ABSTRACT The low pressure in high‐altitude areas exacerbates the issue of audible noise (AN) caused by intense corona discharge on the conductor surface. This problem is a critical factor in the structural design and conductor selection for extra‐high‐voltage and ultrahigh‐voltage (UHV) AC transmission lines. The study of spectrum characteristics is vital for understanding the intrinsic properties of AN. However, there is a lack of studies on the AN spectrum properties of practical bundled conductors at high altitudes, which makes it difficult to accurately guide power line construction in high‐altitude regions. The high‐altitude UHV corona cage in Yangbajing, Tibet, was used in this work to investigate the noise spectrum properties of three conductor types: 6 × LGJ500, 8 × LGJ630 and 10 × LGJ630. The conductors' 1/3‐octave frequency noise characteristics and AN equivalent A‐weighted levels under different electric field strengths under heavy rain were measured. Then, the correlation between the 8‐kHz characteristic frequency level and the AN A‐weighted sound level in high‐altitude regions was investigated. Finally, the A‐weighted acoustic power levels of AN at three altitudes of Wuhan, Xining and Yangbajing were compared and analysed. The results of this study can provide certain guidance for power companies' high‐altitude power line designs.
He et al. (Fri,) studied this question.