电路引用A guide for the measurement of audible noise from transmission lines.pdfVIP

A GUIDE FOR THE MEASUREMENT OF AUDIBLE NOISE FROM TRANSMISSION LINES - IEEE Radio Noise Subcommittee Report Audible Noise Task Force* INTRODUCTION PERPENDICULAR (90@) The trend toward extra-high-voltage (EHV)has focused attention ii GRAZING (00) on acceptable audible noise levels due to corona. The Radio Noise Subcommittee whose members are intimately concerned with the audible noise problem, has consolidated the results of research and experience to present this guide on the measurement of audible noise from transmission lines. im 0 Transmission line audible noise is mostly a foul weather phenomenon. The highest levels are usually obtained in heavy rain. However, audible noise created during fog or drizzling rain conditions could be a more serious problem because of low ambient noise levels. La~ ~~ aK44 II M- Transmission line audible noise has two characteristic components of noise, namely: (1) broadband white noise audibly resembling a frying 10 or hissing sound and (2) the pure tone components which are harmonics of the fundamental 60 Hz frequency. The pure tones are superimposed over the broadband noise. The most noticeable tone is the 120 Hz hum. Because of the present limitations in knowledge of the 20 ,50 100 500F 000 5000 10000 corona-noise phenomena, line design for acceptable audible noise