WorldWideScience

Sample records for based power system

  1. Power Line Communication Based Home Security System

    Directory of Open Access Journals (Sweden)

    Sankalp N. Gujar

    2013-11-01

    Full Text Available The aim of this paper is to demonstrate the use of Power line (A.C mains based security system i.e. developing the hardware for a microcontroller module that is to be interfaced to sensors which will detect breaches in security and developing a power line communication modem for sending/receiving data from the microcontroller modules over the power line. As soon as any one of the sensors in an establishment is triggered, the microcontroller will send data to the power line communication modem over UART. The modem will then convert the incoming data into a packet, modulate it using ASK and transmit it over the power line through the coupling circuit. The modem at the security cabin will demodulate this packet and send it to the microcontroller over UART. The microcontroller then activates the alarm and displays the location and nature of the breach on the display

  2. Systems definition space based power conversion systems: Executive summary

    Science.gov (United States)

    1977-01-01

    Potential space-located systems for the generation of electrical power for use on earth were investigated. These systems were of three basic types: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  3. Response Based Emergency Control System for Power System Transient Stability

    OpenAIRE

    Huaiyuan Wang; Baohui Zhang; Zhiguo Hao

    2015-01-01

    A transient stability control system for the electric power system composed of a prediction method and a control method is proposed based on trajectory information. This system, which is independent of system parameters and models, can detect the transient stability of the electric power system quickly and provide the control law when the system is unstable. Firstly, system instability is detected by the characteristic concave or convex shape of the trajectory. Secondly, the control method is...

  4. Fuzzy Logic Based Power System Contingency Ranking

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-02-01

    Full Text Available Voltage stability is a major concern in planning and operations of power systems. It is well known that voltage instability and collapse have led to major system failures. Modern transmission networks are more heavily loaded than ever before to meet the growing demand. One of the major consequences resulted from such a stressed system is voltage collapse or instability. This paper presents maximum loadability identification of a load bus in a power transmission network. In this study, Fast Voltage Stability Index (FVSI is utilized as the indicator of the maximum loadability termed as Qmax. In this technique, reactive power loading will be increased gradually at particular load bus until the FVSI reaches close to unity. Therefore, a critical value of FVSI was set as the maximum loadability point. This value ensures the system from entering voltage-collapse region. The main purpose in the maximum loadability assessment is to plan for the maximum allowable load value to avoid voltage collapse; which is important in power system planning risk assessment.The most important task in security analysis is the problem of identifying the critical contingencies from a large list of credible contingencies and ranks them according to their severity. The condition of voltage stability in a power system can be characterized by the use of voltage stability indices. This paper presents fuzzy approach for ranking the contingencies using composite-index based on parallel operated fuzzy inference engine. The Line Flow index (L.F and bus Voltage Magnitude (VM of the load buses are expressed in fuzzy set notation. Further, they are evaluated using Fuzzy rules to obtain overall Criticality Index. Contingencies are ranked based on decreasing order of Criticality Index and then provides the comparison of ranking obtained with FVSI method.

  5. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  6. Response Based Emergency Control System for Power System Transient Stability

    Directory of Open Access Journals (Sweden)

    Huaiyuan Wang

    2015-11-01

    Full Text Available A transient stability control system for the electric power system composed of a prediction method and a control method is proposed based on trajectory information. This system, which is independent of system parameters and models, can detect the transient stability of the electric power system quickly and provide the control law when the system is unstable. Firstly, system instability is detected by the characteristic concave or convex shape of the trajectory. Secondly, the control method is proposed based on the analysis of the slope of the state plane trajectory when the power system is unstable. Two control objectives are provided according to the methods of acquiring the far end point: one is the minimal cost to restore the system to a stable state; the other one is the minimal cost to limit the maximum swing angle. The simulation indicates that the mentioned transient stability control system is efficient.

  7. Design considerations for lunar base photovoltaic power systems

    Science.gov (United States)

    Hickman, J. Mark; Curtis, Henry B.; Landis, Geoffrey A.

    1990-01-01

    A survey was made of factors that may affect the design of photovoltaic arrays for a lunar base. These factors, which include the lunar environment and system design criteria, are examined. A photovoltaic power system design with a triangular array geometry is discussed and compared to a nuclear reactor power systems and a power system utilizing both nuclear and solar power sources.

  8. 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.

  9. Power-based control of physical systems

    OpenAIRE

    Garcia-Canseco, Eloisa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M. A.

    2010-01-01

    It is well known that energy-balancing control is stymied by the presence of pervasive dissipation. To overcome this problem in electrical circuits, the alternative paradigm of power shaping was introduced in Ortega, Jeltsema, and Scherpen (2003)-where, as suggested by its name, stabilization is achieved shaping a function akin to the power instead of the energy function. In this paper we extend this technique to general nonlinear systems. The method relies on the solution of a PDE, which ide...

  10. Market Based Analysis of Power System Interconnections

    OpenAIRE

    Obuševs, A; Turcik, M; Oļeiņikova, I; Junghāns, G

    2011-01-01

    Analysis in this Article is focused on usage of transmission grid under liberalized market with implicit transmission capacity allocation method, e.g. Nordic market. Attention is paid on fundamental changes in transmission utilization and its economical effective operation. For interconnection and power flow analysis and losses calculation model of Nordic grid was developed and transmission losses calculation method was created. Given approach will improve economical efficiency of system oper...

  11. Systems definition space-based power conversion systems. [for satellite power transmission to earth

    Science.gov (United States)

    1976-01-01

    Potential space-located systems for the generation of electrical power for use on Earth are discussed and include: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; and (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Systems (1) and (2) would utilize a microwave beam system to transmit their output to Earth. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  12. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O.P.; Chen, G.P.; Zhang, Y.; El-Metwally, K. [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  13. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network w...... power system can be easily predicted through Nyquist diagrams. Time-domain simulations and experimental tests on a three-inverter-based power system are presented. The results validate the effectiveness of the theoretical approach....

  14. A cooperative power trading system based on satisfaction space technology

    International Nuclear Information System (INIS)

    This paper proposed a new power trading system model designed to ensure customer cooperation with power suppliers. Designed as an Internet application, the cooperative power trading system modelled power markets using a satisfaction space technology A network model of electric power trading systems was developed to create a communication network system that consisted of suppliers, customers, and auctioneers. When demand exceeded supply, the auctioneer in the trading system requested power reductions from customers. Rewards were paid to maintain the degree of satisfaction of the customers. The supplier's evaluation function was defined as a function of market price and power supply. A power reducing method was developed using a combinatorial optimization technique. Suppliers and customers submitted bids for initial power trading quantities, while the auctioneer decided a market price based on bidding values. After receiving the market price, suppliers and customers submitted a second set of bids for expected power trading quantities. A power reduction plan was then developed by the auctioneer to balance the amount of power supply and demand. The system can be applied to customers whose evaluation functions cannot be estimated beforehand, as the auctioneer was able to choose the most efficient power reduction point selected by consumers using a maximum steep slope method. Simulations conducted to validate the trading system demonstrated that the system is capable of choosing efficient energy reduction plans. 6 refs., 4 tabs., 3 figs

  15. Probabilistic Model-Based Diagnosis for Electrical Power Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — We present in this article a case study of the probabilistic approach to model-based diagnosis. Here, the diagnosed system is a real-world electrical power system,...

  16. Power System Stabilizer Based on Global Fuzzy Sliding Mode Control

    OpenAIRE

    Nechadi, E.; Harmas, M. N.

    2013-01-01

    Power systems stability is enhanced through a novel stabiliser developed around a fuzzy sliding mode approach. First, sliding mode control is applied to selected operating point based models of a power system separately then fuzzy logic is used to form a global model encompassing the separate subsystems, thus leading to a fuzzy sliding mode power system control. Stability is insured through Lyapunov synthesis. Severe operating conditions are used in a simulation study to test the validity of...

  17. Rural Power System Load Forecast Based on Principal Component Analysis

    Institute of Scientific and Technical Information of China (English)

    Fang Jun-long; Xing Yu; Fu Yu; Xu Yang; Liu Guo-liang

    2015-01-01

    Power load forecasting accuracy related to the development of the power system. There were so many factors influencing the power load, but their effects were not the same and what factors played a leading role could not be determined empirically. Based on the analysis of the principal component, the paper forecasted the demands of power load with the method of the multivariate linear regression model prediction. Took the rural power grid load for example, the paper analyzed the impacts of different factors on power load, selected the forecast methods which were appropriate for using in this area, forecasted its 2014-2018 electricity load, and provided a reliable basis for grid planning.

  18. Knowledge based system for fouling assessment of power plant boiler

    International Nuclear Information System (INIS)

    The paper presents the design of an expert system for fouling assessment in power plant boilers. It is an on-line expert system based on selected criteria for the fouling assessment. Using criteria for fouling assessment based on 'clean' and 'not-clean' radiation heat flux measurements, the diagnostic variable are defined for the boiler heat transfer surface. The development of the prototype knowledge-based system for fouling assessment in power plants boiler comprise the integrations of the elements including knowledge base, inference procedure and prototype configuration. Demonstration of the prototype knowledge-based system for fouling assessment was performed on the Sines power plant. It is a 300 MW coal fired power plant. 12 fields are used with 3 on each side of boiler

  19. High power microwave system based on power combining and pulse compression of conventional klystrons

    OpenAIRE

    Xiong, Zheng-Feng; Chen, Huai-Bi; Cheng, Cheng; Ning, Hui; Tang, Chuan-Xiang

    2015-01-01

    A high power microwave system based on power combining and pulse compression of conventional klystrons is introduced in this paper. This system mainly consists of pulse modulator, power combiner, driving source of klystrons and pulse compressor. A solid state induction modulator and pulse transformer were used to drive two 50 MW S-band klystrons with pulse widths 4 {\\mu}s in parallel, after power combining and pulse compression, the tested peak power had reached about 210 MW with pulse widths...

  20. SEE SAW BASED REGENERATIVE POWER SYSTEM

    OpenAIRE

    Tribhuwan Singh; Shahzad Ali

    2016-01-01

    Research related to electrical vehicles is gaining importance due to the energy crisis. Using regenerative braking when braking, improves the efficiency of an electric vehicle as it recovers energy that could go to waste if mechanical brakes were used. A novel regenerative braking system for neighborhood electric vehicles was designed, prototyped and tested. The proposed system utilizes a seesaw system to capture energy whereas the conventional systems regenerate to the batteries. The user ha...

  1. A Series-LC-Filtered Active Damper for AC Power Electronics Based Power Systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang;

    2015-01-01

    This paper proposes an active damper with a series LC-filter for suppressing resonances in an ac power electronics based power system. The added filter capacitor helps to lower the voltage stress of the converter to be used for implementing the damper. Unlike active filters for the compensation...... is built, where the damper is integrated into a grid-connected converter. The results obtained from the experiments demonstrate the stability enhancement of ac power electronics based power systems by the active damper....

  2. Wide Area Measurement Based Security Assessment & Monitoring of Modern Power System: A Danish Power System Case Study

    DEFF Research Database (Denmark)

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

    2013-01-01

    monitoring of modern power system with large scale renewable energy penetration. Phasor measurement unit (PMU) based WAMS has been implemented in western Danish Power System to realize online security monitoring and assessment in power system control center. The proposed security monitoring system has been......Power System security has become a major concern across the global power system community. This paper presents wide area measurement system (WAMS) based security assessment and monitoring of modern power system. A new three dimensional security index (TDSI) has been proposed for online security...

  3. Photovoltaic power system considerations for future lunar bases

    Science.gov (United States)

    Flood, Dennis J.; Appelbaum, Joseph

    1989-01-01

    The cost of transportation to the lunar surface places a premium on developing ultralightweight power system technology to support the eventual establishment of a lunar base. The photovoltaic technology issues to be addressed by the Surface Power program element of NASA's Project Pathfinder are described.

  4. Power allocation strategies for distributed precoded multicell based systems

    Directory of Open Access Journals (Sweden)

    Silva Adão

    2011-01-01

    Full Text Available Abstract Multicell cooperation is a promising solution for cellular wireless systems to mitigate intercell interference, improve system fairness, and increase capacity. In this article, we propose power allocation techniques for the downlink of distributed, precoded, multicell cellular-based systems. The precoder is designed in two phases: first the intercell interference is removed by applying a set of distributed precoding vectors; then the system is further optimized through power allocation. Three centralized power allocation algorithms with per-BS power constraint and different complexity trade-offs are proposed: one optimal in terms of minimization of the instantaneous average bit error rate (BER, and two suboptimal. In this latter approach, the powers are computed in two phases. First, the powers are derived under total power constraint (TPC and two criterions are considered, namely, minimization of the instantaneous average BER and minimization of the sum of inverse of signal-to-noise ratio. Then, the final powers are computed to satisfy the individual per-BS power constraint. The performance of the proposed schemes is evaluated, considering typical pedestrian scenarios based on LTE specifications. The numerical results show that the proposed suboptimal schemes achieve a performance very close to the optimal but with lower computational complexity. Moreover, the performance of the proposed per-BS precoding schemes is close to the one obtained considering TPC over a supercell.

  5. Advanced photovoltaic power system technology for lunar base applications

    Science.gov (United States)

    Brinker, David J.; Flood, Dennis J.

    1992-01-01

    The development of an advanced photovoltaic power system that would have application for a manned lunar base is currently planned under the Surface Power element of Pathfinder. Significant mass savings over state-of-the-art photovoltaic/battery systems are possible with the use of advanced lightweight solar arrays coupled with regenerative fuel cell storage. The solar blanket, using either ultrathin GaAs or amorphous silicon solar cells, would be integrated with a reduced-g structure. Regenerative fuel cells with high-pressure gas storage in filament-wound tanks are planned for energy storage. An advanced PV/RFC power system is a leading candidate for a manned lunar base as it offers a tremendous weight advantage over state-of-the-art photovoltaic/battery systems and is comparable in mass to other advanced power generation technologies.

  6. High power microwave system based on power combining and pulse compression of conventional klystrons

    CERN Document Server

    Xiong, Zheng-Feng; Cheng, Cheng; Ning, Hui; Tang, Chuan-Xiang

    2015-01-01

    A high power microwave system based on power combining and pulse compression of conventional klystrons is introduced in this paper. This system mainly consists of pulse modulator, power combiner, driving source of klystrons and pulse compressor. A solid state induction modulator and pulse transformer were used to drive two 50 MW S-band klystrons with pulse widths 4 {\\mu}s in parallel, after power combining and pulse compression, the tested peak power had reached about 210 MW with pulse widths nearly 400 ns at 25 Hz, while the experimental maximum output power was just limited by the power capacity of loads. This type of high power microwave system has widely application prospect in RF system of large scale particle accelerators, high power radar transmitters and high level electromagnetic environment generators.

  7. Power system distributed oscilation detection based on Synchrophasor data

    Science.gov (United States)

    Ning, Jiawei

    Along with increasing demand for electricity, integration of renewable energy and deregulation of power market, power industry is facing unprecedented challenges nowadays. Within the last couple of decades, several serious blackouts have been taking place in United States. As an effective approach to prevent that, power system small signal stability monitoring has been drawing more interests and attentions from researchers. With wide-spread implementation of Synchrophasors around the world in the last decade, power systems real-time online monitoring becomes much more feasible. Comparing with planning study analysis, real-time online monitoring would benefit control room operators immediately and directly. Among all online monitoring methods, Oscillation Modal Analysis (OMA), a modal identification method based on routine measurement data where the input is unmeasured ambient excitation, is a great tool to evaluate and monitor power system small signal stability. Indeed, high sampling Synchrophasor data around power system is fitted perfectly as inputs to OMA. Existing methods in OMA for power systems are all based on centralized algorithms applying at control centers only; however, with rapid growing number of online Synchrophasors the computation burden at control centers is and will be continually exponentially expanded. The increasing computation time at control center compromises the real-time feature of online monitoring. The communication efforts between substation and control center will also be out of reach. Meanwhile, it is difficult or even impossible for centralized algorithms to detect some poorly damped local modes. In order to avert previous shortcomings of centralized OMA methods and embrace the new changes in the power systems, two new distributed oscillation detection methods with two new decentralized structures are presented in this dissertation. Since the new schemes brought substations into the big oscillation detection picture, the proposed

  8. Site selection of active damper for stabilizing power electronics based power distribution system

    DEFF Research Database (Denmark)

    Yoon, Changwoo; Wang, Xiongfei; Bak, Claus Leth;

    2015-01-01

    Stability in the nowadays distribution power system is endangered by interaction problems that may arise from newly added power-electronics based power devices. Recently, a new concept to deal with this higher frequency instability, the active damper, has been proposed. The active damper is a pow...

  9. AC Power Routing System in Home Based on Demand and Supply Utilizing Distributed Power Sources

    Directory of Open Access Journals (Sweden)

    Takashi Hikihara

    2011-04-01

    Full Text Available To help reduce consumption of fossil fuels, renewable, natural and distributed power sources are being adopted. These alternative energy sources inevitably show fluctuations in the amount of output power, frequency, and voltage. The suppression of such fluctuations is a key issue to avoid disturbances in power grids. A similar situation arises as far as the regulation of in-home power flow is concerned. We focus on the quality of supplied and demanded power in particular. In this paper, an in-home power distribution system based on information of power is proposed. The system is developed in order to integrate power dispatch and communication. The experimental results show the feasibility of new flexible and efficient power management approaches.

  10. Small reactor power systems for manned planetary surface bases

    International Nuclear Information System (INIS)

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options

  11. Management of a power system based on renewable energy

    Directory of Open Access Journals (Sweden)

    Ronay Karoly

    2012-06-01

    Full Text Available This article main purpose is to highlight the main advantage of the hardware and software implementation for an energy management system based on renewable energy sources. By using implemented and dedicated hardware and software the evolution of energy production and consumption can be monitored. The advantages of such system are highlighted by the results obtained from experimental simulations. An experimental model for the power system based on renewable energy sources was implemented, where the actual status of the system in different situations when the equipments change their own statuses can be shown.

  12. Spacecraft power system controller based on neural network

    Science.gov (United States)

    El-madany, Hanaa T.; Fahmy, Faten H.; El-Rahman, Ninet M. A.; Dorrah, Hassen T.

    2011-09-01

    Neural control is a branch of the general field of intelligent control, which is based on the concept of artificial intelligence. This work presents the spacecraft orbit determination, dimensioning of the renewable power system, and mathematical modeling of spacecraft power system which are required for simulating the system. The complete system is simulated using MATLAB-SIMULINK. The NN controller outperform PID in the extreme range of non-linearity. Well trained neural controller can operate at different conditions of load current at different orbital periods without any tuning such in case of PID controller. So an artificial neural network (ANN) based model has been developed for the optimum operation of spacecraft power system. An ANN is trained using a back propagation with Levenberg-Marquardt algorithm. The best validation performance is obtained for mean square error is equal to 9.9962×10 -11 at epoch 637. The regression between the network output and the corresponding target is equal to 100% which means a high accuracy. NNC architecture gives satisfactory results with small number of neurons, hence better in terms of memory and time are required for NNC implementation. The results indicate that the proposed control unit using ANN can be successfully used for controlling the spacecraft power system in low earth orbit (LEO). Therefore, this technique is going to be a very useful tool for the interested designers in space field.

  13. Price-based Optimal Control of Electrical Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jokic, A.

    2007-09-10

    The research presented in this thesis is motivated by the following issue of concern for the operation of future power systems: Future power systems will be characterized by significantly increased uncertainties at all time scales and, consequently, their behavior in time will be difficult to predict. In Chapter 2 we will present a novel explicit, dynamic, distributed feedback control scheme that utilizes nodal-prices for real-time optimal power balance and network congestion control. The term explicit means that the controller is not based on solving an optimization problem on-line. Instead, the nodal prices updates are based on simple, explicitly defined and easily comprehensible rules. We prove that the developed control scheme, which acts on the measurements from the current state of the system, always provide the correct nodal prices. In Chapter 3 we will develop a novel, robust, hybrid MPC control (model predictive controller) scheme for power balance control with hard constraints on line power flows and network frequency deviations. The developed MPC controller acts in parallel with the explicit controller from Chapter 2, and its task is to enforce the constraints during the transient periods following suddenly occurring power imbalances in the system. In Chapter 4 the concept of autonomous power networks will be presented as a concise formulation to deal with economic, technical and reliability issues in power systems with a large penetration of distributed generating units. With autonomous power networks as new market entities, we propose a novel operational structure of ancillary service markets. In Chapter 5 we will consider the problem of controlling a general linear time-invariant dynamical system to an economically optimal operating point, which is defined by a multiparametric constrained convex optimization problem related with the steady-state operation of the system. The parameters in the optimization problem are values of the exogenous inputs to

  14. Neural Network Predictive Control Based Power System Stabilizer

    Directory of Open Access Journals (Sweden)

    Ali Mohamed Yousef

    2012-04-01

    Full Text Available The present study investigates the power system stabilizer based on neural predictive control for improving power system dynamic performance over a wide range of operating conditions. In this study a design and application of the Neural Network Model Predictive Controller (NN-MPC on a simple power system composed of a synchronous generator connected to an infinite bus through a transmission line is proposed. The synchronous machine is represented in detail, taking into account the effect of the machine saliency and the damper winding. Neural network model predictive control combines reliable prediction of neural network model with excellent performance of model predictive control using nonlinear Levenberg-Marquardt optimization. This control system is used the rotor speed deviation as a feedback signal. Furthermore, the using performance system of the proposed controller is compared with the system performance using conventional one (PID controller through simulation studies. Digital simulation has been carried out in order to validate the effectiveness proposed NN-MPC power system stabilizer for achieving excellent performance. The results demonstrate that the effectiveness and superiority of the proposed controller in terms of fast response and small settling time.

  15. Repowering flexibility of coal-based advanced power systems

    Energy Technology Data Exchange (ETDEWEB)

    Bajura, R.A.; Bechtel, T.F.; Schmidt, D.K.; Wimer, J.G.

    1995-03-01

    The Department of Energy`s (DOE`s) Morgantown Energy Technology Center (METC) helps enhance the economic competitiveness, environmental quality, and national well-being of the U.S. by developing advanced power-generation systems. The potential market for advanced power-generation systems is large. In the U.S., electric demand is estimated to grow at about 1 percent per year through the year 2010. The total power generation market also includes new-capacity as well as replacement of existing power plants as they age. Thus, the market for power systems over the next 15 years is estimated to be about 279,000 megawatts (MW), but could range from as much as 484,000 MW to as little as 153,000 MW. These predictions are summarized. Over the next 15 years, the replacement market is potentially much larger than the expansion market because of the large base of aging power plants in the U.S.

  16. Agent Based Control of Electric Power Systems with Distributed Generation

    DEFF Research Database (Denmark)

    Saleem, Arshad

    Distributed generation, decentralized and local control, self organization and autonomy are evident trends of today's electric power systems focusing on innovative control architectures such as MicroGrids, Virtual Power Plants, Cell based systems, plug-in electric vehicles and real time markets...... and subsystems that are able to coordinate, communicate, cooperate, adapt to emerging situations and self organize in an intelligent way. At the same time, rapid development in information and and communication technologies (ICT) have brought new opportunities and elucidations. New Technologies and standards...... have been developed particularly in the area of communication and distributed control. Electric power industry is eager to explore, evaluate and adopt these new advancements in ICT for improving its current practices of automation and control in order to cope with above mentioned challenges...

  17. A microprocessor-based power control data acquisition system

    International Nuclear Information System (INIS)

    The project reported deals with one of the aspects of power plant control and management. In order to perform optimal distribution of power and load switching, one has to solve a specific optimization problem. In order to solve this problem one needs to collect current and power expenditure data from a large number of channels and have them processed. This particular procedure is defined as data acquisition and it constitutes the main topic of this project. A microprocessor-based data acquisition system for power management is investigated and developed. The current and power data of about 100 analog channels are sampled and collected in real-time. These data are subsequently processed to calculate the power factor (cos phi) for each channel and the maximum demand. The data is processed by an AMD 9511 Arithmetic Processing Unit and the whole system is controlled by an Intel 8080A CPU. All this information is then transfered to a universal computer through a synchronized communication channel. The optimization computations would be performed by the high level computer. Different ways of performing the search of data over a large number of channels have been investigated. A particular solution to overcome the gain and offset drift of the A/D converter, using software, has been proposed. The 8080A supervises the collection and routing of data in real time, while the 9511 performs calculation, using these data. (Author)

  18. Security region based real and reactive power pricing of power system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper develops a novel model and an algorithm of security region based real and reactive power pricing of power systems.In the proposed model,the reactive power production cost is represented as the opportunity cost.The static voltage stability region in the cut set power space(CVSR) and the practical dynamic security region(PDSR) in the injection power space are used to represent the constraints of voltage stability and transient stability,so that the consideration of this kind of constraints in the optimization becomes very easy.In the proposed algorithm,a decoupled optimization and iteration method of active power production cost and reactive power production cost is suggested.According to the K-T optimality conditions,the prices of active power and reactive power,and the different components corresponding to the concerned security constraints are derived.The components of spot prices can reflect the influence of different node power injections on each kind of security constraints,so that through the node price all of the participants in power market can be stimulated to take an active part in maintaining the system security.An illustrative example on the New England 10-genetator 39-bus System is used to demonstrate the proposed method.

  19. Security region based real and reactive power pricing of power system

    Institute of Scientific and Technical Information of China (English)

    YU YiXin; WANG YanJun

    2008-01-01

    This paper develops a novel model and an algorithm of security region based real and reactive power pricing of power systems. In the proposed model, the reactive power production cost is represented as the opportunity cost. The static voltage stability region in the cut set power space (CVSR) and the practical dynamic secu-rity region (PDSR) in the injection power space are used to represent the con-straints of voltage stability and transient stability, so that the consideration of this kind of constraints in the optimization becomes very easy. In the proposed algo-rithm, a decoupled optimization and iteration method of active power production cost and reactive power production cost is suggested. According to the K-T opti-mality conditions, the prices of active power and reactive power, and the different components corresponding to the concerned security constraints are derived. The components of spot prices can reflect the influence of different node power injec-tions on each kind of security constraints, so that through the node price all of the participants in power market can be stimulated to take an active part in maintaining the system security. An illustrative example on the New England 10-generator 39-bus System is used to demonstrate the proposed method.

  20. Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

    Science.gov (United States)

    Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

    2008-12-01

    Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

  1. Data warehouse based decision support system in nuclear power plants

    International Nuclear Information System (INIS)

    Safety is an important element in business decision making processes in nuclear power plants. Information about component reliability, structures and systems, data recorded during the nuclear power plant's operation and outage periods, as well as experiences from other power plants are located in different database systems throughout the power plant. It would be possible to create a decision support system which would collect data, transform it into a standardized form and store it in a single location in a format more suitable for analyses and knowledge discovery. This single location where the data would be stored would be a data warehouse. Such data warehouse based decision support system could help make decision making processes more efficient by providing more information about business processes and predicting possible consequences of different decisions. Two main functionalities in this decision support system would be an OLAP (On Line Analytical Processing) and a data mining system. An OLAP system would enable the users to perform fast, simple and efficient multidimensional analysis of existing data and identify trends. Data mining techniques and algorithms would help discover new, previously unknown information from the data as well as hidden dependencies between various parameters. Data mining would also enable analysts to create relevant prediction models that could predict behaviour of different systems during operation and inspection results during outages. The basic characteristics and theoretical foundations of such decision support system are described and the reasons for choosing a data warehouse as the underlying structure are explained. The article analyzes obvious business benefits of such system as well as potential uses of OLAP and data mining technologies. Possible implementation methodologies and problems that may arise, especially in the field of data integration, are discussed and analyzed.(author)

  2. A GIS-based Power Transmission Management Information System

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>Based on analyzing the shortcomings of electric power enterprise in traditional operation pattern,this paper combines components GIS with the application of management information system,and uses the structure which unifies three layers C/S and B/S.Also,proposed using the GPS intellectualization patrol.This may be useful to guarantees the transmission line’s operation to be safe and stable.

  3. Artificial Intelligence Based Optimal Configuration of Hybrid Power Generation System

    OpenAIRE

    Suryoatmojo, Heri; スルヨアトモジョ, ヘリ

    2010-01-01

    As discussed in this chapter, PV and wind energy are the most promising as a future energy technology and can be classified as a clean sources of electric energy in the world. Due to the unexpected power variation of these sources utilization of these sources with Diesel generator unit and battery system is a challenging aspect that must be overcome in this thesis. This dissertation presents a proposed package of computer programs based pm Matlab software. This package presents a complete des...

  4. JMF-based video monitoring system for power station equipment

    Science.gov (United States)

    Qin, Jinlei; Li, Zheng; Niu, Yuguang

    2012-01-01

    A remote video monitoring system based on Java Media Framework (JMF) is put forward in this paper. It is of cross-platform, lower time-delay and lower bandwidth. The system is consisted of three layers that are data acquisition layer, service layer and client layer. The hardware of system is connected with local area network and various video devices can be identified in the system. The software based on Java and JMF is programmed to capture, compress, send, receive and play video data and can be run on different operating system without modification. H.263 compression algorithm is adopted and RTP protocol is used to transport video data with RTCP protocol in the system. The client layer can access to the system by Internet or 3G and has convenient and flexible features. Maintenance personnel can easily supervise the device status at any time so that the equipments are always in good condition. It is helpful to enhance the competitive power of power plants.

  5. Modeling and analysis of harmonic resonance in a power electronics based AC power system

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe;

    2013-01-01

    -based analysis approach is adopted and expanded to a meshed and balanced three-phase power network. An impedance ratio derivation method is proposed based on the nodal admittance matrix. By this means, the contribution of each inverter to the system resonance modes can be easily predicted by the Nyquist...

  6. OPF-Based Optimal Location of Two Systems Two Terminal HVDC to Power System Optimal Operation

    Directory of Open Access Journals (Sweden)

    Mehdi Abolfazli

    2013-04-01

    Full Text Available In this paper a suitable mathematical model of the two terminal HVDC system is provided for optimal power flow (OPF and optimal location based on OPF such power injection model. The ability of voltage source converter (VSC-based HVDC to independently control active and reactive power is well represented by the model. The model is used to develop an OPF-based optimal location algorithm of two systems two terminal HVDC to minimize the total fuel cost and active power losses as objective function. The optimization framework is modeled as non-linear programming (NLP and solved by Matlab and GAMS softwares. The proposed algorithm is implemented on the IEEE 14- and 30-bus test systems. The simulation results show ability of two systems two terminal HVDC in improving the power system operation. Furthermore, two systems two terminal HVDC is compared by PST and OUPFC in the power system operation from economical and technical aspects.

  7. Bases of theory of economic systems' power. Total power of the economic systems. Intangible power of the economic systems. Innovative power of the economic systems

    OpenAIRE

    Oleksandr Morozov

    2014-01-01

    The basic principles, determinations of concepts of theory, denotations of parameters and their dimension are formulated, as well as the algorithm of calculation of indexes of total, intangible and innovative power of the economic systems of five levels.

  8. Reachability analysis based transient stability design in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Licheng; Kumar, Ratnesh; Elia, Nicola [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50010 (United States)

    2010-09-15

    This paper provides a systematic framework to determine switching control strategies to stabilize the system after a fault if the stabilization is possible. A method to compute the stability region of a stable equilibrium point with the purpose of power system stability analysis is proposed and the validity of discrete controls in transient stability design is studied. First, a Hamilton-Jacobi-Isaas (HJI) partial differential equation (PDE) is constructed to describe the set of backward reachable states as a function of time starting from a target set of states. The backward reachable set of a stable equilibrium point is computed by numerically solving the HJI PDE backwardly in time using level set methods. This backward reachable set yields the stability region of the equilibrium point. Based on such reachability analysis, a transient stability design method is presented. The validity of a discrete control is determined by examining the stability region of the power system with the said control on. If a post-fault initial state is in the stability region of the system with a control on, the control is valid. A control strategy is provided based on the validity of controls. Finally, this method is illustrated by applying to a single machine infinite bus system with the compensation of shunt and series capacitors. (author)

  9. Multiagent based protection and control in decentralized electric power systems

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Veloso, Manuela

    2010-01-01

    Electric power systems are going through a major change both in their physical and control structure. A large num- ber of small and geographically dispersed power generation units (e.g., wind turbines, solar cells, plug-in electric cars) are replacing big centralized power plants. This shift has...... created interesting possibilities for application of intelligent systems such as multiagent systems for control and automation in electric power systems. This paper describes work on designing a multiagent system for protection and control of electric power distribution networks.It demonstrates how...... explicit modeling of capabilities, states, roles and role transition in agents can capture the control and automation in electric power systems. We present illustrative results from using our proposed schema in realistic simulations....

  10. Enhanced GSA-Based Optimization for Minimization of Power Losses in Power System

    Directory of Open Access Journals (Sweden)

    Gonggui Chen

    2015-01-01

    Full Text Available Gravitational Search Algorithm (GSA is a heuristic method based on Newton’s law of gravitational attraction and law of motion. In this paper, to further improve the optimization performance of GSA, the memory characteristic of Particle Swarm Optimization (PSO is employed in GSAPSO for searching a better solution. Besides, to testify the prominent strength of GSAPSO, GSA, PSO, and GSAPSO are applied for the solution of optimal reactive power dispatch (ORPD of power system. Conventionally, ORPD is defined as a problem of minimizing the total active power transmission losses by setting control variables while satisfying numerous constraints. Therefore ORPD is a complicated mixed integer nonlinear optimization problem including many constraints. IEEE14-bus, IEEE30-bus, and IEEE57-bus test power systems are used to implement this study, respectively. The obtained results of simulation experiments using GSAPSO method, especially the power loss reduction rates, are compared to those yielded by the other modern artificial intelligence-based techniques including the conventional GSA and PSO methods. The results presented in this paper reveal the potential and effectiveness of the proposed method for solving ORPD problem of power system.

  11. Chance-Constrained System of Systems Based Operation of Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kargarian, Amin; Fu, Yong; Wu, Hongyu

    2016-09-01

    In this paper, a chance-constrained system of systems (SoS) based decision-making approach is presented for stochastic scheduling of power systems encompassing active distribution grids. Based on the concept of SoS, the independent system operator (ISO) and distribution companies (DISCOs) are modeled as self-governing systems. These systems collaborate with each other to run the entire power system in a secure and economic manner. Each self-governing system accounts for its local reserve requirements and line flow constraints with respect to the uncertainties of load and renewable energy resources. A set of chance constraints are formulated to model the interactions between the ISO and DISCOs. The proposed model is solved by using analytical target cascading (ATC) method, a distributed optimization algorithm in which only a limited amount of information is exchanged between collaborative ISO and DISCOs. In this paper, a 6-bus and a modified IEEE 118-bus power systems are studied to show the effectiveness of the proposed algorithm.

  12. An integrated analytic tool and knowledge-based system approach to aerospace electric power system control

    Science.gov (United States)

    Owens, William R.; Henderson, Eric; Gandikota, Kapal

    1986-10-01

    Future aerospace electric power systems require new control methods because of increasing power system complexity, demands for power system management, greater system size and heightened reliability requirements. To meet these requirements, a combination of electric power system analytic tools and knowledge-based systems is proposed. The continual improvement in microelectronic performance has made it possible to envision the application of sophisticated electric power system analysis tools to aerospace vehicles. These tools have been successfully used in the measurement and control of large terrestrial electric power systems. Among these tools is state estimation which has three main benefits. The estimator builds a reliable database for the system structure and states. Security assessment and contingency evaluation also require a state estimator. Finally, the estimator will, combined with modern control theory, improve power system control and stability. Bad data detection as an adjunct to state estimation identifies defective sensors and communications channels. Validated data from the analytic tools is supplied to a number of knowledge-based systems. These systems will be responsible for the control, protection, and optimization of the electric power system.

  13. Improve power quality of coal mine power network based on gray system theory

    Institute of Scientific and Technical Information of China (English)

    ZHU En-guo; YANG Gong-xun; XU Shu-ge; MA Gui-cun

    2007-01-01

    Unified Power Quality Controller(UPQC) was proposed to comprehensively improve power quality of coal mine power network and its basic structure and operation principle was introduced. In order to overcome time lag of Active Power Filter(APF) in compensating harmonic and reactive current, a novel method based on gray system theory was proposed to predict harmonic current and other distortion component. The mathematical model of component to be compensated was constructed by data sequence of distortion component, which could exactly forecast compensation signal of next period.The optimal control strategy was selected according to the principle of output signal approaching component to be compensated as near as possible. Before predicating each time the oldest data was eliminated while the latest data was added to data sequence.Then new predication model was established once again. The results show that the method can always construct mathematical model with variation of system parameters, reflect the latest state of system and not increase calculation quantity. The feasible and effective control strategy can improve power quality of coal mine power network.

  14. System-Awareness for Agent-based Power System Control

    DEFF Research Database (Denmark)

    Heussen, Kai; Saleem, Arshad; Lind, Morten

    2010-01-01

    to a more decentralized openaccess collaboration control paradigm. This shift cannot happen at once, but must fit also with current operation principles. In order to establish a scalable and transparent system control architecture, organizing principles have to be identified that allow for a smooth...

  15. Frequency Monitoring and Control during Power System Restoration Based on Wide Area Measurement System

    Directory of Open Access Journals (Sweden)

    Saber Nourizadeh

    2011-01-01

    Full Text Available Frequency control during power system restoration has not been strongly addressed. Operators are often concerned with the offline sizing of load and generation steps, but, nowadays, the introduction of Wide Area Measurement System (WAMS makes it possible to monitor the stability of power system online. The constraints of WAMS operation result in some changes in power system frequency control. This paper proposes a novel methodology for frequency control and monitoring during the early steps of power system restoration based on WAMS. Detailed load modeling is achieved based on the static load modeling approach. Power generators' modeling is also accomplished utilizing the single machine equivalent of the power system based on PMU measurements. Simulation results of the presented methodology on the 39 bus New England power system clearly show the effectiveness and applicability of the proposed method. The simulation results show that the presented approach has a completely acceptable precision and an outstanding speed with less than 0.05% error. The outstanding speed of the presented approach along with the result precision will result in a great promotion in power system restoration methodologies.

  16. Fault detection in electric power systems based on control charts

    OpenAIRE

    Kisić Emilija; Petrović Vera; Jakovljević Miroslav; Đurović Željko

    2013-01-01

    This paper analyzes the control system of the combustion process and protection from explosions in the boiler furnace of thermal power plant using the techniques of control charts. The data from old and newly introduced system for measuring under-pressure differences in boiler furnace at unit B2, TE Nikola Tesla (TENT) Obrenovac, were analyzed. The signal of undepressure difference is used for boiler protection function in thermal power plant TENT B. The results that confirm the advanta...

  17. The Power Quality Compensation Strategy for Power Distribution System Based on Hybrid Parallel Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rachid DEHINI

    2010-12-01

    Full Text Available In this paper, the main aim is to confront the performance of shunt active power filter (SAPF and the shunt hybrid active power filter (SHAPF to achieve flexibility and reliability of the filter devices. Both of the two devices used the classical proportional-integral controller for pulse generation to trigger the inventers MOSFET’s. In the adopted hybrid active filter there is a passive power filter with high power rating to filter the low order harmonies and one active filter with low power rating to filter the other high order harmonies. In order to investigate the effectiveness of (SHAPF, the studies have been accomplished using simulation with the MATLAB-SIMULINK. The results show That (SHAPF is more effective than (SAPF, and has lower cost.

  18. AC Versus DC Link Comparison Based on Power Flow Analysis of a Multimachine Power System

    Directory of Open Access Journals (Sweden)

    Mohammed Abdeljalil DJEHAF

    2014-02-01

    Full Text Available Deregulation and privatization is posing new challenges on high voltage transmission and on distributions systems as well. An increasingly liberalized market will encourage trading opportunities to be identified and developed. High voltage power electronics, such as HVDC (High Voltage Direct Current and FACTS (Flexible AC Transmission Systems provide the necessary features to avoid technical problems in heavily loaded power systems; HVDC offers most advantages: it can be used for system interconnection and for control of power flow as well. The major benefit of HVDC is its incorporated ability for fault-current blocking, which is not possible with synchronous AC links. In addition, HVDC can effectively support the surrounding AC systems in case of transient fault conditions and it serves as firewall against cascading disturbances. This paper presents a comparison between HVDC link and an HVAC link in a 29 Bus multimachine system, based on load flow analysis using Newton-Raphson method for the AC link case, and sequential method for the HVDC link case.

  19. Fault detection in electric power systems based on control charts

    Directory of Open Access Journals (Sweden)

    Kisić Emilija

    2013-01-01

    Full Text Available This paper analyzes the control system of the combustion process and protection from explosions in the boiler furnace of thermal power plant using the techniques of control charts. The data from old and newly introduced system for measuring under-pressure differences in boiler furnace at unit B2, TE Nikola Tesla (TENT Obrenovac, were analyzed. The signal of undepressure difference is used for boiler protection function in thermal power plant TENT B. The results that confirm the advantages of the newly introduced system of measurements are presented. A detailed discussion about the benefits and the shortcomings of the control charts application in industrial processes are given in the paper.

  20. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei;

    2016-01-01

    to its stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the...... and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close...... restoration. In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified...

  1. Enhanced power quality based single phase photovoltaic distributed generation system

    Science.gov (United States)

    Panda, Aurobinda; Pathak, M. K.; Srivastava, S. P.

    2016-08-01

    This article presents a novel control strategy for a 1-ϕ 2-level grid-tie photovoltaic (PV) inverter to enhance the power quality (PQ) of a PV distributed generation (PVDG) system. The objective is to obtain the maximum benefits from the grid-tie PV inverter by introducing current harmonics as well as reactive power compensation schemes in its control strategy, thereby controlling the PV inverter to achieve multiple functions in the PVDG system such as: (1) active power flow control between the PV inverter and the grid, (2) reactive power compensation, and (3) grid current harmonics compensation. A PQ enhancement controller (PQEC) has been designed to achieve the aforementioned objectives. The issue of underutilisation of the PV inverter in nighttime has also been addressed in this article and for the optimal use of the system; the PV inverter is used as a shunt active power filter in nighttime. A prototype model of the proposed system is developed in the laboratory, to validate the effectiveness of the control scheme, and is tested with the help of the dSPACE DS1104 platform.

  2. Power Quality Improvement in Distribution System using ANN Based Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Somlal Jarupula

    2015-02-01

    Full Text Available This paper focuses on an Artificial Neural Network (ANN controller based Shunt Active Power Filter (SAPF for mitigating the harmonics of the distribution system. To increase the performance of the conventional controller and take advantage of smart controllers, a feed forward-type (trained by a back propagation algorithm ANN-based technique is implemented in shunt active power filters for producing the controlled pulses required for IGBT inverter. The proposed approach mainly work on the principle of capacitor energy to maintain the DC link voltage of a shunt connected filter and thus reduces the transient response time when there is abrupt variation in the load. The entire power system block set model of the proposed scheme has been developed in MATLAB environment. Simulations are carried out by using MATLAB, it is noticed that the %THD is reduced to 2.27% from 29.71% by ANN controlled filter. The simulated experimental results also show that the novel control method is not only easy to be computed and implemented, but also very successful in reducing harmonics.  

  3. Power system

    Science.gov (United States)

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  4. Decision support system based on knowledge base in Guangdong nuclear power plant

    International Nuclear Information System (INIS)

    The decision support system is one of the assistant decision tools to the decision-makers, and it is a complex systematic project to found the decision support system. This paper introduces the establishing process of the decision support system in Guangdong Nuclear Power Plant based on knowledge base. The main method includes three steps. First is organizing, mining and getting the knowledge. Second is constructing the knowledge base based on RDBMS. Third is setting up the decision support system. Practice shows that this method has certain practical value. (authors)

  5. Ultrasonic power measurement system based on acousto-optic interaction

    Science.gov (United States)

    He, Liping; Zhu, Fulong; Chen, Yanming; Duan, Ke; Lin, Xinxin; Pan, Yongjun; Tao, Jiaquan

    2016-05-01

    Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of optical devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.

  6. Impact Study of PMSG-Based Wind Power Penetration on Power System Transient Stability Using EEAC Theory

    OpenAIRE

    Zhongyi Liu; Chongru Liu; Gengyin Li; Yong Liu; Yilu Liu

    2015-01-01

    Wind turbines with direct-driven permanent magnet synchronous generators (PMSGs) are widely used in wind power generation. According to the dynamic characteristics of PMSGs, an impact analysis of PMSG-based wind power penetration on the transient stability of multi-machine power systems is carried out in this paper based on the theory of extended equal area criterion (EEAC). Considering the most severe PMSG integration situation, the changes in the system’s equivalent power-angle relationship...

  7. Neuro Fuzzy System Based Condition Monitoring of Power Transformer

    Directory of Open Access Journals (Sweden)

    Anil Kumar Kori

    2012-03-01

    Full Text Available A power transformer is a static piece of apparatus with two or more windings. By electromagnetic induction, it transforms a system of alternating voltages and current into another system of alternating voltages and current of different values, of the same frequency, for the purpose of transmitting electrical power. For example, distribution transformers convert high-voltages electricity to lower voltages levels acceptable for use in home and business. A power transformer is one of the most expensive pieces of equipment in an electricity system. Monitoring the performance of a transformer is crucial in minimizing power outages through appropriate maintenance thereby reducing the total cost of operation. This idea provides the use of neural fuzzy technique in order to better predict oil conditions of a transformer. The preliminary phase is the first and most important step of a neural fuzzy modeling process. It aims to collect a set of data, which is expected to be a representative sample of the system to be modeled. In this phase, known as data processing, data are cleaned to make learning easier. This involves incorporation of all relevant domain knowledge at the level of an initial data analysis, including any sort of preliminary filtering of the observed data such as missing data treatment or feature selection. The preprocessing phase returns the data set in a structured input-output form, commonly called a training set. Once this preliminary phase is completed, the learning phase begins. This paper will focus exclusively on this second phase assuming that data have already been preprocessed. The learning phase is essentially a search, in a space of possible model configurations, of the model that best represents the power transformer testing values. As in any other search task, the learning procedure requires a search space, where the solution is to be found, and some assessment criterion to measure the quality of the solution.

  8. Hydrogen peroxide-based propulsion and power systems.

    Energy Technology Data Exchange (ETDEWEB)

    Melof, Brian Matthew; Keese, David L.; Ingram, Brian V.; Grubelich, Mark Charles; Ruffner, Judith Alison; Escapule, William Rusty

    2004-04-01

    Less toxic, storable, hypergolic propellants are desired to replace nitrogen tetroxide (NTO) and hydrazine in certain applications. Hydrogen peroxide is a very attractive replacement oxidizer, but finding acceptable replacement fuels is more challenging. The focus of this investigation is to find fuels that have short hypergolic ignition delays, high specific impulse, and desirable storage properties. The resulting hypergolic fuel/oxidizer combination would be highly desirable for virtually any high energy-density applications such as small but powerful gas generating systems, attitude control motors, or main propulsion. These systems would be implemented on platforms ranging from guided bombs to replacement of environmentally unfriendly existing systems to manned space vehicles.

  9. PLL Based Energy Efficient PV System with Fuzzy Logic Based Power Tracker for Smart Grid Applications.

    Science.gov (United States)

    Rohini, G; Jamuna, V

    2016-01-01

    This work aims at improving the dynamic performance of the available photovoltaic (PV) system and maximizing the power obtained from it by the use of cascaded converters with intelligent control techniques. Fuzzy logic based maximum power point technique is embedded on the first conversion stage to obtain the maximum power from the available PV array. The cascading of second converter is needed to maintain the terminal voltage at grid potential. The soft-switching region of three-stage converter is increased with the proposed phase-locked loop based control strategy. The proposed strategy leads to reduction in the ripple content, rating of components, and switching losses. The PV array is mathematically modeled and the system is simulated and the results are analyzed. The performance of the system is compared with the existing maximum power point tracking algorithms. The authors have endeavored to accomplish maximum power and improved reliability for the same insolation of the PV system. Hardware results of the system are also discussed to prove the validity of the simulation results.

  10. PLL Based Energy Efficient PV System with Fuzzy Logic Based Power Tracker for Smart Grid Applications

    Directory of Open Access Journals (Sweden)

    G. Rohini

    2016-01-01

    Full Text Available This work aims at improving the dynamic performance of the available photovoltaic (PV system and maximizing the power obtained from it by the use of cascaded converters with intelligent control techniques. Fuzzy logic based maximum power point technique is embedded on the first conversion stage to obtain the maximum power from the available PV array. The cascading of second converter is needed to maintain the terminal voltage at grid potential. The soft-switching region of three-stage converter is increased with the proposed phase-locked loop based control strategy. The proposed strategy leads to reduction in the ripple content, rating of components, and switching losses. The PV array is mathematically modeled and the system is simulated and the results are analyzed. The performance of the system is compared with the existing maximum power point tracking algorithms. The authors have endeavored to accomplish maximum power and improved reliability for the same insolation of the PV system. Hardware results of the system are also discussed to prove the validity of the simulation results.

  11. PLL Based Energy Efficient PV System with Fuzzy Logic Based Power Tracker for Smart Grid Applications.

    Science.gov (United States)

    Rohini, G; Jamuna, V

    2016-01-01

    This work aims at improving the dynamic performance of the available photovoltaic (PV) system and maximizing the power obtained from it by the use of cascaded converters with intelligent control techniques. Fuzzy logic based maximum power point technique is embedded on the first conversion stage to obtain the maximum power from the available PV array. The cascading of second converter is needed to maintain the terminal voltage at grid potential. The soft-switching region of three-stage converter is increased with the proposed phase-locked loop based control strategy. The proposed strategy leads to reduction in the ripple content, rating of components, and switching losses. The PV array is mathematically modeled and the system is simulated and the results are analyzed. The performance of the system is compared with the existing maximum power point tracking algorithms. The authors have endeavored to accomplish maximum power and improved reliability for the same insolation of the PV system. Hardware results of the system are also discussed to prove the validity of the simulation results. PMID:27294189

  12. A Novel Power System Reliability Predicting Model Based on PCA and RVM

    OpenAIRE

    Yuping Zheng; Guoqiang Sun; Zhinong Wei; Feifei Zhao; Yonghui Sun

    2013-01-01

    The power system reliability is an important index to evaluate the ability of power supply. According to the characteristics of the practical grid operation, this paper trains and sets up power grid reliability predicting model, based on relevance vector machine, taking the load supplying capacity of power grid and natural calamities as input variables, and the outage time of power grid failure affecting the reliability of the power supply as output variables. In the modeling process, through...

  13. A Series-LC-Filtered Active Damper with Grid Disturbance Rejection for AC Power-Electronics-Based Power Systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Pang, Ying; Loh, Poh Chiang;

    2015-01-01

    This letter proposes an active damper with a series LC filter for suppressing resonances in an ac power-electronics-based power system. The added series filter capacitor helps to withstand most of the system voltage, hence, allowing a lower rated converter to be used for implementing the active...

