双馈风电机组低电压穿越特性的试验研究

Experimental Research on LVRT Capability of DFIG Wind Turbine

低电压穿越能力正逐渐成为大型并网风电机组的必备功能之一,要求风电机组在电网电压跌落发生时保持并网,故障消除后快速恢复正常运行。在分析双馈机组电压跌落特性的基础上,采用了转子主动式Crowbar电路和直流侧卸荷电路相结合的方法来实现双馈风电机组的低电压穿越功能,讨论了具体的低电压穿越控制策略,通过仿真验证了电路结构和控制策略的正确性。在实验室10 kW双馈机组实验平台上,采用电压跌落发生器模拟电网电压跌落故障,进行了电网电压跌落至额定电压20%时不同持续时间的测试,证实了所采用的低电压穿越控制策略的有效性。

Low voltage ride through（LVRT） capability is becoming an essential function for high-power grid connected wind turbines,which requires wind turbine to keep connected with grid during voltage sags and recover fast after clearance of the faults.Based on analysis of voltage sag characteristics for DFIG wind turbine,a method integrating rotor active crowbar and DC-side damp circuit was adopted to implement the LVRT capability of DFIG wind turbine,and the specific LVRT control strategy was discussed,then the correctness of the protection circuit and control strategy was verified by simulation.The experiment test was carried out on 10kW DFIG wind turbine experimental test setup,voltage sag generator was used to simulate grid voltage sag faults drop to 20% of rated voltage with different duration time,and therefore the validity of the LVRT control strategy was confirmed.