scholarly journals Mechanisms Responsible for Arc Cooling in Different Gases in Turbulent Nozzle Flow

2017 ◽  
Vol 4 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Y. Guo ◽  
H. Zhang ◽  
Y. Yao ◽  
Q. Zhang ◽  
J. D. Yan
Keyword(s):  
Material Properties ◽  
High Speed ◽  
Gas Flow ◽  
Ohmic Heating ◽  
Circuit Breaker ◽  
Fault Current ◽  
High Current ◽  
Physical Mechanisms ◽  
Current Zero ◽  
Different Gases

A high voltage gas blast circuit breaker relies on the high speed gas flow in a nozzle to remove the energy due to Ohmic heating at high current and to provide strong arc cooling during the current zero period to interrupt a fault current. The physical mechanisms that are responsible for the hugely different arc cooling capabilities of two gases (SF<sub>6</sub> and air) are studied in the present work and important gas material properties controlling the cooling strength identified.

scholarly journals Investigation and Numerical Simulation of a High-Current AC Circuit Breaker

2019 ◽  
Vol 6 (3) ◽  
pp. 235-238
Author(s):  
I. Murashov ◽  
V. Frolov ◽  
A. Kvashnin ◽  
J. Valenta ◽  
D. Simek ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
High Speed ◽  
Circuit Breaker ◽  
Moving Mesh ◽  
Electrical Characteristics ◽  
High Current ◽  
Spectral Diagnostics ◽  
Current Voltage ◽  
Time Calculation

The article is devoted to the study of the high-current AC circuit breaker. The results of the study are presented for various configurations of the arc divider. The study includes methods of spectral diagnostics and high-speed camera shooting synchronized with the electrical characteristics of the circuit breaker (current, voltage) in time. The obtained results allow to determine the composition of the plasma and dynamics of changes in the composition of the discharge in time. Calculation of the plasma composition and properties is made according to the obtained data, which makes it possible to take into account the products of circuit breaker materials ablation in numerical simulation. Non-stationary two-dimensional mathematical model with a moving mesh is developed. The obtained results allow to correct and verify the developed mathematical model of the circuit breaker operation. The evaluation of the arc divider influence is presented in the article.

scholarly journals Ablation-Dominated Arcs in CO2 Atmosphere - Part II: Molecule Emission and Absorption

2020 ◽  
Author(s):  
Ralf Methling ◽  
Nicolas Götte ◽  
Dirk Uhrlandt
Keyword(s):  
Absorption Spectroscopy ◽  
High Speed ◽  
Broad Band ◽  
Imaging Spectroscopy ◽  
Circuit Breaker ◽  
Visible Spectral Range ◽  
Nozzle Geometry ◽  
Ambient Conditions ◽  
Band Absorption ◽  
Current Zero

Molecule radiation can be used as a tool to study colder regions in switching arc plasmas like arc fringes in contact to walls and ranges around current zero (CZ). This is demonstrated in the present study for the first time for the case of ablation-dominated high&ndash;current arcs as key elements of self&ndash;blast circuit breakers. The arc in a model circuit breaker (MCB) in CO2 with and an arc in a long nozzle under ambient conditions with peak currents between 5 and 10 kA were studied by emission and absorption spectroscopy in the visible spectral range. The nozzle material was polytetrafluoroethylene (PTFE) in both cases. Imaging spectroscopy was carried out either with high-speed cameras or with intensified CCD cameras. A pulsed high-intensity Xe lamp was applied as background radiator for the broad-band absorption spectroscopy. Emission of Swan bands from carbon dimers was observed at the edge of nozzles only or across the whole nozzle radius with highest intensity in the arc center, depending on current and nozzle geometry. Furthermore, absorption of C2 Swan bands and CuF bands were found with the arc plasma serving as background radiator. After CZ, only CuF was detected in absorption experiments.

scholarly journals Influence of Varying Gaps Between TMF Contacts on Constricted High Current Vacuum Arcs

2019 ◽  
Vol 6 (1) ◽  
pp. 103-106
Author(s):  
B. Kühn ◽  
B. Weber ◽  
D. Gentsch ◽  
M. Kurrat
Keyword(s):  
High Speed ◽  
Industrial Development ◽  
Circuit Breaker ◽  
Metal Vapor ◽  
High Speed Camera ◽  
High Current ◽  
Medium Voltage ◽  
Vacuum Circuit Breaker ◽  
Vacuum Test ◽  
Transversal Magnetic

