Study on the protection of asymmetric bridge circuit for switched reluctance motor

There are demands for very large KVA switched reluctance drives (SRD) for many applications. However, one of the key issues is to ensure that the current and voltage capabilities of IGBTs are enough to safely transfer the power from the supply to the SRM. This paper extends the snubber topology of full bridge circuit to the asymmetric bridge circuit of SRDs, proposes and evaluates three different snubber protection circuits which consist of resistance, diode and capacitance (RDC) in order to obtain the most appropriate RDC circuit which can be used in the asymmetric bridge circuit. Both simulation and experiment validate the analyses on a laboratory prototype SRM drive.