A New Field-Data-Based EAF Model for Power Quality Studies

A new electric arc furnace (EAF)-specific model based on field measurements of instantaneous furnace voltages and currents has been proposed. This model presents the dynamic behavior of the EAF system, including all parts, i.e., the EAF transformer, the secondary circuit, the electrode movements, and the arc. It consists of a cascade connected variable-resistance and -inductance combination to represent the time variation at the fundamental frequency and a current source in parallel with it to inject the harmonics and interharmonics of the EAF current. The model takes into account several typical tap-to-tap periods of the specific EAF operation. This model is particularly advantageous for power quality (PQ) analysis and development of flexible alternating current transmission system solutions for PQ problem mitigation of a given busbar supplying single- or multi-EAF installations. The validity of the proposed model has been verified by comparing EMTDC/Power Systems Computer-Aided Design simulations of the model with the field measurements. The results obtained have shown quite satisfactory correlation between the proposed model and the actual EAF operation.