Modal Analysis for the Vibration of the Dry-Type Transformer in the Offshore Oil Exploitation Power System

The transformer windings may be subjected to excessive electromagnetic force during the short-circuit process. Under the electromagnetic force, the transformer windings may be deformed. The transformer structure plays a crucial influence on the deformation degree. In this paper, the modal analysis method is used to verify the rationality of a 35 kV epoxy resin cast dry-type transformer’s structure that is used in an offshore oil exploitation power system in China. The finite element model of the transformer is established. After the appropriate materials are set to the components of the transformer, the various modes of the transformer vibration are obtained based on the simulation analysis. According to the form of electromagnetic force subjected by the windings, both natural frequencies and vibration modes of each transformer component are obtained, and used to evaluate the influences of the electromagnetic force on the windings. Finally, the structure design of the studied transformer is analyzed based on the above analysis and simulation results.