The behavior of high current arcs in vacuum circuit breaker (VCB) is interesting for research and industrial development purpose which lead to further products. To improve the interruption capability of VCB, two approaches to control the arc have been proven successful. Applying transversal magnetic fields (TMF) on the arc is use for industrial VCB in medium voltage ranges. For greater gap distances the behavior of the arc is less thoroughly investigated. <br /> In this paper, the appearance of metal vapor arcs drawn by common TMF contacts in a vacuum-test-interrupter is investigated. An adapted drive mechanism enables to interrupt a fixed current with varying gaps from 5 to 25 mm and a constant opening time. Breaking operations with a 50 Hz current are observed with a high speed camera. With increasing gap distance a changed arc appearance can be observed. The goals of this work are to be understood as a feasibility study for optical evaluation methods for vacuum arcs under TMF.

scholarly journals Analysis of C2 Swan Bands in Ablation-Dominated Arcs in CO2 Atmosphere

2019 ◽  
Vol 6 (1) ◽  
pp. 82-86
Author(s):  
R. Methling ◽  
St. Franke ◽  
N. Götte ◽  
S. Wetzeler ◽  
D. Uhrlandt
Keyword(s):  
High Speed ◽  
Circuit Breaker ◽  
Optical Emission ◽  
Active Phase ◽  
Video Camera ◽  
Nozzle Geometry ◽  
Optical Absorption Spectroscopy ◽  
Iccd Camera ◽  
Copper Electrodes ◽  
Current Zero

A model circuit breaker in a high-pressure chamber filled with CO<sub>2</sub> atmosphere is used to operate a wall-stabilized arc of several kilo-amperes between tungsten-copper electrodes surrounded by polytetrafluoroethylene nozzles. Optical emission spectroscopy (OES) is carried out via quartz plates inserted into the nozzles using a combination of an imaging spectrometer either with a high-speed video camera or with an ICCD camera. Depending on the nozzle geometry and the current, continuum from C<sub>2</sub> Swan bands was detected as absorption as well as emission pattern. After current zero, optical absorption spectroscopy (OAS) using a xenon flashlamp as broadband background radiator was applied. An absorption around 493 nm was detected and attributed to CuF molecules. The study proofs the existence of C<sub>2</sub> in the active phase and the formation of CuF near to current zero.

Study of anode spot transient processes of a high-current vacuum arc with high-speed spectroscopy and videorecording

2021 ◽  
Vol 64 (1) ◽  
pp. 112-117
Author(s):  
A.V. Schneider ◽  
◽  
S.A. Popov ◽  
E.L. Dubrovskaya ◽  
A.Y. Yushkov ◽  
...  
Keyword(s):  
High Speed ◽  
Arc Discharge ◽  
Circuit Breaker ◽  
Vacuum Arc ◽  
Charge Composition ◽  
High Current ◽  
Anode Region ◽  
Anode Spot ◽  
Vacuum Circuit Breaker ◽  
Switching Characteristics

The processes of plasma formation in the anode region of a high-current vacuum arc discharge are of high actuality in terms of improving the switching characteristics of vacuum circuit breaker. In present paper the dynamics of the radiation spectrum of anode region was recorded with the system that allows time scanning of a spectrum. In parallel, there was high-speed videorecording. The obtained data clearly show changes in the charge composition of the anode spot plasma in the process of changing discharge forms.

scholarly journals Ablation-Dominated Arcs in CO2 Atmosphere—Part II: Molecule Emission and Absorption

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4720
Author(s):  
Ralf Methling ◽  
Nicolas Götte ◽  
Dirk Uhrlandt
Keyword(s):  
Absorption Spectroscopy ◽  
High Speed ◽  
Broad Band ◽  
Imaging Spectroscopy ◽  
Circuit Breaker ◽  
Visible Spectral Range ◽  
Nozzle Geometry ◽  
Ambient Conditions ◽  
Band Absorption ◽  
Current Zero

Molecule radiation can be used as a tool to study colder regions in switching arc plasmas like arc fringes in contact to walls and ranges around current zero (CZ). This is demonstrated in the present study for the first time for the case of ablation-dominated high-current arcs as key elements of self-blast circuit breakers. The arc in a model circuit breaker (MCB) in CO2 with and an arc in a long nozzle under ambient conditions with peak currents between 5 and 10 kA were studied by emission and absorption spectroscopy in the visible spectral range. The nozzle material was polytetrafluoroethylene (PTFE) in both cases. Imaging spectroscopy was carried out either with high-speed cameras or with intensified CCD cameras. A pulsed high-intensity Xe lamp was applied as a background radiator for the broad-band absorption spectroscopy. Emission of Swan bands from carbon dimers was observed at the edge of nozzles only or across the whole nozzle radius with highest intensity in the arc center, depending on current and nozzle geometry. Furthermore, absorption of C2 Swan bands and CuF bands were found with the arc plasma serving as background radiator. After CZ, only CuF was detected in absorption experiments.

Sign in / Sign up

Export Citation Format

Share Document