Audible noise of transmission lines caused by the corona effect: Analysis, modelling, prediction

The paper presents the results of investigations of audible noise of high voltage transmission lines of alternating current (a.c. UHV) caused by the corona effect. The investigation results concern the 400 kV lines in two basic layouts existing in Poland: single horizontal and double vertical. Environmental investigations in real conditions were executed in a whole year cycle with the short-term method. Apart from the results of the environmental investigations the paper contains also the laboratory investigation results. The influence of constructional design and environmental parameters on the sound level distribution along a span was analysed. The influence of the conductor surface stare and weather conditions on the level and shape of the emitted audible noise spectrum was particularly taken into account. The evaluation of the influence of the line audible noise on the acoustic climate of the environment was carried out. The analysis of possibilities of the application of well known computational procedures to the prediction of the line audible noise caused by the corona effect in Polish conditions was executed and an original form of a line acoustic model with the audible noise prediction possibility as a function of rainfall was presented. (C) 1996 Elsevier Science Ltd.