Corona-Loss Characteristics of EHV Transmission Lines Based on Project EHV Research

Since 1960 the corona-loss characteristics of a variety of extra-high-voltage (EHV) transmission-line configurations have been under study at Project EHV [1], [2]. This paper presents results from the analysis of corona losses measured under all weather conditions experienced during 2¿years of observation of single or bundled conductors at 500 or 700 kV. In addition, corona characteristics are presented for switching-surge transients and severe steady-state overvoltages. The purpose of this paper is: 1) to summarize some of the statistical aspects of fair-and foul-weather corona-loss observations for the configurations studied, and 2) in terms of electrical and meteorological parameters, to describe an equation for corona loss on EHV lines that is in a form directly applicable by transmission engineers to EHV-line design.