Influence of water vapor concentration on photoacoustic spectroscopy‐based characteristic gas analysis of transformer faults

• Published in: Microwave and optical technology letters Vol. 66; no. 7
• Main Authors: Mo, Bingyu, Zhou, Shanghu, Han, Menglong, Xie, Pengsheng, Li, Chenxi, Han, Xiao, Qu, Quanlei, Li, Jianwu, Chen, Ke
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc 01.07.2024
• Subjects: Acetylene; Air monitoring; Carbon monoxide; dissolved gas analysis (DGA); Dissolved gases; Fault detection; Gas analysis; photoacoustic (PA); relaxation of gas molecules; Signal detection; spectroscopy (PAS); trace gas detection; Transformers; Water vapor; water vapor concentration
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.34258

The water vapor in the ambient air affects the accuracy of the photoacoustic (PA) dissolved gas analysis system for transformer health monitoring. A laser PA system was evaluated by dry and humidified standard gases to study the influence of water vapor concentration on PA gas detection. Theoretical analysis was conducted on the effect of gas molecule relaxation on PA signal detection. A high‐frequency resonant PA cell and a low‐frequency nonresonant PA cell were used to detect acetylene (C2H2) and carbon monoxide (CO), respectively. The experimental results show that the PA signal of humidified CO is about 12 times higher than PA signal of dry gas for the resonant PA detection system, respectively. In addition, as the frequency is increased from 30 to 980 Hz, the PA signals of humidified and dry CO attenuate by 1.5 and 6.9 times, respectively.