Tangential Electromagnetic Force Array on the Vibration and Noise of Electric Axle for New Energy Vehicle

It is generally accepted that the vibration and noise of electrical motors mainly depend on radial electromagnetic forces. However, the relationship between electromagnetic forces and system modes becomes special when integrating the electrical motor into a coaxial electric axle (eAxle). This paper proposes a phase-based tangential electromagnetic force array analysis method to explain and optimize the noise spikes in a coaxial eAxle which is driven by a permanent magnet synchronous motor (PMSM) with a step-skewed rotor. Its electromagnetic force on each stator node is decomposed into radial and tangential forces as inputs for structural finite element simulation. Based on their contributions to the noise, the torsional vibration and noise of the eAxle are correlated with the tangential electromagnetic force array. Thus, the coupling effect of excitation and response is illustrated, and the electromagnetic force array could be optimized more targeted.