Diagnosis of multiple open switch faults in three phase voltage source inverter

摘要

Three phase Voltage Source Inverter (VSI) plays an important role in power electronic applications. Many types of faults occur in it which degrades the performance of the VSI. One possible fault in inverter is open circuit transistor fault. Knowledge of fault mode is extremely important to improve performance of VSI. This paper presents a method of open circuit transistor fault diagnosis which is based on combination of diagnostic variable and Fuzzy Logic. This method can detect single as well as multiple open circuit faults. Diagnostic variables are used to identify faulty phase and an average current is used to identify faulty switches. Fuzzy logic is used to improve performance of system under variable load conditions during faulty conditions.