New sensor for gases dissolved in transformer oil based on solid oxide fuel cell

Due to the poor anti-jamming performance, less gas species, low detection accuracy, short life, medium leaking or carbon monoxide poisoning and other defects that current sensors for gases dissolved in transformer oil have, a SOFC-based multi-component gas sensor has been designed. The physical, chemical and electrochemical mechanisms of gases in the SOFC have been analyzed, and the mathematical model which contains the static, dynamic and load effects has been established. And the model parameters have been optimized in this paper. The results showed that: (1) temperature is the decisive factor for the static characteristic of the sensor, and the accuracy of temperature should be controlled within ± 0.1 °C to achieve the 0.1 μL/L detection limit of C2H2. (2) The polarization resistance is inversely proportional to the input gas concentrations, while the open-circuit voltage is proportional to them. (3) The relationship between the short-circuit current and the square of input gas concentration is direct proportion, and the polarization resistance is the determinant of sensor dynamic characteristics. Finally, a gas experimental system has been built to verify the above conclusions. This gas sensor can realize the high-precision detection for multi-component gases dissolved in transformer oil effectively.