Research On Security And Stability Analysis Of Power System Containing Wind Energy

This dissertation researches in the issues re lated to power system security and stability operation of large wind farm groups connected in. The issues mainly discuss the following quesitions:wind farm groups m odeling, the optimal power flow process of system with wind energy, the probability small signal stability analysis in large system. The paper proposes a new m odel which considering wind speed correlation, and a new method for research of system dynamic stability, the results show that the proposed model's calculation accuracy is higher and takes less time for computation.Wind speed correlation of different areas in a wind farm have influences on power system's safe and economic operation. In order to simulate the correlation of wind speed series between different positions, this paper applies Copula function and rank correlation matrix method to measure the coherence of wind speed in a wind far m. It is established the correlated wind sample space. According to active power output characteristics of wind turbines, the polym erization model in a wind far m can be achieved.Monte Carlo optimal power flow is a pplied to IEEE 30 and IEEE 300 bus system that based on the principle of ener gy saving dispatching. The study shows that the accuracy of outputs has been greatly improved as well as reducing the fluctuation ranges in unit generating costs and power flow in branches while considering wind speed polymerization. This approach provides a new method to improve the effectiveness of energy saving dispatching and system operation arrangement, of which the results have been tested effective.Stochastic wind generation brings probabilistic components to eigenvalues analysis when evaluating system dyna mic performance. Since probabilistic eigenvalues of the actual system can not be calculated by Monte Carlo simulation (MCS) for its large scale, this paper proposes G aussian process sim ulation (GPS) instead of MCS to tackle eigenvalue uncertainties of grid connected st ochastic penetration. GPS method is tested on IEEE 39 bus test system and Y unnan Grid in China. The calculation time of probability small signal stability analysis (PSSSA) based on GPS is shorter than th at of MCS. Besides, Com pared with other quasi-Monte Carlo m ethod, GPS has better predictive performance of PSSSA in test syst ems. Considering the number of nodes in second test is so lar ge that MCS can not be used in PSSSA where GPS can, which highlights the importance of GPS in PSSSA.