Technologies and Methods for Corona PD detection and localization: Blackout Test vs. SBUV Camera
Blackout Test – per IEEE1799-2022
A test performed after eliminating all ambient light, specifically on energized electrical equipment, to detect external or surface discharges visible with the human eye (“naked eye”) after at least 20 min of acclimatization.
Solar Blind Ultra-Violet (SBUV) Camera
Solar-blind Ultraviolet (SBUV) cameras are specialized electronic devices that are sensitive exclusively to ultraviolet (UV) light, specifically below approximately 280 nm.
SBUV cameras can detect corona discharges and surface discharges. Such detections can take place even under daylight conditions.
Typically, SBUV cameras are designed as bi-spectral imaging devices, operating at two spectral bands: the solar-blind UV-C band and the visible light band. They produce output images by merging UV and visible light imagery, thereby presenting a comprehensive view of the observed scene.
Comparative Analysis: Blackout vs. SBUV
In our pursuit to better understand and compare the efficacy of the Blackout test and the SBUV camera for PD detection, we adhered to the rigorous methodology described in the IEEE1799 standard.
Needle-Plane Setup: Central to our tests was the needle-plane setup as prescribed by the IEEE1799 standard. This arrangement allowed us to simulate corona discharges, the key phenomenon we aimed to detect.
Human Eye Sensitivity Benchmark: Before introducing any tools, we determined the discharge inception voltage (DIV) using the naked eye in pitch-black conditions. After a 20-minute dark acclimatization period, the participants observed the needle for visible glows, signaling the start of a corona discharge.
Instrument Test: The same test was then conducted using the SBUV camera, but without the need for darkness. The camera’s detection capabilities were compared with human eye sensitivity to evaluate its performance.