Influence Analysis of Mutual Coupling Effects between a High-Voltage Transmission Line and a Fibre-optic Cable with a Conductive Support Element

Applications of fibre-optic cables with conductive support elements for installations on high-voltage line towers are not as common as all-dielectric cable designs. Therefore, the influence of high-voltage lines on such cables has not been studied widely. In this paper, a lumped parameter model in phase coordinates is developed to determine the current and voltage of a conductive element of a fibre-optic cable section installed on a high-voltage line. Methods required to determine the parameters of the mutual induction and electrostatic links for this model are provided. A case study is performed for a figure-8 cable application on a 330 kV line, which indicates that the induced voltage to earth is a significant threat to the cable if the conductive element is insulated from the earth. The demonstrated approach can be used for analysing the influence of a high-voltage line on any elongated conductive object.