应用STATCOM与Crowbar提高风电场低电压穿越能力

摘要

To meet the grid code requirements on wind turbine generators low voltage fault ride through( LVRT) capa-bility ,a control strategy with integrating STATCOM and Crowbar circuit is proposed to keep LVRT capability through an-alyzing the transient of DFIG. STATCOM adopts a constant voltage control strategy, adjusting the amplitude and phase of the AC side output appropriately by constant-voltage control to provide reactive power to recover the system voltage. The switch of crowbar circuit is controlled by the hysteresis of the rotor current or DC voltage to dump the superabundant energy and protect power inverter. Finally, DFIG and LVRT simulation model is established on PSCAD / EMTDC, the result of which shows that the strategy makes LVRT capability available for DFIG under sharp voltage dip case.%为满足并网风电机组在电网电压在一定范围内瞬间跌落时不脱网运行，通过分析DFIG电压跌落时的暂态过程，建立一种基于STATCOM和Crowbar的低电压穿越控制策略。 STATCOM采用恒电压控制策略，适当地调节交流侧输出的幅值和相位，以提供满足系统电压稳定的无功功率；Crowbar电路的投切，对转子电流或直流侧电压滞环比较来控制，以卸荷多余能量并保护变流器，从而实现低电压穿越。最后，在PSCAD/EMTDC平台建立了DFIG的LVRT仿真模型，结果表明：该策略使DFIG在电压跌落较深情况下具备了低电压穿越能力。