Real-Time Monitoring of Air Discharge in a Switchgear by an Intelligent NO₂ Sensor Module

Abstract

An air-insulated power equipment adopts air as the insulating medium and is widely implemented in power systems. When discharge faults occur, the air produces decomposition products represented by NO 2 . The efficient NO 2 sensor enables the identification of electrical equipment faults. However, singlesensor-dependent NO 2 detection is vulnerable to interfering gases. Implementing the sensor array could reduce the interference and improve detection efficiency. In the field of NO 2 detection, In 2 O 3 sensors have exhibited tremendous advantages. In our work, four composites based on In 2 O 3 are integrated into sensor arrays, which could detect 250 ppb of NO 2 and exhibit excellent selectivity when simultaneously exposed to CO. To further reduce the impact of humidity on gas-sensing performance, a convolutional neural network and a long short-term memory model equipped with an attention mechanism are proposed to evaluate NO 2 concentration within 1 ppm, and the detection error is 63.69 ppb. In addition, the NO 2 concentration estimation platform based on a microgas sensor is established to detect air discharge faults. The average concentration of NO 2 generated by 10 consecutive discharge faults at 15 kV is 726.58 ppb, which indicates severe discharge in the switchgear. Our NO 2 estimation method has great potential for largescale deployment in low-and medium-voltage switchgears.

Defective Cr2CTx-based sensors with high sensitivity for NO2 detection at room temperature

“…1,2 Thus, the medical sciences, industrial control, and environmental monitoring sectors have all paid close attention to developing room temperature NO 2 sensor technologies. 3,4 Conventional NO 2 sensors face several challenges, notably insufficient sensitivity and stability at ambient temperature. 5 Specifically, most of the gas sensor materials currently used are metal oxide semiconductors, which are prone to degradation or oxidation in high temperature and high humidity environments, affecting their long-term stability; in addition, the interlayer interactions of metal oxide semiconductors are usually strong, resulting in a fixed interlayer spacing, thus affecting their sensing performance, and their low specific surface area also limits their active surface area during gas adsorption; finally, their surface chemical properties are relatively stable, making it difficult to further functionalize and modify their surfaces, thereby increasing the difficulty of improving their sensing performance.…”