Electro-mechanical coupling dynamics analysis and model updating of an electric drive system for new energy vehicles under multiple operating conditions

The escalating demand for increased torque and power density in electric drive systems for new-energy trucks intensifies the technical challenges associated with vibration, noise, and dynamic reliability. This study establishes a high-fidelity electro-mechanical coupling model for an integrated e-drive, combining a vector-controlled interior permanent-magnet synchronous motor with a two-stage gearbox. The model incorporates electromagnetic torque ripple, time-varying mesh stiffness, gear backlash, and transmission error. Bench tests under multiple operating conditions provide validation data. Global sensitivity analysis identifies input shaft stiffness and gear mesh parameters as most influential. These parameters are then updated via Particle Swarm Optimization, effectively curtailing simulation errors for key dynamic responses from over 20% to less than 8%. The updated model elucidates critical coupling dynamics: dynamic loads surge to 2.5 times nominal during rapid acceleration; severe impacts occur during gear re-engagement in regenerative braking; and a pronounced mid-frequency whine arises from modulation between electromagnetic and mechanical excitations. The validated high-precision framework offers a robust foundation for the design, optimization, and NVH mitigation of next-generation electric drive system.