Fiber-Enhanced Raman Spectroscopic Monitoring of Fault Characteristic Gases Dissolved in Transformer Oil by Hollow-Core Photonic Crystal Fiber

Abstract

The accurate detection of trace fault characteristic gases dissolved in transformer oil is the key to achieve transformers’ operation status diagnosis. In this paper, we designed and established a detection platform based on fiber enhanced Raman spectroscopy (FERS), which uses a 1 m long hollow-core photonic crystal fiber (HC-PCF) as the sample container, thus simultaneously increasing the effective interaction path length of light-analyte and improving the photon collection efficiency. The simultaneous Raman spectroscopy detection of 7 kinds of mixed fault characteristic gases, such as H 2 , CO, CO 2 , CH 4 , C 2 H 2 , C 2 H 4 and C 2 H 6 , was achieved, and the characteristic Raman shift lines were respectively identified as 4156, 2143, 1388, 2914, 1977, 1344, 2954 cm-1. Taken H 2 as an example, the measured Raman signals shows excellent relationship with the sample concentration. The experiment results prove that FERS provides a very promising method for highly selective and sensitive gas analysis in transformers’ operation status diagnosis.