| As a clean energy vehicle,electric vehicle has become the important direction of the development of new energy vehicles in the world because of its high energy efficiency,low noise and zero emissions.Permanent magnet synchronous motor(PMSM)has attracted wide attention in the motor industry because of its simple structure,high efficiency,high power density and excellent speed control performance.It has also been widely used in the field of electric vehicles.Based on the application of finite element analysis and field-circuit combination design method,this paper analyzes the design and operation characteristics of permanent magnet synchronous hub motor for electric vehicles,analyzes the influence of magnetic circuit structure parameters on the performance of the motor,and develops a high efficiency,high power density,high overload multiple drive electricity suitable for electric vehicles.The design method of permanent magnet synchronous motor for electric vehicle is summarized,which lays the foundation for the later development of series products.The main research work of this paper is as follows:According to the key technology of the development of electric vehicles and combing with the special operating conditions and driving characteristics of electric vehicles,this paper chooses interior permanent magnet synchronous motor as the research object.And through the analysis of its structure characteristics and working principle,this paper determines the design task objectives in order to making motor suitable for the electric vehicles.Based on the finite element software and electromechanics and related electromagnetic field theory,this paper uses the field-circuit design method to determine the design scheme of the motor.In this paper,the preliminary design of the prototype is completed,including the main size design of the motor,winding scheme determination,pole-slot matching selection,permanent magnet parameter calculation,permanent magnet magnetization direction analysis,air gap length design and so on.Then according to the electromagnetic design scheme of the motor,the finite element solution model is established,and the finite element analysis and calculation of the motor are carried out,including the simulation of no-load,load and overload conditions.And based on the simulation,magnetic field distribution,air gap magnetic density,no-load back EMF,cogging torque,torque speed and permanent magnet eddy current loss are analyzed.This paper also studies the influence of the structure parameters of the motor on the motor,and analyzes the performance of the motor from the rotor structure.In order to ensure that the designed motor structure can meet the actual operating conditions of the mechanical strength requirements,this paper also carries out the mechanical structure simulation of the motor to ensure that the stress of the various parts of the motor can meet the yield strength requirements of the materials to ensure the stable operation of the motor.Finally,a prototype with rated power of 8.5 kW and rated speed of 650 r/min is made.The performance of the prototype is tested.The test results show that the prototype has a large overload multiple and high efficiency operation area,and achieves the expected design goals. |
