直驱永磁风电机组低电压穿越的一种控制策略

为提高并网直驱永磁风电机组低电压穿越运行能力,提出一种适用于双PWM变换器并网的永磁直驱风电机组低电压穿越运行的电机侧及电网侧变换器协调控制策略。电网电压跌落时,根据输入电网的电磁功率的变化控制电机侧变换器来限制发电机的电磁功率以平衡输入直流侧电容的功率,稳定直流侧电压;根据电网电压跌落深度控制电网侧变换器,提供一定的无功电流,有利于电网电压稳定与恢复,提高风电机组的低电压穿越能力。仿真结果表明,所提控制方案无需硬件装置,能有效实现永磁直驱风电机组的低电压穿越运行。

A control strategy of low voltage ride-through for permanent magnet direct driven wind turbine

To improve the ability of low voltage ride-through（LVRT） for directly driven wind turbine with permanent magnet synchronous generator（D-PMSG）,a generator-side and grid-side converter coordination control strategy is presented to match back-to-back pulse-width modulation（PWM） converter of D-PMSG for low voltage ride-through.When grid voltage drops,the electromagnetic power of the PMSG is limited under the change of grid-side electromagnetic power to balance the power transferred to the DC-link capacitor and keep stability of the dc converter.According to the degree of grid voltage drop,grid-side converter was controlled to provide reactive current output to keep the grid voltage stability and improve the ability of wind turbine low voltage ride through.The simulation results illustrate that the control strategy can effectively realize LVRT operation of D-PMSG without further hardware apparatus.