说明：  以直驱永磁风力发电系统为研究对象，提出了一种双变化率步长的最大功率跟踪混合控制策略， 并用MATLAB 进行风力发电系统建模与控制策略的仿真验证。
(Taking direct drive permanent magnet wind power generation system as the research object, a hybrid control strategy of maximum power tracking with double rate of change step is proposed, and the modeling and control strategy of wind power generation system are simulated and verified by MATLAB.)