Research On Power-train Matching And Control Strategy Of Plug-in Hybrid School Bus

With the rapid growth of car ownership, the energy crisis and environmental problems havebecome increasingly prominent，The development of hybrid cars get strong support from alllevels of government, automotive enterprises and research institutions.School bus is an importantpart of the automotive market, which has get more and more people’s attention. Currently, hybridcars, hybrid electric hybrid buses and off-road vehicles have been widely studied, but the plug-inhybrid school bus of research is not particularly deep. Plug-in hybrid (referred PHEV) is a newtype of hybrid electric vehicles, in particular, it can be charged by using an external power grid,It not only retains the traditional advantages of hybrid cars, but it is also much prominent inpower, energy conservation and endurance capacity.In this paper, taking a school bus car asreference models, study the plug-in hybrid in aspects of its.First, according to the operating conditions of the school bus and body structurecharacteristics,and through the comparison of the powertrain structure of the series, parallel,hybrid, I have determined the plug-in hybrid school buses using tandem power structure.As aplug-in hybrid electric bus, the biggest advantage is that we premise to ensure the power in theschool bus and improve fuel economy and reduce exhaust emissions. To achieve this goal,through mathematical calculations, we decided to adopt the high power motor and small powerengine.The battery is one of the most important parts of plug-in hybrid electric bus, so the cellselection is particularly important. Due to the use of external power grid for charging, and ensurea single charge endurance distance greater than50km, so the battery will need a larger capacity.As the power system using series hybrid system, the motor as the only driving source, the batterycharge and discharge frequency is very high. According to the above requirements, through thecomparison of the different performance of battery, I decided to adopt the lithium-ion battery asthe battery. Temperature as an important influencing factor of the battery, in order to guarantee the performance of the battery and prolong life, In this paper, I have designed the thermal systemof battery.Control strategy is the key research content about plug-in hybrid electric bus, it is the keyfactor to improve fuel economy and reduce emissions., through the study of different controlmodes, decided to adopt the switch control strategy, it can make the engine always in the mosteconomic regional operation, and avoid starting the engine at low speed frequentlyinefficient.Finally, under the environment of MATLAB/SUMILINK, I carries on two times ofdevelopments on ADVISOR, and establish a plug-in hybrid electric bus model, I do simulationsin the NEDC cycle of the typical.And made a more detailed description of the two developmentin ADVISOR. Through the analysis of the simulation results, the fuel economy and emissionperformance is greatly improved, and provides reference and theoretical basis for the research onthe school bus in plug-in hybrid aspect in china.