Image Analysis: A Tool for Optical-Emission Characterization of Partial-Vacuum Breakdown

Power devices and systems operating in partial vacuum are susceptible to partial discharges, corona, or volume discharges. In this paper, we present an image-analysis technique and its results for optical-emission characterization of a breakdown initiation. The example set for demonstration is breakdown events under a 20-kHz unipolar sinusoidal applied field for a point-to-point electrode geometry at partial vacuum in helium. The voltage and current waveforms along with the light-emission data are collected. The results of the image-analysis technique used to obtain the R/G/B emission characteristics of the breakdown events as a function of time, location, and pressure are presented. The images obtained by a standard 30-ft/s video camera are used for analysis to characterize the progress of the breakdown.