Research On Direct Torque Control Of Regenerative Braking For Permanent Magnet Synchronous Motor

With the emergence of global resource crisis and environmental protection pressure,electric vehicles quickly attracted people's attention with high energy efficiency,environmental pollution and other advantages and have a rapid development.Electric vehicles have been considered one of the important means of transport in the future.However,the electric vehicle driving problem maily limits its commercialization.Brake energy feedback technology can effectively extend the electric vehicle driving range and has a positive meaning to the energy-saving emission reduction.This paper mainly studies the direct torque control of regenerative braking of the permanent magnet synchronous motor,and has certain theoretical and practical significance for the development of electric vehicle.The article inferring the mathematical model of the permanent magnet synchronous motor in three commonly involved coordinates based on the principle of space vector.On this basis,analyzing the direct torque control principle of permanent magnet synchronous motor in detail.In the MATLAB/Simulink,the direct torque control model of permanent magnet synchronous motor is established.Then,the fuzzy controller is designed with the battery SOC,the vehicle speed and the braking strength as the input and the regenerative braking ratio as the output.Based on the automobile braking mechanics,the electro-hydraulic compound braking force distribution model of the electric vehicle is established in the MATLAB/Simulink.At the same time,the direct torque control model of the regenerative brake of the permanent magnet synchronous motor under the ECE driving condition of the electric vehicle is established by combining the direct torque control model of the permanent magnet synchronous motor.The simulation shows that the direct torque control can reproduce the motor.The braking torque is well controlled,which provides the theoretical basis for the development and experiment of the follow-up motor test bench.Finally,the direct torque control experiment of regenerative braking of motor is completed.Compared with the simulation results,the experimental bench can realize the control of regenerative braking torque and satisfy the regenerative braking torque of permanent magnet synchronous motor and the required functional requirements for the control.And it can provide a method for further application of the electro-hydraulic compound regenerative braking vehicle.