| 摘要 |
<p>PURPOSE:To prevent at least power failure when thunderbolt surge is, infiltrated, by mounting a lightning protection insulator device corresponding to the power line of a lower phase during power transmission by plural lines, and making the voltage phases, of the power line of a lower phase, different each other. CONSTITUTION:Since an overhead earth wire 20 is mounted on the tower top part of an iron tower main body 1, thunderbolt current, infiltrated into the tower top part, is infiltrated into the upstream side of the overhead earth wire 20 from the tower top part and into the iron tower main body 1 from the tower top part. In the case of a large scale lightning stroke, the insulating supporting special insulators 5a, 5b, 6a, and 6b of the upper and middle phases are flushed over by this diversion thunderbolt surge current to be diverted to power lines 8a, 8b, 9a, and 9b, and the remaining thunderbolt surge current and moreover the remainder are diverted to power lines 8c and 9c from lightning prevention insulators 11 and 11 and to the ground respectively. Although respective power lines are temporarily interrupted by a substation etc., power transmission is continued in two-phase power lines 8c and 9c, having different voltage phases, and operation can be quickly resumed by closing the breakers of the respective power lines 8a, 8b, 9a, and 9b in the upper and middle phases.</p> |