  14. A Wind Power and Load Prediction Based Frequency Control Approach for Wind-Diesel-Battery Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Chao Peng

    2015-01-01

    Full Text Available A frequency control approach based on wind power and load power prediction information is proposed for wind-diesel-battery hybrid power system (WDBHPS. To maintain the frequency stability by wind power and diesel generation as much as possible, a fuzzy control theory based wind and diesel power control module is designed according to wind power and load prediction information. To compensate frequency fluctuation in real time and enhance system disturbance rejection ability, a battery energy storage system real-time control module is designed based on ADRC (active disturbance rejection control. The simulation experiment results demonstrate that the proposed approach has a better disturbance rejection ability and frequency control performance compared with the traditional droop control approach.

  15. Systems Analysis Of Advanced Coal-Based Power Plants

    Science.gov (United States)

    Ferrall, Joseph F.; Jennings, Charles N.; Pappano, Alfred W.

    1988-01-01

    Report presents appraisal of integrated coal-gasification/fuel-cell power plants. Based on study comparing fuel-cell technologies with each other and with coal-based alternatives and recommends most promising ones for research and development. Evaluates capital cost, cost of electricity, fuel consumption, and conformance with environmental standards. Analyzes sensitivity of cost of electricity to changes in fuel cost, to economic assumptions, and to level of technology. Recommends further evaluation of integrated coal-gasification/fuel-cell integrated coal-gasification/combined-cycle, and pulverized-coal-fired plants. Concludes with appendixes detailing plant-performance models, subsystem-performance parameters, performance goals, cost bases, plant-cost data sheets, and plant sensitivity to fuel-cell performance.

  16. Modeling of Zeta converter based DVR system for power quality improvement

    Directory of Open Access Journals (Sweden)

    P.Velmurugan

    2014-05-01

    Full Text Available A new development of voltage control scheme for power quality improvement such as voltage sag, swell, harmonics, and transient conditions in three-phase power systems has been proposed. Faults occurring in power distribution systems or amenities can inject the voltage sag or swell. This fault can damage or affect the power transmission and distribution. For sensitive loads, the short duration of voltage sags also cause huge problems in the entire power system. In order to reduce power interruptions, this work proposes a novel Zeta converter based DVR system. This proposed scheme can quickly access the voltage sag and swell under transient condition.

  17. Design of a requirements system for decommissioning of a nuclear power plant based on systems engineering

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Seong; Park, Seung Kook; Jin, Hyung Gon; Song, Chan Ho; Choi, Jong won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The nuclear industry has required an advanced system that can manage decommissioning information ever since the Korean government decide to decommission the Gori No.1 nuclear power plant. The D and D division at KAERI has been developing a system that can secure the reliability and sustainability of the decommissioning project based on the engineering system of the KRR-2 (Korean Research Reactor-2). To establish a decommissioning information system, a WBS that needs to be managed for the decommissioning of an NPP has been extracted, and requirements management research composed of system engineering technology has progressed. This paper propose a new type of system based on systems engineering technology. Even though a decommissioning engineering system was developed through the KRR-2, we are now developing an advanced decommissioning information system because it is not easy to apply this system to a commercial nuclear power plant. An NPP decommissioning is a project requiring a high degree of safety and economic feasibility. Therefore, we have to use a systematic project management at the initial phase of the decommissioning. An advanced system can manage the decommissioning information from preparation to remediation by applying a previous system to the systems engineering technology that has been widely used in large-scale government projects. The first phase of the system has progressed the requirements needed for a decommissioning project for a full life cycle. The defined requirements will be used in various types of documents during the decommissioning preparation phase.

  18. An active damper for stabilizing power-electronics-based AC systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco;

    2014-01-01

    The interactions among the parallel grid-connected converters coupled through the grid impedance tend to result in stability and power quality problems. To address them, this paper proposes an active damper based on a high bandwidth power electronics converter. The general idea behind this propos...... tests on a three-converter-based setup are carried out. The results show that the active damper can become a promising way to stabilize the power-electronics-based ac power systems....

  19. Electric Vehicle Based Battery Storages for Future Power System Regulation Services

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2009-01-01

    supplying the reserve power requirements. This limited regulation services from conventional generators in the future power system calls for other new reserve power solutions like Electric Vehicle (EV) based battery storages. A generic aggregated EV based battery storage for long-term dynamic load frequency...

  20. Silicon Carbide Based Power Mangement and Distribution for Space Nuclear Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard, 100's kWe power management and distribution (PMAD) system for space nuclear...

  1. Regional modeling approach for analyzing harmonic stability in radial power electronics based power system

    DEFF Research Database (Denmark)

    Yoon, Changwoo; Bai, Haofeng; Wang, Xiongfei;

    2015-01-01

    Stability analysis of distributed power generation system becomes complex when there are many numbers of grid inverters in the system. In order to analyze system stability, the overall network impedance will be lumped and needs to be analyzed one by one. However, using a unified bulky transfer-fu...

  2. Real-Time Tariffs for Electric Vehicles in Wind Power based Power Systems

    DEFF Research Database (Denmark)

    Morais, Hugo; Sousa, Tiago; Silva, Marco;

    2013-01-01

    The use of Electric Vehicles (EVs) will change significantly the planning and management of power systems in a near future. This paper proposes a real-time tariff strategy for the charge process of the EVs. The main objective is to evaluate the influence of real-time tariffs in the EVs owners......’ behaviour and also the impact in load diagram. The paper proposes the energy price variation according to the relation between wind generation and power consumption. The proposed strategy was tested in two different days in the Danish power system. January 31st and August 13th 2013 were selected because...

  3. Market-based multiagent system for reconfiguration of shipboard power systems

    International Nuclear Information System (INIS)

    On ships, the electric shipboard power system (SPS) supplies electrical power to critical functions such as navigation, communication, emergency systems, and in the case of warships, weapon systems. During ship operation, some parts of the SPS may become unavailable due to damage, fault, or maintenance. For the survivability and reliability of ships, it is desired to make the SPS highly reconfigurable. This paper presents a market-based multiagent system (MAS) for the reconfiguration of radial SPS. Radial SPSs are found on majority of ships. In the proposed MAS, each agent only communicates with its neighbor agents to make the system work in a fully decentralized manner. The MAS is implemented using Java Agent Development Framework (JADE), which is fully implemented in Java and compliant with Foundation of Intelligent Physical Agents (FIPA). An SPS with two generators and four loads is used for testing the proposed MAS. The results show the proposed MAS can successfully reconfigure a radial SPS. (author)

  4. A power conditioning system for thermoelectric generator based on interleaved Boost converter with MPPT control

    DEFF Research Database (Denmark)

    Ni, L.-X; Sun, K.; Zhang, L.;

    2011-01-01

    conditioning system for TEG based on interleaved Boost converter with maximum power point tracking (MPPT) control is investigated in this paper. Since an internal resistance exists inside TEG modules, an improved perturbation and observation (P&O) MPPT control scheme with power limit is proposed to extract......The thermoelectric generation (TEG) system has its special charactristics of high stablility, low voltage and high current output, which is different from PV modules. The power conditioning system and control schemes used in PV applications cannot be directly applied to TEG applications. A power...... and effectiveness of the developed power conditioning system with the proposed control schemes....

  5. Power System Stabilizer Design Based on Model Reference Robust Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Yazdchi

    2012-04-01

    Full Text Available Power System Stabilizers (PSS are used to generate supplementary damping control signals for the excitation system in order to damp the Low Frequency Oscillations (LFO of the electric power system. The PSS is usually designed based on classical control approaches but this Conventional PSS (CPSS has some problems in power system control and stability enhancement. To overcome the drawbacks of CPSS, numerous techniques have been proposed in literatures. In this study a new method based on Model Reference Robust Fuzzy Control (MRRFC is considered to design PSS. In this new approach, in first an optimal PSS is designed in the nominal operating condition and then power system identification is used to obtain model reference of power system including optimal PSS. With changing system operating condition from the nominal condition, the error between obtained model reference and power system response in sent to a fuzzy controller and this fuzzy controller provides the stabilizing signal for damping power system oscillations just like PSS. In order to model reference identification a PID type PSS (PID-PSS is considered for damping electric power system oscillations. The parameters of this PID-PSS are tuned based on hybrid Genetic Algorithms (GA optimization method. The proposed MRRFC is evaluated against the CPSS at a single machine infinite bus power system considering system parametric uncertainties. The simulation results clearly indicate the effectiveness and validity of the proposed method.

  6. Combined cycle power unit with a binary system based on waste geothermal brine at Mutnovsk geothermal power plant

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Nikol'skii, A. I.; Semenov, V. N.

    2016-06-01

    The Russian geothermal power systems developed in the last few decades outperform their counterparts around the world in many respects. However, all Russian geothermal power stations employ steam as the geothermal fluid and discard the accompanying geothermal brine. In reality, the power of the existing Russian geothermal power stations may be increased without drilling more wells, if the waste brine is employed in combined cycle systems with steam and binary turbine units. For the example of the 50 MW Mutnovsk geothermal power plant, the optimal combined cycle power unit based on the waste geothermal brine is considered. It is of great interest to determine how the thermodynamic parameters of the secondary steam in the expansion unit and the pressure in the condenser affect the performance of the equipment in the combined cycle power unit at Mutnovsk geothermal power plant. For the utilization of the waste geothermal brine at Mutnovsk geothermal power plant, the optimal air temperature in the condensers of the combined cycle power unit is +5°C. The use of secondary steam obtained by flashing of the geothermal brine at Mutnovsk geothermal power plant 1 at a pressure of 0.2 MPa permits the generation of up to 8 MW of electric power in steam turbines and additional power of 5 MW in the turbines of the binary cycle.

  7. Nonlinear Analysis of Power System including FACTS and Custom Power Devices Based on Bifurcation Theory and Newton Methods

    OpenAIRE

    Segundo Ramírez, Juan

    2012-01-01

    This thesis presents the modeling of electric power systems including FACTS and Custom Power (CP) devices and their stability analysis through application of bifurcation theory, continuation methods, and Newton methods to compute the periodic steady state. The previous stability analyses of FACTS and Custom Power devices based on bifurcation theory using continuation methods neglected the harmonic distortion introduced by the voltage source converter (VSC). Besides, the network...

  8. WAMS Based Intelligent Operation and Control of Modern Power System with large Scale Renewable Energy Penetration

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain

    for alternative energy systems driven by the pressure to reduce carbon emission has stimulated a renewal of interest in wind power. The combined effect of growing demand and increasing level of intermittent wind energy penetration coupled with deregulated market has pushed the power system to operate close to its...... security limits. Under such scenario, progressive displacement of conventional generation by wind generation is expected to eventually lead a complex power system with least presence of central power plants. Consequently the support from conventional power plants is expected to reach its all-time low...... of complex power systems. WAMS is rapidly being implemented in power systems across the globe and is seen a means to realize smart grid at transmission system level. This thesis (industrial PhD with kk-electronic) proposes WAMS based methods to intelligently control and operate large scale wind integrated...

  9. Emergency power for fish produced in intensive, pond-based systems

    Science.gov (United States)

    Power failure in a heavily stocked and fed pond-based culture system can result in massive fish losses within minutes. Even in a conventional pond with a stand-by tractor powered aerator, the shock of a sudden loss of power can dramatically affect production resulting in mortalities and reduced perf...

  10. Dynamic Security Assessment of Danish Power System Based on Decision Trees: Today and Tomorrow

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Liu, Leo; Chen, Zhe;

    2013-01-01

    The research work presented in this paper analyzes the impact of wind energy, phasing out of central power plants and cross border power exchange on dynamic security of Danish Power System. Contingency based decision tree (DT) approach is used to assess the dynamic security of present and future...... in DIgSILENT PowerFactory environment and applied to western Danish Power System which is passing through a phase of major transformation. The results have shown that phasing out of central power plants coupled with large scale wind energy integration and more dependence on international ties can have...... Danish Power System. Results from offline time domain simulation for large number of possible operating conditions (OC) and critical contingencies are organized to build up the database, which is then used to predict the security of present and future power system. The mentioned approach is implemented...

  11. Low power wind energy conversion system based on variable speed permanent magnet synchronous generators

    OpenAIRE

    Carranza Castillo, Oscar; Garcerá Sanfeliú, Gabriel; Figueres Amorós, Emilio; GONZÁLEZ MORALES, LUIS GERARDO

    2014-01-01

    This paper presents a low power wind energy conversion system (WECS) based on a permanent magnet synchronous generator and a high power factor (PF) rectifier. To achieve a high PF at the generator side, a power processing scheme based on a diode rectifier and a boost DC-DC converter working in discontinuous conduction mode is proposed. The proposed generator control structure is based on three cascaded control loops that regulate the generator current, the turbine speed and the amount of powe...

  12. Subcarrier and power allocation algorithm based on inter-cell interference mitigation for OFDMA system

    Institute of Scientific and Technical Information of China (English)

    ZOU Ting; DENG Gang; WANG Ying; ZHANG Ping

    2007-01-01

    This article proposes a dynamic subcarrier and power allocation algorithm for multicell orthogonal frequency division multiple access (OFDMA) downlink system, based on inter-cell interference (ICI) mitigation. Different from other ICI mitigation schemes, which pay little attention to power allocation in the system, the proposed algorithm assigns channels to each user, based on proportional-fair (PF) scheduling and ICI coordination, whereas allocating power is based on link gain distribution and the loading bit based on adaptive modulation and coding (AMC) in base transceiver station (BTS). Simulation results show that the algorithm yields better performance for data services under fast fading.

  13. Impact Study of PMSG-Based Wind Power Penetration on Power System Transient Stability Using EEAC Theory

    Directory of Open Access Journals (Sweden)

    Zhongyi Liu

    2015-11-01

    Full Text Available Wind turbines with direct-driven permanent magnet synchronous generators (PMSGs are widely used in wind power generation. According to the dynamic characteristics of PMSGs, an impact analysis of PMSG-based wind power penetration on the transient stability of multi-machine power systems is carried out in this paper based on the theory of extended equal area criterion (EEAC. Considering the most severe PMSG integration situation, the changes in the system’s equivalent power-angle relationships after integrating PMSGs are studied in detail. The system’s equivalent mechanical input power and the fault period electrical output power curves are found to be mainly affected. The analysis demonstrates that the integration of PMSGs can cause either detrimental or beneficial effects on the system transient stability. It is determined by several factors, including the selection of the synchronous generators used to balance wind power, the reactive power control mode of PMSGs and the wind power penetration level. Two different simulation systems are also adopted to verify the analysis results.

  14. Z-Source-Inverter-Based Flexible Distributed Generation System Solution for Grid Power Quality Improvement

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Vilathgamuwa, D. M.; Loh, Poh Chiang;

    2009-01-01

    Distributed generation (DG) systems are usually connected to the grid using power electronic converters. Power delivered from such DG sources depends on factors like energy availability and load demand. The converters used in power conversion do not operate with their full capacity all the time......-stage buck-boost inverter, recently proposed Z-source inverter (ZSI) is a good candidate for future DG systems. This paper presents a controller design for a ZSI-based DG system to improve power quality of distribution systems. The proposed control method is tested with simulation results obtained using...

  15. Power System Stabilizer Based on Robust H∞ Controller for Low Frequency Operating Range

    Directory of Open Access Journals (Sweden)

    Ali Mohamed Yousef

    2012-05-01

    Full Text Available The aim of study is designed of Power System Stabilizer (PSS based on H4 approach for power system stabilization. The uncertainties in power system modeling and operations are considered at designing of H∞ PSS. The bounds of power system parameters are determined over a wide range of low frequency operating conditions. These bounds are used to design a robust H∞ PSS. A sample power system composed a synchronous generator connected to infinite bus through transmission line is simulated. The digital H∞ PSS can achieve good performance over a wide range of operating conditions. A comparison between power system responses at variety of operating conditions using the proposed H∞ PSS and Linear Quadratic Regulator LQR control have been done. H2 PSS is designed and compared with the proposed controller.

  16. System and method for controlling power consumption in a computer system based on user satisfaction

    Science.gov (United States)

    Yang, Lei; Dick, Robert P; Chen, Xi; Memik, Gokhan; Dinda, Peter A; Shy, Alex; Ozisikyilmaz, Berkin; Mallik, Arindam; Choudhary, Alok

    2014-04-22

    Systems and methods for controlling power consumption in a computer system. For each of a plurality of interactive applications, the method changes a frequency at which a processor of the computer system runs, receives an indication of user satisfaction, determines a relationship between the changed frequency and the user satisfaction of the interactive application, and stores the determined relationship information. The determined relationship can distinguish between different users and different interactive applications. A frequency may be selected from the discrete frequencies at which the processor of the computer system runs based on the determined relationship information for a particular user and a particular interactive application running on the processor of the computer system. The processor may be adapted to run at the selected frequency.

  17. Comparing the Power System Stabilizer Based on Sliding Mode Control with the Fuzzy Power System Stabilizer for Single Machine Infinite Bus System (SMIB

    Directory of Open Access Journals (Sweden)

    Atabak Kolabi

    2013-01-01

    Full Text Available This study compares the power system stabilizer based on sliding mode control with the fuzzy power system stabilizer for Single Machine Infinite Bus System (SMIB. Using the sliding mode control, a range is obtained for the changes in system parameters; and a stabilizer is designed to have a proper performance in this wide range. The purpose of designing the sliding mode stabilizer and fuzzy stabilizer is the increased stability and improving the dynamic response of the single machine system connected to the infinite bus in different working conditions. In this study, simulation results are compared in case of conventional PSS, no PSS, PSS based on sliding mode control and PSS based fuzzy logic. The results of simulations performed on the model of nonlinear system shows good performance of sliding mode controller and the Fuzzy controller. SMIB system was selected because of its simple structure, which is very useful in understanding the effects and implications of the PSS.

  18. Comparison of UPFC-Based Stabilizer and PSS Performances on Damping of Power System Oscillations

    Directory of Open Access Journals (Sweden)

    M. R. Meshkatoddini

    2009-01-01

    Full Text Available This paper establishes the linearized Phillips-Heffron model of a power system equipped with UPFC and demonstrates the application of the model in analyzing the damping effect of the UPFC and designing UPFC based stabilizer to improve power system oscillation stability. A comprehensive approach to the design of UPFC based stabilizer (power flow control, DC-voltage regulator and damping controller is presented. In this case, the multi-machine power system with UPFC is studied and an example of power system is presented. It is shown that the DC voltage contributes negative damping to power system oscillations, which is confirmed by both eigenvalue computation and nonlinear simulation. To counterattack the negative damping effect due to the DC voltage regulator, UPFC based stabilizer is designed and its effectiveness is demonstrated by both eigenvalue computation and nonlinear simulation. Then the effects of UPFC and PSS on power systems are compared. Simulation results show that the performance of UPFC based stabilizer on damping of power system is better than PSS.

  19. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    OpenAIRE

    Marc A. Rosen; Shoaib Mehmood; Bale V. Reddy

    2012-01-01

    The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel) and two coals (bituminous coal and lignite) are considered. Key system performance parameters are evaluated for various fuel combina...

  20. Power-based control of physical systems : Two case studies

    NARCIS (Netherlands)

    Garcia-Canseco, E.; Jeltsema, D.; Scherpen, J. M. A.; Ortega, R.

    2008-01-01

    It is well known that energy-balancing control is stymied by the presence of pervasive dissipation. To overcome this problem in electrical circuits, the alternative paradigm of power-shaping control was introduced in (Ortega et al., 2003)-where, as suggested by its name, stabilization is achieved sh

  1. Construction of APR1000 nuclear power information management system based on international standards

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Hwan [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Song, Deok Yong; Han, Byung Sub [Enesys Co., Daejeon (Korea, Republic of); An, Kyung Ik; Hwang, Jin Sang [PartDB Co., Daejeon (Korea, Republic of)

    2010-10-15

    In recent years, due to speedy rise of international oil prices, orders of nuclear power plant construction have been in progress by many countries to solve the stable supply of power. Our country has continued to perform nuclear power construction. As only a few developed countries like Japan and European countries have its own nuclear power construction technology, competition among them is keen. Our country has awarded the contract of UAE nuclear power plants based on the accumulated nuclear power plant construction technologies so far. In this regard, KEPCO has recognized the needs of information management system to manage nuclear power information and proceeded the implementation of nuclear power information management system for export-model

  2. Impact of wind turbine based on double feed induction generator and FACTS devices on power systems

    Directory of Open Access Journals (Sweden)

    Labiba ADJOUDJ

    2015-05-01

    Full Text Available Integration of wind turbines may have significant impacts on power system operation and generation of electricity from wind power has received considerable attention. This paper analyses the impact of integrating wind generation based on double feed induction generators (DFIG and Flexible AC Transmission System (FACTS on the voltage collapse and active losses of network IEEE 30 bus test. Therefore, we must choose among FACTS devices, those with specific applications such as maintaining the voltage at the desired value and the control of power flow, SVC is the most effective in the compensation of reactive as well as maintaining the voltage, and TCSC is the best choice for a proper control of power flow and consequently the reduction of active losses. The simulation results show clearly the effect of wind power plants and FACTS on the grid, voltage stability and power quality of electric power system.

  3. Fault tree based reliability analysis for digital reactor power control system of nuclear power plant

    International Nuclear Information System (INIS)

    Fault tree method is used for reliability analysis for reactor power control system, including uncertainty analysis and sensitive analysis. 'loss of regulation accident' top event and 'loss of effective control' top event are defined, corresponding fault tree are constructed, and contribution of hardware failure and software failure to system safety are calculated. It points out that common mode failures of software, actuator, sensor and operator's response have significant influence to system reliability in 'loss of regulation accident'; software common mode failure and operators' response have significant contribution to system reliability in 'loss of efficient control accident'. (authors)

  4. Power Forecasting of Combined Heating and Cooling Systems Based on Chaotic Time Series

    Directory of Open Access Journals (Sweden)

    Liu Hai

    2015-01-01

    Full Text Available Theoretic analysis shows that the output power of the distributed generation system is nonlinear and chaotic. And it is coupled with the microenvironment meteorological data. Chaos is an inherent property of nonlinear dynamic system. A predicator of the output power of the distributed generation system is to establish a nonlinear model of the dynamic system based on real time series in the reconstructed phase space. Firstly, chaos should be detected and quantified for the intensive studies of nonlinear systems. If the largest Lyapunov exponent is positive, the dynamical system must be chaotic. Then, the embedding dimension and the delay time are chosen based on the improved C-C method. The attractor of chaotic power time series can be reconstructed based on the embedding dimension and delay time in the phase space. By now, the neural network can be trained based on the training samples, which are observed from the distributed generation system. The neural network model will approximate the curve of output power adequately. Experimental results show that the maximum power point of the distributed generation system will be predicted based on the meteorological data. The system can be controlled effectively based on the prediction.

  5. Multi-Stage Optimization Based Automatic Voltage Control Systems Considering Wind Power Forecasting Errors

    DEFF Research Database (Denmark)

    Qin, Nan; Bak, Claus Leth; Abildgaard, Hans;

    2016-01-01

    This paper proposes an automatic voltage control (AVC) system for power systems with limited continuous voltage control capability. The objective is to minimize the operational cost over a period, which consists of the power loss in the grid, the shunt switching cost, the transformer tap change...... cost and the generator reactive power output cost. The problem is formulated in a multi-stage optimal reactive power flow (MORPF) framework, solved by the nonlinear programming techniques via a rolling process. The voltage uncertainty caused by wind power forecasting errors is considered in the optimal...... electricity control center, where study cases based on the western Danish power system demonstrate the superiority of the proposed AVC system in term of the cost minimization. Monte Carlo simulations are carried out to verify the proposed method on the robustness improvements....

  6. Chaotic improved PSO-based multi-objective optimization for minimization of power losses and L index in power systems

    International Nuclear Information System (INIS)

    Highlights: • New method for MOORPD problem using MOCIPSO and MOIPSO approaches. • Constrain-prior Pareto-dominance method is proposed to meet the constraints. • The limits of the apparent power flow of transmission line are considered. • MOORPD model is built up for MOORPD problem. • The achieved results by MOCIPSO and MOIPSO approaches are better than MOPSO method. - Abstract: Multi-objective optimal reactive power dispatch (MOORPD) seeks to not only minimize power losses, but also improve the stability of power system simultaneously. In this paper, the static voltage stability enhancement is achieved through incorporating L index in MOORPD problem. Chaotic improved PSO-based multi-objective optimization (MOCIPSO) and improved PSO-based multi-objective optimization (MOIPSO) approaches are proposed for solving complex multi-objective, mixed integer nonlinear problems such as minimization of power losses and L index in power systems simultaneously. In MOCIPSO and MOIPSO based optimization approaches, crossover operator is proposed to enhance PSO diversity and improve their global searching capability, and for MOCIPSO based optimization approach, chaotic sequences based on logistic map instead of random sequences is introduced to PSO for enhancing exploitation capability. In the two approaches, constrain-prior Pareto-dominance method (CPM) is proposed to meet the inequality constraints on state variables, the sorting and crowding distance methods are considered to maintain a well distributed Pareto optimal solutions, and moreover, fuzzy set theory is employed to extract the best compromise solution over the Pareto optimal curve. The proposed approaches have been examined and tested in the IEEE 30 bus and the IEEE 57 bus power systems. The performances of MOCIPSO, MOIPSO, and multi-objective PSO (MOPSO) approaches are compared with respect to multi-objective performance measures. The simulation results are promising and confirm the ability of MOCIPSO and

  7. Modeling, control, and dispatch of photovoltaic-based power distribution systems

    Science.gov (United States)

    Carrasco, Miguel

    Small-scale generators, also called distributed generators (DGs), are primed to play a central role in future distribution systems. If properly integrated, DGs present two main advantages: (i) they help decongest existing transmission grids; and (ii) CO2 emissions are reduced since most DGs are based on renewables like wind and solar. Their integration into distribution systems is one of the main challenges the power industry will be facing in the coming years. Photovoltaic (PV) power generation represents a key technology for realizing the DG concept. In this dissertation, technical solutions are developed that enable an increased penetration of PV systems, while improving the efficiency, reliability, and power quality of power distribution grids. The presented research spans from PV array modeling, parameter identification and estimation methods, through advanced control strategies for the power electronic interfaces, to system--level optimal dispatch strategies. Simulation-based and experimental validation results show the performance of the proposed techniques.

  8. Modular VSC converter based HVDC power transmission from offshore wind power plant: Compared to the conventional HVAC system

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Kim Høj;

    2010-01-01

    The size of wind power plants (WPPs), both physical and in terms of power rating, is rapidly growing. More and more WPPs are commissioned as offshore as well as the distances from the WPP to the coast are increasing. The problems associated with long HVAC sea-cables are well documented. Alternative...... power transmission options with HVDC systems are under consideration. In this paper, a comparison between a conventional HVAC transmission system and a HVDC system equipped with modular voltage source converters is provided. The comparison is based on the total energy transmission capability...... and the energy losses. A complete procedure of evaluating the energy transmission as well as losses in both systems are presented. A brief discussion about the limitations of HVAC transmission is also included in the paper together with advantages and disadvantages of both systems....

  9. The future of GPS-based electric power system measurements, operation and control

    Energy Technology Data Exchange (ETDEWEB)

    Rizy, D.T. [Oak Ridge National Lab., TN (United States); Wilson, R.E. [Western Area Power Administration, Golden, CO (United States); Martin, K.E.; Litzenberger, W.H. [Bonneville Power Administration, Portland, OR (United States); Hauer, J.F. [Pacific Northwest National Lab., Richland, WA (United States); Overholt, P.N. [Dept. of Energy, Washington, DC (United States); Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1998-11-01

    Much of modern society is powered by inexpensive and reliable electricity delivered by a complex and elaborate electric power network. Electrical utilities are currently using the Global Positioning System-NAVSTAR (GPS) timekeeping to improve the network`s reliability. Currently, GPS synchronizes the clocks on dynamic recorders and aids in post-mortem analysis of network disturbances. Two major projects have demonstrated the use of GPS-synchronized power system measurements. In 1992, the Electric Power Research Institute`s (EPRI) sponsored Phase Measurements Project used a commercially available Phasor Measurements Unit (PMU) to collect GPS-synchronized measurements for analyzing power system problems. In 1995, Bonneville Power Administration (BPA) and Western Area Power Administration (WAPA) under DOE`s and EPRI`s sponsorship launched the Wide Area Measurements (WAMS) project. WAMS demonstrated GPS-synchronized measurements over a large area of their power networks and demonstrated the networking of GPS-based measurement systems in BPA and WAPA. The phasor measurement technology has also been used to conduct dynamic power system tests. During these tests, a large dynamic resistor was inserted to simulate a small power system disturbance.

  10. Eigenvalue-based harmonic stability analysis method in inverter-fed power systems

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede;

    2015-01-01

    This paper presents an eigenvalue-based harmonic stability analysis method for inverter-fed power systems. A full-order small-signal model for a droop-controlled Distributed Generation (DG) inverter is built first, including the time delay of digital control system, inner current and voltage...... control loops, and outer droop-based power control loop. Based on the inverter model, an overall small-signal model of a two-inverter-fed system is then established, and the eigenvalue-based stability analysis is subsequently performed to assess the influence of controller parameters on the harmonic...... harmonic stability analysis method....

  11. Basic Concept and Theoretical Study of Condition-based Maintenance for Power Transmission System

    Institute of Scientific and Technical Information of China (English)

    LIMing; HAN Xueshan; YANG Ming; GUO Zhihong

    2011-01-01

    The appropriate maintenance time for the single equipment can be found easily and efficiently under the background of condition-based maintenance. However, from the perspective of the whole power system, discrepancy between equipment individual and the whole power system would appear. Once this discrepancy can not be coordinated, it will certainly cause contradiction and conflict between individual equipment and the whole system, and lose the integral efficiency. To solve this contradiction and conflicts is of significant meaning.

  12. A Flexible Fiber-Based Supercapacitor-Triboelectric-Nanogenerator Power System for Wearable Electronics.

    Science.gov (United States)

    Wang, Jie; Li, Xiuhan; Zi, Yunlong; Wang, Sihong; Li, Zhaoling; Zheng, Li; Yi, Fang; Li, Shengming; Wang, Zhong Lin

    2015-09-01

    A flexible self-charging power system is built by integrating a fiber-based supercapacitor with a fiber-based triboelectric nanogenerator for harvesting mechanical energy from human motion. The fiber-based supercapacitor exhibits outstanding electrochemical properties, owing to the excellent pseudocapacitance of well-prepared RuO2 ·xH2 O by a vapor-phase hydrothermal method as the active material. The approach is a step forward toward self-powered wearable electronics. PMID:26175123

  13. Power System Real-Time Monitoring by Using PMU-Based Robust State Estimation Method

    DEFF Research Database (Denmark)

    Zhao, Junbo; Zhang, Gexiang; Das, Kaushik;

    2016-01-01

    Accurate real-time states provided by the state estimator are critical for power system reliable operation and control. This paper proposes a novel phasor measurement unit (PMU)-based robust state estimation method (PRSEM) to real-time monitor a power system under different operation conditions......-based bad data (BD) detection method, which can handle the smearing effect and critical measurement errors, is presented. We evaluate PRSEM by using IEEE benchmark test systems and a realistic utility system. The numerical results indicate that, in short computation time, PRSEM can effectively track...... the system real-time states with good robustness and can address several kinds of BD....

  14. On power system blackout modeling and analysis based on self-organized criticality

    Institute of Scientific and Technical Information of China (English)

    MEI ShengWei; XUE AnCheng; ZHANG XueMin

    2008-01-01

    This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly, a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description, which serves as a concrete example of the proposed generalized SOC, are given. Secondly, five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally, this paper analyzes SOC in power systems, such as, the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system, and cascading failures process.

  15. On power system blackout modeling and analysis based on self-organized criticality

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly,a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description,which serves as a concrete example of the proposed generalized SOC,are given. Secondly,five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally,this paper analyzes SOC in power systems,such as,the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system,and cas-cading failures process.

  16. INTELLIGENT CONTROL SCHEMES FOR SSSC BASED DAMPING CONTROLLERS IN MULTI-MACHINE POWER SYSTEMS

    Directory of Open Access Journals (Sweden)

    D. MURALI

    2010-08-01

    Full Text Available The main aim of this paper is to damp out power system oscillations, which has been recognized as one of the major concerns in power system operation. This paper describes the damping of power oscillations by hybrid neuro-fuzzy coordinated control of Flexible AC Transmission System (FACTS based damping controllers. The advantage of this approach is that it can handle the nonlinearities, at the same time it is faster than other conventional controllers. ANFIS (Adaptive Neuro-Fuzzy Inference System is employed for the training of the proposed fuzzy logic controllers (FLC. Simulation studies are carried out in Matlab/Simulink environment to evaluate the effectiveness of the proposed neuro-fuzzy controller on multi-machine power systems installed with Static synchronous series compensator (SSSC. Results show that the proposed neuro-fuzzy intelligent controls improve the damping performance of the SSSC based damping controllers in the event of a major disturbance.

  17. A Generic Role Based Access Control Model for Wind Power Systems

    DEFF Research Database (Denmark)

    Nagarajan, Anand; Jensen, Christian D.

    2010-01-01

    The electrical power infrastructure is facing a transition from a largely centralised distribution infrastructure with a few large power plants to an increasingly distributed infrastructure that must incorporate privately owned and operated power generation units based on fuel cells or sustainable...... infrastructure in a software domain in a manufacturer independent manner as well as establishing secure communication and authenticating the other parties in electrical power infrastructures, but they do not address the problem of access control. We therefore propose a generic model for access control in wind...... power systems, which is based on the widely used role-based access control model. The proposed model is tested using a prototype designed in conformance with the standards that are in use in modern wind power infrastructure and the results are presented to determine the overhead in communication caused...

  18. Performance Analyses of Renewable and Fuel Power Supply Systems for Different Base Station Sites

    Directory of Open Access Journals (Sweden)

    Josip Lorincz

    2014-11-01

    Full Text Available Base station sites (BSSs powered with renewable energy sources have gained the attention of cellular operators during the last few years. This is because such “green” BSSs impose significant reductions in the operational expenditures (OPEX of telecom operators due to the possibility of on-site renewable energy harvesting. In this paper, the green BSSs power supply system parameters detected through remote and centralized real time sensing are presented. An implemented sensing system based on a wireless sensor network enables reliable collection and post-processing analyses of many parameters, such as: total charging/discharging current of power supply system, battery voltage and temperature, wind speed, etc. As an example, yearly sensing results for three different BSS configurations powered by solar and/or wind energy are discussed in terms of renewable energy supply (RES system performance. In the case of powering those BSS with standalone systems based on a fuel generator, the fuel consumption models expressing interdependence among the generator load and fuel consumption are proposed. This has allowed energy-efficiency comparison of the fuel powered and RES systems, which is presented in terms of the OPEX and carbon dioxide (CO2 reductions. Additionally, approaches based on different BSS air-conditioning systems and the on/off regulation of a daily fuel generator activity are proposed and validated in terms of energy and capital expenditure (CAPEX savings.

  19. System and method for high power diode based additive manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.

    2016-04-12

    A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

  20. Power estimation for intellectual property-based digital systems at the architectural level

    Directory of Open Access Journals (Sweden)

    Yaseer Arafat Durrani

    2014-09-01

    We present an efficient power macro-modeling technique at the architectural level for digital electronic systems. This technique estimates the power dissipation of intellectual property (IP components to their statistical knowledge of the primary inputs/outputs. During the power estimation method, the sequence of an input stream is generated by a genetic algorithm (GA using input metrics and the macro-model function to construct a set of functions that map the input metrics of a macro-block to its output metrics. Then, a Monte Carlo zero-delay simulation is performed and the power dissipation is predicted by a macro-model function. The most important contribution of the technique is that it allows fast power estimation of IP-based design by the simple addition of individual power consumption. This makes the power modeling of SoCs an easy task that permits evaluation of power features at the architectural level. In order to evaluate our model, we have constructed IP-based digital systems using different IP macro-blocks. In experiments with an individual IP macro-block the average error is 1–2% and for an entire IP-based system with interconnects, the error range is from 9% to 15%. The preliminary results are effective and our macro-model provides accurate power estimation.

  1. Fiber-wireless sensor system based on a power-over-fiber technique

    Science.gov (United States)

    Wang, Jin; Yan, Jing; Ding, Yanwen; Lu, Yunqing; Jiang, Jian; Wan, Hongdan; Xu, Ji

    2016-03-01

    A fiber-wireless sensor system based on a power-over-fiber technique is developed to offer a flexible, distributed sensing ability over a middle distance, especially under environments that are sensitive to electromagnetic interference. In this system, the optical energy of a high-power laser in the base station is transmitted via a fiber and then converted into electrical energy by a photovoltaic power converter (PPC) in the remote unit. This optically power-supplied remote unit operates as the coordinator in the wireless sensor network (WSN) and exchanges the sensing information with the base station via another fiber. In our demonstration system, the sensing information can be collected by a WSN 2 km away and be transmitted back. In order to improve the power supply ability of PPC, a maximum power point tracking technique is applied. More than 80% of PPC's maximum output power can be obtained. Moreover, to reduce the power consumption of the remote unit and the sensor nodes, a simple and stable low-power communication protocol is designed.

  2. Power conversion systems based on Brayton cycles for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Linares, J.I., E-mail: linares@upcomillas.es [Rafael Marino Chair on New Energy Technologies. Comillas Pontifical University, Alberto Aguilera, 25-28015 Madrid (Spain); Herranz, L.E. [Unit of Nuclear Safety Research. CIEMAT, Madrid (Spain); Moratilla, B.Y.; Serrano, I.P. [Rafael Marino Chair on New Energy Technologies. Comillas Pontifical University, Alberto Aguilera, 25-28015 Madrid (Spain)

    2011-10-15

    This paper investigates Brayton power cycles for fusion reactors. Two working fluids have been explored: helium in classical configurations and CO{sub 2} in recompression layouts (Feher cycle). Typical recuperator arrangements in both cycles have been strongly constrained by low temperature of some of the energy thermal sources from the reactor. This limitation has been overcome in two ways: with a combined architecture and with dual cycles. Combined architecture couples the Brayton cycle with a Rankine one capable of taking advantage of the thermal energy content of the working fluid after exiting the turbine stage (iso-butane and steam fitted best the conditions of the He and CO{sub 2} cycles, respectively). Dual cycles set a specific Rankine cycle to exploit the lowest quality thermal energy source, allowing usual recuperator arrangements in the Brayton cycle. The results of the analyses indicate that dual cycles could reach thermal efficiencies around 42.8% when using helium, whereas thermal performance might be even better (46.7%), if a combined CO{sub 2}-H{sub 2}O cycle was set.

  3. Stockholm Power Tech. Power systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The proceedings from this symposium is presented in six volumes: Invited speakers` sessions; Power systems; Power electronics; High-voltage technology; Electrical machines and drives; and Information and control systems. This report covers the power systems volume. Separate abstracts have been prepared for 141 of the 145 papers in this volume

  4. Stockholm Power Tech. Power systems

    International Nuclear Information System (INIS)

    The proceedings from this symposium is presented in six volumes: Invited speakers' sessions; Power systems; Power electronics; High-voltage technology; Electrical machines and drives; and Information and control systems. This report covers the power systems volume. Separate abstracts have been prepared for 141 of the 145 papers in this volume

  5. Injection Based Dynamic Power Management and a Policy for Multiprocessor Systems

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2013-01-01

    Full Text Available Power consumption has become a critical issue in designing computer systems. Dynamic power management is an approach that aims to reduce power consumption at system level by selectively placing components into low power states. Time-out and prediction based policies are often adopted in practical systems. However, they have to accurately determine the time in low power state and otherwise the saved power consumption is not worth the loss of performance. In this paper, a power management for multiprocessor systems is proposed to optimally reduce the power consumption of multiple processors. The key feature of the proposed power management is that how long to place a processor into low power state is determined in advance but not decided when a processor becomes idle. Thus, many off-time quanta are pre-determined beforehand. The proposed power management schedules the off-time quanta to processors and a processor is placed into low power state if an off-time quantum is assigned to it. It seems that processors execute special tasks which just reduce the power supplied to them. Hence, the off-time quanta are also named sleep tasks, which are virtual and injected into the original task traffic. By doing so, the inaccurate time length of sleep tasks hardly impacts on the performance, because if a processor is blocked by a sleep task there is another one available except that all the others are blocked at the same time. Then a probabilistic policy is also proposed to optimally assign sleep tasks from the waiting queue to the processors for minimum loss of performance. In the proposed policy, high priority is given to real tasks and sleep tasks are serviced only on necessity. The analysis of the probabilistic policy is performed on a queueing model and shows that the policy is asymptotically optimal. The proposed power management and policy are further examined in empirical studies.

  6. Wind power in power systems

    CERN Document Server

    Ackermann, Thomas

    2012-01-01

    The second edition of the highly acclaimed Wind Power in Power Systems has been thoroughly revised and expanded to reflect the latest challenges associated with increasing wind power penetration levels. Since its first release, practical experiences with high wind power penetration levels have significantly increased. This book presents an overview of the lessons learned in integrating wind power into power systems and provides an outlook of the relevant issues and solutions to allow even higher wind power penetration levels. This includes the development of standard wind turbine sim

  7. A wavelet-based method for estimating damping in power systems

    OpenAIRE

    Turunen, Jukka

    2011-01-01

    This thesis presents a novel approach to electromechanical oscillation damping estimation under the ambient conditions of a power system. The power system is said to operate under the ambient conditions when it is only subjected to ever present small excitations such as constantly varying load. The damping estimation method is based on the wavelet transform and the random decrement technique. The thesis reviews the properties of the wavelet transform that are essential in damping estimat...

  8. Study on intelligent fault diagnosis system of nuclear power plants based on information fusion technique

    International Nuclear Information System (INIS)

    The technology of information fusion is used in the fault diagnosis for ship nuclear power plants in this paper. The space fusion structure is built based on fault tree expert system, NN diagnosis system, and mechanism model validation system. Not only the system deep-level knowledge, but also the shallow knowledge and the mechanism model knowledge are fully used. The simulation validation and verification showed that the information fusion diagnosis system could improve the fault diagnosis reliability effectively. (authors)

  9. Critical Nodes Identification of Power Systems Based on Controllability of Complex Networks

    Directory of Open Access Journals (Sweden)

    Yu-Shuai Li

    2015-09-01

    Full Text Available This paper proposes a new method for assessing the vulnerability of power systems based on the controllability theories of complex networks. A novel controllability index is established, taking into consideration the full controllability of the power systems, for identifying critical nodes. The network controllability model is used to calculate the minimum number of driver nodes (ND, which can solve the computable problems of the controllability of power systems. The proposed approach firstly applies the network controllability theories to research the power systems' vulnerability, which can not only effectively reveal the important nodes but also maintain full control of the power systems. Meanwhile, the method can also overcome the limitation of the hypothesis that the weight of each link or transmission line must be known compared with the existing literature. In addition, the power system is considered as a directed network and the power system model is also redefined. The proposed methodology is then used to identify critical nodes of the IEEE 118 and 300 bus system. The results show that the failure of the critical nodes can clearly increase ND and lead a significant driver node shift. Thus, the rationality and validity are verified.

  10. Transient Stability Enhancement of Power Systems by Lyapunov-Based Recurrent Neural Networks UPFC Controllers

    Science.gov (United States)

    Chu, Chia-Chi; Tsai, Hung-Chi; Chang, Wei-Neng

    A Lyapunov-based recurrent neural networks unified power flow controller (UPFC) is developed for improving transient stability of power systems. First, a simple UPFC dynamical model, composed of a controllable shunt susceptance on the shunt side and an ideal complex transformer on the series side, is utilized to analyze UPFC dynamical characteristics. Secondly, we study the control configuration of the UPFC with two major blocks: the primary control, and the supplementary control. The primary control is implemented by standard PI techniques when the power system is operated in a normal condition. The supplementary control will be effective only when the power system is subjected by large disturbances. We propose a new Lyapunov-based UPFC controller of the classical single-machine-infinite-bus system for damping enhancement. In order to consider more complicated detailed generator models, we also propose a Lyapunov-based adaptive recurrent neural network controller to deal with such model uncertainties. This controller can be treated as neural network approximations of Lyapunov control actions. In addition, this controller also provides online learning ability to adjust the corresponding weights with the back propagation algorithm built in the hidden layer. The proposed control scheme has been tested on two simple power systems. Simulation results demonstrate that the proposed control strategy is very effective for suppressing power swing even under severe system conditions.

  11. A New Remote Monitoring System Application in Laser Power Based on LabVIEW

    Directory of Open Access Journals (Sweden)

    Liu Gaoqiang

    2016-01-01

    Full Text Available In this paper, a new remote monitoring system based on LabVIEW was proposed to measure laser power automatically and remotely. This system consists of four basic components: an DH-JG2 optical power meter, a NI-USB 6008 data acquisition card, a personal computer (PC, and HP laserJet 1020 Plus printer. Since power output of laser is generally so unstable that abnormal work situation could not retroaction to inspectors right away, new system was designed to solve this problem. The detection system realized function of remote control by TCP protocol and mobile phone. Laser power curve that is measured by detection system demonstrated that the design has a good performance in real-time detection and operability.

  12. Space Nuclear Power Systems

    Science.gov (United States)

    Houts, Michael G.

    2012-01-01

    Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

  13. Static Synchronous Series Compensator Controller based on Fuzzy Logic Control for Power System Stabilization

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2011-01-01

    Full Text Available Problem statement: Modern power system consists of the complicated network of transmission lines and carries heavy demand. Thus they cause in the stability problem. Approach: Static Synchronous Series Compensator (SSSC is a power electronic based device that has the capability of controlling the power flow through a line. The series voltage injection model of SSSC is modeled into power flow equation and thus it is used to determine its control strategy. This study applies the fuzzy logic applies the SSSC to improve stability of power system. The mathematical model and control strategy of a SSSC are presented. The SSSC is represented by variable voltage injection with associate transformer leakage control to derive control strategy of SSSC. The swing curves of the three phase faulted power system without and with a SSSC is tested and compared in various cases. Results: The swing curve of the system with SSSC based fuzzy logic control has the less amplitude during the dynamic period. Conclusion: It was found from simulation results that SSSC can improve the power system oscillation after disturbance.

  14. Passivity-Based Nonlinear Excitation Control of Power Systems with Structure Matrix Reassignment

    Directory of Open Access Journals (Sweden)

    Bing Chu

    2013-08-01

    Full Text Available Passivity-based control is widely used in electronic circuit systems because it can utilize their internal structures to facilitate the controller design. In this paper, we first propose a dissipative Hamiltonian realization of power systems and discuss the disadvantages of the traditional passivity-based excitation controller. Then, a novel excitation controller is put forward to reassign the interconnection and dissipative matrix, and the corresponding Hamiltonian function. Simulation results verify that the proposed controller can effectively improve the transient stability of the power system.

  15. Integrated Multimedia Based Intelligent Group Decision Support System for Electrical Power Network

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Saxena

    2002-05-01

    Full Text Available Electrical Power Network in recent time requires an intelligent, virtual environment based decision process for the coordination of all its individual elements and the interrelated tasks. Its ultimate goal is to achieve maximum productivity and efficiency through the efficient and effective application of generation, transmission, distribution, pricing and regulatory systems. However, the complexity of electrical power network and the presence of conflicting multiple goals and objectives postulated by various groups emphasized the need of an intelligent group decision support system approach in this field. In this paper, an Integrated Multimedia based Intelligent Group Decision Support System (IM1GDSS is presented, and its main components are analyzed and discussed. In particular attention is focused on the Data Base, Model Base, Central Black Board (CBB and Multicriteria Futuristic Decision Process (MFDP module. The model base interacts with Electrical Power Network Load Forecasting and Planning (EPNLFP Module; Resource Optimization, Modeling and Simulation (ROMAS Module; Electrical Power Network Control and Evaluation Process (EPNCAEP Module, and MFDP Module through CBB for strategic planning, management control, operational planning and transaction processing. The richness of multimedia channels adds a totally new dimension in a group decision making for Electrical Power Network. The proposed IMIGDSS is a user friendly, highly interactive group decision making system, based on efficient intelligent and multimedia communication support for group discussions, retrieval of content and multi criteria decision analysis.

  16. FPGA based control system for -100 kV, 25 A Crowbarless DC power supply

    International Nuclear Information System (INIS)

    FPGA based digital control system has been developed for -100 kV, 25 A solid state modular crowbarless DC klystron bias power supply of 1 MW, 352.2 MHz RF test stand. The control system has capability to operate this power supply either in CW or pulse mode. Central controller, PSM controller and graphical user interface are key parts of this control system. Central controller monitors the status of various subsystems of this power supply like 11 kV step start unit, four numbers of main transformers each having 44 numbers of secondary windings and 176 numbers of switch power modules for deciding the number of power modules to be put ON and their duty cycles depending on the set output voltage and current. PSM controller sends appropriate control signal to the switch power modules through fibre optic lines and communicates it to the central controller. Linux based graphical user interface has been developed which enables the user to set the operating parameters along with their trip limits and displays the information of critical parameters of this power supply on a local touch screen panel. Provision for remote control and supervision is also provided through a separate PC connected to the main control system via Ethernet. The control system has capability to trip the power supply within 5 μsec in case any parameter exceeds its set limit. Suitable data logging feature is incorporated for offline fault analysis. The control system architecture along with its software protection interlocks are presented in this paper. The performance of the control system has been verified during operation of -100 kV, 25 A DC power supply with 1 MW, 352.2 MHz klystron amplifier. (author)

  17. Optimizing MEMS-Based Storage Devices for Mobile Battery-Powered Systems

    NARCIS (Netherlands)

    Khatib, Mohammed G.; Hartel, Pieter H.

    2010-01-01

    An emerging storage technology, called MEMS-based storage, promises nonvolatile storage devices with ultrahigh density, high rigidity, a small form factor, and low cost. For these reasons, MEMS-based storage devices are suitable for battery-powered mobile systems such as PDAs. For deployment in such

  18. Schematic network based on German power system to support research projects

    Energy Technology Data Exchange (ETDEWEB)

    Florez Alzate, Frey; Degner, Thomas [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany). Dept. of Network Technology and Integration; Mesa Jaramillo, Santiago [Colombian Independent System Operator, Medellin (Colombia)

    2012-07-01

    The purpose of this paper is to present the process carried out to design, collect, and validate input information, in order to implement a schematic network based on the German transmission system. This test system was developed with the purpose of assisting research and development projects, particularly those involved in the planning process required to integrate large scale renewable resources and further decommissioning of conventional power generation. An incremental modelling and a rigorous validation approach, based on multi-layer validation, is proposed. Unlike other test systems previously proposed, this system was created together with a data base model and an information management system which allows researchers to handle large amounts of information, so that they reflect the planning and operation conditions which are fundamental characteristics of an actual power system. Application examples and simulation results will be also presented. (orig.)

