Design of the Improved EAF's Electric Circuit Mathematical Model for Application in Digital Twin

the article considers the structure of the indirect control loop of total conductivity in the electric mode control system of electric arc furnaces HIREG (Danieli, Italy). For the furnaces, where this system is operated, the overestimated value problem of standard deviations of currents and power at electric arcs, which leads to a suboptimal mode of operation and increased operating costs, is outlined. As a solution to this problem, it is proposed to use the digital twin concept to adapt the control loop setting to the current conditions of charge melting. The main idea of the proposed solution is that using a digital analogue of the electric furnace circuit with the HIREG control system, an iterative search for the most optimal regulator parameters is carried out, provided that its suboptimal operation is detected in accordance with a set of predetermined criteria. The research results are realised on the basis of one of the domestic furnaces. The technical effect was achieved in the reduction form of standard signals deviations of currents and power of electric arcs, which in turn provided value reduction of the operation under current time and specific power consumption.