Redesign of a spherical corona shield for UHV substation connectors

When dealing with extra- and ultra-high voltage transmission systems special considerations must be taken into account to minimize corona activity. To minimize its harmful effects often corona shields are required. Depending on the device to protect, corona shields may have different geometries; the most usual are corona caps, toroids and spheres. This work analyzes by means three-dimensional finite elements method simulations the behavior of two spherical shields, i.e. a continuous flat sphere (or standard sphere) and a tubes sphere. Results presented here show that the bar shells allows reducing greatly the weight and ventilates better than the standard solution while ensuring an adequate shielding effect.