  19. Evaluation of a Kalman filter based power pressurizer instrument failure detection system implemented on a nuclear power plant training simulator

    International Nuclear Information System (INIS)

    The usefulness of a nuclear power plant training simulator for developing and testing modern estimation and control applications for nuclear power plants is demonstrated. A Kalman filter based instrument failure detection technique for a pressurized water reactor pressurizer is implemented on the Department of Energy N Reactor Training Simulator. This real-time failure detection method computes the first two moments (mean and variance) of each element of a normalized filter innovations vector. Failed pressurizer instrumentation can be detected by comparing these moments to the known statistical properties of the steady state, linear Kalman fitler innovations sequence. The capabilities of the detection system are evaluated using simulated plant transients and instrument failures

  20. Optimal Design of Fuzzy Based Power System Stabilizer Self Tuned by Robust Search Algorithm

    CERN Document Server

    Linda, M Mary

    2009-01-01

    In the interconnected power system network, instability problems are caused mainly by the low frequency oscillations of 0.2 to 2.5 Hz .The supplementary control signal in addition with AVR and high gain excitation systems are provided by means of Power System Stabilizer (PSS). Conventional power system stabilizers provide effective damping only on a particular operating point. But fuzzy based PSS provides good damping for a wide range of operating points. The bottlenecks faced in designing a fuzzy logic controller can be minimized by using appropriate optimization techniques like Genetic Algorithm, Particle Swam Optimization, Ant Colony Optimization etc.In this paper the membership functions of FLC are optimized by the new breed optimization technique called Genetic Algorithm. This design methodology is implemented on a Single Machine Infinite Bus (SMIB) system. Simulation results on SMIB show the effectiveness and robustness of the proposed PSS over a wide range of operating conditions and system configurati...

  1. Fuzzy wavelet plus a quantum neural network as a design base for power system stability enhancement.

    Science.gov (United States)

    Ganjefar, Soheil; Tofighi, Morteza; Karami, Hamidreza

    2015-11-01

    In this study, we introduce an indirect adaptive fuzzy wavelet neural controller (IAFWNC) as a power system stabilizer to damp inter-area modes of oscillations in a multi-machine power system. Quantum computing is an efficient method for improving the computational efficiency of neural networks, so we developed an identifier based on a quantum neural network (QNN) to train the IAFWNC in the proposed scheme. All of the controller parameters are tuned online based on the Lyapunov stability theory to guarantee the closed-loop stability. A two-machine, two-area power system equipped with a static synchronous series compensator as a series flexible ac transmission system was used to demonstrate the effectiveness of the proposed controller. The simulation and experimental results demonstrated that the proposed IAFWNC scheme can achieve favorable control performance. PMID:26363960

  2. Multi-Agent System Based Special Protection and Emergency Control Scheme against Cascading Events in Power System

    DEFF Research Database (Denmark)

    Liu, Zhou

    , according to the variations of power system operation, an overload prediction algorithm based on impedance sensitivity is proposed here to distinguish the emergency states from a remote fault. These methods combined together, which can give a fast identification of the emergency states and a clear mapping...... the proposed protection strategy in this thesis, a real time simulation platform based on Real Time Digital Simulator (RTDS) and LabVIEW is built. In this platform, the cases of cascaded blackouts are simulated on the test system simplified from the East Denmark power system. For the MAS based control system......, the distributed power system agents are set up in RTDS, while the agents in higher level are designed by LabVIEW toolkits. The case studies and simulation results demonstrate the effectiveness of real time application of the proposed MAS based special protection and emergency control scheme against the cascaded...

  3. A method for verifying and validating knowledge based systems for nuclear power plants

    International Nuclear Information System (INIS)

    Verification and validation (V and V) of computer software is an important process for power plant owners to assure safe and reliable operation when computer systems are an integral part of plant operations. New methods for V and V are needed for knowledge based systems software because this relatively new technology incorporates complex reasoning in software systems. This paper describes one approach to V and V of knowledge based systems which will be of interest to nuclear plant owners. The paper presents specific examples from the V and V of the REALM expert system

  4. Transient Stability Enhancement of Multimachine Power System Using Robust and Novel Controller Based CSC-STATCOM

    Directory of Open Access Journals (Sweden)

    Sandeep Gupta

    2015-01-01

    Full Text Available A current source converter (CSC based static synchronous compensator (STATCOM is a shunt flexible AC transmission system (FACTS device, which has a vital role as a stability support for small and large transient instability in an interconnected power network. This paper investigates the impact of a novel and robust pole-shifting controller for CSC-STATCOM to improve the transient stability of the multimachine power system. The proposed algorithm utilizes CSC based STATCOM to supply reactive power to the test system to maintain the transient stability in the event of severe contingency. Firstly, modeling and pole-shifting controller design for CSC based STATCOM are stated. After that, we show the impact of the proposed method in the multimachine power system with different disturbances. Here, applicability of the proposed scheme is demonstrated through simulation in MATLAB and the simulation results show an improvement in the transient stability of multimachine power system with CSC-STATCOM. Also clearly shown, the robustness and effectiveness of CSC-STATCOM are better rather than other shunt FACTS devices (SVC and VSC-STATCOM by comparing the results in this paper.

  5. Thermal performance analysis system based on measurement validation for nuclear power plant

    International Nuclear Information System (INIS)

    We have needs to develop a performance analysis system that can be used in nuclear power plant turbine cycle to determine whether or not to tune some equipment and when to replace the equipment. We developed NOPAS (Nuclear Operation Performance Analysis System) to aid robust performance analysis. Robustness in the performance analysis is increased by verification and validation of measured input data. We suggest new algorithm in which estimation relations for valid measurements can be obtained using correlation model between measurements and plant state. The estimation model is obtained using design data and initial acceptance measurement data of nuclear power plant. The model consists of finding most correlated state variables and mapping relations based on the model and the current state of power plant. Using this validation scheme and several adaptations from ASME PTC, we can construct more robust performance analysis system for operating nuclear power plant turbine cycle. (author)

  6. State-of-the-art research: optimal investment in market-based electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Hope, Einar; Skjeret, Frode

    2008-04-15

    The purpose of this state-of-the-art research paper is to surveying the literature on investment in market based electric power systems as a background for identifying and discussing some important issues in the optimal design and operation of such systems. A fundamental distinction has to be made between investment in the competitive part of the power system (generation and trading) on the one hand and the natural monopoly part (network infrastructure) on the other. The paper starts with a listing and discussion on market characteristics and properties of electric power and goes on to discussing performance criteria and potential sources of market failure for optimal electric power investment. After the literature survey there is a discussion of conditions under which optimal investment may occur. (author). 78 refs., figs

  7. Passivity-Based Nonlinear Excitation Control of Power Systems with Structure Matrix Reassignment

    OpenAIRE

    Bing Chu; Yanhong Liu; Chunwen Li; Jianyong Li

    2013-01-01

    Passivity-based control is widely used in electronic circuit systems because it can utilize their internal structures to facilitate the controller design. In this paper, we first propose a dissipative Hamiltonian realization of power systems and discuss the disadvantages of the traditional passivity-based excitation controller. Then, a novel excitation controller is put forward to reassign the interconnection and dissipative matrix, and the corresponding Hamiltonian function. Simulation resul...

  8. Optimal combination of energy storages for prospective power supply systems based on Renewable Energy Sources

    CERN Document Server

    Weitemeyer, Stefan; Siemer, Lars; Agert, Carsten

    2016-01-01

    Prospective power supply systems based on Renewable Energy Sources require measures to balance power generation and load at all times. The utilisation of storage devices and backup power plants is widely suggested for this purpose, whereas the best combination is still to be found. In this work, we present a modelling approach to systematically study scenarios of future power supply systems with a high share of electricity originating from wind and solar resources. By considering backup as a subordinate source of electricity with energy-only costs, the approach is independent of the actual full-load hours of the backup power plants. Applying the approach to multi-year meteorological data for Germany, cost-optimised combinations of storage devices and backup power are identified. We find that even in scenarios with significant excess generation capacities there is a need for storage devices or backup power plants with discharging power on the same order as the average load to balance the system at all times. F...

  9. Improvement of the dynamic behavior of large-scale power systems by using robust power system stabilizers based on fuzzy logic

    Directory of Open Access Journals (Sweden)

    M. Ramírez

    2015-04-01

    Full Text Available In this paper, the effect of fuzzy logic-based robust power system stabilizers on the improvement of the dynamics of a large-scale power system is investigated. The study is particularly focused on the Mexican Interconnected System and on adding damping to two critical inter-area system oscillation modes: the north-south mode and the western-peninsular mode. The fuzzy power system stabilizers (FPSSs applied here are based on a significantly reduced rule base, small number of tuning parameters, and simple control algorithm and architecture, which makes their design and implementation easier and suitable for practical applications. Non-linear time-domain simulations for a set of test cases and results from Prony Analysis verify the robustness of the designed FPSSs, as compared to conventional PSSs.

  10. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    Science.gov (United States)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2016-09-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  11. Reference concepts for a space-based hydrogen-oxygen combustion, turboalternator, burst power system

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.

    1990-07-01

    This report describes reference concepts for a hydrogen-oxygen combustion, turboalternator power system that supplies power during battle engagement to a space-based, ballistic missile defense platform. All of the concepts are open''; that is, they exhaust hydrogen or a mixture of hydrogen and water vapor into space. We considered the situation where hydrogen is presumed to be free to the power system because it is also needed to cool the platform's weapon and the situation where hydrogen is not free and its mass must be added to that of the power system. We also considered the situation where water vapor is an acceptable exhaust and the situation where it is not. The combination of these two sets of situations required four different power generation systems, and this report describes each, suggests parameter values, and estimates masses for each of the four. These reference concepts are expected to serve as a baseline'' to which other types of power systems can be compared, and they are expected to help guide technology development efforts in that they suggest parameter value ranges that will lead to optimum system designs. 7 refs., 18 figs., 5 tabs.

  12. ESB-Based Sensor Web Integration for the Prediction of Electric Power Supply System Vulnerability

    Directory of Open Access Journals (Sweden)

    Milos Bogdanovic

    2013-08-01

    Full Text Available Electric power supply companies increasingly rely on enterprise IT systems to provide them with a comprehensive view of the state of the distribution network. Within a utility-wide network, enterprise IT systems collect data from various metering devices. Such data can be effectively used for the prediction of power supply network vulnerability. The purpose of this paper is to present the Enterprise Service Bus (ESB-based Sensor Web integration solution that we have developed with the purpose of enabling prediction of power supply network vulnerability, in terms of a prediction of defect probability for a particular network element. We will give an example of its usage and demonstrate our vulnerability prediction model on data collected from two different power supply companies. The proposed solution is an extension of the GinisSense Sensor Web-based architecture for collecting, processing, analyzing, decision making and alerting based on the data received from heterogeneous data sources. In this case, GinisSense has been upgraded to be capable of operating in an ESB environment and combine Sensor Web and GIS technologies to enable prediction of electric power supply system vulnerability. Aside from electrical values, the proposed solution gathers ambient values from additional sensors installed in the existing power supply network infrastructure. GinisSense aggregates gathered data according to an adapted Omnibus data fusion model and applies decision-making logic on the aggregated data. Detected vulnerabilities are visualized to end-users through means of a specialized Web GIS application.

  13. ESB-based Sensor Web integration for the prediction of electric power supply system vulnerability.

    Science.gov (United States)

    Stoimenov, Leonid; Bogdanovic, Milos; Bogdanovic-Dinic, Sanja

    2013-08-15

    Electric power supply companies increasingly rely on enterprise IT systems to provide them with a comprehensive view of the state of the distribution network. Within a utility-wide network, enterprise IT systems collect data from various metering devices. Such data can be effectively used for the prediction of power supply network vulnerability. The purpose of this paper is to present the Enterprise Service Bus (ESB)-based Sensor Web integration solution that we have developed with the purpose of enabling prediction of power supply network vulnerability, in terms of a prediction of defect probability for a particular network element. We will give an example of its usage and demonstrate our vulnerability prediction model on data collected from two different power supply companies. The proposed solution is an extension of the GinisSense Sensor Web-based architecture for collecting, processing, analyzing, decision making and alerting based on the data received from heterogeneous data sources. In this case, GinisSense has been upgraded to be capable of operating in an ESB environment and combine Sensor Web and GIS technologies to enable prediction of electric power supply system vulnerability. Aside from electrical values, the proposed solution gathers ambient values from additional sensors installed in the existing power supply network infrastructure. GinisSense aggregates gathered data according to an adapted Omnibus data fusion model and applies decision-making logic on the aggregated data. Detected vulnerabilities are visualized to end-users through means of a specialized Web GIS application.

  14. EXTRA: A real time knowledge-based monitoring system for a nuclear power plant

    International Nuclear Information System (INIS)

    EXTRA is an expert system for industrial process control. The main objectives are diagnosis and operation aids. From a methodological point of view, EXTRA is based on a deep knowledge of the plant operation and topology and on qualitative physics principles. This system represents a considerable step forward in the field of expert-systems because of the size of the knowledge-base and the real-time requirements. A specific application of EXTRA is developed for the BUGEY unit 2 (a 900 MWe pressurized water nuclear unit) concerning the electrical power supplies. This system called ''electrical power supplies supervision'' gives diagnosis in real time of the electric incidental situation origin. A connection to a data base make the expert system able to supply operators with information concerning the consequences of the electrical power system failures on the safety systems, the equipment measurement sensors and certain automatic devices (availability, unavailability, validity, etc.). A simulation part of the system, out of real time, can help the operators or the maintenance team to prepare the withdrawal from service of electric equipment by giving information on the consequences of it, in particular, information concerning the technical specifications. The system will be independently used and managed by the operating crews and maintenance team, but a priority is given to the diagnosis real time supervision. This expert-system will be installed for the beginning of 1989. (author). 5 refs, 2 pictures

  15. Security Design of Remote Maintenance Systems for Nuclear Power Plants Based on ISO/IEC 15408

    Science.gov (United States)

    Watabe, Ryosuke; Oi, Tadashi; Endo, Yoshio

    This paper presents a security design of remote maintenance systems for nuclear power plants. Based on ISO/IEC 15408, we list assets to be protected, threats to the assets, security objectives against the threats, and security functional requirements that achieve the security objectives. Also, we show relations between the threats and the security objectives, and relations between the security objectives and the security functional requirements. As a result, we concretize a necessary and sufficient security design of remote maintenance systems for nuclear power plants that can protect the instrumentation and control system against intrusion, impersonation, tapping, obstruction and destruction.

  16. WAVELET-BASED OFDM-CDMA HIGH SPEED POWER LINE COMMUNICATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhou Lerong; Guo Jinghong; Wei Gang

    2004-01-01

    This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) based OFDM-CDMA(Code Division Multiple Access) communication systems for high speed Power Line Communication (PLC) channels.This system gives much better robustness to Inter-Channel Interference (ICI), Multi-User Interference (MUI) and noise interference, which is verified by simulation.

  17. Robust PID based power system stabiliser: Design and real-time implementation

    Energy Technology Data Exchange (ETDEWEB)

    Bevrani, Hassan [Department of Electrical and Computer Eng., University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Hiyama, Takashi [Department of Electrical and Computer Eng., Kumamoto University, Kumamoto (Japan); Bevrani, Hossein [Department of Statistics, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2011-02-15

    This paper addresses a new robust control strategy to synthesis of robust proportional-integral-derivative (PID) based power system stabilisers (PSS). The PID based PSS design problem is reduced to find an optimal gain vector via an H{infinity} static output feedback control (H{infinity}-SOF) technique, and the solution is easily carried out using a developed iterative linear matrix inequalities algorithm. To illustrate the developed approach, a real-time experiment has been performed for a longitudinal four-machine infinite-bus system using the Analog Power System Simulator at the Research Laboratory of the Kyushu Electric Power Company. The results of the proposed control strategy are compared with full-order H{infinity} and conventional PSS designs. The robust PSS is shown to maintain the robust performance and minimise the effect of disturbances properly. (author)

  18. The design and simulation of TCR(thyristor control reactor) reactive power compensation system based on Arene

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-fang; ZHANG Li; JIANG Jian-guo; WANG Ru-lin

    2004-01-01

    Inevitably, the question of reactive power compensation was aroused by applied of power electronics. Based on the study of the instantaneous reactive power theory, the designs of TCR(thyristor control reactor) thyristor control reactor reactive power compensation system and TCR single closed loop strategy was proposed. In addition, as digital simulation software, Arene was applied to simulate the Jining coal mine No.2 system. The simulation results validate that the design is effective to improve power factor and stabilization of the system.

  19. 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

    formula for the control reference is explicitly deduced in this paper considering the losses of the generator, the power electronic devices and the filter. Three control strategies are compared with the proposed method under different wind speeds and different reactive power references. The simulation......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. The...

  20. Multi-objective Decision Based Available Transfer Capability in Deregulated Power System Using Heuristic Approaches

    Science.gov (United States)

    Pasam, Gopi Krishna; Manohar, T. Gowri

    2016-09-01

    Determination of available transfer capability (ATC) requires the use of experience, intuition and exact judgment in order to meet several significant aspects in the deregulated environment. Based on these points, this paper proposes two heuristic approaches to compute ATC. The first proposed heuristic algorithm integrates the five methods known as continuation repeated power flow, repeated optimal power flow, radial basis function neural network, back propagation neural network and adaptive neuro fuzzy inference system to obtain ATC. The second proposed heuristic model is used to obtain multiple ATC values. Out of these, a specific ATC value will be selected based on a number of social, economic, deregulated environmental constraints and related to specific applications like optimization, on-line monitoring, and ATC forecasting known as multi-objective decision based optimal ATC. The validity of results obtained through these proposed methods are scrupulously verified on various buses of the IEEE 24-bus reliable test system. The results presented and derived conclusions in this paper are very useful for planning, operation, maintaining of reliable power in any power system and its monitoring in an on-line environment of deregulated power system. In this way, the proposed heuristic methods would contribute the best possible approach to assess multiple objective ATC using integrated methods.

  1. A comparative study of artificial intelligent-based maximum power point tracking for photovoltaic systems

    Science.gov (United States)

    Hussain Mutlag, Ammar; Mohamed, Azah; Shareef, Hussain

    2016-03-01

    Maximum power point tracking (MPPT) is normally required to improve the performance of photovoltaic (PV) systems. This paper presents artificial intelligent-based maximum power point tracking (AI-MPPT) by considering three artificial intelligent techniques, namely, artificial neural network (ANN), adaptive neuro fuzzy inference system with seven triangular fuzzy sets (7-tri), and adaptive neuro fuzzy inference system with seven gbell fuzzy sets. The AI-MPPT is designed for the 25 SolarTIFSTF-120P6 PV panels, with the capacity of 3 kW peak. A complete PV system is modelled using 300,000 data samples and simulated in the MATLAB/SIMULINK. The AI-MPPT has been tested under real environmental conditions for two days from 8 am to 18 pm. The results showed that the ANN based MPPT gives the most accurate performance and then followed by the 7-tri-based MPPT.

  2. Analysis of Hybrid Configuration of Coal-Based Methanol-Power Polygeneration System

    Directory of Open Access Journals (Sweden)

    Xiaosong Zhang

    2010-09-01

    Full Text Available

    A novel hybrid configuration of a coal-based polygeneration system, which bears the configuration characteristics of both parallel and sequential polygeneration systems, is proposed and investigated. Due to its configuration characteristics, the new system performs flexible production distribution (power and methanol to coordinate the performance and capacity ratio of chemical to power and facilitate peak shaving of power generation. The performance of the new system is simulated by means of Aspen Plus. The new system has a wider range of product capacity than the sequential polygeneration system, with a range of energy saving rate of 2~14%. Compared with the two other polygeneration systems the new system has better performance at each capacity ratio. Especially at a capacity ratio of chemical production to power generation of 0.5, it is about 2% higher than sequential polygeneration system and 4.5% higher than the parallel polygeneration system. Exergy analysis is performed. Better chemical energy utilization of the syngas is obtained without component adjustment but with proper recycling of the unreacted gas.

  3. Improvement of Small Signal Stability of SMIB System Using PSO and CSO based Power System Stabilizer

    Directory of Open Access Journals (Sweden)

    Y. Raghuvamsi

    2015-08-01

    Full Text Available In a power system, Low Frequency Oscillations (LFOs are dangerous and make system unstable. These oscillations are referred to small signal stability and they are mainly due to lack of damping torque. This insufficient damping torque is because of high gain and low time constant of Automatic Voltage Regulator (AVR. AVR is useful for maintaining the terminal voltage of synchronous machine as constant. While doing so, it will make the system damping torque as negative. For providing required damping torque thereby minimizing the LFOs, Power System Stabilizer is used in conjunction with AVR. In this paper for SMIB system, the stability is studied with the help of eigen values before and after placement of PSS with optimized PSS parameters using Particle Swarm Optimization (PSO and Cat Swarm Optimization (CSO. The simulation work is performed in the MATLAB/SIMULINK and corresponding results are presented and analyzed.

  4. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    Science.gov (United States)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  5. Design of Electric Power Management System in Jilin Province based on SOA

    Directory of Open Access Journals (Sweden)

    Ren Shou Ze

    2016-01-01

    Full Text Available Aiming at the problem of electric power data integration and sharing in Jilin Province, China, this paper proposed a method based on SOA which has high scalability, flexibility in strong power data and application integration. This approach establishes a web service-oriented system architecture, using SQL Server 2012 as its backend database and using C# as the programming language. And this approach has developed three kinds of terminal applications namely C/S(Client/Server, B/S(Browser /Server and M/S(Mobile/Server. Client applications send all kinds of request to the electric power cloud computing centre, meanwhile web service components receive the requests and call corresponding functions to compute, and then return the results to the original app through the internet. The results show that system achieved the target we expected and successfully realized electric power information data integration, release and sharing.

  6. Evaluation of the transient stability of power systems based on the area method

    Science.gov (United States)

    Lizalek, N. N.; Ladnova, A. N.; Tonyshev, V. F.; Popova, E. Yu.; Vtorushin, A. S.

    2013-12-01

    The prerequisites and algorithms for the analysis of stability of complex power systems by the area method are considered. Its application is based on the energy relations for the possible trajectories of the oscillatory motion of subsystems isolated for each emergency.

  7. Power MOSFET-diode-based limiter for high-frequency ultrasound systems.

    Science.gov (United States)

    Choi, Hojong; Kim, Min Gon; Cummins, Thomas M; Hwang, Jae Youn; Shung, K Kirk

    2014-10-01

    The purpose of the limiter circuits used in the ultrasound imaging systems is to pass low-voltage echo signals generated by ultrasonic transducers while preventing high-voltage short pulses transmitted by pulsers from damaging front-end circuits. Resistor-diode-based limiters (a 50 Ω resistor with a single cross-coupled diode pair) have been widely used in pulse-echo measurement and imaging system applications due to their low cost and simple architecture. However, resistor-diode-based limiters may not be suited for high-frequency ultrasound transducer applications since they produce large signal conduction losses at higher frequencies. Therefore, we propose a new limiter architecture utilizing power MOSFETs, which we call a power MOSFET-diode-based limiter. The performance of a power MOSFET-diode-based limiter was evaluated with respect to insertion loss (IL), total harmonic distortion (THD), and response time (RT). We compared these results with those of three other conventional limiter designs and showed that the power MOSFET-diode-based limiter offers the lowest IL (-1.33 dB) and fastest RT (0.10 µs) with the lowest suppressed output voltage (3.47 Vp-p) among all the limiters at 70 MHz. A pulse-echo test was performed to determine how the new limiter affected the sensitivity and bandwidth of the transducer. We found that the sensitivity and bandwidth of the transducer were 130% and 129% greater, respectively, when combined with the new power MOSFET-diode-based limiter versus the resistor-diode-based limiter. Therefore, these results demonstrate that the power MOSFET-diode-based limiter is capable of producing lower signal attenuation than the three conventional limiter designs at higher frequency operation. PMID:24626565

  8. An Integrated Framework For Power And ICT System Risk-Based Security Assessment

    Directory of Open Access Journals (Sweden)

    Emanuele Ciapessoni*,

    2014-01-01

    Full Text Available Power system (PS is exposed to natural and man-related threats which may affect the security of power supply, depending on the vulnerabilities of the system to the threats themselves as well as on the pre-fault operating conditions. Threats regard not only the power components, but also the Information and Communications Technology (ICT systems involved in PS control and protection. The resulting picture is characterized by significant uncertainties, especially as far as high impact, low probability (HILP events (typical causes of blackout events are concerned. These considerations call for the adoption of novel techniques to perform more in-depth security analyses, able to identify the contributions of the different threats and vulnerabilities to the overall operational risk. The paper describes a probabilistic risk-based methodology, developed within the European Union (EU research project AFTER (A Framework for electrical power sysTems vulnerability identification, dEfense and Restoration, aiming to perform risk assessment (by means of hazard, vulnerability, and impact analysis of the integrated power and ICT systems. Initial results of the approach are described with reference to a test system.

  9. Coordinated Control Strategies of VSC-HVDC-Based Wind Power Systems for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Xinyin Zhang

    2015-07-01

    Full Text Available The Voltage Source Converter-HVDC (VSC-HVDC system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the operation and control of VSC-HVDC and wind farm during the grid fault period is improved. The VSC-HVDC system not only provides reactive power support to the grid, but also effectively maintains the power balance and DC voltage stability by reducing wind-farm power output, without increasing the equipment investment. Correspondingly, to eliminate the influence on permanent magnet synchronous generator (PMSG-based wind turbine (WT systems, a hierarchical control strategy is designed. The speed and validity of the proposed LVRT coordinated control strategy and hierarchical control strategy were verified by MATLAB/Simulink simulations.

  10. Experimental study of a self-powered and sensing MR-damper-based vibration control system

    Science.gov (United States)

    Sapiński, Bogdan

    2011-10-01

    The paper deals with a semi-active vibration control system based on a magnetorheological (MR) damper. The study outlines the model and the structure of the system, and describes its experimental investigation. The conceptual design of this system involves harvesting energy from structural vibrations using an energy extractor based on an electromagnetic transduction mechanism (Faraday's law). The system consists of an electromagnetic induction device (EMI) prototype and an MR damper of RD-1005 series manufactured by Lord Corporation. The energy extracted is applied to control the damping characteristics of the MR damper. The model of the system was used to prove that the proposed vibration control system is feasible. The system was realized in the semi-active control strategy with energy recovery and examined through experiments in the cases where the control coil of the MR damper was voltage-supplied directly from the EMI or voltage-supplied via the rectifier, or supplied with a current control system with two feedback loops. The external loop used the sky-hook algorithm whilst the internal loop used the algorithm switching the photorelay, at the output from the rectifier. Experimental results of the proposed vibration control system were compared with those obtained for the passive system (MR damper is off-state) and for the system with an external power source (conventional system) when the control coil of the MR damper was supplied by a DC power supply and analogue voltage amplifier or a DC power supply and a photorelay. It was demonstrated that the system is able to power-supply the MR damper and can adjust itself to structural vibrations. It was also found that, since the signal of induced voltage from the EMI agrees well with that of the relative velocity signal across the damper, the device can act as a 'velocity-sign' sensor.

  11. Investigation of neural-net based control strategies for improved power system dynamic performance

    Energy Technology Data Exchange (ETDEWEB)

    Sobajic, D.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-12-31

    The ability to accurately predict the behavior of a dynamic system is of essential importance in monitoring and control of complex processes. In this regard recent advances in neural-net base system identification represent a significant step toward development and design of a new generation of control tools for increased system performance and reliability. The enabling functionality is the one of accurate representation of a model of a nonlinear and nonstationary dynamic system. This functionality provides valuable new opportunities including: (1) The ability to predict future system behavior on the basis of actual system observations, (2) On-line evaluation and display of system performance and design of early warning systems, and (3) Controller optimization for improved system performance. In this presentation, we discuss the issues involved in definition and design of learning control systems and their impact on power system control. Several numerical examples are provided for illustrative purpose.

  12. Coordinated Control Strategies of VSC-HVDC-Based Wind Power Systems for Low Voltage Ride Through

    OpenAIRE

    Xinyin Zhang; Zaijun Wu; Minqiang Hu; Xianyun Li; Ganyun Lv

    2015-01-01

    The Voltage Source Converter-HVDC (VSC-HVDC) system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT) of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the oper...

  13. Design of a nonlinear backstepping control strategy of grid interconnected wind power system based PMSG

    Science.gov (United States)

    Errami, Y.; Obbadi, A.; Sahnoun, S.; Benhmida, M.; Ouassaid, M.; Maaroufi, M.

    2016-07-01

    This paper presents nonlinear backstepping control for Wind Power Generation System (WPGS) based Permanent Magnet Synchronous Generator (PMSG) and connected to utility grid. The block diagram of the WPGS with PMSG and the grid side back-to-back converter is established with the dq frame of axes. This control scheme emphasises the regulation of the dc-link voltage and the control of the power factor at changing wind speed. Besides, in the proposed control strategy of WPGS, Maximum Power Point Tracking (MPPT) technique and pitch control are provided. The stability of the regulators is assured by employing Lyapunov analysis. The proposed control strategy for the system has been validated by MATLAB simulations under varying wind velocity and the grid fault condition. In addition, a comparison of simulation results based on the proposed Backstepping strategy and conventional Vector Control is provided.

  14. An AI-based layout design system for nuclear power plants

    International Nuclear Information System (INIS)

    An AI-based layout design system for nuclear power plants has been developed. The design of the layout of nuclear power plants is a time-consuming task requiring expertise, in which a lot of machinery and equipment must be arranged in a plant building considering various kinds of design constraints, i.e. spatial, functional, economical etc. Computer aided layout design systems have been widely expected and the application of AI technology is expected as a promising approach for the synthesis phase of this task. In this paper, we present an approach to the layout design of nuclear power plants based on a constraint-directed search; one of the AI techniques. In addition, we show how it was implemented with an object-oriented programming technique and give an example of its application. (author)

  15. Design and Implementation of SCADA System Based Power Distribution for Primary Substation (Control System

    Directory of Open Access Journals (Sweden)

    Khin Thu Zar Win

    2014-10-01

    Full Text Available SCADA stands for Supervisory Control and Data Acquisition. SCADA system is more porpular than other control system in the modern industrial processes. This research describes the automated switch control for SCADA based electrical distribution system of primary substation by using PLC. The objective of this research is to transform the manual control system to automated switch control system in Myanmar. There are four main portions in SCADA based electrical distribution system. They are automated control system, interfacing units, monitoring system and networking system. The automated control system is emphasised in this research. This system can be accomplished by using PLC ladder diagram. This automated distribution system is analyzed to develop a secure, reliabe and convenient management tool which can use remote terminal units (RTUs. The simulations based approach automated system are demonstrated in this research. According to the simulation results, the proposed automated control system using PLC are met with the desired control environment with high performance stage. This system is efficient and reliable for conventional electrical distribution system in Myanmar by using SCADA based technology.

  16. Adapting a commercial power system simulator for smart grid based system study and vulnerability assessment

    Science.gov (United States)

    Navaratne, Uditha Sudheera

    The smart grid is the future of the power grid. Smart meters and the associated network play a major role in the distributed system of the smart grid. Advance Metering Infrastructure (AMI) can enhance the reliability of the grid, generate efficient energy management opportunities and many innovations around the future smart grid. These innovations involve intense research not only on the AMI network itself but as also on the influence an AMI network can have upon the rest of the power grid. This research describes a smart meter testbed with hardware in loop that can facilitate future research in an AMI network. The smart meters in the testbed were developed such that their functionality can be customized to simulate any given scenario such as integrating new hardware components into a smart meter or developing new encryption algorithms in firmware. These smart meters were integrated into the power system simulator to simulate the power flow variation in the power grid on different AMI activities. Each smart meter in the network also provides a communication interface to the home area network. This research delivers a testbed for emulating the AMI activities and monitoring their effect on the smart grid.

  17. Web4diagnostics - experience with web-based diagnostic systems in power plants

    International Nuclear Information System (INIS)

    At SMORN 8, a new web-based diagnostic system - web4diagnostics - was presented (Kunze, 2002). During the last two years, this system became the standard diagnostic system infrastructure for internal use in Siemens Power Generation, which integrates a large data archive of measured data and capabilities for data analysis and evaluation. Besides this internal use, today some 15 power plants worldwide use web4diagnostics in their companies communication network. Essential features are: monitoring and diagnostic information are provided in HTML page format; diagnosis can be performed on any suitable machine in the computer network; a 'central diagnostic laboratory' can be configured as a virtual facility using the existing IT infrastructure; analysis results can be accessed from any computer in the information network, only a web browser is required. The system employs well-known standard diagnostic modules and also owns tools such as operational based limit surveillance, automatic report generation and automatic information in case of deviations. (author)

  18. Novel power MOSFET-based expander for high frequency ultrasound systems.

    Science.gov (United States)

    Choi, Hojong; Shung, K Kirk

    2014-01-01

    The function of an expander is to obstruct the noise signal transmitted by the pulser so that it does not pass into the transducer or receive electronics, where it can produce undesirable ring-down in an ultrasound imaging application. The most common type is a diode-based expander, which is essentially a simple diode-pair, is widely used in pulse-echo measurements and imaging applications because of its simple architecture. However, diode-based expanders may degrade the performance of ultrasonic transducers and electronic components on the receiving and transmitting sides of the ultrasound systems, respectively. Since they are non-linear devices, they cause excessive signal attenuation and noise at higher frequencies and voltages. In this paper, a new type of expander that utilizes power MOSFET components, which we call a power MOSFET-based expander, is introduced and evaluated for use in high frequency ultrasound imaging systems. The performance of a power MOSFET-based expander was evaluated relative to a diode-based expander by comparing the noise figure (NF), insertion loss (IL), total harmonic distortion (THD), response time (RT), electrical impedance (EI) and dynamic power consumption (DPC). The results showed that the power MOSFET-based expander provided better NF (0.76 dB), IL (-0.3 dB) and THD (-62.9 dB), and faster RT (82 ns) than did the diode-based expander (NF (2.6 dB), IL (-1.4 dB), THD (-56.0 dB) and RT (119 ns)) at 70 MHz. The -6 dB bandwidth and the peak-to-peak voltage of the echo signal received by the transducer using the power MOSFET-based expander improved by 17.4% and 240% compared to the diode-based expander, respectively. The new power MOSFET-based expander was shown to yield lower NF, IL and THD, faster RT and lower ring down than the diode-based expander at the expense of higher dynamic power consumption. PMID:23835308

  19. Control of a Power Generation System Based on a Dual Star Induction Generator

    OpenAIRE

    Marouani, K; Nounou, K; Benbouzid, Mohamed; Tabbache, B; Alloui, H

    2015-01-01

    This paper presents a control scheme of a power generation system based on a dual star squirrel-cage induction machine operating as an induction generator. The operating mode based on an excitation control scheme is chosen to ensure a controlled magnitude and frequency of the generator output voltage. Some preliminary simulation and experimental test results, carried out on a prototype of dual star induction machine operating as generator and supplying various loads under different conditions...

  20. PERFORMANCE EVALUATION FOR DAMPING CONTROLLERS OF POWER SYSTEMS BASED ON MULTI-AGENT MODELS

    Institute of Scientific and Technical Information of China (English)

    Ancheng XUE; Yiguang HONG

    2009-01-01

    This paper proposes a multi-layer multi-agent model for the performance evaluation of power systems, which is different from the existing multi-agent ones. To describe the impact of the structure of the networked power system, .the proposed model consists of three kinds of agents that form three layers: control agents such as the generators and associated controllers, information agents to exchange the information based on the wide area measurement system (WAMS) or transmit control signals to the power system stabilizers (PSSs), and network-node agents such as the generation nodes and load nodes connected with transmission lines. An optimal index is presented to evaluate the performance of damping controllers to the system's inter-area oscillation with respect to the information-layer topology.Then, the authors show that the inter-area information exchange is more powerful than the exchange within a given area to control the inter-area low frequency oscillation based on simulation analysis.

  1. Analysis of Stationary, Photovoltaic-based Surface Power System Designs at the Lunar South Pole

    Science.gov (United States)

    Freeh, Joshua E.

    2009-01-01

    Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.

  2. Power management system

    Science.gov (United States)

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2007-10-02

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  3. Analysis and Performance Comparison of Different Power Conditioning Systems for SMES-Based Energy Systems in Wind Turbines

    Directory of Open Access Journals (Sweden)

    Francisco J. Rodríguez

    2013-03-01

    Full Text Available Suitability of energy systems based on Superconducting Magnetic Energy Storage (SMES has been widely tested in the field of wind energy, being able to supply power in cases such as low wind speeds or voltage dips, and to store energy when there are surpluses. This article analyzes and compares the performance of three SMES-based systems that differ in the topology of power converter: a two-level Voltage Source Converter (VSC, a three-level VSC and a two-level Current Source Converter (CSC. Their performance has been improved by means of an appropriate modulation strategy. To obtain a high reliability and accuracy, a co-simulation between MATLAB/Simulink® (running the control system and PSIM® (running the power system has been executed.

  4. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  5. Residue-based Coordinated Selection and Parameter Design of Multiple Power System Stabilizers (PSSs)

    DEFF Research Database (Denmark)

    Su, Chi; Hu, Weihao; Fang, Jiakun;

    2013-01-01

    data from time domain simulations. Then a coordinated approach for multiple PSS selection and parameter design based on residue method is proposed and realized in MATLAB m-files. Particle swarm optimization (PSO) is adopted in the coordination process. The IEEE 39-bus New England system model......Residue method is a commonly used approach to design the parameters of a power system stabilizer (PSS). In this paper, a residue identification method is adopted to obtain the system residues for different input-output pairs, using the system identification toolbox in MATLAB with the measurement...... as the test system is built in DIgSIELNT PowerFactory 14.0, in which the proposed coordination method is validated by time domain simulations and modal analysis....

  6. Distributed Multi-Agent-Based Protection Scheme for Transient Stability Enhancement in Power Systems

    Science.gov (United States)

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

    2015-04-01

    This paper presents a new distributed agent-based scheme to enhance the transient stability of power systems by maintaining phase angle cohesiveness of interconnected generators through proper relay coordination with critical clearing time (CCT) information. In this distributed multi-agent infrastructure, intelligent agents represent various physical device models to provide dynamic information and energy flow among different physical processes of power systems. The agents can communicate with each other in a distributed manner with a final aim to control circuit breakers (CBs) with CCT information as this is the key issue for maintaining and enhancing the transient stability of power systems. The performance of the proposed scheme is evaluated on a standard IEEE 39-bus New England benchmark system under different large disturbances such as three-phase short-circuit faults and changes in loads within the systems. From the simulation results, it is found that the proposed scheme significantly enhances the transient stability of power systems as compared to a conventional scheme of static CB operation.

  7. Power Quality Enhancement in Wind Connected Grid System Interface Based On Static Switched Filter Compensator (SSFC

    Directory of Open Access Journals (Sweden)

    Lakshmi Prasanna Vatti

    2014-11-01

    Full Text Available Wind energy has become one of the significant alternative renewable energy resources because of its abundance and the strong drive for its commercialization. Dynamic electric load variations and wind velocity excursions cause excessive changes in the prime mover kinetic energy and the corresponding electrical power injected into the AC grid utility system. In this paper, a scheme based on the low cost static switched filter compensator (SSFC is presented for voltage sag/swell compensation, power factor improvement in distribution grid networks with the dispersed wind energy interface. The SSFC scheme is based on an intermittent switching process between two shunt capacitor banks to be one of them in parallel with the capacitor of a tuned arm filter. Two regulators based on a tri- loop dynamic error driven inter-coupled weighted modified proportional-integralderivative (PID controller which is used to modulate the PWM. The Static Switched Filter Compensation (SSFC compensation scheme which enhances the system power quality has been fully validated using MATLAB–Simulink. The effectiveness of this compensation scheme approach is demonstrated using a study case of 3 bus system. Simulation results show that there is improvement in harmonics reduction, voltage sag/swell compensation, power factor improvement at generator bus, load bus, and infinite bus respectively

  8. Computer-based control of nuclear power information systems at international level

    International Nuclear Information System (INIS)

    In most highly industrialized countries of the world information plays major role in anti-nuclear campaign. Information and discussions on nuclear power need critical and objective analysis before the structured information presentation to the public to avoid bias anti-nuclear information on one side and neglect of great risk in nuclear power. This research is developing a computer-based information system for the control of nuclear power at international level. The system is to provide easy and fast information highways for the followings: (1) Low Regulatory dose and activity limit as level of high danger for individuals and public. (2) Provision of relevant technical or scientific education among the information carriers in the nuclear power countries. The research is on fact oriented investigation about radioactivity. It also deals with fact oriented education about nuclear accidents and safety. A standard procedure for dissemination of latest findings using technical and scientific experts in nuclear technology is developed. The information highway clearly analyzes the factual information about radiation risk and nuclear energy. Radiation cannot be removed from our environment. The necessity of radiation utilizations defines nuclear energy as two-edge sword. It is therefore, possible to use computer-based information system in projecting and dissemination of expert knowledge about nuclear technology positively and also to use it in directing the public on the safety and control of the nuclear energy. The computer-based information highway for nuclear energy technology is to assist in scientific research and technological development at international level. (author)

  9. General Model to Predict Power Flow Transmitted into Laminated Beam Bases in Flexible Isolation Systems

    Institute of Scientific and Technical Information of China (English)

    NIU Junchuan; GE Peiqi; HOU Cuirong; LIM C W; SONG Kongjie

    2009-01-01

    For estimating the vibration transmission accurately and performing vibration control efficiently in isolation systems, a novel general model is presented to predict the power flow transmitted into the complicate flexible bases of laminated beams. In the model, the laminated beam bases are simulated by the first-order shear deformation laminated plate theory, which is relatively simple and economic but accurate in predicting the vibration solutions of flexible isolation systems with laminated beam bases in comparison with classical laminated beam theories and higher order theories. On the basis of the presented model, substructure technique and variational principle are employed to obtain the governing equation of the isolation system and the power flow solution. Then, the vibration characteristics of the flexible isolation systems with laminated bases are investigated. Several numerical examples are given to show the validity and efficiency of the presented model. It is concluded that the presented model is the extension of the classical one and it can obtain more accurate power flow solutions.

  10. Neural-network-based adaptive UPFC for improving transient stability performance of power system.

    Science.gov (United States)

    Mishra, Sukumar

    2006-03-01

    This paper uses the recently proposed H(infinity)-learning method, for updating the parameter of the radial basis function neural network (RBFNN) used as a control scheme for the unified power flow controller (UPFC) to improve the transient stability performance of a multimachine power system. The RBFNN uses a single neuron architecture whose input is proportional to the difference in error and the updating of its parameters is carried via a proportional value of the error. Also, the coefficients of the difference of error, error, and auxiliary signal used for improving damping performance are depicted by a genetic algorithm. The performance of the newly designed controller is evaluated in a four-machine power system subjected to different types of disturbances. The newly designed single-neuron RBFNN-based UPFC exhibits better damping performance compared to the conventional PID as well as the extended Kalman filter (EKF) updating-based RBFNN scheme, making the unstable cases stable. Its simple architecture reduces the computational burden, thereby making it attractive for real-time implementation. Also, all the machines are being equipped with the conventional power system stabilizer (PSS) to study the coordinated effect of UPFC and PSS in the system. PMID:16566472

  11. Application of Compressive Sampling in Computer Based Monitoring of Power Systems

    Directory of Open Access Journals (Sweden)

    Sarasij Das

    2014-01-01

    Full Text Available Shannon’s Nyquist theorem has always dictated the conventional signal acquisition policies. Power system is not an exception to this. As per this theory, the sampling rate must be at least twice the maximum frequency present in the signal. Recently, compressive sampling (CS theory has shown that the signals can be reconstructed from samples obtained at sub-Nyquist rate. Signal reconstruction in this theory is exact for “sparse signals” and is near exact for compressible signals provided certain conditions are satisfied. CS theory has already been applied in communication, medical imaging, MRI, radar imaging, remote sensing, computational biology, machine learning, geophysical data analysis, and so forth. CS is comparatively new in the area of computer based power system monitoring. In this paper, subareas of computer based power system monitoring where compressive sampling theory has been applied are reviewed. At first, an overview of CS is presented and then the relevant literature specific to power systems is discussed.

  12. Feasibility study of a small, thorium-based fission power system for space and terrestrial applications

    Science.gov (United States)

    Worrall, Michael Jason

    One of the current challenges facing space exploration is the creation of a power source capable of providing useful energy for the entire duration of a mission. Historically, radioisotope batteries have been used to provide load power, but this conventional system may not be capable of sustaining continuous power for longer duration missions. To remedy this, many forays into nuclear powered spacecraft have been investigated, but no robust system for long-term power generation has been found. In this study, a novel spin on the traditional fission power system that represents a potential optimum solution is presented. By utilizing mature High Temperature Gas Reactor (HTGR) technology in conjunction with the capabilities of the thorium fuel cycle, we have created a light-weight, long-term power source capable of a continuous electric power output of up to 70kW for over 15 years. This system relies upon a combination of fissile, highly-enriched uranium dioxide and fertile thorium carbide Tri-Structural Isotropic (TRISO) fuel particles embedded in a hexagonal beryllium oxide matrix. As the primary fissile material is consumed, the fertile material breeds new fissile material leading to more steady fuel loading over the lifetime of the core. Reactor control is achieved through an innovative approach to the conventional boron carbide neutron absorber by utilizing sections of borated aluminum placed in rotating control drums within the reflector. Borated aluminum allows for much smaller boron concentrations, thus eliminating the potential for 10B(n,alpha)6Li heating issues that are common in boron carbide systems. A wide range of other reactivity control systems are also investigated, such as a radially-split rotating reflector. Lastly, an extension of the design to a terrestrial based system is investigated. In this system, uranium enrichment is dropped to 20 percent in order to meet current regulations, a solid uranium-zirconium hydride fissile driver replaces the

  13. Analyzing Small Signal Stability of Power System based on Online Data by Use of SMES

    Science.gov (United States)

    Ishikawa, Hiroyuki; Shirai, Yasuyuki; Nitta, Tanzo; Shibata, Katsuhiko

    The purpose of this study is to estimate eigen-values and eigen-vectors of a power system from on-line data to evaluate the power system stability. Power system responses due to the small power modulation of known pattern from SMES (Superconducting Magnetic Energy Storage) were analyzed, and the transfer functions between the power modulation and power oscillations of generators were obtained. Eigen-values and eigen-vectors were estimated from the transfer functions. Experiments were carried out by use of a model SMES and Advanced Power System Analyzer (APSA), which is an analogue type power system simulator of Kansai Electric Power Company Inc., Japan. Changes in system condition were observed by the estimated eigen-values and eigen-vectors. Result agreed well with the resent report and digital simulation. This method gives a new application for SMES, which will be installed for improving electric power quality.

  14. ON COMPLEXITY OF POWER SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    MA Jin; CHENG Daizhan; HONG Yiguang; SUN Yuanzhang

    2003-01-01

    The power system is a classical example of complex systems. In this paper it is shown that the power industry in China is facing a tremendous challenge. The complexity in power systems is investigated as follows. First, the cascade failure in power systems is analyzed, and compared with sand-pile model. Next, we show that the agent-based modelling is a proper way for power network. Mathematically, the geometric dynamics and differential inclusion are useful tools for the stability analysis of large scale power systems. As for power market, the game theory and generalized control system model are proposed. For a complex power system, an evolutive model may be more accurate in description and analysis. Finally, certain newly developed numerical methods in the power system computation are introduced. Overall, we are convinced that the theorem of complexity, combined with modern control theory, may be the right way to answer the challenges faced by the power industry in China.

  15. Innovative biomass to power conversion systems based on cascaded supercritical CO2 Brayton cycles

    International Nuclear Information System (INIS)

    In the small to medium power range the main technologies for the conversion of biomass sources into electricity are based either on reciprocating internal combustion or organic Rankine cycle engines. Relatively low energy conversion efficiencies are obtained in both systems due to the thermodynamic losses in the conversion of biomass into syngas in the former, and to the high temperature difference in the heat transfer between combustion gases and working fluid in the latter. The aim of this paper is to demonstrate that higher efficiencies in the conversion of biomass sources into electricity can be obtained using systems based on the supercritical closed CO2 Brayton cycles (s-CO2). The s-CO2 system analysed here includes two cascaded supercritical CO2 cycles which enable to overcome the intrinsic limitation of the single cycle in the effective utilization of the whole heat available from flue gases. Both part-flow and simple supercritical CO2 cycle configurations are considered and four boiler arrangements are investigated to explore the thermodynamic performance of such systems. These power plant configurations, which were never explored in the literature for biomass conversion into electricity, are demonstrated here to be viable options to increase the energy conversion efficiency of small-to-medium biomass fired power plants. Results of the optimization procedure show that a maximum biomass to electricity conversion efficiency of 36% can be achieved using the cascaded configuration including a part flow topping cycle, which is approximately 10%-points higher than that of the existing biomass power plants in the small to medium power range. - Highlights: • Supercritical CO2 cycles are proposed for biomass to electricity conversion. • Four boiler design options are considered. • High total system efficiency is due to the part-flow cascaded configuration. • The efficiency is higher than that of other small/medium size alternative systems

  16. Sustainable Forward Operating Base Nuclear Power Evaluation (Relationship Mapping System) Users’ Manual

    Energy Technology Data Exchange (ETDEWEB)

    Not Listed

    2012-01-01

    The Sustainable Forward Operating Base (FOB) Nuclear Power Evaluation was developed by the Idaho National Laboratory Systems Engineering Department to support the Defense Advanced Research Projects Agency (DARPA) in assessing and demonstrating the viability of deploying small-scale reactors in support of military operations in theatre. This document provides a brief explanation of how to access and use the Sustainable FOB Nuclear Power Evaluation utility to view assessment results as input into developing and integrating the program elements needed to create a successful demonstration.

  17. Grid-friendly wind power systems based on the synchronverter technology

    International Nuclear Information System (INIS)

    Highlights: • A grid-friendly wind power system that uses the synchronverter technology is proposed. • Both the rotor-side and the grid-side converters act as synchronverters. • The complete generator–motor–generator system improves the performance under grid faults. • Real-time digital simulation results verify the effectiveness of the proposed method. - Abstract: Back-to-back PWM converters are becoming a realistic alternative to conventional converters in high-power wind power applications. In this paper, a control strategy based on the synchronverter technology is proposed for back-to-back PWM converters. Both converters are run as synchronverters, which are mathematically equivalent to the conventional synchronous generators. The rotor-side converter is responsible for maintaining the DC link voltage and the grid-side converter is responsible for the maximum power point tracking (MPPT). As the two converters are operated using the synchronverter technology, the formed wind power system becomes more friendly to the grid. Extensive real-time digital simulation results are presented to verify the effectiveness of the proposed method under normal operation and grid-fault scenarios

  18. A Power Allocation Algorithm Based on Cooperative Game Theory in Multi-cell OFDM Systems

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2011-11-01

    Full Text Available A centralized resource allocation algorithm in multi-cell OFDM systems is studied, which aims at improving the performance of wireless communication systems and enhancing user’s spectral efficiency on the edge of the cell. The proposed resource allocation algorithm can be divided into two steps. The first step is sub-carrier allocation based on matrix searching in single cell and the second one is joint power allocation based on cooperative game theory in multi-cell. By comparing with traditional resource allocation algorithms in multi-cell scenario, we find that the proposed algorithm has lower computational complexity and good fairness performance.

