Design And Analysis Of Novel Surface Inset Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor has the advantages of simple structure,high power density and high efficiency,which has attracted widespread attentions in the military and civilian fields.According to the position of the permanent magnet on the rotor,the permanent magnet synchronous motor is mainly classified as the surface mounted permanent magnet synchronous motor,surface inset permanent magnet synchronous motor,and interior permanent magnet synchronous motor.Among them,the surface inset permanent magnet synchronous motor has a simple structure,and it can make use of two torque components of the magnetic torque and reluctance torque,contributing to obtain not only high torque density and efficiency,but also wide field weakening speed regulation range,exhibiting the broad application prospects.However,although the traditional surface inset permanent magnet synchronous motor produces magnetic torque and reluctance torque,it was found in the research that the two torque components cannot be fully utilized,which limits the improvement of electromagnetic torque.Therefore,on the basis of fully analyzing the structural characteristics and torque characteristics of the traditional surface inset permanent magnet synchronous motor,the novel surface inset permanent magnet synchronous motor with an asymmetric rotor structure is proposed in this thesis.The design of the configuration angle between the rotor salient pole and permanent magnet can reduce the superimposed difference of the current phase angles of the maximum values of the magnetic torque and reluctance torque,thereby improving the utilization of the torque components and electromagnetic torque,thus improving the motor electromagnetic performance.In order to highlight the advantages of the novel surface inset permanent magnet synchronous motor,this thesis adopts the comparative research method.Based on the design of the traditional surface inset permanent magnet synchronous motor,the novel surface inset permanent magnet synchronous motor is designed and optimized,and then the motor performance are compared.The detailed research work is as follows:First,the structural characteristics and working principles of the traditional and novel surface inset permanent magnet synchronous motors are introduced.Based on the size design of traditional surface inset permanent magnet synchronous motors,the basic electromagnetic parameters of the novel surface inset permanent magnet synchronous motors are determined.The electromagnetic performance and vibration and noise performance under different pole slot combinations are obtained,and the basic model for further optimization analysis of the novel surface inset permanent magnet synchronous motor is obtained.Then,based on the size,material,and main specifications of the basic model,the multiple parameters of the basic model are optimized with the optimization goal of maximizing average torque and minimizing torque ripple,thus to obtain the proposed model:(1)With the aid of the Latin hypercube sampling algorithm,the sensitivity analysis of variable parameters that affect the average torque and torque ripple are carried out by fixing the amount of permanent magnets as the constraint.The parameters include stator tooth top,stator tooth width,stator slot opening width,salient pole width angle,salient pole length,and the angle between salient pole and permanent magnet.The high-sensitivity parameters and low-sensitivity parameters are then determined,and the weight ratio of each optimized parameter is also determined.(2)The Kriging approximation model is established based on high-sensitivity parameters,and the genetic algorithms are utilized to obtain the optimal rotor structure of the proposed model.Through the finite element method,the performance of the proposed model and the basic model are analyzed and compared.The results show that the maximum values of the magnetic torque and reluctance torque of the proposed model meet at the nearby current phase angles,which is reduced from the original 45 degrees superimposed difference to 16.5 degrees.The utilization of torque components is highly improved,and the average torque is improved by 25%,and torque ripple decreased by 3.9%.Finally,the vibration and noise analysis of the motor are carried out based on the analysis of magnetomotive force,the stator and rotor slotting effect on the air gap magnetic permeability,the air gap magnetic density and electromagnetic force wave.And the modal and harmonic response vibration analysis are also carried out.The analysis results verify the vibration and noise performance of the novel surface inset permanent magnet synchronous motor.