Research On Modeling And Control Algorithms Of Permanent Magnet Synchronous Motors For New Energy Vehicles

In new energy vehicles,the electric motor is the main power source of its drive system,which determines the main performance indicators such as safety and power of the new energy vehicle.Among them,the permanent magnet synchronous motor has the characteristics of simple structure,low vibration and noise,high power factor and large torque inertia,and has been widely used in new energy vehicles.Therefore,with permanent magnet synchronous motor as the research object,the modeling and control algorithm research are carried out.The main research contents are as follows:(1)In the traditional permanent magnet synchronous motor mathematical model,the influence of non-linear factors such as loss,iron core saturation and cross-coupling is ignored,which leads to a certain error in the verification of the motor control algorithm.Therefore,the finite element model of the permanent magnet synchronous motor is established by the finite element method,which restores the real parameter changes inside the motor.(2)Aiming at the complex nonlinear system of permanent magnet synchronous motor,an auto-disturbance rejection control strategy that does not depend on the characteristics of the mathematical model of the controlled object is adopted to design the permanent magnet synchronous motor speed controller.And in the nonlinear extended state observer of traditional active disturbance rejection control,a nonlinear function based on finite time convergence is introduced.A system simulation model was built in MATLAB/Simulink.The simulation results show that the extended state observer based on the new nonlinear function has improved the convergence speed and tracking error performance,the response speed of the speed control system is improved,and the anti-disturbance ability is enhanced.(3)According to the actual working condition requirements of permanent magnet synchronous motors for new energy vehicles,speed zone control is carried out,and the improved active disturbance rejection control and i_d=0 control strategy are adopted below the base speed.Above the base speed,a control strategy combining improved active disturbance rejection control and field weakening control is adopted.In order to verify the effectiveness of the proposed permanent magnet synchronous motor speed control strategy,combined with the permanent magnet synchronous motor finite element model,the permanent magnet synchronous motor low-speed,high-speed and high-low-speed switching control strategy simulation study was carried out in MATLAB/Simulink.The simulation results show that the proposed speed control strategy meets the accuracy and stability requirements of the system.(4)In order to further verify the effectiveness of the proposed PMSM speed control strategy,a model-in-the-loop simulation experiment platform and a hardware-in-the-loop simulation experiment platform with a real controller are constructed to verify the designed control strategy.And in order to facilitate the observation of experimental data,a PMSM hardware-in-the-loop host computer monitoring platform is designed.Experimental verification shows that the designed permanent magnet synchronous motor speed zone control strategy has good robustness and operational stability,and meets the performance requirements of new energy vehicles under various working conditions.