Research On Braking Energy Recovery Of Hybrid Energy Storage Electric Vehicle

The protection of the environment by society has led to the rapid development of electric vehicles.The mileage of electric vehicles and the replacement cost of energy storage devices have always been a big problem.The motor of an electric vehicle participates in braking to recover the energy wasted in the braking process,and the use of supercapacitors as an auxiliary energy storage device for the battery is more conducive to extending the life of the battery.Therefore,the braking energy recovery of electric vehicles is of great significance to the development of electric vehicles.In this paper,supercapacitor auxiliary battery is used as a composite energy storage device,and the energy recovery of electric vehicles is studied using energy distribution strategies.First,by analyzing the working performance and characteristics of the battery,the lithium battery is selected as the battery for composite energy storage.Then,according to the charging and discharging characteristics of different energy storage devices,it is found that the double-layer super capacitor is more suitable as an auxiliary device for highpower input and output.The topology of the bidirectional DC-DC converter selects a bidirectional half bridge as the topology of the composite energy storage.Analyzed the constant speed driving state,starting state,braking state,etc.,formulated different working modes.Secondly,for the force analysis during the driving process of the electric vehicle,the appropriate front and rear axle braking force distribution method is formulated using the ECE regulation curve and the I curve.And use the car’s braking force strength,super capacitor SOC and battery SOC as input to develop a safe regenerative braking force friction ratio to ensure that more energy is recovered under safe working conditions.Then,according to the chemical characteristics of the battery,reduce the error in the simulation,calculate the voltage and internal resistance of different stages according to the current battery SOC state,and finally get the residual value of the battery SOC,build a battery module;according to the energy conversion efficiency of the super capacitor Determine the current SOC remaining value of the super capacitor and build a super capacitor module;Determine the terminal voltage change of the supercapacitor at a certain moment to ensure that the supercapacitor plays an auxiliary role to the battery.A two-way DC-DC module is built;through the power requirements of the electric vehicle driving conditions,the power bus module is built for the composite energy storage The system distributes energy.Finally,a secondary development was carried out on the ADVISOR2002 platform,and a composite energy storage electric vehicle simulation model was built.The braking energy recovery control strategy built in MATLAB/Simulink was imported into the vehicle model,and the composite energy storage The electric vehicle was simulated,and the results showed that the braking energy recovery of the composite energy storage electric vehicle improved the mileage and energy utilization rate;the battery in the composite energy storage was more stable and extended the battery life.Figure 52 table 5...