scholarly journals Post-Arc Characteristics of High-Current Arcs in Vacuum Circuit-Breakers

2019 ◽  
Vol 6 (2) ◽  
pp. 170-174
Author(s):  
N. Wenzel ◽  
W. Haas
Keyword(s):  
Short Circuit ◽  
Early Period ◽  
Metal Vapor ◽  
Transverse Magnetic ◽  
High Current ◽  
Electric Resistance ◽  
Circuit Breakers ◽  
Arc Characteristics ◽  
Current Zero ◽  
Short Circuit Currents

The post-arc (PA) characteristics of vacuum arcs in transverse magnetic field contacts are studied for short-circuit currents of up to 123 kA peak and transient recovery voltages below 875 V. The measured PA currents are interpreted in terms of an Electric Resistance Model and the models of Andrews-Varey, Langmuir-Child, and Slepian-Schmelzle. Whereas in the late PA period, the calculations do not agree well with the measurements, the PA behavior is well described in the early period after current-zero. It is concluded that the PA discharge is amplified by ionization of metal vapor particles in the boundary sheath due to electron impact.

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.

Study of Generator Source Short-Circuit Currents with Respect to Interrupting the Duty of Generator Circuit Breakers, EMTP Simulation, ANSI/IEEE and IEC Methods

2008 ◽  
Vol 9 (3) ◽  
Author(s):  
J. C Das
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Circuit Breakers ◽  
Time Constants ◽  
Method Of Calculation ◽  
Generator Circuit ◽  
Dc Component ◽  
Current Zero ◽  
Short Circuit Currents ◽  
A Current

Large generators have high effective X/R ratios and combined with other generator time constants and parameters, a current zero may not be obtained at the time of contact parting, i.e., the dc component of the short-circuit current at the contact parting time is higher than the peak ac component. This is well documented in the current literature. The paper presents calculations of the generator source short-circuit currents of a 234 MVA generator using ANSI/IEEE and IEC standards and EMTP simulation. The results are compared and the application of a generator breaker to meet the requirements of calculated duties are discussed. It shows considerable differences in the results, depending upon the method of calculation.

scholarly journals Development of a Method and Algorithm for Inhibiting an Automatic Transfer Switch of the Circuit Breaker for a Sustained Short-Circuit

2020 ◽  
Vol 220 ◽  
pp. 01011
Author(s):  
Igor Nikolaevich Fomin ◽  
Roman Pavlovich Belikov ◽  
Tatyana Anatolyevna Kudinova ◽  
Nailya Kamilevna Miftakhova
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Electrical Equipment ◽  
Ring Network ◽  
Circuit Breakers ◽  
Emergency Situations ◽  
Short Circuit Currents

Circuit breakers with automatic transfer switches (ATS) are designed in such a way that when the voltage disappears during a short-circuit (SC) in the ring network line, the ATS device is triggered. At the same time, its switch is turned on at short-circuit, then it is turned off with acceleration. Even a shortterm switching on of the automatic transfer switch for a sustained short-circuit leads to emergency situations [1,2]. The electrical equipment of the ring network spare line is exposed to high emergency short-circuit currents, and the consumers powered by the spare transformer are turned off. It is possible to minimize and eliminate the damages caused by the above mentioned cases by inhibiting the switching on of the circuitbreaker of the automatic transfer switch.

scholarly journals Emission Spectroscopy During High-Current Anode Modes in Vacuum Arc

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.

scholarly journals Arcing Behaviors in the Large-capacity HV SF6 Gas-blast Interrupters

2019 ◽  
Vol 6 (2) ◽  
pp. 140-143 ◽  
Author(s):  
S. A. Averyanova ◽  
E. Tonkonogov
Keyword(s):  
High Voltage ◽  
Short Circuit ◽  
Dielectric Strength ◽  
Numerical Results ◽  
Circuit Breakers ◽  
Large Capacity ◽  
Recovery Processes ◽  
Strength Recovery ◽  
Turbulence Effects ◽  
Short Circuit Currents

A comprehension of the dielectric strength recovery processes during the interruption of short-circuit currents in the high-voltage SF<sub>6</sub> gas-blast circuit breakers is necessary for their modernisation in order to increase the rated voltage and short circuit breaking current per one break. This paper presents numerical results of the turbulence effects on the interruption ability in the SF<sub>6</sub> extinguishing arc chamber.

