Laboratory Testing of a Sensor for Hydrogen Dissolved in Transformer Oil

Trace Detection of Dissolved Hydrogen Gas in Oil Using a Palladium Nanowire Array

“…For this reason, response and recovery were virtually unchanged across the temperate range explored here, except for some acceleration of the response at higher temperatures that can be attributed mainly to more rapid diffusive contributions to mixing. A more sophisticated oil flow system would be required to measure the sensor-limited response and recovery, but the rapidity of the response demonstrated in Figure is already sufficient for DGA. − …”

“…The most important technological application for dissolved gas analysis (DGA) is the detection of incipient faults in utility scale oil-filled power transformers. − Failure of a power transformer is known to be preceded by the evolution of hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, and acetylene caused by corona discharges, insulation degradation, and the decomposition of oil at “hot spots”. ,− The identity and concentrations of these dissolved gases enables the type of fault that will occur to be classified. , …”

“…Until recently, DGA has involved the off-line measurement of gases in aliquots of oil using gas chromatography. ,,, This process is time-consuming, expensive, and prone to sampling error caused by temporal and spatial fluctuations in dissolved gases within the enormous oil volume of the transformer. These considerations have motivated the development of oil-immersed gas sensors that are capable of the continuous, real-time monitoring of dissolved gases (see Table ). ,,− A unique set of analytical challenges exists for these sensors. In the case of dissolved H 2 , a limit-of-detection well below 100 ppm is required, the dynamic range of the sensor should extend to at least 1000 ppm, and the sensor should not be damaged by exposure to higher H 2 concentrations .…”