Analysis And Research On Transient Stability Of Power System Integrated With Wind Power Generation

With the rapid development of wind power in China, large-scale of wind farms integrats into the power system. This kind of new energy power brings benefits to the grid, also many problems for its safety and stable operation at the same time. Wind affected by factors such as climate, natural law, may change along with the seasons. Wind speed may change randomly in a short period of time and may be correlative when the wind farms are adjacent. Wind energy has the characteristics of randomness, intermittent and correlation, thus causing the wind power to be stochastic and difficulty to predict accurately. This kind of power is bound to increase the uncertainty of power system operation, and make the security and stability of power system face new challenges. In order to promote the healthy development of wind power and ensure reliable integration in the process of power grid planning, it is necessary to analysis two major problems involved in the power system from the angle of the grid. They are establishing wind power which considers correlative wind speed, and researching on power system transient stability integrated with wind farms.In dealing with the problem of wind speed correlation, third order polynomial normal transformation method based on probability weighted moments was used to predict the random and correlative wind speed in this paper. To study the uncertainty of power system transient stability integrated with wind power, Kriging surrogate model was proposed. The random and correlative wind speed predicted was regarded as stochastic input. For each input, transient time-domain simulation was performd to obtain the stochastic response. Kriging surrogate model can be established to display the implicit function between stochastic input and response. Compared with Monte Carlo method, Kriging surrogate model can get the response statistics more quickly when the caculation times are the same. The case studying on IEEE 39-bus system verifies the effectiveness, accuracy and efficiency of the method adopted. The case studying on Yunnan power grid system verifies the method’s practicability to the actual system. Meanwhile it shows that the random wind speed can cause uncertainty of the system response and have certain influence on the power system’s safety and stable operation.