High voltage capability electrical coils insulated with materials containing SF6 gas

摘要

A coil is made having a plurality of layers of adjacent metal conductor windings subject to voltage stress, where the windings have insulation therebetween containing a small number of minute disposed throughout its cross-section, where the voids are voids filled with SF6 gas to substitute for air or other gaseous materials in from about 60% to about 95% of the cross-sectional void volume in the insulation, thus incorporating an amount of SF6 gas in the cross-section of the insulation effective to substantially increase corona inception voltages.