改进型双馈风力发电机最大功率点跟踪策略

针对传统双馈风力发电机最大功率点跟踪极值搜索策略将正弦信号作为搜索信号而很难将正弦信号从总的输出信号中区分出来的问题,提出了一种利用风湍流作为极值搜索信号的改进型最大功率点跟踪策略。该改进策略对叠加风湍流的叶尖速比和功率系数进行傅里叶变换,获得相位差信息,从而确定叶尖速比变化方向,使双馈风力发电机达到最佳运行工作点。仿真结果表明,该改进策略可控制风力发电机转速较好地跟踪风速变化,实现了额定风速以下运行区域的最大风能捕获。

Improved maximum power point tracking strategy of doubly-fed wind generator

In view of problem that traditional extremum seeking strategy of maximum power point tracking of doubly-fed wind generator takes sine signal as seeking signal,and the sine signal is difficult to be distinguished from output signal,the paper proposed an improved maximum power point tracking strategy which uses wind turbulence as extremum seeking signal.The improved strategy makes Fourier transform for blade top speed ration and power coefficient to obtain phase difference information,so as to determine change direction of blade top speed ration to make doubly-fed wind generator reach the best running point.The simulation result shows that the improved strategy can control rotational speed of wind generator to track change of wind speed well and realizes maximum wind energy capturing in running region under rated wind speed.