Multifield coupled dynamics modeling and vibration characteristics of electric-vehicle electric drive systems

To investigate the multifield coupled vibration properties of electric-drive systems of electric vehicles, an improved equivalent magnetic network model of a permanent magnet synchronous motor suitable for variable speed/load and other non-stationary conditions is established by considering the nonlinear factors such as stator slotting, pole distribution, and magnetic saturation. On this basis, a machine-electric–magnetic multi-field coupling dynamics model of the electric drive system is established by comprehensively considering the gear transmission error, time-varying meshing stiffness, etc. The laws affecting the dynamic properties of the electric drive system under excitation of the internal nonlinear factors and external load are investigated. Research shows that electromagnetic excitation exacerbates the vibration amplitude of the gear. Mechanical excitation modulates the current frequency. The system vibration response amplitude trend is consistent with the current low-frequency harmonic components that can be used to monitor the system vibration state. External shock loads have the greatest impact on the vibration of the first-stage active gear and secondary-stage driven gear. The coupling effect of the motor and gear can effectively suppress the shock oscillation caused by a sudden change in the load.