双馈风力发电机转子匝间短路故障分析

双馈式风力发电机转子绕组发生轻微匝间短路后,该极磁动势将发生变化,气隙磁密分布不再对称,不对称的磁密分布将在定子绕组内感应附加谐波电动势,形成附加的谐波电流.因此,可以通过分析定子绕组的并联支路环流来检测转子绕组匝间短路故障.采用多回路理论,针对一台4极电机进行建模,仿真计算了不同匝数短路故障时的定子一相并联支路的环流,所得结果与理论分析相符,从而验证了所建立模型的正确性.

Characteristic Analysis of DFIG Rotor Winding Inter-turn Short-circuit Fault

When DFIG rotor winding slight inter-turn short circuit occurs,the related magnetomotive force(MMF)changes.Distribution of air-gap flux density is no longer symmetrical,which may induce additional harmonic electromotive force in stator winding,thus additional harmonic current forms.As a result,analyzing the parallel connection branches circular current in stator can detect rotor winding inter-turn short-circuit fault.The simulation for the inter-turn short-circuit of rotor winding on four-pole motor is carried out by multi-loop methods,and the simulation result coincides with the calculated one.So the value of the parallel connection branches circular current of the same phase in stator for different short-circuit turns of rotor winding can be calculated accurately.