Discrete and Parametric Fault Diagnosis of an Inverter-Driven Brushless DC Motor Using a Hybrid Formalism

Abstract

This paper presents a diagnosis approach for inter-turn short circuit faults and open circuit switch faults in a brushless direct current (BLDC) motor driven by a three-phase voltage source inverter taking into account their hybrid behaviour. The diagnosis method consists of a discrete faults diagnosis module and a continuous faults diagnosis module combined by means of a hybrid automaton. The discrete diagnoser constitutes the discrete part of the hybrid automaton. It is designed based on a discrete presentation of the system taking into consideration the nominal and faulty states. On the other hand, continuous fault diagnosis is achieved by a hybrid sliding mode observer based on the Super Twisting algorithm. A Lyapunov based approach is used to address the convergence analysis problem of the hybrid observer. The performance of the proposed approach in detection and isolation of discrete and parametric faults is demonstrated by numerical simulations.