| Permanent magnet synchronous motor(PMSM)has many advantages such as small size,high magnet energy density,large starting torque,and is widely used in the field of electric vehicles.This paper studied the PMSM control algorithm,and select suitable control strategy to use in electric vehicle,and optimized it to improve the running performance of electric vehicle.Established a permanent magnet synchronous motor control model by studying permanent magnet synchronous motor mathematical model and voltage Space Vector Pulse Width Modulation(SVPWM)technology,and it used to be the base of control algorithm.For the permanent magnet synchronous motor position sensor installation cost is high,easily to be affected by the harsh working environment,studied sensorless control algorithm to replace the position sensor.At medium and high speeds,used a Sliding Mode Observer(SMO)method and Model Reference Adaptive System(MRAS)to estimate rotor position.The former estimates the rotor position and speed by observing the back-EMF value.while the latter does not need to observe back-EMF,It used adjustable model and the reference model,designed adaptive law based on the Popov hyper-stability theory to estimate the rotor position and speed.At zero-low speed,the rotor position estimation is performed by using the pulse high-frequency voltage signal injection method to extract and process the response of the injection of the high-frequency signal in the motor.The simulation results show that using the above methods,the motor can be controlled without sensors.For the demand of electric vehicle power performance,the optimization of the Maximum-Torque-Per-Ampere(MTPA)control algorithm was studied,analyzed the influence of MTPA control of formula method when motor parameters was changed,proposed an optimized table look-up method for MTPA control.The target current was used as the input variable for table lookup and redesigned the MTPA control function.After optimization,the control was not affected by the changes of motor parameters,it can output the maximum torque at a given current below the rated speed.Designed a motor test system based on LabVIEW for motor and drive tested.Used MATLAB/Simulink to simulate and verify the proposed control strategy.Based on the TMS32F28069 control chip,used Code Composer Studio development platform to design the control algorithm software.The experiments proved that the optimized table look-up method can achieve the maximum torque output for a given current below the rated speed. |
