Study on electromechanical coupling inherent vibration characteristics and parameter influencing law of EMT system used in HEV

As high-speed, heavy-load, and high-power density are realized in hybrid electric vehicle (HEV), the electromechanical coupling inherent vibration of electromechanical composite transmission (EMT) system becomes the bottleneck in this study area. To reduce vibration, the analysis of inherent vibration characteristics of EMT system and parameter influencing law of mechanical-electro-magnetic parameter is key. Here, an electromechanical coupling dynamics model is established considering multi-source excitations, and the inherent vibration model is obtained. Based on this inherent vibration model, firstly, the inherent vibration frequency and mode with and without electromagnetic effect of EMT system are studied and summarized. Secondly, the resonance speed of EMT system is identified based on Campbell diagram and modal energy method. Thirdly, the inherent frequency trajectory and variation law affected by PMSM parameters (inner power factor angle (IPFA), armature current, stator-rotor eccentricity) and the mode mutations phenomenon of inherent frequency trajectory caused by PG parameter (connecting, gear meshing, and bearing support stiffness) are studied. This study results provide a reference for the modeling and analysis of inherent vibration characteristics, as well as the design and optimization of mechanical-electro-magnetic parameter of EMT system.