactor using the linear reactivity model

    International Nuclear Information System (INIS)

    Chen, Chung-Yuan; Tung, Wu-Hsiung; Yaur, Shung-Jung; Kuo, Weng-Sheng

    2014-01-01

    Highlights: • Linear reactivity model (LRM) was modified and applied to Boiling Water Reactor. • The power sharing and fuel requirement study of the last cycle and two cycles before decommissioning was implemented. • The loading pattern design concept for the cycles before decommissioning is carried out. - Abstract: A study of in-core power sharing and fuel requirement for a decommissioning BWR (Boiling Water Reactor) was carried out using the linear reactivity model (LRM). The power sharing of each fuel batch was taken as an independent variable, and the related parameters were set and modified to simulate actual cases. Optimizations of the last cycle and two cycles before decommissioning were both implemented; in the last-one-cycle optimization, a single cycle optimization was carried out with different upper limits of fuel batch power, whereas, in the two-cycle optimization, two cycles were optimized with different cycle lengths, along with two different optimization approaches which are the simultaneous optimization of two cycles (MO) and two successive single-cycle optimizations (SO). The results of the last-one-cycle optimization show that it is better to increase the fresh fuel power and decrease the thrice-burnt fuel power as much as possible. It also shows that relaxing the power limit is good to the fresh fuel requirement which will be reduced under lower power limit. On the other hand, the results of the last-two-cycle (cycle N-1 and N) optimization show that the MO is better than SO, and the power of fresh fuel batch should be decreased in cycle N-1 to save its energy for the next cycle. The results of the single-cycle optimization are found to be the same as that in cycle N of the multi-cycle optimization. Besides that, under the same total energy requirement of two cycles, a long-short distribution of cycle length design can save more fresh fuel

  3. Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

    International Nuclear Information System (INIS)

    MM Hall

    2006-01-01

    A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing

  4. A New Approach to Optimal Allocation of Reactive Power Ancillary Service in Distribution Systems in the Presence of Distributed Energy Resources

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2015-11-01

    Full Text Available One of the most important Distribution System Operators (DSO schemes addresses the Volt/Var control (VVC problem. Developing a cost-based reactive power dispatch model for distribution systems, in which the reactive powers are appropriately priced, can motivate Distributed Energy Resources (DERs to participate actively in VVC. In this paper, new reactive power cost models for DERs, including synchronous machine-based DGs and wind turbines (WTs, are formulated based on their capability curves. To address VVC in the context of competitive electricity markets in distribution systems, first, in a day-ahead active power market, the initial active power dispatch of generation units is estimated considering environmental and economic aspects. Based on the results of the initial active power dispatch, the proposed VVC model is executed to optimally allocate reactive power support among all providers. Another novelty of this paper lies in the pricing scheme that rewards transformers and capacitors for tap and step changing, respectively, while incorporating the reactive power dispatch model. A Benders decomposition algorithm is employed as a solution method to solve the proposed reactive power dispatch, which is a mixed integer non-linear programming (MINLP problem. Finally, a typical 22-bus distribution network is used to verify the efficiency of the proposed method.

  5. Impact of wind power plant reactive current injection during asymmetrical grid faults

    DEFF Research Database (Denmark)

    Göksu, Ömer; Teodorescu, Remus; Bak, Claus Leth

    2013-01-01

    As more renewable energy sources, especially more wind turbines (WTs) are installed in the power system; grid codes for wind power integration are being generated to sustain stable power system operation with non-synchronous generation. Common to most of the grid codes, wind power plants (WPPs...... faults, is investigated, which was not considered in the wind power impact studies before....

  6. Tianwan nuclear power plant operation and management practices

    International Nuclear Information System (INIS)

    Gu Yingbing

    2010-01-01

    Tianwan Nuclear Power Station is a high-tech cooperation project in nuclear sector in the spirit of promoting the political relationship, economic trading and international strategic partnership between China and Russia. It was listed as one of the key nuclear projects to be constructed during the 'Ninth Five-Year' Plan. In this article the author summarizes and feedbacks the practices of operation management in Tianwan Nuclear Power Station in 7 aspects of safety culture construction, operation team building, daily operation management, operation document management, plant chemistry control and management, solid, liquid and gaseous waste management and control of operation performance indicators. (author)

  7. Energy management strategies for vehicle power nets

    NARCIS (Netherlands)

    Koot, M.W.T.; Jager, de A.G.; Kessels, J.T.B.A.; Heemels, W.P.M.H.; Bosch, van den P.P.J.

    2004-01-01

    In the near future a significant increase in electric power consumption in vehicles is to be expected. To limit the associated increase in fuel consumption and exhaust emissions, smart strategies for the generation, storage/retrieval, distribution, and consumption of the electric power can be used.

  8. Efficient Load Scheduling Method For Power Management

    Directory of Open Access Journals (Sweden)

    Vijo M Joy

    2015-08-01

    Full Text Available An efficient load scheduling method to meet varying power supply needs is presented in this paper. At peak load times the power generation system fails due to its instability. Traditionally we use load shedding process. In load shedding process disconnect the unnecessary and extra loads. The proposed method overcomes this problem by scheduling the load based on the requirement. Artificial neural networks are used for this optimal load scheduling process. For generate economic scheduling artificial neural network has been used because generation of power from each source is economically different. In this the total load required is the inputs of this network and the power generation from each source and power losses at the time of transmission are the output of the neural network. Training and programming of the artificial neural networks are done using MATLAB.

  9. Development and management of world nuclear power in 2012

    International Nuclear Information System (INIS)

    2012-01-01

    It deals with development and management of nuclear power of foreign countries by the 1st of January 2012 with tables and figures, which includes outline of investigation, operation experience of nuclear power plant of the world, the cardinal number according to the type of operating power plant of the world, using Mox of the world and site of nuclear power plant of the world. There are list of world nuclear power plant, explanation of abbreviations, address book of nuclear power plant of the world and table and figure of major nuclear fuel cycle.

  10. Reactive Power Management in Islanded Microgrid – Proportional Power Sharing in Hierarchical Droop Control

    DEFF Research Database (Denmark)

    Milczarek, Adam; Malinowski, Mariusz; Guerrero, Josep M.

    2015-01-01

    A microgrid (MG) is a local energy system consisting a number of energy sources (e.g. wind turbine or solar panels among others), energy storage units and loads that operate connected to the main electrical grid or autonomously. MGs provide flexibility, reduce the main electricity grid dependence...

  11. Nuclear power company activity based costing management analysis

    International Nuclear Information System (INIS)

    Xu Dan

    2012-01-01

    With Nuclear Energy Industry development, Nuclear Power Company has the continual promoting stress of inner management to the sustainable marketing operation development. In view of this, it is very imminence that Nuclear Power Company should promote the cost management levels and built the nuclear safety based lower cost competitive advantage. Activity based costing management (ABCM) transfer the cost management emphases from the 'product' to the 'activity' using the value chain analysis methods, cost driver analysis methods and so on. According to the analysis of the detail activities and the value chains, cancel the unnecessary activity, low down the resource consuming of the necessary activity, and manage the cost from the source, achieve the purpose of reducing cost, boosting efficiency and realizing the management value. It gets the conclusion from the detail analysis with the nuclear power company procedure and activity, and also with the selection to 'pieces analysis' of the important cost related project in the nuclear power company. The conclusion is that the activities of the nuclear power company has the obviously performance. It can use the management of ABC method. And with the management of the procedure and activity, it is helpful to realize the nuclear safety based low cost competitive advantage in the nuclear power company. (author)

  12. Annual report on nuclear power station operational management, 1984

    International Nuclear Information System (INIS)

    1985-09-01

    As of the end of fiscal year 1984, 28 nuclear power plants were in operation in Japan, the total power output of which was 20.56 million kW, equivalent to 22.9 % of the total generated electric power in Japan. Now nuclear power generation bears a very important role in the stable supply and cost stabilization of electric power. The result of the capacity factor in fiscal year 1984 was 73.9 %, which showed that the nuclear power generation and safety management technologies in Japan are at the top level in the world. However, in order that nuclear power generation accomplishes the role as main power source sufficiently hereafter by increasing the number of plants, the reliability and economical efficiency must be further improved, and especially the safety management and operational management become important. For the purpose, the operational experience accumulated so far must be effectively utilized. In this book, the outline of the administration on the safety regulation of nuclear power generation, the state of operation of nuclear power plants, the state of accidents and failures, the state of regular inspections and so on are summarized. Also the state of radioactive waste management and the radiation control for workers are reported. (Kako, I.)

  13. Discussion of manage mode for nuclear power construcation in China

    International Nuclear Information System (INIS)

    Gao Mingshi; Chen Hua

    2007-01-01

    This paper analyzed the development status of management mode for NPP construction and nuclear power engineering companies. Considering the national development plan of nuclear power, and making reference of the experiences of the successful construction of NPPs, the management mode for NPP construction in which the nuclear engineering companies are the main factors have been discussed. This paper proposed that EPC/TurnKey as the management mode for the nuclear power construction, led by the owner, and constructed by engineering companies according to the contracts, so as to establish a construction group with expertise knowledge. (authors)

  14. Discussion on management of decommissioning funds for nuclear power plants

    International Nuclear Information System (INIS)

    Wang Hailiang

    2013-01-01

    Decommissioning funding is one of the major issues with regard to the policy and management of nuclear power. This paper describes current status of decommissioning of nuclear power plants in some foreign countries and narrates the practices in these countries on the estimation of decommissioning cost, the retrieval and management of decommissioning funds, and the guarantee of fund sufficiency. Based on a brief analysis of the status of decommissioning funding management for nuclear power plants in China, suggestions on tasks or activities needed to be carried out at present in the field of decommissioning funding are proposed. (authors)

  15. Formation of power management strategy at the industrial enterprises

    Science.gov (United States)

    Akimova, Elena

    2017-10-01

    The article is dedicated to energy efficiency problems. The main recommendations about the development of the system of strategic power management at the industrial enterprise offered in the research include a number of the principles, aimed at the increase of the importance of human resources in information-and-analytical and innovative functions of power management. According to the results of the current situation analyses, the author suggests using some specific indicators of human resources, as they can contribute to the energy efficiency formation. The system of standardization is considered to be the basis for the implementation of strategic power management at the enterprises.

  16. Power control and management of the grid containing largescale wind power systems

    Science.gov (United States)

    Aula, Fadhil Toufick

    The ever increasing demand for electricity has driven many countries toward the installation of new generation facilities. However, concerns such as environmental pollution and global warming issues, clean energy sources, high costs associated with installation of new conventional power plants, and fossil fuels depletion have created many interests in finding alternatives to conventional fossil fuels for generating electricity. Wind energy is one of the most rapidly growing renewable power sources and wind power generations have been increasingly demanded as an alternative to the conventional fossil fuels. However, wind power fluctuates due to variation of wind speed. Therefore, large-scale integration of wind energy conversion systems is a threat to the stability and reliability of utility grids containing these systems. They disturb the balance between power generation and consumption, affect the quality of the electricity, and complicate load sharing and load distribution managing and planning. Overall, wind power systems do not help in providing any services such as operating and regulating reserves to the power grid. In order to resolve these issues, research has been conducted in utilizing weather forecasting data to improve the performance of the wind power system, reduce the influence of the fluctuations, and plan power management of the grid containing large-scale wind power systems which consist of doubly-fed induction generator based energy conversion system. The aims of this research, my dissertation, are to provide new methods for: smoothing the output power of the wind power systems and reducing the influence of their fluctuations, power managing and planning of a grid containing these systems and other conventional power plants, and providing a new structure of implementing of latest microprocessor technology for controlling and managing the operation of the wind power system. In this research, in order to reduce and smooth the fluctuations, two

  17. Management of radioactive wastes at power reactor sites in India

    International Nuclear Information System (INIS)

    Amalraj, R.V.; Balu, K.

