A Novel Approach for Rapid NVH Analysis of an Electric Motor Using an Integrated Workflow

The electric motor is one of the main sources of noise in an electric powertrain. In traction motor, both radial and tangential electromagnetic forces on stator teeth contribute to the NVH of the powertrain. These forces are mainly the result of lower order and higher order frequency harmonics in the air gap. In this paper, an integrated workflow is presented for rapid e-NVH analysis. Additionally, a case study from a motor manufacturer Sona Comstar of a 10 kW permanent magnet synchronous motor (PMSM) being used for non-automotive traction application. This workflow leverages the use of 2D FE analysis methods and ray acoustics for a fast-running NVH simulation. In the first step, calculation of the radial and tangential electromagnetic forces using a 2D finite element electromagnetic simulation tool is presented. These electromagnetic forces are calculated at a set of pre-defined operating points on the torque-speed boundary and further imposed onto the stator for vibroacoustic analysis in the next step. Finally, the results of e-NVH analysis of the machine are compared with test bench measurement data, highlighting the benefits of the integrated workflow. In conclusion, this paper aims to demonstrate a novel method for rapid NVH analysis and lay the basis for future electromagnetic NVH performance optimization.