Five years´ experience with ultrahigh-speed reclosing of high-voltage transmission lines

The data covering five years´ operating experience with 33 ultrahigh-speed reclosing breaker installations mainly on a large interconnected and integrated high-tension system are presented and analyzed, and conclusions based on this experience are drawn. Out of 71 cases of flashover cited, 65 reclosures were successful and 6 cases of reclosure resulted in restrikes, a record of 91.5 per cent successful reclosures. The conclusions drawn are that not only is actual performance better than appeared possible when the development was first made but that further improvements are possible by further reducing breaker time.