Electromagnetic Performance and Diagnosis of Induction Motors With Stator Interturn Fault

Abstract

Interturn fault (ITF), a common fault type of induction motors, can impact the safe and stable operation of the motor. Variations of magnetic field distribution and short circuit (SC) current were analyzed, and a diagnosis method of ITF was proposed based on the stator current complex component. First, a 1.1 kW squirrel cage induction motor whose stator winding coils were rewound was taken as a prototype. The distributions of magnetic fields before and after the fault were obtained by calculating the finite element model. Based on the simulation and experimental results under no-load, light load, and rated load conditions, the phase current and SC loop current variations were obtained under different fault degrees. Then, the variations of current amplitudes in the faulty phase, nonfaulty phases, and SC loop were analyzed to determine the impact on the operation of the motor caused by the fault. Finally, a diagnosis method of ITF, which uses the current complex component to represent the current variation, was proposed based on the calculation and analysis of faulty-motor current. The results show that this method can diagnose and locate faults effectively, verify the robustness of load variations, and provide a reference for the research on ITF of induction motors.