永磁直驱风电机组变流器低电压穿越控制策略

Low Voltage Ride Through Technology Control Strategy for Direct Drive Permanent Magnet Wind Turbine Converter

针对永磁直驱风力发电机组低电压穿越问题,对传统的变流器控制策略进行改进.机侧变流器控制在传统策略的基础上加装功率控制器,在电压跌落期间,通过功率控制器减小发电机有功电流输出,从而限制发电机输出有功功率,减轻变流器直流侧压力.网侧变流器控制在传统控制策略的基础上增加了对电网无功补偿的控制,在电压跌落期间,根据国家标准对电网注入动态无功电流.仿真结果表明,在不借助传统控制策略在低电压穿越过程使用硬件辅助电路的情况下,能够直接通过改进型变流器控制策略,实现风力发电机组低电压穿越.

In view of the problem of low voltage ride through of permanent magnet direct drive wind power generation system, this paper improves the traditional converter control strategies. The machine side con verter control strategy is adopted to increase power controller on the basis of traditional control strategy During the voltage sag, the generator active current is reducedthrough the power controller. Thereby the output active power of generator is limited and the converter DC side pressure is reduced. The grid side converter control strategy is improved to increase the control of reactive power compensation on the basis of traditional control strategy. During the voltage sag and according to the national standard, the dynamic reactive current is injected into the grid. The simulation shows that, without the aid of traditional control strategies in low voltage ride through hardware assisted circuit used in the process, the realization of wind turbine low voltage ride through can be achieved through the improved control strategy of converter.