中文摘要：

提出一种＂直流卸荷电路＋定子动态变阻值撬棒保护（stator dynamic series resistor crowbar,SDSRC）＋静止无功补偿器＋网侧无功控制＂的综合控制策略,并从电压跌落程度、功率损耗角度出发,考虑SDSRC适用范围,将控制策略分为两种模式,其中SDSRC取值为动态变阻值,以能更好地适应电压跌落水平的变化,起到提升机组低电压穿越能力和稳定运行能力的作用。在PSCAD平台下构建基于综合控制策略的双馈风电机组模型,通过仿真验证了不同电压跌落下的双馈风电机组低电压穿越能力,以及两种模式的综合控制策略的可行性。研究结果表明,所提方法不仅能有效保护机组直流侧电容和转子变流器,增强机组低电压穿越能力,而且增强了故障穿越后机组和系统运行的稳定性,克服了传统crowbar技术的弊端。

英文摘要：

With the in-depth study on the LVRT technology, the disadvantages of traditional crowbar technology have become increasingly prominent. The doubly-fed induction generator（DFIG） can＇t provide reactive power instead of absorbing it from the system for excitation which can bring about further deterioration, in the meantime the fault current frequency of wind turbine isn＇t 50 Hz, when the rotor converter is short circuited, it also has a great impact on the frequency protection which is based on Fourier algorithm. A integrated control strategy was proposed which can be divided into two different control modes according to the voltage drop levels, and the resistance of stator crowbar is floating with the level of Voltage Dips. The simulation model was build in the PSCAD platform, in which can simulate the capability of the low voltage ride through of DFIG by utilizing the voltage sag generator as well as verify the feasibility of the control strategy in different Voltage Dips, it can not only protect the unit of DC side capacitance and the rotor converter effectively and enhance the capability of low voltage ride through, but also enhance the stability of the unit and system after fault ride-through.And overcomes the disadvantages of traditional crowbar Technology.