An Experimental Approach for Understanding V-I Characteristic of Electric Arc Furnace Load

Abstract

Electric Arc Furnaces (EAF) are nonlinear loads causing power quality problems on the systems they are connected to. The main reason of EAFs causing power quality problems is the nonlinear characteristics of the electric arc. In this study, dynamic working characteristics of electric arc furnace load at Sivas Iron and Steel Incorporated Company (SIDEMIR) operating with 60 MVA EAF have been experimentally examined by HIOKI 3197 PQ analyser. Utilizing the measured dynamic load curves, mathematical equation and proper parameters have been determined for modelling electrical arc with the help of curve fitting methods on Matlab program. Also by modeling a phase equivalent of the system and harmonic filters existing on the system, a time domain model has been formed and with this model, harmonic effects of the EAF have been examined with Matlab/Simulink. Simulation results show that the presented model can be used for examining PQ and voltage harmonics problems caused by EAF loads.

Improvement of electromagnetic compatibility and efficiency of power supply circuits of electric arc furnaces in nonlinear asymmetric modes

“…The basis for its choice is the results of comparing the stress diagrams obtained during the studies on the model with experimental data. According to published diagrams of arc voltages [17,18], the relative value of arc ignition voltage is in the range of 1.24-1.76.…”

“…For the given curves, the ratio between the voltage of the arc ignition and the voltage of the arc at the moment of its maximum current (relative voltage of the arc ignition) has the following values for the indicated 7 periods: 1.26; 1.27; 1.35; 1.47; 1.59; 1.63 and 1.68. According to the experimental data, during the melting period, this ratio of arc stresses behind the diagrams in [17] is in the range of 1.24-1.76, and for [18] from 1.46 to 1.6. Thus, in terms of the relative arc ignition voltage, all considered the value of the exponent n make it possible to obtain the shape of the arc voltage, the characteristics of which are consistent with the experimental data.…”

“…To substantiate the reliability of the reproduction of the arc voltage shape by the considered arc models, the results obtained were compared with the experimental data of the arc voltage functions. The time diagrams of the arc voltage were developed [17], obtained from the measurement data on the secondary winding of the transformer, as well as the experimental data of the arc voltage for a furnace with a transformer power of 60 MVA [18].…”

A Mathematical Model of Electrical Arc Furnaces for Analysis of Electrical Mode Parameters and Synthesis of Controlling Influences

“…On the other hand, when studying the influence of EAF on the electrical network, the processes in the EAF electrode movement are not taken into account, using Volt-Ampere characteristics of arcs at given values of arc length or given laws of its change [1][2][3]8,[17][18][19]. In both cases, the Volt-Ampere characteristics of the arc are used, and therefore it is not surprising, that much of the work is devoted to the modeling of the electric arc [7,9,[20][21][22]. Thus, a significant part of EAF models used in the control systems studing, does not take into account nonlinearities and changes in parameters.…”