Research On Drive Control System Of PMSM For Vehicles

Traditional fuel vehicles consume a large amount of fossil energy,automobile exhaust emissions polluting the urban environment.In contrast,the new energy electric vehicle is pollution-free.Therefore,the important international automobile manufacturers take electric vehicles as an important direction of future development of the car.And the largest development bottleneck of electric vehicles in the world is endurance mileage.The minimum switching loss SVPWM is adopted to reduce the switching loss of the inverter and save the energy of the vehicle accordingly.And the modulation method is applied to the MTPA control and weak magnetic control of permanent magnet synchronous motor.At the same time,the model predictive control is applied to improve the torque disturbance rejection and torque following performance of the electric vehicle in dynamic condition.The built-in PMSM as the research object,we establish the mathematical model of the motor in the rotating coordinate system firstly.According to the different decomposition combination of stator current,we form the control of id=0 and MTPA control and weak magnetic control.Secondly,we put forward the improvement of five segments SVPWM to solve the problems of large switching losses of the conventional seven segments SVPWM,and conventional five segments SVPWM under the same bridge arm which switch is not the same.In order to solve the problem of five segment SVPWM output current harmonics,the optimization method is based on the improved five stage SVPWM method,and the minimum switching loss SVPWM mode is obtained.The method can further reduce the switching loss of the inverter,and limiting the voltage and current harmonic output.The minimum switching loss SVPWM mode simulation model is set up,and the optimized modulation mode is verified in vector control,and the simulation results are analyzed.The optimized SVPWM mode is expanded to the full speed range of motor control strategy,adopting MTPA control under base speed and adopting weak magnetic control on base speed.Building MTPA and weak magnetic control simulation model based on optimized SVPWM in the matlab/simulink respectively,the simulation results of the two control methods are analyzed.In addition,in order to further improving the torque and speed following performance and torque disturbance rejection performance of the electric vehicle under dynamic conditions,the model predictive control is applied to the speed loop controller,and the speed loop model predictive controller is set up,and the model predictive controller and PI controller in the vector control mode are compared and analyzed.Finally,the hardware platform with TMS320F28335 as the control core is established,the main circuit,control circuit,detection circuit and protection circuit are designed.On this platform,the software design of vector control mode is carried out,and the programming of each module of the software is completed.In the platform completing the relevant experiments,verifying the design of the drive control system is reasonable.