Discharge corona UV detection in AC power systems method and apparatus

A corona camera for detecting AC power system high voltage discharge corona, said corona camera comprises:

• an optical system configured to receive UV and visible light from said discharge corona;
• an optical filter configured to remove a portion of said UV and visible light leaving filtered light, said filtered light composed of corona light and ambient light;
• an image processor, said image processor configured to provide a corona shutter during one or more said discharge corona periods and an ambient shutter between one or more said discharge corona periods;
• an image sensor, said image sensor configured to capture a corona-plus-ambient image when triggered by said corona shutter and an ambient image when triggered by said ambient shutter;
• an image subtractor configured to generate a corona-only image by subtracting said ambient image from said corona-plus-ambient image;
• a corona integrator configured to generate a corona frame by integrating one or more said corona-only image;
• an ambient integrator configured to generate an ambient frame by integrating one or more said ambient image;
• a pixel selector configured to produce a display image by replacing said ambient frame pixels with said corona frame pixels;
• and
• a display configured to display said display image.

An automated corona survey system for detecting AC power system high voltage discharge corona, said corona survey system comprises:

• a UV survey camera, said UV survey camera configured to detect ambient light and said discharge corona;
• a weatherproof enclosure, said enclosure configured to hold said UV survey camera and a camera processor;
• a pan-and-tilt unit, said pan-and-tilt unit configured to be mounted on a rigid structure and point said enclosure in any direction;
• an AC power cable, said AC power cable configured to power said UV survey camera, said pan-and-tilt unit, and provide a phase reference to said camera processor;
• a computer at a central location, said computer configured to control said UV survey camera, said camera processor, and said pan-and-tilt unit;
• a communications link, said communications link configured for said UV survey camera and said camera processor to communicate with said computer;
• and
• a computer software program, said program configured to send pan-and-tilt settings to said pan-and-tilt unit, send focus settings to said UV survey camera, automatically detect corona presence, and display corona image, ambient image, and said pan-and-tilt position of any detected corona to operator.