Reliability evaluation for distribution system considering the correlation of wind turbines

With the development of economy and industry, increasing demand for electric energy and reserves shortage of non-renewable energy become contradictory focus. Meanwhile, climatic problems like global warming are becoming increasingly prominent. Developing new energy sources to replace conventional ones, becomes the best solution of energy and climatic problems. Wind energy is recognized as an ideal renewable energy form due to its merits such as extensive distribution, low cost and mature technology. This paper introduces a reliability evaluation method for distribution system containing wind turbines as distributed generation. Firstly, we sample wind speed per hour by a fitting function of distribution. Then, piecewise function is used to calculate output of each unit. This method takes random energy output of wind power generator into account. By using time varying output and load model, we can simulate the actual situation of distribution system. Also, correlation of wind turbines is introduced into the evaluation. We use correction matrix to modify obtained wind speed sequence. By this correction, the sampled wind speeds of different units could avoid having great differences. This paper use RBTS system to test the method mentioned above. Result shows that because wind sequence reaches median of the vector after correction, system reliability indices have deteriorated.