Development of anti-galloping device for UHV transmission line

1000 kV UHV transmission lines in Japan pass through high mountainous areas, and are exposed to severe weather condition such as strong wind and heavy icing on conductors. In recent years, galloping phenomenon, which is one of the abnormal and lasting conductor oscillation caused by conductor icing and heavy wind, was observed in some UHV transmission lines. The authors, therefore, have developed anti-galloping devices applicable to UHV transmission lines, and conducted field tests using Takaishiyama test line to verify their effectiveness. The devices developed were based on eccentric weights plus rotation-free spacer type, which has successful past records for deterring galloping in many lines of multi-bundle conductors in service, and loose spacer type. As a result, it was verified that the developed anti-galloping devices could reduce conductor tension change considerably compared to the case without any countermeasure.