Improved Unitary and Multicomponent Gaseous Insulators

Improved unitary and multicomponent gaseous insulators are systematically designed according to detailed knowledge of fundamental electron-molecule interactions. Knowledge of the electron attachment and electron slowing-down properties of dielectric gases/mixtures as functions of electron energy is shown to be especially significant. On the basis of such knowledge it is possible to improve the gaseous dielectric's breakdown strength by effectively controlling the numbers and energies of the electrons present. Several unitary (e. g. C4F6, c-C4F8, and iso-C4F8) and multicomponent (e. g. C4F6/SF6/N2 and c-C4F8/C4F6/SF6/N2) gaseous systems have been tested and found to have better dc breakdown strength properties than SF6. These findings are reported and discussed.