Detecting and Controlling Tank Resonance of Oil Immersed Power Transformers
* Presenting author
In oil immersed power transformers, tank resonance can add a significant contribution to the generated noise. In the current study, a systematic procedure to first detect the resonence in the tank and then controlling its effect on noise is presented. This is done by either shifting resonance frequencies or damping the resulting vibrations via optimizing additional outer stiffeners. The procedure consists of measurement, simulation and modelling. The study shows the ability to predict the natural frequencies of the tank with a high accuracy, which is validated by applying hummer-test in specific places on the tank walls. Noise measuremts are conducted before and after applying the outer stiffners on the transformer walls with and without radiators. Results show that by following the presented procedure for a case study transformer it is possible to reduce the noise by about 5 dB.