COPPER LOSS MINIMIZATION WITH USING MODIFIED DIRECT TORQUE CONTROL METHOD IN SWITCHED RELUCTANCE MOTOR DRIVES

Abstract

Switched reluctance motors are associated with such advantages as simple and robust structure, high reliability, and low cost. However, the high torque ripple is one of the major problems. Direct torque control (DTC) Method is widely used on ac machines, such as induction motors and permanent magnet motors. Pulsating torque in switched reluctance motors is high because of commutation. Implementation of DTC technique is simple with good accuracy. In this DTC method, switching strategy is modified and the torque ripple is significantly reduced by choosing the proper bandwidth of the output torque. Recently, a number of studies have been conducted on direct torque control for torque ripple reduction in SRM drives. This paper investigates the conventional DTC method from the standpoint of copper losses. In a second stage, an improved DTC method is proposed for reducing copper losses and increasing the SRM drive efficiency. The conventional DTC and the modified methods are finally compared and the simulation results are presented in MATLAB Simulink.