Finite Element Analysis And Optimization Design Of Permanent Magnet Synchronous Motor Of Electric Vehicle

With the rapid development of the world economy,cars have become an indispensable means of transportation for people to travel.However,the extensive use of traditional fuel vehicles has also brought certain environmental and energy problems.Therefore,vigorously developing energy-saving and environment-friendly new energy vehicles,especially electric vehicles,has become a major focus of the society.As the core component of electric vehicle,the performance of electric motor is directly related to the running state of electric vehicle.Permanent magnet synchronous motor(PMSM)has the characteristics of high efficiency,high power density,strong reliability and so on.It is very suitable for the performance requirements of low speed,high torque,wide and weak magnetic speed adjustment range of the driving motor for electric vehicles.In this thesis,the permanent magnet synchronous motor(PMSM)for electric vehicle is analyzed,designed and optimized based on finite element method and electromagnetic field theory.Based on the operation principle,steady-state performance and mathematical model of the permanent magnet synchronous motor,the electromagnetic design of the motor is carried out according to the engineering design experience and relevant formulas,and the preliminary design scheme of the motor is obtained.Based on the rapidity of the magnetic circuit method,the rationality of the design scheme was verified,and the related performance of the motor was improved by parametric analysis.The electromagnetic performance of the permanent magnet synchronous motor is simulated by finite element method,and the magnetic density distribution,air gap magnetic density waveform and back electromotive force waveform of the permanent magnet synchronous motor under no-load are obtained.Genetic algorithm was used to optimize the cogging torque,air gap flux density and permanent magnet consumption of the motor.The load condition of the motor is analyzed,and the internal magnetic field distribution of the motor in the rated condition is calculated,as well as the performance curves of torque,stator current,induced electromotive force and loss,etc.The results show that the motor runs smoothly.At low speed,the motor can provide a large electromagnetic torque,with a strong overload capacity;At high speed,the motor can still provide the required power,with a wide speed range.Adopts parametric analysis,calculate the motor efficiency based on speed-torque,input voltage,input current and losses of the MAP figure,the results show that the motor can keep more than 95% on a wide range of high efficiency,strong life,and sums up the torque and the input voltage,speed and the relationship between the input current,finally,the loss of the motor under different cases are analyzed.