Integrated Approach to Electro-Mechanical System NVH Analysis

The paper presents an integrated approach to system NVH analysis, which gives an insight into the system response in an EV driveline due to electrical and mechanical excitations; namely gear transmission error, electrical machine torque ripple, and stator tooth forces. It is shown through simulation the importance of considering the complete system when evaluating NVH performance. This is demonstrated by examining how the response of the drivetrain is affected by electro-mechanical interactions. The simulation will demonstrate the importance of considering influences such as system boundary conditions, the representation of bolted connections and manufacturing tolerances. Furthermore, the paper will present validation results of NVH testing performed on a prototype drivetrain, developed to meet the system requirements of a battery EV city car as part of an EU funded project. Good agreement is shown between measured and predicted response due to both gear and electrical machine excitations.