Noise and Vibration Analysis of Integrated Two-Speed e-Powertrain System for Electric Vehicles

This paper presents a detailed noise and vibration analysis of an integrated two-speed e-powertrain system for electric vehicles. Finite element-based simulation model of the e-powertrain system is established with major electromagnetic and mechanical excitations as inputs. Order interference analysis is conducted at the very beginning to avoid system resonance. Shaft natural frequency and modal analysis are used to check specific areas that are easier to be excited at certain frequencies than others. Both methods of housing acceleration response and mean square velocity response to electric motor and gearset transmission error (TE) harmonic excitations are applied in the vibration analysis. Two major areas including motor end cover and gearbox oil sump are identified and optimized to de-risk potential noise issues. System noise, vibration and harness (NVH) tests are completed in the semi-anechoic chamber to verify both vibration and acoustic noise simulation results.