Switching Signals Analysis for Online Stator Fault Diagnosis in Asymmetrical Six-Phase Induction Motor Drives With Model Predictive Control

This article proposes the use of inverter switching signals in the diagnosis of interturn short circuit faults and high-resistance connections in asymmetrical six-phase induction motor drives using model predictive control. This technique eliminates the use of extra sensors and overcomes the issue related to the current compensation imposed by the control system. The proposed approach consists of extracting the amplitude of the fundamental frequency of the six gate signals of the upper switches of the inverter in real time. These amplitudes provide important indicators for assessing the severity of the fault and locating the faulty phase. Additionally, the occurrence of high-resistance connections is analyzed, demonstrating that it can be differentiated from interturn short circuit faults. The presented experimental results, covering different loads, speeds, and fault severities, confirm and validate the effectiveness of the proposed technique.