| As global vehicle ownership escalates,the consequent energy consumption and environmental pollution are becoming increasingly pressing concerns.In this context,electric vehicles(EVs),as a novel form of energy-efficient transportation,are garnering significant interest from automotive research institutes and developers worldwide due to their potential for reducing energy consumption and emissions.Presently,the range of EVs constitutes a critical factor for evaluating their performance;however,the range performance remains suboptimal,primarily due to limitations in key technologies such as battery systems.To address the issue of EV range,regenerative braking energy recovery technology has been proposed.This technology serves as an essential means of environmental protection and energy conservation for EVs,providing not only a specific amount of regenerative braking torque during the braking process but also enhancing the vehicles’ range.Consequently,to maximize the energy recovery of regenerative braking systems while ensuring EV safety performance,it is necessary to devise a rational and effective braking force distribution strategy.The primary research work presented in this paper encompasses the following aspects:(1)A comprehensive examination of domestic and international research and applications of regenerative braking energy recovery for EVs is conducted,with detailed analyses of the advantages and disadvantages of various braking energy recovery control strategies.By scrutinizing the mechanics of the braking process in pure electric front-drive models,the study establishes an appropriate braking force curve.Employing Matlab software,this investigation lays a theoretical groundwork for optimizing the boundary conditions of the multi-objective optimization algorithm.(2)Based on Simulink software,a forward simulation modeling method for key components of pure electric vehicles is introduced.Three permanent magnet synchronous motor and Rint battery models are selected for simulating ECE cycle conditions under a fixed-ratio regenerative braking control strategy.Through a thorough analysis of simulation results,the variations of battery SOC(state of charge),motor power,and motor torque under different operating conditions are discussed in detail,providing valuable insights for the performance optimization and control strategy research of pure electric vehicles.(3)A summary of several existing multi-objective optimization algorithms is provided,and an enhanced multi-objective optimization strategy is proposed,aiming to guarantee braking safety while maximizing regenerative braking energy recovery.Following 200 iterations,three-dimensional graphs pertaining to braking intensity are generated.By incorporating these charts into the regenerative braking control strategy,simulation experiments are performed in conjunction with a pure electric vehicle model under ECE cycle operating conditions.Key indicators,such as the vehicle’s SOC under these conditions,are analyzed to assess the impact of the optimized regenerative braking control strategy on the performance of the pure electric vehicle.(4)The efficacy of the motor control strategy is corroborated by constructing a hardware-in-the-loop experimental platform for permanent magnet synchronous motors.Experimental results demonstrate that the regenerative braking force distribution method proposed in this paper exhibits excellent performance and robustness.Under identical vehicle speed and braking distance conditions,the proposed method enhances the energy recovery rate by 5%～10% compared to conventional braking force distribution methods.Simultaneously,the proposed method ensures the stability and safety of the braking system,taking into account the uncertainty of road surface adhesion coefficients.Therefore,this method holds promise for promotion and practical application in new energy vehicle braking systems. |
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