Audible noise performance of 6-rail conductors on a 765-kV double circuit test line

To satisfy an annual rate load growth of approximately 10% per year, Korea Electric Power Corporation (KEPCO) has been studying the use of double circuit 765-kV transmission lines. Since this would be the first application in the world for such lines, a 765-kV test line was built near the Yellow Sea to gain experience with this higher voltage. A primary corona phenomena that is important for conductor selection is audible noise (AN) due to corona. This paper presents the results of long-term measurements of AN from the 765-kV double circuit test line using a bundle of 6-483.8 mot conductors at Korea Electric Power Research Instituteʹs (KEPItI) 765-kV test station. The analysis of the data shows that the 6-Rail conductor bundle satisfies the AN criterion of 50 dB(A) under rainy weather conditions.