    Indian nuclear power programme, at the present stage, is based on natural uranium fuelled heavy water moderated CANDU type reactors except for the first nuclear power station consisting of two units of enriched uranium fuelled, light water moderated, BWR type of reactors. Some of the salient aspects of radioactive waste management at power reactor sites in India are discussed. Brief reviews are presented on treatment of wastes, their disposal and environmental aspects. Indian experience in power reactor waste management is also summarised identifying some of the areas needing further work. (auth.)

  18. Structural and optical properties of zirconia thin films deposited by reactive high-power impulse magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoli; Jin, Jie [Tianjin University, School of Electronic Information Engineering, Tianjin (China); Cheng, Jui-Ching, E-mail: juiching@ntut.edu.tw [Chang-Gung University, Department of Electronics, Taoyuan, Taiwan (China); Lee, Jyh-Wei [Ming Chi University of Technology, College of Materials Engineering, New Taipei City, Taiwan (China); Wu, Kuo-Hong [Chang-Gung University, Department of Electronics, Taoyuan, Taiwan (China); Lin, Kuo-Cheng; Tsai, Jung-Ruey [Asia University, Department of Photonics and Communication Engineering, Taichung, Taiwan (China); Liu, Kou-Chen, E-mail: jacobliu@mail.cgu.edu.tw [Chang-Gung University, Department of Electronics, Taoyuan, Taiwan (China)

    2014-11-03

    Zirconia films are deposited by reactive high power impulse magnetron sputtering (HiPIMS) technology on glass and indium-tin-oxide (ITO)/glass substrates. Preparation, microstructure and optical characteristics of the films have been studied. During deposition, the influence of the target power and duty cycle on the peak current–voltage and power density has been observed in oxide mode. Transparent thin films under different oxygen proportions are obtained on the two substrates. Atomic force microscopy measurements showed that the surface roughness of the films was lower by reactive HiPIMS than DC sputtering for all oxygen contents. The transmission and reflectance properties of differently grown zirconia films were also investigated using an ultraviolet–visible spectrophotometer. The optical transmittance of films grown on glass substrates by HiPIMS reached maximum values above 90%, which exceeded that by DC sputtering. The band edge near 5.86 eV shifted to a lower wavelength for zirconia films prepared with oxygen flow rates lower than 4.5 sccm. For the films prepared on ITO/glass substrates, the transmittance and the band gap of zirconia films were limited by ITO films; a maximum average transmittance of 84% was obtained at 4.5 sccm O{sub 2} and the energy band gap was in the range of 3.7–3.8 eV for oxygen flow rates ranging from 3.5 to 5.0 sccm. Finally, the electrical properties of zirconia films have also been discussed. - Highlights: • Zirconia films are deposited by reactive high power impulse magnetron sputtering. • Low roughness films are obtained. • Films show a high transmittance (> 90%). • Films prepared on glass have a band gap of 5.9 eV.

  19. Observation of a periodic runaway in the reactive Ar/O2 high power impulse magnetron sputtering discharge

    Directory of Open Access Journals (Sweden)

    Seyedmohammad Shayestehaminzadeh

    2015-11-01

    Full Text Available This paper reports the observation of a periodic runaway of plasma to a higher density for the reactive discharge of the target material (Ti with moderate sputter yield. Variable emission of secondary electrons, for the alternating transition of the target from metal mode to oxide mode, is understood to be the main reason for the runaway occurring periodically. Increasing the pulsing frequency can bring the target back to a metal (or suboxide mode, and eliminate the periodic transition of the target. Therefore, a pulsing frequency interval is defined for the reactive Ar/O2 discharge in order to sustain the plasma in a runaway-free mode without exceeding the maximum power that the magnetron can tolerate.

  20. Selection of nuclear power information database management system

    International Nuclear Information System (INIS)

    Zhang Shuxin; Wu Jianlei

    1996-01-01

    In the condition of the present database technology, in order to build the Chinese nuclear power information database (NPIDB) in the nuclear industry system efficiently at a high starting point, an important task is to select a proper database management system (DBMS), which is the hinge of the matter to build the database successfully. Therefore, this article explains how to build a practical information database about nuclear power, the functions of different database management systems, the reason of selecting relation database management system (RDBMS), the principles of selecting RDBMS, the recommendation of ORACLE management system as the software to build database and so on

  1. Detailed neutronic study of the power evolution for the European Sodium Fast Reactor during a positive insertion of reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Facchini, A.; Giusti, V.; Ciolini, R. [Department of Civil and Industrial Engineering (DICI), University of Pisa, Largo Lucio Lazzarino 2, I-56126 Pisa (Italy); Tuček, K.; Thomas, D. [Joint Research Centre, Institute for Energy and Transport (JRC - IET), European Commission, P.O. Box 2, NL-1755 ZG Petten (Netherlands); D' Agata, E., E-mail: elio.dagata@ec.europa.eu [Joint Research Centre, Institute for Energy and Transport (JRC - IET), European Commission, P.O. Box 2, NL-1755 ZG Petten (Netherlands)

    2017-03-15

    Highlights: • This paper studies the effect of an unexpected runway of a control rod in the ESFR. • The power peaked fuel pin within the core was identified. • The increase of the fission power density of the fuel pin has been evaluated. • Radial/axial fission power density of the power peaked fuel pin has been evaluated. - Abstract: The new reactor concepts proposed in the Generation IV International Forum require the development and validation of new components and new materials. Inside the Collaborative Project on the European Sodium Fast Reactor, several accidental scenario have been studied. Nevertheless, none of them coped with mechanical safety assessment of the fuel cladding under accidental conditions. Among the accidental conditions considered, there is the unprotected transient of overpower (UTOP), due to the insertion, at the end of the first fuel cycle, of a positive reactivity into the reactor core as a consequence of the unexpected runaway of one control rod. The goal of the study was the search for a detailed distribution of the fission power, in the radial and axial directions, within the power peaked fuel pin under the above accidental conditions. Results show that after the control rod ejection an increase from 658 W/cm{sup 3} to 894 W/cm{sup 3}, i.e. of some 36%, is expected for the power peaked fuel pin. This information will represent the base to investigate, in a future work, the fuel cladding safety margin.

  2. Wind power generation, load management and dispatch

    International Nuclear Information System (INIS)

    Canazza, V.; Cirillo, M.

    2007-01-01

    The renewed commitment of the United States and European Union for the promotion of renewable energy sources makes some reflections on the appropriate management of dispatch priority of renewable energy in Italy [it

  3. Exploration of nuclear power enterprise 'STAR' management performance evaluation system

    International Nuclear Information System (INIS)

    Wang Sen

    2005-01-01

    From the angle of nuclear power enterprise safety culture, this essay breaks the connotations of the safety culture down to nine aspects (target management, safety management, quality management, housekeeping, cost control, authorization management, teamwork, communication and continued improvement), with each aspect divided into five levels of star class according to its own characteristics. A comparison is made between the actualities of the enterprise and star management performance evaluation system to find out the gap and identify ways of continued improvement to elevate the enterprise management level, thereby developing a standard system of conducting qualitative and quantitative evaluation to the management process. Apart from its evaluation function, this system provides a guideline on the work orientation, method, and steps to elevate work level and capability for the managers performing specific management actions. It is also a system of measuring and evaluating the executive force of the company's management and its employees. (author)

  4. Managing server clusters on intermittent power

    Directory of Open Access Journals (Sweden)

    Navin Sharma

    2015-12-01

    Full Text Available Reducing the energy footprint of data centers continues to receive significant attention due to both its financial and environmental impact. There are numerous methods that limit the impact of both factors, such as expanding the use of renewable energy or participating in automated demand-response programs. To take advantage of these methods, servers and applications must gracefully handle intermittent constraints in their power supply. In this paper, we propose blinking—metered transitions between a high-power active state and a low-power inactive state—as the primary abstraction for conforming to intermittent power constraints. We design Blink, an application-independent hardware–software platform for developing and evaluating blinking applications, and define multiple types of blinking policies. We then use Blink to design both a blinking version of memcached (BlinkCache and a multimedia cache (GreenCache to demonstrate how application characteristics affect the design of blink-aware distributed applications. Our results show that for BlinkCache, a load-proportional blinking policy combines the advantages of both activation and synchronous blinking for realistic Zipf-like popularity distributions and wind/solar power signals by achieving near optimal hit rates (within 15% of an activation policy, while also providing fairer access to the cache (within 2% of a synchronous policy for equally popular objects. In contrast, for GreenCache, due to multimedia workload patterns, we find that a staggered load proportional blinking policy with replication of the first chunk of each video reduces the buffering time at all power levels, as compared to activation or load-proportional blinking policies.

  5. Fault Management of a Cold Dielectric HTS Power Transmission Cable

    International Nuclear Information System (INIS)

    Maguire, J; Allais, A; Yuan, J; Schmidt, F; Hamber, F; Welsh, Tom

    2006-01-01

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. As with conventional cables, HTS cables must be safe and reliable when abnormal conditions, such as local and through faults, occur in the power grid. Due to the unique characteristics of HTS power cables, the fault management of an HTS cable is different from that of a conventional cable. Issues, such as nitrogen bubble formation within lapped dielectric material, need to be addressed. This paper reviews the efforts that have been performed to study the fault conditions of a cold dielectric HTS power cable. As a result of the efforts, a fault management scheme has been developed, which provides both local and through faults system protection. Details of the fault management scheme with examples are presented

  6. Extreme Temperature, Rad-Hard Power Management ASIC, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a rad-hard Application Specific Integrated Circuit (ASIC) for spacecraft power management that is functional over a temperature range of...

  7. Severe accident management guidance for third Qinshan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Su Changsong

    2010-01-01

    The paper describes the background, document structure and the summaries of Severe Accident Management Guidance (SAMG) for Third Qinshan Nuclear Power Plant (TQNPP), and also introduces briefly some design features and their impacts on SAMG. (authors)

  8. Safety principles and design management of Chashma Nuclear Power Plant

    International Nuclear Information System (INIS)

    Geng Qirui; Cheng Pingdong

    1997-01-01

    The basic safety consideration and detailed design principles in the design of Chashma Nuclear Power Plant is elaborated. The management within the frame setting up by 'safety culture' and 'quality culture'

  9. Development of home power management system | Apeh | Nigerian ...

    African Journals Online (AJOL)

    Development of home power management system. ... The unit also exhibited good implementation of the timing algorithm for all programmed outputs. It switched "ON" ... This flexibility in an automation system is one strong point of this device.

  10. Hybrid electric vehicle power management system

    Science.gov (United States)

    Bissontz, Jay E.

    2015-08-25

    Level voltage levels/states of charge are maintained among a plurality of high voltage DC electrical storage devices/traction battery packs that are arrayed in series to support operation of a hybrid electric vehicle drive train. Each high voltage DC electrical storage device supports a high voltage power bus, to which at least one controllable load is connected, and at least a first lower voltage level electrical distribution system. The rate of power transfer from the high voltage DC electrical storage devices to the at least first lower voltage electrical distribution system is controlled by DC-DC converters.

  11. Mechanistic modeling of reactive soil nitrogen emissions across agricultural management practices

    Science.gov (United States)

    Rasool, Q. Z.; Miller, D. J.; Bash, J. O.; Venterea, R. T.; Cooter, E. J.; Hastings, M. G.; Cohan, D. S.

