Modelling and Control of Electrode System for an Electric Arc Furnace

This paper presents a new application of a fractional order control system which controls the input energy to a three phase electric arc furnace. Graphite electrodes are used to convert electrical energy into heat via phase electric arcs. Constant arc length is desirable as it implies steady energy transfer from the graphite electrodes to the metallic charge in the furnace bath. With the charge level constantly changing, the electrodes must be able to adjust for the arc length to remain constant. A fractional order PI controller has been developed to be responsible for the vertical adjustment of the electrode tip displacement according to specified set-points to ensure that the arc lengths remain as constant as possible. The simulation results show that the system performances are satisfactory using the proposed method. Keywords— Electric Arc Furnace, Electrode Tip Displacement, Fractional Order Controller.