Comprehensive Evaluation of the Dynamic Performance of a 6/10 SRM for Traction Application in PHEVs

Switched reluctance machine (SRM) has been viewed as a low-cost machine with concentrated windings on the stator and no magnetic source on the rotor. Owing to the higher torque-production capability with lower ripple, an SRM with a higher number of rotor poles is a potential candidate for traction applications in hybrid and plug-in hybrid electric vehicles. However, since external phase commutation and rotor-position detection are necessary to run the SRM, its control can be challenging. In case of an SRM with a higher number of rotor poles, each phase is energized more frequently in one revolution, and the current conduction time is shorter due to the smaller interpolar gap between rotor poles. This paper investigates potential control complexity owing to the higher number of rotor poles, self-starting, and fault tolerance of the machine. A 5-hp drivetrain with a three-phase 6/10 SRM has been developed for traction application. Conventional current and speed controls have been implemented to experimentally evaluate the dynamic performance of the new family of SRMs. It has been shown that the 6/10 SRM is capable of operating even if two of its phases develop a fault. Moreover, the 6/10 SRM is capable of starting by itself with an initial hard alignment when only two phases are operating.