Comprehensive vibration generation model of transformer winding under load current

This study proposes a comprehensive model to investigate winding vibration characteristics. The radial vibration model is firstly established based on the Euler–Bernoulli beam theory, and the radial acceleration is found to be the second derivative of deflection under the quasi-static load. The fluid-loading effect of oil on winding vibration is then investigated through experimental modal analysis and finite element method. This effect leads to the decrease of natural frequencies and the increase of damping ratios. The harmonic response of axial winding vibration at 100 Hz shows the symmetry distribution that vibration on the one quarter and three-quarters of the winding height are larger than other positions. The radial acceleration is not affected by the clamping pressure, whereas the axial acceleration is in a reciprocal relationship with it.