scholarly journals Novel DC current interruption technology based on the instability of vacuum arc under composite transverse magnetic fields

2021 ◽  
Author(s):  
Shaowei Liu ◽  
Hui Ma ◽  
Jinlong Chen ◽  
Yingsan Geng ◽  
Zhiyuan Liu ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Transverse Magnetic ◽  
Vacuum Arc ◽  
Current Interruption ◽  
Dc Current

scholarly journals Rotating Constricted Switching Arcs Burning in Gas and in Vacuum

2017 ◽  
Vol 4 (2) ◽  
pp. 173-176
Author(s):  
D. Baron ◽  
S. Ettingshausen ◽  
M. Koletzko ◽  
A. Lawall ◽  
T. Rettenmaier ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
High Velocity ◽  
Scaling Law ◽  
Metal Vapor ◽  
Transverse Magnetic ◽  
High Current ◽  
Circuit Breakers ◽  
Current Interruption ◽  
Magnetic Probes ◽  
Contact Size

The method of controlling high-current switching arcs by transverse magnetic fields (TMF) forcing the constricted arc to rotate in a contact system is being applied successfully to improve the breaking capability of vacuum interrupters and gas circuit breakers. We describe the behavior of magnetically driven switching arcs in vacuum and in gas environment. We report on experiments using high-velocity videography, magnetic probes, and spectroscopy; they deliver the velocity, the temperature and the voltage of an arc. We present models and simulations of the moving constricted arc burning in metal vapor and in air. And we describe a particular switching application of TMF arc control and explain a scaling law of the contact size with the current interruption capability.

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

Energies ◽  
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.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

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