On the Use of Vibration Synthesis to Ease Electric Machine Powertrain Design

This paper provides e-machine designers a critical study on the vibration synthesis algorithm that calculates the vibrations of an electric machine responsible for magnetic noise. It separates the computations into two distinct categories: Offline and online. Comprehensive parameters are input to an offline simulation system where generic magnetic forces and vibration transfer functions are created. This generic data combined with operational loads from system-level simulations refers to the online simulation environment. The methodology is applied to an interior Permanent Magnet Synchronous Machine (PMSM), and compared to the standard procedure where run-up simulation can become time-expensive due to the extensive use of Finite Elements (FE) methods. Vibration results show discrepancies of harmonic amplitude content essentially coming from the force truncation made in the vibration synthesis, for which a selection protocol is proposed. Yet the offline simulations permit to front-load the computational efforts thus implying the use of the technique in system-simulation environments.