OPTICAL FIBER SENSING OF SF6 DEGRADATION IN HIGH-VOLTAGE SWITCHGEAR

Abstract

Sulphur hexafluoride ( SF 6) is used as an insulator in high-voltage systems. An electrical breakdown dissociates ( SF 6). Therefore, the insulating efficiency is degraded. If the ( SF 6) is not renewed, failure of the system can occur. A monitoring device for ( SF 6) loss is required, and an optical fiber sensor for continuous monitoring of ( SF 6) degradation in high-voltage switchgear has been developed. Dissociation products of the ( SF 6) discharge include HF and atomic F, both of which react readily with silica. This reactivity is utilized in our sensor, where etching of a glass fiber surface modifies the transmission characteristics of the fiber.