DEVELOPMENT OF GALLOPING ENDURANCE DESIGN FOR EXTRA LARGE 6-CONDUCTORBUNDLE SPACERS BY THE EXPERIENCE OF THE PULL SCALE 500KV TEST LINE

Large diameter bundle conductors, which result in lower line inductanc e is one of the most cost effective methods to gain stable power trans fer capability on a long bulk power transmission line. To bring this n ew type of conductor into practice, since galloping is a major cause o f damage to transmission lines in certain regions of Japan, it is esse ntial to grasp the dynamic mechanical loads during the phenomena. New methods for designing several kinds of hardware involved in the new 50 0kV bulk transmission facilities utilizing extra large 6 conductor bun dles were developed using three years of field experience on a full sc ale 500kV testing line. The 769m test line supported by three full sca le supporting structures were constructed on Mt Sanpo (alt 970m) locat ed 35km from the Japan sea, where frequent galloping phenomenon was ob served. This paper features the methods used in designing the spacers developed from the field studies.