A Novel High-Accuracy Interturn Fault Diagnosis Technique for Switched Reluctance Motors Based on Inductance Profile and Superposition Principle

Existing fault diagnosis techniques for interturn short circuits (ITSCs) in switched reluctance motors (SRMs) still face several challenges, including limited accuracy and sensitivity, compatibility with different control strategies, and dependence on operating speed and load. This article introduces a novel fault diagnosis technique for the ITSCs in SRMs using the extracted faulty inductance data over the minimum inductance zone (MIZ) using the superposition principle. First, it provides a detailed analysis for the magnetic circuit of SRM considering ITSCs. Second, it introduces the superposition principle to accurately extract the faulty inductance component of faulty coil/pole. Third, it deduces the mathematical formulation to relate the faulty and healthy component of inductances along with their active number of turns. Fourth, in order to improve the accuracy and sensitivity, it defines the proper calculation window (CW) over the MIZ considering the switching angles and the threshold current level. Finally, the experimental results show a maximum reported error of 1.05% over the entire speed range and different fault ratios (0% to 25%) that confirms the high accuracy and high sensitivity for the proposed technique. In addition, the proposed technique features a simple structure; is completely independent of speed, load, and control algorithm; offers a powerful tool for several industrial applications including electric vehicles (EVs).