Research On Drive Control Performance And Parameter Identification Of PMSM For Electric Vehicle

As the core component of the new energy vehicle power system,the choice of drive motor is essential to ensure the power performance and energy saving effect of the vehicle.Interior permanent magnet synchronous motors(IPMSM)are widely used in electric vehicles due to their advantages in cost and performance.However,the output performance of the drive system is not only related to the motor body,but also affected by the control effect of the motor controller.The control effect of the motor has a strong dependence on the parameters of the motor,so the research on motor control and parameter identification also received attention.This paper takes a certain IPMSM applied to electric vehicles as the research object.The main research contents and work are as follows:Firstly,the relevant literatures are reviewed for the subject content,and the research status of vector control and parameter identification of the permanent magnet synchronous motor and drive motor for electric vehicles is summarized.After introducing the internal structure and working principle of IPMSM,the mathematical model of the IPMSM in the d-q axis system with neglected loss is established.On this basis,for the principle that the driving IPMSM corresponds to different control strategies in different operating regions,the maximum torque per ampere(MTPA)control of the motor in the low-speed and high torque region and the weakening control of the high-speed operation phase are determined,and the corresponding current constraints been studied.Secondly,from the perspective of the output characteristics of the driving motor under different control strategies,the influence mechanism of the motor parameters on the control performance of MTPA control and weakening control is theoretically analyzed.It is mainly reflected in the analysis of the direct and cross-axis inductance Ld,Lq and the rotor permanent magnet flux linkage have effect on the parameters that can reflect the output characteristics of drive motor,such as the output power factor of the motor,the turning speed of the MTPA control,the maximum speed that the motor can reach,and the output power corresponding to different speeds.The vector control system of the drive motor is built in the MATLAB/Simulink environment,and the conclusions obtained by the analysis are verified by simulation.Then,the motor parameters that have a significant influence on the control performance of the driving IPMSM proposed in this paper,that is,the direct and cross-axis inductances Ld,Lq and the permanent magnet flux Ψf are identified offline and online.Using the model reference adaptive method based on Popov hyper stability,the adaptive rate of the parameter identification system is obtained by inversely solving the Popov inequality,and the corresponding simulation model is built.Simulation results show the correctness of the model and method.Finally,a test platform for the drive motor was built,and the bench test of the drive motor and the off-line measurement calculation of the parameters were carried out.Finally,a test platform for the drive motor was built,and the bench test of the drive motor and the off-line measurement calculation of the parameters were carried out,By comparing the parameter calculation results and the difference between theoretical and practical characteristics,verify the results of the previous analysis.According to the parameter identification result obtained in the previous section,the actual torque-speed characteristic is more consistent with the given torque speed characteristic by adjusting the relevant parameter values in the controller control algorithm.