Enhancing Torque performance with Dual Teeth Switched Reluctance Motor: A Novel Approach

Among the available Electric traction motors, switched reluctance motor (SRM) because of its robustness, simple structure, and magnet-free construction is becoming a potential candidate for Electric vehicle (EV) traction application. However, they possess several drawbacks such as low torque density, high torque ripple, nonlinear characteristics, and complex control. In this paper, a novel design based on the conventional four-phase 8/6 SRM is proposed to enhance torque density. The stator pole of the 8/6 SRM is divided into two parallel split-poles (dual teeth) and correspondingly the number of rotor poles is increased to arrive at the novel 8/22 SRM configuration. A new formula for the design of stator-rotor poles of the novel SRM is introduced. Static analysis (FEA based) has been carried out to determine the torque output. In order to save computation time, a theoretical method based on Equivalent Magnetic Circuit (EMC) model is developed and its accuracy is verified with FEA results. The proposed design is also compared with its classical counterpart 8/6 SRM on the basis of torque output and torque per ampere ratio which are obtained from Static FEA simulation. The results indicated 8/22 SRM has a better torque performance and higher torque per ampere ratio in comparison to 8/6 SRM due to the increased variation of co-energy of the field with respect to rotor position at a constant current. This makes 8/22 SRM a promising candidate for high torque density applications in EVs and industrial applications.