Environmental effect on high voltage AC transmission lines audible noise

A primary corona phenomena that is important for conductor selection is the audible noise (AN) due to this phenomena at higher voltages. This paper presents the main causes of audible noise in some high voltage power system (380 kV and higher) transmission lines. Simulation of different transmission configurations under various weather conditions, that exist in the Eastern part of Saudi Arabia is done in this paper. The simulation is done by the use of the ACDCLINE program of TL Workstation designed by EPRI. The use of mathematical formulas to calculate AN of transmission lines of 345 kV and above is evaluated by a software package written in FORTRAN 77 compiler, the results of both simulated and formulas are compared and verified for some existing data. The influence of rainfall intensity, lateral profiles of audible noise and the effect of bundle subconductor spacing is also discussed. These effects are manipulated in order to decrease the audible noise on certain transmission line configurations. Other methods for the reduction of audible noise are also evaluated