Open Switch Fault Diagnosis of Switching Devices in Three Phase VSI

Abstract

Condition-based maintenance of complicated electrical apparatus is a measure issue in the automation industry. Condition-based maintenance includes fault detection, diagnosis, and prognosis of the system. Different techniques are used for fault diagnosis including knowledge-based fault diagnosis, model-based fault diagnosis and pattern recognition based fault diagnosis. This paper presents an open switch fault diagnosis of a three-phase voltage source inverter used to drive the induction motor. The three-phase real-time current is sensed without using an additional sensor and transformed to the d-q plane. The different patterns are observed for the healthy and faulty condition of switching devices. The patterns are observed to diagnose a faulty switch. The real-time results are presented to validate the proposed method. This method is effective and robust.