Harmonic measurements and analysis in a modern steel manufacturing facility

Harmonics is a growing concern to both electric utilities and their customers. Nonlinear loads in large-scale industries are important causes for the harmonic currents and voltage distortion. In modern steel manufacturing facilities, Arc furnaces and rolling mill loads are the two major nonlinear loads. They generate significant harmonic currents that flow through the plant and utility power system. These harmonic currents cause system voltage distortion, power loss, additional heating and equipment failures. This paper presents a harmonic analysis in a modern steel manufacturing facility for ac electrical arc furnace (EAF) loads with static vary compensation (SVC) in both off and on states, and rolling mill loads with high frequency filters in both off and on states. Total harmonic distortion (THD) in voltage, 2^nd-25^th harmonics content in current are presented. Curves of RMS voltage, active power, and reactive power are also given. Box fractal dimensions are computed as an characteristic parameter for both evaluation of the complexity of measurement curves and characterization of EAF and rolling loads.