Variable damping mechanism and verification of the torsional damper for a parallel-series hybrid electric vehicle

The torsional vibration of hybrid electric vehicles (HEVs) powertrain coupled with multiple power sources is more complex, and the hysteresis torque requirements are different under different working conditions. Therefore, this study investigates the impact of the hysteresis torque value on damping performance for torsional dampers under diverse working conditions through modeling and simulation. A configuration for a torsional damper that enables variable hysteresis torque in different working conditions is proposed. Simulation results demonstrate that the variable hysteresis torsional damper reduces angular acceleration fluctuation amplitude by 54.5% during motor-assisted engine starting and by 20.2 % during combined drive conditions compared to traditional dampers, effectively attenuating vibration under two different working conditions. The proposed variable hysteresis torsional damper configuration is verified to meet design requirements for different working conditions.