Uncertainty of $L_{\textrm{DEN}}$ calculation for corona noise from Ultra High Voltage power lines using reference methods

Abstract

Accordingly to the regulations contained in the European Noise Directive (END) and also in some legal acts being currently under legislative process in Poland, in the nearest future the $L_{\textrm{DEN}}$ and $L_{\textrm{N}}$ levels will be used as the basis for evaluation of corona noise from UHV power lines. The paper presents an example of combined uncertainty evaluation for estimation of long-term level ($L_{\textrm{A, LT}}$) and $L_{\textrm{DEN}}$ level for corona noise from UHV overhead power lines. Some specific features of that noise – large time variation of its level and spectral structure, dependent on the atmospheric conditions, and on the other hand often small distance from the background noise – are the reason that the evaluation of its estimation uncertainty is more difficult then for some other, better “determined” noise sources. The partial uncertainties related to the measurement system and prediction method according to the reference methods for industry noise were dealt with. The effect of the environment on the system and the measured quantity have been distinguished and quantitatively determined.