{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T04:14:45Z","timestamp":1788236085160,"version":"build-2803163510"},"reference-count":32,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"scientific and technological project of Guoneng Guangtou Beihai Power Generation Co., Ltd.","award":["BHDC-2025-FW-048"],"award-info":[{"award-number":["BHDC-2025-FW-048"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Monitoring gas generated by internal faults in high-voltage switchgear is crucial for early warning and condition assessment; however, the diffusion process between gas generation and detection is currently widely overlooked, which severely compromises the accuracy of gas-based assessments. Implementing \u201cvirtual sensing\u201d for high-voltage switchgear using digital twin technology to supplement data from physical sensors can effectively support digitalised and intelligent operation and maintenance. To this end, taking the characteristic gases of partial discharge as the subject of study, we first constructed a 1:1 scale digital twin model of internal gas diffusion within a 10 kV high-voltage switchgear. Calculations revealed significant differences in the diffusion processes of various gases: CO diffuses rapidly and mixes strongly, making it suitable for early warning; CO2 and O3 tend to accumulate in lower regions and stagnant zones, making them sensitive to faults in the lower sections; whilst NO reflects the channelling effect within the structure. Subsequently, a test platform comprising a 10 kV high-voltage switchgear unit and a gas detector was established for experimental validation. This revealed the trends in gas concentration changes, response sequences and peak behaviour at different fault locations, thereby verifying the validity of the proposed model. The maximum error in concentration balance was within 10 percent, providing a theoretical basis and engineering reference for the optimised placement of gas sensors in high-voltage switchgear and for fault tracing and localisation.<\/jats:p>","DOI":"10.3390\/s26175538","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T03:19:26Z","timestamp":1788232766000},"page":"5538","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Study on a Digital Twin Method for Modelling the Diffusion Process of Fault Gases Inside High-Voltage Switchgear Combining Virtual and Physical Models"],"prefix":"10.3390","volume":"26","author":[{"given":"Xin","family":"Wang","sequence":"first","affiliation":[{"name":"Guoneng Guangtou Beihai Power Generation Co., Ltd., Beihai 536017, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"given":"Hao","family":"Luo","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Power Transmission Equipment Technology, School of Electrical Engineering, Chongqing University, Chongqing 400044, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,31]]},"reference":[{"key":"ref_1","first-page":"19","article-title":"Study on the Characteristic Gases of Partial Discharges in Air Circuit Breaker Switchgear Based on Chemical Reaction Rate Theory","volume":"59","author":"Zhang","year":"2023","journal-title":"High Volt. Appar."},{"key":"ref_2","first-page":"69","article-title":"Experimental and Simulation Studies on the Decomposition Components of Partial Discharges in Air-Insulated Switchgear","volume":"10","author":"Chen","year":"2016","journal-title":"China South. Power Grid Technol."},{"key":"ref_3","first-page":"3948","article-title":"Correlation between Partial Discharges and Air Decomposition Components in Switchgear with Pin-Plate Defects","volume":"42","author":"Yinggang","year":"2016","journal-title":"High Volt. Technol."},{"key":"ref_4","first-page":"769","article-title":"Experimental Simulation and Analysis of Fault-Derived Gases in Switchgear","volume":"54","author":"Zhenyu","year":"2021","journal-title":"J. Wuhan Univ. (Eng. Ed.)"},{"key":"ref_5","first-page":"3958","article-title":"Study on the Diffusion Behaviour of Characteristic Decomposition Gases of SF6 within GIS Compartments under Localised Overheating","volume":"49","author":"Di","year":"2025","journal-title":"Power Syst. Technol."},{"key":"ref_6","unstructured":"(2022). Diagnosis of Partial Discharge Based on the Air Components for the 10 kV Air-Insulated Switchgear. Sensors, 22."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wan, L.J., Zhao, X.H., and Li, K. (2024). Online Detection of Hydrogen Fluoride under Corona Discharge in Gas-Insulated Switchgear Based on Photoacoustic Spectroscopy. Sensors, 24.","DOI":"10.3390\/s24092806"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kim, Y., Goo, S.G., and Lim, J.S. (2022). Multi-Gas Analyzer Based on Tunable Filter Non-Dispersive Infrared Sensor: Application to the Monitoring of Eco-Friendly Gas Insulated Switchgears. Sensors, 22.","DOI":"10.2139\/ssrn.4189358"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6295","DOI":"10.1021\/acssensors.6c01416","article-title":"Accelerating Discovery of WX2-Based Gas Sensors (X = S, Se, and Te) for C4F7N Decomposed Species via Density Functional Theory and Machine Learning","volume":"11","author":"Cui","year":"2026","journal-title":"ACS Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"065109","DOI":"10.1088\/1361-6501\/ad3412","article-title":"Domain-alignment multitask learning network for partial discharge condition assessment with digital twin in gas-insulated switchgear","volume":"35","author":"Yan","year":"2024","journal-title":"Meas. Sci. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1785","DOI":"10.1049\/gtd2.13156","article-title":"A novel meta-learning network for partial discharge source localization in gas-insulated switchgear via digital twin","volume":"18","author":"Yan","year":"2024","journal-title":"IET Gener. Transm. Distrib."