Current zero behaviour of a gas-blast arc. Part 1: Nitrogen

Fang, Michael; Lin, Wamei

doi:10.1049/ip-a-2.1990.0029

Cited by 4 publications

(7 citation statements)

References 15 publications

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“…It was shown that the arc model based on laminar flow could give satisfactory agreement between predicted and measured arc temperature, arc radius, electrical field and pressure at important locations in the nozzle. It was also shown in the study of Fang and Lin [11] that arc theory based on laminar flow could predict the critical rate of rise of recovery voltage (RRRV) within 25% of that measured for a nitrogen arc. Such an agreement is considered acceptable for circuit breakers due to the large error bar of the measured RRRV values as a result of shot to shot variation.…”

Section: Introductionmentioning

confidence: 91%

“…The axial and radial components of are given by (9) For axisymmetric arc, the azimuthal magnetic flux density can be calculated by (10) where is the axial component of the current density and μ 0 the permeability of free space. The two components of Lorentz force are given by (11) The approximate radiation transport model of Zhang et al [10] is adopted to calculate the net radiation loss in the energy equation. In the arc core, the boundary of which is defined at the point of 83% of the axis temperature, q in the energy conservation equation is equal to the net emission coefficient (NEC), which is a function of the local pressure, temperature and the arc's radiation radius.…”

Section: The Governing Equationsmentioning

confidence: 99%

“…It is therefore commonly assumed that turbulence in nitrogen or air (due to nitrogen being its major constituent) does not play a dominant role in arc extinction around current zero. However, caution must be exercised in assessing the importance of turbulence as the role of turbulence has only been tested with a single experimental case for a nitrogen nozzle arc at P 0 = 23 atm with di/dt = 36 Aμs -1 [11]. Thus, no firm conclusions can be drawn regarding the importance of turbulence in air or nitrogen arcs.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas

Liu¹,

Zhang²,

Yan³

et al. 2016

J. Phys. D: Appl. Phys.

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It is shown that the arc model based on laminar flow cannot predict satisfactorily the voltage of an air arc burning in a supersonic nozzle. The Prandtl mixing length model (PML) and a modified k-epsilon turbulence model (MKE) are used to introduce turbulence enhanced momentum and energy transport. Arc voltages predicted by these two turbulence models are in good agreement with experiments at the stagnation pressure (P 0) of 10 bar. The predicted arc voltages by MKE for P 0 = 13 bar and 7 bar are in better agreement with experiments than those predicted by PML. MKE is therefore a preferred turbulence model for air nozzle arc. There are two peaks in ρC P of air at 4000 K and 7000 K due, respectively, to the dissociation of oxygen and that of nitrogen. These peaks produce corresponding peaks in turbulent thermal conductivity, which results in very broad radial temperature profile and a large arc radius. Thus, turbulence indirectly enhances axial enthalpy transport, which becomes the dominant energy transport process for the overall energy balance of the arc column at high currents. When the current reduces, turbulent thermal conduction gradually becomes dominant. The temperature dependence of ρC P has a decisive influence on the radial temperature profile of a turbulent arc, thus the thermal interruption capability of a gas. Comparison between ρC P for air and SF 6 shows that ρC P for SF 6 has peaks below 4000 K. This renders a distinctive arc core and a small arc radius for turbulent SF 6 , thus superior arc quenching capability. It is suggested, for the first time, that ρC P provides guidance for the search of a replacement switching gas for SF 6 .

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Section: Introductionmentioning

confidence: 91%

Section: The Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas

Liu¹,

Zhang²,

Yan³

et al. 2016

J. Phys. D: Appl. Phys.

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“…Specifically, the electron density near the zero current point is an important parameter that determines the cut-off efficiency [8][9][10]. Specifically, the electron density near the zero current point is an important parameter that determines the cut-off efficiency [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…Understanding the basic characteristics of arc discharges is extremely important in resolving these problems in SF 6 gas circuit breakers. Specifically, the electron density near the zero current point is an important parameter that determines the cut-off efficiency [8][9][10]. Furthermore, a knowledge of the electron density is indispensable for determining the arc conductivity.…”

Section: Introductionmentioning

confidence: 99%

Measurements of Electron Density and Electron Temperature of Arc Discharge Plasmas Containing Metallic Vapors Using Laser Thomson Scattering

Tomita

Yoshitake

Uchino

et al. 2014

Electrical Engineering Japan

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Laser Thomson scattering (LTS) was applied to arc discharges generated in the atmosphere to measure electron density (n e ) and electron temperature (T e ). The electrode gap was 0.8 mm, and the electrode diameter was 1 mm. The applied voltage was 6 kV, the peak current was 600 A, and the decay time of the voltage and current was 25 μs. The spatiotemporal evolution of n e and T e was measured 10, 30, and 50 μs after discharge initiation. At these times, the obtained values of n e and T e were estimated to be in the ranges of (0.8 to 2.0) × 10 23 m −3 and 1.0 to 2.2 eV, respectively. These values were consistent with those evaluated using Saha's thermodynamic equation at 1 atm. It was also found that the decay of the arc discharge produced using the tungsten-copper electrodes was much faster than that produced using the tungsten electrodes. C⃝ 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 188(4): 1-8, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com).

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Two-dimensional electron density characterisation of arc interruption phenomenon in current-zero phase

Inada¹,

Kamiya²,

Matsuoka³

et al. 2017

J. Phys. D: Appl. Phys.

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Two-dimensional electron density imaging over free burning arcs and gas-blast arcs was conducted at current zero using highly sensitive Shack–Hartmann type laser wavefront sensors in order to experimentally characterise electron density distributions for the success and failure of arc interruption in the thermal reignition phase. The experimental results under an interruption probability of 50% showed that free burning arcs with axially asymmetric electron density profiles were interrupted with a success rate of 88%. On the other hand, the current interruption of gas-blast arcs was reproducibly achieved under locally reduced electron densities and the interruption success rate was 100%.

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Current zero behaviour of a gas-blast arc. Part 1: Nitrogen

Cited by 4 publications

References 15 publications

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas

Measurements of Electron Density and Electron Temperature of Arc Discharge Plasmas Containing Metallic Vapors Using Laser Thomson Scattering

Two-dimensional electron density characterisation of arc interruption phenomenon in current-zero phase

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Current zero behaviour of a gas-blast arc. Part 1: Nitrogen

Cited by 4 publications

References 15 publications

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF6replacement gas

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF6replacement gas

Measurements of Electron Density and Electron Temperature of Arc Discharge Plasmas Containing Metallic Vapors Using Laser Thomson Scattering

Two-dimensional electron density characterisation of arc interruption phenomenon in current-zero phase

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Product

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Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas

Analysis of the characteristics of DC nozzle arcs in air and guidance for the search of SF₆replacement gas