A fluorescent plastic optical fiber sensor for the detection of corona discharges in high voltage electrical equipment

The reliability of electrical equipment in high voltage systems can be affected by certain defaults (metallic particles, roughness, etc.) inside the device enclosure. These anomalies may cause a local glow discharge which propagates progressively inside the insulator and which can lead to electrical breakdown. To avoid this end result, corona discharges have to be detected with a system which satisfies some requirements. Actual methods are not well adapted to industrial constraints. An optoelectronic setup, consisting of a fluorescent plastic optical fiber as a light sensor, connected to a simple, low-cost amplifier, is proposed. Measurements were first carried out in air to demonstrate the feasibility of this detection method, then air was replaced by SF6. Results lead to the delineation of a sensor made of the fluorescent fiber and the associated amplifier.