一种双馈感应风力发电机低电压穿越的控制策略

A Low Voltage Ride-Through of Strategy for Doubly Fed Induction Generator

电网故障时采用传统的双馈感应风力发电机控制方式,发电机定、转子均会出现过电流等一系列问题,并造成电网故障更为严重。为防止上述情况出现,要求风力发电机必须具备低电压穿越能力。本文根据双馈感应风力发电机电网故障时的运行特点,分析并提出了一种新型电网故障时双馈感应风力发电机转子侧变流器的控制策略,改善了双馈发电机定、转子过电流的情况,实现了双馈感应发电机在电网故障时的低电压穿越。在理论分析基础上,建立了双馈感应发电机转子侧低电压控制模型和3kW双馈感应发电机励磁控制的实验系统。实验结果表明,本文提出的控制策略动态响应快,行之有效。

Grid faults cause series of problems for doubly fed induction generator （DFIG） such as over current in both stator and rotor by using traditional DFIG control methods. In order to solve these problems,DFIG needs low voltage rid through （LVRT） ability. Based on the DFIG characteristics during the symmetric grid fault,this paper proposes DFIG rotor side converter LVRT control method to improve the DFIG over current. Based on theoretic analysis,the modes of LVRT control strategy are established. A 3kW DFIG excitation control experimental system is established. The test results prove the LVRT control method of DFIG to be effective.