中文摘要：

Crowbar保护是目前大多数双馈风力发电机（doubly fed induction generator,DFIG）的主要保护装置。Crowbar电阻的存在对双馈风力发电机的整个暂态过程产生重要影响。故双馈风力发电机三相短路电流的计算应该纳入Crowbar电阻元件。该文针对含Crowbar电阻的双馈风力发电系统新建其暂态等值电路,分析定子侧等效阻抗对暂态过程的影响,推导定子侧暂态等效阻抗表达式,并在此基础上推导出双馈风力发电机三相短路电流最大值和周期分量有效值的表达式。该文还给出了不同Crowbar电阻值对三相短路电流计算的影响。最后运用PSCAD/EMTDC软件对该文提出的三相短路电流最大值和周期分量有效值计算公式进行了验证。研究表明,该文推导提出的双馈风力发电机三相短路电流周期分量有效值和最大值计算公式准确、方便,对风电场的电气安全设计具有重要意义。

英文摘要：

Crowbar protection is the main protection device of most double fed induction generator（DFIG） at present. The existence of Crowbar resistance has an important influence on the transient process of doubly fed induction generator. So the Crowbar resistance element should be considered in the calculation of three-phase short-circuit current of doubly fed induction generator. The transient equivalent circuit of doubly fed induction generation system with Crowbar resistance was built,the influence of stator side equivalent impedance on the transient process was analyzed,The expression of stator side transient equivalent impedance was derived, and on the basis of this, the expression of the maximum value and the effective value of the periodic component of the three-phase short-circuit current of the doubly fed wind generator was derived. The effects of different Crowbar resistance values on the calculation of three-phase short circuit current were also given. At last, the maximum of three phase short circuit current and the effective value of the periodic component were verified by PSCAD/EMTDC simulation. The effective value and the maximum value of three-phase short current of doubly fed induction generator are accurate and convenient, which is of great significance to the electrical safety design of the wind farm.