    2017-12-01

    The global reactive nitrogen (N) budget has increased by a factor of 2-3 from pre-industrial levels. This increase is especially pronounced in highly N fertilized agricultural regions in summer. The reactive N emissions from soil to atmosphere can be in reduced (NH3) or oxidized (NO, HONO, N2O) forms, depending on complex biogeochemical transformations of soil N reservoirs. Air quality models like CMAQ typically neglect soil emissions of HONO and N2O. Previously, soil NO emissions estimated by models like CMAQ remained parametric and inconsistent with soil NH3 emissions. Thus, there is a need to more mechanistically and consistently represent the soil N processes that lead to reactive N emissions to the atmosphere. Our updated approach estimates soil NO, HONO and N2O emissions by incorporating detailed agricultural fertilizer inputs from EPIC, and CMAQ-modeled N deposition, into the soil N pool. EPIC addresses the nitrification, denitrification and volatilization rates along with soil N pools for agricultural soils. Suitable updates to account for factors like nitrite (NO2-) accumulation not addressed in EPIC, will also be made. The NO and N2O emissions from nitrification and denitrification are computed mechanistically using the N sub-model of DAYCENT. These mechanistic definitions use soil water content, temperature, NH4+ and NO3- concentrations, gas diffusivity and labile C availability as dependent parameters at various soil layers. Soil HONO emissions found to be most probable under high NO2- availability will be based on observed ratios of HONO to NO emissions under different soil moistures, pH and soil types. The updated scheme will utilize field-specific soil properties and N inputs across differing manure management practices such as tillage. Comparison of the modeled soil NO emission rates from the new mechanistic and existing schemes against field measurements will be discussed. Our updated framework will help to predict the diurnal and daily variability

  12. Research on process management of nuclear power technological innovation

    International Nuclear Information System (INIS)

    Yang Hua; Zhou Yu

    2005-01-01

    Different from the other technological innovation processes, the technological innovation process of nuclear power engineering project is influenced deeply by the extensive environmental factors, the technological innovation of nuclear power engineering project needs to make an effort to reduce environmental uncertainty. This paper had described the mechanism of connection technological innovation process of nuclear power engineering project with environmental factors, and issued a feasible method based on model of bargaining to incorporate technological innovation process management of nuclear power engineering project with environmental factors. This method has realistic meanings to guide the technological innovation of nuclear power engineering project. (authors)

  13. Studies of works management and automation of nuclear power installations

    International Nuclear Information System (INIS)

    Besch, P.; Grossmann, J.; Hollasky, R.

    1989-01-01

    Erection and operation of nuclear power installations require investigations on their safety and availability. The works performed on the management of nuclear power plants and nuclear heating stations in the Working Group on Automation Engineering of the Dresden University of Technology are presented. Emphasis of the works is on simulation of dynamical performance of the plants and studies on the utilization of novel techniques concerning plant automation and process management. (author)

  14. Management discourse: Talking the power walk in organizational communication

    Directory of Open Access Journals (Sweden)

    Birgitte Norlyk

    2012-08-01

    Full Text Available How does management talk the power walk in organizations? By giving straightforward orders since this is a traditional managerial prerogative which does not require an understanding of the subtleties of discourse and the finer aspects of interpersonal communication? Or should management avoid potentially face-threatening orders and concentrate on subtle and discreet manifestations of power in which discourse becomes an important tool when communicating with internal and external stakeholders?

  15. Management discourse: Talking the power walk in organizational communication

    Directory of Open Access Journals (Sweden)

    Birgitte Norlyk

    2009-08-01

    Full Text Available How does management talk the power walk in organizations? By giving straightforward orders since this is a traditional managerial prerogative which does not require an understanding of the subtleties of discourse and the finer aspects of interpersonal communication? Or should management avoid potentially face-threatening orders and concentrate on subtle and discreet manifestations of power in which discourse becomes an important tool when communicating with internal and external stakeholders?

  16. Active and reactive power sharing and frequency restoration in a distributed power system consisting of two UPS units

    Energy Technology Data Exchange (ETDEWEB)

    Parlak, Koray Sener; Oezdemir, Mehmet [Dept. of Electrical and Electronic Engineering, Firat University, Elazig, 23119 (Turkey); Aydemir, M. Timur [Dept. of Electrical and Electronic Engineering, Gazi University, Maltepe-Ankara 06570 (Turkey)

    2009-06-15

    A distributed power system consisting of two uninterrupted power supplies (UPS) is investigated in this paper. Parallel operation of the two sources increases the established power rating of the system. One of the sources can supply the system even when the other system is disconnected due to some faults, and this is an important feature. The control algorithm makes sure that the total load is shared between the supplies in accordance with their rated power levels, and the frequency of the supplies are restored to the rated values after the transitions. As the UPSs operate at an optimum power level, losses and faults due to overloading are prevented. The units safely operate without any means of communication between each other. The focus of the work is on the inverter stages of the UPSs. Simulations performed in Matlab Simulink environment have been verified with experimental work via DS1103 controller card. (author)

  17. Water management and reuse opportunities in a thermal power ...

    African Journals Online (AJOL)

    The Rehab power plant located in the Northern part of Jordan is presented as a case study of industrial water management. This power plant consumes boiler feed water in the amount of 200 m3/d of the fresh ground water available from nearby wells and it produces 193 m3/d of wastewater. Fifty seven water samples were ...

  18. Power Admission Control with Predictive Thermal Management in Smart Buildings

    DEFF Research Database (Denmark)

    Yao, Jianguo; Costanzo, Giuseppe Tommaso; Zhu, Guchuan

    2015-01-01

    This paper presents a control scheme for thermal management in smart buildings based on predictive power admission control. This approach combines model predictive control with budget-schedulability analysis in order to reduce peak power consumption as well as ensure thermal comfort. First...

  19. Management of radioactive wastes at nuclear power plants

    International Nuclear Information System (INIS)

    2008-03-01

    This Regulation refers to the requirements of the Regulation CNEN-NE.1.26, 'Safety Operation of Nuclear Power Plants', as expressed in the section 13, specifically in the subsection 13.4, relatives to the management of radioactive wastes at nuclear power plants

  20. Knowledge management for the decommissioning of nuclear power plants

    International Nuclear Information System (INIS)

    Kirschnick, F.; Engelhardt, S.

    2004-01-01

    This paper describes background, objectives and select conceptual components of knowledge management for the decommissioning of nuclear power plants. The concept focuses on the transfer of personal practice experience within and between nuclear power plants. The conceptual insights embrace aspects of knowledge content, structure, KM processes, organization, cooperation, culture, persuasion, leadership, technology, infrastructure, business impact and resilience. Key challenges are discussed, and related advice is provided for KM practitioners with similar endeavours in the field of nuclear power plant decommissioning. (author)

  1. On Power Refueling Management of HTR-PM

    International Nuclear Information System (INIS)

    Sun Furui; Luo Yong; Gao Qiang

    2014-01-01

    The refueling management is an important work of nuclear power plant , directly affecting its safety and economy. At present, the ordinary commercial pressurized water reactor (PWR) nuclear power plant has developed more mature in the refueling management, and formed a set of relatively complete system and methods.The High Temperature Gas-cooled Reactor Pebble-modules Demonstration Project(HTR-PM) has significant differences with the ordinary PWR nuclear power plant in the fuel morphology and the refueling mode. It adopts the spherical fuel element and the on-power refueling. Therefore, the HTR-PM refueling management has its own unique characteristics, but currently there is no mature experience to use for reference across the world. This paper gives a brief introduction to the HTR-PM on power refueling management, including the refueling management system construction, the refueling strategy, the fuel element internal transportation,charging and discharging, etc. It aims at finding the befitting HTR-PM refueling management methods in view of its own unique characteristics in order to ensure the orderly development of the refueling management and the refueling safety. (author)

  2. The role of NOSA five-star management system for occupational management of nuclear power plants

    International Nuclear Information System (INIS)

    Zhang Qin

    2011-01-01

    The occupational safety management of nuclear power plant is developed towards integrated management, risk management, process management, all-round and full staff participation. Appropriate management method integrated with nuclear power plant safety, health and environmental protection could be organically combined with the nuclear safety operation management system, and could jointly lay a solid foundation for building up good nuclear safety culture. NOSA five-star management system is such a kind of risk management based on safety, health and environmental management system, with an aim to protect the personal safety. The concepts of NOSA management and nuclear safety culture are coincident, with strong workability, and meeting the need of nuclear power plant occupational safety management. Adopting NOSA five-star management system and keeping continuous improvement is one of the effective ways to improve the level of occupational safety management of nuclear power plant. It can be organically combined with nuclear safety operation management system and continuously improved safety culture to play an important role in improving the safety and economics of nuclear power plant. (author)

  3. High performance monolithic power management system with dynamic maximum power point tracking for microbial fuel cells.

    Science.gov (United States)

    Erbay, Celal; Carreon-Bautista, Salvador; Sanchez-Sinencio, Edgar; Han, Arum

    2014-12-02

    Microbial fuel cell (MFC) that can directly generate electricity from organic waste or biomass is a promising renewable and clean technology. However, low power and low voltage output of MFCs typically do not allow directly operating most electrical applications, whether it is supplementing electricity to wastewater treatment plants or for powering autonomous wireless sensor networks. Power management systems (PMSs) can overcome this limitation by boosting the MFC output voltage and managing the power for maximum efficiency. We present a monolithic low-power-consuming PMS integrated circuit (IC) chip capable of dynamic maximum power point tracking (MPPT) to maximize the extracted power from MFCs, regardless of the power and voltage fluctuations from MFCs over time. The proposed PMS continuously detects the maximum power point (MPP) of the MFC and matches the load impedance of the PMS for maximum efficiency. The system also operates autonomously by directly drawing power from the MFC itself without any external power. The overall system efficiency, defined as the ratio between input energy from the MFC and output energy stored into the supercapacitor of the PMS, was 30%. As a demonstration, the PMS connected to a 240 mL two-chamber MFC (generating 0.4 V and 512 μW at MPP) successfully powered a wireless temperature sensor that requires a voltage of 2.5 V and consumes power of 85 mW each time it transmit the sensor data, and successfully transmitted a sensor reading every 7.5 min. The PMS also efficiently managed the power output of a lower-power producing MFC, demonstrating that the PMS works efficiently at various MFC power output level.

  4. A computerized total-radiation management system for Shikoku Electric Power's Ikata nuclear-power plant

    International Nuclear Information System (INIS)

    Hirao, Toshiyuki; Sakakihara, Tetsuro; Tanabe, Shozo; Kano, Mamoru; Hoshi, Jun-ichi.

    1985-01-01

    This system allows on-line, real-time radiation management at nuclear-power plants. It increases management precision, decreases management workloads, and saves labor in operations that previously required specialized technicians to expend great amounts of time and effort on radiation management at facilities and their environments, environmental radiation evaluation, and control of radioactive waste. The article outlines the already installed system. (author)

  5. Fast Reactive Power Sharing, Circulating Current and Resonance Suppression for Parallel Inverters Using Resistive-Capacitive Output Impedance

    DEFF Research Database (Denmark)

    Chen, Yandong; Guerrero, Josep M.; Shuai, Zhikang

    2016-01-01

    In this paper, an inverter using resistivecapacitive output impedance (RC-type inverter) is proposed not only to provide fast reactive power sharing to support microgrid voltage, and but also to reduce circulating currents and damp high-frequency resonances among inverters. Introducing the RC......-frequency resonances among parallel inverters are quantitatively analyzed. The control parameters are systematically selected, and effect of virtual complex impedance on the inverter output voltage is depicted. The RC-type inverter can reduce circulating currents and damp resonances due to different equivalent output...

