Moisture Content Determination of Transformer Oil by Using Terahertz Time-Domain Spectroscopy
JIANG Qiang1，WANG Yue2*，WEN Zhe3，WANG Ji-hua4
1. Chengdu Product Quality Supervision & Inspection Institute, Chengdu 610000, China
2. State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080，China
3. Chengdu Institute of Product Quality Inspection Co., Ltd., Chengdu 610000, China
4. China Resources Power(HaiFeng)Co., Ltd., Shanwei 516468, China
Abstract：The maintenance of the transformer is more and more important and the analysis of moisture content in transformer oil has become a very important part of transformer maintenance. Water is known as a strong absorber for THz radiation due to its distinctive intermolecular vibration in this frequency range. In the present work, we analyzed transformer oils regarding their water content by THz spectroscopy. Based on THz time-domain spectroscopy, information about the absorption coefficient and the refractive index of the oil samples is provided. By comparing the results with relevant theories we demonstrate that both the absorption coefficient and the refractive index are linearly related to the concentration of water in the oil solutions.
Key words：Terahertz time-domain spectroscopy；Transformer oil；Moisture content Test
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