基于故障等值网络的双馈风电机组三相短路电流计算方法研究

目前关于双馈风电机组短路电流的研究主要基于传统磁链分析方法。提出一种计算双馈风电机组定转子三相短路电流的新方法。首先将发生三相对称短路的故障网络分解为无故障网络和故障附加网络，在此基础上，考虑机端电压相位跳变以及转子侧变流器调控的影响，从功能解耦的角度出发，进一步将故障附加网络分解为定子侧故障附加网络和转子侧故障附加网络。然后利用Laplace变换方法计算两组故障附加网络下的定转子短路电流增量，并推导全电流解析式。仿真及动模实验结果均验证了定转子短路电流表达式的正确性，对于含双馈风电机组的电力系统短路电流计算和继电保护整定意义重大。

Research on calculation method of three-phase short circuit current for doubly-fed wind power generator based on the fault equivalent network

Nowadays research of short-circuit current for doubly-fed wind generation is mainly based on the method of the traditional flux linkage analysis. A novel calculation method of stator and rotor short-circuit current is proposed. The method deals with fault network following a three-phase symmetrical short-circuit fault as superposition of normal operation network and fault superimposed network. On this basis, the influence of the terminal phase jump and the rotor side converter control is considered. And from the perspective of function decoupling, fault superimposed network is further decomposed into the stator side fault superimposed network and the rotor side fault superimposed network. Then the increment of stator and rotor short circuit currents of fault superimposed network is calculated by using Laplace transform method. And the analytical expression of the total current is deduced. Finally, the effectiveness of the expression is proved by the simulation and dynamic model experiment results. It is of great significance for the short circuit current calculation and relay protection setting of the power system with doubly-fed wind power generator. This work is supported by Science and Technology Project of SGCC (No. PD71-15-043), National Basic Research Program of China (973 Program) (No. 2012CB215206), and Fundamental Research Funds for the Chinese Universities (No. 2014ZZD02).