Analysis of vibration characteristics of e-CVT powertrain

Hybrid electric vehicle has more than one power resources, which has changed the vibration characteristics of powertrain. It is essential and necessary to study the resonant frequency of hybrid powertrain, in order to optimize the stiffness match and avoid resonant failure as well. A new e-CVT hybrid system is analyzed to find the resonant frequency of powertrain. All possible driving modes of vehicle are confirmed according to the control strategy, and then vibration models are built. As the speed of engine is independent on vehicle speed, an assistant ratio parameter is introduced to build the parametric vibration model. The influence of ratio and damper stiffness on powertrain resonance is investigated. The resonant speed can be reduced out of engine working speed range with lower damper stiffness. The conclusion of the analysis can be used to guide the powertrain stiffness match and damper design.