Research on Hydrogen Gas Sensing Mechanism of Micro and Nano Ionization Sensor

The detection of hydrogen gas (H
2
) is crucial for predicting incipient faults in transformers and ensuring the safe operation of smart grids. Micro-nanotip-based micro-ionization sensors, characterized by fast response speed, easy integration, and resistance to concentration saturation, have the potential to meet the emerging demand for detecting fault feature gases in transformers. By establishing a mixed micro-corona discharge fluid model of N
2
-H
2
as the research object, this study investigates the discharge characteristics of different concentrations of hydrogen gas and simulates the change in sensor electrodes’ sensitivity to hydrogen gas concentration under the same discharge condition. Further analysis reveals a single-value sensitivity law of H
2
concentration based on ion generation rate during different concentrations discharge process from perspectives such as density distribution of positive ions and generation rules of positive ions. It is found that N
2
metastable is consumed by H
2
, leading to decline in discharge current, qualitatively the sensing mechanism of micro-corona discharge type sensor for hydrogen gas is revealed.