  19. Data mining diagnosis system based on rough set theory for boilers in thermal power plants

    Institute of Scientific and Technical Information of China (English)

    YANG Ping

    2006-01-01

    Large amounts of data in the SCADA systems'databases of thermal power plants have been used for monitoring,control and over-limit alarm,but not for fault diagnosis.Additional tests are often required from the technology support center of manufacturing companies to diagnose faults for large-scale equipment,although these tests are often expensive and involve some risks to equipment.Aimed at diffculfies in fault diagnosis for boilers in thermal power plants,a hybrid-intelligence data-mining system based only on acquired data in SCADA systems is structured to extract hidden diagnosis information directly from the SCADA systems' databases in thermal power plants.This makes it possible to eliminate additional tests for fault diagnosis.In the system,a focusing quantization algorithm is proposed to discretize all variables in the preparation set to improve resolution near the change between normal value to abnormal value.A reduction algorithm based on rough set theory is designed to find minimum reducts from all discrete variables in the preparation set to represent diagnosis rules succinctly.The diagnosis rules mining from SCADA systems' database are expressed directly by variables in the database,making it easy for engineers to understand and use in industry applications.A boiler fault diagnosis system is designed and realized by the proposed approach,its running results in a thermal power plant of Guangdong Province show that the system can satisfy fault diagnosis requirement of large-scale boilers and its accuracy rangers from 91% to 98% in different months.

  20. SCADA-based Operator Support System for Power Plant Equipment Fault Forecasting

    Science.gov (United States)

    Mayadevi, N.; Ushakumari, S. S.; Vinodchandra, S. S.

    2014-12-01

    Power plant equipment must be monitored closely to prevent failures from disrupting plant availability. Online monitoring technology integrated with hybrid forecasting techniques can be used to prevent plant equipment faults. A self learning rule-based expert system is proposed in this paper for fault forecasting in power plants controlled by supervisory control and data acquisition (SCADA) system. Self-learning utilizes associative data mining algorithms on the SCADA history database to form new rules that can dynamically update the knowledge base of the rule-based expert system. In this study, a number of popular associative learning algorithms are considered for rule formation. Data mining results show that the Tertius algorithm is best suited for developing a learning engine for power plants. For real-time monitoring of the plant condition, graphical models are constructed by K-means clustering. To build a time-series forecasting model, a multi layer preceptron (MLP) is used. Once created, the models are updated in the model library to provide an adaptive environment for the proposed system. Graphical user interface (GUI) illustrates the variation of all sensor values affecting a particular alarm/fault, as well as the step-by-step procedure for avoiding critical situations and consequent plant shutdown. The forecasting performance is evaluated by computing the mean absolute error and root mean square error of the predictions.

  1. Maximum Power Point Tracking of Photovoltaic power Generation System Based on Fuzzy Approximation of Operating Point Voltage with Radiation Intensity

    Directory of Open Access Journals (Sweden)

    H. Ijadi

    2012-09-01

    Full Text Available In this paper, a method to track the maximum power of solar panels based on fuzzy logic is presented. The proposed method is based on the relationship between radiation intensity and the voltage of maximum power operating point. With this relationship, at any time by measuring the light intensity, voltage can be calculated at the maximum power point by using fuzzy approximation function. In order to verify the proposed method, simulation results are presented.

  2. Open-Delta VSC Based Voltage Controller in Isolated Power Systems

    Directory of Open Access Journals (Sweden)

    Shilpi Bhattacharya

    2015-06-01

    Full Text Available This paper proposes a reduced switch Open-Delta (OD-VSC voltage controller for an standalone asynchronous generator (SAG, also known as the self-excited induction generator (SEIG,used in constant power applications such as pico hydro uncontrolled turbine driven isolated induction generator (IAG for feeding three-phase loads. The proposed reduced switch voltage controller is used to regulate and control the generator terminal voltage as it is subjected to voltage drops, dips or flickers when the isolated power system is subjected to various critical loads. Generally this purpose is carried out by a STATCOM comprising of a three-leg six-switch inverter structure. Here, in this work the DSTATCOM is realized using a three-leg four-switch insulated gate bipolar transistor (IGBT-based current controlled voltage-sourced converter (CC-VSC and a self-supporting dc bus containing two split capacitors. The proposed generating system along with the controller is modeled and simulated in MATLAB along with Simulink and power system blockset (PSB toolboxes. The system is simulated and the capability of the isolated generating system along with the reduced switch based voltage controller is presented here where the generator feeds linear and non-linear loads are investigated.

  3. System frequency support of permanent magnet synchronous generator-based wind power plant

    Science.gov (United States)

    Wu, Ziping

    With ever-increasing penetration of wind power into modern electric grids all over the world, a trending replacement of conventional synchronous generators by large wind power plants will likely result in the poor overall frequency regulation performance. On the other hand, permanent magnet synchronous generator wind Turbine System (PMSG-WTG) with full power back to back converters tends to become one of the most promising wind turbine technologies thanks to various advantages. It possesses a significant amount of kinetic energy stored in the rotating mass of turbine blades, which can be utilized to enhance the total inertia of power system. Additionally, the deloaded operation and decoupled control of active and reactive power make it possible for PMSG-WTG to provide a fast frequency regulation through full-power converter. First of all, a comprehensive and in-depth survey is conducted to analyze the motivations for incorporating the inertial response and frequency regulation of VSWT into the system frequency regulation. Besides, control classifications, fundamental control concepts and advanced control schemes implemented for auxiliary frequency support of individual WT or wind power plant are elaborated along with a comparison of the potential frequency regulation capabilities of four major types of WTs. Secondly, a Controls Advanced Research Turbine2-Permanent Magnet Synchronous Generator wind turbine (CART2-PMSG) integrated model representing the typical configuration and operation characteristics of PMSG-WT is established in Matlab/Simulink,. Meanwhile, two different rotor-side converter control schemes, including rotor speed-based control and active power-based control, are integrated into this CART2-PMSG integrated model to perform Maximum Power Point Tracking (MPPT) operation over a wide range of wind speeds, respectively. Thirdly, a novel comprehensive frequency regulation (CFR) control scheme is developed and implemented into the CART2-PMSG model based

  4. Open system architecture for condition based maintenance applied to a hydroelectric power plant

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, E.J.; Alvares, A.J. [University of Brasilia (UnB), DF (Brazil). Mechanical and Mechatronic Dept.], Emails: eamaya@unb.br, alvares@AlvaresTech.com; Gudwin, R.R. [State University of Campinas (UNICAMP), SP (Brazil). Computer Engineering and Industrial Automation Dept.], E-mail: gudwin@dca.fee.unicamp.br

    2009-07-01

    The hydroelectric power plant of Balbina is implementing a condition based maintenance system applying an open, modular and scalable integrated architecture to provide comprehensive solutions and support to the end users like operational and maintenance team. The system called SIMPREBAL (Predictive Maintenance System of Balbina) is advocate of open standards, in particular through collaborative research programmers. In the developing is clearly understands the need for both, industry standards and a simple to use software development tool chain, supporting the development of complex condition based maintenance systems with multiple partners. The Open System Architecture for Condition Based Maintenance (OSA-CBM) is a standard that consider seven hierarchic layers that represent a logic transition or performed data flow from the data acquisition layer, through the intermediates layers as signal processing, condition monitor, health assessment, prognostics and decision support, to arrive to the presentation layer. SIMPREBAL is being implementing as an OSA-CBM software framework and tool set that allows the creation of truly integrated, comprehensive maintenance solutions through the internet. This paper identifies specific benefits of the application of the OSA-CBM in comprehensive solutions of condition based maintenance for a hydroelectric power plant. (author)

  5. Design of a telemetry system based on wireless power transmission for physiological parameter monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Zhiwei, E-mail: jiayege@hotmail.com [College of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha (China); Yan, Guozheng; Zhu, Bingquan [820 Institute, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China)

    2015-04-15

    An implanted telemetry system for experimental animals with or without anaesthesia can be used to continuously monitor physiological parameters. This system is significant not only in the study of organisms but also in the evaluation of drug efficacy, artificial organs, and auxiliary devices. The system is composed of a miniature electronic capsule, a wireless power transmission module, a data-recording device, and a processing module. An electrocardiograph, a temperature sensor, and a pressure sensor are integrated in the miniature electronic capsule, in which the signals are transmitted in vitro by wireless communication after filtering, amplification, and A/D sampling. To overcome the power shortage of batteries, a wireless power transmission module based on electromagnetic induction was designed. The transmitting coil of a rectangular-section solenoid and a 3D receiving coil are proposed according to stability and safety constraints. Experiments show that at least 150 mW of power could pick up on the load in a volume of Φ10.5 mm × 11 mm, with a transmission efficiency of 2.56%. Vivisection experiments verified the feasibility of the integrated radio-telemetry system.

  6. Design of a telemetry system based on wireless power transmission for physiological parameter monitoring

    Science.gov (United States)

    Jia, Zhiwei; Yan, Guozheng; Zhu, Bingquan

    2015-04-01

    An implanted telemetry system for experimental animals with or without anaesthesia can be used to continuously monitor physiological parameters. This system is significant not only in the study of organisms but also in the evaluation of drug efficacy, artificial organs, and auxiliary devices. The system is composed of a miniature electronic capsule, a wireless power transmission module, a data-recording device, and a processing module. An electrocardiograph, a temperature sensor, and a pressure sensor are integrated in the miniature electronic capsule, in which the signals are transmitted in vitro by wireless communication after filtering, amplification, and A/D sampling. To overcome the power shortage of batteries, a wireless power transmission module based on electromagnetic induction was designed. The transmitting coil of a rectangular-section solenoid and a 3D receiving coil are proposed according to stability and safety constraints. Experiments show that at least 150 mW of power could pick up on the load in a volume of Φ10.5 mm × 11 mm, with a transmission efficiency of 2.56%. Vivisection experiments verified the feasibility of the integrated radio-telemetry system.

  7. Design of a telemetry system based on wireless power transmission for physiological parameter monitoring

    International Nuclear Information System (INIS)

    An implanted telemetry system for experimental animals with or without anaesthesia can be used to continuously monitor physiological parameters. This system is significant not only in the study of organisms but also in the evaluation of drug efficacy, artificial organs, and auxiliary devices. The system is composed of a miniature electronic capsule, a wireless power transmission module, a data-recording device, and a processing module. An electrocardiograph, a temperature sensor, and a pressure sensor are integrated in the miniature electronic capsule, in which the signals are transmitted in vitro by wireless communication after filtering, amplification, and A/D sampling. To overcome the power shortage of batteries, a wireless power transmission module based on electromagnetic induction was designed. The transmitting coil of a rectangular-section solenoid and a 3D receiving coil are proposed according to stability and safety constraints. Experiments show that at least 150 mW of power could pick up on the load in a volume of Φ10.5 mm × 11 mm, with a transmission efficiency of 2.56%. Vivisection experiments verified the feasibility of the integrated radio-telemetry system

  8. A Self-Powered Hybrid Energy Scavenging System Utilizing RF and Vibration Based Electromagnetic Harvesters

    Science.gov (United States)

    Uluşan, H.; Gharehbaghi, K.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

    2015-12-01

    This study presents a novel hybrid system that combines the power generated simultaneously by a vibration-based Electromagnetic (EM) harvester and a UHF band RF harvester. The novel hybrid scavenger interface uses a power management circuit in 180 nm CMOS technology to step-up and to regulate the combined output. At the first stage of the system, the RF harvester generates positive DC output with a 7-stage threshold compensated rectifier, while the EM harvester generates negative DC output with a self-powered AC/DC negative doubler circuit. At the second stage, the generated voltages are serially added, stepped-up with an on-chip charge pump circuit, and regulated to a typical battery voltage of 3 V. Test results indicate that the hybrid operation enables generation of 9 μW at 3 V output for a wide range of input stimulations, which could not be attained with either harvesting mode by itself. Moreover the hybrid system behaves as a typical battery, and keeps the output voltage stable at 3 V up to 18 μW of output power. The presented system is the first battery-like harvester to our knowledge that generates energy from two independent sources and regulates the output to a stable DC voltage.

  9. Reliability Evaluation of a Distribution Network with Microgrid Based on a Combined Power Generation System

    Directory of Open Access Journals (Sweden)

    Hao Bai

    2015-02-01

    Full Text Available Distributed generation (DG, battery storage (BS and electric vehicles (EVs in a microgrid constitute the combined power generation system (CPGS. A CPGS can be applied to achieve a reliable evaluation of a distribution network with microgrids. To model charging load and discharging capacity, respectively, the EVs in a CPGS can be divided into regular EVs and ruleless EVs, according to their driving behavior. Based on statistical data of gasoline-fueled vehicles and the probability distribution of charging start instant and charging time, a statistical model can be built to describe the charging load and discharging capacity of ruleless EVs. The charge and discharge curves of regular EVs can also be drawn on the basis of a daily dispatch table. The CPGS takes the charge and discharge curves of EVs, daily load and DG power generation into consideration to calculate its power supply time during islanding. Combined with fault duration, the power supply time during islanding will be used to analyze and determine the interruption times and interruption duration of loads in islands. Then the Sequential Monte Carlo method is applied to complete the reliability evaluation of the distribution system. The RBTS Bus 4 test system is utilized to illustrate the proposed technique. The effects on the system reliability of BS capacity and V2G technology, driving behavior, recharging mode and penetration of EVs are all investigated.

  10. Power system transient stability assessment based on quadratic approximation of stability region

    OpenAIRE

    Wu, FF; Ni, Y; Xue, A; Lu, Q; Mei, S.

    2005-01-01

    This paper presents an approach to estimate the Critical Clearing Time (CCT) of the multi-machine power systems based on the quadratic surface which approximates the boundary of stability region relating to the controlling unstable equilibrium point. A decomposition method is developed to obtain the coefficients of the quadratic approximation surface. The CCT is determined by the crossing point of the quadratic surface and the continuous faulted trajectory. Simulations in IEEE 9-bus and New E...

  11. A reinforcement learning based discrete supplementary control for power system transient stability enhancement

    OpenAIRE

    Glavic, M.; Ernst, Damien; Wehenkel, Louis

    2003-01-01

    This paper proposes an application of a Reinforcement Learning (RL) method to the control of a dynamic brake aimed to enhance power system transient stability. The control law of the resistive brake is in the form of switching strategies. In particular, the paper focuses on the application of a model based RL method, known as prioritized sweeping, a method proven to be suitable in applications in which computation is considered to be cheap. The curse of dimensionality problem is resolved by t...

  12. Construction of Powerful Online Search Expert System Based on Semantic Web

    Directory of Open Access Journals (Sweden)

    Yasser A. Nada

    2013-01-01

    Full Text Available In this paper we intends to build an expert system based on semantic web for online search using XML, to help users to find the desired software, and read about its features and specifications. The expert system saves user's time and effort of web searching or buying software from available libraries. Building online search expert system is ideal for capturing support knowledge to produce interactive on-line systems that provide searching details, situation-specific advice exactly like setting a session with an expert. Any person can access this interactive system from his web browser and get some questions answer in addition to precise advice which was provided by an expert. The system can provide some troubleshooting diagnose, find the right products; … Etc. The proposed system further combines aspects of three research topics (Semantic Web, Expert System and XML. Semantic web Ontology will be considered as a set of directed graphs where each node represents an item and the edges denote a term which is related to another term. Organizations can now optimize their most valuable expert knowledge through powerful interactive Web-enabled knowledge automation expert system. Online sessions emulate a conversation with a human expert asking focused questions and producing customized recommendations and advice. Hence, the main powerful point of the proposed expert system is that the skills of any domain expert will be available to everyone.

  13. Stirling engine based solar-thermal power plant with a thermo-chemical storage system

    International Nuclear Information System (INIS)

    Highlights: • The system is unaffected by climatic and seasonal variation. • Drawbacks of solar power generation are eliminated. • A constant uninterrupted output power is obtained. - Abstract: This paper describes a solar-thermal run Stirling engine based uninterrupted power generating system employing magnesium sulphate impregnated Zeolite pellets for thermal energy storage. In the proposed system, Stirling engine design is based on the average temperature difference of 480 °C, assuming the heat sink temperature equal to the ambient temperature of that place. In presence of sun, Fresnel lenses of a specially designed hybrid capsule capture solar energy and concentrate them to provide necessary heat for the operation of the engine. In absence of the sun, required heat is provided by the thermo-chemical energy stored in Zeolite pellets. Working methodologies, modelling and simulation of the proposed system along with analyses of the obtained simulated results are presented in this paper. Possible performance of the scheme at different global positions for different period of a year has also been investigated

  14. A Probabilistic Method for Determining Grid-Accommodable Wind Power Capacity Based on Multiscenario System Operation Simulation

    DEFF Research Database (Denmark)

    Xu, Qianyao; Kang, Chongqing; Zhang, Ning;

    2016-01-01

    When conducting the wind power (WP) planning, it is very important for electric power companies to evaluate the penetration limit of the grid-accommodable WP. This paper proposes a probabilistic method for determining grid-accommodable WP capacity based on the multiscenario analysis. Typical power....... The validity and effectiveness of the new method are demonstrated in two cases, i.e., the IEEE 39-bus test system and a real large power system in China, respectively....

  15. Interval Type-II Fuzzy Rule-Based STATCOM for Voltage Regulation in the Power System

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2015-08-01

    Full Text Available The static synchronous compensator (STATCOM has recently received much attention owing to its ability to stabilize power systems and mitigate voltage variations. This paper investigates a novel interval type-II fuzzy rule-based PID (proportional-integral-derivative controller for the STATCOM to mitigate bus voltage variations caused by large changes in load and the intermittent generation of photovoltaic (PV arrays. The proposed interval type-II fuzzy rule base utilizes the output of the PID controller to tune the signal applied to the STATCOM. The rules involve upper and lower membership functions that ensure the stable responses of the controlled system. The proposed method is implemented using the NEPLAN software package and MATLAB/Simulink with co-simulation. A six-bus system is used to show the effectiveness of the proposed method. Comparative studies show that the proposed method is superior to traditional PID and type-I fuzzy rule-based methods.

  16. Damping of Power Systems Oscillations by using Genetic Algorithm-Based Optimal Controller

    Directory of Open Access Journals (Sweden)

    Akram F. Bat

    2010-06-01

    Full Text Available In this paper, the power system stabilizer (PSS and Thyristor controlled phase shifter(TCPS interaction is investigated . The objective of this work is to study and design a controller capable of doing the task of damping in less economical control effort, and to globally link all controllers of national network in an optimal manner , toward smarter grids . This can be well done if a specific coordination between PSS and FACTS devices , is accomplished . Firstly, A genetic algorithm-based controller is used. Genetic Algorithm (GA is utilized to search for optimum controller parameter settings that optimize a given eigenvalue based objective function. Secondly, an optimal pole shifting, based on modern control theory for multi-input multi-output systems, is used. It requires solving first order or second order linear matrix Lyapunov equation for shifting dominant poles to much better location that guaranteed less overshoot and less settling time of system transient response following a disturbance.

  17. Improvement of Power System Stability using Artificial Neural Network based HVDC Controls

    Directory of Open Access Journals (Sweden)

    Nagu Bhookya

    2013-06-01

    Full Text Available In this paper, investigation is carried out for the improvement of power system stability by utilizing auxiliary controls for controlling HVDC power flow. The current controller model and the line dynamics are considered in the stability analysis. Transient stability analysis is done on a multi-machine system, where, a neural network controller is developed to improve the stability of the power system and to improve the response time of the controller to the changing conditions in power system. The results show the application of the neural network controller in AC-DC power systems.

  18. A decision support system based on hybrid knowledge approach for nuclear power plant operation

    International Nuclear Information System (INIS)

    This paper describes a diagnostic expert system, HYPOSS (Hybrid Knowledge Based Plant Operation Supporting System), which has been developed to support operators' decision making during the transients of nuclear power plant. HYPOSS adopts the hybrid knowledge approach which combines shallow and deep knowledge to couple the merits of both approaches. In HYPOSS, four types of knowledge are used according to the steps of diagnosis procedure: structural, functional, behavioral and heuristic knowledge. Frames and rules are adopted to represent the various knowledge types. Rule-based deduction and abduction are used for shallow and deep knowledge based reasoning respectively. The event-based operational guidelines are provided to the operator according to the diagnosed results

  19. Improvement of Power System Stability using Artificial Neural Network based HVDC Controls

    OpenAIRE

    Nagu Bhookya

    2013-01-01

    In this paper, investigation is carried out for the improvement of power system stability by utilizing auxiliary controls for controlling HVDC power flow. The current controller model and the line dynamics are considered in the stability analysis. Transient stability analysis is done on a multi-machine system, where, a neural network controller is developed to improve the stability of the power system and to improve the response time of the controller to the changing conditions in power syste...

  20. Power system transient stability assessment based on quadratic approximation of stability region

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Ancheng; Mei, Shengwei; Lu, Qiang [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Wu, Felix F.; Ni, Yixin [Center for Electrical Energy Systems, The University of Hong Kong, Hong Kong (China)

    2006-06-15

    This paper presents an approach to estimate the critical clearing time (CCT) of the multi-machine power systems based on the quadratic surface which approximates the boundary of stability region relating to the controlling unstable equilibrium point. While obtaining the coefficient matrix of the second order term of the quadratic approximation, we partition the coefficient matrix into four blocks to reduce the computation burden. The CCT is estimated by the crossing point of the quadratic approximation and the continuous faulted trajectory. Simulations in IEEE 9-bus and New England system show the effectiveness of the proposed approach. (author)

  1. Investigation on Development of Condition-Based Maintenance in Power Supply System

    Institute of Scientific and Technical Information of China (English)

    Li Minghua; Yan Zhang; Liu Chunwen; Xue Suijing; Liu Xin; Wang Ben

    2006-01-01

    @@ To improve the operation reliability of power supply system in China, it is of great significance to know the status of condition-based maintenance (CBM) in the system and accumulate related experience in recent years. This paper analyzes the current modes of detection and repair,maintenance periods, the operation status of on-line monitoring devices equipped and the existing problems of them. The results show that there exists an urgent need in intensifying the quality control and inspection of on-line monitoring products at present.

  2. Artificial Intelligence based Tuning of SVC Controller FOR CO-generated Power System

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2007-06-01

    Full Text Available The gain of SVC depends upon the type of reactive power load for optimum performance. As the load and input wind power conditions are variable, the gain setting of SVC needs to be adjusted or tuned. In this paper, an ANN based approach has been used to tune the gain parameters of the SVC controller over a wide range of load characteristics. The multi-layer feed-forward ANN tool with the error back-propagation training method is employed. Loads have been taken as the function of voltage. Analytical techniques have mostly been based on impedance load reduced network models, which suffer from several disadvantages, including inadequate load representation and lack of structural integrity. The ability of ANNs to spontaneously learn from examples, reason over inexact and fuzzy data and provide adequate and quick responses to new information not previously stored in memory has generated high performance dynamical system with unprecedented robustness. ANNs models have been developed for different hybrid power system configurations for tuning the proportional-integral controller for SVC. Transient responses of different autonomous configurations show that SVC controller with its gained tuned by the ANNs provide optimum system performance for a variety of loads.

  3. MOCA: A Low-Power, Low-Cost Motion Capture System Based on Integrated Accelerometers

    Directory of Open Access Journals (Sweden)

    Elisabetta Farella

    2007-01-01

    Full Text Available Human-computer interaction (HCI and virtual reality applications pose the challenge of enabling real-time interfaces for natural interaction. Gesture recognition based on body-mounted accelerometers has been proposed as a viable solution to translate patterns of movements that are associated with user commands, thus substituting point-and-click methods or other cumbersome input devices. On the other hand, cost and power constraints make the implementation of a natural and efficient interface suitable for consumer applications a critical task. Even though several gesture recognition solutions exist, their use in HCI context has been poorly characterized. For this reason, in this paper, we consider a low-cost/low-power wearable motion tracking system based on integrated accelerometers called motion capture with accelerometers (MOCA that we evaluated for navigation in virtual spaces. Recognition is based on a geometric algorithm that enables efficient and robust detection of rotational movements. Our objective is to demonstrate that such a low-cost and a low-power implementation is suitable for HCI applications. To this purpose, we characterized the system from both a quantitative point of view and a qualitative point of view. First, we performed static and dynamic assessment of movement recognition accuracy. Second, we evaluated the effectiveness of user experience using a 3D game application as a test bed.

  4. A comprehensive method for break points finding based on expert system for protection coordination in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Abyaneh, Hossein Askarian; Razavi, Farzad [Department of Electrical Engineering Amirkabir University of Technology (Iran); Al-Dabbagh, Majid [Hydro Tasmania Consulting (Australia); Sedeghi, Hossein [Department of Mathematics Tarbiat Moallem University, Tehran (Iran); Kazemikargar, Hossein [Zanjan University, Zanjan (Iran)

    2007-04-15

    Interconnected power systems are multi-loop structured. In such networks, the determination of settings for all overcurrent relays can be carried out in different forms and may be quite complicated. The main problem for coordination is the determination of starting points, i.e. the location of starting relays in the procedure for settings, which is referred to as break points. In this paper, a powerful approach based on expert system is applied. The rules of the expert system include network configuration, protection systems, fault levels, etc. The method is applied to two networks with different configurations, pilot protection and other protection systems. From the obtained results, it is reviled that the new method is efficient, accurate, comprehensive and more optimal than the previously used graph theory. (author)

  5. 3-Coil resonance-based wireless power transfer system for implantable electronic

    KAUST Repository

    Yi, Ying

    2013-05-01

    This paper presents a 3-coil resonance-based wireless power transfer (R-WPT) system using a single layer of inductor coil windings, in a pancake configuration, in order to obtain a compact system for implantable electronic applications. A theoretical analysis and experimental measurements in terms of quality factor Q and power transfer efficiency (PTE), was done. Our proposed 3-coil scheme can achieve a high PTE with a resonance frequency of 2.46 MHz over a transfer distance of up to 30 mm, by using two 15-mm radius implant coils. The achieved experimental PTE is more than 85%at a 5 mm separation distance, and about 50% PTE at a distance of 20 mm. © 2013 IEEE.

  6. A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks

    Institute of Scientific and Technical Information of China (English)

    Chun-hua LI; Xin-jian ZHU; Guang-yi CAO; Wan-qi HU; Sheng SUI; Ming-ruo HU

    2009-01-01

    To extract the maximum power from a photovoltaic (PV) energy system, the real-time maximum power point (MPP) of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller (FNNC), which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the fuzzy logic control algorithm.

  7. Power system dynamic stability by SSSC-based supplementary damping controller using Imperialist Competitive Algorithm

    Directory of Open Access Journals (Sweden)

    Eskandar Gholipour

    2013-02-01

    Full Text Available Power-system dynamic stability improvement by a static synchronous series compensator (SSSC based damping controller is thoroughly investigated in this paper. In order to design the optimal parameters of the controller, Imperialist Competitive Algorithm (ICA is employed to search for the optimal controller parameters. Both local and remote signals are considered in the present study and the performance of the proposed controllers with variations in the signal transmission delays has been investigated. The performances of the proposed controllers are evaluated under different disturbances for both single-machine-infinite-bus and multi-machine power systems. Finally, the results of ICA method are compared with the results of Genetic Algorithm (GA.

  8. Control of Full-Scale Converter based Wind Power Plants for damping of low frequency system oscillations

    DEFF Research Database (Denmark)

    Adamczyk, Andrzej Grzegorz; Teodorescu, Remus; Rodriguez, Pedro

    2011-01-01

    Damping of low frequency power oscillations is one of essential aspects of maintaining power system stability. In literature can be found publications on damping capability of Doubly Fed Induction Generator based wind turbines. This paper extends discussion on Wind Power Plant damping capability ...

  9. FPGA-Based Digital Current Switching Power Amplifiers Used in Magnetic Bearing Systems

    Science.gov (United States)

    Wang, Yin; Zhang, Kai; Dong, Jinping

    For a traditional two-level current switching power amplifier (PA) used in a magnetic bearing system, its current ripple is obvious. To increase its current ripple performance, three-level amplifiers are designed and their current control is generally based on analog and logical circuits. So the required hardware is complex and a performance increase from the hardware adjustment is difficult. To solve this problem, a FPGA-based digital current switching power amplifier (DCSPA) was designed. Its current ripple was obviously smaller than a two-level amplifier and its control circuit was much simpler than a tri-level amplifier with an analog control circuit. Because of the field-programmable capability of a FPGA chip used, different control algorithms including complex nonlinear algorithms could be easily implemented in the amplifier and their effects could be compared with the same hardware.

  10. Design and Construction of Distributed Control System (DCS Based Power Distribution in University Campus

    Directory of Open Access Journals (Sweden)

    Yin Yin Winn

    2014-10-01

    Full Text Available Due to the rapid development in automation system, control and monitoring are necessary for any modern system. DCS provides this control and monitoring for industrial automation. The system is designed and constructed Distributed Control System (DCS based power distribution in university campus. The research has constructed hardware and utilized Microsoft Visual Basic software in software environment using a communication network and embedded controllers. All hardware and software components have been developed and integrated together. Data exchange mechanism, USB cable has been developed between the host computer and the embedded controllers that function in two way data exchanges between the two. This system uses PIC 18F4550 microcontroller to collect electrical parameters of devices in each departments. The Graphical User Interface (GUI uses Visual Basic Software under Microsoft Visual Basic 2010 express to achieve data real-time display and status display for the loads.

  11. Low Power 24 GHz ad hoc Networking System Based on TDOA for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Melanie Jung

    2013-12-01

    Full Text Available This paper introduces the key elements of a novel low-power, high precision localization system based on Time-Difference-of-Arrival (TDOA distance measurements. The combination of multiple localizable sensor nodes, leads to an ad hoc network. Besides the localization functionality this ad hoc network has the additional advantage of a communication interface. Due to this a flexible positioning of the master station for information collection and the detection of static and mobile nodes is possible. These sensor nodes work in the 24 GHz ISM (Industrial Scientific and Medical frequency range and address several use cases and are able to improve various processes for production scheduling, logistics, quality management, medical applications and collection of geo information. The whole system design is explained briefly. Its core component is the frequency modulated continuous wave (FMCW synthesizer suitable for high performance indoor localization. This research work focuses on power and size reduction of this crucial system component. The comparison of the first and second generation of the system shows a significant size and power reduction as well as an increased precision.

  12. A fault diagnosis system for PV power station based on global partitioned gradually approximation method

    Science.gov (United States)

    Wang, S.; Zhang, X. N.; Gao, D. D.; Liu, H. X.; Ye, J.; Li, L. R.

    2016-08-01

    As the solar photovoltaic (PV) power is applied extensively, more attentions are paid to the maintenance and fault diagnosis of PV power plants. Based on analysis of the structure of PV power station, the global partitioned gradually approximation method is proposed as a fault diagnosis algorithm to determine and locate the fault of PV panels. The PV array is divided into 16x16 blocks and numbered. On the basis of modularly processing of the PV array, the current values of each block are analyzed. The mean current value of each block is used for calculating the fault weigh factor. The fault threshold is defined to determine the fault, and the shade is considered to reduce the probability of misjudgments. A fault diagnosis system is designed and implemented with LabVIEW. And it has some functions including the data realtime display, online check, statistics, real-time prediction and fault diagnosis. Through the data from PV plants, the algorithm is verified. The results show that the fault diagnosis results are accurate, and the system works well. The validity and the possibility of the system are verified by the results as well. The developed system will be benefit for the maintenance and management of large scale PV array.

  13. Partition-based Low Power DFT Methodology for System-on-chips

    Institute of Scientific and Technical Information of China (English)

    LI Yu-fei; CHEN Jian; FU Yu-zhuo

    2007-01-01

    This paper presents a partition-based Design-forTest (DFT) technique to reduce the power consumption during scan-based testing. This method is based on partitioning the chip into several independent scan domains. By enabling the scan domains alternatively, only a fraction of the entire chip will be active at the same time, leading to Iow power consumption during test. Therefore, it will significantly reduce the possibility of Electronic Migration and Overheating. In order to prevent the drop of fault coverage, wrappers on the boundaries between scan domains are employed. This paper also presents a detailed design flow based on Electronics Design Automation(EDA) tools from Synopsy(s) to implement the proposed test structure. The proposed DFT method is experimented on a state-of-theart System-on-chips (SOC). The simulation results show a significant reduction in both average and peak power dissipation without sacrificing the fault coverage and test time. This SOC has been taped out in TSMC and finished the final test in ADVANTEST.

  14. 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)

    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)

  15. Photovoltaic System Modeling with Fuzzy Logic Based Maximum Power Point Tracking Algorithm

    Directory of Open Access Journals (Sweden)

    Hasan Mahamudul

    2013-01-01

    Full Text Available This paper represents a novel modeling technique of PV module with a fuzzy logic based MPPT algorithm and boost converter in Simulink environment. The prime contributions of this work are simplification of PV modeling technique and implementation of fuzzy based MPPT system to track maximum power efficiently. The main highlighted points of this paper are to demonstrate the precise control of the duty cycle with respect to various atmospheric conditions, illustration of PV characteristic curves, and operation analysis of the converter. The proposed system has been applied for three different PV modules SOLKAR 36 W, BP MSX 60 W, and KC85T 87 W. Finally the resultant data has been compared with the theoretical prediction and company specified value to ensure the validity of the system.

  16. Economic analysis of coal-based polygeneration system for methanol and power production

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hu [Institute of Engineering Thermophysics, Chinese Academy of Sciences, P.O. Box 2706, Beijing 100080 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Jin, Hongguang; Gao, Lin; Han, Wei [Institute of Engineering Thermophysics, Chinese Academy of Sciences, P.O. Box 2706, Beijing 100080 (China)

    2010-02-15

    Polygeneration system for chemical and power co-production has been regarded as one of promising technologies to use fossil fuel more efficiently and cleanly. In this paper the thermodynamic and economic performances of three types of coal-based polygeneration system were investigated and the influence of energy saving of oxygenation systems on system economic performance was revealed. The primary cost saving ratio (PCS) is presented as a criterion, which represents the cost saving of polygeneration system compared with the single-product systems with the same products outputs, to evaluate economic advantages of polygeneration system. As a result, the system, adopting un-reacted syngas partly recycled to the methanol synthesis reactor and without the shift process, can get the optimal PCS of 11.8%, which results from the trade-off between the installed capital cost saving and the energy saving effects on the cost saving, and represents the optimal coupling relationship among chemical conversion, energy utilization and economic performance. And both of fuel price and the level of equipment capital cost affect on PCS faintly. This paper provides an evaluation method for polygeneration systems based on both technical and economic viewpoints. (author)

  17. Economic analysis of coal-based polygeneration system for methanol and power production

    International Nuclear Information System (INIS)

    Polygeneration system for chemical and power co-production has been regarded as one of promising technologies to use fossil fuel more efficiently and cleanly. In this paper the thermodynamic and economic performances of three types of coal-based polygeneration system were investigated and the influence of energy saving of oxygenation systems on system economic performance was revealed. The primary cost saving ratio (PCS) is presented as a criterion, which represents the cost saving of polygeneration system compared with the single-product systems with the same products outputs, to evaluate economic advantages of polygeneration system. As a result, the system, adopting un-reacted syngas partly recycled to the methanol synthesis reactor and without the shift process, can get the optimal PCS of 11.8%, which results from the trade-off between the installed capital cost saving and the energy saving effects on the cost saving, and represents the optimal coupling relationship among chemical conversion, energy utilization and economic performance. And both of fuel price and the level of equipment capital cost affect on PCS faintly. This paper provides an evaluation method for polygeneration systems based on both technical and economic viewpoints. (author)

  18. A coherency-based method to increase dynamic security in power systems

    Energy Technology Data Exchange (ETDEWEB)

    De Tuglie, E. [Dipartimento di Ingegneria dell' Ambiente e per lo Sviluppo Sostenibile - DIASS, Politecnico di Bari, Viale del Turismo 8, 74100 Taranto (Italy); Iannone, S.M.; Torelli, F. [Dipartimento di Elettrotecnica ed Elettronica - DEE, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy)

    2008-08-15

    Dynamic security analysis is the evaluation of the ability of a system to withstand contingencies by surviving transient conditions to acceptable steady-state operative states. When potential instability due to contingency is detected, preventive action may be desired to improve the system security. This is very important in the on-line operation of a power system, especially when the system is stability-limited. The method proposed in this paper is based on the idea that increasing coherency between generators in the transient behaviour following a system perturbation gives rise to a more stable system. In this paper, we suggest the use of the ''input-output feedback-linearization'' with a reference trajectory obtained using a system dynamic equivalent based on the centre of inertia. To quantify coherency levels a new coherency indicator has been assumed for the given reference trajectory. The result is an increasing level in coherency, critical clearing time and system stability. The method is tested on the IEEE 30 bus test system. (author)

  19. A vacuum tolerant high voltage system with a low noise and low power Cockcroft–Walton photomultiplier base

    International Nuclear Information System (INIS)

    We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft–Walton (CW) photomultiplier tube base with a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1 MeV range. We achieved a final noise level below 180μVrms for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases power distribution was also designed. This system is able to control and monitor the high voltage of each individual base

  20. Evaluation of Coordinate Compensator Structure Based on Power Injection Model for Loading Margin Enhancement in Power Systems

    Directory of Open Access Journals (Sweden)

    Reza Sedaghati

    2013-09-01

    Full Text Available In this paper, the structure of Hybrid Power Flow Controller (HPFC is proposed in order to improve static voltage stability characteristics. HPFC forms a hybrid controller using IPFC series converters as a hybrid with existing parallel and passive compensator (SVC in power system. Utilization of hybrid structures makes it possible to use converters for improving performance of both old and existing compensators in power networks. In this study, the power injection model (PIM is used to model the hybrid power flow controller in Newton load flow. The aforementioned model is simulated in MATLAB software. The P-V curves of PQ buses of a typical system are evaluated by a continuous power flow (CPF method to analyses the effect of this controller on static voltage stability characteristics. Meanwhile, SVC as existing devices in the system and UPFC and IPFC as state-of-the-art compensator devices are compared with the proposed hybrid structure. The amount of active and reactive power loss and improvement of loading limit of the system are used as main parameters in our comparison.

  1. High-Efficiency Food Production in a Renewable Energy Based Micro-Grid Power System

    Science.gov (United States)

    Bubenheim, David; Meiners, Dennis

    2016-01-01

    Controlled Environment Agriculture (CEA) systems can be used to produce high-quality, desirable food year round, and the fresh produce can positively contribute to the health and well being of residents in communities with difficult supply logistics. While CEA has many positive outcomes for a remote community, the associated high electric demands have prohibited widespread implementation in what is typically already a fully subscribed power generation and distribution system. Recent advances in CEA technologies as well as renewable power generation, storage, and micro-grid management are increasing system efficiency and expanding the possibilities for enhancing community supporting infrastructure without increasing demands for outside supplied fuels. We will present examples of how new lighting, nutrient delivery, and energy management and control systems can enable significant increases in food production efficiency while maintaining high yields in CEA. Examples from Alaskan communities where initial incorporation of renewable power generation, energy storage and grid management techniques have already reduced diesel fuel consumption for electric generation by more than 40% and expanded grid capacity will be presented. We will discuss how renewable power generation, efficient grid management to extract maximum community service per kW, and novel energy storage approaches can expand the food production, water supply, waste treatment, sanitation and other community support services without traditional increases of consumable fuels supplied from outside the community. These capabilities offer communities with a range of choices to enhance their communities. The examples represent a synergy of technology advancement efforts to develop sustainable community support systems for future space-based human habitats and practical implementation of infrastructure components to increase efficiency and enhance health and well being in remote communities today and tomorrow.

  2. A knowledge based operator support system for emergency conditions in nuclear power plants

    International Nuclear Information System (INIS)

    The control centres of the operating Indian nuclear power plants contain a large number of indicators and controls spread over many panels. In the event of onset of an emergency condition, there results a profusion of information, both numeric and symbolic. The operator may succumb to an information and cognitive overload that may be compounded by a lack of knowledge. The failure to apply knowledge and reasoning to solve an operational problem can lead to human error, which has been a major contributing factor in nuclear accidents. From the viewpoint of Artificial Intelligence, human error occurs if the operational problem requires computing resources that exceed human capabilities. The application of Artificial Intelligence, particularly expert systems, to nuclear power plant control room activities has considerable potential to reduce operator error and improve safety and reliability. The purpose of this paper is to discuss an investigative study of the feasibility of developing an operator support system incorporating Artificial Intelligence techniques. An information processing model of such a system, herein designated as Knowledge Based Operator Support System - KBOSS, employing expert systems technology, has been developed. The features of this system are described, and issues involved in its development are discussed. (author). 2 refs., 5 figs., 1 tab

  3. Structure Optimization of Stand-Alone Renewable Power Systems Based on Multi Object Function

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Cho

    2016-08-01

    Full Text Available This paper presents a methodology for the size optimization of a stand-alone hybrid PV/wind/diesel/battery system while considering the following factors: total annual cost (TAC, loss of power supply probability (LPSP, and the fuel cost of the diesel generator required by the user. A new optimization algorithm and an object function (including a penalty method are also proposed; these assist with designing the best structure for a hybrid system satisfying the constraints. In hybrid energy system sources such as photovoltaic (PV, wind, diesel, and energy storage devices are connected as an electrical load supply. Because the power produced by PV and wind turbine sources is dependent on the variation of the resources (sun and wind and the load demand fluctuates, such a hybrid system must be able to satisfy the load requirements at any time and store the excess energy for use in deficit conditions. Therefore, reliability and cost are the two main criteria when designing a stand-alone hybrid system. Moreover, the operation of a diesel generator is important to achieve greater reliability. In this paper, TAC, LPSP, and the fuel cost of the diesel generator are considered as the objective variables and a hybrid teaching–learning-based optimization algorithm is proposed and used to choose the best structure of a stand-alone hybrid PV/wind/diesel/battery system. Simulation results from MATLAB support the effectiveness of the proposed method and confirm that it is more efficient than conventional methods.

  4. Reliability evaluation of emergency AC power systems based on operating experience at U.S. nuclear power plants

    International Nuclear Information System (INIS)

    The reliability of emergency AC power Systems has been under study at the U.S. Nuclear Regulatory Commission and by its contractors for several years. This paper provides the results of work recently performed to evaluate past U.S. nuclear power plant emergency AC power System reliability performance using system level data. Operating experience involving multiple diesel generator failures, unavailabilities, and simultaneous occurrences of failures and out of service diesel generators were used to evaluate reliability performance at individual nuclear power plants covering a 9 year period from 1976 through 1984. The number and nature of failures and distributions of reliability evaluation results are provided. The results show that plant specific performance varied considerably during the period with a large number achieving high reliability performance and a smaller number accounting for lower levels of reliability performance. (author)

  5. Improved Power Flow Algorithm for VSC-HVDC System Based on High-Order Newton-Type Method

    Directory of Open Access Journals (Sweden)

    Yanfang Wei

    2013-01-01

    Full Text Available Voltage source converter (VSC based high-voltage direct-current (HVDC system is a new transmission technique, which has the most promising applications in the fields of power systems and power electronics. Considering the importance of power flow analysis of the VSC-HVDC system for its utilization and exploitation, the improved power flow algorithms for VSC-HVDC system based on third-order and sixth-order Newton-type method are presented. The steady power model of VSC-HVDC system is introduced firstly. Then the derivation solving formats of multivariable matrix for third-order and sixth-order Newton-type power flow method of VSC-HVDC system are given. The formats have the feature of third-order and sixth-order convergence based on Newton method. Further, based on the automatic differentiation technology and third-order Newton method, a new improved algorithm is given, which will help in improving the program development, computation efficiency, maintainability, and flexibility of the power flow. Simulations of AC/DC power systems in two-terminal, multi-terminal, and multi-infeed DC with VSC-HVDC are carried out for the modified IEEE bus systems, which show the effectiveness and practicality of the presented algorithms for VSC-HVDC system.

  6. Automatic generation control application with craziness based particle swarm optimization in a thermal power system

    Energy Technology Data Exchange (ETDEWEB)

    Gozde, Haluk; Taplamacioglu, M. Cengiz [Gazi University, Faculty of Engineering, Department of Electrical and Electronics Engineering, 06750 Maltepe, Ankara (Turkey)

    2011-01-15

    In this study, a novel gain scheduling Proportional-plus-Integral (PI) control strategy is suggested for automatic generation control (AGC) of the two area thermal power system with governor dead-band nonlinearity. In this strategy, the control is evaluated as an optimization problem, and two different cost functions with tuned weight coefficients are derived in order to increase the performance of convergence to the global optima. One of the cost functions is derived through the frequency deviations of the control areas and tie-line power changes. On the other hand, the other one includes the rate of changes which can be variable depends on the time in these deviations. These weight coefficients of the cost functions are also optimized as the controller gains have been done. The craziness based particle swarm optimization (CRAZYPSO) algorithm is preferred to optimize the parameters, because of convergence superiority. At the end of the study, the performance of the control system is compared with the performance which is obtained with classical integral of the squared error (ISE) and the integral of time weighted squared error (ITSE) cost functions through transient response analysis method. The results show that the obtained optimal PI-controller improves the dynamic performance of the power system as expected as mentioned in literature. (author)

  7. Power system transient stability simulation based on module bi-directional iteration

    Institute of Scientific and Technical Information of China (English)

    FANG; Dazhong; YANG; Xiaodong

    2005-01-01

    A new simultaneous solution method using module bi-directional iteration is proposed for power system transient stability simulation. In this method, power network is partitioned into a tree hierarchy; computation modules are established for decomposed power networks and various power system components respectively. Through representing every computation module by a computation node, a computation tree is constructed by connecting the nodes together according to their electrical relations in power systems. A tree-traversing procedure called forward reduction and backward evaluation is performed to calculate correction factors of the variables in Newton iterations. This high-efficiency simulation method is feasible to be applied in parallel computation for large interconnected systems. Simulation tests are conducted on the New England 10-generator test power system and the North China-Northeast interconnected system, and the results are compared with those of the commercial software BPA to validate the effectiveness and correctness of this method.

  8. UNIFIED MODELS OF ELEMENTS OF POWER SUPPLY SYSTEMS BASED ON EQUATIONS IN PHASE COORDINATES

    Directory of Open Access Journals (Sweden)

    Yu.N. Vepryk

    2015-12-01

    Full Text Available Purpose. The models of electrical machines in the phase coordinates, the universal algorithm for the simulation of separate elements in a d-q coordinates system and in a phase-coordinates system are proposed. Methodology. Computer methods of investigation of transients in electrical systems are based on a compilation of systems of differential equations and their numerical integration solution methods. To solve differential equations an implicit method of numerical integration was chosen. Because it provides to complete structural simulation possibility: firstly developing models of separate elements and then forming a model of the complex system. For the mathematical simulation of electromagnetic transients in the elements of the electrical systems has been accepted the implicit Euler-Cauchy method, because it provides a higher precision and stability of the computing processes. Results. In developing the model elements identified two groups of elements: - Static elements and electrical machines in the d-q coordinates; - Rotating electrical machines in phase coordinates. As an example, the paper provides a model of synchronous and asynchronous electric machines in the d-q coordinates system and the phase coordinate system. The generalization algorithm and the unified notation form of equations of elements of an electrical system are obtained. It provides the possibility of using structural methods to develop a mathematical model of power systems under transient conditions. Practical value. In addition, the using of a computer model allows to implement multivariant calculations for research and study of factors affecting the quantitative characteristics of the transients.

  9. An SOS2-based moving trains,fixed nodes, railway power system simulator

    OpenAIRE

    Abrahamsson, Lars; Söder, Lennart

    2012-01-01

    This paper presents and proposes an optimization model for railway power supply system simulations. It includes detailed power systems modeling train movements in discretized time considering running resistance and other mechanical constraints, and the voltage-drop-induced reduction of possible train tractive forces. The model has a xed number of stationary power system nodes. The proposed model uses SOS2 (special ordered sets of type 2) variables to distribute the train loads to the two most...

  10. 76 FR 2368 - Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2011-01-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based... supplemental notice in the above-referenced proceeding of Balance Power Systems, LLC's application for...

