基于Crowbar保护的双馈风力发电机低电压控制策略研究

摘要

Aiming at the problems of the DC over-voltage and the dynamic reactive power compensation, which caused by the doubly-fed wind generator switch Crowbar circuit when the grid voltage dips, and basing on the feedback linearization theory, the nonlinear control strategy on grid-side converter is proposed. This paper adopts a coordinated control STATCOM to compensate the dynamic reactive power of the grid. Simulation result shows that, the grid-side nonlinear controller can well restrain the DC over-voltage during the grid voltage dip, and meet the requirements of system reactive power by introducing a STATCOM compensation device. The result also confirms the correctness of the control strategy, which improves the ability of low voltage ride through (LVRT) of the system. This work is supported by National Natural Science Foundation of China (No. 51267001).%针对双馈风力发电机在电压大幅骤降时投入Crowbar电路后引起直流侧过电压和动态无功补偿的问题，基于反馈线性化理论，提出了对网侧变频器进行非线性控制策略。通过协调控制STATCOM对电网进行动态无功补偿。仿真表明：网侧非线性控制器在电压骤降过程中能很好地抑制直流侧过电压；通过引入STATCOM补偿装置，很好地满足系统无功需求，证实了所提出控制策略的正确性，提高了系统的低电压穿越能力。