Corona and Micro-gap Discharge occurring at a Wire Particle in a Precessional Motion under a DC Electric Field

Abstract

A free wire particle located in the electric field between parallel plate electrodes manifests several motions; standing, precession on the electrode, crossing and breakdown via the particle. During the stable standing or precessional motion, corona discharge involves inevitably. To clarify the influence of discharge phenomenon on the behavior of the wire particle, the corona discharge characteristic of the particle in the precession was investigated experimentally in a dc electric field formed with parallel plate electrodes where positive voltage was applied to the upper electrode. The waveforms of corona discharge current flowing through a 6mm-wire particle were measured under the two conditions when a free wire was in precession on the lower electrode and when a wire was fixed between the electrodes vertically with a spacing less than 1mm between the lower electrode and the bottom of the particle. From the comparison of the waveform of corona discharge occurring at the particle in precession with that of the fixed particle, it was found that both micro-gap discharge and negative corona occurred simultaneously only when the particle was in the precession with a relatively small elevation angle. The particle lifted up when the magnitude of corona discharge current was decreased bellow around 15 μA.