  11. Development of Power Controller System based on Model Reference Adaptive Control for a Nuclear Reactor

    International Nuclear Information System (INIS)

    The Reactor TRIGA PUSPATI (RTP)-type TRIGA Mark II was installed in the year 1982. The Power Controller System (PCS) or Automated Power Controller System (APCS) is very important for reactor operation and safety reasons. It is a function of controlled reactivity and reactor power. The existing power controller system is under development and due to slow response, low accuracy and low stability on reactor power control affecting the reactor safety. The nuclear reactor is a nonlinear system in nature, and it is power increases continuously with time. The reactor parameters vary as a function of power, fuel burnup and control rod worth. The output power value given by the power control system is not exactly as real value of reactor power. Therefore, controller system design is very important, an adaptive controller seems to be inevitable. The method chooses is a linear controller by using feedback linearization, for example Model Reference Adaptive Control. The developed APCS for RTP will be design by using Model Reference Adaptive Control (MRAC). The structured of RTP model to produce the dynamic behaviour of RTP on entire operating power range from 0 to 1MWatt. The dynamic behavior of RTP model is produced by coupling of neutronic and thermal-hydraulics. It will be developed by using software MATLAB/Simulink and hardware module card to handle analog input signal. A new algorithm for APCS is developed to control the movement of control rods with uniformity and orderly for RTP. Before APCS test to real plant, simulation results shall be obtained from RTP model on reactor power, reactivity, period, control rod positions, fuel and coolant temperatures. Those data are comparable with the real data for validation. After completing the RTP model, APCS will be tested to real plant on power control system performance by using real signal from RTP including fail-safe operation, system reliable, fast response, stability and accuracy. The new algorithm shall be a satisfied

  12. Experience teaching CD-ROM-based course on CANDU nuclear-power-plant systems and operation

    International Nuclear Information System (INIS)

    This paper presents personal experience garnered from teaching a CD-ROM-based course on CANDU Power-Plant Systems and Operation. This course was originally developed by Prof. G.T. Bereznai as research in distance-learning techniques when he was directing the Thai-Canadian Human Resources Development Project at Chulalongkorn University in Bangkok. The course has been offered in a number of universities, including McMaster University and the University of Ontario Institute of Technology. All the course material, including lectures, assignments, and a simulator, is provided on a CD-ROM. Lectures include a spoken soundtrack covering the material. The class often includes both undergraduate and graduate students. I found that most students appreciate having the material on electronic format, which they can view and review at will and on their own time. Students find this course quite intensive - it covers all major systems in the CANDU reactor and power plant in detail. A very important component of the course is the simulator, which teaches students how systems operate in normal operation, in power manoeuvres, and during process-system malfunctions. Effort in absorbing the material and performing assignments can often exceed 10 hours per week. Some of the simulator assignments involve tricky manoeuvres, requiring several tries to achieve the expected result. Some assignments may take several hours, especially if the manoeuvres requiring repetition take 30 minutes or more in real time. I found that some instruction in the basic theory of reactor physics and systems is appreciated by students. A few possible enhancements to the simulator model were identified. Graduate students taking the course are required to do an additional project; I assigned an investigation of the effects of xenon-concentration changes during 1 week of load cycling. In summary, this course provides to students the opportunity to learn a great deal about the workings of CANDU-plant systems. (author)

  13. Electric power systems

    CERN Document Server

    Weedy, B M; Jenkins, N; Ekanayake, J B; Strbac, G

    2012-01-01

    The definitive textbook for Power Systems students, providing a grounding in essential power system theory while also focusing on practical power engineering applications. Electric Power Systems has been an essential book in power systems engineering for over thirty years. Bringing the content firmly up-to-date whilst still retaining the flavour of Weedy's extremely popular original, this Fifth Edition has been revised by experts Nick Jenkins, Janaka Ekanayake and Goran Strbac. This wide-ranging text still covers all of the fundamental power systems subjects but is now e

  14. Minimum cost solution of wind–photovoltaic based stand-alone power systems for remote consumers

    International Nuclear Information System (INIS)

    Renewable energy sources (RES) based stand-alone systems employing either wind or solar power and energy storage comprise a reliable energy alternative, on top of conventional diesel-electric generator sets, commonly used by remote consumers. However, such systems usually imply the need for oversizing and considerable energy storage requirements leading to relatively high costs. On the other hand, hybrid configurations that may exploit both wind and solar potential of a given area may considerably reduce energy storage capacity and improve the economic performance of the system. In this context, an integrated techno-economic methodology for the evaluation of hybrid wind–photovoltaic stand-alone power systems is currently developed, aiming at the designation of optimum configurations for a typical remote consumer, using economic performance criteria. For the problem investigation, the developed evaluation model is applied to four representative areas of the Greek territory with different wind potential characteristics in order to obtain optimum configurations on the basis of minimum initial investment, 10-year and 20-year total cost. According to the results obtained, the proposed solution is favorably compared with all other stand-alone energy alternatives, reflecting the ability of hybrid systems to adjust even in areas where the local RES potential is not necessarily of high quality. - Highlights: ► Wind- and PV-stand alone systems often imply use of extreme battery capacity. ► Hybrid wind–PV systems may reduce energy storage requirements and associated costs. ► An optimization methodology is developed, based on economic performance criteria. ► Methodology is applied to four Greek regions of different wind potential. ► Results obtained reflect the hybrid solution's advantages over other alternatives.

  15. Power system transient stability simulation under uncertainty based on Taylor model arithmetic

    Institute of Scientific and Technical Information of China (English)

    Shouxiang WANG; Zhijie ZHENG; Chengshan WANG

    2009-01-01

    The Taylor model arithmetic is introduced to deal with uncertainty. The uncertainty of model parameters is described by Taylor models and each variable in functions is replaced with the Taylor model (TM). Thus,time domain simulation under uncertainty is transformed to the integration of TM-based differential equations. In this paper, the Taylor series method is employed to compute differential equations; moreover, power system time domain simulation under uncertainty based on Taylor model method is presented. This method allows a rigorous estimation of the influence of either form of uncertainty and only needs one simulation. It is computationally fast compared with the Monte Carlo method, which is another technique for uncertainty analysis. The proposed method has been tested on the 39-bus New England system. The test results illustrate the effectiveness and practical value of the approach by comparing with the results of Monte Carlo simulation and traditional time domain simulation.

  16. A New Fractional-Order Based Intelligent Maximum Power Point Tracking Control Algorithm for Photovoltaic Power Systems

    Directory of Open Access Journals (Sweden)

    Kuo-Nan Yu

    2015-01-01

    Full Text Available This paper proposes a new type of variable fractional-order incremental conductance algorithm (VFOINC, combined with extenics variable step size (EVSS control into the maximum power point tracking (MPPT design for photovoltaic power systems. At the beginning of maximum power tracking, the fractional-order number α is selected as 1; the good transient tracking characteristic of traditional incremental conductance method is used. When the maximum power point is approached, the fractional-order number α is selected as variable fractional order; the curve profile of α in fractional order is used to approximate, so that the system has good tracking effect in transient and steady states. The experimental and simulation results show that, compared with traditional incremental conductance method (INC and fractional-order incremental conductance method (FOINC, this method has better MPPT effect.

  17. Mean value-based power allocation and ratio selection for MIMO cognitive radio systems

    KAUST Repository

    Tourki, Kamel

    2013-06-01

    In this paper, we consider a spectrum sharing cognitive radio system with ratio selection using a mean value-based power allocation strategy. We first provide the exact statistics in terms of probability density function and cumulative density function of the secondary channel gain as well as of the interference channel gain. These statistics are then used to derive exact closed form expression of the secondary outage probability. Furthermore, asymptotical analysis is derived and generalized diversity gain is deduced. We validate our analysis with simulation results in a Rayleigh fading environment. © 2013 IEEE.

  18. Control Architecture for Paralleled Current-Source-Inverter (CSI) based Uninterruptible Power Systems (UPS)

    DEFF Research Database (Denmark)

    Wei, Baoze; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.;

    2016-01-01

    This paper describes a theoretical and simulation study on a control strategy for the parallel operation of threephase current source inverters (CSI), to be applied to uninterruptible power systems (UPS). A circulating current suppression strategy for parallel CSIs is proposed in this paper based......, and the virtual impedance is used to fix the output impedance of the inverters. In addition, a secondary control is used in order to recover the voltage deviation caused by the virtual impedance. and the auxiliary current control loop is added to acquire a better average current sharing performance among parallel...

  19. WAMS-based monitoring and control of Hopf bifurcations in multi-machine power systems

    Institute of Scientific and Technical Information of China (English)

    Shao-bu WANG; Quan-yuan JIANG; Yi-jia CAO

    2008-01-01

    A method is proposed to monitor and control Hopf bifurcations in multi-machine power systems using the information from wide area measurement systems (WAMSs). The power method (PM) is adopted to compute the pair of conjugate eigenvalues with the algebraically largest real part and the corresponding eigenvectors of the Jacobian matrix of a power system. The distance between the current equilibrium point and the Hopf bifurcation set can be monitored dynamically by computing the pair of conjugate eigenvalues. When the current equilibrium point is close to the Hopf bifurcation set, the approximate normal vector to the Hopf bifurcation set is computed and used as a direction to regulate control parameters to avoid a Hopf bifurcation in the power system described by differential algebraic equations (DAEs). The validity of the proposed method is demonstrated by regulating the reactive power loads in a 14-bus power system.

  20. An active damper for stabilizing power electronics-based AC systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco;

    2013-01-01

    The mutual interactions between the parallel grid-connected converters coupled through the grid impedance tend to result in a number of stability and power quality challenges. To address them, this paper proposes an active damper concept based on a low-power, high-bandwidth power converter. The b...

  1. Design of monitoring and control system of digital power supply for HIMM based on microcontroller

    International Nuclear Information System (INIS)

    The touch screen control system is under development in Heavy Ion Medical Machine (HIMM) project. In this paper, the touch screen control system is studied in detail, which is driven by PIC24 microcontroller. According to the internal protocol of power system , control of power switch , waveform and state display, parameter setting are all implemented in this control system. The communication among microcontroller, FPGA board for power supply and state board is normal and stable during the test. Compared to analog switch control system, the local control system for HIMM is much more convenient and aesthetic, additionally the control accuracy is even higher. (authors)

  2. An FPGA Based Controller for a SOFC DC-DC Power System

    Directory of Open Access Journals (Sweden)

    Kanhu Charan Bhuyan

    2013-01-01

    Full Text Available Fuel cells are an attractive option for alternative power and of use in a variety of applications. This paper proposes a state space model for the solid oxide fuel cell (SOFC based power system that comprises fuel cell, DC-DC buck converter, and load. In this investigation we have taken up a case study for SOFC feeding a DC load where a DC-DC buck converter acts as the interface between the load and the source. A proportional-integral (PI controller is used in conjunction with pulse width modulation (PWM that computes the pulse width and switches the MOSFET at the right instant so that the desired voltage is obtained. The proposed model is validated through extensive simulation using MATLAB/SIMULINK. Controller for the fuel cell power system (FCPS is prototyped using XC3S500E development board containing a SPARTAN 3E Xilinx FPGA that simplifies the entire control circuit besides providing additional flexibility for further improvement. The results clearly indicate improved performance and validate our proposed model.

  3. PPNOCS: Performance and Power Network on Chip Simulator based on SystemC

    Directory of Open Access Journals (Sweden)

    El Sayed M. Saad

    2011-11-01

    Full Text Available As technology moves towards multi-core system-on-chips (SoCs, networks-on-chip (NoCs are emerging as the scalable fabric for interconnecting the cores. Network-on-Chip architectures have a wide variety of parameters that can be adapted to the designers requirements. This paper proposes a performance and power network on chip simulator (PPNOCS based on SystemC to explore the impact of various architectural level parameters of the on-chip interconnection network elements on its performance and power. PPNOCS supports an arbitrary size of mesh and torus topology, adopts five classic routing algorithms and seven synthetic traffic patterns. Developers also can develop and verify their own network design by modifying the corresponding modules. Experiments of using this simulator are carried out to study the power, latency and throughput of a 4x4 multi-core mesh network topology. Results show that PPNOCS provides a fast and convenient platform for researching and verification of NoC architectures and routing algorithms.

  4. Cost-optimal power system extension under flow-based market coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hagspiel, Simeon; Jaegemann, Cosima; Lindenberger, Dietmar [Koeln Univ. (Germany). Energiewirtschaftliches Inst.; Brown, Tom; Cherevatskiy, Stanislav; Troester, Eckehard [Energynautics GmbH, Langen (Germany)

    2013-05-15

    Electricity market models, implemented as dynamic programming problems, have been applied widely to identify possible pathways towards a cost-optimal and low carbon electricity system. However, the joint optimization of generation and transmission remains challenging, mainly due to the fact that different characteristics and rules apply to commercial and physical exchanges of electricity in meshed networks. This paper presents a methodology that allows to optimize power generation and transmission infrastructures jointly through an iterative approach based on power transfer distribution factors (PTDFs). As PTDFs are linear representations of the physical load flow equations, they can be implemented in a linear programming environment suitable for large scale problems. The algorithm iteratively updates PTDFs when grid infrastructures are modified due to cost-optimal extension and thus yields an optimal solution with a consistent representation of physical load flows. The method is first demonstrated on a simplified three-node model where it is found to be robust and convergent. It is then applied to the European power system in order to find its cost-optimal development under the prescription of strongly decreasing CO{sub 2} emissions until 2050.

  5. On the perspectives of wide-band gap power devices in electronic-based power conversion for renewable systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos Araujo, Samuel

    2013-10-01

    The high breakdown field from WBG materials allows the construction of unipolar devices with very low specific chip resistance mainly characterized by very low conduction and switching losses, even at high blocking voltages. Suitable concepts for SiC and GaN range from traditional FET structures driven by a MOS interface or a PN-Junction, bipolar devices and even high-electron mobility transistors (HEMT). A detailed revision of the literature will be performed in this work with the objective of providing a broad overview of possible approaches, along with inherent advantages and limitations. In addition to this, a benchmarking of several SiC-based devices technologies rated for 1200 V and 1700 V will be performed against their state-of-the-art Silicon-counterparts. Concerning the application of wide band gap devices in renewable energy systems, a significant cost reduction potential can be obtained due to smaller expenditure with magnetic filters and cooling, alongside higher efficiency levels. These aspects will be discussed in details in order to identify constraints and bottlenecks at application level with special focus on photovoltaic and wind power systems.

  6. Integrated method for constructing knowledge base system for proactive trouble prevention of nuclear power plant

    International Nuclear Information System (INIS)

    Integrated method for constructing knowledge base (KB) system for proactive trouble prevention of complex machine system such as nuclear power plant has been studied in this paper. The new ideas employed in this study are: (1) Structuralizing trouble KB for trouble prediction and prevention, (2) Realizing such KB by using web database, (3) Modeling plant system by the combination of solid matters and non-solid matters, (4) Modeling solid matters as object-oriented KB with the combination of structural components and electrical circuits, usage and environmental conditions and knowledge on troubles, and (5) Modeling non-solid matters by a revised Multilevel Flow Model (MFM). The framework is proposed on how to systemize those five different ideas on the basis of graphical modeling method by the revised MFM. A preliminary study is also conducted on applying the proposed method to a fast reactor prototype 'Monju', in order to reduce problems to be improved for the usage of revised MFM for real scale application for nuclear power plant. (author)

  7. Advanced Adaptive Particle Swarm Optimization based SVC Controller for Power System Stability

    Directory of Open Access Journals (Sweden)

    Poonam Singhal

    2014-12-01

    Full Text Available The interconnected systems is continually increasing in size and extending over whole geographical regions, it is becoming increasingly more difficult to maintain synchronism between various parts of the power system. This paper work presents an advanced adaptive Particle swarm optimization technique to optimize the SVC controller parameters for enhancement of the steady state stability & overcoming the premature convergence & stagnation problems as in basic PSO algorithm & Particle swarm optimization with shrinkage factor & inertia weight approach (PSO-SFIWA. In this paper SMIB system along with PID damped SVC controller is considered for study. The generator speed deviation is used as an auxiliary signal to SVC, to generate the desired damping. This controller improves the dynamic performance of power system by reducing the steady-state error. The controller parameters are optimized using basic PSO, PSO-SFIWA & Advanced Adaptive PSO. Computational results show that Advanced Adaptive based SVC controller is able to find better quality solution as compare to conventional PSO & PSO-SFIWA Techniques.

  8. Mitigation Emission Strategy Based on Resonances from a Power Inverter System in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Li Zhai

    2016-05-01

    Full Text Available Large dv/dt and di/dt outputs of power devices in the DC-fed motor power inverter can generate conducted and/or radiated emissions through parasitics that interfere with low voltage electric systems in electric vehicles (EVs and nearby vehicles. The electromagnetic interference (EMI filters, ferrite chokes, and shielding added in the product process based on the “black box” approach can reduce the emission levels in a specific frequency range. However, these countermeasures may also introduce an unexpected increase in EMI noises in other frequency ranges due to added capacitances and inductances in filters resonating with elements of the power inverter, and even increase the weight and dimension of the power inverter system in EVs with limited space. In order to predict the interaction between the mitigation techniques and power inverter geometry, an accurate model of the system is needed. A power inverter system was modeled based on series of two-port network measurements to study the impact of EMI generated by power devices on radiated emission of AC cables. Parallel resonances within the circuit can cause peaks in the S21 (transmission coefficient between the phase-node-to-chassis voltage and the center-conductor-to-shield voltage of the AC cable connecting to the motor and Z11 (input impedance at Port 1 between the Insulated gate bipolar transistor (IGBT phase node and chassis at those resonance frequencies and result in enlarged noise voltage peaks at Port 1. The magnitude of S21 between two ports was reduced to decrease the amount of energy coupled from the noise source between the phase node and chassis to the end of the AC cable by lowering the corresponding quality factor. The equivalent circuits were built by analyzing current-following paths at three critical resonance frequencies. Interference voltage peaks can be suppressed by mitigating the resonances. The capacitances and inductances generating the parallel resonances and

  9. Model based fleet optimisation and master control of a power production system

    International Nuclear Information System (INIS)

    This paper discussed an optimization concept for power plants operated by the Danish power company Elsam. The power company operates a distributed power production system with fossil fuel thermal plants, biomass-fired thermal plants, waste incineration plants, on- and offshore wind power, and district heating storage units. Power and regulation power are traded on an hourly basis, while trading of district heating resources is conducted using bilateral contracts. System and plant level case studies on optimization and control were presented. A system control level was developed to ensure compliance with power market requirements. Dynamic constraints were posed by environmental regulations, grid capabilities, and fuel and district heating contracts. System components included a short-term load scheduler; a power controller; a frequency control scheduler; a marginal cost calculator; and a master control. The scheduler consisted of an optimization algorithm and a set of steady-state models designed to minimize fuel, load, and maintenance costs. Quadratic programming and mixed integer programming methods were used to minimize deviations between the total electrical power production reference value and actual power production values. The study showed that control levels can be optimized using advanced modelling and control methods. However, integration and coordination between the various levels is needed to obtain improved performance. It was concluded that a bottom-up approach starting at the lowest possible level can ensure the performance of an optimization scheme. 6 refs., 9 figs

  10. Intelligent Control and Protection Methods for Modern Power Systems Based on WAMS

    DEFF Research Database (Denmark)

    Liu, Leo

    of a number of contingencies in various operating conditions. By statistical analysis, vulnerable areas in terms of transient stability are identified. Furthermore, the result of CCT computation in different typical scenarios can evaluate the impact of wind power on power system transient stability. Other...... condition. Among pattern recognition techniques, decision trees (DT) using the algorithm of classification and regression trees (CART) is applied in DSA of western Danish power system. It not only provides the results of security assessment but also reveal the principles learned by DTs for security......Continuously growing demand for electricity, driven by deregulated power markets, has forced power systems to operate closer to their security operation limits. Meanwhile, the increasing penetration of large scale renewable energy may impact the operation of power systems by bringing more...

  11. Automation infrastructure and operation control strategy in a stand-alone power system based on renewable energy sources

    Science.gov (United States)

    Ziogou, Chrysovalantou; Ipsakis, Dimitris; Elmasides, Costas; Stergiopoulos, Fotis; Papadopoulou, Simira; Seferlis, Panos; Voutetakis, Spyros

    The design of the automation system and the implemented operation control strategy in a stand-alone power system in Greece are fully analyzed in the present study. A photovoltaic array and three wind generators serve as the system main power sources and meet a predefined load demand. A lead-acid accumulator is used to compensate the inherent power fluctuations (excess or shortage) and to regulate the overall system operation, based on a developed power management strategy. Hydrogen is produced by using system excess power in a proton exchange membrane (PEM) electrolyzer and is further stored in pressurized cylinders for subsequent use in a PEM fuel cell in cases of power shortage. A diesel generator complements the integrated system and is employed only in emergency cases, such as subsystems failure. The performance of the automatic control system is evaluated through the real-time operation of the power system where data from the various subsystems are recorded and analyzed using a supervised data acquisition unit. Various network protocols were used to integrate the system devices into one central control system managing in this way to compensate for the differences between chemical and electrical subunits. One of the main advantages is the ability of process monitoring from distance where users can perform changes to system principal variables. Furthermore, the performance of the implemented power management strategy is evaluated through simulated scenarios by including a case study analysis on system abilities to meet higher than expected electrical load demands.

  12. Energy management systems on board of electric vehicles, based on power electronics

    Energy Technology Data Exchange (ETDEWEB)

    Guidi, Giuseppe

    2009-03-15

    storage components and of the electrical drive train in general, rather than being a mere component-level optimization of well established topologies. A novel converter topology is proposed for hybridization of the energy source with a supercapacitor-based power buffer being used to assist the main traction battery. From the functional point of view, the topology implements a bidirectional DC/DC converter. Making use of the fact that the battery terminal voltage is close to constant, an arrangement for the supercapacitors is devised allowing for bidirectional power flow by using power electronics devices of lower ratings than the ones needed in conventional DC/DC converters. At the same time, much smaller magnetic components are needed. Theoretical analysis of the operation of the proposed converter is given, allowing for optimized design. A full-scale experimental prototype rated at 30 kW, intended for use in a pure EV, has been built and tested. Results validate the theory and show that no particular impediment exist to the deployment of the concept in practical applications. Another concept introduced in the thesis is an architecture where the traction inverter is embedded in the energy storage device. The latter is constituted by several modules, as in the case of modern Li-ion battery systems, and each module is equipped with a local power electronics interface, making it functionally equivalent to a controllable voltage source. The result is a modular, distributed system that can be engineered to have very high reliability and also to exhibit self-healing properties. A prototype with a minimum number of modules has been built and tested. Results confirm the effectiveness of the system, and make it a good candidate for deployment in applications where reliability is the most important requirement. (Author). 107 refs., 93 figs., 16 tabs

  13. Decision Envelopment Analysis of space and terrestrially-based large scale commercial power systems for earth

    Science.gov (United States)

    Criswell, David R.; Thompson, Russell G.

    1992-08-01

    Decision Envelopment Analysis (DEA), the detailed quantitative comparison of alternative economic systems, is used to compare the technical efficiency of the large-scale power systems needed to meet the growing energy needs of terrestrial society. The Lunar Power System (LPS) captures sunlight on the moon, converts it to microwaves and beams the power to receivers on earth that output electricity. In terms of benefits versus costs, normalized to the range of 0 to 1, DEA reveals that LPS is at least ten times more efficient than conventional terrestrial solar-thermal and -photovoltaic, fossil, and nuclear systems. LPS is also environmentally benign compared to the conventional systems.

  14. Enhancement of Power System Dynamics Using TCSC Based Hybride Series Capacitive Compensation

    OpenAIRE

    Madupu Renuka*; Nomula Ganesh

    2014-01-01

    This paper demonstrate phase imbalanced series capacitive compensation to enhancing power system dynamics as it has the potential of damping power swing as well as subsynchronous resonance oscillations. In this paper, the effectiveness of a “hybrid” series capacitive compensation scheme in single line and double line to damping power system oscillations is computed. A hybrid concept is a series capacitive compensation scheme, in one case two phases are compensated by fixed ser...

  15. Confidentiality-preserving Obfuscation for Cloud-based Power System Contingency Analysis

    OpenAIRE

    Vuković, Ognjen; Dán, György; Bobba, Rakesh

    2013-01-01

    Power system operators are looking to adopt and migrate to cloud technologies and third-party cloud services for customer facing and enterprise IT applications. Security and reliability are major barriers for adopting cloud technologies and services for power system operational applications. In this work we focus on the use of cloud computing for Contingency Analysis and propose an approach to obfuscate information regarding power flows and the presence of a contingency violation while allowi...

  16. Static Var Compensator based on Fuzzy Logic Control for Damping Power System Oscillation

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2011-01-01

    Full Text Available Problem statement: The disturbance in power system is unavoidable situation. It causes in power system oscillation. Approach: This study applied the Static Var Compensator (SVC to damp power system oscillation. The fuzzy logic control is applied to determine the control strategy of SVC. The simulation results are tested on a Single Machine Infinite bus. The proposed method is equipped in sample system with disturbance. The generator rotor angle curve of the system without and with a SVC is plotted and compared. Results: It was found that the system without a SVC has high variation whereas that of the system with a SVC has much smaller variation. Conclusion: From the simulation results, the SVC can damp power system oscillation.

  17. Design and optimization of a 3-coil resonance-based wireless power transfer system for biomedical implants

    KAUST Repository

    Yi, Ying

    2014-09-01

    This paper presents a resonance-based wireless power transfer system using a single layer of inductor coil windings, in a pancake configuration, in order to obtain a compact system for implantable electronic applications. We theoretically analyzed the system and characterized it by measuring its inductance, self-resonant frequency, and quality factor Q. In our resonance-based wireless power transfer prototype, we proposed a 3-coil system, using two 15-mm radius implantable coils, with a resonance frequency of 6.76MHz. This system can effectively transfer power for a distance of up to 50mm. Moreover, our proposed 3-coil system can achieve a high Q-factor and has a comparable power transfer efficiency (PTE) to previously reported works about 3-coil and 4-coil systems. The experimental PTE can achieve 82.4% at a separation distance of 20mm and more than 10% PTE at a distance of 40mm.

  18. Power system relaying

    CERN Document Server

    Horowitz, Stanley H; Niemira, James K

    2013-01-01

    The previous three editions of Power System Relaying offer comprehensive and accessible coverage of the theory and fundamentals of relaying and have been widely adopted on university and industry courses worldwide. With the third edition, the authors have added new and detailed descriptions of power system phenomena such as stability, system-wide protection concepts and discussion of historic outages. Power System Relaying, 4th Edition continues its role as an outstanding textbook on power system protection for senior and graduate students in the field of electric power engineering and a refer

  19. A New-Trend Model-Based to Solve the Peak Power Problems in OFDM Systems

    Directory of Open Access Journals (Sweden)

    Ashraf A. Eltholth

    2008-01-01

    Full Text Available The high peak to average power ration (PAR levels of orthogonal frequency division multiplexing (OFDM signals attract the attention of many researchers during the past decade. Existing approaches that attack this PAR issue are abundant, but no systematic framework or comparison between them exists to date. They sometimes even differ in the problem definition itself and consequently in the basic approach to follow. In this paper, we propose a new trend in mitigating the peak power problem in OFDM system based on modeling the effects of clipping and amplifier nonlinearities in an OFDM system. We showed that the distortion due to these effects is highly related to the dynamic range itself rather than the clipping level or the saturation level of the nonlinear amplifier, and thus we propose two criteria to reduce the dynamic range of the OFDM, namely, the use of MSK modulation and the use of Hadamard transform. Computer simulations of the OFDM system using Matlab are completely matched with the deduced model in terms of OFDM signal quality metrics such as BER, ACPR, and EVM. Also simulation results show that even the reduction of PAR using the two proposed criteria is not significat, and the reduction in the amount of distortion due to HPA is truley delightful.

  20. Shipboard electrical power systems

    CERN Document Server

    Patel, Mukund R

    2011-01-01

    Shipboard Electrical Power Systems addresses new developments in this growing field. Focused on the trend toward electrification to power commercial shipping, naval, and passenger vessels, this book helps new or experienced engineers master cutting-edge methods for power system design, control, protection, and economic use of power. Provides Basic Transferable Skills for Managing Electrical Power on Ships or on LandThis groundbreaking book is the first volume of its kind to illustrate optimization of all aspects of shipboard electrical power systems. Applying author Mukund Patel's rare combina

  1. Adaptive Neurofuzzy Inference System-Based Pollution Severity Prediction of Polymeric Insulators in Power Transmission Lines

    Directory of Open Access Journals (Sweden)

    C. Muniraj

    2011-01-01

    Full Text Available This paper presents the prediction of pollution severity of the polymeric insulators used in power transmission lines using adaptive neurofuzzy inference system (ANFIS model. In this work, laboratory-based pollution performance tests were carried out on 11 kV silicone rubber polymeric insulator under AC voltage at different pollution levels with sodium chloride as a contaminant. Leakage current was measured during the laboratory tests. Time domain and frequency domain characteristics of leakage current, such as mean value, maximum value, standard deviation, and total harmonics distortion (THD, have been extracted, which jointly describe the pollution severity of the polymeric insulator surface. Leakage current characteristics are used as the inputs of ANFIS model. The pollution severity index “equivalent salt deposit density” (ESDD is used as the output of the proposed model. Results of the research can give sufficient prewarning time before pollution flashover and help in the condition based maintenance (CBM chart preparation.

  2. Fault diagnosis for power system transmission line based on PCA and SVMs

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yuanjun; Li, Kang; Liu, Xueqin [Queen' s Univ., Belfast (United Kingdom). School of Electronics, Electrical Engineering and Computer Science

    2013-07-01

    This paper presents the application of a fault detection method based on the principal component analysis (PCA) and support vector machine (SVM) for the detection and classification of faults in power system transmission lines. Consider that the data may be huge with a number of strongly correlated variables, method which incorporates both the principal component analysis (PCA) and support vector machine (SVM) is proposed. This algorithm has two stages. The first stage involves the use of the PCA to reduce the dimensionality as well as to find violating point of the signals according to the confidential limit. The features of each fault extracted from the data are used in the second stage to construct SVM networks. The second stage is to use pattern recognition method to distinguish the phase of the faulty situation. The proposed scheme is able to solve the problems encountered in traditional magnitude and frequency based methods. The benefits of this improvement are demonstrated.

  3. Comparative study of alternative ORC-based combined power systems to exploit high temperature waste heat

    International Nuclear Information System (INIS)

    Highlights: • Three ORC-based combined systems for ICE exhaust waste heat recovery are studied. • A parametric investigation is conducted under several typical engine conditions. • Performance is evaluated considering six thermodynamic, techno-economic indexes. • DORC distinguishes among other solutions for its highest energy recovery capacity. • TEG–ORC system becomes attractive when exhaust temperature is relatively low. - Abstract: In this paper, various combined power systems which regard organic Rankine cycle (ORC) as bottoming cycle to recover engine’s high temperature exhaust heat are proposed. The topping recovery cycle includes steam Rankine cycle (RC), Brayton cycle (BC) and thermoelectric generator (TEG). Comprehensive evaluations are conducted under five typical engine conditions, ranging from high load to low load, and system performance is assessed in terms of many thermodynamic indexes, such as net output power, thermal efficiency, recovery efficiency and exergy efficiency. Besides that, the irreversibility of each component is also discussed in detail. R123, R245fa and R600a for ORC system are considered to analyze the influence of working fluids. Considering the system techno-economy, the turbine size parameter (SP) and heat transfer capacity (UA) are chosen as key indicators. The results show that compared with the other two investigated approaches, dual-loop ORC (DORC) possesses the highest energy exploitation capacity under the whole operating region, with a 5.57% increase of fuel economy under the rated condition, but its values of SP and UA are large as well. TEG–ORC becomes appealing while under the relatively low load

  4. Investigations on an advanced power system based on a high temperature polymer electrolyte membrane fuel cell and an organic Rankine cycle for heating and power production

    International Nuclear Information System (INIS)

    Energy systems based on fuel cells technology can have a strategic role in the range of small-size power generation for the sustainable energy development. In order to enhance their performance, it is possible to recover the “waste heat” from the fuel cells, for producing or thermal power (cogeneration systems) or further electric power by means of a bottoming power cycle (combined systems). In this work an advanced system based on the integration between a HT-PEMFC (high temperature polymer electrolyte membrane fuel cell) power unit and an ORC (organic Rankine cycle) plant, has been proposed and analysed as suitable energy power plant for supplying electric and thermal energies to a stand-alone residential utility. The system can operate both as cogeneration system, in which the electric and thermal loads are satisfied by the HT-PEMFC power unit and as electric generation system, in which the low temperature heat recovered from the fuel cells is used as energy source in the ORC plant for increasing the electric power production. A numerical model, able to characterize the behavior and to predict the performance of the HT-PEMFC/ORC system under different working conditions, has been developed by using the AspenPlus™ code. - Highlights: • The advanced plant can operate both as CHP system and as electric generation system. • The performance prediction of the integrated system is carried out by numerical modeling. • ORC thermodynamic optimization is carried out by a sensitivity analysis. • Thermal coupling between the HT-PEMC system and the ORC plant is analyzed. • Results are very promising in the field of the distributed generation

  5. The design of monitoring communication system Based on Power line carrier

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>The design of the power line carrier communication system was introduced in this paper,DSP was adopted as the hardware platform to complete the core task.DSP sending terminal delivered the collecting data to the DSP receiving terminal through the power line carrier, and the DSP receiving terminal send the data to PC through a serial port.The design improved the power line carrier communication system and the data transmission became faster and more reliable.The experiment results showed that the PER of the receiving data is less than 0.4%, which satisfied the power line carrier communication requirement Our design is feasible and effective.

  6. Computationally Efficient Power Allocation Algorithm in Multicarrier-Based Cognitive Radio Networks: OFDM and FBMC Systems

    Directory of Open Access Journals (Sweden)

    Shaat Musbah

    2010-01-01

    Full Text Available Cognitive Radio (CR systems have been proposed to increase the spectrum utilization by opportunistically access the unused spectrum. Multicarrier communication systems are promising candidates for CR systems. Due to its high spectral efficiency, filter bank multicarrier (FBMC can be considered as an alternative to conventional orthogonal frequency division multiplexing (OFDM for transmission over the CR networks. This paper addresses the problem of resource allocation in multicarrier-based CR networks. The objective is to maximize the downlink capacity of the network under both total power and interference introduced to the primary users (PUs constraints. The optimal solution has high computational complexity which makes it unsuitable for practical applications and hence a low complexity suboptimal solution is proposed. The proposed algorithm utilizes the spectrum holes in PUs bands as well as active PU bands. The performance of the proposed algorithm is investigated for OFDM and FBMC based CR systems. Simulation results illustrate that the proposed resource allocation algorithm with low computational complexity achieves near optimal performance and proves the efficiency of using FBMC in CR context.

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

    OpenAIRE

    Bin Zhao; Hui Li; Mingyu Wang; Yaojun Chen; Shengquan Liu; Dong Yang; Chao Yang; Yaogang Hu; Zhe Chen

    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 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 spe...

  8. Steady Fault Characteristic Analysis of a Missile Power System Based on a Differential Evolution Algorithm

    Institute of Scientific and Technical Information of China (English)

    XU Zhi-gao; GUAN Zheng-xi; MA Jing

    2005-01-01

    The differential evolution (DE) algorithm is applied to solving the models' equations of a whole missile power system, and the steady fault characteristics of the whole system are analyzed. The DE algorithm is robust, requires few control variables, is easy to use and lends itself very well to parallel computation. Calculation results indicate that the DE algorithm simulates faults of a missile power system very well.

  9. FIS/ANFIS Based Optimal Control for Maximum Power Extraction in Variable-speed Wind Energy Conversion System

    Science.gov (United States)

    Nadhir, Ahmad; Naba, Agus; Hiyama, Takashi

    An optimal control for maximizing extraction of power in variable-speed wind energy conversion system is presented. Intelligent gradient detection by fuzzy inference system (FIS) in maximum power point tracking control is proposed to achieve power curve operating near optimal point. Speed rotor reference can be adjusted by maximum power point tracking fuzzy controller (MPPTFC) such that the turbine operates around maximum power. Power curve model can be modelled by using adaptive neuro fuzzy inference system (ANFIS). It is required to simply well estimate just a few number of maximum power points corresponding to optimum generator rotor speed under varying wind speed, implying its training can be done with less effort. Using the trained fuzzy model, some estimated maximum power points as well as their corresponding generator rotor speed and wind speed are determined, from which a linear wind speed feedback controller (LWSFC) capable of producing optimum generator speed can be obtained. Applied to a squirrel-cage induction generator based wind energy conversion system, MPPTFC and LWSFC could maximize extraction of the wind energy, verified by a power coefficient stay at its maximum almost all the time and an actual power line close to a maximum power efficiency line reference.

  10. High-power chirped-pulse all-fiber amplification system based on large-mode-area fiber gratings

    OpenAIRE

    Broderick, N.G.R.; Richardson, D.J.; Taverner, D.; Caplen, J.E.; Dong, L.; Ibsen, M.

    1999-01-01

    The fabrication of large mode-area single mode fibres are crucial to developing high power all-fibre lasers and amplifiers. We report the amplification of picosecond pulses to microjoule energy levels and pulse peak powers in excess of 500kW in an all fiber Chirped Pulse Amplification (CPA) system based on novel large mode area fiber components.

  11. Performance analysis of fuzzy rule based classification system for transient identification in nuclear power plant

    International Nuclear Information System (INIS)

    Highlights: • An interpretable fuzzy system with acceptable accuracy can be used in nuclear power plant. • This system is worthy of being used as a redundant system for transient identification. • Deaerator level gives quicker response to fuzzy system, to classify transients in steam water system. • Increase in the number of input variables does not necessarily increase the efficiency of a fuzzy system. • Helps in operator guidance by reducing information overloading. - Abstract: Even though fuzzy rule based classification system (FRBCS) has been useful in event identification, it has led to strong clash in terms of better interpretability along with adequate percentage of accuracy. Basically for classification in nuclear power plant (NPP) which receives data within a cycle time of few milliseconds, either the accuracy or the interpretability of the FRBCS would get jeopardized. Online event identification of any abnormality or transient using FRBCS becomes really critical for the plant which has such a short cycle time. For such cases, the output from a FRBCS may not be conducive to classify the event every cycle. Thus, it is necessary to monitor the output of a classification system for certain amount of cycles till the static nature is attained. This gives a high level of confidence on the classifier output to be accurate. A FRBCS can produce this level of confidence by choosing the best input features with high interpretability and acceptable accuracy. The best feature selection out of a lot of input variables and preparing the rule base is again a very critical and challenging task in FRBCS. There is always a dilemma on judiciously choosing the number of input features for the FRBCS to achieve an optimized interpretable and accurate fuzzy system. It is always advisable to select least number of features with proper output error margin for a FRBCS. On adding extra features along with some rules as input to the system, certainly increases the accuracy

  12. Unit Sizing and Cost Analysis of Renewable Energy based Hybrid Power Generation System - A Case Study

    Directory of Open Access Journals (Sweden)

    Nitin AGARWAL

    2014-01-01

    Full Text Available A simulation model is developed for optimal sizing and analysis of a PV-diesel-battery based hybrid power generation system with the objectives to minimize life cycle cost and CO2 emission, while maintaining the desired system autonomy. A case study of a boy’s hostel in Moradabad district is taken for analysis purposes. It has 91 rooms with a capacity of 3 boys in each room. The decision variables included in the optimization methodology are total PV area, number of PV modules of 600 Wp, diesel generator power, fuel consumption per year and number of 24 V and 150 Ah batteries. The simulation result shows that the PV percentage of 86 % and diesel penetration of 14 % gives the most optimized solution with minimum LCC of $110,547 and average CO2 emission of 28 kg/day. The developed model has been validated by comparing its results with earlier research work.doi:10.14456/WJST.2014.24

  13. Wind Power Fluctuation Smoothing Controller Based on Risk Assessment of Grid Frequency Deviation in an Isolated System

    DEFF Research Database (Denmark)

    Lin, Jin; Sun, Yuanzhang; Song, Yonghua;

    2013-01-01

    Wind power fluctuation raises the security concern of grid frequency deviation, especially for an isolated power system. Thus, better control methodology needs to be developed to smooth the fluctuation without excessive spillage. Based on an actual industrial power system, this paper proposes...... loss, this paper designs a risk assessment model of grid frequency deviation, which is capable of locally estimating the maximum grid frequency deviation risk of the next dispatch cycle. A wind turbine speed optimizer then uses the estimated frequency deviation risk to search for the optimal power...

  14. Coordination of Series and Shunt Flexible Alternating Current Transmission Line System Devices Based Thyristor Controller for Improving Power System Stability

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2011-01-01

    Full Text Available Problem statement: Thyristor Controlled Series Capacitor (TCSC and Static Var Compensator (SVC have been individually applied to improve stability of power system. Approach: This study presents the coordination of a TCSC and SVC for improving power system stability. The swing curves of the three phase faulted power system with various cases are tested and compared. Results: The swing curve of system without FACTS devices has undamped oscillation. The system with a TCSC or a SVC can increase damping of power system whereas the system with coordination of a TCSC and a SVC provides the best results of stability improvement Conclusion: From the simulation results, the stability of power system can be much better improved by coordination control of a TCSC and a SVC.

  15. Coordination of Series and Shunt Flexible AC Transmission System Devices Based Voltage Source Converter for Improving Power System Stability

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2011-01-01

    Full Text Available Abstract: Problem statement: Static Synchronous Compensator (STATCOM and Static Synchronous Series Compensator (SSSC have been individually applied to improve stability of power system. Approach: This study presents the coordination of a STATCOM and SSSC for improving power system stability. The swing curves of the three phase faulted power system with various cases are tested and compared. Results: The swing curve of system without FACTS devices has undamped oscillation. The system with a STATCOM or a SSSC can increase damping of power system whereas the system with coordination of a STATCOM and a SSSC provides the best results of stability improvement Conclusion: From the simulation results, the stability of power system can be much better improved by coordination control of a STATCOM and a SSSC.

  16. A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems

    Science.gov (United States)

    Sun, Kai; Wu, Hongfei; Cai, Yan; Xing, Yan

    2014-06-01

    A thermoelectric generator (TEG) is a very important kind of power supply for spacecraft, especially for deep-space missions, due to its long lifetime and high reliability. To develop a practical TEG power supply for spacecraft, a power conditioning stage is indispensable, being employed to convert the varying output voltage of the TEG modules to a definite voltage for feeding batteries or loads. To enhance the system reliability, a power conditioning stage based on analog-circuit maximum-power-point tracking (MPPT) control and a superbuck converter is proposed in this paper. The input of this power conditioning stage is connected to the output of the TEG modules, and the output of this stage is connected to the battery and loads. The superbuck converter is employed as the main circuit, featuring low input current ripples and high conversion efficiency. Since for spacecraft power systems reliable operation is the key target for control circuits, a reset-set flip-flop-based analog circuit is used as the basic control circuit to implement MPPT, being much simpler than digital control circuits and offering higher reliability. Experiments have verified the feasibility and effectiveness of the proposed power conditioning stage. The results show the advantages of the proposed stage, such as maximum utilization of TEG power, small input ripples, and good stability.

  17. DISTRIBUTED GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEM EMISSION OFFSET ASSESSMENT: STATISTICAL TEST OF SIMULATED- AND MEASURED-BASED DATA

    Science.gov (United States)

    This study assessed the pollutant emission offset potential of distributed grid-connected photovoltaic (PV) power systems. Computer-simulated performance results were utilized for 211 PV systems located across the U.S. The PV systems' monthly electrical energy outputs were based ...

  18. Practical design of SMES controller for improving power system stability based on wide area synchronized phasor measurement

    Energy Technology Data Exchange (ETDEWEB)

    Dechanupaprittha, S.; Watanabe, M.; Mitani, Y. [Kyushu Inst. of Technology, Kitakyushu-shi, Fukuoka (Japan); Hongesombut, K. [Tokyo Electric Power Company, Tokyo (Japan); Ngamroo, I. [King Mongkut' s Inst. of Technhology, Ladkrabang (Thailand)

    2007-07-01

    Various load demands with abrupt changes adversely affects power system operations and control, which can lead to significant problems such as system frequency oscillations due to insufficient system damping. In interconnected power systems, a local frequency control is needed in a given area. In addition, fluctuations of tie-line power flow should be stabilized. Superconducting magnetic energy storage (SMES) can be used as an effective device to exchange electrical energy with a power system. Wide area monitoring of power systems based on multiple synchronized phasor measurements such as the phasor measurement unit (PMU) using the global positioning system (GPS) offers the possibility of data synchronization at a common time reference. With the GPS, oscillation modes can be detected from measured data by modeling measured data as a coupled vibration model (CVM). This paper presented a practical design of a SMES controller based on wide area synchronized phasor measurement. The CVM can be used to represents an estimated power system model that is used for tuning SMES controller parameters. In addition, it can be used to evaluate the performance and effectiveness of the designed controller in the power system. For the desired damping performance, the controller parameters were optimally tuned using a heuristic optimization method, called a TABU search algorithm. A simulation study was then conducted in order to show and confirm the effectiveness of the design method on a two-area four machine power system. The paper explained the controller design methodology and discussed the application to a two-area, four-machine power system. The simulation revealed that the proposed design method could be implemented in a practical manner. 11 refs., 3 tabs., 7 figs.

  19. 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.

  20. Fault Diagnosis Method Based on Fractal Theory and Its Application in Wind Power Systems

    Institute of Scientific and Technical Information of China (English)

    赵玲; 黄大荣; 宋军

    2012-01-01

    The non-linear dynamic theory brought a new method for recognizing and predicting complex non-linear dynamic behaviors. The non-linear behavior of vibration signals can be described by using fractal dimension quantitatively. In this paper, a fractal dimension calculation method for discrete signals in the fractal theory was applied to extract the fractal di- mension feature vectors and classified various fault types. Based on the wavelet packet transform, the energy feature vectors were extracted after the vibration signal was decomposed and reconstructed. Then, a wavelet neural network was used to recognize the mechanical faults. Finally, the fault diagnosis for a wind power system was taken as an example to show the method' s feasibility.

  1. Neural-net based unstable machine identification using individual energy functions. [Transient disturbances in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M. (Institut Nikola Tesla, Belgrade (Yugoslavia)); Sobajic, D.J.; Yohhan Pao (Case Western Reserve Univ., Cleveland, OH (United States))

    1991-10-01

    The identification of the mode of instability plays an essential role in generating principal energy boundary hypersurfaces. We present a new method for unstable machine identification based on the use of supervised learning neural-net technology, and the adaptive pattern recognition concept. It is shown that using individual energy functions as pattern features, appropriately trained neural-nets can retrieve the reliable characterization of the transient process including critical clearing time parameter, mode of instability and energy margins. Generalization capabilities of the neural-net processing allow for these assessments to be made independently of load levels. The results obtained from computer simulations are presented using the New England power system, as an example. (author).

  2. Robust SMES controller design based on inverse additive perturbation for stabilization of interconnected power systems with wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Ngamroo, Issarachai [Center of Excellence for Innovative Energy Systems, Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand)

    2010-03-15

    This paper proposes a robust controller design of Superconducting Magnetic Energy Storage (SMES) for stabilization of tie-line power oscillation in the interconnected power systems with wind farms. The inverse additive perturbation model is applied to represent system uncertainties such as several generating and loading conditions, variation of system parameters, wind power fluctuations, etc. The structure of active and reactive power controllers of SMES is the first-order lead-lag compensator. To tune the controller parameters, the optimization problem is formulated based on the enhancement of additive stability margin. The genetic algorithm is used to solve the problem and achieve the controller parameters. Simulation studies in the two-area four-machine interconnected power system with wind farms confirm the robustness of the proposed SMES under various operating conditions. (author)

  3. An LQG based PSS design for controlling the SSR in power systems with series-compensated lines

    Energy Technology Data Exchange (ETDEWEB)

    Seo, J.C.; Kim, T.H.; Park, J.K. [Seoul National Univ. (Korea, Republic of); Moon, S.I. [Chonbuk National Univ., Chonju (Korea, Republic of)

    1996-06-01

    This paper presents a linear quadratic Gaussian (LQG) based power system stabilizer (PSS) to control the subsynchronous resonance (SSR) that may occur in a series capacitor compensated power system. This paper investigates the dominant parameters on the SSR using the critical compensation level (CCL), and selects the design parameters to confirm the stability robustness. The complete SSR simulation system based on the IEEE first benchmark is employed in this study. Eigenvalue analysis and time domain simulations using a nonlinear system model show that the proposed PSS can control the SSR efficiently.

  4. Coordinated control of a DFIG-based wind-power generation system with SGSC under distorted grid voltage conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Li, Qing; Chen, Zhe;

    2013-01-01

    This paper presents a coordinated control method for a doubly-fed induction generator (DFIG)-based wind-power generation system with a series grid-side converter (SGSC) under distorted grid voltage conditions. The detailed mathematical models of the DFIG system with SGSC are developed in the mult......This paper presents a coordinated control method for a doubly-fed induction generator (DFIG)-based wind-power generation system with a series grid-side converter (SGSC) under distorted grid voltage conditions. The detailed mathematical models of the DFIG system with SGSC are developed...

  5. Dynamic Security Assessment of Western Danish Power System Based on Ensemble Decision Trees

    DEFF Research Database (Denmark)

    Liu, Leo; Bak, Claus Leth; Chen, Zhe;

    2014-01-01

    With the increasing penetration of renewable energy resources and other forms of dispersed generation, more and more uncertainties will be brought to the dynamic security assessment (DSA) of power systems. This paper proposes an approach that uses ensemble decision trees (EDT) for online DSA. Fed...... with outlier identification show high accuracy in the presence of variance and uncertainties due to wind power generation and other dispersed generation units. The performance of this approach is demonstrated on the operational model of western Danish power system with the scale of around 200 lines and 400...

  6. Configurable impedance matching to maximise power extraction for enabling self-powered system based-on photovoltaic cells

    Science.gov (United States)

    Rahman, Airul Azha Abd; Jamil, Wan Adil Wan; Umar, Akrajas Ali

    2016-07-01

    Multivariate energy harvesting system, solar and thermal energies, with configurable impedance matching features is presented. The system consists of a tuneable mechanism for peak performance tracking. The inputs are voltages ranging from 20 mV to 3.1 V. The matching load is individually tuned for photovoltaic and thermoelectric power efficiency not less than 80% and 50% of the open circuit voltage respectively. Of experimentation and analysis has been done, the time it takes to fully charge up to 3.4 V is 23 minutes with the rate of charging is 1.8 mV/sec. Empirical data is presented. [Figure not available: see fulltext.

  7. Optimization in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Geraldo R.M. da [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia

    1994-12-31

    This paper discusses, partially, the advantages and the disadvantages of the optimal power flow. It shows some of the difficulties of implementation and proposes solutions. An analysis is made comparing the power flow, BIGPOWER/CESP, and the optimal power flow, FPO/SEL, developed by the author, when applied to the CEPEL-ELETRONORTE and CESP systems. (author) 8 refs., 5 tabs.

  8. Power Systems Development Facility

    International Nuclear Information System (INIS)

    The objective of the PSDF would be to provide a modular facility which would support the development of advanced, pilot-scale, coal-based power systems and hot gas clean-up components. These pilot-scale components would be designed to be large enough so that the results can be related and projected to commercial systems. The facility would use a modular approach to enhance the flexibility and capability for testing; consequently, overall capital and operating costs when compared with stand-alone facilities would be reduced by sharing resources common to different modules. The facility would identify and resolve technical barrier, as well as-provide a structure for long-term testing and performance assessment. It is also intended that the facility would evaluate the operational and performance characteristics of the advanced power systems with both bituminous and subbituminous coals. Five technology-based experimental modules are proposed for the PSDF: (1) an advanced gasifier module, (2) a fuel cell test module, (3) a PFBC module, (4) a combustion gas turbine module, and (5) a module comprised of five hot gas cleanup particulate control devices. The final module, the PCD, would capture coal-derived ash and particles from both the PFBC and advanced gasifier gas streams to provide for overall particulate emission control, as well as to protect the combustion turbine and the fuel cell

  9. ADAPTIVE NEURO-FUZZY INFERENCE SYSTEM-PARTICLE SWARM OPTIMIZATION BASED STABILITY MAINTENANCE OF POWER SYSTEM NETWORKS

    Directory of Open Access Journals (Sweden)

    R. Latha

    2013-01-01

    Full Text Available During faulty condition voltage instability is one of the major crisis in power system networks. This study proposes a hybrid learning algorithm to improve the stability performance of a power system with Distributed Generations (DGs. Here the distribution system stability is maintained with reduced power loss using an Adaptive Neuro-Fuzzy Inference Systems (ANFIS and Particle Swarm Optimization (PSO techniques. In this study distributed generations is considered as several types of DGS connected together which is called as Microgrid (MG. Initially ANFIS is trained by instability parameters to give the optimal power capacity of the microgrid and then PSO algorithm is applied to find the optimum bus for connecting microgrid in the system. The effective improvements in voltage profile and reduction in power loss of the proposed ANFIS-PSO controller is tested on IEEE-30 bus system and has been presented with few comparative results.

