Research On Pmsm Drive System And Thermal Management Technology For Electric Vehicles

The rapid growth of the internal combustion engine vehicles has brought great pressure to the environment.As a clean means of transportation,electric vehicles have attracted wide attention.With the development and use of electric vehicles,the driving motor and control technology has been greatly developed.In this paper,internal permanent magnet synchronous motor as the research object,the electric vehicle drive control system and thermal management technology are studied.In the light of the characteristics of high torque when starting and climbing at low speed and high speed when cruising and overtaking at high speed,the traditional MTPA control method based on formula method is improved at low speed stage,and the control method of high efficiency and low loss is explored.A virtual constant signal injection MTPA control strategy independent of motor parameters is proposed;In the high-speed stage,flux weakening control strategy is proposed to improve the torque utilization of the motor and meet the requirements of high-speed operation.The simulation software is used to build the control system model,and the waveform of the motor under different operating conditions is simulated,which provides a certain reference for the experiment.Aiming at the problem of high overload caused by poor working environment such as deep swamp in the system,considering the power safety of electric vehicles,the junction temperature estimation of IGBT power module in the control system is studied.The thermal network model method is used to estimate the junction temperature in real time.According to the junction temperature estimation results,the driving system is dynamically adjusted.The IGBT module and the three-dimensional solid model of the heat dissipation system are built,and the temperature field is simulated in the finite element analysis software ANSYS.At the same time,the accuracy of junction temperature estimation under different working conditions is verified with the help of Semisel tool.When the junction temperature of the power module exceeds the given threshold,the switching frequency of the control system is adjusted based on the linear relationship between the loss and the junction temperature.In the end,a system experimental platform is built,and the proposed control algorithm and junction temperature estimation scheme are applied to the actual system to evaluate the control performance under different working conditions and the accuracy of junction temperature estimation,and to verify the feasibility and effectiveness of the proposed drive control strategy and the thermal management strategy based on junction temperature estimation results.