Torsional characteristics optimization of a damper with a torque limiter in a hybrid electric vehicle based on multi-DOF powertrain bond graph modeling

Dampers with torque limiters (DTLs) are widely used components in hybrid powertrain systems because they can effectively mitigate torsional vibration problems. In this paper, a multiple-degree-of-freedom (multi-DOF) powertrain bond graph modeling method is proposed to optimize the torsional characteristics of a DTL in a compound planetary set power-split hybrid electric vehicle (HEV). First, the structure and characteristics of a hybrid powertrain system and DTL were analyzed. Based on the bond graph principle, a 10-DOF dynamic model of the powertrain for the power-split HEV was established. This model precisely represents the torsional vibration phenomena experienced by the powertrain under idling and acceleration conditions. After investigating the impacts of the torsional characteristic parameters of the DTL on the torsional vibration under idling and acceleration conditions, an optimization scheme for the DTL was developed. Finally, the results of real vehicle tests demonstrate that the optimized DTL exhibited a vibration attenuation performance improvement over the pre-optimized DTL of more than 60%; this result validates the effectiveness of the proposed optimization scheme.