Parameter Matching And Mode Switching Control Of A Novel Dual Motors Coupled Electric Driving System

People’s life is becoming increasingly rich,the consumption level is constantly improving,and the car has also become a necessity from the luxury,which become an irreplaceable part of people’s daily life.With the increasing number of cars,the increase in energy consumption and pollution emissions has become an inevitable problem.In order to achieve energy conservation and emission reduction,various countries and car companies are developing towards the direction of new energy vehicles,and will apply more energy-saving technology to vehicles.With its own advantages,the electric vehicle is at the forefront of the development of automobiles.Compared with traditional fuel vehicles,electric vehicles can better combine with various technical means to improve performance to achieve the purpose of energy saving and emission reduction.In addition to increasing the battery capacity and optimizing the existing structure,there are also electric four-wheel driving technology,hub motor distributed driving technology,torque vectoring technology and dual motors coupled driving technology,which are important technical means to improve vehicle performance.In order to make full use of the advantages of coupled dual motors driving and maximum use of dual motors structure,on the premise of guaranteeing dynamic performance and improving the economic benefit of the vehicle,in this paper a novel dual motors coupled driving system is proposed.A variety of driving modes are available according to the need,aiming at maximizing the performance of the motor,for the future of electric vehicles to draw a heavy color.This paper firstly discusses the existing dual motors driving configurations and summarizes the shortcomings of the existing configurations.On the premise of making full use of the advantages of dual motors,a novel dual motors coupled driving system is proposed by combining it with the torque vectoring technology,which aims to further improve the economy on the premise of ensuring the dynamic performance.In view of the novel dual motors coupled driving system,three driving modes of the dual motors coupled are analyzed firstly,which are main motor driving alone,TV motor driving alone and dual motors torque coupled driving.The principle of energy saving is also briefly described.Then according to the dynamic requirements of a single motor parameters is matched,for the following economic comparison to make a cushion.On this basis,the parameters of the dual motors coupled driving system are matched.Due to the different functions of the two motors,the matching principle of the dynamic motor and the economic motor is put forward respectively,and the two motors also need to take into account the linear driving and torque vectoring requirements.After parameter matching,a seven-degree-of-freedom model of the vehicle and a novel dual motors coupled driving system model are built in Matlab /Simulink to verify the torque vectoring function.Then,the further verification is carried out by using the co-simulation of Car Sim and MATLAB/Simulink.In order to give full play to the energy saving potential of the dual motors coupled configuration,a mode switching control strategy is designed.The vehicle velocity following module,the demand torque solving module and the optimal driving mode judgment module are built.The velocity following module serves the velocity following during the subsequent simulation.The demand torque solving module provides the motion mode and economic mode according to the driver’s demand.The optimal driving mode judgment module traverses the equivalent external characteristics of the dual motors according to the required speed and required torque,and takes the one with the least required electric power among the three drive modes as the optimal driving mode.In addition,based on the logic threshold method,the region of the equivalent external characteristics map of the dual motors is divided to maximize the energy saving advantages.Finally,in order to verify the effectiveness of the novel dual motors coupled driving system and mode switching control strategy,based on AVL Cruise and MATLAB/Simulink cosimulation platform,a vehicle model with the novel dual motors coupled driving system built in Cruise will be co-simulated with the control strategy built in MATLAB/Simulink.Firstly,it is verified whether it can meet the dynamic performance index,and the results show that it can meet the dynamic demand.Then NEDC cycle condition and FTP-75 cycle condition are set respectively,and the single motor driving,dual motors torque equal-sharing driving and dual motors driving with mode switching control are compared.The results show that the energy consumption of the dual motors mode switching control strategy is the minimum in any working condition,and the energy saving potential of the dual motors is fully exerted.