  6. Coordinated control of active and reactive power of distribution network with distributed PV cluster via model predictive control

    Science.gov (United States)

    Ji, Yu; Sheng, Wanxing; Jin, Wei; Wu, Ming; Liu, Haitao; Chen, Feng

    2018-02-01

    A coordinated optimal control method of active and reactive power of distribution network with distributed PV cluster based on model predictive control is proposed in this paper. The method divides the control process into long-time scale optimal control and short-time scale optimal control with multi-step optimization. The models are transformed into a second-order cone programming problem due to the non-convex and nonlinear of the optimal models which are hard to be solved. An improved IEEE 33-bus distribution network system is used to analyse the feasibility and the effectiveness of the proposed control method

  7. Design of reactive power regulator of synchronous generators by considering grid impedance angle for characteristic index objectives

    DEFF Research Database (Denmark)

    Raboni, Pietro; Chaudhary, Sanjay K.; Chen, Zhe

    2016-01-01

    functions are formulated on the basis of the integral of an error. This difference makes them suitable for the cases where the entire step-response data series are unavailable. The performances of differently tuned regulators are compared considering a test system including a 100 kW Diesel Generator Set......Effects of low reactance to resistance ratio in distribution networks are widely studied but little work dealing with the tuning of voltage and reactive power regulators of small synchronous generators has been reported. This study endeavours the design of a proportional integral controller...

  8. Valves maintenance management in nuclear power plants

    International Nuclear Information System (INIS)

    Trost, J.

    2001-01-01

    The deregulation of Europe's power market will force nuclear power plant operators to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing expenditure on maintenance. Framatome ANP GmbH, in cooperation with plant operators is currently developing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. (Author)

  9. Market architecture and power demand management

    International Nuclear Information System (INIS)

    Rious, Vincent; Roques, Fabien

    2014-12-01

    Demand response is a cornerstone problem in electricity markets considering climate change constraint. Most liberalized electricity markets have a poor track record at developing demand response. In Europe, different models are considered for demand response, from a development under a regulated regime to a development under competitive perspectives. In this paper, focusing on demand response for mid-size and small consumers, we investigate which types of market signals should be sent to demand response aggregators to see demand response emerge as a competitive activity. Using data from the French power system over eight years, we compare the possible market design options to allow demand response to develop. Our simulations demonstrate that with the current market rules, demand response is not a profitable activity in the French electricity industry. Introducing a capacity remuneration could bring additional revenues to demand response aggregators if the power system has no over-capacity

  10. Measurement of reactivity temperature coefficient by noise method in a power reactor

    International Nuclear Information System (INIS)

    Aguilar, O.

    1986-07-01

    The temperature reactivity coefficient was estimated on the basis of noise measurements performed in a PWR. The magnitude of the coefficient was evaluated by relating the values of the APSD and CPSD between ex-core neutron detector signals and fuel assembly outlet thermocouple in the low frequency range. Comparison with δρ/δT measurements performed in PWR by standard methods supports the validity of the results. (author)

  11. Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory; Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Westerberg, Emil [Dalarna Univ., Borlaenge (Sweden). Graphic Art Technology

    2002-12-01

    This report describes the work that is being conducted on power management controls at Berkeley National Laboratory. We can see a significant increasing amount of electronic equipment in our work places and in our every day life. Today's modern society depends on a constant energy flow. The future's increasing need of energy will burden our economy as well as our environment. The project group at Berkeley National Laboratory is working with leading manufacturers of office equipment. The goal is to agree on how interfaces for power management should be presented on office equipment. User friendliness and a more consistent power management interface is the project focus. The project group's role is to analyze data that is relevant to power management, as well as to coordinate communication and discussions among the involved parties.

  12. Power/Knowledge in Natural Resource Management

    NARCIS (Netherlands)

    Duineveld, Martijn; Van Assche, Kristof; Beunen, R.

    2017-01-01

    This special issue of Journal of Environmental Policy & Planning draws the attention to ongoing concerns about the management of natural resources (NRM): their exploration, extraction, processing, and commodification is still happening in ways that are perceived to be socially unjust and

  13. Principles of power frequency magnetic field management

    International Nuclear Information System (INIS)

    Fugate, D.; Feero, W.

    1995-01-01

    At the most general level, magnetic field management is the creation, elimination, or modification of sources in order to alter the spatial distribution of magnetic fields over some region of space. The two main options for magnetic field management are source modification (elimination or modification of original sources) and cancellation (creation of new sources). Source modification includes any changes in the layout or location of field sources, elimination of ground paths, or any options that increase the distance between sources and regions of interest. Cancellation involves the creation of new magnetic field sources, passive and/or active that produce magnetic fields that are opposite to the original fields in the region of interest. Shielding using materials of high conductivity and/or high permeability falls under the cancellation option. Strategies for magnetic field management, whether they are source modification or cancellation, typically vary on a case to case basis depending on the regions of interest, the types of sources and resulting complexity of the field structure, the field levels, and the attenuation requirements. This paper gives an overview of magnetic field management based on fundamental concepts. Low field design principles are described, followed by a structured discussion of cancellation and shielding. The two basic material shielding mechanisms, induced current shielding, and flux-shunting are discussed

  14. Management of radioactive waste nuclear power plants

    International Nuclear Information System (INIS)

    Dlouhy, Z.; Marek, J.

    1976-01-01

    The authors give a survey of the sources, types and amounts of radioactive waste in LWR nuclear power stations (1,300 MWe). The amount of solid waste produced by a Novovorenezh-type PWR reactor (2 x 400 resp. 1 x 1,000 MWe) is given in a table. Treatment, solidification and final storage of radioactive waste are shortly discussed with special reference to the problems of final storage in the CSR. (HR) [de

  15. Viewpoint of utilities regarding fuel management of nuclear power plants

    International Nuclear Information System (INIS)

    Held, C.; Moraw, G.; Schneeberger, M.; Szeless, A.

    1977-01-01

    The engagement of utilities in nuclear power requires them to engage in an increasing amount of fuel management activities in order to carry out all the tasks involved. Essentially, these activities involve two main areas: The procurement of all steps of the fuel cycle from the head to the back end; and in-core fuel management. A general survey of the different steps of the nuclear fuel cycle is presented together with the related activities and responsibilities which have to be borne by the utilities. Today's increasing utility involvement in the nuclear fuel management is shown, as well as future fuel management trends. The fuel management activities of the utilities are analysed with respect to organizational, technical, safeguarding, and financial aspects. The active participation of the utilities in fuel management helps to achieve high availability and flexibility of the nuclear power plant during its whole life as well as safe waste isolation. This can be ensured by continuous optimization of all fuel management aspects of the power plant or, on a larger scale, of a power plant system, i.e. activities by utilities to minimize fuel-cycle effects on the environment, which include optimization of fuel behaviour, and radiation exposure to the public and personnel; and technical and economic evaluations by utilities of out- and in-core fuel management. (author)

  16. Risk management of power supply in open electricity market

    International Nuclear Information System (INIS)

    Rinta-Runsala, E.; Kiviniemi, J.

    1999-12-01

    The open electricity market has increased the need of risk management in electric utilities. In this publication the concepts of risk assessment and measures mostly concentrating on market risks for power supply companies are reported. An essential past of the risk management includes the electricity derivates and trade

  17. Management of the Tobruk power station and seawater desalination plant

    Energy Technology Data Exchange (ETDEWEB)

    Homann, H J

    1983-01-01

    BBC and two consortium firms provided, for one year, the management personnel for operation and maintenance of the power and seawater desalination plant in Tobruk, Libya, constructed under the leadership of BBC. The plant organisation was established at site in cooperation with the client. Following thorough training, the client's staff took over plant management after one year according to contract.

  18. Medlay: A Reconfigurable Micro-Power Management to Investigate Self-Powered Systems

    Directory of Open Access Journals (Sweden)

    Jan Kokert

    2018-01-01

    Full Text Available In self-powered microsystems, a power management is essential to extract, transfer and regulate power from energy harvesting sources to loads such as sensors. The challenge is to consider all of the different structures and components available and build the optimal power management on a microscale. The purpose of this paper is to streamline the design process by creating a novel reconfigurable testbed called Medlay. First, we propose a uniform interface for management functions e.g., power conversion, energy storing and power routing. This interface results in a clear layout because power and status pins are strictly separated, and inputs and outputs have fixed positions. Medlay is the ready-to-use and open-hardware platform based on the interface. It consists of a base board and small modules incorporating e.g., dc-dc converters, power switches and supercapacitors. Measurements confirm that Medlay represents a system on one circuit board, as parasitic effects of the interconnections are negligible. The versatility regarding different setups on the testbed is determined to over 250,000 combinations by layout graph grammar. Lastly, we underline the applicability by recreating three state-of-the-art systems with the testbed. In conclusion, Medlay facilitates building and testing power management in a very compact, clear and extensible fashion.

  19. Implementation of New Reactivity Measurement System and New Reactor Noise Analysis Equipment in a VVER-440 Nuclear Power Plant

    Science.gov (United States)

    Vegh, János; Kiss, Sándor; Lipcsei, Sándor; Horvath, Csaba; Pos, István; Kiss, Gábor

    2010-10-01

    The paper deals with two recently developed, high-precision nuclear measurement systems installed at the VVER-440 units of the Hungarian Paks NPP. Both developments were motivated by the reactor power increase to 108%, and by the planned plant service time extension. The first part describes the RMR start-up reactivity measurement system with advanced services. High-precision picoampere meters were installed at each reactor unit and measured ionization chamber current signals are handled by a portable computer providing data acquisition and online reactivity calculation service. Detailed offline evaluation and analysis of reactor start-up measurements can be performed on the portable unit, too. The second part of the paper describes a new reactor noise diagnostics system using state-of-the-art data acquisition hardware and signal processing methods. Details of the new reactor noise measurement evaluation software are also outlined. Noise diagnostics at Paks NPP is a standard tool for core anomaly detection and for long-term noise trend monitoring. Regular application of these systems is illustrated by real plant data, e.g., results of standard reactivity measurements during a reactor startup session are given. Noise applications are also illustrated by real plant measurements; results of core anomaly detection are presented.

  20. Risk management: A tool for improving nuclear power plant performance

    International Nuclear Information System (INIS)

    2001-04-01

    This technical document on risk management as a tool for improving nuclear power plant (NPP) operations is part of an ongoing project on management of NPP operations in a competitive environment. The overall objective of this project is to assist the management of operating organizations and NPPs in identifying and implementing appropriate measures to remain competitive in a rapidly changing business environment. Other reports developed through this project have identified overall strategies and techniques that NPP operating organization managers can use to succeed in more competitive energy markets. For example, in IAEA-TECDOC-1123, Strategies for Competitive Nuclear Power Plants, one of the most important strategies identified was integrated risk management. This publication provides a recommended structure for risk management along with examples of how NPP operating organizations are using this tool to help them integrate safety, operational and economic related risks in a changing business environment

  1. Investigation of Reactive Power Control Effects on Flicker and Harmonics Emission of a DFIG Wind Turbine

    OpenAIRE

    Amir Nagizadeh Ghoogdareh; Aref Doroudi; Mohammad Poormonfared Azimi

    2013-01-01

    One of the most important power quality aspects in wind farms is voltage fluctuation or flicker which should be investigated due to the nature of wind speed variations. These variations result in power and voltage fluctuations at the load bus. Moreover, the wind generation systems may be assumed as a harmonics source because of their power electronic converters. There are numerous factors that affect flicker and harmonic emission of grid-connected wind turbines during continuous operation, su...

  2. Power management circuits for self-powered systems based on micro-scale solar energy harvesting

    Science.gov (United States)

    Yoon, Eun-Jung; Yu, Chong-Gun

    2016-03-01

    In this paper, two types of power management circuits for self-powered systems based on micro-scale solar energy harvesting are proposed. First, if a solar cell outputs a very low voltage, less than 0.5 V, as in miniature solar cells or monolithic integrated solar cells, such that it cannot directly power the load, a voltage booster is employed to step up the solar cell's output voltage, and then a power management unit (PMU) delivers the boosted voltage to the load. Second, if the output voltage of a solar cell is enough to drive the load, the PMU directly supplies the load with solar energy. The proposed power management systems are designed and fabricated in a 0.18-μm complementary metal-oxide-semiconductor process, and their performances are compared and analysed through measurements.

  3. Quality management in an international nuclear power plant project

    International Nuclear Information System (INIS)

    Brion, J.; Crustin, J.

