Engine clutch control algorithm during mode change for parallel hybrid electric vehicle

In this study, an engine clutch control algorithm that can minimize the torque variation is suggested for a parallel hybrid electric vehicle (HEV). A performance simulator was developed using the powertrain model of the HEV and a test bench was designed and constructed to evaluate the mode change characteristics of the HEV. The clutch kissing point was measured using the test bench, and an engine clutch control algorithm considering the torque variation was proposed based on the test results. The proposed control algorithm can minimize the torque variation during mode change from EV to HEV by controlling the engine clutch in four steps depending on the vehicle condition.