The low voltage ride-through ability of a wind farm has an important effect on the transient stability of a power system. The excitation control principle of a doubly-fed induction generator (DFIG) was analyzed and the vector control strategy of a wind generator was established based on the current decoupling method. Crowbar hysteresis loop protection of the rotor side converter (RSC) and voltage support technology of the grid side converter (GSC) during the fault were also presented. The transient responses of two types of generators of traditional synchronous generators and DFIGs in short- and long-time short-circuit faults were studied and parameters of the converter, which affect performances of a wind generator, were discussed by using PSCAD / EMTDC simulation tool. The results show that the emergency countermeasures for the converter can quickly restore the control ability of the wind turbine, then the voltage can be reconstructed rapidly by adjusting the magnitude and phase angle of the rotor flux vector. In addition, the selection of suitable DC capacitance capacity will enhance the ability of resisting negative sequence current of a GSC during an imbalance fault.%风电场低电压穿越能力对接入系统的暂态稳定性有着重要影响.分析双馈感应风力发电机的励磁控制原理,在此基础上研究风电机组基于电流解耦的矢量控制策略以及故障期间转子侧变流器Crowbar(撬棒)滞环保护方案和网侧变流器的电压支撑技术.运用PSCAD/EMTDC仿真工具研究常规同步发电机和双馈风力发电机2种类型机组在短时间和长时间短路故障时的暂态响应特性,并探讨变流器参数对风电机组性能的影响.结果表明:变流器紧急应对措施可以使风机迅速恢复控制能力,从而通过灵活地调节其转子磁链矢量的幅值和相角使电压快速重建；此外,选择合适的直流侧电容容量将增强不对称故障情况下网侧变流器抵抗负序电流的能力.
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