A Novel and Low Cost Sensorless Controller for SRM Utilizing Linear Equations: Analysis, Design and Construction

Abstract

A new low cost sensorless controller for Switched Reluctance Motor (SRM) is designed and constructed in this paper. In the presented novel technique, the rotor position is obtained from the linear equations of the SRM phase current, flux and rotor position. In other similar strategies, the detection of rotor position requires an expensive, high speed controller component since a complex process and calculations have to be performed. Because of using linear equations in the presented technique, the program used by of the controller is less complex and simpler which causes a low cost, medium frequency controller can drive the SRM easily. A new configuration of MOSFET driving is also introduced in this paper which solves a typical problem of usual converters. In this paper, one phase mathematical model of SRM is explained at the beginning. Then 50 watts 12 by 8 SRM is selected and analyzed by Finite Element Method (FEM) in order to obtain the necessary motor parameters. After that the novel sensorless technique is introduced and designed for the motor. The controller circuit is then constructed and tested in the laboratory. Finally operational results are presented for the motor and controller circuit under different load conditions