Fault Tolerant Control Strategy of SRM Drives

A fault tolerant control strategy of SRM drives is presented. The mean rotor mechanical speed is sustained, under the absence of one motor phase, due to an increase in the electromagnetic torque reference and the consequent increase of the healthy phases current amplitudes. Dynamic problems as excessive pick phase current and electromagnetic torque overshoot, due to the lack of one motor phase, are avoided using appropriate changes in the phase current controller. The adopted SRM control strategy, based on the electromagnetic torque regulation, is clearly explained for normal and faulty operating conditions. Both dynamic operating conditions are analyzed. Time-domain waveforms of the phase currents, power converter supply current, electromagnetic torque and mechanical speed are presented and discussed as well as the spectral analysis of the power converter supply current and electromagnetic torque.