Electrode control circuit for electric arc furnaces - manipulates electrode positions independently to control quality cost function and to minimize unbalanced phase loads

摘要

The network is for controlling the operation of electric arc furnaces by manipulating the positions of each electrode independently and by imposing certain restrictions on the voltage and current supplies. In furnaces of this kind, imbalance between the three phases leads to very unequal wear. The network presented here controls the position of each electrode to equalize the wear on the electrodes according to a cost function which depends on the voltage and current supplied to the electrodes. This is achieved by a series of control loops, one inside another applied individually to each phase. The innermost loop is an electrode velocity control using a velocity feedback (5) and an amplifier and drive arrangement (3, 4). The loop is nested within a phase voltage control loop for which the set point is found by multiplying a set point phase resistance and the measured phase current in a multiplier (1).