Abstract
A sensorless rotor position measurement method for switched reluctance (SR) motors is presented. The method is based on estimating a particular rotor position on phase by phase basis and measuring flux linkage and current when the estimated position is reached. By comparing the measured flux linkage with the pre-stored flux linkage corresponding to the particular position for the measured current, the angular difference between the estimated position and the particular position can be calculated. The method is applied to two practical systems, the first being a 0.3 kW 10000 rpm 3-phase 6/4 SR motor with a variable load and the second being a 1 kW 1500 rpm 3-phase 12/8 SR motor with a fan load. The paper examines the theoretical stability of the measurement and shows that measurement errors are not compounded and act as variable disturbance to the system.