    1975-01-01

    SNR (Schneller Natriumgekuehlter Reaktor) is the fast reactor power plant being erected at Kalkar, Federal German Republic. Quality management in this project is a contractual obligation. Quality management is subdivided into quality engineering, set of actions performed before manufacturing, and quality control, set of material controls performed during fabrication. The two successive phases of the quality management are presented. The difficulties and improvment possibilities are discussed [fr

  4. South African Regulatory Framework for Nuclear Power Plant Life Management

    International Nuclear Information System (INIS)

    Mbebe, B.Z.

    2012-01-01

    The paper presents the regulatory approach to plant life management (PLiM) adopted by the National Nuclear Regulator (NNR) in South Africa, the licensing basis and regulatory requirements for Koeberg Nuclear Power Station (KNPS),operational programmes ensuring continued safe operation, issues related to the ageing of the plant, and the requirements for spent fuel as well as radioactive waste management. The paper will further present insights from the Periodic Safety Review (PSR) and Long Term Asset Management. (author)

  5. Technical support and management systems for nuclear power stations

    International Nuclear Information System (INIS)

    Oya, Tadashi; Abe, Norihiko

    1990-01-01

    Sophisticated automatic monitoring and control capabilities and computerized operation management are needed in nuclear power plants to boost plant safety and availability and to reduce operating costs. The article covers the areas of operation management and maintenance management within the larger category of operational administration. The concept of technical administration support-that is, the use of computerization to support the on-site technician's operations-is introduced. The article also suggests the direction of future development. (author)

  6. Power Management Integrated Circuit for Indoor Photovoltaic Energy Harvesting System

    Science.gov (United States)

    Jain, Vipul

    In today's world, power dissipation is a main concern for battery operated mobile devices. Key design decisions are being governed by power rather than area/delay because power requirements are growing more stringent every year. Hence, a hybrid power management system is proposed, which uses both a solar panel to harvest energy from indoor lighting and a battery to power the load. The system tracks the maximum power point of the solar panel and regulates the battery and microcontroller output load voltages through the use of an on-chip switched-capacitor DC-DC converter. System performance is verified through simulation at the 180nm technology node and is made to be integrated on-chip with 0.25 second startup time, 79% efficiency, --8/+14% ripple on the load, an average 1micro A of quiescent current (3.7micro W of power) and total on-chip area of 1.8mm2 .

  7. Management of National Nuclear Power Programs for assured safety

    International Nuclear Information System (INIS)

    Connolly, T.J.

    1985-01-01

    Topics discussed in this report include: nuclear utility organization; before the Florida Public Service Commission in re: St. Lucie Unit No. 2 cost recovery; nuclear reliability improvement and safety operations; nuclear utility management; training of nuclear facility personnel; US experience in key areas of nuclear safety; the US Nuclear Regulatory Commission - function and process; regulatory considerations of the risk of nuclear power plants; overview of the processes of reliability and risk management; management significance of risk analysis; international and domestic institutional issues for peaceful nuclear uses; the role of the Institute of Nuclear Power Operations (INPO); and nuclear safety activities of the International Atomic Energy Agency (IAEA)

  8. Management of National Nuclear Power Programs for assured safety

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, T.J. (ed.)

    1985-01-01

    Topics discussed in this report include: nuclear utility organization; before the Florida Public Service Commission in re: St. Lucie Unit No. 2 cost recovery; nuclear reliability improvement and safety operations; nuclear utility management; training of nuclear facility personnel; US experience in key areas of nuclear safety; the US Nuclear Regulatory Commission - function and process; regulatory considerations of the risk of nuclear power plants; overview of the processes of reliability and risk management; management significance of risk analysis; international and domestic institutional issues for peaceful nuclear uses; the role of the Institute of Nuclear Power Operations (INPO); and nuclear safety activities of the International Atomic Energy Agency (IAEA).

  9. Generating optimized stochastic power management strategies for electric car components

    Energy Technology Data Exchange (ETDEWEB)

    Fruth, Matthias [TraceTronic GmbH, Dresden (Germany); Bastian, Steve [Technische Univ. Dresden (Germany)

    2012-11-01

    With the increasing prevalence of electric vehicles, reducing the power consumption of car components becomes a necessity. For the example of a novel traffic-light assistance system, which makes speed recommendations based on the expected length of red-light phases, power-management strategies are used to control under which conditions radio communication, positioning systems and other components are switched to low-power (e.g. sleep) or high-power (e.g. idle/busy) states. We apply dynamic power management, an optimization technique well-known from other domains, in order to compute energy-optimal power-management strategies, sometimes resulting in these strategies being stochastic. On the example of the traffic-light assistant, we present a MATLAB/Simulink-implemented framework for the generation, simulation and formal analysis of optimized power-management strategies, which is based on this technique. We study capabilities and limitations of this approach and sketch further applications in the automotive domain. (orig.)

  10. Texas Instruments Technical Seminar: Power Management and Wireless

    CERN Multimedia

    2006-01-01

    Monday 6 November TECHNICAL TRAINING SEMINAR 14:00 to 17:30 - Training Centre Auditorium (bldg. 593) Texas Instruments Technical Seminar: Power Management and Wireless Michael Scholtholt, Field Application Engineer / TEXAS INSTRUMENTS (US, D, CH) The range of power management products available today offers the possibility to find the best solution for each application. To select the right product it is therefore necessary to understand system requirements, how power supply products work, and where they differentiate. This Technical Training Seminar will also present an overview of how to choose the right RF platform based on markets and applications: nowadays almost everbody has at least one wireless product in use, and this tendency seems to increase significantly. Power Management Voltage mode vs. current mode control Differentiating DC/DC converters by analyzing control and compensation schemes: line / load regulation, transient response, BOM, board space, ease-of-use Introduction to evaluati...

  11. Texas Instruments Technical Seminar: Power Management and Wireless

    CERN Multimedia

    2006-01-01

    Monday 6 November TECHNICAL TRAINING SEMINAR 14:00 to 17:30 - Training Centre Auditorium (bldg. 593) Texas Instruments Technical Seminar: Power Management and Wireless Michael Scholtholt, Field Application Engineer / TEXAS INSTRUMENTS (US, D, CH) The range of power management products available today offers the possibility to find the best solution for each application. To select the right product it is therefore necessary to understand system requirements, how power supply products work, and where they differentiate. This Technical Training Seminar will also present an overview of how to choose the right RF platform based on markets and applications: nowadays almost everbody has at least one wireless product in use, and this tendency seems to increase significantly. Power Management Voltage mode vs. current mode control Differentiating DC/DC converters by analyzing control and compensation schemes: line / load regulation, transient response, BOM, board space, ease-of-use Introduction to evalu...

  12. Waste management at the Ardennes power plant

    International Nuclear Information System (INIS)

    Abraham, J.P.

    1979-01-01

    In 1976, the SENA (with the participation of EDF, CEA and CEC in the framework of a research program on the management and storage of radioactive wastes) has developed an industrial pilot plant for the encapsulation of wastes in thermosetting polyester resins. The industrial putting in operation of the plant will enable most of the wastes from the nuclear station to be processed. The quality of products will be improved and the volume and processing cost reduced

  13. Evaluation of power control concepts using the PMAD systems test bed. [Power Management and Distribution

    Science.gov (United States)

    Beach, R. F.; Kimnach, G. L.; Jett, T. A.; Trash, L. M.

    1989-01-01

    The Lewis Research Center's Power Management and Distribution (PMAD) System testbed and its use in the evaluation of control concepts applicable to the NASA Space Station Freedom electric power system (EPS) are described. The facility was constructed to allow testing of control hardware and software in an environment functionally similar to the space station electric power system. Control hardware and software have been developed to allow operation of the testbed power system in a manner similar to a supervisory control and data acquisition (SCADA) system employed by utility power systems for control. The system hardware and software are described.

  14. Research on reliability management systems for Nuclear Power Plant

    International Nuclear Information System (INIS)

    Maki, Nobuo

    2000-01-01

    Investigation on a reliability management system for Nuclear Power Plants (NPPs) has been performed on national and international archived documents as well as on current status of studies at Idaho National Engineering and Environmental Laboratory (INEEL), US NPPs (McGuire, Seabrook), a French NPP (St. Laurent-des-Eaux), Japan Atomic Energy Research Institute (JAERI), Central Research Institute of Electric Power Industries (CRIEPI), and power plant manufacturers in Japan. As a result of the investigation, the following points were identified: (i) A reliability management system is composed of a maintenance management system to inclusively manage maintenance data, and an anomalies information and reliability data management system to extract data from maintenance results stored in the maintenance management system and construct a reliability database. (ii) The maintenance management system, which is widely-used among NPPs in the US and Europe, is an indispensable system for the increase of maintenance reliability. (iii) Maintenance management methods utilizing reliability data like Reliability Centered Maintenance are applied for NPP maintenance in the US and Europe, and contributing to cost saving. Maintenance templates are effective in the application process. In addition, the following points were proposed on the design of the system: (i) A detailed database on specifications of facilities and components is necessary for the effective use of the system. (ii) A demand database is indispensable for the application of the methods. (iii) Full-time database managers are important to maintain the quality of the reliability data. (author)

  15. Study of solar array switching power management technology for space power system

    Science.gov (United States)

    Cassinelli, J. E.

    1982-01-01

    This report documents work performed on the Solar Array Switching Power Management Study. Mission characteristics for three missions were defined to the depth necessary to determine their power management requirements. Solar array switching concepts which could satisfy the mission requirements were identified. The switching concepts were compared with a conventional buck regulator system for cost, weight and volume, reliability, efficiency and thermal control. Solar array switching provided significant advantages in all areas of comparison for the reviewed missions.

  16. Lifetime management research trend of Kori-1 nuclear power plant

    International Nuclear Information System (INIS)

    Kim, J. S.; Jeong, I. S.; Hong, S. Y.

    1998-01-01

    KEPRI launched the Nuclear Power Plant Lifetime Management Study(II) for the management of the latter half life of Kori-1. Main goal of LCM-IV study is the detail evaluation of main equipment life and establishment of aging management based on LCM-IV result. The result of LCM-IV on the kori-1 confirmed the technical and economical feasibility of life extension beyond the design life. Owing to absence of The regulatory policy for the life extension in korea, LCM-IV will focus on the minimum study which is essential for the actual lifetime management for the old nuclear power plant. License renewal study is expected after the establishment of Regulatory policy about the life extension of nuclear power plant. LCM trend in korea and abroad, result of technical and economical feasibility study and summary of LCM-IV is described on this paper

  17. Planning and Resource Management in an Intelligent Automated Power Management System

    Science.gov (United States)

    Morris, Robert A.

    1991-01-01

    Power system management is a process of guiding a power system towards the objective of continuous supply of electrical power to a set of loads. Spacecraft power system management requires planning and scheduling, since electrical power is a scarce resource in space. The automation of power system management for future spacecraft has been recognized as an important R&D goal. Several automation technologies have emerged including the use of expert systems for automating human problem solving capabilities such as rule based expert system for fault diagnosis and load scheduling. It is questionable whether current generation expert system technology is applicable for power system management in space. The objective of the ADEPTS (ADvanced Electrical Power management Techniques for Space systems) is to study new techniques for power management automation. These techniques involve integrating current expert system technology with that of parallel and distributed computing, as well as a distributed, object-oriented approach to software design. The focus of the current study is the integration of new procedures for automatically planning and scheduling loads with procedures for performing fault diagnosis and control. The objective is the concurrent execution of both sets of tasks on separate transputer processors, thus adding parallelism to the overall management process.

