Balancing the electrical parameters of the interleaved rigid current jaw of an ore-thermal furnace

Abstract

This article is devoted to solving the electrical engineering problem of using an ore-thermal furnace (OTF) as the main ferroalloy industrial unit. The secondary current jaw of such a unit should have minimal active resistance and inductive reactance, as well as balanced phase current jaws. The operating currents in OTF electrodes can exceed 100 kA. These currents are distributed between parallel wires. The rigid stationary current jaw from the transformer to the flexible current jaw is set up as a package of rectangular or tubular bus bars. According to the most frequently used current jaw scheme, electrodes carry the linear currents. Hence, bus package inductance can be reduced by interleaving the half-phase wires. There are many variants of interleaved package construction design. To select one of them, it is convenient to have a simple method for determining the active resistance and reactance values of bus packages. The power source position to one side of the furnace tank causes a significant difference between the phase bus package lengths, which leads to the total secondary current jaw unbalance. This unbalance involves noninform power dissipation in the OTF operating space and, therefore, a decrease in the OTF performance characteristics. The relationships between the bus package active resistance and reactance values and their geometrical parameters with different ways of interleaving are studied by the method of numerical simulation. Simple formulas for calculating the electrical parameters of bus packages and finding structural solutions providing a balanced current jaw are obtained.