Linear solution of the High-Voltage Transmission Line transient influence problem

The influence of high-voltage transmission lines on cables with a conductive shield has not been widely studied, especially during transients. In this paper, a lumped parameter model of a transmission line is developed in the Laplace domain in addition to a steady-state model to determine the effect of a free decaying component of a current induced into a fiber-optic cable shield. Numerical inverse Laplace transform and linear circuit theory is combined in a solution applicable to models containing mutual induction and electrostatic links between different conductors. A case study is performed for a steel-shielded fiber-optic cable installed on a 110 kV line, which indicates that the induced current is a significant threat to the cable considered. The demonstrated approach can be used for analysis of the influence of a high-voltage line on any elongated conductive object during transients. The proposed method is well suited for parallel computing due to linear nature of equation systems used.