A sensorless method for determining rotor position for switched reluctance motors

Abstract

This paper presents a new method for providing rotor position measurement indicators for the control of switched reluctance motors (SRM) without the use of optical or magnetic sensors. The method utilises stored information concerning the magnetic characteristics for a motor phase. However, unlike previous methods, the magnetic information is only required for one rotor position and only one position measurement per phase cycle is made. As a result the stored information is relatively small, and the calculation relatively quick such that the sensorless position detection can be executed by the SRM drive controller without necessitating a separate digital processor or extensive additional hardware. The paper fully describes the method and discusses its accuracy and stability. It also describes and presents results from an experimental system used to verify the method.