A New Fast Method for Obtaining Flux-Linkage Characteristics of SRM

This paper proposes a new fast method to determine the entire flux-linkage characteristics of a switched reluctance machine (SRM), which are critical for performance estimation and advanced control of the machine. The proposed method mainly consists of two steps, namely, measuring and calculating. In the measuring step, the flux-linkage characteristics of the SRM are measured at four specific rotor positions by a new indirect method without rotor clamping devices and position sensors. The magnetic coupling among phases is considered to improve the accuracy of measurement. In the calculating step, based on the measured results, the analytical expression of the flux-linkage characteristics is proposed, which only needs a few coefficients. With the expression, the flux-linkage characteristics at any rotor position can be calculated. The entire flux-linkage characteristics of a 1-kW three-phase 12/8-pole SRM obtained by the proposed method and traditional rotor clamping method are compared, and a good agreement can be found, which verifies the feasibility and accuracy of the proposed method. Furthermore, with the entire flux-linkage characteristics calculated by the proposed analytical method, the dynamic performances of the SRM prototype under both motoring and generating modes are simulated and compared with those from other methods and experiments, which further verify the accuracy of the proposed method.