  10. A Novel Evaluation Model for Hybrid Power System Based on Vague Set and Dempster-Shafer Evidence Theory

    Directory of Open Access Journals (Sweden)

    Dongxiao Niu

    2012-01-01

    Full Text Available Because clean energy and traditional energy have different advantages and disadvantages, it is of great significance to evaluate comprehensive benefits for hybrid power systems. Based on thorough analysis of important characters on hybrid power systems, an index system including security, economic benefit, environmental benefit, and social benefit is established in this paper. Due to advantages of processing abundant uncertain and fuzzy information, vague set is used to determine the decision matrix. Convert vague decision matrix to real one by vague combination ruleand determine uncertain degrees of different indexes by grey incidence analysis, then the mass functions of different comment set in different indexes are obtained. Information can be fused in accordance with Dempster-Shafer (D-S combination rule and the evaluation result is got by vague set and D-S evidence theory. A simulation of hybrid power system including thermal power, wind power, and photovoltaic power in China is provided to demonstrate the effectiveness and potential of the proposed design scheme. It can be clearly seen that the uncertainties in decision making can be dramatically decreased compared with existing methods in the literature. The actual implementation results illustrate that the proposed index system and evaluation model based on vague set and D-S evidence theory are effective and practical to evaluate comprehensive benefit of hybrid power system.

  11. Evaluation of Harmonic Content from a Tap Transformer Based Grid Connection System for Wind Power

    Directory of Open Access Journals (Sweden)

    S. Apelfröjd

    2013-01-01

    Full Text Available Simulations done in MATLAB/Simulink together with experiments conducted at the Ångströms laboratory are used to evaluate and discuss the total harmonic distortion (THD and total demand distortion (TDD of a tap transformer based grid connection system. The grid connection topology can be used with different turbine and generator topologies and is here applied on a vertical axis wind turbine (VAWT with a permanent magnet synchronous generator (PMSG and its operational scheme. The full variable-speed wind conversion system consists of a diode rectifier, DC link, IGBT inverter, LCL-filter, and tap transformer. The full variable-speed operation is enabled by the use of the different step-up ratios of the tap transformer. In the laboratory study, a full experimental setup of the system was used, a clone of the on-site PMSG driven by a motor was used, and the grid was replaced with a resistive load. With a resistive load, grid harmonics and possible unbalances are removed. The results show a TDD and THD below 5% for the full operating range and harmonic values within the limits set up by IEEE-519. Furthermore, a change in tap, going to a lower step-up ratio, results in a reduction in both THD and TDD for the same output power.

  12. Inductive-Based Wireless Power Recharging System for an Innovative Endoscopic Capsule

    Directory of Open Access Journals (Sweden)

    Giuseppe Tortora

    2015-09-01

    Full Text Available Wireless capsule endoscopic devices are adopted for painless diagnosis of cancer and other diseases affecting the gastrointestinal tract as an alternative to traditional endoscopy. Although much work has been done to improve capsule performance in terms of active navigation, a major drawback is the limited available energy on board the capsule, usually provided by a battery. Another key shortcoming of active capsules is their limitation in terms of active functionalities and related costs. An inductive-based wireless recharging system for the development of an innovative capsule for colonoscopy is proposed in this paper; the aim is to provide fast off-line battery recovery for improving capsule lifecycle and thus reducing the cost of a single endoscopic procedure. The wireless recharging system has been properly designed to fit the dimensions of a capsule for colonoscopy but it can be applied to any biomedical devices to increase the number of times it can be used after proper sterilization. The current system is able to provide about 1 W power and is able to recharge the battery capsule in 20 min which is a reasonable time considering capsule operation time (10–15 min.

  13. Fuel-Cell Power Systems Incorporating Mg-Based H2 Generators

    Science.gov (United States)

    Kindler, Andrew; Narayan, Sri R.

    2009-01-01

    Two hydrogen generators based on reactions involving magnesium and steam have been proposed as means for generating the fuel (hydrogen gas) for such fuel-cell power systems as those to be used in the drive systems of advanced motor vehicles. The hydrogen generators would make it unnecessary to rely on any of the hydrogen storage systems developed thus far that are, variously, too expensive, too heavy, too bulky, and/or too unsafe to be practical. The two proposed hydrogen generators are denoted basic and advanced, respectively. In the basic hydrogen generator (see figure), steam at a temperature greater than or equals 330 C would be fed into a reactor charged with magnesium, wherein hydrogen would be released in the exothermic reaction Mg + H2O yields MgO + H2. The steam would be made in a flash boiler. To initiate the reaction, the boiler could be heated electrically by energy borrowed from a storage battery that would be recharged during normal operation of the associated fuel-cell subsystem. Once the reaction was underway, heat from the reaction would be fed to the boiler. If the boiler were made an integral part of the hydrogen-generator reactor vessel, then the problem of transfer of heat from the reactor to the boiler would be greatly simplified. A pump would be used to feed water from a storage tank to the boiler.

  14. Power distribution system diagnosis with uncertainty information based on rough sets and clouds model

    Science.gov (United States)

    Sun, Qiuye; Zhang, Huaguang

    2006-11-01

    During the distribution system fault period, usually the explosive growth signals including fuzziness and randomness are too redundant to make right decision for the dispatcher. The volume of data with a few uncertainties overwhelms classic information systems in the distribution control center and exacerbates the existing knowledge acquisition process of expert systems. So intelligent methods must be developed to aid users in maintaining and using this abundance of information effectively. An important issue in distribution fault diagnosis system (DFDS) is to allow the discovered knowledge to be as close as possible to natural languages to satisfy user needs with tractability, and to offer DFDS robustness. At this junction, the paper describes a systematic approach for detecting superfluous data. The approach therefore could offer user both the opportunity to learn about the data and to validate the extracted knowledge. It is considered as a "white box" rather than a "black box" like in the case of neural network. The cloud theory is introduced and the mathematical description of cloud has effectively integrated the fuzziness and randomness of linguistic terms in a unified way. Based on it, a method of knowledge representation in DFDS is developed which bridges the gap between quantitative knowledge and qualitative knowledge. In relation to classical rough set, the cloud-rough method can deal with the uncertainty of the attribute and make a soft discretization for continuous ones (such as the current and the voltage). A novel approach, including discretization, attribute reduction, rule reliability computation and equipment reliability computation, is presented. The data redundancy is greatly reduced based on an integrated use of cloud theory and rough set theory. Illustrated with a power distribution DFDS shows the effectiveness and practicality of the proposed approach.

  15. The remote monitor and control system of power based on COM in HIRFL-CSR

    International Nuclear Information System (INIS)

    The design of power-system in HIRFL-CSR include two parts-design of hardware and software. We use COM module in this system to communicate message from Controlled devices to Front server's database, and communicate between web server and center Oracle database. This system makes the operators control devices remotely. And it also makes the data dealt with easily, saves the cost in realization of system. (authors)

  16. Power system analysis

    CERN Document Server

    Murty, PSR

    2007-01-01

    Power system analysis is a pre-requisite course for electrical engineering students. This book introduces concepts of a power system, network model faults and analysis and the primitive network stability. It also deals with graph theory relevant to various incidence matrices, building of network matrices and power flow studies. It further discusses with short circuit analysis, unbalanced fault analysis and power system stability problems, such as, steady state stability, transient stability and dynamic stability. Salient Features: Number of worked examples are followed after explaining theory

  17. Power system state estimation

    CERN Document Server

    Ahmad, Mukhtar

    2012-01-01

    State estimation is one of the most important functions in power system operation and control. This area is concerned with the overall monitoring, control, and contingency evaluation of power systems. It is mainly aimed at providing a reliable estimate of system voltages. State estimator information flows to control centers, where critical decisions are made concerning power system design and operations. This valuable resource provides thorough coverage of this area, helping professionals overcome challenges involving system quality, reliability, security, stability, and economy.Engineers are

  18. Systems and methods for providing power to a load based upon a control strategy

    Science.gov (United States)

    Perisic, Milun; Kajouke, Lateef A; Ransom, Ray M

    2013-12-24

    Systems and methods are provided for an electrical system. The electrical system includes a load, an interface configured to receive a voltage from a voltage source, and a controller configured to receive the voltage from the voltage source through the interface and to provide a voltage and current to the load. Wherein, when the controller is in a constant voltage mode, the controller provides a constant voltage to the load, when the controller is in a constant current mode, the controller provides a constant current to the load, and when the controller is in a constant power mode, the controller provides a constant power to the load.

  19. Vibration control of multi-degrees-of-freedom system with dynamic absorbers based on power flow

    Institute of Scientific and Technical Information of China (English)

    WANG Quanjuan; HUANG Wenhua; XIA Songbo; LI Jimin; SUN Zhizhuo

    2003-01-01

    In accordance with a multiple degrees of freedom vibration system with dynamicvibration absorbers (DVAs), an equivalent admittance matrix and the power flows input majorstructure and minor structure are deduced on the basis of the theories of structure mobility.Furthermore, regarding the net power flow of main vibration system as the controlled object,probed into are the single and multiple model controls of multi-degrees-of-freedom system withone or several absorbers attached. And the control mechanism and effect of dynamic vibrationabsorbers are revealed.

  20. Neural net based determination of generator-shedding requirements in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M. (Electrical Engineering Inst. ' Nikola Tesla' , Belgrade (Yugoslavia)); Sobajic, D.J.; Pao, Y.-H. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE Inc., Cleveland, OH (United States))

    1992-09-01

    This paper presents an application of artificial neural networks (ANN) in support of a decision-making process by power system operators directed towards the fast stabilisation of multi-machine systems. The proposed approach considers generator shedding as the most effective discrete supplementary control for improving the dynamic performance of faulted power systems and preventing instabilities. The sensitivity of the transient energy function (TEF) with respect to changes in the amount of dropped generation is used during the training phase of ANNs to assess the critical amount of generator shedding required to prevent the loss of synchronism. The learning capabilities of neural nets are used to establish complex mappings between fault information and the amount of generation to be shed, suggesting it as the control signal to the power system operator. (author)

  1. Immersion and Invariance-Based Coordinated Generator Excitation and SVC Control for Power Systems

    Directory of Open Access Journals (Sweden)

    Adirak Kanchanaharuthai

    2014-01-01

    Full Text Available A nonlinear coordinated control of excitation and SVC of an electrical power system is proposed for transient stability, and voltage regulation enhancement after the occurrence of a large disturbance and a small perturbation. Using the concept of Immersion and Invariance (I&I design methodology, the proposed nonlinear controller is used to not only achieve power angle stability, frequency and voltage regulation but also ensure that the closed-loop system is transiently and asymptotically stable. In order to show the effectiveness of the proposed controller design, the simulation results illustrate that, in spite of the case where a large perturbation occurs on the transmission line or there is a small perturbation to mechanical power inputs, the proposed controller can not only keep the system transiently stable but also simultaneously accomplish better dynamic properties of the system as compared to operation with the existing controllers designed through a coordinated passivation technique controller and a feedback linearization scheme, respectively.

  2. A vacuum tolerant high voltage system with a low noise and low power Cockcroft–Walton photomultiplier base

    OpenAIRE

    Masuda, T.; Iwai, E.; Kawasaki, N; Kim, E. J.; Komatsubara, T. K.; Lee, J.W.; Lim, G. Y.; Maeda, Y.; Naito, D.; Nanjo, H.; Nomura, T.; Ri, Y. D.; Sasao, N.; Sato, K.; Seki, S.

    2014-01-01

    We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft–Walton (CW) photomultiplier tube base with a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1 MeV range. We achieved a final noise level below 180 μV[rms] for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases p...

  3. Estimation of Power/Energy Losses in Electric Distribution Systems based on an Efficient Method

    Directory of Open Access Journals (Sweden)

    Gheorghe Grigoras

    2013-09-01

    Full Text Available Estimation of the power/energy losses constitutes an important tool for an efficient planning and operation of electric distribution systems, especially in a free energy market environment. For further development of plans of energy loss reduction and for determination of the implementation priorities of different measures and investment projects, analysis of the nature and reasons of losses in the system and in its different parts is needed. In the paper, an efficient method concerning the power flow problem of medium voltage distribution networks, under condition of lack of information about the nodal loads, is presented. Using this method it can obtain the power/energy losses in power transformers and the lines. The test results, obtained for a 20 kV real distribution network from Romania, confirmed the validity of the proposed method.  

  4. Reducing Dynamic Power and Leakage Power for Embedded Systems

    OpenAIRE

    Yasuura, Hiroto

    2002-01-01

    This paper presents a system-level technique for embedded processor-based systems targeting both dynamic power and leakage power reduction using datapath width optimization. By means of tuning the design parameter, datapath width tailored to a given application requirements, the processors and memories are optimized resulting in significant power reduction, not only for dynamic power but also for leakage power. In our experiments for several real embedded applications, power reduction without...

  5. A new paradigm on battery powered embedded system design based on User-Experience-Oriented method

    International Nuclear Information System (INIS)

    The battery sustainable time has been an active research topic recently for the development of battery powered embedded products such as tablets and smart phones, which are determined by the battery capacity and power consumption. Despite numerous efforts on the improvement of battery capacity in the field of material engineering, the power consumption also plays an important role and easier to ameliorate in delivering a desirable user-experience, especially considering the moderate advancement on batteries for decades. In this study, a new Top-Down modelling method, User-Experience-Oriented Battery Powered Embedded System Design Paradigm, is proposed to estimate the target average power consumption, to guide the hardware and software design, and eventually to approach the theoretical lowest power consumption that the application is still able to provide the full functionality. Starting from the 10-hour sustainable time standard, average working current is defined with battery design capacity and set as a target. Then an implementation is illustrated from both hardware perspective, which is summarized as Auto-Gating power management, and from software perspective, which introduces a new algorithm, SleepVote, to guide the system task design and scheduling

  6. A contract-based methodology for aircraft electric power system design

    OpenAIRE

    Nuzzo, P; H. Xu; Ozay, N; Finn, JB; Sangiovanni-Vincentelli, AL; Murray, RM; Donzé, A; Seshia, SA

    2014-01-01

    In an aircraft electric power system, one or more supervisory control units actuate a set of electromechanical switches to dynamically distribute power from generators to loads, while satisfying safety, reliability, and real-time performance requirements. To reduce expensive redesign steps, this control problem is generally addressed by minor incremental changes on top of consolidated solutions. A more systematic approach is hindered by a lack of rigorous design methodologies that allow estim...

  7. The vulnerability of laser warning systems against guided weapons based on low power lasers

    OpenAIRE

    Al-Jaberi, Mubarak

    2006-01-01

    Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current ...

  8. Qualitative Event-based Diagnosis with Possible Conflicts Applied to Spacecraft Power Distribution Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based diagnosis enables efficient and safe operation of engineered systems. In this paper, we describe two algorithms based on a qualitative event-based fault...

  9. Predictive control of a back-to-back NPC converter-based wind power system

    OpenAIRE

    Calle Prado, Alejandro; Alepuz Menéndez, Salvador; Bordonau Farrerons, José; Cortés, Patricio; Rodriguez, Jose

    2016-01-01

    © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works As wind power technology points to increase power ratings, the implementation based on a permanent-magnet synch...

  10. Experimental Study on Cloud-Computing-Based Electric Power SCADA System

    Institute of Scientific and Technical Information of China (English)

    Yongbo Chen; Jijun Chen; Jiafeng Gan

    2015-01-01

    With the development of smart grid, the electric power supervisory control and data acquisition (SCADA) system is limited by the traditional IT infrastructure, leading to low resource utilization and poor scalability. Information islands are formed due to poor sys⁃tem interoperability. The development of innovative applications is limited, and the launching period of new businesses is long. Management costs and risks increase, and equipment utilization declines. To address these issues, a professional private cloud so⁃lution is introduced to integrate the electric power SCADA system, and conduct experimental study of its applicability, reliability, security, and real time. The experimental results show that the professional private cloud solution is technical and commercial fea⁃sible, meeting the requirements of the electric power SCADA system.

  11. Area-Based COI-Referred Rotor Angle Index for Transient Stability Assessment and Control of Power Systems

    Directory of Open Access Journals (Sweden)

    Noor Izzri Abdul Wahab

    2012-01-01

    Full Text Available This paper describes an index for judging the severity of transient events of power systems in simulation. The proposed transient stability index, known as the area-based COI-referred rotor angle index, is developed by considering the fact that a large-sized power system is divided into several areas according to the coherency of generators in a particular area. It can be assumed that an equivalent single large machine can represent all the generators in that area. Thus, the assessment of rotor angles for all generators can be simplified by only assessing the index of areas in a power system. The effectiveness of the proposed index in assessing the stability of power systems and its ability in pinpointing the weakest area in the power system is analyzed. Furthermore, this paper developed an emergency control scheme known as the combined UFLS and generator tripping in order to stabilize the system when unstable faults occurred in a power system. The proposed index is used to identify the generator to be tripped when the developed emergency control scheme operates. The performance of the proposed index and the combined UFLS and generator tripping scheme are evaluated on the IEEE 39-bus test system.

  12. Development of a Forward/Backward Power Flow Algorithm in Distribution Systems Based on Probabilistic Technique Using Normal Distribution

    Directory of Open Access Journals (Sweden)

    Shahrokh Shojaeian

    2014-01-01

    Full Text Available There are always some uncertainties in prediction and estimation of distribution systems loads. These uncertainties impose some undesirable impacts and deviations on power flow of the system which may cause reduction in accuracy of the results obtained by system analysis. Thus, probabilistic analysis of distribution system is very important. This paper proposes a probabilistic power flow technique by applying a normal probabilistic distribution in seven standard deviations on forward-backward algorithm. The losses and voltage of IEEE 33-bus test distribution network is investigated by our new algorithm and the results are compared with the conventional algorithm i.e., based on deterministic methods.

  13. Optimization design of the stratospheric airship's power system based on the methodology of orthogonal experiment

    Institute of Scientific and Technical Information of China (English)

    Jian LIU; Quan-bao WANG; Hai-tao ZHAO; Ji-an CHEN; Ye QIU; Deng-ping DUAN

    2013-01-01

    The optimization design of the power system is essential for stratospheric airships with paradoxical requirements of high reliability and low weight.The methodology of orthogonal experiment is presented to deal with the problem of the optimization design of the airship's power system.Mathematical models of the solar array,regenerative fuel cell,and power management subsystem (PMS) are presented.The basic theory of the method of orthogonal experiment is discussed,and the selection of factors and levels of the experiment and the choice of the evaluation function are also revealed.The proposed methodology is validated in the optimization design of the power system of the ZhiYuan-2 stratospheric airship.Results show that the optimal configuration is easily obtained through this methodology.Furthermore,the optimal configuration and three sub-optimal configurations are in the Pareto frontier of the design space.Sensitivity analyses for the weight and reliability of the airship's power system are presented.

  14. Study of regeneration system of 300 MW power unit based on nondeaerating heat balance diagram at reduced load

    Science.gov (United States)

    Esin, S. B.; Trifonov, N. N.; Sukhorukov, Yu. G.; Yurchenko, A. Yu.; Grigor'eva, E. B.; Snegin, I. P.; Zhivykh, D. A.; Medvedkin, A. V.; Ryabich, V. A.

    2015-09-01

    More than 30 power units of thermal power stations, based on the nondeaerating heat balance diagram, successfully operate in the former Soviet Union. Most of them are power units with a power of 300 MW, equipped with HTGZ and LMZ turbines. They operate according to a variable electric load curve characterized by deep reductions when undergoing night minimums. Additional extension of the range of power unit adjustment makes it possible to maintain the dispatch load curve and obtain profit for the electric power plant. The objective of this research is to carry out estimated and experimental processing of the operating regimes of the regeneration system of steam-turbine plants within the extended adjustment range and under the conditions when the constraints on the regeneration system and its equipment are removed. Constraints concerning the heat balance diagram that reduce the power unit efficiency when extending the adjustment range have been considered. Test results are presented for the nondeaerating heat balance diagram with the HTGZ turbine. Turbine pump and feed electric pump operation was studied at a power unit load of 120-300 MW. The reliability of feed pump operation is confirmed by a stable vibratory condition and the absence of cavitation noise and vibration at a frequency that characterizes the cavitation condition, as well as by oil temperature maintenance after bearings within normal limits. Cavitation performance of pumps in the studied range of their operation has been determined. Technical solutions are proposed on providing a profitable and stable operation of regeneration systems when extending the range of adjustment of power unit load. A nondeaerating diagram of high-pressure preheater (HPP) condensate discharge to the mixer. A regeneration system has been developed and studied on the operating power unit fitted with a deaeratorless thermal circuit of the system for removing the high-pressure preheater heating steam condensate to the mixer

  15. Frequency control system based on power factor control of asynchronous motor

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-chun; YANG Fei-xia; REN Zhi-ling

    2005-01-01

    Deduced the relationship between the power factor (PF) and the angular frequency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experiment results show that it has a good self-adaptation in the whole scope of speed adjustment and an obvious economization on energy while it runs under load.

  16. 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 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...... 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...

  17. Power reactor information system (PRIS)

    International Nuclear Information System (INIS)

    Since the very beginning of commercial operation of nuclear power plants, the nuclear power industry worldwide has accumulated more than 5000 reactor years of experience. The IAEA has been collecting Operating Experience data for Nuclear Power Plants since 1970 which were computerized in 1980. The Agency has undertaken to make Power Reactor Information System (PRIS) available on-line to its Member States. The aim of this publication is to provide the users of PRIS from their terminals with description of data base and communication systems and to show the methods of accessing the data

  18. Performance analysis of CDMA power control system based on fuzzy prediction

    Institute of Scientific and Technical Information of China (English)

    杨涛; 谢剑英

    2004-01-01

    Power control is of paramount importance in combating the near-far problem and co-channel interference in a CDMA cellular system. Due to fast fading and ambient interference in a wireless channel, conventional fixed-step power control schemes have difficulty in compensating for the fast fading channel dynamically and in a timely manner. To acquire flexible power regulation in order to maintain required transmission capacity under the given transmission quality requirement, we propose a hybrid power control scheme which makes full use of the simple fuzzy inference rule refined by an operator in the fuzzy control and prediction property from related previous results in Generalized Prediction Control (GPC). In implementation of this strategy, we classify the fading zone into three levels according to the signal-to-noise-rate (SNR) requirement. In each level the power compensation amount varies with fading gradient and the compensation scheme varies as well. The digital results show that adoption of the fuzzy-GPC power regulation scheme has acquired a reasonable performance improvement when compared with fixed-step and fuzzy schemes. According to theoretic analysis and simulation results,we can conclude that under a variational transmission environment, a flexible power regulation scheme such as fuzzy-GPC is easy to adapt to the environment and thus overcomes the near-far effect and multi-access interference effectively.

  19. A novel optimization method of transient stability emergency control based on practical dynamic security region (PDSR) of power systems

    Institute of Scientific and Technical Information of China (English)

    YU; Yixin; LIU; Hui; ZENG; Yuan

    2004-01-01

    This paper proposes a novel optimization method of transient stability emergency control based on a new concept of the so-called extended practical dynamic security region (EPDSR) defined in this paper and four experiential laws about the EPDSRs found from a number of studies in real power systems. In this method, the effect of a control action is represented by the displacement of EPDSR's critical hyper-plane boundary in the direction of its outer normal vector. If an unstable contingency occurs, appropriate emergency control actions are triggered so that the enlarged EPDSR can cover the current operating point. Based on these ideas, a mathematics model of emergency control strategy is developed for minimizing its total cost and guaranteeing power system transient stability. The simulation results on the 10-generator, 39-bus New-England Test System as well as other real power systems have shown the validity of this method.

  20. A decision tree-based on-line preventive control strategy for power system transient instability prevention

    Science.gov (United States)

    Xu, Yan; Dong, Zhao Yang; Zhang, Rui; Wong, Kit Po

    2014-02-01

    Maintaining transient stability is a basic requirement for secure power system operations. Preventive control deals with modifying the system operating point to withstand probable contingencies. In this article, a decision tree (DT)-based on-line preventive control strategy is proposed for transient instability prevention of power systems. Given a stability database, a distance-based feature estimation algorithm is first applied to identify the critical generators, which are then used as features to develop a DT. By interpreting the splitting rules of DT, preventive control is realised by formulating the rules in a standard optimal power flow model and solving it. The proposed method is transparent in control mechanism, on-line computation compatible and convenient to deal with multi-contingency. The effectiveness and efficiency of the method has been verified on New England 10-machine 39-bus test system.

  1. Developments of integrity evaluation technology for pressurized components in nuclear power plant and IT based integrity evaluation system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Choi, Jae Boong; Shim, Do Jun [Sungkyunkwan Univ., Seoul (Korea, Republic of)] (and others)

    2003-03-15

    The objective of this research is to develop an efficient evaluation technology and to investigate applicability of newly-developed technology, such as internet-based cyber platform, to operating power plants. Development of efficient evaluation systems for Nuclear Power Plant components, based on structural integrity assessment techniques, are increasingly demanded for safe operation with the increasing operating period of Nuclear Power Plants. The following five topics are covered in this project: development of assessment method for wall-thinned nuclear piping based on pipe test; development of structural integrity program for steam generator tubes with cracks of various shape; development of fatigue life evaluation system for mam components of NPP; development of internet-based cyber platform and integrity program for primary components of NPP; effect of aging on strength of dissimilar welds.

  2. 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.

  3. A Method of MPPT Control Based on Power Variable Step-size in Photovoltaic Converter System

    Directory of Open Access Journals (Sweden)

    Xu Hui-xiang

    2016-01-01

    Full Text Available Since the disadvantage of traditional MPPT algorithms of variable step-size, proposed power tracking based on variable step-size with the advantage method of the constant-voltage and the perturb-observe (P&O[1-3]. The control strategy modify the problem of voltage fluctuation caused by perturb-observe method, at the same time, introducing the advantage of constant-voltage method and simplify the circuit topology. With the theoretical derivation, control the output power of photovoltaic modules to change the duty cycle of main switch. Achieve the maximum power stabilization output, reduce the volatility of energy loss effectively, and improve the inversion efficiency[3,4]. Given the result of experimental test based theoretical derivation and the curve of MPPT when the prototype work.

  4. Power Electronic Systems for Switched Reluctance Generator based Wind Farms and DC Networks

    DEFF Research Database (Denmark)

    Park, Kiwoo

    . Under these circumstances, research on dc network connection with a novel wind power generator system is presented in this thesis, which mainly consists of two major parts: control of a Switched Reluctance Generator (SRG) system and development of dc-dc converters for a dc network system in a wind farm...... are presented to verify the feasibility and operational principles of the proposed converters. Finally, modelling and control of a dc-grid wind farm using one of the proposed dc-dc converters are presented. An average model provides insight into the overall performance of the system. Meanwhile, a switching....... The SRG, which eliminates permanent magnets, brushes, commutators, and coil winding in the rotor, could be a promising wind power generator. It has various desirable features, such as simple and solid structure, easiness of maintenance, fault tolerance, and low cost. These features are suitable...

  5. A Fuzzy-Logic Power Management Strategy Based on Markov Random Prediction for Hybrid Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Yanzi Wang

    2016-01-01

    Full Text Available Over the last few years; issues regarding the use of hybrid energy storage systems (HESSs in hybrid electric vehicles have been highlighted by the industry and in academic fields. This paper proposes a fuzzy-logic power management strategy based on Markov random prediction for an active parallel battery-UC HESS. The proposed power management strategy; the inputs for which are the vehicle speed; the current electric power demand and the predicted electric power demand; is used to distribute the electrical power between the battery bank and the UC bank. In this way; the battery bank power is limited to a certain range; and the peak and average charge/discharge power of the battery bank and overall loss incurred by the whole HESS are also reduced. Simulations and scaled-down experimental platforms are constructed to verify the proposed power management strategy. The simulations and experimental results demonstrate the advantages; feasibility and effectiveness of the fuzzy-logic power management strategy based on Markov random prediction.

  6. Knowledge based support for real time application of multiagent control and automation in electric power systems

    DEFF Research Database (Denmark)

    Saleem, Arshad; Nordstrom, Lars; Lind, Morten

    2011-01-01

    for reasoning about control situations. The proposed mechanism has been used in different scenarios of electric power distribution system protection and control. Results show that agents can use local models of their environment and coordinate with other agents to analyze and understand a disturbance situation...

  7. TCSC Nonlinear Adaptive Damping Controller Design Based on RBF Neural Network to Enhance Power System Stability

    DEFF Research Database (Denmark)

    Yao, Wei; Fang, Jiakun; Zhao, Ping;

    2013-01-01

    the characteristics of the conventional PID, but adjust the parameters of PID controller online using identified Jacobian information from RBFNN. Hence, it has strong adaptability to the variation of the system operating condition. The effectiveness of the proposed controller is tested on a two-machine five-bus power...

  8. Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power

    NARCIS (Netherlands)

    Kaiser, J.W.; Heil, A.; Andreae, M.O.; Benedetti, A.; Chubarova, N.; Jones, L.; Morcrette, J.J.; Razinger, M.; Schultz, M.G.; Suttie, M.; Werf, van der G.R.

    2012-01-01

    The Global Fire Assimilation System (GFASv1.0) calculates biomass burning emissions by assimilating Fire Radiative Power (FRP) observations from the MODIS instruments onboard the Terra and Aqua satellites. It corrects for gaps in the observations, which are mostly due to cloud cover, and filters spu

  9. FEMAN: Fuzzy-Based Energy Management System for Green Houses Using Hybrid Grid Solar Power

    Directory of Open Access Journals (Sweden)

    Abdellah Chehri

    2013-01-01

    Full Text Available The United Nations has designated the year 2012 as the international year of sustainable energy. Today, we are seeing a rise in global awareness of energy consumption and environmental problems. Many nations have launched different programs to reduce the energy consumption in residential and commercial buildings to seek lower-carbon energy solutions. We are talking about the future green and smart houses. The subject of smart/green houses is not one of “why,” but rather “how,” specifically: “how making the future house more energy efficient.” The use of the renewable energy, the technology and the services could help us to answer this question. Intelligent home energy management is an approach to build centralized systems that deliver application functionality as services to end-consumer applications. The objective of this work is to develop a smart and robust controller for house energy consumption with maximizing the use of solar energy and reducing the impact on the power grid while satisfying the energy demand of house appliances. We proposed a fuzzy-based energy management controller in order to reduce the consumed energy of the building while respecting a fixed comfort.

  10. Genetic Algorithms for Optimal Reactive Power Compensation of a Power System with Wind Generators based on Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    L. Krichen

    2007-03-01

    Full Text Available In this paper, we develop a method to maintain an acceptable voltages profile and minimization of active losses of a power system including wind generators in real time. These tasks are ensured by acting on capacitor and inductance benches implemented in the consuming nodes. To solve this problem, we minimize an objective function associated to active losses under constraints imposed on the voltages and the reactive productions of the various benches. The minimization procedure was realised by the use of genetic algorithms (GA. The major disadvantage of this technique is that it requires a significant computing time thus not making it possible to deal with the problem in real time. After a training phase, a neural model has the capacity to provide a good estimation of the voltages, the reactive productions and the losses for forecast curves of the load and the wind speed, in real time.

  11. DEVELOP A CONCENTRATED SOLAR POWER-BASED THERMAL COOLING SYSTEM VIA SIMULATION AND EXPERIMENTAL STUDIES

    Science.gov (United States)

    A small scale CSP-based cooling system prototype (300W cooling capacity) and the system performance simulation tool will be developed as a proof of concept. Practical issues will be identified to improve our design.

  12. Converters for Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng

    2015-01-01

    presents an overview of the power converters for the DPGS, mainly based on wind turbine systems and photovoltaic systems, covering a wide range of applications. Moreover, the modulation schemes and interfacing power filters for the power converters are also exemplified. Finally, the general control......Power electronics technology has become the enabling technology for the integration of distributed power generation systems (DPGS) such as offshore wind turbine power systems and commercial photovoltaic power plants. Depending on the applications, a vast array of DPGS-based power converter...

  13. Hard- and software of real time simulation tools of Electric Power System for adequate modeling power semiconductors in voltage source convertor based HVDC and FACTS

    Directory of Open Access Journals (Sweden)

    Ufa Ruslan A.

    2014-01-01

    Full Text Available The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of Flexible Alternating Current Transmission System (FACTS devices and High Voltage Direct Current Transmission (HVDC system as part of real electric power systems (EPS. For that, a hybrid approach for advanced simulation of the FACTS and HVDC based on Voltage Source is proposed. The presented simulation results of the developed hybrid model of VSC confirm the achievement of the desired properties of the model and the effectiveness of the proposed solutions.

  14. Design of Anti-Windup Compensator for Energy Storage-Based Damping Controller to Enhance Power System Stability

    DEFF Research Database (Denmark)

    Fang, Jiakun; Yao, Wei; Chen, Zhe;

    2014-01-01

    , produces a signal based on the output difference between the ESDC and saturated ES and augment the signal to the ESDC to alleviate the adverse effect of saturation. The AWC is designed with the reduced-order model of power system and linear matrix inequality. Detailed design procedure is introduced. Case......The application of energy storage (ES) in power system is limited due to the high cost of the ES device, which exponentially increases with its capacity. This paper is to improve the saturation-dependent stability of the power system equipped with the energy storage based damping controller (ESDC......), and hence, reduce the required size of ES. The phenomenon that the capacity of ES is smaller than the required value produced by the ESDC, is modeled as actuator saturation using the saturation function. The proposed method is to design a anti-windup compensator (AWC), which in the event of saturation...

  15. Power Systems Without Fuel

    OpenAIRE

    Taylor, Joshua Adam; Dhople, Sairaj V.; Callaway, Duncan S.

    2015-01-01

    The finiteness of fossil fuels implies that future electric power systems may predominantly source energy from fuel-free renewable resources like wind and solar. Evidently, these power systems without fuel will be environmentally benign, sustainable, and subject to milder failure scenarios. Many of these advantages were projected decades ago with the definition of the soft energy path, which describes a future where all energy is provided by numerous small, simple, and diverse renewable sourc...

  16. Compressed sensing based joint-compensation of power amplifier's distortions in OFDMA cognitive radio systems

    KAUST Repository

    Ali, Anum Z.

    2013-12-01

    Linearization of user equipment power amplifiers driven by orthogonal frequency division multiplexing signals is addressed in this paper. Particular attention is paid to the power efficient operation of an orthogonal frequency division multiple access cognitive radio system and realization of such a system using compressed sensing. Specifically, precompensated overdriven amplifiers are employed at the mobile terminal. Over-driven amplifiers result in in-band distortions and out of band interference. Out of band interference mostly occupies the spectrum of inactive users, whereas the in-band distortions are mitigated using compressed sensing at the receiver. It is also shown that the performance of the proposed scheme can be further enhanced using multiple measurements of the distortion signal in single-input multi-output systems. Numerical results verify the ability of the proposed setup to improve error vector magnitude, bit error rate, outage capacity and mean squared error. © 2011 IEEE.

  17. Decentralized model predictive based load frequency control in an interconnected power system

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, T.H., E-mail: tarekhie@yahoo.co [High Institute of Energy, South Valley University (Egypt); Bevrani, H., E-mail: bevrani@ieee.or [Dept. of Electrical Engineering and Computer Science, University of Kurdistan (Iran, Islamic Republic of); Hassan, A.A., E-mail: aahsn@yahoo.co [Faculty of Engineering, Dept. of Electrical Engineering, Minia University, Minia (Egypt); Hiyama, T., E-mail: hiyama@cs.kumamoto-u.ac.j [Dept. of Electrical Engineering and Computer Science, Kumamoto University, Kumamoto (Japan)

    2011-02-15

    This paper presents a new load frequency control (LFC) design using the model predictive control (MPC) technique in a multi-area power system. The MPC technique has been designed such that the effect of the uncertainty due to governor and turbine parameters variation and load disturbance is reduced. Each local area controller is designed independently such that stability of the overall closed-loop system is guaranteed. A frequency response model of multi-area power system is introduced, and physical constraints of the governors and turbines are considered. The model was employed in the MPC structures. Digital simulations for both two and three-area power systems are provided to validate the effectiveness of the proposed scheme. The results show that, with the proposed MPC technique, the overall closed-loop system performance demonstrated robustness in the face of uncertainties due to governors and turbines parameters variation and loads disturbances. A performance comparison between the proposed controller and a classical integral control scheme is carried out confirming the superiority of the proposed MPC technique.

  18. Development of a web-based monitoring system using operation parameters for the main component in nuclear power plants

    International Nuclear Information System (INIS)

    The frequency of the damage is increasing, which is caused by the fatigue, according to the increase of running of nuclear power plants. So we need to acquire the reliance of design data to estimate the fatigue and damage of major machinery that might happen as time-dependent crack growth characterization. The research is focused on keeping operating record of nuclear power plants about major machinery which consists of a nuclear reactor pressure boarder on each excessive operating condition including normal operating and extraordinary operating by estimating fracture mechanical movements on real time and fatigue about major nuclear power plants machinery, which are acquired the pressure and temperature data. For further details about the scope and contents of R and D are following. Development of H/W that is necessary to acquire operating real time data of heating and hydraulic power. Selection of a safety variable about major system by each type (the four NPP, all unit). Communication protocol development for connecting between CARE system data base server and fatigue monitoring system data base server. Development of connecting database for controlling and storing of heating and hydraulic power operating data. Real time monitoring system development based on Web using JAVA

  19. Development of a web-based monitoring system using operation parameters for the main component in nuclear power plants

    International Nuclear Information System (INIS)

    The frequency of the damage is increasing, which is caused by the fatigue, according to the increase of running of nuclear power plants. So we need to acquire the reliance of design data to estimate the fatigue and damage of major machinery that might happen as time-dependent crack growth characterization. The research is focused on keeping operating record of nuclear power plants about major machinery which consists of a nuclear reactor pressure boarder on each excessive operating condition including normal operating and extraordinary operating by estimating fracture mechanical movements on real time and fatigue about major nuclear power plants machinery, which are acquired the pressure and temperature data. For further details about the scope and contents of R and D are following: development of H/W that is necessary to acquire operating real time data of heating and hydraulic power, selection of a safety variable about major system by each type (the fourth unit), communication protocol development for connecting between CARE system data base server and fatigue monitoring system data base server, development of connecting database for controlling and storing of heating and hydraulic power operating data, real time monitoring system development based on web using JAVA

  20. Development of a web-based monitoring system using operation parameters for the main component in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Son, Dong Chan; An, Kung Il; Hong, Suk Young; Lee, Jeong Soo; Jung, Duk Jin; Shin, Sun Hee; Son, So Hee [Daesang Information Technology Co., Ltd., Seoul (Korea, Republic of)

    2004-02-15

    The frequency of the damage is increasing, which is caused by the fatigue, according to the increase of running of nuclear power plants. So we need to acquire the reliance of design data to estimate the fatigue and damage of major machinery that might happen as time-dependent crack growth characterization. The research is focused on keeping operating record of nuclear power plants about major machinery which consists of a nuclear reactor pressure boarder on each excessive operating condition including normal operating and extraordinary operating by estimating fracture mechanical movements on real time and fatigue about major nuclear power plants machinery, which are acquired the pressure and temperature data. For further details about the scope and contents of R and D are following. Development of H/W that is necessary to acquire operating real time data of heating and hydraulic power. Selection of a safety variable about major system by each type (the four NPP, all unit). Communication protocol development for connecting between CARE system data base server and fatigue monitoring system data base server. Development of connecting database for controlling and storing of heating and hydraulic power operating data. Real time monitoring system development based on Web using JAVA.

  1. Optimization-based power management of hybrid power systems with applications in advanced hybrid electric vehicles and wind farms with battery storage

    Science.gov (United States)

    Borhan, Hoseinali

    Modern hybrid electric vehicles and many stationary renewable power generation systems combine multiple power generating and energy storage devices to achieve an overall system-level efficiency and flexibility which is higher than their individual components. The power or energy management control, "brain" of these "hybrid" systems, determines adaptively and based on the power demand the power split between multiple subsystems and plays a critical role in overall system-level efficiency. This dissertation proposes that a receding horizon optimal control (aka Model Predictive Control) approach can be a natural and systematic framework for formulating this type of power management controls. More importantly the dissertation develops new results based on the classical theory of optimal control that allow solving the resulting optimal control problem in real-time, in spite of the complexities that arise due to several system nonlinearities and constraints. The dissertation focus is on two classes of hybrid systems: hybrid electric vehicles in the first part and wind farms with battery storage in the second part. The first part of the dissertation proposes and fully develops a real-time optimization-based power management strategy for hybrid electric vehicles. Current industry practice uses rule-based control techniques with "else-then-if" logic and look-up maps and tables in the power management of production hybrid vehicles. These algorithms are not guaranteed to result in the best possible fuel economy and there exists a gap between their performance and a minimum possible fuel economy benchmark. Furthermore, considerable time and effort are spent calibrating the control system in the vehicle development phase, and there is little flexibility in real-time handling of constraints and re-optimization of the system operation in the event of changing operating conditions and varying parameters. In addition, a proliferation of different powertrain configurations may

  2. DEVELOPMENT OF THE RISK-BASED MAINTENANCE OPTIMIZATION SYSTEM FOR FOSSIL POWER PLANTS

    Institute of Scientific and Technical Information of China (English)

    D.Watanabe; Y.Chuman; N.Nishimura; H.Matsumoto; K.Tominaga; F.Sakata; T.Kuroishi

    2004-01-01

    Cost reduction in electric power generation is a major management concern, and it is therefore necessary to reduce maintenance expenses while upholding plant reliability.A maintenance optimization system "FREEDOM", which uses RBM technique, DCF (discounted cash flow) and NPV (net present value) calculation functions, has been newly developed. This system probabilistically evaluates the lifetime of boiler and turbine and quantitatively calculates the risk defined as the cumulative probability of failure multiplied by the consequence of failure. Economically optimized timing of inspection and alternative countermeasure such as repair and replacement are then recommended. This system has already been applied to seven plants in Japan, and its effectiveness has been confirmed.

  3. Performance assessment and optimization of a combined heat and power system based on compressed air energy storage system and humid air turbine cycle

    International Nuclear Information System (INIS)

    Highlights: • A combined heat and power system based on CAES and HAT is proposed. • The design and modeling of the CAES–HAT based CHP system are laid out. • The performance assessment of the proposed system is carried out. • The system optimization is conducted to decide the maximum conditions. - Abstract: Renewable energy based power sources have grown rapidly in the past few years owing to the dual constraint of climate change and pollution control. Compressed air energy storage (CAES), as a large-scale energy storage system (ESS) technology, has huge potential to manage the intermittent renewable energy based power sources effectively. However, the compression heat generated during charge and waste heat carried in turbine exhaust during discharge are not fully recuperated in current stage. A combined heat and power (CHP) system consisting of a CAES system and a humid air turbine (HAT) system is proposed to utilize the both types of heat energy. The proposed system can boost the power output, enhance performance and improve efficiency through a simultaneous supply of power and heat. The thermodynamic analysis shows that the expansion train power can be improved about 26% compared with the conventional CAES system. The parametric analysis reveals that the exergy efficiency increases with the turbine inlet temperature (TIT) of high pressure turbine (HPT) and inlet pressure of low pressure turbine (LPT), but decreases with the TIT of LPT, L/G ratio and dry air inlet temperature of saturator. Meanwhile, the system optimization is carried out via particle swarm optimization (PSO) to determine the maximum power and exergy efficiency conditions

  4. Power consumption reduction in a SDR based wireless communication system using partial reconfigurable FPGA

    Directory of Open Access Journals (Sweden)

    Neenu Joseph

    2012-04-01

    Full Text Available The increase in the consumer demand and the exponential growth for wireless systems, which enables consumer to communicate in any place by means of information, has in turn led to the emergence of many portable wireless communication products. The present research works primarily targets to integrate as much as signal processing applications in a single portable device. Since integration through software applications compromises system speed, integration through hardware will be the better compliment. Software Defined Radio (SDR Technology yields to achieve this small form factor system while keeping power consumption under the limit. SDR enables soft changeable system functionality, such as receiver demodulation technique .In this implementation two type modulation techniques are used, ASK and FSK. The flexibility of changing the receiver functionality in run time is usually attained by FPGA. However, using a complete FPGA for reconfiguration of a particular functionality is not an efficient method in terms of power consumption and switching time. We proposed a SDR architecture using a recent advancement in FPGAs, called Partial Reconfiguration (PR. PR helps to change certain portion of FPGA, while the rest keeps functioning. It also reduces the total hardware usage and hence the power. The different demodulation technique and other signal processing application from an external memory unit can be loaded into FPGA PR modules while the other parts of FPGA doing a constant data processing.

  5. Study on Network Remote Controlling Huge-Power Chopping Cascade Speed Regulation System Based on State-Space Averaging Model

    Directory of Open Access Journals (Sweden)

    Zhuo Zhang

    2014-07-01

    Full Text Available This paper deals with the modeling of DC-DC boost chopping circuit in a huge-power chopping cascade speed regulation system while the motor power level is over 1 megawatt. The model involves the Insulated Gate Bipolar Translator(IGBT & Free-Wheel Diode(FWD based on a state-space averaging method. It solves the problems of thedesigning of a control system in the chopping cascade speed regulation system when the controlling motor has a huge power. The system can be remote controlled through the industrial field network, and it has a good interface of human-computer interaction.The experiments show that the dual closed-loop control system is reliable and stable, it also has the better steady-state and dynamic characteristics and higher power factor compared with traditional cascade speed regulation systems. Based on this dual closed-loop control system, several devices with remarkable energy-saving effect have been running very well in the industrial sites. 

  6. Power system low frequency oscillation monitoring and analysis based on multi-signal online identification

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The advance in the wide-area measurement system (WAMS) is driving the power system to the trend of wide-area monitoring and control.The Prony method is usually used for low frequency oscillation online identification.However,the identified amplitude and phase information is not sufficiently used.In this paper,the amplitude is adopted to detect the occurrence of the oscillation and to obtain the mode observability of the sites.The phase is adopted to identify the oscillation generator grouping and to obtain the mode shapes.The time varying characteristics of low frequency oscillations are studied.The behaviors and the characters of low frequency oscillations are displayed by dynamic visual techniques.Demonstrations on the "11.9" low frequency oscillation of the Guizhou Power Grid substantiate the feasibility and the validation of the proposed methods.

  7. Performance based design of structures, systems and equipment in Indian nuclear power plants

    International Nuclear Information System (INIS)

    Nuclear power plants in India have been designed for earthquake resistance by the methods of analysis and testing. Many of the electrical and instrumentation equipment have been tested on shake tables available in India. The performance of the civil structures, piping systems, cable trays, ducting and mechanical, electrical, instrumentation and control equipment in industries around Koyna (1967, 6.5 M), Bhuj (2001, 7.6 M) and Muzaffarabad (2005, 7.6 M) which have witnessed the earthquake is also available

  8. CFD Simulations of a Regenerative Process for Carbon Dioxide Capture in Advanced Gasification Based Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Arastoopour, Hamid [Illinois Inst. of Technology, Chicago, IL (United States); Abbasian, Javad [Illinois Inst. of Technology, Chicago, IL (United States)

    2014-07-31

    the method of moments, called Finite size domain Complete set of trial functions Method Of Moments (FCMOM) was used to solve the population balance equations. The PBE model was implemented in a commercial CFD code, Ansys Fluent 13.0. The code was used to test the model in some simple cases and the results were verified against available analytical solution in the literature. Furthermore, the code was used to simulate CO2 capture in a packed-bed and the results were in excellent agreement with the experimental data obtained in the packed bed. The National Energy Laboratory (NETL) Carbon Capture Unit (C2U) design was used in simulate of the hydrodynamics of the cold flow gas/solid system (Clark et al.58). The results indicate that the pressure drop predicted by the model is in good agreement with the experimental data. Furthermore, the model was shown to be able to predict chugging behavior, which was observed during the experiment. The model was used as a base-case for simulations of reactive flow at elevated pressure and temperatures. The results indicate that by controlling the solid circulation rate, up to 70% CO2 removal can be achieved and that the solid hold up in the riser is one of the main factors controlling the extent of CO2 removal. The CFD/PBE simulation model indicates that by using a simulated syngas with a composition of 20% CO2, 20% H2O, 30% CO, and 30% H2, the composition (wet basis) in the reactor outlet corresponded to about 60% CO2 capture with and exit gas containing 65% H2. A preliminary base-case-design was developed for a regenerative MgO-based pre-combustion carbon capture process for a 500 MW IGCC power plant. To minimize the external energy requirement, an extensive heat integration network was developed in Aspen/HYSYS® to produce the steam required in the regenerator and heat integration. In this process, liquid CO2 produced at 50 atm can easily be pumped and sequestered or stored. The preliminary economic analyses indicate that the

  9. A novel power generation system based on moderate conversion of chemical energy of coal and natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Wei Han; Hongguang Jin; Rumou Lin [Chinese Academy of Sciences, Beijing (China). Institute of Engineering Thermophysics

    2011-01-15

    This paper proposes a novel power generation system that implements mutually beneficial use of natural gas and coal. In conventional power plants fossil fuels are usually directly burned with air to convert the chemical energy to thermal energy for power generation. In combustion processes, about 30% of exergy of fuels is destructed, and the decrease in the irreversibility of combustion processes has large potential to improve the performance of power plants. The new system attempts to use chemical exergy of fuels before combustion through coordinated use of coal and natural gas. First approximate 60% of coal is gasified in a gasifier with air and steam as oxidant, then, the unconverted residuals (char) and natural gas are utilized synthetically based on the method of char-fired reforming to generate syngas, in which the combustion of char will drive the methane/steam-reforming reaction. The fuel gas from the partial gasification of coal and syngas from char-fired reforming are mixed together and fed into a combined cycle for power generation. As a result, the overall thermal efficiency of the new system is about 51.5% based on the current turbine technologies and the net thermal efficiency of coal to electricity of the new system can reach near 48.6%. The results obtained here may provide a new way of using coal and natural gas more efficiently and economically. 28 refs., 6 figs., 6 tabs., 1 app.

  10. TEG BASED POWER SYSTEM for OPERATION of HEALTH MONITORING SERVER in INDUSTRIES

    Directory of Open Access Journals (Sweden)

    P.S.Raghavendran

    2014-01-01

    Full Text Available In Hazardous environment industries where the emission of toxic gases and effluents will have an impact on the health of the operators, the recording of health parameters of individual operators is very important. In such situation the health monitoring of operators are being monitored and processed centrally by a server and this can be powered by a system of batteries which can be operated from TEG to ensure reliability and to utilize the exhaust heat energy of industries for better performance. This paper describes the Thermo electric generator with battery that supports medical server. The thermoelectric generator converts heat energy into electrical energy. Mathematical model of thermoelectric generator was developed in MATLAB SIMULINK. This exhibits different voltage and current for various temperature differences. The proposed system uses maximum power point tracking algorithm to obtain the maximum power from the thermoelectric generator. This algorithm is developed in embedded MATLAB controller, which gives the firing angle to the DC-DC Boost converter for various temperature differences. This will increase the efficiency of the system.

