A Novel Fault Diagnosis Technique of Inter-turn Short-Circuit Fault for SRM in Current Chopper Mode

The inter-turn short-circuit fault of stator winding is a common failure mode in switched reluctance motors (SRMs), which can severely harm the operation of the motor. In this paper, a novel method for diagnosing the inter-turn short-circuit fault in the current chopping mode is proposed, which is suitable for online monitoring and protection of SRMs. The proposed method achieves a fast response and high sensitivity and can mitigate the interference of load conditions on detection reliability. Moreover, this method is based on phase currents, which does not require additional sensor or detection circuits. Meanwhile, the effects of inter-turn fault location in the stator winding on the motor flux and motor parameters are analyzed in detail through finite element analysis, which is helpful to establish a reliable diagnostics technique for various fault conditions. Experimentations based on an 8/6 four-phase SRM with special windings designed to simulate inter-turn short circuit conditions are conducted, and the results have verified the effectiveness of the proposed method.