为了对故障中各种电气量进行准确仿真分析以揭示隐极同步发电机励磁绕组匝间短路的故障机理,需要准确计算电机的各种参数,尤其是与发生匝间短路的励磁绕组有关的电感参数。从隐极同步电机分布式励磁绕组在各极下的单个同心式线圈出发,应用气隙磁导的概念和谐波分析的方法计算与单个励磁线圈有关的电感参数,并按照故障的励磁绕组的实际连接情况进行叠加,得到了与励磁绕组各回路有关的多回路参数模型。该模型考虑了励磁绕组故障回路产生的各种谐波磁场的作用,并通过具体算例间接说明了其合理性。将该参数模型用于励磁绕组匝间短路故障的多回路计算,计算结果与样机实验吻合,验证了参数模型的准确性。
In order to simulate the electrical states such as currents of stator and rotor windings accurately in fault conditions, and to find out the physical principles behind inter turn short circuits of field windings in non-salient pole synchronous machines, it is necessary to calculate the parameters of the machine accurately, especially the inductances of the filed windings with inter-turn faults. Given that non-salient pole synchronous machines feature distributed field windings, this paper calculates the inductances of single field coils using the harmonics analysis method and air-gap permeance concept, and derives the multiloop parameter model based on the actual connection of the field winding with inter-turn faults. The parameter model considers the harmonics of magnetic field caused by the fault loop in field winding, and is justified by several inductance calculation examples in this paper. Substituting the parameter model into the multi-loop model for inter-turn short circuit faults of field winding, the currents of all the stator and rotor loops in non salient pole synchronous machines are derived. The results coincide well with the experiment results on a model machine. The correctness and accuracy of the parameter model are thus verified.