Study On Transient Stability Of Power Grid With Large-scale Wind Farms

Large-scale wind farms integrated with the weak grid will change power flow distribution, voltage profile and system rotate intertie, which results in profound influence on transient stability of the power grid. The stability analysis when the power system suffers from large disturbances has become one of hot issues in corresponding filed. Based on the Short-circuit Test Project of the Dispatching Center of Inner Mongolia grid, this paper systematically studies the effects of large-scale wind power on angle transient stability and voltage stability. The main works of this paper can be illustrated as follows:First, this paper establishes wind turbine models used in electromechanical transient simulation of power system, and verifies the accuracy of the equivalent system, and then analysis the influence of wind power on power system transient stability when wind speed varies and fault happens.Second, this paper illustrates the simulation scheme of Inner Mongolia Power Grid Short-circuit Test. The scheme analyzes the influences of the test on Inner Mongolia grid and test region grid in aspects of angle transient stability and voltage transient stability, so confirms the validity of identification of short-cut location.Third, this paper proposes the advice of the optimal curves of low-voltage ride through (LVRT) ability of wind turbines considering practical situations. The paper discusses factors that influence the key issues and corresponding design method to design LVRT curves. WuMeng Region Power Grid in Inner Mongolia is taken as an example, and an optimal design scheme of LVRT is proposed based on simulation.Forth, the methods that can improve the transient stability of wind power system are studied, which include Static Var Compensation device and STATCOM. The simulation results shows STATCOM has better effects on improve the stability of power system.All topics discussed in this paper come from field engineering issues. Corresponding researches is believed to contribute to the development of both wind power and grid in Inner Mongolia grid, and also to promote the development of the new energy industry in China.