MPC Based Position Sensorless SRM Drive with Reduced Torque Ripple for Light Electric Vehicles

Abstract

In this paper, A 12/8, 3-phase, 28 A, 1.25 kW, SRM (Switched Reluctance Motor) is controlled for the application of LEV (Light Electric Vehicle). Asymmetric half-bridge (ASHB) converter is implemented to drive the SRM with a lead-acid battery connected across the DC-link capacitor. An MPC (Model Predictive Control) based sensorless approach is implemented on the target SRM. The estimation of rotor position is executed with the help of the flux-current-position characteristics obtained from the characterization of the machine. The rotor speed is estimated from the instants, as the rotor passes from certain discrete positions and from the estimated rotor speed, the position is estimated and fed to the MPC controller for the switching. The rotor position, phase current and torque are predicted from the analytic and look-up table based models. The cost function is formulated for the torque control of the SRM. The phase current is kept in the limit with two stage cascaded controller, in this work. The regenerative braking feature is added to system, in which a part of energy (kinetic) stored in the moving part of the system is fed back to the input source and thus the range of EV is enhanced in case of practical system.