对称电压故障下双馈风力发电机瞬态特性分析

Transient Characteristics Analysis of DFIG-based Wind Turbine Under Symmetrical Voltage Fault

双馈风力发电机遭受电压故障时的瞬态特性分析特别是转子电流的分析已引起广泛关注。因此,该文对双馈感应发电机(doubly fed induction machine,DFIG)的瞬态特性尤其是转子电流进行具有一般意义的分析。为此,该文提出一种基于空间矢量的DFIG瞬态分析方法。基于此,分析双馈风力发电机遭受对称电压故障时DFIG定子磁链动态,转子开路电压动态,尤其是求出精确的转子故障电流解析式。最后,仿真验证上述方法的正确性和转子故障电流解析式的精确性。求出的DFIG转子故障电流解析式都能够精确再现DFIG遭受电压故障后的瞬态行为。

The transient characteristics analysis of DFIG-based wind turbine under voltage fault, especially the rotor current analysis, has attracted wide attention. This paper analyzed the transient characteristics of DFIG, especially the rotor current with a general significance method. Therefore, a transient analysis method based on space vector was proposed.On this basis, the stator flux dynamics and rotor open circuit voltage dynamics of DFIG under symmetrical voltage fault were analyzed, and the accurate analytical expression of rotor fault current was obtained. Finally, the correctness of the above method and the accuracy of the analytical formula of rotor fault current were verified by simulation. The analytical expressions of DFIG rotor fault current can accurately reproduce the transient behavior of DFIG after a voltage fault.