Modelling, diagnosis, and tolerant control of phase‐to‐phase fault in switched reluctance machine

Winding insulation degradation may lead to phase‐to‐phase fault in switched reluctance machines (SRMs). First, the fault modes are described considering the connected sequence of the coils and the fault behaviours are analysed in details. Second, the equivalent circuit of three‐phase windings is represented and the faulty SRM is modelled based on the derived electromechanical equations. Third, the locations of three current sensors are optimised to calculate the incoming line current and outgoing line current of each phase without utilisation of any extra hardware. The phase‐to‐phase fault can be detected and located by monitoring the residuals between the two line currents during motor operation. Forth, to improve the post‐fault operation performance of the motor, a triple closed‐loop control scheme aiming at suppressing the short‐circuit current is conducted by modifying the switching states of power transistors. Finally, simulations and comparative experiments on a three‐phase 12/8 structure SRM validate the effectiveness of the proposed methods.