Design And Research Of Parallel Hybrid Permanent Magnets Memory Motor For New Energy Vehicles

As people pay more and more attention to environmental issues,new energy vehicles will play an increasingly important role in the field of transportation.Drive motors provide power for new energy vehicles,and the research of drive motors for new energy vehicles is of great significance.Compared with the traditional permanent magnet motor,the memory motor has the advantage of adjusting magnetization state online,and the memory motor has the advantages of wide speed range and wide high efficiency zone,which is a strong competitor for electric drive system.This dissertation fully considers the actual drive cycle of the vehicle and the relevant constraints of permanent magnet motors for new energy vehicles,proposes a novel parallel hybrid permanent magnets memory motor,and determines the relevant performance parameters.The design methods of motor parameters are introduced,such as the main dimensions,the air gap length,and the stator winding.The parameters of the permanent magnets are determined by the method of experiment and simulation,and the principle of the cogging torque and the method of reducing the cogging torque are analyzed.The finite element models of the parallel hybrid permanent magnets memory motor and the series hybrid permanent magnets memory motor are established The equivalent magnetic circuit models and the principle of magnetization state adjustment of the hybrid permanent magnets memory motors are used to explain why the parallel hybrid permanent magnets memory motor has the larger magnetization state adjustment range.The performance of the proposed parallel hybrid permanent magnets memory motor and the series hybrid permanent magnets memory motor are compared by the finite element analysis,such as open circuit radial flux density,unintentional demagnetization with q-axis current,intentional demagnetization with d-axis current,torque capability,and efficiency characteristics.Torque ripple is one of the important factors affecting the smooth operation of the motor,based on the mechanism of torque ripple,this dissertation introduces a method of using auxiliary slots to reduce torque ripple.The number and parameters of rotor auxiliary slots are optimized based on particle swarm algorithm,and the optimal results are obtained.The dynamic voltage generated by the memory motor during the magnetization process will limit the adjustment range of the magnetization state.This dissertation analyzes the principle of dynamic voltage limit and proposes a "two-step" magnetization current strategy to alleviate the voltage limitation during the magnetization process.