Automatic control of arc steel-making furnace power mode based on active power uniformity

The paper considers the issues of improving performance of ultra-high power arc steel-making furnaces. It highlights special aspects of 180 t furnace (DSP-180) operation modes and provides a curve of varying active power consumption. It offers a flowchart and operation principle of the ArCOS two-channel power mode control system as well. Its drawbacks mentioned in this paper include the need for regulation of the secondary circuit impedance and a slow system response. Process stages and standard diagrams of controlled parameter changeover are under consideration. A three-channel system may efficiently regulate the process power mode of arch steel-making furnace with automated control of transformer voltage, reactor inductance and secondary circuit impedance. The authors set a challenge to implement this principle at operated electric equipment with the aid of the ArCOS algorithms. Analysis of active power curves helped determining reactor inductances for a certain arch current values at the specified secondary voltage. The authors also propose the formula to calculate the best ratios of transformer secondary voltage and reactor inductance. It enabled determining numbers of transformer and reactor stages that maintain the specified active power consumption. These ratios are recommended for development of the best DSP-180's power modes. Development of power mode control of arc steel-making furnaces with non-contact regulation of transformer voltage and reactor inductance is a promising trend.