Mathematical Models of Ice Melting Schemes on Lightning Protection Ropes of Overhead Transmission Lines

Abstract

The article is devoted to ice melting (formation prevention) schemes on lightning protection ropes of overhead transmission lines (OHL), in particular, using induced currents. The relevance of ice formation on OHLs, in particular on ropes, and the need for ice melting schemes that implement modern methods are briefly noted. The article reflects the mathematical modeling of ice melting operations on ropes, including use of currents induced by currents in the OHL phase wires. Two frameworks are considered. The first framework employs zero-sequence currents in the wires of the OHL phases, which are taken out of operation. The second framework employs direct sequence currents in the wires of the OHL phases in operation. Formulas for calculating the parameters of the ice melting mode are shown, thus mathematical models for two directions are described. The relevance of credible electrical parameters of the ropes necessary for calculating the parameters of the ice melting mode is noted. Work has been done to determine them in the laboratory conditions, for example, the results of the obtained rope resistivity for two types: S70 and ASC70/72 are shown. The results of identification of the mathematical model of a 110 kV OHL, necessary for calculating the ice melting mode on ropes using currents induced by zero sequence currents in the wires of the OHL phases taken out of operation, are presented. The possibility of identification a mathematical model of a 500 kV OHL during melting (preventing the formation of ice) of ice by ropes using currents induced by direct sequence currents in the phases of the OHL phases is noted, while it is in operation.