Performance improvement of the delta-connected SRM driven by a standard three phase inverter

Asymmetric half bridge (AHB) converter provides flexibility in the control of switched reluctance machine (SRM). However, because of the non-standard structure of the AHB converter, limited volume production leads to high cost of the driving system. Delta-connected SRM with series diodes driven by three phase full-bridge inverter was proposed as an alternative by the researchers. However, the conduction angle of each phase is limited to one-Third of electrical cycle, based on the conventional control method. In this study, an improved switching method is proposed to extend the conduction angle and get higher average torque and lower torque ripple. Finite Element Analysis and circuit simulation were done to prove the concept. The results of SRM performance at different speeds regarding average torque and torque ripple was compared for SRM driven with three phase inverter using the conventional and the proposed switching methods. Finally, the results were also compared with the conventional operation of SRM with AHB converter.