中文摘要：

为了使双馈异步风机（DFIG）能够更好地参与微电网频率调节并减少有功控制成本,综合考虑风机向微电网输送有功功率和提供备用容量参与系统调频两方面因素,提出了变减载率超速控制法。计及风速出现概率,采用概率加权求和法,考虑减载成本、调频效益和调频恢复成本求解超速控制成本（COC）,得到变减载率曲线。通过对一个含DFIG的微电网系统进行仿真分析,验证所提方法可有效改善微电网频率动态特性,减少风机有功控制成本,有利于微电网的稳定运行。

英文摘要：

In order to obtain better frequency regulation and less the cost of active power control of micro power grid with the doubly fed induction generator（ DFIG） integrated,an approach of probability weighted sum was proposed for variable load shedding ratio over-speed control,considering the active power of the wind turbine to the micro power grid and providing the reserve capacity to participate in the system frequency modulation. Occurrence probability of wind speed,using probability weighted sum method,considering the cost of shedding load,effect of frequency modulation and cost of frequency modulation recovery for the cost of over-speed control（ COC）,then obtain the variable load shedding ratio curve. Through the simulation of a micro power grid system with the DFIG integrated,the proposed method was verified to effectively improved the dynamic characteristics of the micro power grid frequency,and reduced the cost of active power control of the wind turbine. It was beneficial to the stable operation of microgrid.