Analysis Of Gases In Transformer Oil Research Articles

Adsorption and Sensing Mechanism of Late Transition Metal Doped MoTe2 Monolayers for Dissolved Gas Analysis in Transformer Oil: A First-Principles Study

Adsorption and Sensing Mechanism of Late Transition Metal Doped MoTe₂ Monolayers for Dissolved Gas Analysis in Transformer Oil: A First-Principles Study

Analysis of Microphone Coupling and Zero-Point Calibration Model for Non-Resonant Photoacoustic Spectroscopy

Dissolved Gas Analysis (DGA) of transformer insulation oil is an effective method for monitoring transformer operating conditions and diagnosing faults. Photoacoustic spectroscopy (PAS) is widely employed for online dissolved gas analysis in transformer oil. The positioning of the pressure equalization hole within the sound field significantly impacts the microphone’s sensitivity when coupled with the photoacoustic cell in non-resonant photoacoustic spectroscopy. The static temperature and humidity characteristics inside the photoacoustic cell also have a notable influence on the microphone’s output signal. Consequently, an analysis is performed to explore the relationship between the sensitivity of the photoacoustic spectrometer and temperature/humidity, leading to the optimization of the system configuration based on the microphone parameters. Moreover, the photoacoustic zero-point signal is influenced by the temperature and humidity levels within the photoacoustic cell. To address this problem, air mixtures at different humilities are measured, resulting in the establishment of a zero-point model for the background signal in Photoacoustic Spectroscopy (PAS). Subsequently, the experimental detection of acetylene under various humidity mixtures is conducted, successfully extracting effective signals for the measurement of 5 ppm acetylene gas. These results serve as evidence showcasing the efficacy of both the proposed structural optimization and zero-point model put forth in this study.

Adsorption Properties of Metal Oxides (ZnO, TiO2, Ag2O) Modified SnS2 Toward Dissolved Gas Analysis in Transformer Oil

Adsorption Properties of Metal Oxides (ZnO, TiO₂, Ag₂O) Modified SnS₂ Toward Dissolved Gas Analysis in Transformer Oil

Dissolved Gas Analysis in Transformer Oil Using Ni Catalyst Decorated PtSe2 Monolayer: A DFT Study

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 Ead 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.

Dissolved gas analysis in transformer oil using Ni-Doped GaN monolayer: A DFT study

In order to evaluate the running status of the transformer, through the detection of the dissolved gas in oil using highly sensitive gas sensor is proposed as an effective method. In this work, the adsorption characteristics of dissolved gases (H2, C2H2, CH4) in transformer oil on Ni-doped GaN (Ni-GaN) were analyzed based on density functional theory, and the potential of the Ni-GaN as a gas sensor was explored. The results show that the Ni-GaN has the largest adsorption energy to C2H2. On the other hand, the Ni-GaN has outstanding response to H2, C2H2 and CH4, and its response are 6.88 × 103, 6.57, 39.38, respectively. According to the analysis of frontier molecular orbital theory, the band gap of the Ni-GaN will increase after adsorption of three kinds of gases. This also confirms the sensing behavior of the Ni-GaN to three kinds of gases. In addition, the Ni-GaN has excellent desorption behavior for CH4. When the temperature is 398 K, the recovery time is only 8.90 s. Based on the working mechanism of the field effect transistor, by adjusting the strength of the applied electric field, it is found that the charge transfer in the adsorption process can be effectively adjusted. This work provides theoretical guidance for the development of the Ni-GaN gas sensitive sensor for detecting dissolved gas in transformer oil.

Cu-Doped MoSe2 Monolayer: A Novel Candidate for Dissolved Gas Analysis in Transformer Oil.

Dissolved gas analysis (DGA) in transformer oil is a workable approach to evaluate the operation status of transformers. In this paper, we proposed a Cu-doped Se-vacancy MoSe2 (Cu-MoSe2) monolayer as a promising sensing material for DGA based on first-principles theory. Three typical dissolved gases, namely, CO, C2H2, and C2H4, are the representatives to investigate the potential of the Cu-MoSe2 monolayer upon their adsorption and sensing. Our results indicate that Cu-doping causes strong n-doping for the Se-vacancy MoSe2 monolayer, and the Cu-MoSe2 monolayer exhibits strong chemisorption the three gas molecules, with a calculated adsorption energy (Ead) of −1.25, −1.06, and −1.16 eV, respectively. Such strong interactions lead to remarkable changes in the electrical conductivity of the Cu-MoSe2 monolayer, allowing its application as a resistance-type sensor. Besides, work function (WF) analysis shows the potential of the Cu-MoSe2 monolayer as a promising field-effect transistor sensor as well. It is our hope that our work can stimulate more leading-edge studies of the TM-doped MoSe2 monolayer for sensing applications in many fields.

