Study On Impact Of Wind Farm On Power System Stability

Because of pressure of environment protection and energy resource, Wind energy is developing fastest among all kinds of renewable resources due to its low cost and technical maturity. Wind generation has been an important measure in improving economical operation of power system. In recent years, capacity of wind generators and the scale of wind farm are becoming larger and larger, but the randomicity and intermittence of wind will produce disturbance on power system. Model of wind farm and short-time forecasting of wind speed should be established.Firstly, by combining time series method and artificial neural network(ANN), I studied the short-time forecasting of wind speed. By builting time series method, the proposed method choosed input variables of ANN. By choosing back propagation(BP) and generalized regression neural network(GRNN)to forecast wind speed, I found that effect of choosing GRNN is famous. Short-time forecasting of wind speed is very important to the operation of wind power plants and power systems.Secondly, wind speed, wind generators and wind farm are modeled. Wind generator model includes wind turbine model, transferring structure model and asynchronous generator model. Response of wind generators to four kinds of wind speed is simulated and analyzed. In the course of wind farm modeling, wind distribution Jensen and Lissaman model is established by reason of factor of wind wake effect, a wind farm is calculated, the results show the important role of wind distribution model on large scale wind farm researching. Because the equivalent model of wind farm is built, the complexity of emulation research is reduced, makes analysis large capacity wind farm connected to power grid possibly.In the end, the paper achieves the power flow calculation incorporating wind farm, adopts a method that the alternative iteration of general power flow equations, provides a preparation for steady run of grid-connected asynchronous wind power system. An approach to calculate the penetration of wind farm based on transient stability analysis is presented, and the important factor influencing the interconnection of wind farm with this power system is the wave of frequency.