Simulation of corona space charge generated from the ±800kV UHVDC overhead transmission line in a thunderstorm

Abstract

Field experience indicates that over 90% lightning shielding flashover events occurred on the positive pole of a bipolar UHVDC transmission line. This polarity effect might be related to the corona space charge generated from the HVDC transmission line. The effect of corona space charge has not been taken into account in the existing electro-geometric model (EGM) and leader progression model (LPM) yet. A two dimensional numerical model was presented to simulate the corona space charge development from a ±800kV UHVDC overhead transmission line under the thunderstorm field in this paper. The validity of the model was verified by comparing with FVM. Corona discharge current and space charge distribution of the typical ± 800kV UHVDC transmission line under operating voltage and thunderstorm field were presented, which could lay a foundation for the further study on the influence of the space charge layer on the lightning attachment to UHVDC overhead transmission lines.