Dissolved gas analysis in transformer oil using Sb-doped graphene: A DFT study

In order to improve the reliability of the transformer, reduce the maintenance cost of the transformer, online detection technology of transformer oil dissolved gases (H2, C2H2 and CH4) has become more important. Quick and accurate fault location is the research focus of this technology. In this paper, based on first principles density functional theory (DFT), the best Sb doping position was discussed, and adsorption systems of H2, C2H2 and CH4 on intrinsic graphene and Sb-doped graphene were built. The adsorption energy, charge transfer, bandgap, the energy of lowest unoccupied molecular orbital (LUMO), the energy of highest occupied molecular orbital (HOMO) and the total and partial density of states (DOS) of these adsorption systems were analyzed. The results showed that T doping site (Sb-CT) on the surface of graphene is the most stable site. And the intrinsic graphene has better adsorption and gas sensitivity to C2H2. Compared with H2, Sb-CT doped graphene has better sensing properties to C2H2 and CH4. It illustrates that Sb-doped graphene can be used in the overheated fault detection of the transformer.

First-Principles Insight into Pd-Doped ZnO Monolayers as a Promising Scavenger for Dissolved Gas Analysis in Transformer Oil.

ZnO monolayers with desirable n-type semiconducting properties are full of potential for sensing applications. In this work, we investigate using first-principles theory the adsorption and sensing behaviors of Pd-doped ZnO (Pd-ZnO) monolayers with two typical dissolved gases, namely, H2 and C2H2, to explore their sensing use for dissolved gas analysis in transformer oil. For Pd doping on the pristine ZnO monolayer, the TO site is identified as the most stable configuration with an Eb of −1.44 eV. For the adsorption of H2 and C2H2, chemisorption is determined given the large adsorption energy (Ead) and formation of new bonds. Analyses of the charge density difference and density of state provide evidence of the strong binding force of Pd–H and Pd–C bonds, while band structure analysis provides the sensing mechanism of the Pd-ZnO monolayer as a resistance-type sensor for H2 and C2H2 detection with high electrical responses. Also, analysis of the work function (WF) provides the possibility of selective detection of H2 and C2H2 using a Pd-ZnO monolayer-based field-effect transistor sensor given the opposite changing trend of the WF after their adsorption. Our work may broaden the application of ZnO-based gas sensors for application in the field of electrical engineering.

Adsorption properties of pristine and Co-doped TiO2(1 0 1) toward dissolved gas analysis in transformer oil

We theoretically studied the adsorption of dissolved gases H2, C2H2, and C2H4 in transformer oil and in pristine and Co-doped TiO2(1 0 1), respectively, on the basis of density functional theory calculations. First, the most stable structures of TiO2 and CoTiO2 surfaces were optimized. Then, the adsorption mechanism of dissolved gases on TiO2 and CoTiO2 surfaces were studied by analyzing adsorption energy, density of states, and molecular orbit theory. Pristine TiO2 exhibited weak adsorption and sensing performance to dissolved components. Co atom doping enhanced the adsorption behavior of TiO2-based material. H2, C2H2, and C2H4 molecules exhibited strong chemisorption on TiO2 surface after geometry optimization. The adsorption ability of these gas molecules on CoTiO2 surface is in the following order: C2H4 ＞ C2H2 ＞ H2. The conductivity of the CoTiO2 system decreased greatly after H2 and C2H4 adsorption, whereas a slight increase was observed after C2H2 adsorption. In summary, CoTiO2 could be a potential gas-sensing material for H2, C2H2, and C2H4 detection due to its prominent adsorption ability.

