Experimental investigation of positive DC corona on conductor bundles

The Corona Phenomenon in Overhead Lines: Critical Overview of Most Common and Reliable Available Models

“…Peek formula (1) does not apply to bundle configurations; research has been conducted to establish a suitable corona inception criterion. Waiving the approximation of uniform radial distribution of the electric field, it is necessary to refer to the maximum value E max attained by the electric field in the bundle proximity, which can be computed through the charge simulation method [45], or approximately for the coaxial configuration [46] and for bundles over a conductive plane [47] through the general formula as follows:…”

“…Data presented by Maruvada et al in [36] show a slight increase in the corona inception field for bundles with respect to single conductors; indeed, in the former case, charged ions and electrons might need an increased electric field to properly start an avalanche, due to the asymmetric radial distribution. Nevertheless, the authors of [46] observed that V inc for bundle configuration may be estimated satisfactorily by the applied voltage, causing E max to be equal to the inception field of any of the subconductors, as if it was alone on the ground.…”

“…The influence of the number of subconductors and bundle radius was assessed in [46]. In particular, while increasing the number of subconductors always results in a reduced maximum electric field, and hence, in a higher inception voltage, the dependence on the bundles radius is more complex.…”