Puffer-type Gas Circuit Breaker Research Articles

Effects of nozzle shape on the interruption performance of thermal puffer-type gas circuit breakers

During the last decade the advanced interruption techniques, which use the arc energy itself to increase the pressure inside a chamber by PTFE nozzle ablation, have displaced the puffer circuit breakers due to reduced driving forces and better maintainability. In this paper, we have investigated thermal flow characteristics inside a thermal puffer-type gas circuit breaker (GCB) by solving the Navier–Stokes equations coupled with Maxwell's equations for considering all instability effects such as turbulence and Lorentz forces by transient arc plasmas. These relative inexpensive computer simulations might help the engineer researching and designing new advanced interrupters in order to downscale and uprate high-voltage gas-insulated switchgear (GIS) integral.

Effect of Puffer Volume and Operating Force on Dielectric Recovery Performance in Thermal Puffer-Type Gas Circuit Breaker

In order to investigate the influence of puffer volume V/sub P/ and operating force to dielectric performance of GCB at current interruption, we calculated the prospective dielectric withstand voltage V/sub W/ between arcing contacts. The withstand voltage was calculated by the electric field strength appeared on arcing contacts and the allowable electric field strength E/sub W//sup */ of hot gas due to thermal puffer action. We could clarify that large initial puffer volume V/sub P/ can increase withstand voltage V/sub W/ at current breaking point and also that an optimum point exists in operating force F. For example, it was found that in case of the operating force of 1000 kgf, the puffer volume V/sub P/ of 1.2 liter would be best choice in the interrupting condition of i=50 kA and arcing time of 1.35 cycle.

05/00150 Thermo-characterization of power systems components: a tool to diagnose their malfunctions: Zaleta-Aguilar, A. et al. Energy, 2004, 29, (3), 361–377

During the last decade the advanced interruption techniques, which use the arc energy itself to increase the pressure inside a chamber by PTFE nozzle ablation, have displaced the puffer circuit breakers due to reduced driving forces and better maintainability. In this paper, we have investigated thermal flow characteristics inside a thermal puffer-type gas circuit breaker (GCB) by solving the Navier–Stokes equations coupled with Maxwell's equations for considering all instability effects such as turbulence and Lorentz forces by transient arc plasmas. These relative inexpensive computer simulations might help the engineer researching and designing new advanced interrupters in order to downscale and uprate high-voltage gas-insulated switchgear (GIS) integral.

Calculation of Transient Puffer Pressure Rise Takes Mechanical Compression, Nozzle Ablation, and Arc Energy Into Consideration

Thermal puffer-type gas circuit breaker (GCB) has a high dielectric and current interruption capability. In order to design a good thermal puffer GCB, it is important to know the blast pressure for arc cooling. Although pressure calculation programs have been developed and used for design work, the basic characteristics, such as contribution of nozzle ablation gas to puffer pressure rise, amount of back flow gas to puffer chamber, and pressure distribution along gas passages during current interruption, are not well known. In this paper, pressure rise, mass flow, and temperature calculations were carried out using a new calculation model, which takes mechanical compression by puffer piston, nozzle ablation in the nozzle throat and arc energy into consideration. By analysis of the calculation results, we found the pressure rise mechanism is as follows. While fixed contact located in the divergent part of nozzle, all of the ablation gas generated from the nozzle wall cannot be exhausted from the nozzle and it leads to high-pressure generation in the nozzle throat. This pressure causes transfer of hot ablation gas back to the puffer chamber via gas passage. The puffer pressure increases thermally due to temperature rise by this mechanism. At a longer arcing time, as high puffer pressure was already established in the puffer chamber, the nozzle ablation gas cannot flow back to the puffer chamber. Besides as mass flow through nozzle is limited by low gas density, the puffer pressure rise is obtained by the mechanical compression of puffer piston.

Relation between Gas Blast Characteristics and Gas Passage Structure of the Thermal Puffer Type Gas Circuit Breaker

In order to evaluate thermal interruption capability of gas circuit breaker, we consider that mass flow rate in nozzle throat at around current zero points is the most effective parameter, because it is closely related to the cooling capability of arc. In thermal puffer type gas circuit breaker, the mass flow rates depend not only on puffer pressure but also on gas passage structure. So using a calculation program of gas blast characteristics taking both arc energy and ablation gas into consideration, the relations between the mass flow rate at current zero points and gas passage structure were investigated. As the results, we found that shorter gas passage length greatly increases the mass flow rate at current zero points, although it does not influence puffer pressure formation so much. We also found that optimum cross sectional area of gas passage is a bit smaller than that of nozzle throat. If thermal interruption limit were determined by mass flow rate at current zero points, the shorter gas passage length and optimized cross section area will increase the SLF interruption capability of thermal puffer type gas circuit breaker.This paper describes the detail of the results of simulations and discussions.

Computer simulation of phenomena associated with hot gas in puffer-type gas circuit breaker

To analyze hot-gas flow in puffer-type gas circuit breakers (GCBs), a program was developed by adding functions for dealing with opening process, gas compression, and arcing to a program for the analysis of axially symmetric compressive fluids. The accuracy of the program is demonstrated by comparing the results of computation by this program with the results of two different tests: the observation of hot-gas backflows using the Schlieren method and the measurement of breakdown voltage drops resulting from hot gas generated by current interruptions. The results of both tests show trends similar to calculated results obtained by simulating the tests, proving that this program is applicable to interruption phenomena associated with hot gas to a certain extent. The program is applied to the calculation of pressure rise phenomena in a puffer chamber caused by hot-gas backflows and dielectric strength to ground in a tank-type GCB. The program is expected to be useful as a means of estimating test results.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

パッファ式ガス遮断器の電流遮断直後の極間過渡絶縁回復特性

パッファ式ガス遮断器の電流遮断直後の極間過渡絶縁回復特性

Switching Surge of Shunt Reactor Caused by SF6 Circuit Breaker Operation

Using a 300kV puffer-type gas circuit breaker (GCB) combined with a 275kV-150MVA shunt reactor or a test air core reactor at a laboratory, the authors measured surges during reactor current interruption. Such surges as chopping current, single reignition, and multireignition surges were observed. To explain the mechanisms of these surges, the authors measured precisely high-frequency reignition currents with the help of an optical device. Multireignition surges seem unlikely to occur in actual fields.

パッファ式ガスしゃ断器のノズル閉そく現象とそのしゃ断性能に及ぼす影響

パッファ式ガスしゃ断器のノズル閉そく現象とそのしゃ断性能に及ぼす影響

混合ガスを用いたパッファ式ガス遮断器の遮断特性

混合ガスを用いたパッファ式ガス遮断器の遮断特性

Extremely Short Line Fault Tests of a Puffer-Type Gas Circuit Breaker by Direct and Synthetic Test Methods

A series of short line fault tests for extremely short line length were performed at the maximum available direct power in KEMA laboratory, using 245 kV/40 kA puffer-type gas circuit breaker with single interrupter. Synthetic tests were also performed under the approximately same conditions of the direct tests.

Investigation on Gas Flow of Puffer-Type Gas Circuit Breaker Based on Observation of Arc and Pressure Measurement

Energy balance of gas blasted arc was investigated by arc observation, and power loss radially conducted from arc core was evaluated. Based on the experiment, a method which gives better approximation of gas blasted arc was shown.