Properties of Vacuum Arc Influenced by Electrode Diameter and Material in TMF Contact Based on Forced Current Zero

With the increase in electrical equipment in More/All Electric Aircraft, 270 V dc power supply systems will be needed. One method for DC interruption is forced current zero (FCZ). Based on FCZ technology with transverse-magnetic-field (TMF) contact, the spiral-type contacts are designed. Experiments with different currents are carried out with contact diameters being 30 mm, 40 mm, and 50 mm, and arcing surface materials Cu-W80 alloy and Cu-Cr50 alloy respectively. It is indicated by the experimental results that breaking capacity of vacuum interrupter and vacuum arc appearance are closely related to the electrode diameter and material. For the same size of electrode diameter, the breaking capacity in Cu-Cr50 is better than that in Cu-W80. With increasing electrode diameter, arc column expansion velocity and diameter increase gradually. Breaking capacity is increasing with larger contact diameter.

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Emission Spectroscopy During High-Current Anode Modes in Vacuum Arc

Plasma Physics and Technology Journal ◽

10.14311/ppt.2017.3.249 ◽

2017 ◽

Vol 4 (3) ◽

pp. 249-252

Author(s):

A. Khakpour ◽

R. Methling ◽

St. Franke ◽

S. Gortschakow ◽

D. Uhrlandt

Keyword(s):

Emission Spectroscopy ◽

Optical Emission ◽

Metal Vapor ◽

Vacuum Arc ◽

Anode Surface ◽

High Current ◽

Temporal And Spatial Distribution ◽

Vacuum Interrupter ◽

Ionic Copper ◽

Current Zero

A vacuum interrupter reaches its interruption limit once high-current anode phenomena occur. High-current anode modes lead to an increase of the anode surface temperature and an increased generation of metal vapor, which may result in a weakening of the dielectric recovery strength after current zero. In this work, different discharge modes in a vacuum arc for AC 50 Hz including diffuse, footpoint, anode spot type 1 and type 2, and anode plume are investigated. Electrodes made of CuCr7525 with diameter of 10 mm are used. The final gap length is about 20 mm. Time and space resolved optical emission spectroscopy is used to examine the temporal and spatial distribution of atomic and ionic copper lines. The distribution of atomic and ionic lines parallel and perpendicular to the anode surface is investigated. Radiator density is also determined for CuI, CuII, and CuIII near the anode surface.

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DC Current Interruption Based on Vacuum Arc Impacted by Ultra-Fast Transverse Magnetic Field

Energies ◽

10.3390/en13184644 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4644

Author(s):

Ehsan Hashemi ◽

Kaveh Niayesh

Keyword(s):

Magnetic Field ◽

Transverse Magnetic Field ◽

Transverse Magnetic ◽

Vacuum Arc ◽

Zero Crossing ◽

Vacuum Interrupter ◽

Novel Approach ◽

Element Simulation ◽

Arc Current ◽

Dc Current

In this paper, the effect of an external ultrafast transverse magnetic field (UFTMF) on a vacuum arc in the diffused mode has been studied. According to the results of studies, a novel approach for making a zero-crossing in a DC arc current has been presented. Plasma voltage fluctuations of the vacuum arc, which are caused by UFTMF, have been investigated via finite element simulation and two-fluid description of plasma physics. By making an appropriate UFTMF through an external circuit, the arc current can be commuted successfully from the vacuum interrupter (VI) to a parallel capacitor and charge it up. In this way, a zero-crossing in the arc current can be achieved, and the current will be interrupted by the VI. Simulation results, which are supporting physical backgrounds for this analysis, have been presented in this paper while technological issues for industrial implementation of this concept have been discussed in detail.

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