3D FEM modeling and analysis of the impact of conductor height and ground conductivity on the peak induced voltages of overhead conductor
摘要
This paper presents 3D modeling for lightning electromagnetic effects to analyze the peak induced voltages on overhead conductors using the finite element method (FEM) and COMSOL Multiphysics software. It mainly focuses on the parameters that affect the peak induced voltage of overhead conductors, such as the height of the conductor from the ground, the conductivity of the ground, and the speed of the source current. Initially, a thorough observation of the return stroke current for lightning strikes to flat ground at different heights along the lightning channel and induced voltage at the center point of the horizontal conductor at distances of 40 m, 60 m, and 100 m from the stroke point has been carried out for model validation. Then the effect of conductor height on the peak induced voltages on overhead conductors, with specific numerical results (e.g., peak induced voltage reaching 75.70 kV at the center point and − 14.87 kV at the terminal point for the 50 m horizontal distance from the stroke point, 4.8 m lower conductor height, and finite ground). It observed that there is a significant impact on peak induced voltages at the center and terminal points at different conductor heights for finite ground conductivity. The findings also show that for finite ground conductivity (0.001 Sm−1), the peak induced voltage at the center point is more than twice the value observed in a perfectly electric conducting ground (5.98 × 107 Sm−1) at a 4.8 m lower conductor height.