Design Of High Power Density Motor Drive System For Electric Vehicle

With the rapid development of electric vehicles,how to improve the power density of the drive motor in the electric drive system is the main research direction of the current electric vehicle industry.Compared with other motors,permanent magnet synchronous motor has more advantages in volume,weight,loss and efficiency.In order to further improve the power density of permanent magnet synchronous motor in electric vehicle drive system,amorphous alloy and silicon steel are laminated together as stator,aiming at designing a high power density permanent magnet synchronous motor for electric vehicle drive system.First of all,after the mechanical analysis of the electric vehicle and the parameter design of the drive system,the technical indicators of the hybrid stator permanent magnet synchronous motor are proposed.In this paper,after dynamic analysis of electric vehicle and parameter design of driving system,the technical index of permanent magnet synchronous motor in driving system of electric vehicle is preliminarily determined.In order to solve the problem of low saturation magnetic induction of amorphous alloy,a new amorphous alloy with high saturation magnetic induction and low coercivity was designed with the help of machine learning and the first principles software.With regard to electromagnetic structure design,the proportion of amorphous alloy in motor stator is preliminarily determined through efficiency improvement.Parametric design of stator slot width,slot depth and stator tooth width is carried out by using Motor-CAD.After the pole slot matching scheme,the main dimensions,stator winding and rotor structure of the motor are designed accordingly.A three-dimensional model of the motor is established by using Motor-CAD and Ansys EM,and the basic performance is simulated.On this basis,aiming at improving the power density of permanent magnet synchronous motor,the corresponding optimization design is carried out,and then the cogging torque of amorphous alloy permanent magnet synchronous motor is optimized accordingly.Finally,in order to meet the heat dissipation requirements of the high-power dense amorphous alloy permanent magnet synchronous motor in operation,the temperature field of the motor is analyzed by using the thermal network method after various losses of the motor are determined,and the corresponding casing water cooling system is designed according to the internal temperature distribution of the motor.The fluid field of four common waterways is analyzed by using fluid dynamics,and finally it is determined that the waterway structure of the casing water cooling system is a spiral waterway.In order to further improve the heat dissipation capacity of the casing water cooling system,the number of water channels and the inlet flow rate of coolant are optimized accordingly,and the optimized casing water cooling system meets the requirements of insulation class H in all operating conditions.The paper has 110 pictures,48 tables,and 88 references.