Control Strategy Research And Vehicle Performance Simulation Of HEV Based On CVT

New energy vehicle has become an important direction of the development of theautomobile industry in China. Hybrid vehicle is the necessary choice of new energystrategy in China. From the perspective of reducing the fuel consumption and powerconsumption of the vehicles, for the complex structure of today’s hybrid vehicles, anew structure of two driving axles is proposed and meanwhile a deeply study on thetechnology of the hybrid vehicle drive control strategy is conducted.The mainly content is as follows: Firstly, a car is improved to be the new hybridmodel of two driving axles through the hybrid driving system design of tractioncoupling. According to the demands of vehicle performance, the parameters oftransmission system are matched and the key components are reselected. Secondly,the vehicle control strategy is built up on the basis of the logic threshold method.Keeping engine working in the high efficiency area all along through the reasonabledistribution of engine and motor’s torque by setting threshold value, can reduce thefuel consumption and then reduce the air pollution. This control strategy andparameter matching can meet the opening target. And adjusting the parameters incontrol strategy to different driving conditions is easy to implement. This study alsointroduces some vehicle driving modes, including power driving mode, engine drivingmode, engine driving with motor assist mode, generating mode and brake energyrecovery mode, etc. These modes can be simple switched each other on the basis ofthe logic threshold method. Finally, based on Matlab/Simulink, the two driving axleshybrid vehicle model is built. Simulation was carried out on the model in differentdriving conditions. The grade ability, acceleration time, power consumption, fuelconsumption，motor temperature variation and the engine working point can beobtained by simulation. The simulation results show that, this new hybrid drivingsystem can retain engine and motor working in the high efficiency area. It improvesthe fuel efficiency, and has obvious advantage in energy-saving and emission reducing,etc. The feasibility of control strategy are verified by the improvement of vehicleperformance and fuel economy.