Effect of Eccentricity on the Accuracy of Rotor Position Estimation Techniques in Switched Reluctance Motor Drives

In the present paper, flux-linkage characteristic of one phase of an 8/6 switched reluctance motor (SRM) in a healthy motor and in the same motor with static and dynamic eccentricity is obtained using two dimensional (2D) finite element (FE) analysis and the effect of eccentricity on the accuracy of rotor position estimation is briefly discussed. It has been observed that the eccentricity affects the flux-linkage/ rotor angular position characteristic of the SRM at low currents. This characteristic has an important role in sensorless control scheme of the motor and its variations can reduce the accuracy of position estimation. Accuracy of the methods which use this characteristic at sufficiently high currents is not affected by eccentricity.