Simple fault detection and tolerant scheme in VSI-fed switched reluctance motor

The Switched Reluctance Motor (SRM) has magnetic independence of the motor phases, so that it can continue to operate despite partial failures occurring in the motor-converter unit. Such inherent fault-tolerant characteristic is useful to the applications requiring high reliability, such as aircraft. However, on occurrence of fault, speed variation and torque ripple increase and it cause problems in applications. Therefore fault-tolerant SRM drive systems improving these problems are of extreme importance. This paper proposes the novel fault detection/isolation scheme using voltage of lower switches in each phase under the occurrence of inverter faults. It has benefit of simple realization and robustness in load/noise. The SRM operating principle with VSI-fed inverter and the proposed fault detection scheme is analyzed in detail. Also the validity of the proposed method is verified by simulation.