Performance comparison of a bridge converter and a modified miller converter: Torque ripple minimization in switched reluctance motor

The Switched Reluctance Motor is a simple and robust motor which is having many applications in the fields where varying power and speed ranges are essential. The Switched reluctance motor having no rotor windings and it is free to rotate between the magnetic field produced by the stator poles. The torque is developed by the tendency of the rotor to align with the stator magnetic field. The torque is controlled by the controlled excitation of stator filed windings either by mechanical or electrical means. The turn on time for each stator phase is a crucial part in the motor speed control. Due to the inherent non uniform torque output characteristics a higher torque ripple is present in the motor output unless a torque ripple minimization strategy is used. Various converter circuits are introduced for reducing the torque ripples by the controlled firing of valves. In this paper two of such commonly based methods are studied and compared to find out the best practices among them which favors the maximum torque ripple reduction.