  18. Optimal reactive power and voltage control in distribution networks with distributed generators by fuzzy adaptive hybrid particle swarm optimisation method

    DEFF Research Database (Denmark)

    Chen, Shuheng; Hu, Weihao; Su, Chi

    2015-01-01

    A new and efficient methodology for optimal reactive power and voltage control of distribution networks with distributed generators based on fuzzy adaptive hybrid PSO (FAHPSO) is proposed. The objective is to minimize comprehensive cost, consisting of power loss and operation cost of transformers...... that the proposed method can search a more promising control schedule of all transformers, all capacitors and all distributed generators with less time consumption, compared with other listed artificial intelligent methods....... algorithm is implemented in VC++ 6.0 program language and the corresponding numerical experiments are finished on the modified version of the IEEE 33-node distribution system with two newly installed distributed generators and eight newly installed capacitors banks. The numerical results prove...

  19. Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hänninen, Tuomas, E-mail: tuoha@ifm.liu.se; Schmidt, Susann; Jensen, Jens; Hultman, Lars; Högberg, Hans [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden)

    2015-09-15

    Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.

  20. A global plasma model for reactive deposition of compound films by modulated pulsed power magnetron sputtering discharges

    Science.gov (United States)

    Zheng, B. C.; Wu, Z. L.; Wu, B.; Li, Y. G.; Lei, M. K.

    2017-05-01

    A spatially averaged, time-dependent global plasma model has been developed to describe the reactive deposition of a TiAlSiN thin film by modulated pulsed power magnetron sputtering (MPPMS) discharges in Ar/N2 mixture gas, based on the particle balance and the energy balance in the ionization region, and considering the formation and erosion of the compound at the target surface. The modeling results show that, with increasing the N2 partial pressure from 0% to 40% at a constant working pressure of 0.3 Pa, the electron temperature during the strongly ionized period increases from 4 to 7 eV and the effective power transfer coefficient, which represents the power fraction that effectively heats the electrons and maintains the discharge, increases from about 4% to 7%; with increasing the working pressure from 0.1 to 0.7 Pa at a constant N2 partial pressure of 25%, the electron temperature decreases from 10 to 4 eV and the effective power transfer coefficient decreases from 8% to 5%. Using the modeled plasma parameters to evaluate the kinetic energy of arriving ions, the ion-to-neutral flux ratio of deposited species, and the substrate heating, the variations of process parameters that increase these values lead to an enhanced adatom mobility at the target surface and an increased input energy to the substrate, corresponding to the experimental observation of surface roughness reduction, the microstructure transition from the columnar structure to the dense featureless structure, and the enhancement of phase separation. At higher N2 partial pressure or lower working pressure, the modeling results demonstrate an increase in electron temperature, which shifts the discharge balance of Ti species from Ti+ to Ti2+ and results in a higher return fraction of Ti species, corresponding to the higher Al/Ti ratio of deposited films at these conditions. The modeling results are well correlated with the experimental observation of the composition variation and the microstructure

  1. Development of management systems for nuclear power plant of Hokuriku Electric Power Company

    International Nuclear Information System (INIS)

    Nakamura, Tatsuaki; Hasunuma, Junichi; Suzuki, Shintaro

    2009-01-01

    Hokuriku Electric Power Company has been operating the Shika Nuclear Power Station that it constructed in Shika city, Ishikawa prefecture, for over 15 years since bringing Unit 1 of this plant online in July 1993. In addition to electricity generation, maintenance and inspection tasks constitute a big part of operating a large-scale nuclear power plant, and in recent years, problems at power stations in the nuclear power industry have led to several revisions of nationally regulated maintenance and inspection systems. This paper describes the background, objectives, development method, and features of the Maintenance Management System and Maintenance History Management System that make effective use of information technology to promote safer and more efficient maintenance work at large-scale nuclear power plants. (author)

  2. Managing human resources in the nuclear power industry: Lessons learned

    International Nuclear Information System (INIS)

    2003-08-01

    This report is intended for senior and middle level managers in nuclear operating organizations. Its objectives are to facilitate the recognition of priority issues with respect to managing human resources, and to provide pragmatic ideas regarding improvements. The human resource issues addressed in this report, if not managed effectively, can result in significant performance problems at nuclear power plants. About 10 years ago the IAEA initiated an effort to identify such management issues and to find effective practices to deal with them. This information was provided in IAEA Technical Reports Series No. 369, Management for Excellence in Nuclear Power Plant Performance - A Manual (1994). This report builds upon the information in the subject manual. In the past 10 years there have been significant changes in the nuclear power industry resulting primarily from more competitive energy markets and privatization of nuclear power plant operating organizations. In general, the industry has responded positively to these changes, as indicated by IAEA/WANO performance indicators that show both improved operational and safety performance. This report provides examples of approaches to managing human resources that have been effective in responding to these changes. This report was produced through a series of meetings, where meeting participants were asked to share information regarding effective practices in their organizations with respect to managing human resources. The information provided through these meetings was supplemented with good practices in this area identified through IAEA Operational Safety Review Teams (OSARTs) conducted during the past 10 years

  3. Active and reactive power control schemes for distributed generation systems under voltage dips

    NARCIS (Netherlands)

    Wang, F.; Duarte, J.L.; Hendrix, M.A.M.

    2009-01-01

    During voltage dips continuous power delivery from distributed generation systems to the grid is desirable for the purpose of grid support. In order to facilitate the control of distributed generation systems adapted to the expected change of grid requirements, generalized power control schemes

  4. Quality management for nuclear power plants in Germany. Track 1

    International Nuclear Information System (INIS)

    Dieter, Brosche; Ehrnsperger, K.

    2001-01-01

    An essential requirement for the safety of nuclear power plants is the quality assurance which for example is fixed also in the German safety criteria for nuclear power plants as the first principle of prime importance and also fixed in the technical rules for nuclear power plants. Quality assurance must be performed in all phases of the lifetime of a nuclear power plant and also all partners for example suppliers, operators, experts and authorities are involved in the quality assurance process. All activities in connection with quality assurance are summarized in an integrated quality assurance system or quality assurance management. (author)

  5. Utilities' view on the fuel management of nuclear power plants

    International Nuclear Information System (INIS)

    Held, C.; Moraw, G.; Schneeberger, M.; Szeless, A.

    1977-01-01

    Utilities engagement in nuclear power requires an increasing amount of fuel management activities by the utilities in order to meet all tasks involved. These activities comprise essentially two main areas: - activities to secure the procurement of all steps of the fuel cycle from the head to the back end; - activities related to the incore fuel managment. A general survey of the different steps of the nuclear fuel cycle is presented together with the related activities and responsibilities which have to be realized by the utilities. Starting in the past, today's increasing utility involvement in the nuclear fuel management is shown, as well as future fuel management trends. The scope of utilities' fuel management activities is analyzed with respect to organizational aspects, technical aspects, safeguarding aspects, and financial aspects. Utilities taking active part in the fuel management serves to achieve high availability and flexibility of the nuclear power plant during the whole plant life as well as safe waste isolation. This can be assured by continuous optimization of all fuel management aspects of the power plant or on a larger scale of a power plant system, i.e., utility activities to minimize the effects of fuel cycle on the environment, which includes optimization of fuel behaviour, radiation exposure to public and personnel, and utility technical and economic evaluations of out- and incore fuel management. These activities of nuclear power producing utilities in the field of nuclear fuel cycle are together with a close cooperation with fuel industry as well as national and international authorities a necessary basis for the further utilization of nuclear power

  6. Effects of anodic potential and chloride ion on overall reactivity in electrochemical reactors designed for solar-powered wastewater treatment.

    Science.gov (United States)

    Cho, Kangwoo; Qu, Yan; Kwon, Daejung; Zhang, Hao; Cid, Clément A; Aryanfar, Asghar; Hoffmann, Michael R

    2014-02-18

    We have investigated electrochemical treatment of real domestic wastewater coupled with simultaneous production of molecular H2 as useful byproduct. The electrolysis cells employ multilayer semiconductor anodes with electroactive bismuth-doped TiO2 functionalities and stainless steel cathodes. DC-powered laboratory-scale electrolysis experiments were performed under static anodic potentials (+2.2 or +3.0 V NHE) using domestic wastewater samples, with added chloride ion in variable concentrations. Greater than 95% reductions in chemical oxygen demand (COD) and ammonium ion were achieved within 6 h. In addition, we experimentally determined a decreasing overall reactivity of reactive chlorine species toward COD with an increasing chloride ion concentration under chlorine radicals (Cl·, Cl2(-)·) generation at +3.0 V NHE. The current efficiency for COD removal was 12% with the lowest specific energy consumption of 96 kWh kgCOD(-1) at the cell voltage of near 4 V in 50 mM chloride. The current efficiency and energy efficiency for H2 generation were calculated to range from 34 to 84% and 14 to 26%, respectively. The hydrogen comprised 35 to 60% by volume of evolved gases. The efficacy of our electrolysis cell was further demonstrated by a 20 L prototype reactor totally powered by a photovoltaic (PV) panel, which was shown to eliminate COD and total coliform bacteria in less than 4 h of treatment.

  7. Nuclear power plant information management system 'NUPIMAS'

    International Nuclear Information System (INIS)

    Matsumoto, M.; Saruyama, I.; Kurokawa, Y.; Kayano, M.; Katto, S.

    1980-01-01

    NUPIMAS is an interactive computer graphic system used for the design of pipings of nuclear power plant and the production of their drawings. Data on piping, duct, cable tray, equipment and building are stored in the computer and the following conversational-mode design works are performed online by means of graphic display, plotter and others: (1) Piping route study and interference check. (2) Modification of piping route and specifications. (3) Semi-automatic design of low-temperature piping supports. As the result of these design works the following drawings and lists are produced and interactively refined by computer: (1) Composite drawings. (2) Piping assembly drawings and shop drawings. (3) Bill of material. (4) Welding procedure instruction. (5) Duct route drawings (Isometric and 3-plane views). (6) Shop and assembly drawings of supports, etc. This system is already in practical use, obtaining good results. (author)

  8. Lifetime management of Magnox power stations

    International Nuclear Information System (INIS)

    Smitton, C.

    1998-01-01

    Magnox Electric, which is, a subsidiary of BNFL, operates six nuclear power plants that have an average age of about 33 years. The procedures developed to maintain the plants and ensure nuclear safety in longer-term operation are reviewed. The technical limit on station lifetimes is expected to be determined by the effect of ageing on major reactor structures where replacement is impractical. Examination of the effect of ageing confirms that the stations are capable of operating to a life of at least 40 years. The economic factors affecting operation are reviewed, recognising the need to sell electricity in a competitive market. Recently Magnox Electric and BNFL have merged and all plant supporting Magnox operations are now within a single integrated company that will provide further opportunities for improved efficiency. (author)

  9. Radwastes management in Qinshan Nuclear power plants

    International Nuclear Information System (INIS)

    Zhou Huan; Ling Kechi; Wang Qingrong; Luo Jingfan

    1987-01-01

    The source terms input used as the basic data for designing the radwaste treatment systems of Qinshan Nuclear Power Plant [300 MW(e)] is presented. The classification of radioactive liquid wastes, off-gases and solid wastes, and their treatment techniques, as well as on-site storage facilities for solid wastes are described. For liquid waste, the method of filtration-evaporation-ion exchange will be used as the main treatment technique. For off-gas, Holdup-decay treatment will be used. For evaporator concentrates, indrumsolidification method with normal domestic portland cement will be used. The assessment of impact of effluents to environment at normal operation of the NPP is also made. The results show that it will be safe for inhabitants nearby during normal operation and it can meet the requirements of national standard ''Regulation of Radiation Protection''

  10. Nuclear power and radioactive waste management

    International Nuclear Information System (INIS)

    Feates, F.S.

