Estimation of electric field distribution of Hermstein’s glow corona discharge by spectral image processing

Abstract

We present a spectral image processing method for estimating the distribution of the reduced electric field E/N for Hermstein’s glow corona discharge. This method analyzes spectral images of the discharge taken by an intensified charge-coupled device camera with ultra-narrow bandpass filters at the pixel level. The method requires a shorter measurement time than optical emission spectrometry and can reveal finer details of the spatial distribution. Experiments showed that E/N of discharge at the tip of the electrode locally increases with an increase in the applied voltage. In particular, E/N at the tip of the electrode reaches a high value just before breakdown. Based on the maximum acquired values, breakdown of discharge is estimated to occur when E/N ≥ 270 × 10−21–340 × 10−21 V m2. This study is expected to contribute to monitoring the discharge state of electrical equipment to prevent breakdown and ensure safety.