Research On Design And Heat Dissipation For High-Power Servo Motor

The permanent magnet motor has the advantages of small volume and high power density,but with the increase of power density,the heat dissipation area decreases,which leads to the increase of temperature rise.High temperature brought many adverse effects to the performance and reliability of the motor,so it is important to accurately calculate the motor loss and temperature field distribution within the various components,rational design the cooling system,and control the motor operating temperature in a safe range.The project is support by Liaoning province outstanding talented person project—the weak magnetism characteristic and the output ability research of the permanent magnet synchronous motor for electric vehicle.In this paper,a permanent magnet servo motor is studied to analyze the distribution of the fluid field and temperature field of the motor,and the important factors affecting the temperature field are studied.The work mainly from the following aspects:Firstly,based on computational fluid dynamics theory,the performance of axial-flow fan for motor cooling system is studied.The axial-flow fan fluid simulation model is established through three-dimensional modeling software,the rated speed is applied to the fan wall,and the flow field of the motor cooling system is simulated when the fan rotates.The fan performance is analyzed according to the fan velocity distribution and velocity vector distribution,and the average velocity of the fluid at the inlet is calculated.Secondly,analysis of fluid field and temperature field of motor based on heat transfer theory.The model of three-dimensional temperature field of the motor is established,the heat source parameters and material properties are determined,and the steady-state temperature field of the motor is calculated by using the fluid-solid coupled heat transfer method.By calculating the results,the fluid flow in the motor and the temperature distribution of each part are analyzed,the maximum temperature position of the motor is found and the temperature distribution of the motor is summarized.Then,the influence of different cooling structures and heat dissipation conditions on the temperature of the motor is analyzed.The simulation model of three cooling structures is established,the influence of cooling structure on the heat dissipation performance of the motor is calculated,and the optimum cooling structure is obtained.Comparing the temperature distribution of the motor in natural heat dissipation and forced air cooling,the variation trend of motor temperature under different flow velocity is studied.By setting up the experimental platform of temperature field,the temperature rise experiment of the prototype is carried out,the experimental data and the simulation data are compared to verify the correctness of the method adopted.Finally,a permanent magnet servo motor with rated power of 30 kW is designed.In the process of design,this paper calculates and analyzes the parameters such as pole-groove fit,rotor magnetic circuit,permanent magnet size and so on,and establishes the two-dimension calculation model of the motor by electromagnetic calculation software,and analyzes the static and dynamic performance of the motor.According to the motor design size manufacturing prototype,and testing the performance of the prototype,the experimental data show that the permanent magnet servo motor meets the design requirements.