A Novel Analytical Design Theory for Switched Reluctance Motors Incorporating Nonlinear Characteristics

The inherent nonlinear attribute introduces numerous uncertainties in the design process of switched reluctance motors (SRMs). Thus, in this article, a novel design theory with unambiguous symbols based on the nonlinear characteristic is proposed for SRMs. First, the speed–torque design requirements and the control methods are incorporated into the nonlinear flux linkage model. The operation current is analyzed at knee speed. Equations regarding the structural and winding parameters are deduced from the energy conversion enclosed by the current-flux hysteresis loop. Design parameters such as current density and magnetic flux density are introduced to replace the empirical parameters of electrical load and magnetic load used in the conventional method. This greatly reduces the reliance on the designer’s experience at the initial design stage. Moreover, the internal structural parameters and the winding factors are taken into account in the design equations. Then, the proposed analytical design method is verified by the design of multiple-phase SRMs through finite element analysis. The main factors causing the errors of output torque are analyzed. The proposed method achieves high accuracy while comprehensively incorporating commonly used design parameters. Finally, an SRM is prototyped and tested for experimental validation.