Research On Parallel Hydraulic Hybrid Power System Of Engineering Vehicle

Vehicle energy-saving and emission-reduction technology has been the focus of research inautomotive engineering field.As one of the branches,the vehicle hydraulic hybrid technologyhas also been concerned by domestic and foreign automobile manufacturers and researchinstitutions.The research of vehicle hydraulic hybrid technology is the front topic of thedevelopment of energy saving technology in the field of automobile engineering at home andabroad.Compared with the hybrid electric power system,the hydraulic hybrid power system hasthe advantages of high power density,high energy conversion rate and environmentalfriendliness,which makes it have a good prospect in engineering vehicle field.Parallel system isbasically unchanged in the original car structure,the addition of a set of additional systems toform an auxiliary power source.Compared with the series system,the parallel system has theadvantages of small power,small system,low cost,simple structure and good reliability.It isespecially suitable for medium and heavy vehicles with frequent starting and stoppingconditions.In this paper,the new M3000 dump truck is studied in this paper.The main research workis as follows:1.This paper has carried on the principle design of the parallel hydraulic hybrid powersystem of the engineering vehicle.On the basis of achieving the function of energy recovery andenergy release,the electro-hydraulic control system focus on solving the technical challenge ofoil leakage and oil temperature in hydraulic system,overflow loss during energy releasing andaccelerating backwards when the vehicle starts on the slope but occurs the phenomenon ofdriving backward and so on.2.This paper has carried out the the parameters matching,modeling and simulation analysisof hydraulic hybrid dynamic system.First of all,based on vehicle parameters,vehicle operatingparameters,vehicle operating conditions and operating characteristics of the accumulator,hydraulic pump/motor,accumulator and other parameters were matched.Secondly,themathematical model of the system is established,which is used to simulate the running status of the hybrid vehicle,the energy output of the engine and the hydraulic hybrid power system,and the energy saving efficiency.3.Based on the hydraulic hybrid power system designed in this paper and operating conditions of vehicle,the control method of energy recovery and energy release is studied deeply,and a two-stage energy management control strategy based on condition identification is proposed.4.The prototype of parallel hydraulic hybrid powertrain was developed,and the actual vehicle running experiment and fuel efficiency test were carried out.According to the experimental data,the dynamic performance and energy efficiency of the vehicle under different working conditions and different working conditions were analyzed and studied.The result of the real vehicle running test shows that the system saves 40%.