Generalized Model for Calculating Induced Voltage on the Sheath in Steady-State for Single-Circuit Underground Transmission Lines

This paper presents a generalized formula for the calculation of induced voltages within underground transmission cable sheaths. This formula considers the internal and earth-return impedance based on the comprehensive electro-magnetic field solutions proposed by Xue et al. 2018. In this study, we compare and discuss the results obtained using mathematical formulations recommended by IEEE 575 and CIGRE 283 standards, all analyzed under steady-state conditions. The study mainly focuses on the triangular and flat formations of three-phase transmission lines, along with two specialized cross-bonding techniques (continuous and sectionalized) designed to reduce voltage along the cable sheath. The results indicate that, in the case of the triangular formation, the generalized model yields induced voltage values that are, on average, 5.8 V higher, representing an additional 6.5%. Conversely, for the flat formation, the generalized model results in induced voltage values of 5.55 V higher, constituting an additional 5%.