双馈风电变流器单Chopper低电压穿越策略测试

Test of Single Chopper Low Voltage Ride-through Strategy for Doubly-fed Induction Generator Converter

低电压故障下的双馈风电机组(DFIG)常利用撬棒等硬件设备来泄放瞬间过高的转子电流,以保护变流器并实现低电压穿越(LVRT)。本文探讨了一种双馈风电变流器单Chopper低电压穿越策略的硬件设计和投切的控制算法,并在1.5 MW双馈风电变流器样机中按照国标要求进行了低电压穿越测试。结果表明,合适的单Chopper低穿组件设计配合合理的投切控制策略可以使双馈风电变流器具备完整的低穿能力,并且能大幅优化双馈变流器的低穿组件硬件成本。

Using Crowbar to relieve instantaneous excessive rotor current is very common in doubly-fed induction generator(DFIG)during low voltage fault of grid.This paper discusses the design of low voltage ride-through(LVRT)Strategy only with chopper in DC-bus side of converter.Both chopper resistance and chopper switching control algorithm are analyzed.LVRT test is carried out in 1.5 MW doubly-fed wind power converter products.The results show that proper design of single chopper LVRT components and reasonable switching control strategy make the doubly-fed wind power converter have complete LVRT capability,and greatly optimize the hardware cost of the LVRT components of the doubly-fed wind turbine.