Dead Tank Circuit Breaker Research Articles

Fluid Dynamics Calculation in SF6 Circuit Breaker during Breaking as a Prerequisite for the Digital Twin Creation

The requirements to switching the capacities of SF6 circuit breakers submitted by Russian Grid companies are difficult to satisfy. The first limitation is related to material and financial costs in order to create a new requirement-satisfying switching device. The second limitation is dictated by the necessity of calculating complex physical processes in a circuit braker interrupter during fault–current making or breaking before creating a prototype. The latter task is reduced to the problem of simulating the processes of interaction between the switching arc and the SF6 gas flow. This paper deals with the solution of the problem both analytically by a special method and numerically by a numerical software package through the creation of a mathematical model of the interaction process. The switching arc is taken into account as a form of a temperature source, based on experimental data on measuring the temperature of the arc column. The key feature of the research is to use the finite element method based on a moving mesh—the Arbitrary Lagrangian Eulerian (ALE) method. Such a problem statement allows us to take the contact separation curve of the circuit breaker into account as the input data of the model. The calculations were carried out during fault-current breaking by a 110 kV SF6 dead-tank circuit breaker. The calculations of pressure and mass flow in the under-piston volume change, gas flow speed, and temperature depending on the contact separation are given. The proposed model of the switching arc was used to simulate the process of 25 kA symmetrical fault–current breaking and was compared with an experiment.

Density monitoring of high-voltage SF<sub>6</sub> circuit breakers

Circuit breakers play a vital role in ensuring the stability and reliability of a power system [1]. When a circuit breaker operates, the contacts inside the circuit breaker open and the electrical arc is extinguished resulting in the electrical circuit being interrupted [2]. Circuit breakers are named by the medium that is used to extinguish the electrical arc, with the most common type being sulfur hexafluoride (SF6) circuit breakers [3]. Figure 1 shows a typical design of a 132-kV live tank and dead tank circuit breaker.

Effects of Hot>tex<$rm SF_6$>/tex<on Post-Arc Circuit Breaker Design

SF/sub 6/ is blown through the arc during interruption of an SF/sub 6/ puffer circuit breaker. This hot gas flows down an exhaust tube into the chamber of a dead tank circuit breaker where it can lower the dielectric withstand between the exhaust tube and the tank of the circuit breaker, leading to dielectric breakdown during the transient recovery voltage after clearing. This paper presents experimental evidence that any such breakdown is controlled by the hot gas near the exhaust tube, with cold gas in the remainder of gap having little effect on the breakdown voltage. This experimental conclusion is supported by a detailed theory for conditions under which breakdown can occur.

Application of 800-kV SF6 dead tank circuit breaker with transmission line surge arrester to control switching transient overvoltages

An 800-kV metal oxide transmission line surge arrester (TLA) has been developed, installed and tested on the AEP 765-kV Marysville-Kammer transmission line. The purpose of this TLA is to pave the way for the development, construction and application of an 800-kV SF/sub 6/ dead tank circuit breaker without closing resistors and free standing current transformers at American Electric Power's (AEP) 800-kV Orange station. Eight hundred kilovolts is the maximum design operating voltage, and 765 kV is the nominal operating voltage. Successful field test results of the TLAs ability to limit switching overvoltages emanating from circuit breaker operation to below the transmission line switching withstand are given. In addition, successful test results of the 800-kV dead tank circuit breaker design dielectric test are given in this paper.

Application of 800 kV SF6 Dead Tank Circuit Breaker with Transmission Line Surge Arrester to Control Switching Transient

An 800 kV metal oxide transmission line surge arrester (TLA) has been developed, installed, and tested on the AEP 765 kV Marysville to Kammer transmission line. The purpose of this transmission line surge arrester (TLA) is to pave the way for the development, construction, and application of an 800 kV SF6 dead tank circuit breaker without closing resistors and free standing current transformers at AEP's 800 kV Orange station. The maximum design operating voltage is 800 kV, and 765 kV is the nominal operating voltage. Successful field test results of the TLA's ability to limit switching overvoltage emanating from circuit breaker operation to below the transmission line switching withstand are given. Successful test results of the 800 kV dead tank circuit breaker design dielectric test are given.

Dead Tank Circuit Breaker Design Techniques

A new dead tank circuit breaker has been developed with the manufacturing and testing advantages of the modular live tank circuit breaker concept. By locating the puffer interrupter inside the porcelain bushing it is possible to reduce the size of the single-phase breaker tank to the minimum required to support and insulate the main conductor and locate the circuit breaker bushings. Only one supporting insulator is used inside the tank for all the breaker components, and only one insulating operating rod bridges the gap from the tank to the main conductor. The rest of the insulation to earth is in gas and self-restoring.

Dead Tank Circuit Breaker Design Techniques

A new dead tank circuit breaker has been developed with the manufacturing and testing advantages of the modular live tank circuit breaker concept. By locating the puffer interrupter inside the porcelain bushing it is possible to reduce the size of the single-phase breaker tank to the minimum required to support and insulate the main conductor and locate the circuit breaker bushings. Only one supporting insulator is used inside the tank for all the breaker components, and only one insulating operating rod bridges the gap from the tank to the main conductor. The rest of the insulation to earth is in gas and self-restoring.

A New Compressed-Air Dead-Tank Circuit Breaker for Interrupting 10,000,000 Kva at 138 Kv

MEMBERAIEE M ETROPOLITANareas suchasNew m YorkCity,Philadelphia, Pittsburgh, Detroit, Chicago, andNewark, etc., present theii ownpeculiar problems incircuit-breaker application. Powerconcentiations inthese areas continue togrow rapidly. Powerformanysections within these areas mustbetransmitted through underground cables, andprevious transmission voltages fortheseandother sections nolonger areeconomical forthe loads involved. Atpresent, 138kvwill meetrequirements, tboughifpresent growthrates continue, thefuture may makethis toolow.A circuit breaker for 138kv therefore isindicated. Load growtb factors determine thattheshortcircuit interrupting capacity ofthese breakers should be10,000,000 kvaforthe foreseeable future. In addition tothesefactors, local ordinances andinsurance regulations are unfavorable totheuseoftheconventional oilcircuit breaker. Further, thecostof oilstorage spaceandhandling forsuch locations requires thatareconsideration begiven tothetypeofcircuit breaker to bespecified. The useof compressed-air circuit breakers isnotnewevenfortheconditions indicated. However, previous designs havenotretained certain desirable features oftheoilcircuit breaker which havebeenconsidered almostnecessary partsofthecircuit breaker by the American user.Two ofthesefeatures aretheprovision formounting bushingtypecurrent transformers andtheuseof potential devices onthebreaker actuated byvoltage tapstotheentrance bushings.