An Efficient Diagnosis Method for Short-circuit Fault of Electrically-excited Double Salient Pole Motor

Inter-turn short circuit in the stator winding is a common fault in electrically-excited double salient pole motors (EE-DSPMs). When the number of turns is small, it is difficult to identify the fault accurately by a single fault characteristic, so it is important to study the operating characteristics of the motor under short circuit faults. This paper firstly analyzes the characteristic signal mechanism when a short-circuit fault occurs according to the structural characteristics of the EE-DSPM based on the winding current and electromagnetic characteristics under two short-circuit faults by a finite element method, and then proposes an efficient diagnosis method for its short-circuit fault. The influence of the armature reaction generated by the short-circuit current on the motor is derived. Finally, a simulation model of the control system of an EE-DSPM is established, and the simulation results verify the effectiveness of the proposed method.

1. Introduction

The inter-turn short circuit of stator's winding [1] is a common fault in electrically-excited double salient pole motors (EE-DSPMs). However, when the number of turns with a short-circuit fault is small, the impact on the motor's magnetic field [2] is also small, making it difficult to accurately identify the fault through a single fault feature [3]. To enhance the diagnosis ability for the short-circuit fault, we need to comprehensively investigate the operating characteristics of the motor with the short-circuit fault.