Electric arc furnace transformer secondary circuit calculations

This paper demonstrates a procedure for calculating stress and temperature in the secondary high current circuit of a modern electric arc furnace. At the beginning, the separate parameters that form the electric circuit from the furnace to the bushings of the electrodes are determined. The analysis of these parameters allows the selection of the optimum operational point of the furnace. Thermal and stress analysis of the transformer secondary delta closure is further performed. The procedure is given in detail with all the required equations and is illustrated on a real 110-ton furnace with a 110 MVA transformer.