GIS disconnecting bus results in very fast transient overvoltage（VFTO）

and vacuum switch switching inductive load produces multiple restriking overvoltage.These fast transient overvoltages can make uneven distribution in the insulation of electric equipments

and make them overstressed.In this paper

an enhanced skin effect method is proposed to suppress the fast transient overvoltage.A coaxial structure

taking a conductor as the core

high frequency magnetic rings as inner layer

and a resistant tube as outer layer

is adopted to generate the enhanced skin effect.In this coaxial structure

the normal power frequency current takes a way through the central conductor

and the high frequency fast transient overvoltage is forced to the outer resistant layer due to the enhanced skin effect and is damped there.Significant suppression effect of the fast transient overvoltage is achieved in simulation tests.