Investigation of dependences of selectivity of devices of protection against the value of short circuit currents in electrical networks up to 1000 V

2021 ◽  
pp. 98-100
Author(s):  
I. Radko ◽  
◽  
V. Nalivayko ◽  
O. Okushko ◽  
I. Bolbot ◽  
...  
Keyword(s):  
Single Phase ◽  
Modular Design ◽  
Short Circuit ◽  
Electrical Network ◽  
Electrical Networks ◽  
Circuit Breakers ◽  
New Energy ◽  
Short Circuits ◽  
Pole Scheme ◽  
Short Circuit Currents

According to PUE-2017, each group line must be protected against short circuits. Instant disconnection (cut-off) of the line in the event of short circuits provides an electromagnetic release of the circuit breaker. Reliable tripping is possible if the current of a single-phase short circuit is greater than the instantaneous tripping current. Today on the market are widely available circuit breakers with characteristics "B", "C" and "D", which are characterized by different multiplicities of the cut-off current of the electromagnetic release. Some European companies produce circuit breakers with other characteristics, which greatly expands the possibilities protection of electrical equipment. The difficulty in organizing the selectivity of protection is that the circuit breakers of modular design when switching off short circuits are characterized by the same switching time (not more than 0.05 s). The purpose of the research is to find ways to organize the selectivity of protection in electrical networks with voltage up to 1000 V using reliable values of short-circuit currents. In networks with a voltage of up to 1000 V, the current of a single-phase short circuit can be calculated fairly accurately if the exact values of all sections of the electrical network are known. In practice, it is not always possible to obtain reliable data on the numerical characteristics of the 0.4 kV network to which a new energy facility is connected. Therefore, it is proposed to consider part of the network as an active quadrupole, the characteristics of which are obtained by measurements at the point of connection. For further calculations it is necessary to know the voltage at the clamps of the four-pole scheme and the internal impedance. Based on the theory of four-pole scheme, you can get the original data for calculations without calculating the internal parameters of four-poles scheme. Thus, it is proposed to use a hybrid method for estimating the magnitude of probable short-circuit currents in electrical networks up to 1000 V when designing new energy facilities. Credible values of short-circuit currents will allow to organize selective protection of electric networks.

SWITCHING AND LIGHTNING OVERVOLTAGES AND THE REQUIRED WITHSTAND VOLTAGE BETWEEEN THE OPEN CONTACTS OF 245 KV CIRCUIT BREAKERS

2016 ◽  
Vol 63 (0) ◽  
pp. 43-60 ◽  
Author(s):  
Janusz BANDEL ◽  
Artur HEJDUK ◽  
Andrzej DZIERŻYŃSKI ◽  
Piotr KORYCKI ◽  
Henryk SIBILSKI
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Dielectric Strength ◽  
Electrical Insulation ◽  
Power Engineering ◽  
Circuit Breakers ◽  
Short Circuit Currents ◽  
Very High ◽  
Single Break

This paper deals with the surges generated in the network during switching operations and lightning surges. The level of both kinds of surge was compared with the required dielectric strength between the open contacts of 245 kV circuit breakers. Overvoltages greater than the electrical withstand voltage of the circuit breaker can cause arc ignition between the circuit breaker’s open contacts and power engineering service s have reported such cases. The results of such failures can be very serious. This is a problem especially for single-break circuit breakers, in which the stresses on the electrical insulation between the open contacts of the breaker are very high. A method for selecting lightning arresters to lower the overvoltages is proposed. The switching of short-circuit currents by a circuit breaker may cause a weakening of the circuit breaker chamber’s insulation and reduce its electrical withstand and durability.

scholarly journals О способе увеличения предельно допустимого уровня ударных токов короткого замыкания в электрических контактах

2019 ◽  
Vol 89 (4) ◽  
pp. 614
Author(s):  
А.М. Чалый ◽  
В.А. Дмитриев ◽  
М.А. Павлейно ◽  
О.М. Павлейно ◽  
М.С. Сафонов
Keyword(s):  
Heat Release ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Electrical Contacts ◽  
Recrystallization Temperature ◽  
High Current ◽  
Maximum Permissible Level ◽  
Impulsive Heating ◽  
Pass Through ◽  
Short Circuit Currents

AbstractCurrent passing through electrical contacts causes additional heat release due to the presence of a contact resistance. Heat release in contacts may be considerable. In high-current contacts of high-voltage electrical equipment, the problem of overheating gets worse when fault short-circuit currents pass through the contacts. The maximum permissible level of these currents is limited by heating contact areas to their melting point. Welds due to melting of contacts lead to their failure as a rule. A way of considerably raising maximum permissible short-circuit currents has been suggested. Its idea is impulsive preheating of contacts to a temperature higher than the recrystallization temperature of the contact material. The efficiency of this approach has been confirmed experimentally. Numerical simulation of impulsive heating has been conducted. The results have helped us elaborate recommendations for selecting parameters of a train of current pulses that, acting on a contact, may greatly improve its stability against short-circuit currents.

Sign in / Sign up

Export Citation Format

Share Document