Vibration distribution characteristics on oil-tank surface of a single-phase transformer

Power transformer vibration and noise not only affect the equipment life, but also seriously pollute the environment. The noise is proportional to the surface vibration velocity of transformer. The objective of this work is to measure vibration velocity distributions on oil-tank surfaces of a power transformer and to investigate relationship of vibrations between different points. No-load test and load test were conducted on a single-phase transformer respectively. The oil-tank surfaces were divided with small grids and a portable digital vibrometer (PDV) was conducted to measure the vibration velocity on every point. The experimental results show that the velocity on a specific point is steady and periodic. The frequencies of vibration mostly converge from 100–500 Hz while the amplitude of vibration reach maximal at 100 Hz. Velocities of different measure points on a surface are quasi-synchronous and have same phases or reversed phases so that the velocity distribution presents as a wave shape. The positions with maximum vibration amplitude at different frequencies are different. This can provide the guidance for the application of vibration method in monitoring the condition of transformer winding.