Sensorless Commutation Angle Control based SRM Drive for Light Electric Vehicle with Regenerative Braking Capability

In this paper, a sensorless based control is implemented on a three phase, 12/8 SRM (Switched Reluctance Motor) for LEV (Light Electric Vehicle) application. The features like simple, rugged and robust construction along with high torque to weight ratio, high starting torque and wide speed-torque characteristics make the SRM suitable candidate for the EV application. The SRM drive is controlled for starting and motoring conditions at different loads under look-up table and advance angle control-based algorithm. The switching logics in each mode are presented in detail in this paper. The problems associated with low current sensing and flux estimation are eliminated here using the phase symmetricity and phase overlapping. The regenerative braking is also implemented on the drive to enhance the range and efficiency of the vehicle in practical case scenario under sensorless operation and a detailed explanation of the switching strategy in the sensorless mode under motoring and regenerative braking conditions is given here.