DC corona discharge of metal filament particle within parallel plate electrodes

When a metal particle accidentally exists within gas-insulated switchgear (GIS), it might lead to serious damage of a power transmission system. The authors have investigated and reported on the motion of a metal filament particle within parallel plate electrodes. When a metal particle on the electrode gained some charge by induction, it shows several different patterns of motion; such as simple standing, precession motion, jumping up-and-down, and so forth. Each case of such motion depended upon corona discharge from the particle itself. When the corona current from a fixed particle on the electrode was measured, either positive or negative corona takes place. The measured current showed different patterns of current depending on the polarity. The current characteristics also depends on the size of particle. Furthermore, when a particle is very short and the case of positive corona, strange characteristics of current were observed.