Power device gate driver circuit with reduced number of isolation transformers for switched reluctance machine drive

The combined asymmetric half-bridge power converter topology is often used to drive switched reluctance machines (SRMs). This letter describes a transformer-isolated power semiconductor gate driver circuit that uses only two transformers to supply all three power devices in a combined asymmetric half bridge with local power supplies and drive signals. Therefore, the entire gate driver circuitry for a six-switch converter driving a four-phase SRM requires only four isolation transformers, thereby reducing cost. Operation of a prototype circuit is demonstrated.