Investigation on abnormal phenomena of contacts using disconnecting switch and detachable bus in 300 kV GIS

Mukaiyama, Yoku; Takagi, Isao; Izumi, Kunikazu; Sekiguchi, Terukazu; Kobayashi, Akio; Sumikawa, Toshio

doi:10.1109/61.107272

Cited by 26 publications

(4 citation statements)

References 3 publications

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“…And the size of the box was determined to reach the actual gas density in GIS chamber. The density of SF 6 is about 6.0886 kg m −3 at 0.1 MPa and 20 • C. In this simulation box, the gas density is about 24.3907 kg m −3 , which is approximately equivalent to a GIS gas chamber filled with 0.4 MPa SF 6 .…”

Section: Simulation Detailsmentioning

confidence: 98%

“…Operating experience shows the defects such as poor contact will inevitably occur inside the chamber of SF 6 gas-insulated equipment [5], resulting in an increase in contact resistance at the defect. Under the action of long-term operating current, the local temperature may rise abnormally, resulting in the partial over-thermal fault (POF) [6]. When the temperature exceeds the thermal stability limit, the SF 6 insulating gas will decompose into sulfur fluorides SF x (x = 1 ∼ 5).…”

Section: Introductionmentioning

confidence: 99%

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Reactive molecular dynamics simulations on the pyrolysis of SF₆

Zeng

Zhang

et al. 2023

J. Phys. D: Appl. Phys.

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There are occasionally partial over-thermal faults in gas-insulated equipment inducing SF6 insulating medium to dissociate. It remains unclear at the atomic scale how this chemically stable gas pyrolyzes at high temperatures. Up to now, there is a lack of micro-level investigations on the molecular behavior of SF6 at high temperatures. Especially, it needs an effective force field to characterize the evolution of the reactions involving SF6 and low-fluorine sulfides. The paper aims to fill the gap in this field by performing reactive molecular dynamics (MD) simulations. In this work, MD simulations were carried out on a system consisting of more than 100 SF6 molecules using a new developed reactive force field (ReaxFF). The dissociation of SF6 and the subsequent reactions involving low-fluorine sulfides at high temperatures were simulated. The variation of all species in the system were recorded to investigate the effects of the temperature and pressure on the pyrolysis process. The obtained data was then used to establish the relationship between the reaction rate and temperature, thereby formulating Arrhenius law. Moreover, the trajectories of SF6 and other species were observed at the atomic level. Snapshots of key frames during the reaction helped us to explore the interaction mechanism of free F atoms with SF6 molecules and SF5 fragments. It was found that the early dissociation of SF6 mainly comes from the thermal vibrations of the molecule itself, while the later decomposition of SF6, SF5 and others is related to high-speed collisions by F atoms. This work contributes to the understanding of the mechanism of SF6 pyrolysis and lays a foundation for more MD investigations.

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Section: Simulation Detailsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Reactive molecular dynamics simulations on the pyrolysis of SF₆

Zeng

Zhang

et al. 2023

J. Phys. D: Appl. Phys.

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“…Operation reliability of GIB equipment is dependent on contact status of plug-in connector [1]. Even overheating on several seriously deteriorated contact elements could induce melting, partial discharge and flashover of GIB equipment, then cause catastrophic consequences such as GIB equipment damage and power grid knock down [2][3]. Influenced by the pressure-vessel insulation design, and cyclic mechanical and current loads during GIB equipment operation, contact interface of the GIB plug-in connector is subject to complex current-carrying wear processes [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Deterioration Behavior Analysis and LSTM-Based Failure Prediction of GIB Electrical Contact Inside Various Insulation Gases

et al. 2020

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Plug-in connector of gas insulated bus (GIB) could be subject to the wear and electrical contact resistance (ECR) deterioration processes under cyclic mechanical and current loads. A specific test platform is designed to simulate the current-carrying wear and ECR degradation process of Ag-plated GIB electrical contact spot inside SF6, N2 and Air insulation mediums under current loads. Worn surface morphology and chemical composition are observed and analyzed. Influence of insulation medium and current load on deterioration mechanism of GIB electrical contact are discussed. Raw ECR curve obtained from current-carrying experiment is smoothed by the exponentially weighted moving average (EWMA) method. A long short-term memory (LSTM) neural network is then proposed to realize both single-step and multi-step ECR and failure predictions of GIB electrical contact. Results show that adhesive wear on contact surface happened due to materials transfer. Deterioration of contact spot inside air medium is much severer than those in SF6 and N2 due to oxidation effect. Deterioration of contact spot inside SF6 medium under high current load is severer than those under low current load due to the change of wear behavior and chemical reactions. Compared with other methods, LSTM could achieve better performance in both singlestep and multi-step failure prediction of GIB electrical contact. INDEX TERMS electrical contact resistance (ECR); gas insulated bus (GIB); insulation gases; LSTM.

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“…There are a lot of researches on the distribution of power frequency electric field near AC overhead transmission lines. The main methods include charging simulation method, finite element method and boundary element method [5][6][7]. The research mainly focused on how the transmission line influence the building and the human body, but the research about the influence of the transmission line on the HLR is litter, which limits the improvement of the HLR insulation design technology.…”

Section: Introductionmentioning

confidence: 99%

Numerical Calculation and Analysis on the Surface Electric Field Characteristics of Hot-Line Robot

Zhong¹,

Wu²,

Xiang³

2018

dtcse

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Hot-Line robot (HLR) is an automatic transmission line inspection device developed in recent years. The mounting device should be contacted with the high voltage transmission line thus to realize the voltage transfer at the first operation stage of the HLR, and the HLR device which is regarded as a floating electrode might be damaged by discharge induced by the filed distortion during the voltage transfer process. The surface electric field of HLR device is optimized to improve its operation reliability, and a static-electric field finite element model of the transmission line which includes the HLR device is developed in this paper, and the dynamic surface electric filed characteristics of HLR during elevating operation process are studied by the finite elements model. Results show that influenced by the electric field which induced by high-voltage transmission line, the induced electric field can be generated on the surface of HLR during the process of elevating operation. The induced electric field distorts on the edge chamfer of HLR device which is regarded as a floating electrode. The maximum field strength position is influenced by the arrangement of the overhead wire conductor, and the edge chamfers are the key points of the electric field optimization of the HLR. The results of this study could provide theoretical basis and technical support for the optimization of HLR insulation characteristics, which is of great value to improve its operation reliability.

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Investigation on abnormal phenomena of contacts using disconnecting switch and detachable bus in 300 kV GIS

Cited by 26 publications

References 3 publications

Reactive molecular dynamics simulations on the pyrolysis of SF₆

Reactive molecular dynamics simulations on the pyrolysis of SF₆

Deterioration Behavior Analysis and LSTM-Based Failure Prediction of GIB Electrical Contact Inside Various Insulation Gases

Numerical Calculation and Analysis on the Surface Electric Field Characteristics of Hot-Line Robot

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Investigation on abnormal phenomena of contacts using disconnecting switch and detachable bus in 300 kV GIS

Cited by 26 publications

References 3 publications

Reactive molecular dynamics simulations on the pyrolysis of SF6

Reactive molecular dynamics simulations on the pyrolysis of SF6

Deterioration Behavior Analysis and LSTM-Based Failure Prediction of GIB Electrical Contact Inside Various Insulation Gases

Numerical Calculation and Analysis on the Surface Electric Field Characteristics of Hot-Line Robot

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Reactive molecular dynamics simulations on the pyrolysis of SF₆

Reactive molecular dynamics simulations on the pyrolysis of SF₆