Recent developments of fault diagnosis methods for switches in three-phase inverters

The safe operation of inverters is paid much attention recently. This paper presents a survey on existing diagnostic methods for open-switch faults in inverters. These methods are classified into two categories in terms of the measured variables: one is current-based method and the other is voltage-based method. Voltage and current modes under the open-switch fault modes in the inverters of the open-loop V/F controlled induction machine system and the vector controlled permanent magnet synchronous motor system are simulated and analyzed. The principles of each fault diagnosis method are introduced, and these methods are summarized and compared by applicability, complexity, detection time and reliability. And then difficulties and trends of the research on fault diagnosis of inverters are indicated.