Optimal Design Of Permanent Magnet Synchronous Motor For Electric Vehicle

With the increasingly prominent contradiction between energy,environment and vehicle ownership in the world,the competition of automobile industry in various countries has shifted from internal combustion engine vehicles to new energy vehicles.As the core component of new energy vehicles,motor manufacturers tend to choose permanent magnet synchronous motor with high power density.This paper takes the permanent magnet synchronous motor of a 4080 electric vehicle as the research object,carries out the static and modal analysis of its main components,establishes the electromagnetic field model of the motor,carries out the electromagnetic analysis and magneto thermal coupling analysis,and uses genetic algorithm to optimize the design of the motor.This study is of great significance to improve the efficiency of the motor,ensure the safety of the motor,and improve the efficiency of the early design of the motor designers.Firstly,the static and dynamic characteristics of the stator system,rotor system and casing are analyzed,and the variation laws of the stress,deformation,natural frequency and natural mode shape of the main components of the permanent magnet synchronous motor are obtained.Through the analysis of these data,the safety of the motor structure is judged,and the possibility of resonance between the main parts of the motor is analyzed.Secondly,the electromagnetic simulation model of the motor is established according to the structural parameters of the motor.The electromagnetic field of the motor is simulated under no-load and rated load,and the electromagnetic loss of the motor is obtained.The accuracy of the motor model is verified by the parameters of the motor;The accuracy of iron loss calculation is verified by comparing the data of magnetic field circuit calculation and field calculation;The accuracy of copper loss is verified by comparing the copper loss data calculated by finite element method and formula.The eddy current loss of permanent magnet is calculated by finite element method,and the influence of eddy current loss on motor temperature rise is analyzed.Then,the magneto thermal coupling simulation of electromagnetic field and fluid temperature field is carried out.The three-dimensional model of the temperature field of the motor is established by the three-dimensional modeling software.The electromagnetic loss calculated by the electromagnetic field analysis is coupled to the corresponding position of the three-dimensional model of the motor as a heat source,and the overall temperature distribution of the model is obtained.Finally,genetic algorithm is used to optimize the efficiency of the motor.Using response surface analysis,the functional relationship is constructed.Taking the width,thickness,rotor outer diameter and stator inner diameter of the permanent magnet as the optimization parameters,the range of the optimization parameters is set,and the magnetic density of the motor is taken as the constraint condition.Finally,the optimized parameters are substituted into the electromagnetic simulation model to verify the efficiency of the motor.