A novel soft-switching converter for switched reluctance motor: analysis, design and experimental results

In order to improve the performance of switched reluctance motor (SRM) drives, some advanced control strategies have been proposed, such as current or flux linkage profile control. To achieve these strategies the motor phase current or phase flux linkage should be controlled precisely. All these require increasing the switching frequency of converter to upgrade stability and dynamic response speed. However, the higher switching frequency may cause the higher switching losses, higher electro-magnetic interference (EMI) and the lower overall efficiency. The use of soft-switching techniques in converter can contribute to reduce them. In this paper a novel soft-switching converter for SRM is presented, which possesses advantages of resonant switch converter (RS), resonant DC link converter (RDCL) and PWM. The addition of external commutating devices to conventional asymmetric bridge converter for SRM substantially reduces switching losses and EMI. The conditions of soft switching are deduced and a practical design consideration is given. Finally, detailed simulation study of the complete system is presented and validated with experimental results