This paper substantiates why it is necessary to limit the dynamic loads in stand shafts when closing angular gaps. The paper is a feasibility study of a concept developed specifically to limit each of the factors that affect amplitude of the dynamic torque; limitations applied are determined on a case-by-case basis. The research team studied the components of elastic torque in a dual-mass electromechanical system of Mill 5000 caused by vibrations arising from the elasticity of transmission as well as from the vibrations caused by elastic collision itself. It is shown that the lowest possible pre-acceleration is necessary for decreasing the dynamic coefficient at a near-nominal load torque. A principle of limiting dynamic loads when closing an angular gap is proposed, which implies collecting tachograms of an electric drive subjected to positive or negative acceleration before and after the fed metal is captured. The research team has developed drive control principles to implement this approach. The recommendation is to upgrade the electric drives of the reversing stand in Mill 5000.

This article considers the development of digital twins (DT) for the mechatronic facilities of the coiling machine group in a wide-strip hot rolling mill. The analysis of Russian and foreign sources confirmed that a lot of attention is paid to the economy digitalization. All of the leading metal plant equipment and electrical engineering system manufacturers are working on creating DTs. The analysis of the literature showed that the authors lack a uniform understanding of the conceptual directions in the creation of DTs and there are many definitions of this term. Therefore, the first part of the article deals with the analysis of the digital twin concepts according to their application at industrial companies. The authors substantiate the feasibility of the DT de-velopment for the electromechanical and mechatronic systems of the most complex metal production components, i.e., rolling mills. This initiative development is relevant due to the reconstruction of the 2500 wide-strip hot rolling mill at Magnitogorsk Iron and Steel Works PJSC (MMK PJSC) that involves the installation of unique equipment. Due to this, the development of DTs to implement the virtual commissioning of the equipment becomes a priority. The virtual adjustment of automation and process control systems is also required. This problem can be solved through the example of three coiling machines, each of which has electric and hydraulic auxiliary equipment. These coiling machines are used for rolling the heavy hot-rolled bar and they feature a unique design. Therefore, the development of DTs for mechatronic facilities is a novel scientific problem. The authors propose the methods for the development of DTs used in the virtual commissioning of process control systems. They present the structure of the coiling section automation system and the structure of the DT imple-mented on the basis of programmable logic controllers (PLC). The authors provide the specifications for the Siemens PLCs installed at each of the coiling machines and the coiling machine master controller. To develop the control systems for electric and hydraulic drives, it is recommended to use the Matlab Simulink software package. The authors provide temporal dependencies obtained using DTs and other similar oscillograph charts produced during the operation of the coiling machine that can help model the operation of the mechanisms in question. The results of their comparison show that the processes correspond to each other. Thus, the use of the developed DT to adjust the electrotechnical systems of rolling mills is reasoned. The accepted concept of making digital twins for the electrotechnical systems of rolling mill components is relevant and technically feasible

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Transients in electromechanical systems need to be modeled adequately if the existing electric drive control algorithms are to be improved, or new ones are to be developed. This fully applies to the electric drives of roll-ing mill stands. When studying such drives, one often needs to find a tradeoff between the complexity of Park-Gorev equation-based mathematical description of processes in variable frequency drives, and the capabilities of simpler models that adequately describe the processes relevant for each specific case. The latter include the known dual-mass model of the electromechanical system of a rolling mill stand featuring a flexible shaft and gaps in transmissions. Research presented herein covers the parameters of this model, which need to be ob-tained experimentally. The most accurate way to find the model parameters is to derive them from the oscillo-grams sampled on the object when running in typical transient. This particular paper addresses the electrome-chanical system of the horizontal stand in Plate Mill 5000 deployed at Magnitogorsk Iron and Steel Works (MMK PJSC). The paper substantiates the methodology behind parametrizing the system and shows how to cal-culate the moments of inertia of rotating masses from oscillograms of unloaded drive acceleration. To showcase the method, the paper presents finding the stiffness factor of an elastic coupling from the transients recorded when halting the electric drive. Focus is made on finding the time constants of the internal torque control cir-cuit as approximated by first-order or second-order filters. By comparing the simulation output against the os-cillograms sampled on the mill itself, the model was proven to adequately compute the parameters of the object. The paper concludes with recommendations on how the developed methods could be used to find the parame-ters of a dual-mass system when modeling the electric drives in rolling mills. The conclusions outline possible further research.

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