Copper Loss and Torque Ripple Reduction in Switched Reluctance Motor Considering Magnetic Saturation Effects

Discrete torque generation mechanism and inherently nonlinear magnetic characterization of switched reluctance motors lead to unacceptable torque ripple and reduce the variety of applications in industry. In this paper, a phase current profiling technique and torque sharing function are proposed considering magnetic saturation effects as well as minimizing power loss during the commutation area between the adjacent phases. Constant torque trajectories are considered in incoming and outgoing phase currents plane based on nonlinear T-i-theta curves which are obtained from experimental measurements. Optimum points on constant torque trajectories are selected based on improving drive efficiency and minimizing copper loss in each rotor position. In order to implement the proposed method, experimental measurements were undertaken to obtain the motor operational characterizations. A modification scheme based on logical rules will be introduced to enhance maximum speed with torque free operation. Experimental and simulation results on four phase, 4Kw 8/6 SRM, validate the effectiveness of the proposed method.