日本のロケット誘雷実験:平成10年度学術研究賞受賞記念報告

Abstract

本文は「ロケット誘雷放電の解明と電力設備の雷害防止技術に関する研究」の題目による日本大気電気学会の1998年度学術研究賞の受賞記念報告である。日本では1977年より誘雷実験が開始されたが、夏期雷では雷の誘発には至らなかった。冬期雷については、1977年より石川県河北潟干拓地で誘雷に成功し、(1)自動車、柱上変圧器、配電用アレスタ、架空地線電線への雷撃試験、(2)配電線の誘導電圧測定、(3)模擬人体への雷撃実験、(4)放送機材の耐雷特性改善などの研究を行った。1987年からは石川県奥獅子吼山山頂の試験用送電線鉄塔においてロケット誘雷実験を行い、鉄塔各部での電流測定、周囲の土中での電流分布測定、送電線用のZnO避雷器の実規模雷での試験、雷鳴観測による雷放電路の再現において成果を得た。電荷の累積頻度分布、放電の様相、および誘雷電流波形の解析(正極性および負極性リーダの電流波形解析)について述べた。

This paper is an award report of the 1998FY academic research prize of Society of Atmospheric Electricity of Japan on the subject of 'Elucidation of rocket triggered lightning discharge and the research on lightning damage prevention techniques for electric power facilities.' Triggered lightning experiments were started from 1977 in Japan, but lightning was not triggered in summer. However, lightning was triggered in the winter successfully at the Kahokugata reclaimed land in Ishikawa Prefecture. Since that, the following experiments were conducted: (1) experiments on the lightning to automobiles, pole transformers, arresters for distribution and overhead earth wire; (2) induced voltage measurement in distribution line; (3) experiments on the lightning to simulated human body; and (4) improvement of lightning protection for broadcasting materials. Rocket triggered lightning experiments were carried out since 1987 at the test transmission tower constructed on the top of Okushishiku mountain in Ishikawa Prefecture. The effective results were obtained in the current measurements at several parts of the steel tower, current distribution measurement in the underground in the vicinity of the tower base, full scale lightning tests of ZnO arrester for transmission line and reproduction of lightning channel by thunder observation. In addition, the charge accumulated frequency distribution, the discharge pattern, and the analysis of triggered lightning current waveforms (current waveform analysis of positive and negative leaders) were described.