TRANSMISSION-LINE CORONA LOSSES UNDER HOAR FROST CONDITIONS

Transmission line corona losses under hear frost conditions were studi ed in the climate room of the high voltage laboratory of Tampere Unive rsity of Technology, The measurements were performed using a coaxial m easurement arrangement with different bundle and conductor types, The effects of conductor and bundle type, temperature, applied voltage and boar frost thickness on corona losses were investigated. A two-conduc tor bundle had corona losses about 2.5 ... 5 times higher than a three -conductor bundle, Relatively thin hear frosts were used in the tests. Even the thinnest boar frost resulted in remarkable corona losses and the losses were very sensitive to changes in the boar frost thickness . The ambient temperature had a strong influence on the measured losse s.