Eddy Currents in Structure Surrounding Large Current Bushings of a Large Capacity Transformer

An experimental analysis of eddy current phenomena in the structure that surrounds the large current bushings of a large capacity transformer and a means of preventing local overheating in that structure are presented. A basic model with a conducting current of about 20 kA was constructed to investigate eddy current phenomena. A construction in which all the components of the model were connected electrically to each. other, so as to cause bus currents to be surrounded by eddy currents, was found to prevent local overheating. The construction suggested by the experiments carried out with the basic model was applied. to the development of a full-size model with a conducting current of about 30 kA. It was confirmed in experiments that no local overheating occurred in the full-size model. Some eddy current calculations were also performed with the basic model. The possibility of calculating eddy current distribution in complicated constructions was also discussed.