A new pitch control strategy for variable-speed wind generator

Due to the complexity and non-linearity of the pitch control system, the pitch angle could not be controlled accurately by traditional PI control. To solve the problem, a prediction-correction pitch control strategy is proposed in this paper. The strategy first processes the wind speed by moving average method, and then gets the prediction value of pitch angle by using wind speed-pitch angle curve-fitting method. Based on this, PI control is used to revise the control error further. At last, the performances of the traditional strategy and the improved strategy are compared by simulation. The results show that the improved strategy can decrease the influence of the wind fluctuation on pitch control effectively. So it can improve the performance of wind generator by capturing maximum wind energy in low wind speed and limiting power output of wind generator in high wind speed.