全功率驱动的异步风电机组的控制策略研究

Research on Control Strategy of Induction Generator Wind Turbine Drived by Full Rated Converter

通过全功率PWM变流器并网的笼型异步风力发电机组(the Full Rated Converter Induction Gener-ator,FRC-IG),以其低成本、高可靠性和易维护的特点引起了人们的关注。在分析笼型异步风电机组数学模型的基础上,对全功率PWM变流器的控制策略进行了研究,给出了基于转矩给定的最大功率跟踪控制策略,通过对电磁转矩的调节间接控制发电机转速来跟随最大功率曲线。网侧变流器采用并网电压控制策略,根据并网电压的幅值来调节无功功率抑制电网电压的波动,在保证风电机组安全运行的同时降低了机组并网对电网的影响。仿真结果表明所采用的控制策略能很好地实现风电机组的最大风能跟踪,降低并网点电压波动。在电网电压故障期间,并网电压控制策略还可以有效地提高机组的低电压穿越能力,保障风电机组稳定运行。

Squirrel-cage induction wind turbines connecting the grid with the full rated PWM converter attracted people＇s attention because of the characteristics of low cost,good reliability and easy to maintain.This paper studied the control strategy of the full rated PWM converter based on the analysis of squirrel-cage induction wind turbine mathematical model,presented the strategy of maximum wind energy tracking control by the referenced torque,controlling the generator speed to follow the maximum power curve indirectly through the regulation of the electromagnetic torque.The grid side converter use grid voltage control strategy to suppress the fluctuation of grid voltage by adjusting the reactive power according to the voltage amplitude,reduce the impact to the grid and ensure the safe operation of wind turbine.Simulation results show that the control strategy can be used effectively to achieve the maximum wind power tracking of the wind turbine and reduce the voltage fluctuation.The grid voltage control strategy can improve the capability of low voltage ride through effectively to ensure the stable running of wind turbines as the grid fault.