Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces

Power usage in ultrahigh-powered electric arc furnaces requires considerably more investigation into system parameters, furnace secondary circuit analysis, and operating characteristics than previously given to normal powered electric arc furnaces. The power input must be analyzed from the infinite electric utility bus to the arc at the electrode. All interested parties must participate in the analysis to assure a mutual understanding of each other´s problems. Various high-voltage systems are compared along with power factor correction applications. An 18-ft (5.5-m) 80-ton (72.6-metric tons (MT)) furnace has been selected for detailed analysis with a 50-MVA furnace transformer. In addition to electrical considerations, the power melting profile and associated refractory erosion is also subjected to analysis in this review. The analysis indicates that with proper application, ultrahigh-powered electric arc furnaces will provide increased production with reasonable refractory erosion.