    1978-01-01

    The generation of electrical power by nuclear means leads to a very considerable reduction in the quantities of waste which would result from the use of any other fuel. The waste possess particular hazards which diminish with time. They are most dangerous during the first 500 years whilst fission products are decaying; subsequently their toxicity is comparable with that of many industrial chemicals which are currently in widespread use. There is no reason to believe that environmentally satisfactory disposal means cannot be found either on or under the ocean bed or below the surface of the earth. Nevertheless, since so little waste is involved considerable care can be devoted to ensure that whatever disposal method is selected is safe. The standards to be adopted are that any disposal method selected will, even in the worst conceivable situation, not lead to a significant increase in the exposure man already receives due to radioactivity arising from natural sources. (author)

  11. K 4R - Knowledge to the Power of RESTful, Resourceful and Reactive Rules

    Science.gov (United States)

    Amador, Ricardo

    The Web of today clearly answers questions of the form "What is the representation of ...?". The Semantic Web (SW) of tomorrow aims at answering questions of the form "What is the meaning of ...?". It is our stance that in order to realize the full potential of the original concept proposed by Tim Berners-Lee et al. (in Scientific American, May 2001), the SW must also answer, in a meaningful way, questions of a dynamic and active nature, like "What to do if ...?" or "What to do when ...?". Moreover, SW questions of the form "What to do ...?" must be expressed and answered in a declarative, compositional and language agnostic way. It is our (hypo)thesis that formally established concepts, viz. the Web's REST architectural style, declarative SW representation of resources based on Description Logics (e.g., OWL-DL), and Reactive Rules (e.g., "on Event if Condition do Action" -ECA- rules), provide the proper theoretical foundations to achieve this goal. This paper describes our current research proposal, K 4R (pronounced, with an Italian flavor, "Che fare?"), towards achieving a declarative model for expressing (re)active behavior in and for the SW.

  12. THE EVALUATION OF THE EFFECT OF REACTIVE POWER COMPENSATION IN ELECTRIC POWER LOSSES IN ELECTRIC NETWORK OF RAILWAY JUNCTION

    OpenAIRE

    O. I. Bondar; I. L. Bondar

    2009-01-01

    In this work the generalized mathematical model of an electrical network of the electrified railway junction is proposed. An estimation of influence of static var compensators installation on electric power losses in a network is executed on the basis of given model.

  13. Smart Energy Management of Multiple Full Cell Powered Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad S. Alam

    2007-04-23

    In this research project the University of South Alabama research team has been investigating smart energy management and control of multiple fuel cell power sources when subjected to varying demands of electrical and thermal loads together with demands of hydrogen production. This research has focused on finding the optimal schedule of the multiple fuel cell power plants in terms of electric, thermal and hydrogen energy. The optimal schedule is expected to yield the lowest operating cost. Our team is also investigating the possibility of generating hydrogen using photoelectrochemical (PEC) solar cells through finding materials for efficient light harvesting photoanodes. The goal is to develop an efficient and cost effective PEC solar cell system for direct electrolysis of water. In addition, models for hydrogen production, purification, and storage will be developed. The results obtained and the data collected will be then used to develop a smart energy management algorithm whose function is to maximize energy conservation within a managed set of appliances, thereby lowering O/M costs of the Fuel Cell power plant (FCPP), and allowing more hydrogen generation opportunities. The Smart Energy Management and Control (SEMaC) software, developed earlier, controls electrical loads in an individual home to achieve load management objectives such that the total power consumption of a typical residential home remains below the available power generated from a fuel cell. In this project, the research team will leverage the SEMaC algorithm developed earlier to create a neighborhood level control system.

  14. GANGA powerful job submission and management tool

    CERN Document Server

    Maier, Andrew; Mendez Lorenzo, Patricia; Moscicki, Jakub; Lamanna, Massimo; Muraru, Adrian

    2008-01-01

    The computational and storage capability of the Grid are attracting several research communities, also beyond HEP. Ganga is a lightweight Grid job management tool developed at CERN. It is a key component in the distributed Data Analysis for ATLAS and LHCb. Ganga`s open and general framework allows to plug-in applications, which has attracted users from other domains outside HEP. In addition, Ganga interfaces to a variety of Grid and non-Grid backends using the same, simple end-user interface Ganga has already gained widespread use, the incomplete list of applications using Ganga include: Imaging processing and classification (developed by Cambridge Ontology Ltd.), Theoretical physics (Lattice QCD, Feynman-loop evaluation), Bio-informatics (Avian Flu Data Challenge), Geant4 (Monte Carlo package), HEP data analysis (ATLAS, LHCb). All these communities have different goals and requirements and the main challenge is the creation of a standard and general software infrastructure for the immersion of these communit...

  15. Selection, competency development and assessment of nuclear power plant managers

    International Nuclear Information System (INIS)

    1998-06-01

    This publication provides information on proven methods and good practices with respect to the selection, development and assessment of nuclear power plant (NPP) managers. The report is organized into four sections, a glossary, two appendices, and several annexes. The Introduction (Section 1) provides the framework for the report. Section 2 describes how appropriate management competencies can be used for the selection, development and assessment of NPP managers, including: -Selection which includes recruitment, promotion and succession management. -Management development programmes including formal training, job rotation, on the job training, mentoring, and outside assignments. -Assessment of individual performance. Section 3 describes a systematic process for identifying the competencies needed by NPP managers. This section culminates in a set of suggested core competencies for NPP managers which are further expanded in Appendix A. The annexes included provide specific examples of competency-based management selection, development, and assessment programmes in several Member States. -Annex A is one method to organize and display competencies. -Annex B is an example of using competencies for selection of first line managers. -Annex C is an example of using management competencies for succession management. -Annexes -H are examples of management development programmes. -Annexes I and J are examples of management assessment programmes. A glossary of terms is provided at the end of the report to explain the use of some key terms explain the use of some key terms

  16. Radioactive waste management for German nuclear power plants

    International Nuclear Information System (INIS)

    Weh, R.; Methling, D.; Sappok, M.

    1996-01-01

    In Germany, back-end fuel cycle provisions must be made for the twenty nuclear power plants currently run by utilities with an aggregate installed power of 23.4 GWe, and the four nuclear power plants already shut down. In addition, there are the shut down nuclear power plants of the former German Democratic Republic, and a variety of decommissioned prototype nuclear power plants built with the participation of the federal government and by firms other than utilities. The nuclear power plants operated by utilities contribute roughly one third of the total electricity generation in public power plants, thus greatly ensuring a stable energy supply in Germany. The public debate in Germany, however, focuses less on the good economic performance of these plants, and the positive acceptance at their respective sites, but rather on their spent fuel and waste management which, allegedly, is not safe enough. The spent fuel and waste management of German nuclear power plants is planned on a long-term basis, and executed in a responsible way by proven technical means, in the light of the provisions of the Atomic Act. Each of the necessary steps of the back end of the fuel cycle is planned and licensed in accordance with German nuclear law provisions. The respective facilities are built, commissioned, and monitored in operation with the dedicated assistance of expert consultants and licensing authorities. Stable boundary conditions are a prerequisite in ensuring the necessary stability in planning and running waste management schemes. As producers of waste, nuclear power plants are responsible for safe waste management and remain the owners of that waste until it has been accepted by a federal repository. (orig./DG) [de

  17. Conceptual definition of Automated Power Systems Management. [for planetary spacecraft

    Science.gov (United States)

    Imamura, M. S.; Skelly, L.; Weiner, H.

    1977-01-01

    Automated Power Systems Management (APSM) is defined as the capability of a spacecraft power system to automatically perform monitoring, computational, command, and control functions without ground intervention. Power systems for future planetary spacecraft must have this capability because they must perform up to 10 years, and accommodate real-time changes in mission execution autonomously. Specific APSM functions include fault detection, isolation, and correction; system performance and load profile prediction; power system optimization; system checkout; and data storage and transmission control. This paper describes the basic method of implementing these specific functions. The APSM hardware includes a central power system computer and a processor dedicated to each major power system subassembly along with digital interface circuitry. The major payoffs anticipated are in enhancement of spacecraft reliability and life and reduction of overall spacecraft program cost.

  18. A new islanding detection technique for multiple mini hydro based on rate of change of reactive power and load connecting strategy

    International Nuclear Information System (INIS)

    Laghari, J.A.; Mokhlis, H.; Bakar, A.H.A.; Karimi, M.

    2013-01-01

    Highlights: • The requirement of DG interconnection with existing power system is discussed. • Various islanding detection techniques are discussed with their merits and demerits. • New islanding detection strategy is proposed for multiple mini hydro type DGs. • The proposed strategy is based on dq/dt and load connecting strategy. • The effectiveness of strategy is verified on various other cases. - Abstract: The interconnection of distributed generation (DG) into distribution networks is undergoing a rapid global expansion. It enhances the system’s reliability, while simultaneously reduces pollution problems related to the generation of electrical power. To fully utilize the benefits of DGs, certain technical issues need to be addressed. One of the most important issues in this context is islanding detection. This paper presents a new islanding detection technique that is suitable for multiple mini-hydro type DG units. The proposed strategy is based on the rate of change of reactive power and load connecting strategy to detect islanding within the system. For a large power mismatch, islanding is detected by rate of change of reactive power only. However, for a close power mismatch, the rate of change of reactive power initiates a load connecting strategy, which in turn alters the load on the distribution network. This load variation in the distribution network causes a variation in the rate of change of reactive power, which is utilized to distinguish islanding and other events. The simulation results show that the proposed strategy is effective in detecting islanding occurrence in a distribution network

  19. Measurement of the CNA I's (Atucha I nuclear power plant) control rods reactivity during its commissioning on January 8th, 1990

    International Nuclear Information System (INIS)

    Waldman, R.M.; Gomez, A.

    1990-01-01

    Measurements were made on integral and differential calibration of rod 16, fuel racks RG and R3 and extinction reactivity during Atucha I nuclear power plant's commissioning on January 8th., 1990. These were the first physical measurements performed after the first critical nuclear power plant's commissioning. (Author) [es

  20. Life management plants at nuclear power plants PWR

    International Nuclear Information System (INIS)

    Esteban, G.

    2014-01-01

    Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

  1. A novel islanding detection scheme for synchronous distributed generation using rate of change of exciter voltage over reactive power at DG-Side

    DEFF Research Database (Denmark)

    Rostami, Ali; Bagheri, Marzieh; Naderi, Seyed Behzad

    2017-01-01

    , the reactive power at DG-side and exciter voltage parameters are selected. The performance of the proposed method is investigated in MATLAB/Simulink software on a sample network in the presence of synchronous diesel-generator. The simulation results indicate that the proposed method is capable to detect all......Penetration of distributed generation (DG) in distribution networks is rapidly increasing. DGs' application enhances system's reliability and power quality. However, along their benefits, there are some issues. One of the most important issues of DGs' application is the islanding. This paper...... of the synchronous generator. Therefore, due to lack of inertia, response of these parameters to small changes is faster than the other passive parameters such as frequency. However, the sensitivity of reactive power at the DG-side and the exciter voltage is much more than reactive power and voltage of the load. So...

