High efficient torque control of switched reluctance motor taking nonlinear and saturation effects into account

Torque pulsation mechanism and highly nonlinear magnetic characterization of switched reluctance motors (SRM) lead to unfavorable torque ripple and reduce the variety of applications in industry. In this paper, a torque sharing function (TSF) is proposed considering magnetic saturation effects as well as minimizing power loss during the commutation region. Constant torque trajectories are considered in phase currents plane based on nonlinear T-i-theta curves which are obtained by experimental measurements. Optimum points selection on constant torque trajectories are based on improving drive efficiency and minimizing copper loss in each rotor position. This has been achieved by finding the tangent intersection between the constant curves and a circle with minimum radius in entering and outgoing phase currents plane. Compared to conventional TSFs, the resultant reference current from the proposed method has less peak and effective values. Moreover, it also has acceptable performance especially in high torque low speed applications. An experimental four phase 1.6 KW, 8/6 SRM set of magnetic characterization data used to simulate and validate the effectiveness of the proposed method.