Simple diagnostic technique of a single IGBT open-circuit faults for a SVM-VSI vector controlled induction motor drive

In this paper a simple diagnostic system for a single IGBT open-circuit faults for a two level voltage inverter-fed field oriented controlled induction motor drive was presented. A fault diagnostic procedure is carried out by utilizing an analysis of a stator current vector trajectory in alpha-beta coordinates. An extraction of the failure information is based on monitoring of an angle between the stator current space vector and the alpha axis. Thanks to a diagnostic signal normalization, high robustness to false diagnosis alarms is guaranteed. To confirm the proposed method, simulation results under a wide range working condition of the induction motor drive were presented.