  11. A Novel Maximum Power Point Tracking Algorithm Based on Glowworm Swarm Optimization for Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Wenhui Hou

    2016-01-01

    Full Text Available In order to extract the maximum power from PV system, the maximum power point tracking (MPPT technology has always been applied in PV system. At present, various MPPT control methods have been presented. The perturb and observe (P&O and conductance increment methods are the most popular and widely used under the constant irradiance. However, these methods exhibit fluctuations among the maximum power point (MPP. In addition, the changes of the environmental parameters, such as cloud cover, plant shelter, and the building block, will lead to the radiation change and then have a direct effect on the location of MPP. In this paper, a feasible MPPT method is proposed to adapt to the variation of the irradiance. This work applies the glowworm swarm optimization (GSO algorithm to determine the optimal value of a reference voltage in the PV system. The performance of the proposed GSO algorithm is evaluated by comparing it with the conventional P&O method in terms of tracking speed and accuracy by utilizing MATLAB/SIMULINK. The simulation results demonstrate that the tracking capability of the GSO algorithm is superior to that of the traditional P&O algorithm, particularly under low radiance and sudden mutation irradiance conditions.

  12. Towards a Cellular Automata Based Network Intrusion Detection System with Power Level Metric in Wireless Adhoc Networks (IDFADNWCA)

    OpenAIRE

    Sree, Pokkuluri Kiran; Babu, Inampudi Ramesh

    2014-01-01

    Adhoc wireless network with their changing topology and distributed nature are more prone to intruders. The efficiency of an Intrusion detection system in the case of an adhoc network is not only determined by its dynamicity in monitoring but also in its flexibility in utilizing the available power in each of its nodes. In this paper we propose a hybrid intrusion detection system, based on a power level metric for potential adhoc hosts, which is used to determine the duration for which a part...

  13. Area-Based COI-Referred Rotor Angle Index for Transient Stability Assessment and Control of Power Systems

    OpenAIRE

    Noor Izzri Abdul Wahab; Azah Mohamed

    2012-01-01

    This paper describes an index for judging the severity of transient events of power systems in simulation. The proposed transient stability index, known as the area-based COI-referred rotor angle index, is developed by considering the fact that a large-sized power system is divided into several areas according to the coherency of generators in a particular area. It can be assumed that an equivalent single large machine can represent all the generators in that area. Thus, the assessment of rot...

  14. ANFIS-based modelling for photovoltaic power supply system: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Mellit, Adel [Faculty of Sciences and Technology, Department of Electronics, LAMEL, Jijel University, Ouled-Aissa, P.O. Box 98, Jijel 18000 (Algeria); Kalogirou, Soteris A. [Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, P.O. Box 50329, Limassol 3603 (Cyprus)

    2011-01-15

    Due to the various seasonal, monthly and daily changes in meteorological data, it is relatively difficult to find a suitable model for Photovoltaic power supply (PVPS) system. This paper deals with the modelling and simulation of a PVPS system using an Adaptive Neuro-Fuzzy Inference Scheme (ANFIS) and the proposition of a new expert configuration PVPS system. For the modelling of the PVPS system, it is required to find suitable models for its different components (ANFIS PV generator, ANFIS battery and ANFIS regulator) that could give satisfactory results under variable climatic conditions in order to test its performance and reliability. A database of measured climate data (global radiation, temperature and humidity) and electrical data (photovoltaic, battery and regulator voltage and current) of a PVPS system installed in Tahifet (south of Algeria) has been recorded for the period from 1992 to 1997. These data have been used for the modelling and simulation of the PVPS system. The results indicated that the reliability and the accuracy of the simulated system are excellent and the correlation coefficient between measured values and those estimated by the ANFIS gave a good prediction accuracy of 98%. Additionally, test results show that the ANFIS performed better than the Artificial Neural Network (ANN), which has also being tried to model the system. In addition, a new configuration of an expert PVPS system is proposed in this work. The predicted electrical data by the ANFIS model can be used for several applications in PV systems. (author)

  15. Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    Southern Company Services

    2009-01-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.

  16. A review of solar energy based heat and power generation systems

    DEFF Research Database (Denmark)

    Modi, Anish; Bühler, Fabian; Andreasen, Jesper Graa;

    2017-01-01

    The utilization of solar energy based technologies has attracted increased interest in recent times in order to satisfy the various energy demands of our society. This paper presents a thorough review of the open literature on solar energy based heat and power plants. In order to limit the scope......) a biomass burner, and (5) an organic Rankine cycle. The various cases are compared on the basis of economic profitability and environmental performance. The results from the case studies indicate that it is economically and environmentally beneficial to invest in both small and large capacity solar...

  17. Digital arc welding power supply based on real-time operating system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS-Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS-Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments,the ARM and the micro C/OS-Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder.

  18. Permanent Magnet Synchronous Generator Driven Wind Energy Conversion System Based on Parallel Active Power Filter

    Directory of Open Access Journals (Sweden)

    FERDI Brahim

    2014-05-01

    Full Text Available This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS. The proposed WECS is formed by permanent magnet synchronous generator (PMSG wind turbine system connected to the grid through parallel active power filter (PAPF. PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC, compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. To demonstrate the feasibility and the performance of the proposed control scheme, simulation of this wind system has been realized using MATLAB/SIMULINK software. Simulation results show the accuracy and validity of the proposed control scheme for the PMSGPAPF system.

  19. Analysis of combined cooling, heating, and power systems based on source primary energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    Fumo, Nelson; Chamra, Louay M. [Department of Mechanical Engineering, Mississippi State University, 210 Carpenter Engineering Building, P.O. Box ME, Mississippi State, MS 39762-5925 (United States)

    2010-06-15

    Combined cooling, heating, and power (CCHP) is a cogeneration technology that integrates an absorption chiller to produce cooling, which is sometimes referred to as trigeneration. For building applications, CCHP systems have the advantage to maintain high overall energy efficiency throughout the year. Design and operation of CCHP systems must consider the type and quality of the energy being consumed. Type and magnitude of the on-site energy consumed by a building having separated heating and cooling systems is different than a building having CCHP. Therefore, building energy consumption must be compared using the same reference which is usually the primary energy measured at the source. Site-to-source energy conversion factors can be used to estimate the equivalent source energy from site energy consumption. However, building energy consumption depends on multiple parameters. In this study, mathematical relations are derived to define conditions a CCHP system should operate in order to guarantee primary energy savings. (author)

  20. A method of knowledge base verification and validation for nuclear power plants expert systems

    International Nuclear Information System (INIS)

    The adoption of expert systems mainly as operator supporting systems is becoming increasingly popular as the control algorithms of system become more and more sophisticated and complicated. As a result of this popularity, a large number of expert systems are developed. The nature of expert systems, however, requires that they be verified and validated carefully and that detailed methodologies for their development be devised. Therefore, it is widely noted that assuring the reliability of expert systems is very important, especially in nuclear industry, and it is also recognized that the process of verification and validation is an essential part of reliability assurance for these systems. Research and practices have produced numerous methods for expert system verification and validation (V and V) that suggest traditional software and system approaches to V and V. However, many approaches and methods for expert system V and V are partial, unreliable, and not uniform. The purpose of this paper is to present a new approach to expert system V and V, based on Petri nets, providing a uniform model. We devise and suggest an automated tool, called COKEP (Checker Of Knowledge base using Extended Petri net), for checking incorrectness, inconsistency, and incompleteness in a knowledge base. We also suggest heuristic analysis for validation process to show that the reasoning path is correct

  1. Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

    Science.gov (United States)

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. PMID:26121032

  2. Technical Study of a Standalone Photovoltaic–Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia

    Science.gov (United States)

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. PMID:26121032

  3. Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

    Science.gov (United States)

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.

  4. Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

    Directory of Open Access Journals (Sweden)

    Nahidul Hoque Samrat

    Full Text Available Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.

  5. Harmonic Injection-Based Power Fluctuation Control of Three-Phase PV Systems under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Nian-Cheng Zhou

    2015-02-01

    Full Text Available Unbalanced voltage will inevitably cause power and DC voltage fluctuations in a three-phase PV system. The deterioration of power quality will do great harm to the PV panels and the loads, so it is necessary to suppress the power fluctuations. This paper further explores the coefficients control strategy of PV converters under unbalanced voltage conditions, aiming to suppress power fluctuations by controlling the injection of some specific orders of current harmonics into the grid. In order to achieve this, the current reference of the PV inverter has been changed by bringing in two control coefficients, and the expression of each order of the current harmonics has been deduced. Based on the standards of PV systems, the regions from which the coefficients can be selected are determined. Then, by tuning these coefficients in the feasible regions, the output parameters (power fluctuation, current THD and odd harmonics can be controlled precisely. The model of this method is built and simulated in PSCAD/EMTDC, and as a result, it is shown that the power fluctuations can be restricted according to different power quality requirements.

  6. Design and fabrication of vibration based energy harvester using microelectromechanical system piezoelectric cantilever for low power applications.

    Science.gov (United States)

    Kim, Moonkeun; Lee, Sang-Kyun; Yang, Yil Suk; Jeong, Jaehwa; Min, Nam Ki; Kwon, Kwang-Ho

    2013-12-01

    We fabricated dual-beam cantilevers on the microelectromechanical system (MEMS) scale with an integrated Si proof mass. A Pb(Zr,Ti)O3 (PZT) cantilever was designed as a mechanical vibration energy-harvesting system for low power applications. The resonant frequency of the multilayer composition cantilevers were simulated using the finite element method (FEM) with parametric analysis carried out in the design process. According to simulations, the resonant frequency, voltage, and average power of a dual-beam cantilever was 69.1 Hz, 113.9 mV, and 0.303 microW, respectively, at optimal resistance and 0.5 g (gravitational acceleration, m/s2). Based on these data, we subsequently fabricated cantilever devices using dual-beam cantilevers. The harvested power density of the dual-beam cantilever compared favorably with the simulation. Experiments revealed the resonant frequency, voltage, and average power density to be 78.7 Hz, 118.5 mV, and 0.34 microW, respectively. The error between the measured and simulated results was about 10%. The maximum average power and power density of the fabricated dual-beam cantilever at 1 g were 0.803 microW and 1322.80 microW cm(-3), respectively. Furthermore, the possibility of a MEMS-scale power source for energy conversion experiments was also tested. PMID:24266167

  7. Wind power in modern power systems

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    In recent years, wind power is experiencing a rapid growth, and large-scale wind turbines/wind farms have been developed and connected to power systems. However, the traditional power system generation units are centralized located synchronous generators with different characteristics compared...... with wind turbines. This paper presents an overview of the issues about integrating large-scale wind power plants into modern power systems. Firstly, grid codes are introduced. Then, the main technical problems and challenges are presented. Finally, some possible technical solutions are discussed....

  8. A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: CEDINFO

    Energy Technology Data Exchange (ETDEWEB)

    Nuriye Peker Say; Muzaffer Yucel; Mehmet Yilmazer [Cukurova University, Adana (Turkey). Department of Landscape Architecture

    2007-12-15

    Environmental impact assessment (EIA) is a tool to enable decision makers to account for the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data. In this study, a knowledge-based software CEDINFO developed by authors was introduced. CEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power stations, hydroelectric power stations, nuclear power stations) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. CEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations. 23 refs., 5 figs., 2 tabs.

  9. Power Allocation Algorithm for IDMA-based Multi-Beam Satellite Communication Systems

    Directory of Open Access Journals (Sweden)

    Gongliang Liu

    2012-08-01

    Full Text Available Rain attenuation is one of the most dominant impairment factors that degrade the performance of satellite communications at Ka band and above. In order to solve the technical bottlenecks in the existing Ka-band satellite communication schemes, the authors has introduced the emerging Interleave Division Multiple Access (IDMA technology into multi-beam satellite communication systems, and consequently, a novel power allocation algorithm is proposed for the emerging and promising system in this paper. The main goal of the proposed scheme is to provide sufficient transmission quality to as many mobiles as possible, even for the users suffering heavy rain attenuation. Analysis and simulation results show that compared to the traditional power allocation schemes, the proposed scheme can guarantee high power efficiency even in heavy rain attenuation conditions, illustrating the high efficiency of the Chip-by-Chip (CBC Multi-user Detection (MUD technique in IDMA. Furthermore, in virtue of the Signal to Interference plus Noise Ratio (SINR evolution technique, the proposed scheme can make accurate estimation of available resource on considering the effect of MUD, leading to low outage probability.

  10. Automatic generation control of multi-area power systems with diverse energy sources using Teaching Learning Based Optimization algorithm

    Directory of Open Access Journals (Sweden)

    Rabindra Kumar Sahu

    2016-03-01

    Full Text Available This paper presents the design and analysis of Proportional-Integral-Double Derivative (PIDD controller for Automatic Generation Control (AGC of multi-area power systems with diverse energy sources using Teaching Learning Based Optimization (TLBO algorithm. At first, a two-area reheat thermal power system with appropriate Generation Rate Constraint (GRC is considered. The design problem is formulated as an optimization problem and TLBO is employed to optimize the parameters of the PIDD controller. The superiority of the proposed TLBO based PIDD controller has been demonstrated by comparing the results with recently published optimization technique such as hybrid Firefly Algorithm and Pattern Search (hFA-PS, Firefly Algorithm (FA, Bacteria Foraging Optimization Algorithm (BFOA, Genetic Algorithm (GA and conventional Ziegler Nichols (ZN for the same interconnected power system. Also, the proposed approach has been extended to two-area power system with diverse sources of generation like thermal, hydro, wind and diesel units. The system model includes boiler dynamics, GRC and Governor Dead Band (GDB non-linearity. It is observed from simulation results that the performance of the proposed approach provides better dynamic responses by comparing the results with recently published in the literature. Further, the study is extended to a three unequal-area thermal power system with different controllers in each area and the results are compared with published FA optimized PID controller for the same system under study. Finally, sensitivity analysis is performed by varying the system parameters and operating load conditions in the range of ±25% from their nominal values to test the robustness.

  11. Home grown power plants - the case for wood-based energy systems in Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Kapadia, K. [University of California, Berkeley (United States). Energy and Resources Group

    2002-12-01

    The article is essentially an overview of the case for wood-based energy systems for Sri Lanka. Such systems are attractive in terms of being local, low-cost, and sustainable. However, development of such systems is hampered by insufficient political support, and concern over deforestation and waste in the context of the proposed large-scale biomass gasification. The article discusses benefits of the system, how it works, costs and economics and biomass potential. Other renewable energy systems discussed include solar, wind and hydro.

  12. Model-based Diagnosis of a Satellite Electrical Power System with RODON

    OpenAIRE

    Isaksson, Olle

    2009-01-01

    As space exploration vehicles travel deeper into space, their distance to earth increases.The increased communication delays and ground personnel costs motivatea migration of the vehicle health management into space. A way to achieve thisis to use a diagnosis system. A diagnosis system uses sensor readings to automaticallydetect faults and possibly locate the cause of it. The diagnosis system usedin this thesis is a model-based reasoning tool called RODON developed by UptimeSolutions AB. RODO...

  13. System efficiency of a tap transformer based grid connection topology applied on a direct driven generator for wind power.

    Science.gov (United States)

    Apelfröjd, Senad; Eriksson, Sandra

    2014-01-01

    Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed.

  14. System Efficiency of a Tap Transformer Based Grid Connection Topology Applied on a Direct Driven Generator for Wind Power

    Directory of Open Access Journals (Sweden)

    Senad Apelfröjd

    2014-01-01

    Full Text Available Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed.

  15. System efficiency of a tap transformer based grid connection topology applied on a direct driven generator for wind power.

    Science.gov (United States)

    Apelfröjd, Senad; Eriksson, Sandra

    2014-01-01

    Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed. PMID:25258733

  16. Discussion of Docker Based on Power Systems%基于Power Systems的Docker发展研究

    Institute of Scientific and Technical Information of China (English)

    张军利

    2015-01-01

    文章从由来、特点、优势等方面对Docker进行全面介绍,通过对部署在不同Hypervisor上的结果进行比较分析,证明Docker部署在Power Systems上的可行性和优势性,并预测Power Systems有望借Docker实现对X86的赶超.

  17. Current status of fuel cell based combined heat and power systems for residential sector

    Science.gov (United States)

    Ellamla, Harikishan R.; Staffell, Iain; Bujlo, Piotr; Pollet, Bruno G.; Pasupathi, Sivakumar

    2015-10-01

    Combined Heat and Power (CHP) is the sequential or simultaneous generation of multiple forms of useful energy, usually electrical and thermal, in a single and integrated system. Implementing CHP systems in the current energy sector may solve energy shortages, climate change and energy conservation issues. This review paper is divided into six sections: the first part defines and classifies the types of fuel cell used in CHP systems; the second part discusses the current status of fuel cell CHP (FC-CHP) around the world and highlights the benefits and drawbacks of CHP systems; the third part focuses on techniques for modelling CHP systems. The fourth section gives a thorough comparison and discussion of the two main fuel cell technologies used in FC-CHP (PEMFC and SOFC), characterising their technical performance and recent developments from the major manufacturers. The fifth section describes all the main components of FC-CHP systems and explains the issues connected with their practical application. The last part summarises the above, and reflects on micro FC-CHP system technology and its future prospects.

  18. A knowledge based system (ESR) assisted assessment of the remaining life time of power plant components predicted by standards

    International Nuclear Information System (INIS)

    The lecture reports on the development of a knowledge based expert system by the MPA, Stuttgart, for assessment of the remaining life time of power plant components. The MPA's programme receivers financial and expert knowledge support from seven European power plant operators, who cooperate in the programme in order to bring together the available practical experience, and to process the information to a pool that can be 'trapped' for pin-pointed use. In addition, the system under development incorporates technical codes and standards, regulations and case studies; it offers the possibility of performing calculations and retrieving or storing data. The (expert) system is intended as a database for assessment of pressurized power plant components operated at elevated temperatures, and is to serve design engineers, operating and monitoring engineers. It is implemented on a PC. The requirements to be fulfilled by the system as well as its functions and applications have been defined to a large extent by the power plant operators. The lecture explains the system design, applications and functioning modes, illustrated by some examples showing the pin-pointed retrievability of stored knowledge, and the user friendliness of the system. (orig.)

  19. On Maximal Power Point of Photovoltaic Power Generation System

    OpenAIRE

    Setiawan, Eko; Hodaka, Ichijo

    2012-01-01

    Numerous studies have been developed to get the maximum power of photovoltaic (PV). Most of the studies assume that the maximum power will be reached when the PV works at the maximum power point (MPP). Since the real target is maximizing power at the load-side, that assumption should be clarified. This paper presents an analysis of photovoltaic power generation system. Some numerical value is applied to realize the value. Based on the analysis, difference value of photovoltaic MPP and load MP...

  20. Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power

    Directory of Open Access Journals (Sweden)

    J. W. Kaiser

    2011-07-01

    Full Text Available The Global Fire Assimilation System (GFASv1.0 calculates biomass burning emissions by assimilating Fire Radiative Power (FRP observations from the MODIS instruments onboard the Terra and Aqua satellites. It corrects for gaps in the observations, which are mostly due to cloud cover, and filters spurious FRP observations of volcanoes, gas flares and other industrial activity. The combustion rate is subsequently calculated with land cover-specific conversion factors. Emission factors for 40 gas-phase and aerosol trace species have been compiled from a literature survey. The corresponding daily emissions have been calculated on a global 0.5° × 0.5° grid from 2003 to the present. General consistency with the Global Fire Emission Database version 3.1 (GFED3.1 within its accuracy is achieved while maintaining the advantages of an FRP-based approach: GFASv1.0 makes use of the quantitative information on the combustion rate that is contained in the observations, and it detects fires in real time at high spatial and temporal resolution. GFASv1.0 indicates omission errors in GFED3.1 due to undetected small fires. It also exhibits slightly longer fire seasons in South America and North Africa and a slightly shorter fire season in Southeast Asia. GFASv1.0 has already been used for atmospheric reactive gas simulations in an independent study, which found good agreement with atmospheric observations. We have performed simulations of the atmospheric aerosol distribution with and without the assimilation of MODIS aerosol optical depth (AOD. They indicate that the emissions of particulate matter need to be boosted with a factor of 2–4 to reproduce the global distribution of organic matter and black carbon. This discrepancy is also evident in the comparison of previously published top-down and bottom-up estimates. For the time being, a global enhancement of the particulate matter emissions by 3.4 is recommended. Validation with independent AOD and PM10

  1. A method of knowledge base verification for nuclear power plant expert systems using extended Petri Nets

    International Nuclear Information System (INIS)

    The adoption of expert systems mainly as operator supporting systems is becoming increasingly popular as the control algorithms of system become more and more sophisticated and complicated. The verification phase of knowledge base is an important part for developing reliable expert systems, especially in nuclear industry. Although several strategies or tools have been developed to perform potential error checking, they often neglect the reliability of verification methods. Because a Petri net provides a uniform mathematical formalization of knowledge base, it has been employed for knowledge base verification. In this work, we devise and suggest an automated tool, called COKEP(Checker of Knowledge base using Extended Petri net), for detecting incorrectness, inconsistency, and incompleteness in a knowledge base. The scope of the verification problem is expended to chained errors, unlike previous studies that assume error incidence to be limited to rule pairs only. In addition, we consider certainty factor in checking, because most of knowledge bases have certainly factors. 8 refs,. 2 figs,. 4 tabs. (author)

  2. A power conversion system for PMSG-based WECS operating with fully-controlled current-source converters

    Institute of Scientific and Technical Information of China (English)

    Jian-yu BAO; Wei-bing BAO; Yu-ling LI

    2014-01-01

    We propose a new power conversion system for a permanent magnet synchronous generator (PMSG) based grid-connected wind energy conversion system (WECS) operating with fully-controlled back-to-back current-source converters. On the generator side, two independent current-source rectifiers (CSRs) with space-vector pulse width modulation (SVPWM) are employed to regulate and stabilize DC-link currents. Between DC-link and the electrical grid, a direct-type three-phase five-level current-source inverter (CSI) is inserted as a buffer to regulate real and reactive power fed to the grid and thus adjusts the grid side power-factor. We also present a current-based maximum power point tracking (MPPT) scheme, which helps the generator extract the maximum power through closed-loop regulation of the generator speed. By applying the multilevel modulation and control strategies to the grid-side five-level CSI, a multilevel output current waveform with less distortion is produced, and the bulk requirement of the output capacitor filter to eliminate the harmonic current is reduced. All the proposed concepts are verified by simulation models built in a PSIM environment.

  3. Stochastic Dynamic Programming Applied to Hydrothermal Power Systems Operation Planning Based on the Convex Hull Algorithm

    Directory of Open Access Journals (Sweden)

    Bruno H. Dias

    2010-01-01

    Full Text Available This paper presents a new approach for the expected cost-to-go functions modeling used in the stochastic dynamic programming (SDP algorithm. The SDP technique is applied to the long-term operation planning of electrical power systems. Using state space discretization, the Convex Hull algorithm is used for constructing a series of hyperplanes that composes a convex set. These planes represent a piecewise linear approximation for the expected cost-to-go functions. The mean operational costs for using the proposed methodology were compared with those from the deterministic dual dynamic problem in a case study, considering a single inflow scenario. This sensitivity analysis shows the convergence of both methods and is used to determine the minimum discretization level. Additionally, the applicability of the proposed methodology for two hydroplants in a cascade is demonstrated. With proper adaptations, this work can be extended to a complete hydrothermal system.

  4. Evaluation of reliability of on-site A.C. power systems based on maintenance records

    International Nuclear Information System (INIS)

    To the end of ascertain in what extent the evaluation of reliability of emergency diesel generators (D.G.) can be improved by means of a deeper knowledge of their operating history a study has been carried-out on 21 D.G. sets: 4 D.G. of the Caorso nuclear plant (BWR, 870 MWe) and 17 D.G. in service at 6 steam-electric fossil-fuelled plants. The major points of interest resulting from this study are: 1) reliability assessments of A.C. on-site power Systems, made on the basis of outcomes of surveillance tests, may lead to results which overestimate the real performance. 2) the unreliability of a redundant System of stand-by components is determined in large extent by unavailabilities due to scheduled and unscheduled maintenance, latent failures, tests. (authors)

  5. Optimizing operation of a solar-aided coal-fired power system based on the solar contribution evaluation method

    International Nuclear Information System (INIS)

    Highlights: • The solar contribution of the solar-aided coal-fired power plant was calculated. • Adjusting heat transfer fluid flow rate to improve the performance of the system. • The generation revenue function was proposed to evaluate the system. - Abstract: A solar-aided coal-fired power system (SACFPS) model with five load conditions (100%, 85%, 75%, 50%, and 40%) was built based on thermodynamic and thermoeconomic theories. SACFPS is a combination of a parabolic trough solar power system and a 660 MW coal-fired generation plant. The solar contribution evaluation method was introduced into the model to calculate the generation share of the solar power system. Results show that solar contribution decreases after an initial increase as effective solar normal irradiation increases. Optimization strategies, adjusting heat transfer fluid flow rate, have been proposed to maintain solar contribution at a high level. Thus, SACFPS with five load conditions has been optimized. This study also establishes a generation revenue function to evaluate the economics of SACFPS. Income generation of SACFPS after optimization is significantly higher than that without optimization

  6. Optimal Power Allocation Algorithm for Radar Network Systems Based on Low Probability of Intercept Optimization(in English

    Directory of Open Access Journals (Sweden)

    Shi Chen-guang

    2014-08-01

    Full Text Available A novel optimal power allocation algorithm for radar network systems is proposed for Low Probability of Intercept (LPI technology in modern electronic warfare. The algorithm is based on the LPI optimization. First, the Schleher intercept factor for a radar network is derived, and then the Schleher intercept factor is minimized by optimizing the transmission power allocation among netted radars in the network to guarantee target-tracking performance. Furthermore, the Nonlinear Programming Genetic Algorithm (NPGA is used to solve the resulting nonconvex, nonlinear, and constrained optimization problem. Numerical simulation results show the effectiveness of the proposed algorithm.

  7. Investigation of power values of PV rooftop systems based on heat gain reduction

    Science.gov (United States)

    Chenvidhya, Tanokkorn; Seapan, Manit; Parinya, Panom; Wiengmoon, Buntoon; Chenvidhya, Dhirayut; Songprakorp, Roongrojana; Limsakul, Chamnan; Sangpongsanont, Yaowanee; Tannil, Nittaya

    2015-09-01

    PV rooftop system can generally be installed to produce electricity for the domestic house, office, small enterprise as well as factory. Such a system has direct useful for reducing peak load, meanwhile it also provides shaded area on the roof and hence the heat gain into the building is reduced. This study aims to investigate the shading effect on reduction of heat transfer into the building. The 49 kWp of PV rooftop system has been installed on the deck of the office building located in the middle of Thailand where the latitude of 14 ° above the equator. The estimation of heat gain into the building due to the solar irradiation throughout a day for one year has been carried out, before and after the installation of the PV rooftop system. Then the Newton's law of cooling is applied to calculate the heat gain. The calculation and the measurement of the heat reduction are compared. Finally, the indirect benefit of the PV rooftop system installed is evaluated in terms of power value.

  8. Application of Q-learning with temperature variation for bidding strategies in market based power systems

    International Nuclear Information System (INIS)

    The electric power industry is confronted with restructuring in which the operation scheduling is going to be decided based on a competitive market. In this new arrangement, bidding strategy has become a major issue. Participants in this deregulated energy market place may be able to compete better by choosing a suitable bidding strategy for trading electricity. Different classical methods for decision making in the uncertain environment of the market can be applied to select a suitable strategy. Most of these methods, such as game theory, that insure reaching the best solution for all market participants, require a lot of information about the other market players and the market. However, in the real market place only a little information, such as the spot price, is available for all participants. In this paper, a modified reinforcement learning based on temperature variation has been first proposed and then applied to determine the optimal strategy for a power supplier in the electricity market. A Pool-Co model has been considered here, and the simulation results are shown to be the same as those of standard game theory. Adaptation of the method in the presence of parameter variation has been verified as well. The main advantage of the proposed method is that no information about other participants is required. Furthermore, our investigation shows that even if all participants use this method, they will stay in Nash equilibrium. (author)

  9. Application of Q-learning with temperature variation for bidding strategies in market based power systems

    International Nuclear Information System (INIS)

    The electric power industry is confronted with restructuring in which the operation scheduling is going to be decided based on a competitive market. In this new arrangement, bidding strategy has become a major issue. Participants in this deregulated energy market place may be able to compete better by choosing a suitable bidding strategy for trading electricity. Different classical methods for decision making in the uncertain environment of the market can be applied to select a suitable strategy. Most of these methods, such as game theory, that insure reaching the best solution for all market participants, require a lot of information about the other market players and the market. However, in the real market place only a little information, such as the spot price, is available for all participants. In this paper, a modified reinforcement learning based on temperature variation has been first proposed and then applied to determine the optimal strategy for a power supplier in the electricity market. A Pool-Co model has been considered here, and the simulation results are shown to be the same as those of standard game theory. Adaptation of the method in the presence of parameter variation has been verified as well. The main advantage of the proposed method is that no information about other participants is required. Furthermore, our investigation shows that even if all participants use this method, they will stay in Nash equilibrium

  10. Performance study on three-stage power system of compressed air vehicle based on single-screw expander

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each style.Research results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,respectively.Results also showed that heating up inlet air or increasing the expander efficiency might improve the power performance.The output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"style.The new system showed good structure and power performances.

  11. Cost-optimal power system extension under flow-based market coupling and high shares of photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Hagspiel, Simeon; Jaegemann, Cosima; Lindenberger, Dietmar [Koeln Univ. (Germany). Inst. of Energy Economics; Cherevatskiy, Stanislav; Troester, Eckehard; Brown, Tom [Energynautics GmbH, Langen (Germany)

    2012-07-01

    Electricity market models, implemented as dynamic programming problems, have been applied widely to identify possible pathways towards a cost-optimal and low carbon electricity system. However, the joint optimization of generation and transmission remains challenging, mainly due to the fact that different characteristics and rules apply to commercial and physical exchanges of electricity in meshed networks. This paper presents a methodology that allows to optimize power generation and transmission infrastructures jointly through an iterative approach based on power transfer distribution factors (PTDFs). As PTDFs are linear representations of the physical load flow equations, they can be implemented in a linear programming environment suitable for large scale problems such as the European power system. The algorithm iteratively updates PTDFs when grid infrastructures are modified due to cost-optimal extension and thus yields an optimal solution with a consistent representation of physical load flows. The method is demonstrated on a simplified three-node model where it is found to be stable and convergent. It is then scaled to the European level in order to find the optimal power system infrastructure development under the prescription of strongly decreasing CO{sub 2} emissions in Europe until 2050 with a specific focus on photovoltaic (PV) power. (orig.)

  12. An On-Time Power-Aware Scheduling Scheme for Medical Sensor SoC-Based WBAN Systems

    Directory of Open Access Journals (Sweden)

    Jung-Guk Kim

    2012-12-01

    Full Text Available The focus of many leading technologies in the field of medical sensor systems is on low power consumption and robust data transmission. For example, the implantable cardioverter-defibrillator (ICD, which is used to maintain the heart in a healthy state, requires a reliable wireless communication scheme with an extremely low duty-cycle, high bit rate, and energy-efficient media access protocols. Because such devices must be sustained for over 5 years without access to battery replacement, they must be designed to have extremely low power consumption in sleep mode. Here, an on-time, energy-efficient scheduling scheme is proposed that performs power adjustments to minimize the sleep-mode current. The novelty of this scheduler is that it increases the determinacy of power adjustment and the predictability of scheduling by employing non-pre-emptible dual priority scheduling. This predictable scheduling also guarantees the punctuality of important periodic tasks based on their serialization, by using their worst case execution time and the power consumption optimization. The scheduler was embedded into a system on chip (SoC developed to support the wireless body area network—a wakeup-radio and wakeup-timer for implantable medical devices. This scheduling system is validated by the experimental results of its performance when used with life-time extensions of ICD devices.

  13. CFD Simulations of a Regenerative Process for Carbon Dioxide Capture in Advanced Gasification Based Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Arastoopour, Hamid [Illinois Inst. of Technology, Chicago, IL (United States); Abbasian, Javad [Illinois Inst. of Technology, Chicago, IL (United States)

    2014-07-31

    the method of moments, called Finite size domain Complete set of trial functions Method Of Moments (FCMOM) was used to solve the population balance equations. The PBE model was implemented in a commercial CFD code, Ansys Fluent 13.0. The code was used to test the model in some simple cases and the results were verified against available analytical solution in the literature. Furthermore, the code was used to simulate CO2 capture in a packed-bed and the results were in excellent agreement with the experimental data obtained in the packed bed. The National Energy Laboratory (NETL) Carbon Capture Unit (C2U) design was used in simulate of the hydrodynamics of the cold flow gas/solid system (Clark et al.58). The results indicate that the pressure drop predicted by the model is in good agreement with the experimental data. Furthermore, the model was shown to be able to predict chugging behavior, which was observed during the experiment. The model was used as a base-case for simulations of reactive flow at elevated pressure and temperatures. The results indicate that by controlling the solid circulation rate, up to 70% CO2 removal can be achieved and that the solid hold up in the riser is one of the main factors controlling the extent of CO2 removal. The CFD/PBE simulation model indicates that by using a simulated syngas with a composition of 20% CO2, 20% H2O, 30% CO, and 30% H2, the composition (wet basis) in the reactor outlet corresponded to about 60% CO2 capture with and exit gas containing 65% H2. A preliminary base-case-design was developed for a regenerative MgO-based pre-combustion carbon capture process for a 500 MW IGCC power plant. To minimize the external energy requirement, an extensive heat integration network was developed in Aspen/HYSYS® to produce the steam required in the regenerator and heat integration. In this process, liquid CO2 produced at 50 atm can easily be pumped and sequestered or stored. The preliminary economic analyses indicate that the

  14. Wireless power transfer system

    Science.gov (United States)

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2016-02-23

    A system includes a first stage of an inductive power transfer system with an LCL load resonant converter with a switching section, an LCL tuning circuit, and a primary receiver pad. The IPT system includes a second stage with a secondary receiver pad, a secondary resonant circuit, a secondary rectification circuit, and a secondary decoupling converter. The secondary receiver pad connects to the secondary resonant circuit. The secondary resonant circuit connects to the secondary rectification circuit. The secondary rectification circuit connects to the secondary decoupling converter. The second stage connects to a load. The load includes an energy storage element. The second stage and load are located on a vehicle and the first stage is located at a fixed location. The primary receiver pad wirelessly transfers power to the secondary receiver pad across a gap when the vehicle positions the secondary receiver pad with respect to the primary receiver pad.

  15. Compact CH4 sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser

    Science.gov (United States)

    Dong, Lei; Li, Chunguang; Sanchez, Nancy P.; Gluszek, Aleksander K.; Griffin, Robert J.; Tittel, Frank K.

    2016-01-01

    A tunable diode laser absorption spectroscopy-based methane sensor, employing a dense-pattern multi-pass gas cell and a 3.3 μm, CW, DFB, room temperature interband cascade laser (ICL), is reported. The optical integration based on an advanced folded optical path design and an efficient ICL control system with appropriate electrical power management resulted in a CH4 sensor with a small footprint (32 × 20 × 17 cm3) and low-power consumption (6 W). Polynomial and least-squares fit algorithms are employed to remove the baseline of the spectral scan and retrieve CH4 concentrations, respectively. An Allan-Werle deviation analysis shows that the measurement precision can reach 1.4 ppb for a 60 s averaging time. Continuous measurements covering a seven-day period were performed to demonstrate the stability and robustness of the reported CH4 sensor system.

  16. 基于PowerBuilder开发网上购票系统%Online Booking System Based on PowerBuilder

    Institute of Scientific and Technical Information of China (English)

    张媛; 张玉林; 袁安平

    2007-01-01

    分布式数据库系统是数据库领域的新技术,是数据库技术、计算机网络技术和分布式处理相结合的产物.介绍了利用PowerBuilder环境开发分布式数据库系统应用的方法及其原理,并给出运用PowerBuilder开发网上数据库应用系统的实例(网上购票系统).利用分布式数据库系统和网络功能实现网上购票,对民航、铁路和公路交通运输部门有着重要的意义.

  17. A Kalman filtering based control scheme for the improvement of dynamic performance of an AC/DC power system

    Science.gov (United States)

    Pecen, Recayi

    In this dissertation, two major accomplishments are achieved. First, the feasibility of a proposed Wyoming to California HVDC system having the ratings of 1000 MW, ±500 kV, 2 kA, 860 miles and 12-pulse bipolar lines is shown for exporting Wyoming's electrical power resources to the heavy loaded western states. The second and the main objective of this dissertation is the development of a Kalman filtering (KF) based control scheme applied to an ac/dc power system. It is shown that the use KF algorithm to estimate some of the system states and utilizing them in a proportional Integral (PI) controller which has a better performance for this specific control scheme have resulted in a better dynamic performance of the proposed system. A set of case studies has shown that the system dynamic performance is improved for most of the contingencies. Ac and dc noisy voltage and current measurements received from the simulated ac/dc power system are sent to the KF estimation algorithm. The noise-separated best estimates of measurable states are computed and sent to a PI controller-based current and firing angle control subsections in order to provide a set of optimum thyristor firing angles for both converter stations during and after contingencies until the normal operation is reached. To evaluate the dynamic performance of the system with the KF algorithm, the model is simulated by a well-known digital simulation package, Electromagnetic Transients DC Program (PSCAD/EMTDC) of Manitoba HVDC Research Center. To apply the KF algorithm, a general, linearized, state-space model of the proposed ac/dc system, appropriate for analyzing both the KF and the electromagnetics transients, is derived first. The derived model enables the representation of an ac power system with two ac sources and one HVDC line with a parallel ac line connecting the two systems. It is shown that system eigenvalues of the discretized system model for a normal operating point are inside the unit circle that

  18. MISAT : Designing a Series of Powerful Small Satellites Based upon Micro Systems Technology

    NARCIS (Netherlands)

    Gill, E.; Monna, G.L.E.; Scherpen, J.M.A.; Verhoeven, C.J.M.

    2007-01-01

    MISAT is a research and development cluster which will create a small satellite platform based on Micro Systems Technology (MST) aiming at innovative space as well as terrestrial applications. MISAT is part of the Dutch MicroNed program which has established a microsystems infrastructure to fully ex

  19. AC power supply systems

    International Nuclear Information System (INIS)

    An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

  20. Neural-net based calculation of voltage dips at maximum angular swing in direct transient stability analysis [of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M. (Inst. ' Nikola Tesla' , Belgrade (Yugoslavia)); Sobajic, D.J.; Yohhan Pao (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE inc., Cleveland, OH (United States))

    1992-10-01

    In heavily stressed power systems, post-fault transient voltage dips can lead to undesired tripping of industrial drives and large induction motors. The lowest transient voltage dips occur when fault clearing times are less than critical ones. In this paper, we propose a new iterative analytical methodology to obtain more accurate estimates of voltage dips at maximum angular swing in direct transient stability analysis. We also propose and demonstrate the possibility of storing the results of these computations in the associative memory (AM) system, which exhibits remarkable generalization capabilities. Feature-based models stored in the AM can be utilized for fast and accurate prediction of the location, duration and the amount of the worst voltage dips, thereby avoiding the need and cost for lengthy time-domain simulations. Numerical results obtained using the example of the New England power system are presented to illustrate our approach. (Author)

  1. A least square support vector machine-based approach for contingency classification and ranking in a large power system

    Directory of Open Access Journals (Sweden)

    Bhanu Pratap Soni

    2016-12-01

    Full Text Available This paper proposes an effective supervised learning approach for static security assessment of a large power system. Supervised learning approach employs least square support vector machine (LS-SVM to rank the contingencies and predict the system severity level. The severity of the contingency is measured by two scalar performance indices (PIs: line MVA performance index (PIMVA and Voltage-reactive power performance index (PIVQ. SVM works in two steps. Step I is the estimation of both standard indices (PIMVA and PIVQ that is carried out under different operating scenarios and Step II contingency ranking is carried out based on the values of PIs. The effectiveness of the proposed methodology is demonstrated on IEEE 39-bus (New England system. The approach can be beneficial tool which is less time consuming and accurate security assessment and contingency analysis at energy management center.

  2. Development of a risk monitoring system for nuclear power plants based on GO-FLOW methodology

    International Nuclear Information System (INIS)

    Highlights: • A method for developing Living PSA is proposed. • Living PSA is easy to update with online modification to system model file. • A risk monitoring system is designed and developed using the GO-FLOW. • The risk monitoring system is useful for plant daily operation risk management. - Abstract: The paper presents a risk monitoring system developed based on GO-FLOW methodology which is a success-oriented system reliability modeling technique for phased mission as well as time-dependent problems analysis. The risk monitoring system is designed to receive information on plant configuration changes either from equipment failures, operator interventions, or maintenance activities, then update the Living PSA model with online modification to the system GO-FLOW model file which contains all the functional modes of equipment represented by a proposed generalized GO-FLOW modeling structure, and display risk values graphically. The risk monitoring system can be used to assist safety engineers and plant operators in their maintenance management and daily operation risk management at NPPs

  3. A Critical Review on Wind Turbine Power Curve Modelling Techniques and Their Applications in Wind Based Energy Systems

    Directory of Open Access Journals (Sweden)

    Vaishali Sohoni

    2016-01-01

    Full Text Available Power curve of a wind turbine depicts the relationship between output power and hub height wind speed and is an important characteristic of the turbine. Power curve aids in energy assessment, warranty formulations, and performance monitoring of the turbines. With the growth of wind industry, turbines are being installed in diverse climatic conditions, onshore and offshore, and in complex terrains causing significant departure of these curves from the warranted values. Accurate models of power curves can play an important role in improving the performance of wind energy based systems. This paper presents a detailed review of different approaches for modelling of the wind turbine power curve. The methodology of modelling depends upon the purpose of modelling, availability of data, and the desired accuracy. The objectives of modelling, various issues involved therein, and the standard procedure for power performance measurement with its limitations have therefore been discussed here. Modelling methods described here use data from manufacturers’ specifications and actual data from the wind farms. Classification of modelling methods, various modelling techniques available in the literature, model evaluation criteria, and application of soft computing methods for modelling are then reviewed in detail. The drawbacks of the existing methods and future scope of research are also identified.

  4. Fault Diagnosis of Power System Based on Improved Genetic Optimized BP-NN

    Directory of Open Access Journals (Sweden)

    Yuan Pu

    2015-01-01

    Full Text Available BP neural network (Back-Propagation Neural Network, BP-NN is one of the most widely neural network models and is applied to fault diagnosis of power system currently. BP neural network has good self-learning and adaptive ability and generalization ability, but the operation process is easy to fall into local minima. Genetic algorithm has global optimization features, and crossover is the most important operation of the Genetic Algorithm. In this paper, we can modify the crossover of traditional Genetic Algorithm, using improved genetic algorithm optimized BP neural network training initial weights and thresholds, to avoid the problem of BP neural network fall into local minima. The results of analysis by an example, the method can efficiently diagnose network fault location, and improve fault-tolerance and grid fault diagnosis effect.

  5. The electric power engineering handbook power systems

    CERN Document Server

    2012-01-01

    Power Systems, Third Edition (part of the five-volume set, The Electric Power Engineering Handbook) covers all aspects of power system protection, dynamics, stability, operation, and control. Under the editorial guidance of L.L. Grigsby, a respected and accomplished authority in power engineering, and section editors Andrew Hanson, Pritindra Chowdhuri, Gerry Sheble, and Mark Nelms, this carefully crafted reference includes substantial new and revised contributions from worldwide leaders in the field. This content provides convenient access to overviews and detailed information on a diverse arr

  6. Robust Quantum Based Low-power Switching Technique to improve System Performance

    Directory of Open Access Journals (Sweden)

    M. Lavanya

    2013-08-01

    Full Text Available Round Robin (RR is a pre-emptive algorithm used in multiprogrammed, conventional systems to schedule all the processes which are present in ready queue for execution. It has some advantages over other algorithms i.e., it gives a chance to all process to utilize processor for equal time interval. But this technique increases average turnaround time, average waiting time and if quantum value is very less, then CPU time is wasted in switching between processes and increases overheads. If it is high, the algorithm just works like FCFS and cannot be used in time sharing systems. The algorithm performance depends on quantum value. Turnaround time and waiting time are the criteria of the system which should be maintained as less as possible. Standard RR (SRR algorithm does not posses logic infixing quantum value. In our paper we propose Low-power Switching (LS algorithm which reduces context switching and also reduces average waiting time and average turnaround time. So throughput ofsystem will be raised. Experimental analysis shows the feasibility of the proposed algorithm which gives better turnaround time, waiting time and context switching compared with SRR technique and some related works. Pseudo code has been generated to prove the work.

  7. Reliability analysis of microprocessor-based control and protection systems in nuclear power plants

    International Nuclear Information System (INIS)

    This paper will present an overview of the objectives, methods, and limitations associated with the reliability assessment of microprocessor based control and protection systems being put into use today. The paper will be structured in a top down format presenting a general method which may be applied when assessing these types of systems. Specific discussion will be presented regarding current issues in the area of safety and licensing. Generic and unique methods which have been developed to assess these systems in a practical and efficient manner will be discussed, including discussion of the open-quotes Functional Block Analysisclose quotes method which may be used to predict the effectiveness of on-line checks and diagnostics. The models and results will be discussed. As a final note, general observations and findings regarding the typical performance of these systems, as demonstrated by the methods discussed, will be presented

  8. Wind power plant system services

    DEFF Research Database (Denmark)

    Basit, Abdul; Altin, Müfit

    Traditionally, conventional power plants have the task to support the power system, by supplying power balancing services. These services are required by the power system operators in order to secure a safe and reliable operation of the power system. However, as in the future the wind power...... is going more and more to replace conventional power plants, the sources of conventional reserve available to the system will be reduced and fewer conventional plants will be available on-line to share the regulation burden. The reliable operation of highly wind power integrated power system might...... then beat risk unless the wind power plants (WPPs) are able to support and participate in power balancing services. The objective of this PhD project is to develop and analyse control strategies which can increase the WPPs capability to provide system services, such as active power balancing control...

  9. Maximum PowerPoint Tracking of PV System Based on a SEPIC Converter Using Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Vrashali Jadhav

    2016-01-01

    Full Text Available This paper presents the MPPT (Maximum power point tracking operation of PV (Photovoltaic system based on a SEPIC (Single Ended Primary Inverter Converter converter using fuzzy logic controller. MPPT method such as Incremental conductance base on FLC (Fuzzy Logic Controller is used to extract maximum output power of the PV system. PV energy is the most essential energy resources since it is pollution free, clean and endless. The FLC proposed scheme is interface with the MPPT to generate the PWM (Pulse Width Modulation for the SEPIC controller for maximum power point tracking operation.FLChas used Mamdani’s method for convergent and divergent of membership function. FLC is used for more efficient performance under the variation in different atmosphere. The fuzzy logic controller with SEPIC for MPPT scheme extract the maximum power point tracking without any change in the voltage at the inverter at different load condition. The behavior of the converter and controller tested in simulation at different operating conditions. Proposed scheme is used for accurately tracking maximum point and also send the smooth, error free signal to the inverter.

  10. Power Electronics in Wind Turbine Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chen, Zhe; Teodorescu, Remus;

    2006-01-01

    the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power systems, power production and end-user application. This paper discuss the most emerging renewable energy source, wind energy, which by means of power...... electronics is changing from being a minor energy source to be acting as an important power source in the energy system. By that wind power is also getting an added value in the power system operation....

  11. Experience in installing a microprocessor-based protection system on a UK nuclear power plant

    International Nuclear Information System (INIS)

    This paper describes a recently completed project to install a microprocessor-based reactor protection system on a twin reactor station in the United Kingdom. This represented the first application of digital technology as part of such a system in the UK. The background of the application and details of the chosen solution are provided. The experience gained during the installation, commissioning and early operation of the equipment is reviewed by the operators. Interactions between the utility and the regulatory body are outlined and the impact of the regulatory process on the utility's resources and the project timescales are discussed

  12. A High-Efficiency Compact SiC-based Power Converter System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Wide bandgap SiC power devices have the potential for reliable operations at higher junction temperatures, higher voltages, higher frequencies and thus higher power...

  13. A High-Efficiency Compact SiC-based Power Converter System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Wide-bandgap SiC semiconductors have been recently investigated for use in power devices, because of their potential capabilities of operating at high power...

  14. Modeling and Control of Grid Side Converter in Wind Power Generation System Based on Synchronous VFDPC with PLL

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan;

    2011-01-01

    Virtual flux oriented direct power control (VFDPC) is combined space vector modulation (SVM) with PI of DC-link voltage, active power and reactive power to control the grid side converter in wind power generation system in this paper. VFDPC has reached good performances with PLL (phase lock loop)...

  15. Web-Based Application for the Sizing of a Photovolatic (PV) Solar Power System

    OpenAIRE

    F.K. Ariyo; B.D. Famutimi; T.O. Olowu; S.A. Akintade; Abbas, A

    2016-01-01

    The harnessing of solar energy, especially for provision of energy for residential consumption, has been on the rise in developing countries, especially Nigeria, in recent times. Due to this reason, there is the need for a tool which makes the design of the system needed to harness this abundant energy more accurate and efficient by considering several factors including specific climate conditions of the country. This paper presents the design and development of a web-based application tha...

  16. Design and development of permanent magnet based composite magnet system for biasing of high power ferrite circulator

    International Nuclear Information System (INIS)

    The high power ferrite circulators (505 MHz and 650 MHz) which are being indigenously develop for RF system of Indus-2 and Proton Linac. A composite magnet system is required to provide stable and tunable magnetic field for biasing of high power ferrite circulator to operate in below/above resonance mode. The biasing static magnetic field is an important parameter for optimization of operating state of high power ferrite circulator. The permanent magnet based H-type composite magnet system with variable gap has been designed using Opera 3D to generate tunable magnetic field of 0.22 T ± 0.025 T in the pole gap of 35 mm over 182 mm pole diameter. This magnet system is developed using the combination of strontium ferrite permanent magnet disks (200 mm dia x 25 mm thick) and excitation coils (pole coils). The required magnetic field in the pole gap produced by permanent magnets and the fine tuning of the magnetic field is achieved by varying the DC current through excitation coils. Magnet yoke plates and pole pieces fabricated from low carbon steel whereas pole coils made from enameled copper wire. Magnetic field measurements of this magnet system has been carried out using Hall probe based three axis magnet measurement bench. The operating points of permanent magnet have been calculated from the measured magnetic field results. A detailed 3D magnetic field simulation, magnet development and magnetic field measurement results of permanent magnet based composite magnet system wilI be discussed in this paper. (author)

  17. Development of a vibration pattern and maintenance data based expert system for water-cooled and -moderated nuclear power plants

    International Nuclear Information System (INIS)

    This report describes the activities of the research project entitled 'Development of a Vibration Pattern and Maintenance-data Based Expert System...', in the period from January 1994 to November 1994. In keeping with the detailed work plan for the past 12 months we have: developed of the prototype expert system of MCPs including knowledge base development, maintenance event data base development, tuning of the users interface; tested and tuned the system, with respect to the users' requirements; enlarged the preliminary knowledge base related to the behaviour of MCPs of WWER type NPPs; developed a prototype expert system using LEVEL5 object, together with the MMI and KB mentioned above. The ARGUS-E expert system is design to support the maintenance personnel, and wants to be a tool on the palette of the state dependent maintenance or RCM. To enlarge the knowledge base we used the measuring and diagnostic experience gathered with ARGUS diagnostic systems, at Paks (Hungary) NPP, and by the maintenance personnel of the power plant. (author). 7 refs, 2 figs

  18. Balancing modern Power System with large scale of wind power

    OpenAIRE

    Basit, Abdul; Altin, Müfit; Anca Daniela HANSEN; Sørensen, Poul Ejnar

    2014-01-01

    Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the s...

