Time- Frequency Domain Based Diagnostics of Stator Faults in Motors Drives via Dispersal Magnetic Field

This study develops a real-time non-invasive discrete wavelet transformation (DWT) based fault diagnosis (FD) method to detect embryonic stator’s turn-to-turn faults (TTF) in direct torque control (DTC) driven induction motor (IM). The FD algorithm is based on decomposing the radiated magnetic flux captured by an external magnetic loop antenna (MLA) in the time-frequency domain in order to capture the fault features. Theoretical analysis of the IM’s radiated flux behavior in the case of TTF and the DTC reaction to it is presented. The FD technique was examined numerically using Finite Elements and tested experimentally.