Study on Trip Caused by Windage Yaw of 500kV Transmission Line

In order to reduce the trip caused by windage yaw, the windage yaw trips in Huazhong area in June and July, 2004 are analyzed. In thsee cases there is strong wind and heavy rain. There arc trace on tower, hardware and conductors, the reclosing were not successful. Closing were successful after strong wind. The main reason of windage yaw discharge are: 1)The windage yaw is too big due to strong wind; 2) The discharge voltage reduce due to heavy rain; 3) Estimation of scurviness of meteorological condition is not efficient. Adding the heavy punch or jumper line insulator string on dead end tower jumper line, adding heavy punch on insulator string on tangent tower, checking the windage yaw gap combining with meteorological condition and checking the windage yaw foe tree, mountain slope are necessary measure to prevent discharge.