Rotor-Flux-Based diagnosis method for igbt open-circuits faults in a field-oriented-control induction motor drive

The paper deals with a single-switch IGBT open-circuit faults diagnosis of a two-level voltage inverter supplying an induction motor controlled in a direct rotor field oriented system. The proposed transistor failures diagnostic algorithm is based on an analysis of an estimated rotor flux as well as a measured stator current space vector in a stationary reference frame. The analyzed solution ensures a fast fault detection time, which is shorter than one period of a stator current fundamental harmonic, without regard to a motor drive operation point. In order to prove a full robustness against false alarms and high effectiveness of the proposed fault diagnostic method, experimental tests have been carried out, whose chosen results are presented in this paper.