scholarly journals Comparison of the Interrupting Capability of Gas Circuit Breaker According to SF6, g3, and CO2/O2 Mixture

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6388
Author(s):  
Woo-Young Lee ◽  
Jang-Un Jun ◽  
Ho-Seok Oh ◽  
Jun-Kyu Park ◽  
Yeon-Ho Oh ◽  
...  
Keyword(s):  
Circuit Breaker ◽  
Filling Pressure ◽  
The Other ◽  
Zero Crossing ◽  
Arc Voltage ◽  
Transient Recovery Voltage ◽  
Test Circuit ◽  
Arc Current ◽  
Recovery Voltage ◽  
Current Zero

In the study, an interrupting performance test on the 145 kV gas circuit breaker is performed according to three different gases: SF6, g3 (5% NovecTM4710 with 95% CO2), and CO2(70%)/O2(30%) gases. Thanks to research advancements, it is confirmed that CO2 and g3 (5% NovecTM 4710) gases, respectively, have 40% and 75% dielectric strength, compared to that of SF6 gas. The filling pressure and transient recovery voltage criteria of each gas were determined differently in order to compare the maximum interrupting performance of each gas. The pressure of SF6 gas was determined to be 5.5 bar, which is typically used in circuit breakers. The pressure of the other two gases was determined to be 8.0 bar (the maximum available pressure of the test circuit breaker) to find the maximum interrupting performance. Moreover, the rate-of-rise of transient recovery voltage of SF6 was determined as 10 kV/μs, which is the value at the state of maximum interrupting performance of the test circuit breaker with SF6. On the other hand, the rate-of-rise of transient recovery voltages of g3 (5% NovecTM4710 with 95% CO2) and CO2(70%)/O2(30%) gases were, respectively, determined as 4∼5 kV/μs to find the interruption available point. The characteristics of arc conductance, arc current, and arc voltage near the current zero, and post-arc current are analyzed to compare the interrupting performance, according to different arc-quenching gases. The arc current is measured using a current transformer (Rogowski coil), and a signal processing method of the arc current and arc voltage is introduced to increase the reliability of the interrupting performance results. As a result of the test, it is confirmed that the critical arc conductance for all test conditions converged within a certain range and the value is around 0.7 mS. In addition, the critical current slope just before the current zero-crossing during the interrupting process is shown to be 1.8 A/μs between interruption success and failure. Consequently, it is verified that the CO2(70%)/O2(30%) mixture and g3 (5% NovecTM4710 with 95% CO2) have a similar arc extinguishing performance and SF6 has a relatively higher extinguishing performance than that of CO2(70%)/O2(30%) mixture and g3 (5% NovecTM4710 with 95% CO2) under the aforementioned filling pressure and TRV conditions.

scholarly journals Generate Various Parameters Of Trv Envelope Synthetic Test Circuit

2021 ◽  
Vol 12 (2) ◽  
pp. 1348-1356
Author(s):  
Jagadeesh Peddapudi, Et. al.
Keyword(s):  
High Voltage ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Circuit Breakers ◽  
Force System ◽  
Transient Recovery Voltage ◽  
Test Circuit ◽  
Synthetic Test ◽  
Recovery Voltage ◽  
The Impact

The most basic transient a circuit breaker needs to suffer during its activity is the transient recovery voltage (TRV), started by the electric force system as a characteristic response on flow interference. To test high voltage CBs, direct testing utilizing the force system or short out alternators are not practical. The testing of high voltage Circuit Breakers (CBs) of bigger limit requires huge limit of testing station. An equal infusion of short out current and transient voltage to medium and high voltage circuit breaker (CB) by a synthetic model is examined. Transient recovery voltage is made by a capacitor bank and is applied to CB. An optical set off spark gap has been utilized to interrupt short circuit and to introduce of transient recovery voltage that is applied across the contacts of circuit breaker. Transient recovery voltage examination can never be done totally, as the advancement of circuit breaker development and organization configuration goes on. The most widely recognized way to deal with TRV examination is concerning the supposed planned TRV, in which a suspicion of dismissing association between circuit breaker itself and the innate system recovery voltage is being made. Notwithstanding, it actually is by all accounts qualified to examine what circuit breaker means for transient recovery voltage. An ideal grouping to open/close of reinforcement test article and helper circuit breakers inside suitable chance to infuse of recovery voltage. The impact of reactance of inductive flaw current limiter just as distance to blame in short line issue condition on pace of ascent of recovery voltage. A 4-boundaries TRV synthetic test circuit dependent on equal current infusion technique is planned and mimicked for testing 145kV rating circuit-breakers according to new TRV prerequisites given in IEC 62271-100.

scholarly journals Synthetic Testing of Load Current Interruption in Medium Voltage Load Break Switches

2017 ◽  
Vol 4 (3) ◽  
pp. 241-244
Author(s):  
M. Bendig ◽  
M. Ksoll ◽  
A. Kalter ