Study On Control Strategy Of Dual-motor Driving System For Pure Electric Bus

With people’s increasing attention to environmental pollution,pure electric bus is getting more and more attention.Thanks to its advantages of zero pollution,zero emission and low cost,pure electric bus has gradually replaced the traditional internal combustion engine bus.At present,most of the pure electric buses are driven by single motor matching single-stage reducer.Although the single-motor driving system is simple in structure and convenient in control,there are still some problems such as low motor load rate,insufficient power performance and short driving range.In order to solve the above-mentioned problems of single-motor driving,this paper studies the transformation of pure electric bus from single-motor driving to dual-motor driving.The research content and results are detailed below.(1)The typical double-motor driving system configurations are compared and analyzed.Combined with the structural characteristics,working principles,advantages and disadvantages of different double-motor configurations,a double motor configuration which is suitable for the demand of pure electric bus in this paper is selected.(2)Taking a certain 8m pure electric bus as the research object and satisfying the dynamic performance indexes of the original bus as the constraint condition,parameter matching method based on vehicle dynamic performance index and cycle condition is adopted to carry out the preliminary matching calculation of the parameters of the double-motor configuration selected.(3)Based on MATLAB/SIMULINK,the drive control strategy suitable for the doublemotor coupling driving system selected is designed.This paper mainly studies the calculation of required torque,the division of driving modes and the torque distribution.According to the division strategy of driving mode,the principle of minimum electric power required by the motor is adopted for division is formulated.For the torque distribution strategy,the instantaneous optimization algorithm based on the optimal motor efficiency is adopted to formulate the torque distribution mode.The joint simulation model based on MATLAB/SIMULINK and CRUISE is established,and the relevant dynamic and economic simulation is carried out.Compared with the traditional single-motor driving system,the rationality and validity of the proposed research content and method are verified.(4)With the vehicle dynamic requirements as constraints and 100 km power consumption as optimization objective,the simulated annealing particle swarm are used to optimize the primary transmission ratio parameters by PYTHON software.The optimized transmission ratio parameters are introduced into the whole vehicle simulation model for simulation.The results show that the energy saving potential of the vehicle is further improved on the premise of meeting the dynamic requirements.The research purpose of this paper is to verify the dynamic performance and energy saving potential advantages of the dual-motor configuration by formulating the vehicle driving control strategy and optimizing control parameters.The research in this paper is of great significance to improve the energy utilization rate of the whole vehicle and the dynamic performance and economy of the vehicle.