Research On Wind Farm Modeling And Simulating

Because of pressure of environment protection and energy resources, 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. Mathematical model of wind generators and wind farm should be established.As the basis of the analysis, 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 and geographic location, different wind speed of 72 wind turbines in a wind farm is calculated, the results show the important role of wind distribution model on large scale wind farm researching. Aggregation arithmetic of electrical parameters of wind farm is designed because simulation of a great deal of asynchronous generators operation could cost so much time. A three-wind –generator wind farm connected to infinite bus is simulated to validate the aggregation arithmetic model. Base on wind distribution and electrical aggregation, arithmetic and flow chart of wind farm simulation is established.A simple wind farm connected to infinite bus is simulated and analyzed, which includes small signal disturbance analysis, transient analysis when wind farm starts to be connected, load fluctuates and fault of line in power system is occurred. Then the system involving DaLi wind farm is introduced to calculate the maximum capacity of wind farm connected to grid by steady analysis and transient analysis.The model of doubly-fed induction generators is established and operation mechanism is analyzed. Characteristics of doubly-fed induction generators and normal asynchronous generators is compared by steady analysis and transient analysis. The results show that doubly-fed induction generators have remarkable role in enhancing wind farm short-circuit capacity ratio and improving power factor.