Selected Problems of Optimization of a Switched Reluctance Motor for an Electric Vehicle using Analytical Calculations

Abstract

There are several drawbacks when applying switched reluctance motors – torque ripples, small efficiency at high velocity and acoustic noise, which decide about its competitiveness in comparison with other types of electric motors (i.e. induction motor), especially in electric car drive applications. The great advantage is a simple construction and a high reliability. The paper describes a procedure to develop a 6/4 type SRM with the best performances. Some information related to this construction presented in an earlier paper [1] has been taken into account. A gradient optimization procedure has been employed to improve performances of the SRM. The procedure uses a modified version of the analytical model of the SRM described in [2]. The improved model enables estimation in the steady state operation of not only efficiency and torque ripples, but also acoustic noise, and furthermore – takes into account the magnetic non-linearity. The model does not take into account mutual inductances and their influence on optimization results. A simplified solution of the problem has been proposed in the paper. Calculations were performed in MATLAB environment. The solutions were verified by means of FEM analysis. The analytical model of the SRM is described in the first part of the paper. The problem of neglecting mutual inductances in modelling is discussed. Some results of an optimization approach are presented as well.