title: Research on High Sensitive D-Shaped FBG Hydrogen Sensors in Power Transformer Oil.
abstract: Dissolved hydrogen is a symbol gas decomposed by power transformer oil for electrical faults such as overheat or partial discharges. A novel D-shaped fiber Bragg grating (D-FBG) sensor is herein proposed and was fabricated with magnetron sputtering to measure the dissolved hydrogen concentration in power transformer oil in this paper. Different from the RI (refractive index)-based effect, D-FBG in this case is sensitive to curvature caused by stress from sensing coating, leading to Bragg wavelength shifts accordingly. The relationship between the D-FBG wavelength shift and dissolved hydrogen concentration in oil was measured experimentally in the laboratory. The detected sensitivity could be as high as 1.96 μL/L at every 1-pm wavelength shift. The results proved that a simple, polished FBG-based hydrogen sensor provides a linear measuring characteristic in the range of low hydrogen concentrations in transformer oil. Moreover, the stable hydrogen sensing performance was investigated by X-ray diffraction analysis.
authors: Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou 510080, China. csgluoyt@163.com.
authors: Ying-Ting
authors: YT
authors: Luo
authors: Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou 510080, China. tinna2008@163.com.
authors: Hong-Bin
authors: HB
authors: Wang
authors: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China. ncepumgm@gmail.com.
authors: Guo-Ming
authors: GM
authors: Ma
authors: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China. ht_song92@163.com.
authors: Hong-Tu
authors: HT
authors: Song
authors: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China. lcr@ncepu.edu.cn.
authors: Chengrong
authors: C
authors: Li
authors: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China. jiangjun0628@163.com.
authors: Jun
authors: J
authors: Jiang
keywords: FBG; curvature; dissolved hydrogen concentration; power transformer oil; sensitivity