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.