有铁心永磁直线电机初级匝间短路故障分析

Analysis of Inter-turn Short Circuit Fault in Iron-core Permanent Magnet Linear Machine

在有铁心永磁直线电机(permanent magnet linear machines,PMLM)初级匝间短路故障分析中,对初级短路环电流的分析十分重要。该文提出采用磁动势–气隙磁导模型与电枢绕组故障等效模型结合的解析方法,计算任意初级位置发生的匝间短路故障短路环电流。首先根据永磁、电枢磁动势与开槽情况下的气隙磁导函数分别计算通过短路环的永磁、电枢磁链,然后通过矢量合成法得到短路环中的实际磁链以及瞬时短路电流。基于有限元方法证明解析法的正确性并探究不同短路故障匝数、不同短路故障位置对电机性能如短路环电流、相电流、推力的影响。最后制造一台样机验证有限元分析、解析法计算结果的正确性。

Analyzing the primary inter-turn short circuit ring current in iron-core permanent magnet linear machines(PMLMs)is of significance to the inter-turn short circuit fault analysis.An equivalent armature circuit model combined magnetomotive force-permeance model is proposed to predict the inter-turn short circuit ring current.First,the magnetomotive forces produced by permanent magnets and armature current are multiplied with airgap permeance considering the slotting effect to acquire the airgap flux distribution.The flux linkage in the short circuit ring produced by permanent magnet and armature current is obtained respectively with the knowledge of flux distribution.Then,the flux linkage in the short circuit ring is calculated by vector synthesis method using the former two types of flux linkage.The effectiveness of the proposed method is validated by finite-element analysis(FEA).Furthermore,influences of various turns of short circuit rings and different places of inter-turn short circuit faults on the performance of the machine including shorted current,phase current and force characteristics are investigated based on FEA.Finally,a prototype is manufactured to validate the proposed method and FEA results experimentally.