Analysis of Torque and Speed Controller for Five Phase Switched Reluctance Motor

Abstract-The electric drives play a vital role on the productivity to any industry. The application of Switched Reluctance Motor (SRMs) in high performance industry is due to the progress in the motor design and power electronic control technology. The electromagnetic operation of an SRM is achieved by the proper excitation and control. A SRM is characterized by simple features like simple construction, high reliability and low cost. It can be used in the high temperature and hazardous environment applications. Most switched reluctance motors are either 3 phase or 4 phase types with unipolar or half wave electronic drives. The torque ripple must be carefully minimized with proper commutation of the power to each of the stator phase winding. The design of control system for five phase SRM is very complex since it has large torque ripples and non uniform torque at its output. The reduction in torque ripples and speed control requires an effective controller. In this paper the output obtained using PI controller is shown clearly.Here, simulation of the PI based controller for SRM is performed by using MATLAB/simulink. Keywords-switched reluctance motor, proportional integral controller (PI), torque ripple. I.INTRODUCTION A switched reluctance motor is a brushless AC motor which has simple construction and does not require permanent magnet for its operation. Hence it has many advantages over other dc or ac machines. The stator and rotor in SRM have salient poles and the number of poles depends on the number of phases. Normally two stator poles at opposite ends are configured to form one phase. The number of stator poles is always different from that of rotor poles. SR motor has the phase winding on its stator and concentrated windings are used. The windings are inserted into the stator poles and connected in series to form one phase of the motor. SR motor has the phase winding on its stator only and concentrated windings are used. The windings are inserted into the stator poles and connected in series to form one phase of the motor. In a five phase SRM there are five pairs of concentrated windings and each pair of the winding is connected in series to form each phase respectively. The flux linkage, inductance and torque characteristics vary with rotor position (i.e. the relative position of the rotor pole with the stator pole). The flux linkage, inductance and torque characteristics of a SR motor are highly non-linear. Positive torque in a SR motor is available at half the rotor pole pitch. Torque production in an SR motor can be explained based on energy conversion process. When one phase of the motor is energized, energy from the power supply is transferred to the phase winding. Part of the energy, which is also known as the co-energy, is used to produce mechanical movement. Torque produced in this movement is defined as the ratio of change in co-energy to the change in rotor position. In mathematical expression, the torque production process can be expressed as Torque = ΔW′̸ Δθ where W′ is co-energy, θ is rotor position