Advanced Metal Oxide Surge Arrester For Gas Insulated Switchgear (GIS)

SF6 gas has outstanding dielectric strength and heat transfer property. This suggests that zinc oxide (ZnO) elements whose value of E in E-J characteristic is higher than the value of the elements used in a porcelain type arrester is suitable to metal enclosed metal oxide surge arresters (MOA) for gas insulated switchgears (GIS). Several kinds of newly developed ZnO elements with the high values of E and their practical performances are discussed in this paper. The application of these elements realizes more compact and simpler arresters which have outstanding protection performance for GIS.