A Tank Resonance Model for Power Transformers

During the factory acceptance test, the sound levels are measured. If the measured sound levels exceed pre-specified values, modifications must be made to the transformer’s active part or tank. Tank resonance at twice the main power frequency and its higher harmonics, if it occurs, is one of the main reasons of the amplification of the generated sound levels. Therefore, it is preferable to know in the early design stage about the occurrence of tank resonance and propose reliable solutions. The current study presents a newly developed model for calculating the mode shapes and the corresponding eigenfrequencies of the tank. Finite element simulations and an impact hammer test are conducted on a case study transformer to validate the model results.