Performance of diagnosis methods for IGBT open circuit faults in three phase voltage source inverters for AC variable speed drives

Variable speed drives have become industrial standard in many applications. Therefore fault diagnosis of voltage source inverters is becoming more and more important. One possible fault within the inverter is an open circuit transistor fault. An overview of the different strategies to detect this fault is given, including the algorithms used to localize the open transistor. Previous work showed significant differences among the available methods to detect such a fault for a mains side active rectifier. This paper extends the performance evaluation for the inverter connected to the machine with variable stator voltage and frequency. Simulation results are presented. They show the influence of the applied standard field oriented control on the currents during a fault. An experimental setup in the laboratory is used to validate simulation results. Typical detection results are presented including time-to-detection measurements. Robust detection of open transistor faults has been found to be possible