Experimental and numerical investigations on the dynamic response of a power transformer

In the manufacturing unit, there is a need of an accurate and reliable numerical tool to predict noise radiation from transformer. The first step to achieve this is to have a proper modal analysis of the active part (winding+core+clamping system). An impact test was performed on a 30 MVA power transformer unit and resonance peaks were identified from the FFT plots. Also, Operational Deflection Shapes (ODS) were extracted to visualize the displacement pattern of the test object. Moreover, the transformer unit was electrically energized, and vibration levels were measured with Polytec 3D scanning laser vibrometer. A detailed numerical model was developed in COMSOL Multiphysics, and very good agreement was seen between the numerical and measurement results.