Research On Energy Strategy Of Hybrid City Bus And Energy-saving Evaluation

In recent years, with the increasing deterioration of the environment andresources problems, energy conservation and emissions reduction problem putforward higher request to the development of automobile industry. Developmore highly effective energy conservation and environmental protection meansof transport has become each big automobile manufacturers and researchinstitutions at home and abroad need to resolve. Hybrid vehicles, as one of therepresentative model of new energy vehicles, has made great breakthrough intechnology. But due to different configuration of the hybrid electric vehiclestructure, it still exists a great deal of oil-saving rate room to improve, which ismainly dependent on vehicle energy management strategy. Therefore, researchon energy management strategy and Evaluation means of the saving ratebecome a hot research field of hybrid vehicles.Firstly, in this paper, Four kinds of power system structure are studied,which are series, parallel, coaxial parallel connection, mixed type. Analyzedthe working principle of each structure and adopt energy management strategy.the four configurations of hybrid city bus in China under the typical workingcondition of city bus circular real vehicle fuel consumption comparison test hasbeen done, the results show that the four kinds of hybrid city bus relative toconventional fuel oil-saving effect significantly, and the mixed typeconfiguration has the lowest fuel consumption, the coaxial parallelconfiguration has the second.Secondly, in the Matlab/Simulink environment, coaxial parallel hybridelectric vehicle energy consumption model and the energy managementstrategy of city bus model are build, Energy management strategy selection issimple but closer to the actual application logic threshold strategy, with thebattery SOC value and the power source output torque as the main referencevariables, no active charging energy distribution strategy and take activeenergy distribution strategy of charging two energy distribution strategy aredeveloped. Through real vehicle tests compared with the simulation calculationmethod, the energy consumption of the vehicle simulation model is verified thereliability and accuracy of the premise, which show that the prototype theoryfuel ascension space was28.46%.Finally, this paper expounds the current hybrid city bus fiscal subsidies onthe basis of “oil-saving rate” and “the biggest electric power ratio” isunreasonable. The published359subsidized products which are “oil-savingrate more than40%, the highest rate to100%more fuel-efficient models”. Butin seven cities of our country the typical bus lines of actual operation of fuelconsumption measurement are researched and the conclusion is: the hybrid city bus fleet compared with conventional diesel team, oil-saving effect at about19.02%on average. Released on this basis, the main reason of the big gapbetween the oil-saving rate and the actual test oil-saving effect is analyzed,which is based on self oil-saving rate method to calculate the longitudinalcomparison. In this paper, the way of transverse comparison method isproposed, and the technical scheme of subsidies of transverse compare of theheavy commercial vehicle fuel consumption limits is designed.