A fast-built flux-linkage model for switched-reluctance motors

This paper presents a simplified and fast-built model for the analytical representation of the flux linkage of a switched-reluctance motor (SRM). Presently, most conventional methods require numerous flux-linkage-current-position data to build a model; however, this is time-ineffective. In the proposed model, the flux linkage is represented by a limited number of Fourier series terms. The coefficients of the Fourier series are determined by the values of the flux linkage at the aligned position, unaligned position and a midway position. At either the aligned or the midway position, the non-linear relationship between the flux linkage and the phase current is represented by a simplified function, which is derived from a linear relationship — the product of flux linkage and phase current versus phase current — in the saturated region. The proposed model can be built with only five data points of static characteristics, which are simply obtained through finite-element analysis (FEA); this allows for easy implementation and high computational efficiency. The accuracy of the proposed model is verified via comparison to measurements of the steady-state voltage and phase current waveforms of the machine as well as several characteristic curves. The proposed model is shown to have a good degree of accuracy.