| 摘要 |
A solar blind corona camera designed specifically for use on 60 Hz or 50 Hz AC power distribution equipment is based on the fact that electrical discharge corona only occurs above some voltage threshold level on the positive and negative voltage peaks of the AC power waveform. Between these peaks, when the AC voltage is below the discharge corona voltage threshold, the electrical discharge and resulting corona are extinguished. An image sensor is used to both capture the corona-plus-ambient light image during the corona period and the ambient light image during the non-corona period. The ambient light image is then subtracted from the corona-plus-ambient light image leaving only the corona light image which is annunciated and displayed along with the ambient light image. This process effectively renders the corona camera solar blind so it can be used both at night and during daylight. |
