电网故障下双馈风力发电机动态响应分析及LVRT控制

Dynamic Response Analysis on Grid Fault and LVRT Control Strategy for Doubly Fed WTs

馈电机由于其定子与电网直接耦合相连,故而在电网发生故障时,电机转子侧会产生相应的电压和电流冲击,严重影响到风电场的稳定运行。文章首先讨论了故障发生时刻以及切除时刻的动态响应过程,并在此基础上对一种基于Crowbar电路的低电压穿越控制方法进行了在电网故障发生时刻以及故障切除时刻的仿真研究,通过与传统矢量控制在双馈风电系统发生严重电网故障下的对比分析验证了其可行性与正确性。

Since the stator windings of doubly fed induction generator （DFIG） are usually coupled with power grid directly, the surge can be seen in rotor-side currents and voltages upon grid fault, which have seriously affected the stable operation of the wind farms. Firstly, this paper discusses the dynamic response process of DFIG during the moment of grid fault occurrence and recovery. Then on the basis, the low-vohage ride-through（LVRT）strategy based on Crowbar circuit is researched on simulations. The feasibility and correctness of the strategy is verified by comparing with the traditional vector control on the severe fault of DFIG.