Heat Transfer Characteristics of Gas-Insulated Transmission Lines

This paper reports on an investigation of the heat transfer characteristics of GILs under constant temperatures and under changing temperatures influenced by solar radiation and wind. It was verified that values calculated by our heat transfer formulas coincided well with measured values both for current-induced temperature rise of the conductor and enclosure and for temperature changes caused by solar radiation and wind. In addition, the influence of installation angle on conductor and enclosure temperature rises was investigated, and it was confirmed that the highest local temperature rises of a conductor and an enclosure above ambient temperature generally do not exceed the temperature rises of horizontal installation, although heat spots existed in tests.