  2. Integrated construction management technology for power plants

    International Nuclear Information System (INIS)

    Okada, Hisako; Miura, Jun; Nishitani, Yasuhiko

    2003-01-01

    The improvement and rationalization of the plant construction technology has been promoted in order to shorten the construction period, to improve the quality and reliability, and especially to reduce construction costs. With the recent remarkable advances of computer technology, it is necessary to introduce an electronic information technology (IT) into the construction field, and to develop a business process. In such a situation, Hitachi has developed and applied integrated construction support system, which is consistent among design, production and construction. This system has design information and schedule information made electronically as a basic database, and characterizes with project management function based on that information. By introduction of this system, electronic processing of information and reduction of paperwork has enabled high efficiency and standardization of on-site indirect work. Furthermore, by collaboration with the civil company, electrical data exchange has been carried out and developed techniques to improve the interface between mechanical and civil work. High accuracy of construction planning and unification of schedule data have been achieved, and consequently, rework and adjustment at the job site have been greatly reduced. (author)

  3. Buried piping integrity management at fossil power plants

    Energy Technology Data Exchange (ETDEWEB)

    Shulder, Stephen J. [Structural Integrity Associates, Annapolis, MD (United States); Biagiotti, Steve [Structural Integrity Associates, Inc., Centennial, CO (United States)

    2011-07-15

    In the last decade several industries (oil and gas pipelines, nuclear power, and municipal water) have experienced an increase in the frequency and public scrutiny of leaks and failures associated with buried piping and tank assets. In several industries, regulatory pressure has resulted in the mandated need for databases and inspection programs to document and ensure the continued integrity of these assets. Power plants are being extended beyond their design life and the condition of below grade assets is essential toward continued operation. This article shares the latest advances in managing design, operation, process, inspection, and historical data for power plant piping. Applications have also been developed to help with risk prioritization, inspection method selection, managing cathodic protection data for external corrosion control, and a wide variety of other information. This data can be managed in a GIS environment allowing two and three dimensional (2D and 3D) access to the database information. (orig.)

  4. Power plant operation and management in a deregulated market

    Energy Technology Data Exchange (ETDEWEB)

    Carraretto, Cristian [Department of Mechanical Engineering, University of Padova, Via Venezia, 1-35131 Padova (Italy)

    2006-05-15

    This paper analyzes the influence of electricity deregulation on the design, operation and management of the power plants owned by strategic and non-strategic producers. After a sensitivity analysis aimed at finding market conditions of profitable operation for thermal and hydroelectric power plants, a Nash-equilibrium market model is used to determine producers' optimum strategies, depending on their relative market power and overall production characteristics. Attention is then focused on the operation of single thermal power plants. Their short-term management plans and consequent effects on emission levels and residual life are described. The available reserve for primary and secondary control deriving from producers' market strategies is discussed. Some design options to improve combined cycles contribution to reserve service are finally described. The paper discusses these problems with a general approach, and uses many cases and examples derived from the current Italian scenario. (author)

  5. Power plant operation and management in a deregulated market

    International Nuclear Information System (INIS)

    Carraretto, Cristian

    2006-01-01

    This paper analyzes the influence of electricity deregulation on the design, operation and management of the power plants owned by strategic and non-strategic producers. After a sensitivity analysis aimed at finding market conditions of profitable operation for thermal and hydroelectric power plants, a Nash-equilibrium market model is used to determine producers' optimum strategies, depending on their relative market power and overall production characteristics. Attention is then focused on the operation of single thermal power plants. Their short-term management plans and consequent effects on emission levels and residual life are described. The available reserve for primary and secondary control deriving from producers' market strategies is discussed. Some design options to improve combined cycles contribution to reserve service are finally described. The paper discusses these problems with a general approach, and uses many cases and examples derived from the current Italian scenario. (author)

  6. Autonomous power management for interlinked AC-DC microgrids

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Meegahapola, Lasantha; Andrew, Loh Poh Chiang

    2018-01-01

    of the DC micro-grid before importing power from the interlinked AC microgrid. This strategy enables voltage regulation in the DC microgrid, and also reduces the number of converters in operation. The proposed scheme is fully autonomous while it retains the plug-n-play features for generators and tie......The existing power management schemes for inter-linked AC-DC microgrids have several operational drawbacks. Some of the existing control schemes are designed with the main objective of sharing power among the interlinked microgrids based on their loading conditions, while other schemes regulate...... the voltage of the interlinked microgrids without considering the specific loading conditions. However, the existing schemes cannot achieve both objectives efficiently. To address these issues, an autonomous power management scheme is proposed, which explicitly considers the specific loading condition...

  7. Calculation methods of reactivity using derivatives of nuclear power and Filter fir; Metodos para o calculo da reatividade usando derivadas da potencia nuclear e o filtro FIR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Daniel Suescun

    2007-07-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  8. Development of nuclear power plant management system for Kyushu Electric Power Co., Inc

    International Nuclear Information System (INIS)

    Nakamura, Kenichi; Akiyoshi, Tatsuo; Tanimoto, Kazuo; Ogura, Kazuhito; Ibi, Yuji; Kawasaki, Michiyuki

    2002-01-01

    The Kyushu Electric Power Co., Ltd. progresses development of the nuclear power plant management system using IT under aims at upgrading of efficiency, level, and reliability on maintenance and administration business under five years planning since 1999 fiscal year. The outline of the system are explained in this paper. As a result of preparation on power station net work and personal computers set in all of company, an environment capable of using these infrastructures and introducing large scale systems on transverse business over every groups of each power station could be established. (G.K.)

  9. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    Science.gov (United States)

    Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  10. Fundamentals of asset management in an ageing nuclear power station

    International Nuclear Information System (INIS)

    Crook, B.

    2014-01-01

    In an ageing nuclear power station there are many challenges associated with implementing and refining an asset management program. Ageing nuclear power stations are faced with the formidable task of replacing and refurbishing major Structures, Systems, and Components (SSCs) in a managed and cost-effective way. This paper provides a brief background on equipment reliability and asset management, covers Bruce Power's methodology for implementing this complex and all-encompassing program, and describes one of the key challenges faced by Bruce Power and the industry. The effective scoping and identification of critical components is an on-going challenge which can affect the integrity of many processes built upon it. This is a fundamental building block to nearly all processes at Bruce Power and one that is at the centre of many improvement initiatives and projects. The consequences from lacking this baseline data, or worse relying upon incorrect data, can permeate the asset management process and hinder the organization's ability to assess risk properly and take the necessary steps to mitigate this risk in the short and long term. (author)

  11. Environmental management systems implemented in the Spanish nuclear power plants

    International Nuclear Information System (INIS)

    Redondo, R.; Fernandez Guisado, M. B.; Hortiguela, R.; Bustamante, L. F.; Esparza, J. L.; Villareal, M.; Yague, F.

    2013-01-01

    The companies that own the Spanish Nuclear Power Plants, aware of social concern and in the context of a growing demanding environmental legislation, have a permanent commitment to the electricity production based on the principles of a maximum respect for the environment, safety, quality, professionalism and continuous improvement. In order to minimize the environmental impact of their plants they have implemented and Environmental Management System based on the ISO 14001 Standard. They minimize the environmental impact by identifying the significant environmental aspects and defining the corresponding objectives. This article describes the referred environmental management systems and their environmental objectives, as applied and defined by the Spanish Nuclear Power Plants. (Author)

  12. EDP systems for the operational management of nuclear power plant

    International Nuclear Information System (INIS)

    Doerler, R.

    1987-01-01

    An EDP-aided operational management system is to be understood as the total of all organizational conditions (structural organization, procedural organization) and technical means, and is intended to give the individual person a better overview to fulfill his/her responsibilities. The introduction of such a system is aimed at providing the operating personnel with a set of tools matching today's technology for management and administration systems which will enable them to fulfill their tasks in an optimum way. Powerful EDP systems are already used in many nuclear power plants to control and monitor operating processes and to collect and evaluate operational data. (orig./DG) [de

  13. Daya Bay Nuclear Power Station equipment reliability management system innovation

    International Nuclear Information System (INIS)

    Gao Ligang; Wang Zongjun

    2006-01-01

    Daya Bay Nuclear Power Station has achieved good performance since its commercial operation in 1994. The equipment reliability management system that features Daya Bay characteristics has been established through constant technology introduction, digestion and innovation. It is also based on the success of operational system, equipment maintenance system and technical support system. The system lays a solid foundation for the long-term safe operation of power station. This article emphasizes on the innovation part of equipment reliability management system in Daya Bay. (authors)

  14. An integrated reliability management system for nuclear power plants

    International Nuclear Information System (INIS)

    Kimura, T.; Shimokawa, H.; Matsushima, H.

    1998-01-01

    The responsibility in the nuclear field of the Government, utilities and manufactures has increased in the past years due to the need of stable operation and great reliability of nuclear power plants. The need to improve the reliability is not only for the new plants but also for those now running. So, several measures have been taken to improve reliability. In particular, the plant manufactures have developed a reliability management system for each phase (planning, construction, maintenance and operation) and these have been integrated as a unified system. This integrated reliability management system for nuclear power plants contains information about plant performance, failures and incidents which have occurred in the plants. (author)

  15. Dynamic Power Tariff for Congestion Management in Distribution Networks

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Shahidehpour, Mohammad

    2018-01-01

    This paper proposes dynamic power tariff (DPT), a new concept for congestion management in distribution networks with high penetration of electric vehicles (EVs), and heat pumps (HPs). The DPT concept is proposed to overcome a drawback of the dynamic tariff (DT) method, i.e., DPT can replace...... the price sensitivity parameter in the DT method, which is relatively unrealistic in practice. Based on the control theory, a control model with two control loops, i.e., the power flow control and voltage control, is established to analyze the congestion management process by the DPT method. Furthermore...

  16. Nuclear Power and Societal Problems in Risk Management

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1999-01-01

    Presently, nuclear power is in focus of the public safety concern and several governments are forced to reconsider its continued role in the national power policy. In this situation it is mandatory for the utilities and the industry to present credible risk management strategies. Development...... in this, some basic problems in the present models of accident causation are described with their influence on risk management strategies. Some critical research problems are identified and illustrated by examples of accidents within shipping, aviation, etc.and parallels drawn to the conditions of nuclear...

  17. Information Technology for Nuclear Power Plant Configuration Management

    International Nuclear Information System (INIS)

    2010-07-01

    Configuration management (CM) is an essential component of nuclear power plant design, construction and operation. The application of information technology (IT) offers a method to automate and ensure the timely and effective capture, processing and distribution of key nuclear power plant information to support CM principles and practical processes and procedures for implementation of CM at nuclear power plants. This publication reviews some of the principles established in IAEA-TECDOC-1335, 'Configuration Management in Nuclear Power Plants.' It also recaps tenets laid out in IAEA- TECDOC-1284, 'Information Technology Impact on Nuclear Power Plant Documentation' that supports CM programmes. This publication has been developed in conjunction with and designed to support these other two publications. These three publications combined provide a comprehensive discussion on configuration management, information technology and the relationship between them. An extensive discussion is also provided in this publication on the role of the design basis of the facility and its control through the CM process throughout the facility's lifetime. While this report was developed specifically for nuclear power plants, the principles discussed can be usefully applied to any high hazard nuclear facility

  18. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop and investig......Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop...... and investigate the use of a STATCOM by modelling and field testing an 8 MVar unit in a 24 MW wind farm....

  19. Reactive power and voltage control based on general quantum genetic algorithms

    DEFF Research Database (Denmark)

    Vlachogiannis, Ioannis (John); Østergaard, Jacob

    2009-01-01

    This paper presents an improved evolutionary algorithm based on quantum computing for optima l steady-state performance of power systems. However, the proposed general quantum genetic algorithm (GQ-GA) can be applied in various combinatorial optimization problems. In this study the GQ-GA determines...... techniques such as enhanced GA, multi-objective evolutionary algorithm and particle swarm optimization algorithms, as well as the classical primal-dual interior-point optimal power flow algorithm. The comparison demonstrates the ability of the GQ-GA in reaching more optimal solutions....

  20. Simulation of demand-response power management in smart city

    Science.gov (United States)

    Kadam, Kshitija

    Smart Grids manage energy efficiently through intelligent monitoring and control of all the components connected to the electrical grid. Advanced digital technology, combined with sensors and power electronics, can greatly improve transmission line efficiency. This thesis proposed a model of a deregulated grid which supplied power to diverse set of consumers and allowed them to participate in decision making process through two-way communication. The deregulated market encourages competition at the generation and distribution levels through communication with the central system operator. A software platform was developed and executed to manage the communication, as well for energy management of the overall system. It also demonstrated self-healing property of the system in case a fault occurs, resulting in an outage. The system not only recovered from the fault but managed to do so in a short time with no/minimum human involvement.