Corona performances of a sagged small-scale HVDC line

Current density distributions below a laboratory small-scale model of a sagged HVDC line in a corona have been detected. The databases given for different catenary shapes show strong departures from those relevant to the horizontal wire-plane assembly. The main qualitative discrepancies consist of the presence of substantial irregularities affecting the profiles transversally and longitudinally to the line and in a dramatic decrease towards the catenary ends. Such features hold even for moderate sags, irrespective of the introduction of grounded supports. On the other hand, the usual quadratic I–V law, governing the average per-unit current, is also applicable to sagged conductors, even though the magnitude of such a loss parameter results significantly affected by the sag, according to an unspecified law