Fully kinetic model of breakdown during sheath expansion after interruption of vacuum arcs

Wang, Zhenxing; Wang, Haoran; Zhou, Zhipeng; Tian, Ying; Geng, Yingsan; Wang, Jianhua

doi:10.1063/1.4961420

Cited by 24 publications

(12 citation statements)

References 29 publications

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“…The ion sheath is quite thin, and it withstands the whole voltage drop between the contacts. Hence a high electric-field can be generated inside [8].…”

Section: Discussionmentioning

confidence: 99%

“…In addition, the metallic vapor can also efficiently limit the expansion and even shrink the ion sheath, which leads to a higher electric field near the anode [8]. Finally, aided by the electric field near the anode, a liquid protrusion develops in the anodic molten region that can serve as a trigger for a postarc breakdown.…”

Section: Discussionmentioning

confidence: 99%

“…After the current reaches zero and the arc extinguishes, all metallic atoms should be dissipated from the gap, and the dielectric strength is recovered [7]. Otherwise, a breakdown may occur and the interruption becomes unsuccessful [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Optical absorption spectroscopy of metallic (Cr) vapor in a vacuum arc

Wang

Liu

et al. 2018

J. Phys. D: Appl. Phys.

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The measurement of the metallic vapor density in a vacuum arc is crucial to acquire a better understanding of both the anodic activity and the dielectric recovery process in vacuum interrupters. The objective of this study was to measure the chromium vapor density and its axial distribution within the gap between the chromium contacts. Optical absorption spectroscopy (OAS) with a broadband light-source is adopted for this investigation. The results show that when the vacuum arc burns in the diffuse mode, the metallic vapor density maxima occur near the electrodes during the arcing period. At the peak current, the vapor density near the electrodes can be as high as 2.5 × 1018 m−3. With the decrease of the arc current, the metallic vapor density near the electrodes decreases as well, while the vapor density in the center of the gap remains nearly constant during the arcing period. At current zero, the metallic vapor in the gap has a nearly uniform distribution of about 3 × 1017 m−3. When the vacuum arc burns in the high-current mode, the metallic vapor density near the anode is lower than that in other areas until the vacuum arc becomes diffuse. Then, the evaporation process of the anodic molten region starts to play an important role and the metallic vapor density near the anode increases. At current zero, the metallic vapor has a density of about 4 × 1018 m−3 near the anode, which is much higher than anywhere else. Because the metallic vapor density at current zero is too low to cause a Townsend avalanche, extra factors are needed for initiating the breakdown in the post-arc phase. These factors could include a residual plasma within the gap and the behavior of the liquid metal in the molten anodic region.

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“…The ion sheath is quite thin, and it withstands the whole voltage drop between the contacts. Hence a high electric-field can be generated inside [8].…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Optical absorption spectroscopy of metallic (Cr) vapor in a vacuum arc

Wang

Liu

et al. 2018

J. Phys. D: Appl. Phys.

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“…At the instant of CZ, the maximum remaining ion density for the 9.25 µs cut-off time case was almost three times that of the 37 µs case. The significantly increased ion density may cause difficulties for the dielectric recovery strength of VCBs during the post-arc period [46].…”

Section: The Effects Of the Cut-off Timementioning

confidence: 99%

3D hybrid modelling of the extinction of multiple cathode spots in vacuum

Cao

Wang

Chen

et al. 2020

J. Phys. D: Appl. Phys.

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Plasma transport during continuous extinction processes from high-current arcs to full extinction is an important issue in the study of vacuum arcs. However, to describe this transition, the traditional methods, magneto hydrodynamics or particle-in-cell, are limited by either accuracy or efficiency. In this paper, we developed a fully 3D hybrid plasma simulation algorithm to study the extinction process of multiple cathode spots in a vacuum environment. Cathode spots are modelled as independent plasma sources rather than treating the whole cathode surface as an indivisible source. For a better balance between efficiency and accuracy, ions are modelled as particles and electrons are treated as a massless fluid. Using this model, the effects of cut-off time and the locations of cathode spots on the extinction process are studied. The results show that during an extinction process, the total number of ions between the electrodes gradually decreases and the mean velocity of the ions gradually increases. When the current approaches zero, two regions can be observed in the gap: the separated jet region, and the common plasma channel region. The last three surviving cathode spots have significant impacts on the ion distribution at current zero, whose values depend on the distances to them. The closer together the three cathode spots are, the higher the value that the local ion density will reach. In addition, at current zero, the maximum ion density appears near the last extinguished cathode spot.

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“…When the post-arc dielectric recovery is faster than the transient recovery voltage, the breakdown will not occur, on the contrary, the occurrence of a breakdown means breaking fails. The post-arc dielectric recovery depends mainly on the initial post-arc conditions such as residual plasma density and metal vapor density between contacts, the temperature of the contact surface, which are caused by arc evolution behaviour in arcing process [5], [6]. Therefore, many researchers focus on the arc behaviour of vacuum circuit breakers.…”

Section: Introductionmentioning

confidence: 99%

Study on Arc Evolution Behaviour of Breaking Short Circuit Current for a Fast Vacuum Circuit Breaker

Wang¹,

Guan²,

Zhang³

et al. 2021

B&H Electrical Engineering

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A fast vacuum circuit breaker (FVCB), driven by an electromagnetic repulsion mechanism, has an extremely short opening time, and in coordination with the controlled switching technology contributes to breaking a short circuit current with the minimum arcing time. The objective of the paper is to determine the arc evolution behaviour of fast vacuum circuit breakers with a minimum arcing time. A 40.5 kV vacuum interrupter (VI) was used, which was equipped with a pair of CuCr50 (Cr 50 wt%) axial magnetic field (AMF) contacts. The diameters of the contact were Φ50mm, Φ58 mm and Φ65 mm respectively. The arc evolution behaviour in the drawn arc experiment was photographed by a high-speed camera through a glass envelope of the VI. The experiment results showed that an initial intense arc tended to evolve into a diffuse arc when the arcing time is larger than a critical arc diffusion time under a certain opening velocity. The critical arc diffusion time for the vacuum arc is defined as arc evolving from the instant of contact separation to an appearance of separated cathode spots. For a Φ50 mm cup-type AMF contact, the critical arc diffusion time decreases from 0.7 ms to 0.46 ms, with the increase of the opening velocity from 2.52 m/s to 4.65 m/s. What’s more, for a Φ58 mm cup-type AMF contact, the critical arc diffusion time decreases from 1.0 ms to 0.58 ms with the increase of the opening velocity from 2.52 m/s to 4.65 m/s. For a Φ65 mm cup-type AMF contact, the critical arc diffusion time decreases from 1.30 ms to 0.64 ms with the increase of the opening velocity from 2.52 m/s to 4.65 m/s. The critical arc diffusion time increases with the increase of the diameter of the contact under the same opening velocity.

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Fully kinetic model of breakdown during sheath expansion after interruption of vacuum arcs

Cited by 24 publications

References 29 publications

Optical absorption spectroscopy of metallic (Cr) vapor in a vacuum arc

Optical absorption spectroscopy of metallic (Cr) vapor in a vacuum arc

3D hybrid modelling of the extinction of multiple cathode spots in vacuum

Study on Arc Evolution Behaviour of Breaking Short Circuit Current for a Fast Vacuum Circuit Breaker

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