Analytical Inductance Modeling of Segmental Rotor Switched Reluctance Motor with Single-Tooth Windings

The accurate analytical inductance model is an effective tool for performance evaluation and preliminary design of single-tooth winding segmental rotor switched reluctance motors (STSSRMs). Due to the discontinuous rotor structure and the special magnetic circuit, the analytical inductance calculation of the STSSRM is more complicated than that of the conventional SRM, and it is hard to obtain the accurate inductance at each position directly. To solve this issue, in this paper, an accurate and fast analytical approach is proposed to determine the phase inductance of STSSRM at any rotor position. Firstly, with the analysis of the flux line distribution, the flux tube models and the equivalent magnetic circuits at three critical positions are established to calculate the corresponding permeance and inductance parameters. Secondly, according to the proper approximation in a certain region, an additional critical inductance point is obtained to improve the accuracy of the inductance model by utilizing the quadratic interpolation calculation. Furthermore, with the four inductance values at different rotor positions, a third-order Fourier series inductance model is developed for analytical inductance calculation, where high calculation accuracy can be achieved. The effectiveness of the proposed method is verified by finite element simulation and experiment.