Flashover Model of Polluted Medium Voltage AC Indoor Insulators Around Electric Arc Nickle Furnace Roof

This paper discusses a mathematical model of insulators on the roof beam of a medium-voltage furnace electrical network that is contaminated under critical conditions. It addresses a dynamic arc model of contaminated insulators, referring to the formulation of the Obenaus model concerning discharge propagation. Experiments were conducted using sample of G7 glass-silicone laminated, and Mica insulators that are installed on structural beams and the electrical network of a pyrometallurgical furnace with the aim of measuring flashover voltage and determining the arc parameters (n and N) of the polluted insulator. Several parameters in the dynamic model, including arc current, arc length, and arc resistance, are computed using MATLAB, incorporating the use of optimization algorithms to estimate n and N with several level of pollution and insulator types. The actual results of the proposed model are then compared with experimental findings, including comparisons with several previous studies, despite differences in voltage levels and variations in pollution layer resistances. The experimental and simulation findings indicate the medium voltage insulator's expected performance under different operating conditions per the IEC 60439 standard. The results show the feasibility of assessment of polluted material severity on different type insulators and flashover prediction, using the proposed model.