Verification of Occurrence of Overvoltage in Low-Voltage Circuits due to Lightning Strikes on Wireless Communication Towers in Electric Supply Stations and Measures to Suppress

Abstract

In order to investigate measures to prevent damage to low-voltage circuits caused by direct lightning strikes to communication towers in electric supply stations, an impulse test was conducted and evaluated the effect of improving the grounding structure on reducing surge voltage in low-voltage circuits. The measures to improve the grounding structure include: (1) Reduction of the current itself flowing to the building ground wire. (2) Suppress the potential difference that occurs between the ground of the transformer for the power supply in the station and the building ground. (3) Eliminate the mixing of low-voltage cables with metal shielding (grounding at both ends of the shielding layer) and low-voltage cables without metal shielding. As a result of the experimental verification, we have confirmed that each of the three methods is effective in reducing the surge voltage generated in low-voltage circuits.