Characteristics of Corona Discharge in an Icicle/Iced-plate Electrode System under Negative DC Voltage

This paper presents the results of a series of experiments on the corona discharges occurring at icicle tips under negative DC voltage, using an icicle-iced-plate electrode system. The corona discharge development processes and the responding discharge current pulses were recorded. The influences of the gap distance, the icicle surface state and the freezing water conductivity on the corona inception voltage (V
_inc
) and volume as well as on the current pulse waveforms were investigated. The results were compared with previous experimental results obtained under positive DC voltage. The results will help to advance our knowledge of the initial discharge activities occurring on the ice-covered insulators