STUDY ON DYNAMIC CHARACTERISTICS OF ELECTROMECHANICAL COUPLING IN MODE SWITCHING PROCESS OF MULTI-POWER TRANSMISSION SYSTEM CONSIDERING INTERNAL AND EXTERNAL EXCITATION

Abstract

The compound power-split hybrid transmission system is usually driven by the internal and external excitation to cause the impact or vibration of the transmission system. In this paper, a pure torsional nonlinear dynamic model of electromechanical coupling is established for a compound power-split hybrid transmission system. The dynamic torques outputted by the power sources are used as the external excitation of the planetary gear power coupling mechanism, the meshing shocks caused by gear backlash in the gear mechanism are taken as the internal excitation. From the perspective of elastic dynamics, the influence on the dynamic characteristics of the electromechanical system is analyzed by considering the interaction of internal and external excitation during the mode switching from the pure electric mode to the hybrid mode. The results show that, with the decrease of the dynamic torques of motors, the external excitation will cause the internal excitation in the form of meshing impact between the planetary gears and the sun gears. The influence of the interaction of the internal and external excitation on the mechanical properties of the dynamic coupling mechanism increases with the increase of the gear backlash. However, the influence on the dynamic characteristics of power sources is not obvious.