Control strategy for clutch engagement during mode change of plug-in hybrid electric vehicle

The plug-in hybrid electric vehicle (PHEV) has various driving modes used in both internal combustion engine and electric motors. The EV mode uses only an electric motor and the HEV mode uses both an engine and an electric motor. Specifically, when the PHEV of a pre-transmission parallel hybrid structure performs mode changing, its engine clutch is either engaged or disengaged, which is important in terms of ride comfort. In this paper, to enhance the mode changing process for the clutch engagement, a PHEV performance simulator is developed using MATLAB/Simulink based on system dynamics and experiment data. Vehicle driving analysis is carried out of the control logic and properties of the mode changing. A compensated torque is applied during the mode change. This results in the rapid speed synchronization with the clutch although the trade-off relationship of the mode change. In addition, the mode changing is conducted through the transmission shifting process to rapidly synchronize with speed. The control strategy implemented in this study is shown to improve the drivability and energy efficiency of a PHEV.