Study on the torsional vibration of a hybrid electric vehicle powertrain with compound planetary power-split electronic continuous variable transmission

A torsional vibration dynamic model is established with the commercial software ADAMS to predict the torsional vibration characteristics of a compound planetary power-split hybrid electric vehicle. By calculating and simulating the built model in ADAMS, the natural frequencies and corresponding modes are obtained. The results agree well with previous work, which derives the conclusions by solution of the system dynamics equations of hybrid driveline. Moreover, the main factors that influence the torsional vibration of the powertrain under the excitation of engine and electric motors are analyzed by the forced vibration analysis. The calculated results show that the low frequencies occur mainly in the torsional vibration of wheels and vehicle, while the high orders are related to the torsional vibration of differential, sun gears and planets. The results also show that the amplitude of torsional vibration of driveline is the lowest when the damping and stiffness of torsional damper are 15Nms/rad and 618Nm/rad respectively, the halfshaft stiffness is 2760Nm/rad and the rotational inertial of engine is 0.42kgm(2). The research can be used to support the further development of the power-split hybrid electric vehicle.