Abstract

This article demonstrates the use of a mathematical method to efficiently discriminate and visualize each circumferential vibration wave number involved in the yoke deflections of an electrical machine under electromagnetic excitations. This post-processing, which can be applied on both experimental and simulation data, allows to calculate the participation factor of each magnetic force wavenumber at a particular frequency. It is therefore a powerful visualization tool to understand the origin of magnetic vibrations and acoustic noise. The resulting graphs, called “spatiograms” as an analogy of the spectrograms done at variable speed, are based on the Discrete Fourier Transformation of the accelerations measured along the machine circumference. This paper explains the post-processing calculation and shows some numerical and experimental validation on both an asynchronous machine and a permanent magnet synchronous machine.

Preprint and full paper

The preprint can be found on ResearchGate.

Notes

The spatiogram post-processing is available in MANATEE simulation software. It can be applied to acoustic noise (plot_VS_ASWL_spatiogram) or directly to magnetic forces (plot_VS_Fr_spatiogram) responsible for magnetic noise and vibration of electrical machines.