Comparative Study On Torque Distribution Strategy Of Distributed Driven Electric Vehicle Driven By Hub Motor

Environmental pollution and energy shortage are problems the modern industry facing.And the development of new energy vehicles is one of the effective measures to solve these problems.In electric vehicles,distributed driven pure electric vehicles have unique advantages in energy efficiency,maneuverability,comfort and economy,and have broad space for development.In the research of distributed drive electric vehicle,each wheel is equipped with an independent driving motor,however how to coordinate the power balance between all motors is an urgent problem to solve.In view of the above situation,taking distributed drive electric vehicle as the main object of study,this dissertation makes in-depth analysis and research from vehicle driving system modeling,system main parts selection and modeling,torque allocation strategy design,and electric drive energy efficiency.In the aspect of configuration analysis of distributed drive electric vehicle,its working mode is discussed.According to its energy flow analysis results,the working mode of main components of vehicle power system is determined.From the point of view of technical characteristics and energy efficiency enhancement potential,the distributed drive electric vehicle and other types of new energy vehicles are compared and analyzed.In terms of modeling and research of main components of power system,combined with MAP diagram and dynamic working process of each component,a mathematical model of main components including drive motor,power battery and inverter is established,and a simulation platform is built for control strategy optimization and comparative analysis.In terms of the research of distributed drive torque allocation optimization strategy,the torque allocation optimization strategy based on dynamic programming algorithm and fuzzy control algorithm is realized respectively.In the control strategy of torque allocation based on dynamic programming algorithm,taking the energy efficiency of power system as an optimization objective and combining with the boundary conditions of components,the global optimization is carried out under the condition of China urban road and NEDC.In the control strategy of torque allocation based on fuzzy control algorithm,fuzzy membership function and fuzzy rule are formulated according to torque demand,and energy efficiency is calculated under NEDC working conditions.The two control strategies are compared with the torque average allocation control strategy to compare the energy efficiency.The results show that the proposed DP optimization and fuzzy rule based torque allocation control strategy can effectively improve the energy efficiency of the power system and increase the pure electric driving mileage compared with the torque average allocation control strategy.