Adsorption behavior of Pd-doped SnS2 monolayer upon H2 and C2H2 for dissolved gas analysis in transformer oil

Dissolved gas analysis (DGA) is an effective technique to evaluate the operation status of the power transformer, and to guarantee the safe operation of the power system. Using density functional theory (DFT), we proposed the application of Pd-doped SnS2 (Pd-SnS2) monolayer as a sensing material to detect H2 and C2H2 in transformer oil. The electronic and geometric structures of Pd-doping behavior on SnS2 were also analyzed to give insight into the physicochemical property of the active surface. The adsorption configuration, density of state (DOS), frontier molecular orbital theory as well as recovery property of the adsorption systems were comprehensively studied to estimate the suitability of our proposed material for sensing application. Our calculations showed that Pd-doping exerts some deformations on the SnS2 monolayer and leads to the narrowed bandgap of such surface. Meanwhile, Pd-SnS2 monolayer has stronger adsorption performance upon C2H2 compared to H2. And the desirable interaction with C2H2 makes it possible for application of a resistance-type sensor given the good electrical response and recovery property. Our calculations are meaningful to suggest novel sensing material for application in the field of electrical engineering.

Dissolved gas analysis in transformer oil using Pd catalyst decorated MoSe2 monolayer: A first-principles theory

Dissolved gas analysis (DGA) by high-sensitive gas sensors is an effective manner to estimate the operation status of electrical transformers. In this paper, based on first-principles calculations, a novel 2D material, Pd-doped MoSe2 (Pd-MoSe2) monolayer, is explored as gas sensor or scavenger for detection or removal of typical gases in transformer oil, including H2, CO and C2H2, to guarantee the safety operation for the transformers. Adsorption configuration, density of state (DOS), recovery property, band structure and frontier molecular orbital theory are used to fully investigate the adsorption and desorption behaviors for Pd-MoSe2/gas systems. It is found that Pd-MoSe2 monolayer possesses strong adsorption performance towards CO molecule, thus allowing the removal of such pollutant to guarantee the safety operation of transformers. Besides, Pd-MoSe2 monolayer would be a promising candidate for C2H2 sensing due to the desirable adsorption and desorption behaviors. However, the poor adsorption behavior of Pd-MoSe2 monolayer upon H2 molecule even at ambient temperature reveals its unsuitability for H2 detector. Our results not only expound the transition metal doping effect on pure MoSe2 monolayer, but also provide a first insight into the potential application of Pd-MoSe2 monolayer in the field of electrical engineering.

Dissolved Gas Analysis in Transformer Oil Using Pt-Doped WSe2 Monolayer Based on First Principles Method

The composition and content of dissolved gases in transformer oil are closely related to the type of faults in the transformer and the severity of potential hazards. Dissolved gas analysis (DGA) in insulating oil is an important way to monitor the state of transformer equipment. CO, CH 4 , and C 2 H 2 are one of the dissolved gases in the transformer oil. Based on the density functional theory, the optimal adsorption site of the transition metal atom Pt on the surface of WSe 2 , one of the typical layered transition metal disulfides (LTMDs), is determined in the beginning. Attaining the adsorption behavior of these three gases on the surface of Pt-WSe 2 . The optimal structure of gas adsorption, charge transfer, adsorption energy, electronic density of states (DOS), deformation charge density (DCD), and frontier orbital are analyzed. As an electron acceptor, Pt-WSe 2 attracts electrons from all three gas molecules. The adsorption type of CO and C 2 H 2 molecules is chemisorption, whose adsorption effect is strong. The CH 4 adsorption is physical adsorption, whose adsorption effect is weak. The adsorption of all the three gas molecules leads to an increase in the bandgap of the Pt-WSe 2 , that is, the increase in the resistivity.

Dissolved hydrogen gas analysis in transformer oil using Pd catalyst decorated on ZnO nanorod array

A resistivity-type hydrogen (H2) sensor based on palladium (Pd)-decorated zinc oxide (ZnO) nanorod (NR) array has been developed to detect the dissolved H2 gas in the transformer oil. The Pd catalyst decorated on the ZnO NRs not only enhanced the H2 sensing properties at room temperature, but also played an important role to protect the ZnO NRs in liquid environment, which resulted long-term stability of the fabricated device. The H2 sensor had a temperature coefficient of resistance (TCR) of 68.45×10−4/°C, and showed the potential to detect H2 gas dissolved in transformer oil with a detection range of 5–1000ppm. The sensor showed high response towards H2 within 5–100ppm gas concentrations, which is critical to develop a H2 sensor for transformer oil. The kinetic H2 absorption/desorption in sensors was also investigated at different oil temperatures. Moreover, the fabricated sensor achieved high response, good repeatability, and long-term stability in oil, making it a promising candidate for transformer oil applications.