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"34303","DOI":"10.1038\/s41598-025-15626-0","article-title":"Research on digital twin diagnosis model for the thermal-electric field of high-voltage switchgears","volume":"15","author":"Ding","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"21868","DOI":"10.1038\/s41598-026-52842-8","article-title":"Uncertainty-aware temperature field reconstruction from sparse samples and sensing via latent-space enhancement for GIS digital twin applications","volume":"16","author":"Wang","year":"2026","journal-title":"Sci. Rep."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Jia, C.L., Zhao, W.B., Zhu, Y., Lu, W., and Tang, Z. (2022). A Numerical Study on the Decomposition and Diffusion Characteristics of SF6 in Gas-Insulated Switchgear with Consideration of the Temperature Rising Effect. Energies, 15.","DOI":"10.3390\/en15217834"},{"key":"ref_15","unstructured":"Jiacheng, D. (2023). A Study on the Diffusion of SF6 Decomposition Products and GIS Fault Localisation Based on Computational Fluid Dynamics Simulation, North China Electric Power University."},{"key":"ref_16","first-page":"2478","article-title":"Calculation of the Diffusion Characteristics of Decomposition Gases in SF6 and SF6\/N2 within Gas-Insulated Transmission Pipelines","volume":"35","author":"Ming","year":"2020","journal-title":"J. Electr. Eng."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhou, Z., Feng, B., and Wam, T. (2012). Investigation on diffusion process of water molecules in sulfur hexafluoride electric equipments based on CFD technique. Power Engineering and Automation Conference, IEEE.","DOI":"10.1109\/PEAM.2012.6612507"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Monroy, J.G., Hern\u00e1ndez-Bennetts, V., Fan, H., Lilienthal, A., and Gonz\u00e1lez-Jim\u00e9nez, A.J. (2017). GADEN: A 3D Gas Dispersion Simulator for Mobile Robot Olfaction in Realistic Environments. Sensors, 17.","DOI":"10.3390\/s17071479"},{"key":"ref_19","first-page":"1","article-title":"Simulation Analysis of Temperature Rise in Thermal Faults of Air-Insulated Switchgear Based on Multi-Physics Coupling","volume":"56","author":"Yi","year":"2020","journal-title":"HighVolt. Electr. Appar."},{"key":"ref_20","first-page":"38","article-title":"Multi-physics Coupled Field Simulation and Analysis of Gas-Insulated Switchgear","volume":"55","author":"Lujun","year":"2019","journal-title":"High Volt. Electr. Appar."},{"key":"ref_21","first-page":"6","article-title":"Numerical Calculation and Analysis of Temperature and Humidity Fields in the Cable Compartment of High-Voltage Switchgear","volume":"53","author":"Yunpeng","year":"2017","journal-title":"High Volt. Appar."},{"key":"ref_22","first-page":"5095","article-title":"Three-Dimensional Numerical Simulation Study of Temperature and Humidity Distributions in High-Voltage Switchgear","volume":"34","author":"Yuan","year":"2019","journal-title":"J. Electr. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1021\/ie50677a007","article-title":"A New Method for Prediction of Binary Gas-Phase Diffusion Coefficients","volume":"58","author":"Fuller","year":"1966","journal-title":"Ind. Eng. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Sui, Z.W., Yuan, X.B., Cai, B.P., Ye, F., Duan, Z., Shao, X., Zhou, X., and Hu, X. (2025). Integrated Bayesian and Particle Swarm Approaches for Enhanced Gas Leak Detection in Complex Commercial Structures. Sensors, 25.","DOI":"10.3390\/s25051481"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Suawa, F., and Herglotz, C. (2025). Optimizing Sensor Placement for Event Detection: A Case Study in Gaseous Chemical Detection. Sensors, 25.","DOI":"10.3390\/s25082397"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1016\/j.jlp.2016.03.004","article-title":"A CFD-based approach for gas detectors allocation","volume":"44","author":"Mannan","year":"2016","journal-title":"J. Loss Prev. Process Ind."},{"key":"ref_27","unstructured":"Cichang, Z., and Xuezong, L. (1983). Computational Fluid Dynamics, Beijing Science Press."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1049\/smt2.12147","article-title":"Study on characteristics gases of metal protrusions partial discharge in 10-kV air-insulated switchgear","volume":"17","author":"Tan","year":"2023","journal-title":"IET Sci. Meas. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"104279","DOI":"10.1016\/j.compfluid.2019.104279","article-title":"A coupled finite-volume solver for numerical simulation of electrically-driven flows","volume":"193","author":"Pimenta","year":"2019","journal-title":"Comput. Fluids"},{"key":"ref_30","unstructured":"Fujun, W. (2004). Computational Fluid Dynamics Analysis\u2014Principles and Applications of CFD Software, Tsinghua University Press."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"8927","DOI":"10.1016\/j.ijhydene.2018.07.130","article-title":"Pressure effects of an ignited release from onboard storage in a garage with a single vent","volume":"44","author":"Brennan","year":"2019","journal-title":"Int. J. Hydrog. Energy"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"075106","DOI":"10.1063\/1.4958883","article-title":"Study on the characteristic decomposition components of air-insulated switchgear cabinet under partial discharge","volume":"6","author":"Gui","year":"2016","journal-title":"AIP Adv."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/17\/5538\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T03:23:00Z","timestamp":1788232980000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/17\/5538"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,31]]},"references-count":32,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["s26175538"],"URL":"https:\/\/doi.org\/10.3390\/s26175538","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,31]]}}}