Energy management system (EMS), known as the brain of power grid, utilizes information flow to control energy flow so as to keep power grid operation efficient and secure. Conventionally, the EMS is a centralized one ...
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With the rapid growth of grid-connected wind power penetration level,it is necessary to study the impacts of wind power on powersystem *** small-signal stability of powersystems with large-scale wind power is explor...
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With the rapid growth of grid-connected wind power penetration level,it is necessary to study the impacts of wind power on powersystem *** small-signal stability of powersystems with large-scale wind power is explored using the eigenvalue analysis method.A prototype sample system,the two-synchronous-generator system with a wind farm,is proposed for theoretical ***,simplified models of wind turbines(WTs)and the corresponding equivalent models of wind farms are *** kinds of typical WT models,i.e.,squirrel cage induction generator,doubly-fed induction generator,and permanent magnet synchronous generator are ***,based on the simplified equivalent models,effects of large-scale wind farms on the electromechanical oscillation modes(EOMs)of synchronous systems are *** results indicate that wind farms of the three kinds of WTs have positive effects on ***,long transmission lines connecting wind farmto the systemmay produce negative effects on the small-signal stability of the system.
The impact of inertia control of doubly-fed induction generator (DFIG) wind turbines on the small-signal stability of systems is studied. Firstly, the principle of DFIG wind turbines offering inertia responses is disc...
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The importance of establishment of the low-carbon power grid index system and its comprehensive evaluation model for the development of the low-carbon power grid is firstly discussed. Based on the concept of life cycl...
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Cascading wind farm trips have brought new challenge to the wind power integration. Traditional reactive power optimization can achieve a desirable control result, but voltage security violation usually happens after ...
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Due to the energy crisis of the next fifty years, an increasing number of large-scale wind farms are integrating into powersystems. Parallel simulation platforms are indispensable to evaluate the effects of wind farm...
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ISBN:
(纸本)9781479936571
Due to the energy crisis of the next fifty years, an increasing number of large-scale wind farms are integrating into powersystems. Parallel simulation platforms are indispensable to evaluate the effects of wind farm integration. A GPU-based parallel simulation platform is constructed in this paper to test the feasibility of simulating integration systems on GPU. By adopting previous research work such as averaged model and improved EMTP algorithm, models and algorithm of the platform are firstly introduced. Then the hardware and software architecture of the platform are put forward, which combine CPU configuration and GPU computing. Finally, a wind farm with different numbers of DFIGs are used to test the performance of the platform. Results show that the platform has excellent accuracy, efficiency and scalability. The work of this paper proves the feasibility to simulate wind farm integrating dynamics adopting GPU and its potential to reach tremendous efficiency and scalability.
China's electrical grid has installed more than 2500 sets of phasor measurement unit (PMU), covering almost all the 500 kV and above and part of the 220 kV substations, which in sure observable of the ultra-high v...
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China's electrical grid has installed more than 2500 sets of phasor measurement unit (PMU), covering almost all the 500 kV and above and part of the 220 kV substations, which in sure observable of the ultra-high voltage power network and provide mass data for system analysis. However, PMU measurements may contain bad data and the precision of measurements especially phase need to be further improved. state estimation is an effective method to deal with data contaminated by noise and bias. Therefore, it's of great significance to study the PMU-only state estimation (POSE) problem. The real number equations based on the rectangular coordinate system and weighted least squares (WLS)algorithm are the general method to solve the POSE problem at present, which need to convert phasors into their real and imaginary parts, thus enlarging the size of the coefficient matrix which decreases the computational efficiency. In this paper, complex number equations for the POSE problem are established and the complex number weighted least squares (CWLS) estimation model is built to solve the equation directly in the complex domain which needs no phasor converting. The error characteristics of PMU measurements in the complex domain are analyzed in depth which give a guidance of choosing weights and illustrate the robustness of the CWLS to phase. Test results demonstrate the contrast analysis between the CWLS and the WLS from the perspectives of estimation time, estimation accuracy and adaptability to different error levels, which shows that the performances of the CWL Sare better than the WLS. The robustness of the CWLS to phase is also showed in the tests.
In the conventional phase-shift control of isolated bidirectional DC-DC converters, the phenomenon of power backflow is quite obvious. General improved phase-shift control methods can reduce the power backflow of the ...
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ISBN:
(纸本)9781479957774
In the conventional phase-shift control of isolated bidirectional DC-DC converters, the phenomenon of power backflow is quite obvious. General improved phase-shift control methods can reduce the power backflow of the input. However, they do not take the power backflow of the output into consideration. In this paper, a novel phase-shift control of isolated bidirectional DC-DC converters for unidirectional power flow is proposed. It can eliminate the power backflows of both the input and the output at the same time. Furthermore, the converters in the proposed phase-shift control can achieve the zero-current switching in the whole power rang. Experimental results from a prototype verify the feasibility and validity of the proposed control method, and show superior performance.
This paper proposes a coordination control strategy of voltage source converter based multi-terminal DC (VSC-MTDC) transmission system for integrating large-scale offshore wind power. Using a typical five-terminal DC ...
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An open architecture of powersystem numerical simulation software is proposed, the interface information between simulation engine and user program is exchanged by Client/Server implementation. The open application p...
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An open architecture of powersystem numerical simulation software is proposed, the interface information between simulation engine and user program is exchanged by Client/Server implementation. The open application program interface is realized by establishing an identical and standardized database(a normalized function interface table) on both sides so that they can understand each other through table searching. The client-side secondary development is not limited to single programming language. Interface software packages have been developed for different programming languages including C++, Matlab and Python. It is verified that the proposed framework has powerful openness as well as flexibility, which will greatly improve the calculating and analyzing capabilities of the powersystem numerical simulation software.
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