To address the problem of low space utilization of existing rigid Ultra-High Frequency (UHF) sensors for partial discharge (PD) in Gas-Insulated Switchgears (GIS) and the problem of disrupting the electric field distribution inside the GIS. This paper draws on the idea of flexible wearable antennas and introduces planar monopole antennas commonly used in the communication field as GIS PD detection sensors and carried out research on flexible planar monopole sensing technology built into GIS PD. The VSWR of monopole antenna in the UHF low band is optimized by the meandering technique. The size of the designed flexible antenna is 142 mm × 195 mm × 0.28 mm. The simulation and physical test results show that the improved monopole antenna with meandering technology has a VSWR of ≤2 in the frequency bands 570 MHz–830 MHz, 1.38 GHz–1.8 GHz, and 2.2 GHz–2.76 GHz when the bending radius is 0 mm, 200 mm, and 400 mm, respectively. The VSWR in the frequency band 450 MHz–3 GHz is ≤5. A 220 kV GIS PD detection platform was built to test the performance of the designed antenna, and the results showed that the antenna could detect the PD signal after bending deformation with a high Signal Noise Ratio (SNR).

Spiral antenna sensors are commonly used in partial discharge (PD) ultra-high frequency (UHF) detection in gas-insulated switchgears (GISs). However, most of the existing UHF spiral antenna sensors are based on a rigid base and balun, such as FR-4. The safe built-in installation of antenna sensors requires the complex structural transformation of GISs. To solve this problem, a low-profile spiral antenna sensor is designed based on a polyimide (PI) flexible base, and its performance is optimized by improving the clearance ratio. The simulation and measurement results show that the profile height and diameter of the designed antenna sensor is 0.3 mm and 137 mm, which is 99.7% and 25.4% smaller than the traditional spiral antenna. Under a different bending radius, the antenna sensor can maintain VSWR ≤ 5 in 650 MHz~3 GHz, and its maximum g_re is up to 6.1 dB. Finally, the PD detection performance of the antenna sensor is carried out on a real 220 kV GIS. The results show that, after being built in, the PD with a weak discharge magnitude of 4.5 pC can be effectively detected by the antenna sensor, and the antenna sensor has the ability to quantify the severity of PD. In addition, through the simulation, the antenna sensor has potential for the detection of micro water in GISs.

In this paper, the first-principles theory is used to explore the adsorption behavior of Ni catalyst decorated PtSe₂ (Ni-PtSe₂) monolayer toward the dissolved gas in transformer oil, namely CO and C₂H₂. Some Ni atoms from the catalyst are trapped in the Se vacancy on the pure PtSe₂ surface. The geometry configurations of Ni-PtSe₂ monolayer before and after gas adsorption, the electronic property of Ni-PtSe₂ monolayer upon gas adsorption, and the sensibility and recovery property of Ni-PtSe₂ monolayer are explored in this theoretical work. Through the simulation, the ${\mathrm{E}}_{\mathrm{ad}}$ of CO and C₂H₂ gas adsorption systems are calculated as −1.583 eV and −1.319 eV, respectively, both identified as chemisorption and implying the stronger performance of the Ni-PtSe₂ monolayer on CO molecule, which is further supported by the DOS and BS analysis. According to the formula, the sensitivity of Ni-PtSe₂ monolayer towards CO and C₂H₂ detection can reach up to 96.74% and 99.91% at room temperature (298 K), respectively, which manifests the favorable sensing property of these gases as a chemical resistance-type sensor. Recovery behavior indicates that the Ni-PtSe₂ monolayer is a satisfied gas scavenger upon the noxious gas dissolved in transformer oil, but its recovery time at room temperature is not satisfactory. To sum up, we monitor the status of the transformer to guarantee the stable operation of the power system through the Ni-PtSe₂ monolayer upon the detection of CO and C₂H₂, which may realize related applications, and provide the basis and reference to cutting-edge research in the field of electricity in the future.

Mo₂C is a two-dimensional material with high electrical conductivity, low power consumption, and catalytic effect, which has promising applications in the field of microfluidic gas detection. First principles were used to study the adsorption characteristics of Mo₂C monolayer on four typical decomposition gases of SF₆ (H₂S, SO₂, SOF₂, and SO₂F₂), and to explore the feasibility of its application in the detection of SF₆ decomposition components. The results showed that Mo₂C chemisorbed all four gases, and the adsorption capacity was H₂S < SO₂ < SOF₂ < SO₂F₂. The adsorption mechanism of Mo₂C as a microfluidic sensor was analyzed in combination with its charge-density difference and density of states. On the other hand, the different work-function change trends after adsorbing gases provide the possibility for Mo₂C to selectively detect gases as a low-power field-effect transistor sensor. All content can be used as theoretical guidance in the realization of Mo₂C as a gas-sensitive material for the detection of SF₆ decomposition components.

The use of flexible, built-in, ultra-high-frequency (UHF) antenna sensors is an effective method to solve the weak high-frequency electromagnetic wave signal sensing of partial discharge (PD) inside gas-insulated switchgears (GISs), and the compatibility of flexible UHF antenna sensor substrate materials and SF6/N2 mixtures is the key to the realization of a flexible UHF antenna sensor inside a GIS. Based on this, this paper builds an experimental platform for the compatibility of a 30% SF6/70% N2 gas mixture and a PD flexible UHF antenna sensor substrate and conducts compatibility experiments between the 30% SF6/70% N2 gas mixture and PD flexible UHF antenna sensor substrate under different temperatures in combination with the actual operating temperature range of the GIS. In this article, a Fourier transform infrared spectrometer, scanning electron microscope and X-ray photoelectron spectrometer were used to test and analyze the gas composition, the surface morphology and the elemental change in the PD flexible UHF antenna sensor substrate, respectively. PET material will be slightly oxidized under the environment of a 30% SF6/70% N2 gas mixture at 110 °C, PI material will generate metal fluoride under the environment of a 30% SF6/70% N2 gas mixture and only PDMS material will remain stable under the environment of a 30% SF6/70% N2 gas mixture; therefore, it is appropriate to use PDMS substrate in the development of flexible UHF antenna sensors.