Research On Design And Control Of Parallel Hydraulic Hybrid Power System Of Heavy-load Vehicle

With the increasing energy crisis and environmental pollution,the global people's awareness of energy conservation and emission reduction is increasing.The popularity of automobiles consumes a lot of energy and causes pollution.Therefore,the development of energy-saving and environmental protection automobiles has become a world consensus.Hydraulic hybrid system technology of automobile has the characteristics of high power density,high energy conversion efficiency,safety,cleanliness and low cost.It has become a research hotspot of governments,scientific research institutions and automobile manufacturers in various countries.This topic comes from the hydraulic hybrid power transformation project of tank-holding truck cooperated with Baosteel,Sinopec.The object of the transformation is BTC-35,which works at low speed and heavy load for a long time and needs frequent start-up and shutdown.This paper is as follows:(1)Principle Design of Parallel Hydraulic Hybrid Power SystemThe design scheme of the whole vehicle system is put forward on the basis of the unchanged structure and configuration of the original tanker.In addition,an electro-hydraulic control system matching the auxiliary power source(hydraulic pump/motor)and accumulator is designed,which can realize the functions of energy recovery,energy release and engine efficiency optimization.(2)Hydraulic Hybrid Power System Parameter Matching Research and Modeling and Simulation AnalysisBased on the parameters of vehicle components,operation parameters and design objectives,the parameters of hydraulic pump/motor,high-pressure accumulator,low-pressure accumulator and refueling pump are calculated.Secondly,the mathematical model of hybrid power system is established,and on the basis of it,the traditional vehicle model and hybrid vehicle model are built by using AMESim software.Under the same working conditions,the different models are simulated and analyzed.Vehicle fuel consumption under component parameters.(3)Research and simulation analysis of two-stage hybrid control strategy for hydraulic hybrid power systemBased on the system principle and parameter matching,a two-stage hybrid energy control strategy is proposed.Combining with mathematical theory,this paper establishes the MATLAB model of hybrid electric vehicle,and simulates and analyses the energy output of engine and hydraulic pump/motor and the energy saving effect of the whole vehicle.The simulation results show that the energy saving effect is ideal for different vehicle weights and speeds,and the energy saving efficiency can reach about 35%.(4)Development and experimental study of prototype carAccording to the principle and control strategy of the hydraulic system of the vehicle,the transformation of the hybrid electric prototype car of the tank holder was completed,and the experimental research was carried out,including braking performance experiment,energy conversion efficiency experiment and road real vehicle experiment.The actual vehicle operation results show that the fuel-saving efficiency of the system is 31.2%.