Design and Application of SF₆ Moisture and Density Sensor Based on Temperature Compensation Technology

In order to monitor the humidity and density inside SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> gas-insulated equipment in real time and ensure the reliable operation of the equipment, this paper designs a SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> moisture and density sensor with temperature compensation function. By integrating the resistance-capacitance humidity detection technology, the pressure-temperature combined density calculation model, and the temperature conversion method in the DL/T 506-2018 standard, accurate measurements of SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> gas moisture content and density are achieved. A humidity correction strategy based on a segmented temperature compensation algorithm is proposed to address the humidity measurement error caused by environmental temperature interference. Field verification at a 220 kV GIL transmission project demonstrates that the dew point deviation measured by the sensor is stable within $\pm 2^{\circ} \mathrm{C}$, meeting the accuracy requirements of resistance-capacitance humidity detection. This sensor provides highly reliable data support for the evaluation of SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> equipment status.