Breakdown and optical emission characteristics of point-to-point electrodes subject to pulsed 20kHz applied field in sub-atmospheric pressure N2-He gas mixtures

In power systems, corona and partial discharges are among the causes of failure under high electric fields and stresses. The breakdown initiation voltage is a function of several design and environmental parameters: operation pressure, background gas type, electrode gap and its geometry, and the applied voltage level and frequency. In this paper, the breakdown characteristics of a point-to-point electrode geometry in sub-atmospheric pressure nitrogen and helium gas mixture are presented. A 20 kHz unipolar pulsed signal is applied to electrodes and the breakdown voltage, current, and optical emission waveforms are collated. In addition, breakdown voltage versus pressure data is presented and time resolved optical emission spectra and fast frame image data are recorded. The spectroscopic data and image data are compared, and a time evolution of the breakdown events is presented.