Research On Thermal Performance Under Multi-operating Conditions And Cooling Water-jacket Of Water-cooled Permanent Magnet Synchronous Motor

With the national emphasis on electric vehicles and increased investment in scientific research,Pure electric vehicle industry breaks through one and another technical bottlenecks and develops rapidly.The permanent magnet synchronous motor as the core component of an electric vehicle combines the advantages of high efficiency and power density.However,due to the limitations of vehicle space and the pursuit of motor power,it is always desired to design permanent magnet synchronous motors with higher power density.The higher the power density of the motor,the more serious the heating problem becomes.Excessive temperature rise is a threat to the performance and life of the motor.Therefore,it is urgent to study and solve the problem of temperature rise and heating of the permanent magnet synchronous motor.This thesis first introduces the background of the development of electric vehicles under the demand of energy saving and emission reduction,then,the article talks about the research progress of domestic and foreign scholars on the temperature rise and motor temperature field analysis of permanent magnet synchronous motors.Second,in order to accurately calculate the loss of each part of the permanent magnet synchronous motor.The article start with the theoretical calculation formula for various losses.Using Maxwell electromagnetic field simulation software.The stator and rotor iron losses,winding copper losses and permanent magnet eddy current losses of 80 kW permanent magnet synchronous motor were calculated by transient field analysis.Then,a thermal network model of permanent magnet synchronous motor was established by the Motor-CAD software.After that,the thermal field distribution of permanent magnet synchronous motor was calculated under multi-operating conditions.Comparing the calculation results with experimental data.Then,using UG(UnigraphicsNX)software,a 1:1 three-dimensional solid model of permanent magnet synchronous motor was established.Three-dimensional finite element method is used to calculate the temperature field of the motor.In the simulation calculation,the loss values of various parts of the motor are converted into heat flux values,the boundary conditions of each part are given,the temperature field distribution of the motor is calculated using Fluent software,and the calculation results are compared with the experimental data.Finally,in order to further investigate the rationality of the design of the permanent magnet synchronous motor structure and cooling method,the temperature field distribution is calculated by fluent when the motor adopts two different shapes of cooling water channels.For the spiral waterway,the distribution of the temperature field of the motor was calculated under different water injection methods.The shape of the spiralwater channel is used when different water injection methods are adopted.The temperature rise is calculated.Then,the effect of coolant injection speed on the temperature rise of the motor was studied.The optimal coolant injection speed of the motor was found.In short,this thesis through the study of permanent magnet synchronous motor's thermal characteristics under multi-operating conditions and cooling channels,the conclusions can be used to guide the design and production of similar motors and has a good engineering application value.