Switching control from motor driving mode to hybrid driving mode for PHEV

The research object of this paper is a single-shaft parallel hybrid electric vehicle (PHEV). A noticeable jerk or torque fluctuation in the hybrid powertrain may result in the vibration of the drivetrain and an unpleasant driving sensation during transition from the motor driving mode to the hybrid driving mode. According to the analysis of the vehicle dynamics, the switching process is divided into three stages, that is, engine cranking phase, speed synchronization phase and torque switching phase, respectively. By analyzing the vehicle dynamics of the different switching phases, different mode switch control strategies are proposed for every process to reduce torque fluctuation and achieve the aim of restraining chattering. Taking MATLAB/SIMULINK as the platform, the vehicle control simulation model has been built to verify the proposed control strategy. The results demonstrate that the dynamic control algorithms can ensure smooth mode switching and good the drivability on the premise of good dynamic performance, which shows the validity of the proposed control algorithms.