METHOD AND APPARATUS FOR CLOSED-LOOP CONTROL OF THE ELECTRODE SEPARATION IN A VACUUM ARC FURNACE

摘要

The invention relates to a method as well as a device for closed-loop control of the electrode gap in a vacuum arc furnace (10), wherein an electrode gap of a melting electrode from the surface of a melt material is subjected to closed-loop control as a function of a droplet short-circuit rate. For this purpose, a histogram (70) of detected droplet short-circuits (80) is created on the basis of at least one droplet short-circuit criterion (76), the histogram (70) is subdivided into sub-areas (72), a characteristic sub-area (74) of the histogram (70) is selected for closed-loop control purposes, and an electrode gap is subjected to closed-loop control on the basis of the droplet short-circuits (80) which can be associated with the selected sub-area (74).