Research And Optimization Of Hydraulic Regenerative Braking Energy Recovery System Based On Dual Accumulator

During the braking process of the automobile,there is a large amount of mechani cal energy turns into heat energy that's consumed.concerning this circumstance,the h ybrid vehicle with the braking energy recovery function has been developed.Pure elec tric vehicles have low cruising range and short battery life.In various hybrid vehicles,hydraulic hybrid vehicles have high power density and high energy recovery efficienc y,which is able to convert the mechanical energy which lost during braking process i nto the hydraulic potential energy which is stored in the accumulator efficiently.When the car starts or accelerates,releasing the energy stored in the accumulator provides all or part of the driving force for the car,which not only improves the fuel econom y of the car but also reduces environmental pollution.However,in our earlier study we found that the single accumulator hydraulic hybrid system is trapped in the choice of both braking characteristics and energy recovery efficiency.The dual accumulator can satisfy the braking characteristics of the vehicle and improve the braking energy r ecovery efficiency respectively.Aiming at the energy recovery efficiency of hydraulic regenerative braking and t he impact on automobile fuel economy,the hybrid hydraulic hybrid vehicle model of single/double accumulator is established respectively.The research content mainly inclu des the following aspects:(1)Contrasting and analyzing the characteristics in different structures of hydrauli c hybrid vehicles,and present the structural of the double accumulator parallel hydraul ic hybrid vehicle.The vehicle dynamics model is derived and the main components of the hydraulic hybrid system are derived mathematically.At the same time,the brakin g process of the car is analyzed,the braking characteristics are studied,the energy rec overy efficiency and brake safety are considered respectively,and the regenerative bra king force distribution strategy of the following vehicle simulation is determined.(2)The ADVISOR platform was redeveloped.In the traditional internal combustion vehicle model,the designed single/double accumulator module,hydraulic hybrid drive module,regenerative braking module and vehicle control strategy were added respecti vely.Through the simulation study of different cycle conditions,it is proved that the fuel economy of hydraulic hybrid vehicles is better,the fuel consumption of the 1015 drive cycle decreased by 6.3%,and the fuel consumption of the UDDS drive cycle de creased by 11.9%,the exhaust emissions are reduced.The cruising range of the hydra ulic hybrid vehicle with the double accumulator is further improved,and the pollution to the environment is further reduced.(3)In order to further improve the braking energy recovery efficiency of the hyd raulic hybrid vehicle and the fuel economy of the vehicle.A control strategy was desi gned based on the fuzzy theory with the accumulator SOC,the vehicle speed and the braking strength are input variables,and the regenerative braking force distribution co efficient is output.The control strategy further reducing the fuel consumption of the c ar by about 10% based on the double accumulator hybrid hydraulic vehicle.