Study on the audible noise spectrum characteristics of AC 10-bundle conductors at an altitude of 4300 m

At high altitudes, where air pressure is lower, the issue of audible noise (AN) resulting from corona discharge phenomenon in ultra-high voltage (UHV) AC lines becomes obvious increasingly. It affects their line design and conductor selection. However, there is little research on the spectral traits of AN in multi-bundle conductors under high-altitude conditions, which poses difficulties to guide the design of power lines in high-altitude regions. In this study, the noise spectrum characteristics of 10 × LGJ630 and 10 × LGJ720 ten-bundle conductors under rainfall conditions were studied in the high altitude UHV corona cage in Yangbajing, Tibet, and their equivalent A-weighted sound pressure level and 1/3-octave band noise characteristics were obtained. Additionally, the contribution of various frequency bands within the noise spectrum to the overall A-weighted level was analyzed. These results can provide valuable data reference to optimize the construction of power lines in high-altitude regions.