Slovenian steel producer SIJ Acroni, which is part of SIJ Group, has tasked Primetals Technologies with the replacement of the existing cycloconverter drive control for the upper and lower motors on the plate mill's roughing stand at the Jesenice production site in Slovenia. Rendering the old drives obsolete, Primetals Technologies installed the VarioVerter cycloconverter solution. The project aims to increase availability and secure the supply of spare parts for the drives. Two main factors played a role when SIJ Acroni chose Primetals Technologies as supplier: a variable replacement concept and competitive investment costs.Primetals Technologies' scope of supply included implementing two VarioVerter cycloconverter controllers, replacing the field control units, commissioning, and a new workstation for easy and remote maintenance and diagnosis of the drive system. The integration into the plate mill's existing basic automation control system was re-established, leaving the interface largely unchanged. To be able to reuse the existing power modules, Primetals Technologies’ tailormade connection cabinet with amplifier cards handles the hardwired interface between the controller and the thyristors. Installation and startup were completed on schedule. After a short startup period, the VarioVerter was adjusted to handle all products and yield strengths without restrictions. Additional technological functions, like ski control, were included in the control of the VarioVerter cycloconverter.SIJ Acroni is Europe's leading producer of stainless quarto plates. The company also specializes in electric and custom steels, which are sold as hot and cold-rolled coils and heavy plates mainly for use in niche products. SIJ Acroni’s plant is located in Jesenice, about 60 kilometers northwest of Ljubljana, the capital city of Slovenia.