Design And Temperature Field Calculation Of High Efficiency Permanent Magnet Drive Motor For Commercial Vehicles

In this paper,an 80kW interior permanent magnet synchronous motor(IPMSM)is used as an example to study the electromagnetic design,topology optimization and temperature field analysis of the permanent magnet drive motor used for electric vehicles(EVs).And the main work is as follows:Firstly,the design target of the permanent magnet drive motor is analyzed.Based on the design theory of permanent magnet motor and starting from the design of the motor's d,q axis magnetic circuit,the factors affecting the overload capacity and speed range of permanent magnet motor are studied and the overall size of the IPMSM is calculated.Subsequently,the 2D finite element simulation model of the IPMSM is built by using Maxwell software and the performance of motor in no-load and load conditions is calculated.Secondly,the structure of the stator and rotor topology are optimized that the influence of d,q axis inductances,saliency ratio and field-weakening magnetic rate on the motor performances under different magnetic structures are calculated and compared by building the 2D finite element method(FEM)model.The changes of motor reluctance torque,overload capacity and weak magnetic capacity when choosing different tooth-slot ratio and tooth-yoke ratio are analyzed and calculated.And the influence of angle between the permanent magnet,permanent magnet usage and magnetic bridge size on the peak torque of motor and the utilization of permanent magnet are analyzed.Then the optimal motor topology is obtained and the performance of IPMSM is compared with the pre-optimized one.Then,based on basic theory of heat transfer and combining the motor losses value calculated by FEM,the thermal network simulation model of the IPMSM is established to calculate the temperature rise of each part in the rated steady state condition and peak transient condition.In addition,in order to verify the anti-demagnetizing ability of permanent magnet and the mechanical strength of the rotor,the maximum demagnetization current and force and deformation of the rotor are simulated.Finally,the prototype is manufactured and the experimental platform is set up.The performance and temperature rise of the motor under different working conditions are tested.Meanwhile,the experimental results are compared with the simulation results which proved the accuracy and feasibility of FEM.All the results show that V-shape IPMSM has the advantages of high overload capacity and wide speed range which has potential to apply in the EVs applications.