定子Crowbar电路模式切换的双馈风力发电机组低电压穿越控制策略

Control strategy of low voltage ride-through for double-fed wind generator with the stator Crowbar circuit mode switch

针对转子Crowbar电路的双馈风力发电机组低电压穿越需要闭锁变流器控制脉冲、直流母线电压波动无法较好地抑制,提出了一种定子Crowbar电路模式切换的双馈风电机组低电压穿越控制方案。电网发生故障时,定子Crowbar电路接入系统,双馈风电机组切换至感应发电机组模式下,转子侧变流器采用转子功率外环控制,网侧变流器采用功率协调控制方案,将机侧功率当作前馈量引入到网侧变流器控制策略中并向电网注入无功功率。仿真分析表明,所提控制方案在确保实现双馈风电机组低电压穿越的同时,能够有效地降低转子暂态电流、稳定直流母线电压,并向电网提供无功功率。

Rotor low-voltage ride through of doubly-fed wind turbine with Crowbar circuit needs to lock the converter control pulses, and DC bus voltage fluctuations can not be effectively reduced. Against the above, this paper proposes a control strategy of doubly-fed wind turbine low-voltage ride through with stator Crowbar circuit mode switching. When the power grid fails, the stator Crowbar circuit is connected to system, double-fed wind turbine is switched to induction generators mode, the rotor-side converter adopts rotor power outer-loop control, grid-side converter uses power coordinated control scheme, the generator side power is taken as feedforward quantity to be introduced grid-side converter control strategy and reactive power is injected into power grid. The simulation shows that the proposed control scheme can ensure the realization of low-voltage ride through of double-fed wind turbine generator, at the same time it can reduce rotor transient current, stabilize DC bus voltage and provide reactive power to the grid.