Study On Energy Management Strategy For Plug-in Hybrid Electrical Vehicle With CVT

The plug-in hybrid electric vehicle(PHEV), which could help to reduce theconsume of fuel and have longer pure electric mileage by using more energy fromelectrified wire netting, was the research focus in the world. It was the core technologyof PHEV to match the powertrain parameter rationally and to have the energymanagement strategy for better vehicle economy. Therefore, two main aspects,paremeter matching of powertrain and making the energy management strategy, wereresearched seriously. The specific content included the following parts:A novel parallel powertrain configuration was proposed based on analyzing thecharacteristics and capabilities of typical PHEVs. Then its work models were analyzedin detail. The theoretical calculation method and driving cycle comprehensive analyticapproach were used to match parameters of the powertrain critical components. Thesimulation model of PHEV was set up.The powertrain simulation model was built by using MATLAB/Simulink software:the simulation model of critical components was built, the principle of dynamic wasused to build the vehicle dynamic model, the driver model was built by using PIarithmetic.Power distribution and CVT ratio of different powertrain work models wereoptimized on the basis of considering equivalent fuel consumption efficiency andengine efficiency. A rule-based energy management strategy was built. Then thedynamic and economy of PHEV were checked by simulation model.To improve the complete vehicle economy further, the variable parameters energymanagement strategy was proposed based on driving cycle and trip distance, whichinfluenced the vehicle economy. The fuzzy Euclid’s degree of nearness was used tobuild the driving cycle prediction control strategy based on typical driving cycles.Toreduce the influence of trip distance, two trip distance modes, long trip mode and shorttrip mode, at least need be used for energy control strategy. The vehicle trip distancemode prediction was proposed by using fuzzy prediction, the trip distance and the SOCof vehicle start were inputs, the trip mode was output. The energy management strategyof switching key control parameters was put forward by using the driving cycleprediction control strategy and trip distance mode prediction control strategy. Eventually,a complete vehicle simulation model for energy management was built, the simulation results showed that, compared with the constant parameters strategy, the variableparameters energy management strategy could reduce the equivalent fuel consumptionmore than5%.