Research On Control Strategy For Pure Electric Vehicle

The vehicle control unit is the upper layer decision control unit of the electric vehicle.It is responsible for coordinating the work of the components such as driving motor,power battery and accessories.It has the advantages of improving the dynamic performance,safety performance and economic performance of the vehicle and so on.In this paper,the pure electric bus vehicle controller was studied,the main contents are as follows:(1)Analyzed the current situation of vehicle controller research at home and abroad,and tracked the research trend of vehicle controller.This paper analyzes the structure of the pure electric bus control system and the layout of the power system,introduces the functions of the vehicle controller,The working characteristics and common fault types of the motor system and power battery pack system are analyzed,which provide the basis for the research of vehicle controller control strategy.(2)The MATLAB / Simulink simulation model of pure electric bus is established,which includes the driver model,the motor and the controller model,the battery model,the transmission system model,the vehicle dynamics model and so on,combined with the vehicle related technical parameters analyzed the driving range,energy consumption,voltage,current and other parameters.Based on the accelerator pedal opening degree and its rate of change combined with the neural network algorithm,the driver's intention is analyzed.The simulation results show that the actual output torque of the motor is in accordance with the driving intention,the vehicle handling stability is good.(3)Based on the electrical schematic diagram of the VCU,the electrical structure of the vehicle control is analyzed.Combined with the function of the controller,the software design of the vehicle controller is determined according to the V-shaped development mode.Based on Infineon 32-bit high-performance microprocessors,completed the VCU bottom code and control strategy code development.The control strategy mainly includes driving torque control strategy,braking energy recovery control strategy,vehicle safety control strategy,fault diagnosis and processing control strategy.(4)Based on the Canadian D & V platform,built a VCU bench test system,developed the host computer control software using VB development environment.The test results show that the developed VCU can respond well to the driver's intention,the motor output torque is smooth,there is no impact.(5)The static test and the actual road test of the VCU are carried out to verify the effectiveness and reliability of the driving torque control strategy and the braking energy recovery strategy,and the control strategy is optimized to increase the vehicle's driving range.