Optimal Design Of Switched Reluctance Motor Based On Finite Element Method

The significant defect of switched reluctance motor(SRM)is that the torque ripple is too large, this has become the main barrier to the application and development of the motor. For a long time, many experts and scholars are committed to research how to reduce the torque ripple, most of which are control optimization. In this paper, based on the optimization of the motor body, based on the traditional SRM, the improved stator and rotor structure is combined with the high performance permanent magnet material to form a new type of hybrid excitation SRM structure to improve the performance of the motor.First of all, the basic equations of the switched reluctance motor and three kinds of mathematical models are analyzed in detail, and the reasons of the formation of the torque ripple are discussed.Secondly, the finite element software ANSOFT is used to establish the two-dimensional simulation model, and the static flux, inductance, magnetic co energy, torque, air gap magnetic density and mechanical transient characteristics are analyzed; The influence of the air gap, the stator and rotor yoke thickness and the pole arc on the static characteristic and the pulsation is discussed, and the corresponding rules are obtained; Based on the basis of the above analysis, this paper puts forward a method of rotor yoke open holes, the stator pole with improved motor structure of the wedge angle of and to analyze the influence of hole size and the wedge angle on the performance of the motor, simulation, we compare the improved after motor torque characteristics and verify the structure can effectively reduce the torque ripple.At the same time, in order to increase the average torque of the motor, a hybrid excitation motor is proposed, which is embedded in the stator pole. The difference of the working principle of the permanent magnet is analyzed; Based on the magnetic circuit method, the influence of permanent magnet reluctance torque characteristics, permanent magnet, winding current and structure parameters on its effect is analyzed, and the corresponding rules are summarized; Compared with the improved SRM performance, the average torque of the motor is improved.Finally, the basic principles and operations of genetic algorithm are introduced briefly; The optimization module and the use method of Maxwell 2D are described in detail, and the genetic algorithm is used to optimize the design of hybrid excitation SRM, and the approximate optimal solution is obtained, the optimization results show that the torque ripple can be effectively suppressed, and the performance of the motor is improved, which provides a new idea for the optimal design of the motor.