Research On Energy Management Strategies And Simulation Of A Plug-in Hybrid Electric Vehicle

New energy vehicle has become an important direction of the development ofthe automobile industry in China. And plug-in hybrid electric vehicle (PHEV) is oneof the inevitable choices for the new energy strategy of China. In this paper, energymanagement strategies were studied based on metal V-belt continuously variabletransmission (CVT) in the light of the characteristics of a new designed PHEV fromthe perspective of the reduction of fuel consumption and emission. To verify theeffectiveness of the energy management strategies, a PHEV model was establishedand simulated by using forward-facing simulation on the Matlab/Simulink platform.The main contents are as follows:(1) The technical indexes, economic performance, dynamic performance anddrivable performance, of the PHEV based on CVT were studied, which was modifiedby a domestic compact car LF620. The power of internal combustion engine, thetype and the power of motor, and the type and the capacity of power batteries weredetermined by the matching calculation of the parameters of the power train toimprove fuel economy and emission in the premise of meeting the dynamicperformance indexes. And six modes of operation and energy flow of the PHEV wereanalyzed.(2) Energy management strategies of the PHEV based on CVT were studied byapplication of the method of dynamic logic threshold according to the performancecharacteristics of internal combustion engine and motor. And the control strategiesof mode switching, the control strategies of motor torque, and the control strategiesof hybrid CVT ratio were studied.(3) The forward-facing simulation model of the PHEV based on CVT wasestablished by application of the methods of theoretical modeling and empiricalmodeling on the Matlab/Simulink platform. And the models of driver, internalcombustion engine, motor, power batteries, CVT, and dynamic model of the vehiclewere included in the simulation model.(4) Dynamic performance and economic performance of the PHEV based onCVT were simulated and assessed to verify the effectiveness of the energymanagement strategies in the light of dynamic logic threshold. The results ofdynamic performance show that the PHEV has good acceleration at low speed in the pure electric mode, and the PHEV has good dynamic performance in the hybridmode. And the results of economic performance show that the fuel consumption wasreduced by46.1%compared with the conventional internal combustion enginevehicle with an equivalent fuel consumption of4.26L/(100km).