  19. Power System for Intelligent House

    Directory of Open Access Journals (Sweden)

    Michal Jahelka

    2010-01-01

    Full Text Available Power supply of intelligent houses or house phones is possible to do with standard transformer with voltage stabilizer or with intelligent power supply. Standard solution can has as a result of failure fuse blown or fire occurrence. Intelligent power supply switch off power and tests with little current whether short circuit is removed. After it resume system power supply. At the same time it cares of system backup with accumulator, informs control system about short circuit or failure net power supply, or can switch off all system power after command from control system.

  20. Sliding Mode Extremum Seeking Control Scheme Based on PSO for Maximum Power Point Tracking in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Her-Terng Yau

    2013-01-01

    Full Text Available An extremum seeking control (ESC scheme is proposed for maximum power point tracking (MPPT in photovoltaic power generation systems. The robustness of the proposed scheme toward irradiance changes is enhanced by implementing the ESC scheme using a sliding mode control (SMC law. In the proposed approach, the chattering phenomenon caused by high frequency switching is suppressed by means of a sliding layer concept. Moreover, in implementing the proposed controller, the optimal value of the gain constant is determined using a particle swarm optimization (PSO algorithm. The experimental and simulation results show that the proposed PSO-based sliding mode ESC (SMESC control scheme yields a better transient response, steady-state stability, and robustness than traditional MPPT schemes based on gradient detection methods.

  1. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical...

  2. Operation and maintenance experience with computer based systems of Nuclear Power Plant - Kaiga Generating Station-1 and 2

    International Nuclear Information System (INIS)

    Many computerized systems like PDCS, CCTMS, BMS, COIS have been introduced for the first time in NPCIL at KGS. As these systems were new and more sophisticated compared to the equivalent systems at earlier plants, problems and challenges encountered during operation and maintenance were many and different of its kind. As the technology update in the IT field is fast, obsoleteness of the hardware and software poses a threat to the system availability and maintenance which remains a great concern in a Nuclear Power Plant. This paper gives details of the major problems resolved and steps taken for a trouble free operation of some computer based systems at Kaiga Generating Station 1 and 2. (author)

  3. Particle Swarm Optimization Based Reactive Power Optimization

    CERN Document Server

    Sujin, P R; Linda, M Mary

    2010-01-01

    Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

  4. Power control system and method

    Science.gov (United States)

    Steigerwald, Robert Louis; Anderson, Todd Alan

    2006-11-07

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  5. Embedded System Power Design Based on Photovoltaic Power Generation%光伏发电的嵌入式系统电源设计

    Institute of Scientific and Technical Information of China (English)

    潘野; 童玲; 田雨

    2011-01-01

    Embedded system power based on photovokaic power generation uses lead-acid battery,solar panels and corresponding circuit to collect energy,store and switch. Intelligent charging module constituted by UC3906 lead-acid battery charging management chip and its peripheral circuit prolongs the service life of lead-acid batteries. Buck-Boost circuit and microcontroller control loops provide solar panels maximum power tracing which guarantees the efficiency. Double power switch function adopted by photoelectric couplers insures the power supply in extreme conditions of permanence. The energy source is from the sun with the advantage of environmental protection and energy saving. The power circuit is relatively simple and only needs to be provided with basic level control by microcontroller, perfect for embedded system power supply resettlement in the field.%基于光伏发电的嵌入式系统电源,利用铅酸电池、太阳能电池板和相应电路,调控光能采集并进行储存。通过UC3906铅酸电池充电管理芯片及外围电路构成智能充电模块,最大限度延长了铅酸电池的使用寿命;利用Buck—Boost电路和单片机控制回路提供太阳能电池板最大功率跟踪,保证了供电效率;采用光电耦合器提供双电源切换功能,确保在极端条件下供电的持久性。电源能量来自太阳,具有环保节能的优势;电源电路相对简单,利于搭建,仅需单片机提供基本的控制电平,非常适合作为安置在野外的嵌入式系统电源。

  6. Nonlinear phenomenon in monocrystalline silicon based PV module for low power system: Lead acid battery for low energy storage

    Science.gov (United States)

    El Amrani, A.; El Amraoui, M.; El Abbassi, A.; Messaoudi, C.

    2014-11-01

    In the present work, we report the indoor photo-electrical measurements of monocrystalline silicon based photovoltaic (PV) module associated with 4 Ah lead acid battery as a storage unit for low power PV system applications. Concerning the PV module, our measurements show, at low illumination regime, that the short circuit current ISC increases linearly with the illumination power levels. Moreover, for high illumination levels, the mechanism of bimolecular recombination and space charge limitation may be intensified and hence the short current of the PV module ISCMod depends sublinearly on the incident optical power; the behavior is nonlinear. For the open circuit voltage of the PV module VOCMod measurements, a linear variation of the VOCMod versus the short circuit current in semi-logarithmic scale has been noticed. The diode ideality factor n and diode saturation current Is have been investigated; the values of n and Is are approximately of 1.3 and 10-9 A, respectively. In addition, we have shown, for different discharging-charging currents rates (i.e. 0.35 A, 0.2 A and 0.04 A), that the battery voltage decreases with discharging time as well as discharging battery capacity, and on the other hand it increases with the charging time and will rise up until it maximized value. The initial result shows the possibility to use such lead acid battery for low power PV system, which is generally designed for the motorcycle battery.

  7. Stability Analysis of Three-Phase AC Power Systems Based on Measured D-Q Frame Impedances

    OpenAIRE

    Wen, Bo

    2015-01-01

    Small-signal stability is of great concern for distributed power systems with a large number of regulated power converters. These converters are constant-power loads (CPLs) exhibit a negative incremental input resistance within the output voltage regulation bandwidth. In the case of dc systems, design requirements for impedances that guarantee stability have been previously developed and are used in the design and specification of these systems. In terms of three-phase ac systems, a mathemati...

  8. Efficiency enhancement of stationary solar energy based power conversion systems in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Sharan, Anand M. [Faculty of Engineering, Memorial University of Newfoundland, St. John' s, Newfoundland (Canada)

    2009-09-15

    This paper presents the optimum energy conversion conditions of stationary photovoltaic panels used for electrical power generation. The results are arrived at after performing calculations for 180 days in a given year at the latitude of St. John's, Newfoundland. The latitude of this city is close to other Canadian major population centers. Various angular orientations of sun's rays on the earth are considered. On a given day, the incident energy flux of sun is resolved into three components, and the conversion efficiency is based on the flux normal to the panels. The efficiency of conversion of the incident energy is measured with respect to a solar tracking process. The numbers of days in a given year are divided into two groups - one between the winter solstice and the spring equinox, and another between the spring equinox and the summer solstice. The results show the existence of two maxima, one for each of the two periods. By setting the panels at each of these maxima, very significant improvement in energy conversion can be achieved. (author)

  9. Low Power Modulo 2n+1 Adder Based on Carry Save Diminished-One Number System

    Directory of Open Access Journals (Sweden)

    Somayeh Timarchi

    2008-01-01

    Full Text Available Modulo 2n+1 adders find great applicability in several applications including RNS implementations. This paper presents a new number system called Carry Save Diminished-one for modulo 2n+1 addition and a novel addition algorithm for its operands. In this paper, we also present a novel architectures for designing modulo 2n+1 adders, based on parallel-prefix carry computation units. CMOS implementations reveal the superiority of the resulting adders against previously reported solutions in terms of implementation area and delay.

  10. Computer-aided power systems analysis

    CERN Document Server

    Kusic, George

    2008-01-01

    Computer applications yield more insight into system behavior than is possible by using hand calculations on system elements. Computer-Aided Power Systems Analysis: Second Edition is a state-of-the-art presentation of basic principles and software for power systems in steady-state operation. Originally published in 1985, this revised edition explores power systems from the point of view of the central control facility. It covers the elements of transmission networks, bus reference frame, network fault and contingency calculations, power flow on transmission networks, generator base power setti

  11. Wind Powered Sprinkler System

    Directory of Open Access Journals (Sweden)

    Chin Jung Huang

    2013-06-01

    Full Text Available Due to limited energy resources, excessive emission of CO2, global warming, increase of mean temperature, serious impacts have resulted on our living environment, and thus, energy saving and carbon reduction have become urgent issues. Planting grass, flowers and trees can absorb and reduce CO2, thus meeting the requirements for energy saving and carbon reduction in environmental protection. At present, most of lawns or gardens in Taiwan are maintained by manual or traditional semiautomatic watering device. Whether the lawn needs to be watered and the amount of water to be sprinkled depends on subjective decision. When the lawn is watered without examining the moisture content of the soil beforehand, it causes waste of time, labor, water and cost. The intelligent wind powered watering system developed by this study used an electromechanical integrated design system to control the humidity probe, and used the electricity generated by natural wind power and pumping device to control the sprinkling action. This system sprinkles water by sensing the soil moisture content, and stops sprinkling automatically when the soil moisture content is enough, thus achieving the purposes of cost and energy saving.

  12. Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-07-01

    This report discusses Test Campaign TC12 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (SW) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC12 began on May 16, 2003, with the startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until May 24, 2003, when a scheduled outage occurred to allow maintenance crews to install the fuel cell test unit and modify the gas clean-up system. On June 18, 2003, the test run resumed when operations relit the start-up burner, and testing continued until the scheduled end of the run on July 14, 2003. TC12 had a total of 733 hours using Powder River Basin (PRB) subbituminous coal. Over the course of the entire test run, gasifier temperatures varied between 1,675 and 1,850 F at pressures from 130 to 210 psig.

  13. Model based design of efficient power take-off systems for wave energy converters

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Andersen, Torben Ole; Pedersen, Henrik C.

    2011-01-01

    The Power Take-Off (PTO) is the core of a Wave Energy Converter (WECs), being the technology converting wave induced oscillations from mechanical energy to electricity. The induced oscillations are characterized by being slow with varying frequency and amplitude. Resultantly, fluid power is often...

  14. 3G POWER GRID SYSTEM

    OpenAIRE

    Saiyad Tausif Ali *; Gaurav Pawar; Pragati Rathi; Mandar Pathak

    2016-01-01

    3G Power grid system is dual side stream of electricity and automated construct information and distributed advanced energy delivery network. In this 3G Power grid system avoided the thermal and hydro sources of energy. By using the solar power and wind power energy will generate electricity according with the condition of nature. 3G Power grid system provides the facility of generating as well as marketing of electricity not only for the producers but also for consumers. By using megabytes o...

  15. Development of user interface to support automatic program generation of nuclear power plant analysis by module-based simulation system

    International Nuclear Information System (INIS)

    Module-based Simulation System (MSS) has been developed to realize a new software work environment enabling versatile dynamic simulation of a complex nuclear power system flexibly. The MSS makes full use of modern software technology to replace a large fraction of human software works in complex, large-scale program development by computer automation. Fundamental methods utilized in MSS and developmental study on human interface system SESS-1 to help users in generating integrated simulation programs automatically are summarized as follows: (1) To enhance usability and 'communality' of program resources, the basic mathematical models of common usage in nuclear power plant analysis are programed as 'modules' and stored in a module library. The information on usage of individual modules are stored in module database with easy registration, update and retrieval by the interactive management system. (2) Target simulation programs and the input/output files are automatically generated with simple block-wise languages by a precompiler system for module integration purpose. (3) Working time for program development and analysis in an example study of an LMFBR plant thermal-hydraulic transient analysis was demonstrated to be remarkably shortened, with the introduction of an interface system SESS-1 developed as an automatic program generation environment. (author)

  16. Innovation design of power nuclear systems

    International Nuclear Information System (INIS)

    Efforts to ensure design and manufacturing innovations in the sphere of power reactors have reached the level of the large-scale inter-state cooperation. Some nuclear power systems are under evaluation in terms of the IAEA International Project dealing with the innovative power reactors and fuel cycles. In Japan the efforts to design fast sodium low-power reactor to serve as a power source in high-cost power regions and in developing power low-consuming countries are in progress. In South Korea the efforts to design a high-power reactor, that is, the APR1400 reactor based on the KSNP Korean available standard plant are in progress

  17. Power system analysis

    CERN Document Server

    Kumar, Narenkumarsanjiv

    2010-01-01

    This book has been written for B. Tech/B.Sc (Engg.)/B.E. students. It consists of seven chapters in all, covering the complete topics systematically and exhaustively. The book is designed as a complete course text of 'Power System Analysis' for undergraduate students of electrical engineering in accordance with the syllabi of Delhi Technological University, Indraprastha University, and Other India Universities/Institutions. This book is to meet the needs of Third Year (6th Semester) students of B.Tech. (Electrical Engineering and Electrical & Electronics Engineering) studying in Engineering co

  18. Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

    OpenAIRE

    Jaw-Kuen Shiau; Yu-Chen Wei; Min-Yi Lee

    2015-01-01

    This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT) system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is oper...

  19. Aid system in the attention direction for accidents diagnosis at nuclear power plants based on artificial intelligence

    International Nuclear Information System (INIS)

    Transient identification in Nuclear Power Plant (NPP) is often a very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in NPPs. The bases for the transient identification relay on the evidence that different system faults and anomalies lead to different pattern evolution in the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments that represents a specific type of event Several systems based on specialist systems, neural-networks, and fuzzy logic have been developed for transient identification. In the work, we investigate the possibility of using a Neuro Fuzzy modeling tool for efficient transient identification, aiming to helping the operator crew to take decisions relative to the procedure to be followed in situations of accidents/transients at NPPs. The proposed system uses artificial neural networks (ANN) as first level transient diagnostic After the ANN has done the preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. A preliminary evaluation of the developed system was made at the Human-System Interface Laboratory (LABIHS). The obtained results show that the system can help the operators to take decisions during transients/accidents in the plant (author)

  20. 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

  1. A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: CEDINFO

    Energy Technology Data Exchange (ETDEWEB)

    Say, Nuriye Peker; Yuecel, Muzaffer [Cukurova University, Adana (Turkey). Department of Landscape Architecture; Yilmazer, Mehmet [Bogazici University, Kandilli, Istanbul (Turkey). Kandilli Observatory and Earthquake Research Institute

    2007-12-15

    Environmental impact assessment (EIA) is a tool for decision makers to take into account the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data. In this study, a knowledge-based software - CEDINFO - developed by authors was introduced. CEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power station, hydraulic station, nuclear station) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. CEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations. (author)

  2. Real-Time Vehicle Energy Management System Based on Optimized Distribution of Electrical Load Power

    Directory of Open Access Journals (Sweden)

    Yuefei Wang

    2016-10-01

    Full Text Available As a result of severe environmental pressure and stringent government regulations, refined energy management for vehicles has become inevitable. To improve vehicle fuel economy, this paper presents a bus-based energy management system for the electrical system of internal combustion engine vehicles. Both the model of an intelligent alternator and the model of a lead-acid battery are discussed. According to these models, the energy management for a vehicular electrical system is formulated as a global optimal control problem which aims to minimize fuel consumption. Pontryagin’s minimum principle is applied to solve the optimal control problem to realize a real-time control strategy for electrical energy management in vehicles. The control strategy can change the output of the intelligent alternator and the battery with the changes of electrical load and driving conditions in real-time. Experimental results demonstrate that, compared to the traditional open-loop control strategy, the proposed control strategy for vehicle energy management can effectively reduce fuel consumption and the fuel consumption per 100 km is decreased by approximately 1.7%.

  3. Offshore Variability in Critical Weather Conditions in Large-Scale Wind Based Danish Power System

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar;

    2013-01-01

    , the chances of losing several GW of wind power due to critical weather conditions in a very short time period could potentially jeopardize the whole system’s reliability and stability. Forecasting such events is not trivial and the results so far are not encouraging. When assessing the impact......Offshore wind power has a significant development potential, especially in North Europe. The geographical concentration of offshore wind power leads to increased variability and in the case of critical weather conditions it may lead to sudden and considerable loss of production. In this context...

  4. Selection of working fluids for a novel low-temperature geothermally-powered ORC based cogeneration system

    International Nuclear Information System (INIS)

    Highlights: → Performances of a novel cogeneration system using low-temperature geothermal sources under disturbance conditions were investigated. → It aimed at identifying appropriate fluids yielding high PPR and QQR values. → Fluids group presenting higher normal boiling point values showed averagely 7.7% higher PPR with a larger variation than QQR values under disturbance conditions. → Smaller TP value, higher ηt value, higher geothermal source parameters and lower heating supply parameters led to higher PPR values but lower QQR values. -- Abstract: A novel cogeneration system driven by low-temperature geothermal sources was investigated in this study. This system consists of a low-temperature geothermally-powered organic Rankine cycle (ORC) subsystem, an intermediate heat exchanger and a commercial R134a-based heat pump subsystem. The main purpose is to identify appropriate fluids which may yield high PPR (the ratio of power produced by the power generation subsystem to power consumed by the heat pump subsystem) value and QQR (the ratio of heat supplied to the user to heat produced by the geothermal source) value. Performances of the novel cogeneration system under disturbance conditions have also been studied. Results indicate that fluids group presenting higher normal boiling point values shows averagely 7.7% higher PPR values and R236ea and R245ca outstand among the group. ΔTP (pinch temperature difference in heat exchangers) and ηt (turbine efficiency) values play more important roles on the variation of PPR values. QQR values change slightly with various ΔTP, ηt and ηrp (refrigerant pump efficiency) values while the variation range is larger under various geothermal source and heating supply parameters. Smaller ΔTP value, higher ηt value, higher geothermal source parameters and lower heating supply parameters lead to higher PPR values but lower QQR values.

  5. Exergetic and exergoeconomic evaluation of a solid-oxide fuel-cell-based combined heat and power generation system

    International Nuclear Information System (INIS)

    Highlights: • Exergy-based evaluations of a SOFC-based power generation system have been made. • The exergy of fuel and the exergy of product are rigorously defined. • Cost balance and auxiliary equations are formulated for the exergoeconomic analysis. • The cost structure of the overall system has been analyzed. • Suggestions are made for improving the cost effectiveness of the entire system. - Abstract: Exergetic and exergoeconomic evaluations have been carried out for a 100 kW-class solid-oxide fuel-cell-based combined heat and power generation system, to find out the measures that would improve its efficiency, and, more importantly, its cost effectiveness. The exergoeconomic analysis is an appropriate combination of an exergetic analysis and an economic analysis; through exergoeconomics, we obtain the real cost associated with each stream and with the inefficiencies within each component in a system. For the analyses, the exergies of fuel and the exergies of product for all components have been defined. Subsequently, the exergetic efficiency of each component has been evaluated. By combining the results obtained from an economic analysis with the results of the exergetic analysis, the cost structure of the overall system has been figured out. The components, showing higher exergoeconomic factors such as SOFC stack, fuel blower, heat recovery water pump, and inverter, need reduction of investment cost, even if the associated efficiency would decreased because of this cost reduction. For the components, exhibiting lower exergoeconomic factors such as integrated reformer, fuel/water pre-heater, and air pre-heater, the main focus should be on efficiency improvements, even if higher investment expenditures would be associated with such improvements

  6. Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    Southern Company Services

    2004-04-30

    This report discusses Test Campaign TC15 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Power Generation, Inc. (SPG) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC15 began on April 19, 2004, with the startup of the main air compressor and the lighting of the gasifier startup burner. The Transport Gasifier was shutdown on April 29, 2004, accumulating 200 hours of operation using Powder River Basin (PRB) subbituminous coal. About 91 hours of the test run occurred during oxygen-blown operations. Another 6 hours of the test run was in enriched-air mode. The remainder of the test run, approximately 103 hours, took place during air-blown operations. The highest operating temperature in the gasifier mixing zone mostly varied from 1,800 to 1,850 F. The gasifier exit pressure ran between 200 and 230 psig during air-blown operations and between 110 and 150 psig in oxygen-enhanced air operations.

  7. Harmonics in transmission power systems

    DEFF Research Database (Denmark)

    Wiechowski, Wojciech Tomasz

    , provided that background harmonic distortion, and the network configuration, are not changing during the measurement. It is shown that switching of a shunt linear power system component can result in variation of the harmonic levels that can be measured and used to verify the harmonic model of the network....... Three novel methods are also proposed, where switching of a series component can be used for the same purpose. Two of these methods are based on the determination of transfer harmonic impedance of the network and the third approach, which is actually used in the project, is based on injection......, in order to determine which power system component, when switched, results in the largest change in harmonic levels, some initial harmonic simulations, using the created harmonic model of Energinet.dk transmission network, are performed. The criterion is that the measuring equipment shall not be installed...

  8. A robust mixed H{sub 2}/H{sub {infinity}} based LFC of a deregulated power system including SMES

    Energy Technology Data Exchange (ETDEWEB)

    Shayeghi, H. [Technical Engineering Department, University of Mohaghegh Ardabili, Ardabil (Iran); Jalili, A. [Islamic Azad University, Ardabil Branch, Ardabil (Iran); Shayanfar, H.A. [Center of Excellence for Power Automation and Operation, Electrical Engineering Department, Iran University of Science and Technology, Tehran (Iran)

    2008-10-15

    This paper presents a new robust decentralized controller based on mixed H{sub 2}/H{sub {infinity}} control technique for the solution of load frequency control (LFC) problem including superconducting magnetic energy storage (SMES) in a deregulated electricity environment. To achieve decentralization, in each control area, the connections between this area and the rest of the system and the effects of possible contracts are treated as a set of new disturbance signals. In order to minimize effects of load disturbances and to achieve desired level of robust performance in the presence of modeling uncertainties and practical constraints on control action the idea of mixed H{sub 2}/H{sub {infinity}} control technique is being used for the solution of LFC problem. This newly developed design strategy combines advantage of H{sub 2} and H{sub {infinity}} control syntheses and gives a powerful multi-objectives design addressed by the linear matrix inequalities (LMI) technique. To demonstrate the effectiveness of the proposed method a four-area restructured power system is considered as a test system under different operating conditions. The simulation results with the proposed controller are shown to maintain robust performance in the presence of SMES unit in two areas at power system and without SMES unit in any of the areas. Analysis reveals that the proposed control strategy with considering SMES unit improves significantly the dynamical performances of system such as settling time and overshoot against parametric uncertainties for a wide range of area load demands and disturbances in either of the areas even in the presence of system nonlinearities. (author)

  9. An Efficient Subcarrier and Power Allocation Algorithm for Dual-Service Provisioning in OFDMA Based WiBro Systems

    DEFF Research Database (Denmark)

    Anas, Mohmmad; Kim, Kanghee; Ahn, Jee Hwan;

    2005-01-01

    This paper investigates the problem of resource allocation for quality of service (QoS) support in Orthogonal Frequency Division Multiple Access (OFDMA) based WiBro systems. We identify the key QoS parameters as data rate and bit error rate (BER), which are used to determine the individual traffic...... demands. We propose a resource allocation algorithm to provide dual-service, Guaranteed Performance (GP) and Best Effort (BE) differentiated on the basis of required QoS. Subcarrier assignment and power allocation are carried out sequentially to reduce the complexity, and GP users are given priority over...... BE users in assigning subcarrier and allocating power. We present the simulation results of the proposed algorithms applied to frequency selective Rayleigh fading channel with additive white Gaussian noise (AWGN) and OFDMA....

  10. A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

    Science.gov (United States)

    Aloulou, R.; De Peslouan, P.-O. Lucas; Mnif, H.; Alicalapa, F.; Luk, J. D. Lan Sun; Loulou, M.

    2016-05-01

    Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm2. Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.

  11. Transient Stability Enhancement of a Multi-Machine System using Particle Swarm Optimization based Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    Poonam Singhal

    2014-07-01

    Full Text Available In this paper an attempt has beenmade to investigate the transient stability enhancement of both SMIB and Multi-machine system using UPFC controller tuned by Particle Swarm Optimization. Power injection modelfor a series voltage source of UPFC has been implemented to replace UPFC by equivalent admittance. The admittance matrix of the power system is then modified according to the power injection model of UPFC. To mitigate the power oscillations in the system, the required amount of series voltage injected by UPFC controller has been computed in order to damp inter area & local mode of oscillations in multi-machine system.

  12. Development of integrity evaluation technology for pressurized components in nuclear power plant and IT based integrity evaluation system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Choi, Jae Boong; Shim, Do Jun [Sungkyunkwan Univ., Seoul (Korea, Republic of)] (and others)

    2004-02-15

    The objective of this research is to develop on efficient integrity evaluation technology and to investigate the applicability of the newly-developed technology such as internet-based cyber platform etc. to Nuclear Power Plant(NPP) components. The development of an efficient structural integrity evaluation system is necessary for safe operation of NPP as the increase of operating periods. Moreover, material test data as well as emerging structural integrity assessment technology are also needed for the evaluation of aged components. The following five topics are covered in this project: development of the wall-thinning evaluation program for nuclear piping; development of structural integrity evaluation criteria for steam generator tubes with cracks of various shape; development of fatigue life evaluation system for major components of NPP; ingegration of internet-based cyber platform and integrity evaluation program for primary components of NPP; effects of aging on strength of dissimilar welds.

  13. Implementation of a Sage-Based Stirling Model Into a System-Level Numerical Model of the Fission Power System Technology Demonstration Unit

    Science.gov (United States)

    Briggs, Maxwell H.

    2011-01-01

    The Fission Power System (FPS) project is developing a Technology Demonstration Unit (TDU) to verify the performance and functionality of a subscale version of the FPS reference concept in a relevant environment, and to verify component and system models. As hardware is developed for the TDU, component and system models must be refined to include the details of specific component designs. This paper describes the development of a Sage-based pseudo-steady-state Stirling convertor model and its implementation into a system-level model of the TDU.

  14. A distributed simulation based approach for detailed and decentralized power system transient stability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, S.; Kouhsari, S.M. [Department of Electrical Engineering, Amirkabir University of Technology (AUT), 424 Hafez Avenue, Tehran 15875-4413 (Iran)

    2007-04-15

    This paper presents a distributed computing approach for piecewise transient stability (T/S) analysis of large-scale electrical networks using Diakoptics and large change sensitivity (LCS) concepts. Detailed T/S analysis in a secure and federative manner based on geographically decomposition using local computational resources is the greatest benefit realized by this method of analysis. In this way, with the minimum communications between subnetworks the same results as the conventional untorn T/S analysis can be achieved. Since the bottleneck in distributed computation is low speed network communication, a new latency exploitation technique is introduced for numerically solving system differential equations. The technique uses different step size in each subnetwork to decrease the number of numerical operations and data communications for a given total simulation time. The proposed distributed T/S method is implemented successfully across computer networks and its performance is studied using a 14 bus IEEE test system and some various large-scale networks up to 3000 buses. The presented results are compared with those obtained from conventional untorn T/S simulation. (author)

  15. Real-Time Wavelet-Based Coordinated Control of Hybrid Energy Storage Systems for Denoising and Flattening Wind Power Output

    Directory of Open Access Journals (Sweden)

    Tran Thai Trung

    2014-10-01

    Full Text Available Since the penetration level of wind energy is continuously increasing, the negative impact caused by the fluctuation of wind power output needs to be carefully managed. This paper proposes a novel real-time coordinated control algorithm based on a wavelet transform to mitigate both short-term and long-term fluctuations by using a hybrid energy storage system (HESS. The short-term fluctuation is eliminated by using an electric double-layer capacitor (EDLC, while the wind-HESS system output is kept constant during each 10-min period by a Ni-MH battery (NB. State-of-charge (SOC control strategies for both EDLC and NB are proposed to maintain the SOC level of storage within safe operating limits. A ramp rate limitation (RRL requirement is also considered in the proposed algorithm. The effectiveness of the proposed algorithm has been tested by using real time simulation. The simulation model of the wind-HESS system is developed in the real-time digital simulator (RTDS/RSCAD environment. The proposed algorithm is also implemented as a user defined model of the RSCAD. The simulation results demonstrate that the HESS with the proposed control algorithm can indeed assist in dealing with the variation of wind power generation. Moreover, the proposed method shows better performance in smoothing out the fluctuation and managing the SOC of battery and EDLC than the simple moving average (SMA based method.

  16. Design of test system for aircraft power system based on Labwindows/CVI%基于Labwindows/CVI某型飞机电源检测系统设计

    Institute of Scientific and Technical Information of China (English)

    范雪扬; 高玉章; 宋伟健

    2013-01-01

    针对维修保障中需要对某型飞机电源系统进行快速检测这一需求,设计了一种基于Labwindows/CVI的飞机电源检测系统,用来实现对该系统相关电气参数的准确测量.实际应用表明,该系统具有运行稳定可靠、操作方便、维护简单的特点,检测结果准确可靠,能够满足该型飞机电源系统的维护保障需要.%Aim at the requirement of the fast test for the aircraft power system, the design of aircraft power test system based on Labwindows/CVI is introduced in this paper. The system can realize the exact test results for the electric parameters of the aircraft power system. The result shows that the system has good and reliable performance for measurement of parameters test, and can satisfy the requirement of the power system for maintenance support.

  17. Demonstration of a Novel Synchrophasor-based Situational Awareness System: Wide Area Power System Visualization, On-line Event Replay and Early Warning of Grid Problems

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, A.

    2012-12-31

    Since the large North Eastern power system blackout on August 14, 2003, U.S. electric utilities have spent lot of effort on preventing power system cascading outages. Two of the main causes of the August 14, 2003 blackout were inadequate situational awareness and inadequate operator training In addition to the enhancements of the infrastructure of the interconnected power systems, more research and development of advanced power system applications are required for improving the wide-area security monitoring, operation and planning in order to prevent large- scale cascading outages of interconnected power systems. It is critically important for improving the wide-area situation awareness of the operators or operational engineers and regional reliability coordinators of large interconnected systems. With the installation of large number of phasor measurement units (PMU) and the related communication infrastructure, it will be possible to improve the operators’ situation awareness and to quickly identify the sequence of events during a large system disturbance for the post-event analysis using the real-time or historical synchrophasor data. The purpose of this project was to develop and demonstrate a novel synchrophasor-based comprehensive situational awareness system for control centers of power transmission systems. The developed system named WASA (Wide Area Situation Awareness) is intended to improve situational awareness at control centers of the power system operators and regional reliability coordinators. It consists of following main software modules: • Wide-area visualizations of real-time frequency, voltage, and phase angle measurements and their contour displays for security monitoring. • Online detection and location of a major event (location, time, size, and type, such as generator or line outage). • Near-real-time event replay (in seconds) after a major event occurs. • Early warning of potential wide-area stability problems. The system has been

  18. POWER SYSTEMS DEVELOPMENT FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-11-01

    This report discusses test campaign GCT4 of the Kellogg Brown & Root, Inc. (KBR) transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT4. GCT4 was planned as a 250-hour test run to continue characterization of the transport reactor using a blend of several Powder River Basin (PRB) coals and Bucyrus limestone from Ohio. The primary test objectives were: Operational Stability--Characterize reactor loop and PCD operations with short-term tests by varying coal-feed rate, air/coal ratio, riser velocity, solids-circulation rate, system pressure, and air distribution. Secondary objectives included the following: Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. Effects of Reactor Conditions on Synthesis Gas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids-circulation rate, and reactor temperature on CO/CO{sub 2} ratio, synthesis gas Lower Heating Value (LHV), carbon conversion, and cold and hot gas efficiencies. Research Triangle Institute (RTI) Direct Sulfur Recovery Process (DSRP) Testing--Provide syngas in support of the DSRP commissioning. Loop Seal Operations--Optimize loop seal operations and investigate increases to previously achieved maximum solids-circulation rate.

  19. Evaluation of the operational cost savings potential from a D-CHP system based on a monthly power-to-heat ratio analysis

    OpenAIRE

    Alta Knizley; Pedro J. Mago; James Tobermann

    2015-01-01

    This paper focuses on the analysis of a combined heat and power (CHP) system utilizing two power generation units operating simultaneously under differing operational strategies (D-CHP) on the basis of operational cost savings. A cost optimization metric, based on the facility monthly power-to-heat ratio (PHR), is presented in this paper. The PHR is defined as the ratio between the facility electric load and thermal load. Previous work in this field has suggested that D-CHP system performance...

  20. Potential Environmental Impacts of Hydrogen-based Transportation and Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Grieb, Thomas M; Mills, W B; Jacobson, Mark Z; Summers, Karen V; Crossan, A Brook

    2010-12-31

    Hydrogen (H2) offers advantages as an energy carrier: minimal discharge of pollutants, production from multiple sources, increased thermodynamic efficiencies compared to fossil fuels, and reduced dependence on foreign oil. However, potential impacts from the H2 generation processes, transport and distribution of H2, and releases of H2 into the atmosphere have been proposed. The goal of this project was to analyze the effects of emissions of hydrogen, the six criteria pollutants and greenhouse gases on climate, human health, materials and structures. This project was part of a larger effort by DOE to assess the life-cycle costs and benefits and environmental impacts to inform decisions regarding future hydrogen research. Technical Approach: A modeling approach was developed and used to evaluate the potential environmental effects associated with the conversion of the on-road vehicle fleet from fossil-fuel vehicles to hydrogen fuel cell vehicles. GATOR-GCMOM was the primary tool used to predict atmospheric concentrations of gases and aerosols for selected scenarios. This model accounts for all feedbacks among major atmospheric processes based on first principles. The future scenarios and the emission rates selected for this analysis of hydrogen environmental effects are based on the scenarios developed by IPCC. The scenarios selected for the model simulations are a 2000 and 2050 A1B base cases, and a 2050 A1B case with hydrogen fuel cell vehicles (HFCVs). The hydrogen fuel cell scenario assumed conversion of 90% of fossil-fuel on-road vehicles (FFOV) in developed countries and 45% of FFOVs vehicles in other countries to HFCVs, with the H2 produced by steam-reforming of natural gas (SHFCVs). Simulations were conducted to examine the effect of converting the world's FFOVs to HFCVs, where the H2 is produced by wind-powered electrolysis (WHFCVs). In all scenarios a 3% leakage of H2 consumed was assumed. Two new models were developed that provide the ability to

  1. Potential Environmental Impacts of Hydrogen-based Transportation and Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Grieb, Thomas M.; Mills, W. B.; Jacobson, Mark Z.; Summers, Karen V.; Crossan, A. Brook

    2010-12-31

    Hydrogen (H2) offers advantages as an energy carrier: minimal discharge of pollutants, production from multiple sources, increased thermodynamic efficiencies compared to fossil fuels, and reduced dependence on foreign oil. However, potential impacts from the H2 generation processes, transport and distribution of H2, and releases of H2 into the atmosphere have been proposed. The goal of this project was to analyze the effects of emissions of hydrogen, the six criteria pollutants and greenhouse gases on climate, human health, materials and structures. This project was part of a larger effort by DOE to assess the life-cycle costs and benefits and environmental impacts to inform decisions regarding future hydrogen research. Technical Approach: A modeling approach was developed and used to evaluate the potential environmental effects associated with the conversion of the on-road vehicle fleet from fossil-fuel vehicles to hydrogen fuel cell vehicles. GATOR-GCMOM was the primary tool used to predict atmospheric concentrations of gases and aerosols for selected scenarios. This model accounts for all feedbacks among major atmospheric processes based on first principles. The future scenarios and the emission rates selected for this analysis of hydrogen environmental effects are based on the scenarios developed by IPCC. The scenarios selected for the model simulations are a 2000 and 2050 A1B base cases, and a 2050 A1B case with hydrogen fuel cell vehicles (HFCVs). The hydrogen fuel cell scenario assumed conversion of 90% of fossil-fuel on-road vehicles (FFOV) in developed countries and 45% of FFOVs vehicles in other countries to HFCVs, with the H2 produced by steam-reforming of natural gas (SHFCVs). Simulations were conducted to examine the effect of converting the world’s FFOVs to HFCVs, where the H2 is produced by wind-powered electrolysis (WHFCVs). In all scenarios a 3% leakage of H2 consumed was assumed. Two new models were developed that provide the ability to

  2. Potential Environmental Impacts of Hydrogen-based Transportation and Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Grieb, Thomas M; Mills, W B; Jacobson, Mark Z; Summers, Karen V; Crossan, A Brook

    2010-12-31

    Hydrogen (H2) offers advantages as an energy carrier: minimal discharge of pollutants, production from multiple sources, increased thermodynamic efficiencies compared to fossil fuels, and reduced dependence on foreign oil. However, potential impacts from the H2 generation processes, transport and distribution of H2, and releases of H2 into the atmosphere have been proposed. The goal of this project was to analyze the effects of emissions of hydrogen, the six criteria pollutants and greenhouse gases on climate, human health, materials and structures. This project was part of a larger effort by DOE to assess the life-cycle costs and benefits and environmental impacts to inform decisions regarding future hydrogen research. Technical Approach: A modeling approach was developed and used to evaluate the potential environmental effects associated with the conversion of the on-road vehicle fleet from fossil-fuel vehicles to hydrogen fuel cell vehicles. GATOR-GCMOM was the primary tool used to predict atmospheric concentrations of gases and aerosols for selected scenarios. This model accounts for all feedbacks among major atmospheric processes based on first principles. The future scenarios and the emission rates selected for this analysis of hydrogen environmental effects are based on the scenarios developed by IPCC. The scenarios selected for the model simulations are a 2000 and 2050 A1B base cases, and a 2050 A1B case with hydrogen fuel cell vehicles (HFCVs). The hydrogen fuel cell scenario assumed conversion of 90% of fossil-fuel on-road vehicles (FFOV) in developed countries and 45% of FFOVs vehicles in other countries to HFCVs, with the H2 produced by steam-reforming of natural gas (SHFCVs). Simulations were conducted to examine the effect of converting the world's FFOVs to HFCVs, where the H2 is produced by wind-powered electrolysis (WHFCVs). In all scenarios a 3% leakage of H2 consumed was assumed. Two new models were developed that provide the ability to

  3. A Real-time Video Monitoring System of Mobile Terminals Based on Android Platform: A Case Study of Electric Power Systems

    Directory of Open Access Journals (Sweden)

    Songchun Gong

    2013-03-01

    Full Text Available With the constant improvement of electrical equipment automation level, unattended electric power system node becomes increasingly popular. In addition, because of the ever-increasing industrial demand for electricity, electric power infrastructure becomes larger and larger, equipment and transmission link structure are more and more complex, all kinds of faults emerge one after another and administrative department has more and more urgent demand for electrical inspection personnel in terms of solving problems of various equipments and links. At present, relying on the development of network communication technology, real-time video monitoring system of electric power system is being promoted in a large scale. Real-time video acquisition system of electrical inspection personnel based on mobile terminal will also be applied gradually. A Real-time Video Monitoring System (RVMS of mobile terminals based on Android platform is designed in this study. Through application test of practical environment, the system is able to meet the video data monitoring technique requirements of daily operation and maintenance of electric power system node. Mobile Video Acquisition Terminal (MVAT is able to collect relevant real-time video data in the process of equipment and link faults inspection as well as to provide the video data to remote system maintenance expert, offering data decision to expert in remote real-time solution of equipment failure. All collected video data will be stored in remote system server for establishing a decision database of video information, so as to provide convincing data support for future performance analysis and fault detection of related equipment and link.

  4. Using knowledge based systems for rams analysis and on-line operator support of nuclear power plants

    International Nuclear Information System (INIS)

    With the growing complexity of safety-critical industrial systems there is a need for computer-based tools which integrate different activities related to the layout of such systems and focussing on risk assessment in general. These activities should not only be applicable for early decision taking during the design phase but also allow an advanced maintenance over the whole life of an industrial system and even support on-line operator decision making. Thus such intended activities are embedded in an overall domain description flexible to adapt itself to different situations and extendible for any kind of additional information to attach to. On the other side, however, special applications running in the given domain should react to very specific contexts given by the user and keep their knowledge for themselves. Current research resulted in the development of a methodology (STARS) and an off-line tool (Plant Editor) with which advanced layout techniques, domain administration and extension, and an evaluation of a layout topology are combined. In particular, when using this tool one has a powerful expert system for the design and maintenance of nuclear power plants. In the second part of this paper a tool and methodology (FORMENTOR) for providing on-line decision support to operators is described. (author). 13 refs, 6 figs

  5. Solar thermal power system

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  6. Modeling Power Systems as Complex Adaptive Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  7. Inter-area oscillations in power systems

    CERN Document Server

    Messina, Arturo R

    2009-01-01

    Deals with the application of fresh techniques based on time-frequency system representations and statistical approaches to the study, characterization, and control of nonlinear and non-stationary inter-area oscillations in power systems.

  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. Control interlock and monitoring system for 80 KW IOT based RF power amplifier system at 505.812 MHz for Indus-2

    International Nuclear Information System (INIS)

    For 80 kW inductive output tube (IOT) based RF power amplifier system at 505.812 MHz for Indus-2, a control, interlock and monitoring system is realized. This is to facilitate proper start-up and shutdown of the amplifier system, monitor various parameters to detect any malfunction during its operation and to bring the system in a safe stage, thereby assuring reliable operation of the amplifier system. This high power amplifier system incorporates interlocks such as cooling interlocks, various voltage and current interlocks and time critical RF interlocks. Processing of operation sequence, cooling interlocks and various voltage and current interlocks have been realized by using Siemens make S7-CPU-315-2DP (CPU) based programmable logic controller (PLC) system. While time critical or fast interlocks have been realized by using Siemens make FPGA based Boolean Co-processor FM-352-5 which operates in standalone mode. Siemens make operating panel OP277 6'' is being used as a human machine interface (HMI) device for command, data, alarm generation and process parameter monitoring. (author)

  10. Multi-objective based on parallel vector evaluated particle swarm optimization for optimal steady-state performance of power systems

    DEFF Research Database (Denmark)

    Vlachogiannis, Ioannis (John); Lee, K Y

    2009-01-01

    of steady-state of power systems. Specifically, reactive power control is formulated as a multi-objective optimization problem and solved using the parallel VEPSO algorithm. The results on the IEEE 30-bus test system are compared with those given by another multi-objective evolutionary technique...

  11. Power Electronics Control of Wind Energy in Distributed Power System

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  12. Coordinated Control of a DFIG-Based Wind-Power Generation System with SGSC under Distorted Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Aolin Liu

    2013-05-01

    Full Text Available This paper presents a coordinated control method for a doubly-fed induction generator (DFIG-based wind-power generation system with a series grid-side converter (SGSC under distorted grid voltage conditions. The detailed mathematical models of the DFIG system with SGSC are developed in the multiple synchronous rotating reference frames. In order to counteract the adverse effects of the voltage harmonics upon the DFIG, the SGSC generates series compensation control voltages to keep the stator voltage sinusoidal and symmetrical, which allows the use of the conventional vector control strategy for the rotor-side converter (RSC, regardless of grid voltage harmonics. Meanwhile, two control targets for the parallel grid-side converter (PGSC are identified, including eliminating the oscillations in total active and reactive power entering the grid or suppressing the fifth- and seventh-order harmonic currents injected to the grid. Furthermore, the respective PI-R controller in the positive synchronous reference frame for the SGSC voltage control and PGSC current control have been developed to achieve precise and rapid regulation of the corresponding components. Finally, the proposed coordinated control strategy has been fully validated by the simulation results of a 2 MW DFIG-based wind turbine with SGSC under distorted grid voltage conditions.

  13. Vehicle-to-Grid Power in Danish Electric Power Systems

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2009-01-01

    The integration of renewable energy systems is often constrained by the variable nature of their output. This demands for the services of storing the electricity generated from most of the renewable energy sources. Vehicle-to-grid (V2G) power could use the inherent energy storage of electric...... vehicles and its quick response time to balance and stabilize a power system with fluctuating power. This paper outlines the use of battery electric vehicles in supporting large-scale integration of renewable energy in the Danish electric power systems. The reserve power requirements for a high renewable...... energy penetration could be met by an amount of V2G based electric vehicles less than 10% of the total vehicle need in Denmark. The participation of electric vehicle in ancillary services would earn significant revenues to the vehicle owner. The power balancing services of electric vehicles...

  14. A High Performance PSO-Based Global MPP Tracker for a PV Power Generation System

    OpenAIRE

    Kuei-Hsiang Chao

    2015-01-01

    This paper aims to present an improved version of a typical particle swarm optimization (PSO) algorithm, such that the global maximum power point (MPP) on a P-V characteristic curve with multiple peaks can be located in an efficient and precise manner for a photovoltaic module array. A series of instrumental measurements are conducted on variously configured arrays built with SANYO HIP2717 PV modules, either unshaded, partially shaded, or malfunctioning, as the building blocks. There appear t...

  15. Potential impacts of wind power on power system transient stability

    Energy Technology Data Exchange (ETDEWEB)

    Slootweg, J.G.; Kling, W.L. [Delft Univ. of Technology (Netherlands). Electrical Power Systems Laboratory

    2002-07-01

    Increasingly, wind turbines are introduced in electrical power systems in order to reduce the adverse environmental impact of conventional electrical power generation. Wind turbines are normally not based on a conventional grid coupled synchronous generator, as is the case with most other types of generation. Instead, squirrel cage induction generators are used, or generators that are controlled by power electronic converters. As a result, wind turbines interact with the power system in a way that differs from conventional generators. Therefore, the dynamic behavior of a power system changes when the wind energy penetration increases. In the paper, the potential impacts of wind power on power system transient stability are investigated, using a dynamic model of a widely used representative test system. First, the typical behavior of each of the three mast important contemporary wind turbine concepts is analyzed. Then, the impact of wind turbines on voltage stability, frequency drop after disconnection of a generator and damping of synchronous generator rotor speed oscillations is investigated. From the results, it can be concluded that the impact of wind power on power system transient stability varies much when either constant and variable speed wind turbines are used. Both have specific advantages and disadvantages, depending on the event being investigated.

  16. DS-CDMA Cellular Systems Performance with Base Station Assignment, Power Control Error and Beamforming over Multipath Fading

    Directory of Open Access Journals (Sweden)

    Mohamad Dosaranian Moghadam

    2011-01-01

    Full Text Available The interference reduction capability of antenna arrays, base station assignment and the power controlalgorithms have been considered separately as means to increase the capacity in wireless communicationnetworks. In this paper, we propose base station assignment method based on minimizing the transmitterpower (BSA-MTP technique in a direct sequence-code division multiple access (DS-CDMA receiver inthe presence of frequency-selective Rayleigh fading and power control error (PCE. This receiverconsists of constrained least mean squared (CLMS algorithm, matched filter (MF, and maximal ratiocombining (MRC in three stages. Also, we present switched-beam (SB technique in the first stage of theRAKE receiver for enhancing signal to interference plus noise ratio (SINR in DS-CDMA cellularsystems. The simulation results indicate that BSA-MTP technique can significantly improve the networkbit error rate (BER in comparison with the conventional case. Finally, we discuss on three parameters ofthe PCE, number of resolvable paths, and channel propagation conditions (path-loss exponent andshadowing and their effects on capacity of the system via some computer simulations.

  17. NB Power Transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, J. [NB Power Transmission, Fredericton, NB (Canada)

    2006-07-01

    The NB Power Transmission System operates 6700 km of transmission lines having voltages of 69 kV, 138 kV, 230 kV, and 345 kV. The history of lightning protection on this transmission system was presented. Lightning protection with shield wires has been applied selectively on the 69 kV and 138 kV lines and has been applied to all lines in the 230 kV and 345 kV range. Beginning in 2000, line arresters were installed on selected 69 kV and 138 kV lines. It was noted that although overhead shield wires are commonly installed to capture lightning strikes and shield the conductors, problems can occur if the electrical flashover of insulators result in a line to ground fault. Good grounding is needed to ensure that lightning enters the ground from the tower. The new approach is to install line arresters on structures without overhead shield wires. Line arresters are surge arresters applied in parallel with the insulator string. This new line arrester technology was tested by installing nearly 1200 arresters in the Saint John area. This paper described the reasons for choosing line arresters over shield wires and presented the methods of installation. The problems and failure rates of the installed line arresters were presented along with solutions, including solutions to protect lines against lightning in areas with heavy icing. Recommendations for future research into the use, application and development of line arresters were also presented. tabs., figs.

  18. Design of a Single Input Fuzzy Logic Controller Based SVC for Dynamic Performance Enhancement of Power Systems

    Directory of Open Access Journals (Sweden)

    DR.D. PADMA SUBRAMANIAN

    2014-10-01

    Full Text Available This paper presents a design of a Single Input Fuzzy Logic Controller (SFLC based Static VAR Compensator (SVC for Dynamic performance enhancement of power systems. The SFLC uses only one input which is the signed distance and has the advantage of reduced number of rules. Improvement of dynamic response by the controller is illustrated in a bifurcation perspective. Bifurcation diagrams of steady state as well as periodic solutions are constructed using continuation method. From the bifurcation diagrams, the existence of various bifurcation points such as, unstable Hopf bifurcation (UHB, stable Hopf bifurcation (SHB, saddle node bifurcation (SNB and period doubling bifurcation (PDB are identified. With the use of tools of nonlinear dynamics, voltage collapse points, and chaotic solutions due to period doublings are unearthed. The effectiveness of the SFL controller over the conventional controller for SVC in delaying the incidence of Hopf bifurcation (HBF, SNB and hence increasing the loadability limit is illustrated for the test system.

  19. Design and implementation of channel estimation for low-voltage power line communication systems based on OFDM

    Institute of Scientific and Technical Information of China (English)

    Zhao Huidong; Hei Yong; Qiao Shushan; Ye Tianchun

    2012-01-01

    An optimized channel estimation algorithm based on a time-spread structure in OFDM low-voltage power line communication (PLC) systems is proposed to achieve a lower bit error rate (BER).This paper optimizes the best maximum multi-path delay of the linear minimum mean square error (LMMSE) algorithm in time-domain spread OFDM systems.Simulation results indicate that the BER of the improved method is lower than that of conventional LMMSE algorithm,especially when the signal-to-noise ratio (SNR) is lower than 0 dB.Both the LMMSE algorithm and the proposed algorithm are implemented and fabricated in CSMC 0.18 μm technology.This paper analyzes and compares the hardware complexity and performance of the two algorithms.Measurements indicate that the proposed channel estimator has better performance than the conventional estimator.

  20. Balancing modern Power System with large scale of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Altin, Müfit; Hansen, Anca Daniela;

    2014-01-01

    Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system...... frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the secure and stable grid operation. To ensure the stable power system operation, the evolving power system has...... to be analysed with improved analytical tools and techniques. This paper proposes techniques for the active power balance control in future power systems with the large scale wind power integration, where power balancing model provides the hour-ahead dispatch plan with reduced planning horizon and the real time...