变步长爬山法在双馈风力发电系统最大风能跟踪控制中的应用

摘要

变步长爬山法能不依赖风速检测或风机功率—转速特性曲线而实现风力发电系统的最大风能跟踪，具有良好的应用前景。首先根据风机运行特性给出了直流机模拟风机方案，详细论述了变步长爬山法的原理及在双馈风力发电系统中的实现方法。然后将该方法应用于基于定子电压定向的双馈发电机矢量控制策略中，搭建了带直流机模拟风机的双馈风力发电系统实验平台。实验结果验证了在风速变化的情况下系统能自动搜索达到对应风速的最佳转速，实现风机最大风能捕获，并具有对快变风速的响应能力，验证了控制方案的正确性和可行性。%Variable-step Hill Climbing Searching (HCS) can realize Maximum Power Point Tracking (MPPT) of Doubly-Fed Induction Generator (DFIG) wind power generation system without measuring the wind velocity or obtaining the wind turbine’s power-speed curve, and has a brilliant future. This paper firstly proposes a wind turbine imitation method based on its operation characteristics. Then, a DFIG MPPT control strategy based on variable-step HCS is presented. Then the method is applied to the DFIG vector control strategy directed by stator voltage. At last, an experiment platform with DC simulation machine is built. The experiment results show that the proposed variable-step HCS can not only search the optimum speed automatically and realize MPPT, but also has the ability of responding to the polytropic wind. The feasibility and effectiveness of proposed control strategy are validated.