Citation: Baron, B.; Kraszewski, T.; Kusiak, D.; Szczegielniak, T.; Pi ˛ atek, Z. The Synthesis of a Bifilar Short Electric Network for a Submerged Arc Furnace with Delta-Connected Electrodes. Energies 2023, 16, 7386. https://doi.org/10.3390/en16217386 Academic Editors: Ahmed F. Zobaa, Enrique Romero-Cadaval, Tomasz Poplawski and Marek Kurkowski Received: 13 September 2023 Revised: 27 October 2023 Accepted: 30 October 2023 Published: 31 October 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article The Synthesis of a Bifilar Short Electric Network for a Submerged Arc Furnace with Delta-Connected Electrodes Bernard Baron 1 , Tomasz Kraszewski 2 , Dariusz Kusiak 3, * , Tomasz Szczegielniak 3 and Zygmunt Pi ˛ atek 4 1 Department of Drive Automation and Robotics, Faculty of Electrical Engineering, Automatic Control and Informatics, Opole University of Technology, Proszkowska Street 76, 45-272 Opole, Poland; b.baron@po.edu.pl 2 Research and Development Centre Glokor, Gornych Walow 27a, 44-100 Gliwice, Poland; t.kraszewski@glokor.eu 3 Department of Automation, Electrical Engineering and Optoelectronics, Faculty of Electrical Engineering, Czestochowa University of Technology, Armii Krajowej 17, 42-200 Czestochowa, Poland; tomasz.szczegielniak@pcz.pl 4 Faculty of Infrastructure and Environment, Czestochowa University of Technology, 42-200 Cz˛ estochowa, Poland; zygmunt.piatek@interia.pl * Correspondence: dariusz.kusiak@pcz.pl; Tel.: +48-34-325-0801 Abstract: In this paper, a non-linear programming method allowing for the optimization of the structure of high-current circuits that supply resistance-arc furnaces was presented. In the case of resistance-arc furnaces, two types of asymmetries most often occur: structural and operational ones. The structural asymmetry is related to the construction of a bifilar high-current busduct, which leads to the so-called short network. Knowing the parameters of the high-current busduct allows one to determine the operating characteristics of the arc furnace. It is also necessary to know the energy consumed in individual steps of the arc furnace operation. The method proposed in this paper makes it possible to establish guidelines for the modernization of a short network in order to eliminate asymmetry. The presented method was verified on a real object by conducting experimental tests on a furnace with a power of 12 MVA. Experimental tests were first carried out for a furnace with asymmetry, and then, by conducting simulation tests, guidelines for changing the design of the short network were determined. The measurements carried out after the modernization of the short network confirmed that the furnace was in a symmetrical operating condition and confirmed the correctness of the calculation method proposed in this paper. Keywords: submerged arc-resistance furnace; short network; electric arc parameters 1. Introduction In the metallurgical industry, the submerged arc furnace (SAF), also known as the electric resistance furnace (ERF), is mainly used to reduce the use of raw materials such as smelting ores, carbonaceous reducing agents and solvents. It produces ferrosilicon, ferromanganese, ferrochrome, ferrotungsten, silicomanganese alloy and other ferroalloys. The SAF is an electric furnace with huge power consumption, even over 40 MVA, and the maximum current can reach tens of thousands of amperes [1–7]. The short network of the SAF is the high current line from the secondary side of the furnace transformer to the electrodes. Its design should ensure the lowest possible power losses as well as the possibly even distribution of phase power (low power asymmetry) delivered to the furnace. The so-called dead-phase and live-phase phenomena appear in practice [6,8]. Therefore, the high-current busduct should be of low resistance and reactance, and the resistances and inductances of its individual phases should be the same. In order to ensure the smallest possible asymmetry of the phase powers in the zones near the electrodes, the electrodes are placed symmetrically along the circumference of the circle, forming an equilateral triangle. Thus, the distances of individual electrodes from the Energies 2023, 16, 7386. https://doi.org/10.3390/en16217386 https://www.mdpi.com/journal/energies