Dynamic Response of Power Transformer Tanks

Noise reduction has been imperative in urban and overall heavily populated areas, aiming to decrease the impact of undesirable or unwanted sound in the human and wildlife's health and wellbeing. In addition, transformers need to be nearer urban agglomerates, considering the current challenges in power distribution networks due to increasing power needs and as more energy is being produced, stored, and distributed closer to the final consumer. This equipment should not impact significantly people's life, and so, lower noise levels are required, ensuring a quieter performance. Radiated noise from a power transformer is mainly due to the induced vibrations in its active part, which are caused by magnetostriction effects and Maxwell forces in the iron core (no-load noise), and by Lorentz forces in the windings (load noise). These vibrations promote a noise spectrum composed by even harmonics of the power frequency, typically 50 Hz or 60 Hz. The transformer's enclosure, tank and oil also have an important impact, positive or negative, on the irradiated noise to the environment. This article addresses the vibration and harmonic response of power transformers tanks, evaluating the effect of nonconventional geometries on the radiated power level. Additionally, based on the obtained results, the contribution of several tank components is quantified, allowing the main irradiated power sources to be identified.