LIGHTNING PROTECTION STRUCTURE OF HIGH-STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a lightning protection structure for a high-structure such as a windmill tower etc., which is constructed at a place where low ground impedance cannot be ensured like the mountain area, capable of protecting a shielding layer of a power cable used in a ring main unit from being subjected to a transient overvoltage even when receiving a lightning strike.;SOLUTION: The self inductances L₁, L₂ of the ground wires 7, 10 are reduced by making one or both of the inner grounding wires 10 plural in a tower connecting the rising ground wire 7 or the copper inner bar 8 in the tower and the copper bar 9 in the ring main unit, which is connected to the bonding hardware 4 and is embedded in the tower with its upper end portion arranged in the tower. At the time of lightning strike, the transient overvoltage generated in the shielding layer due to the lightning current is reduced, and burnout of the shielding layer is prevented.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT