A Comparative Investigation of Stator Fault Diagnostics in Induction Motors by Multivariable Monitoring and Finite Element Simulations

Fault diagnostics of electrical machines is crucial given their widespread use across various sectors, including industrial settings, power generation, and electrified propulsion such as the aerospace and automotive industries. Amongst all electric motors, 3-phase induction motors (IMs) are the most widely used due to their durability, high efficiency and low maintenance requirements. However, fault diagnostics in 3-phase induction motors remain essential for maintaining operational efficiency, reducing downtime, and preventing damage to the motor from incipient-level faults that can evolve into failure. This research investigates the behaviour of two 3-phase induction motors of the same size and power rating, but with different rotor geometries, experiencing stator inter-turn short circuit (ITSC) faults of varying severity during steadystate operation. The investigation is performed using extensive simulation data from several finite element models (FEM), and a comparative analysis is then conducted to evaluate the diagnostic capabilities of Motor Current Signature Analysis (MCSA), search-coil based air-gap flux monitoring, and torque analysis alongside the unbalanced magnetic pull (UMP).