Research On Control Strategy Of Brake Energy Recovery For Electric Vehicle Driven By Multi-hub Motor

New energy vehicles have significant advantages in energy consumption,vehicle spatial layout,and transmission efficiency,but short range is a key issue hindering the development of new energy vehicles In response to the issues of poor energy recovery performance of traditional braking control strategies and the need for further improvement of braking energy recovery control strategies for multi hub motor driven electric vehicles,this article mainly studies the braking energy recovery control strategy for multi hub motor driven electric vehicles.The research content is as follows:(1)Modeling of multi-wheel hub motor-driven electric vehicle.According to the national road vehicle standards and power performance test methods,design the whole vehicle parameters(wheelbase,rolling resistance,windward area,etc.)and performance indexes(range,100km acceleration,hill climb)of the electric vehicle,use the whole vehicle parameters for power performance calculation,obtain the whole vehicle motor,battery and other related data,import the data into CRUISE for the construction of the whole vehicle motor,battery and reducer modules,complete the Finally,the simulation tasks of acceleration,hill climbing and range are set according to the performance indexes,and the power and economy of the vehicle are analyzed.The results show that the built multi-hub motor-driven electric vehicle meets the performance indexes set,which provides model support for the braking control strategy of this paper.SIMULINK to build the vehicle longitudinal dynamics model using the whole vehicle parameters to simplify the simulation process;(2)Design an improved braking energy recovery control strategy.To solve this problem,adaptive fuzzy PID control is introduced into the system,and the longitudinal dynamics model of the whole vehicle is used to verify the effect of adaptive fuzzy PID control;adaptive fuzzy PID control is combined with the improved braking control strategy,and the speed simulation results show that the improved adaptive fuzzy PID control can achieve closed-loop control of vehicle speed and the control strategy is effective.Finally,the fuzzy control combined with the basic braking control strategy(improved fuzzy control strategy)is built to facilitate the comparison of the energy recovery effect between different control strategies later on;(3)Joint simulation of multi-wheel hub motor-driven electric vehicle with improved adaptive fuzzy PID control strategy model.After completing the software environment configuration,the evaluation indexes for judging the energy recovery effect are formulated,including the braking energy recovery rate and the battery SOC contribution rate;the dll and dbf files generated by the control model in(2)are imported into the CRUISE vehicle model in(1),and the NEDC working condition,FTP72 working condition and Ja1015 working condition in the city road working condition are selected for simulation respectively,while the typical braking The simulation task under typical braking conditions is added to analyze the energy recovery effect of the improved adaptive fuzzy PID control strategy by comparing the simulation results.The analysis of the simulation results shows that the improved adaptive fuzzy PID control strategy has higher braking energy recovery rate and battery SOC contribution rate in the NEDC,FTP72 and Ja1015 operating conditions compared with the improved fuzzy control strategy;the highest braking energy recovery rate and battery SOC contribution rate are both greater than 30%,which are higher than the improved fuzzy control strategy by Under Ja1015 conditions,the improved adaptive fuzzy PID control strategy has better speed following effect.Under typical braking conditions,the braking performance and energy recovery rate of the improved adaptive fuzzy PID control strategy are better than those of the improved fuzzy control strategy,with a maximum improvement of 10.8%in braking performance and 27.2%in energy recovery rate.The above results prove that the improved adaptive fuzzy PID control strategy can realize the closed-loop control of vehicle speed and better achieve the braking energy recovery.