机组参与调节的双馈机组低电压穿越综合控制策略

Integrated Control Strategy for Low Voltage Ride Through of DFIG Involved in the Regulation

在分析双馈风电机组低电压穿越技术研究现状及不足的基础上,以提升机组低电压穿越能力和改善故障穿越结束后风电机组的稳定运行能力为出发点,提出了一种机组参与调节的适应电压跌落程度的低电压穿越综合策略。采用卸荷电路和变阻值制动电阻代替传统的Crowbar电路,网侧逆变器根据电网电压跌落程度提供变功率因数无功支持,提高机组在电压跌落结束后的稳定运行能力。采用基于磁控电抗器的动态无功补偿装置进行集中补偿,降低投资成本。构建仿真模型仿真验证了该综合控制策略的正确性与有效性。仿真结果表明该方法可以更好的适应电压跌落程度,实现双馈风电机组的低电压穿越能力,同时还可以增强故障穿越结束后风电机组稳定运行能力。

Based on the analysis of the current situation and the weakness of the low voltage ride through technology of the doubly-fed induction generator, an integrated control strategy that the wind turbine is involved in the regulation is proposed, which can adapt to different Voltage Dips. In the proposed control strategy, the crowbar circuit is replaced by DC-Chopper and the dynamic braking resistor; variable power factor reactive power compensation is provided by the grid side converter based on different Voltage Dips to enhance the stability of the wind turbine after fault ride-through. The dynamic reactive power compensation device-based MCR（MSVC） is used to reduce cost. The model is built to testify the correctness and validity of the proposed control method. Simulation results show that the method better adapts to different Voltage Dips, achieving the capability of low voltage ride through, and enhancing the stability of the unit after fault ride-through in the meanwhile.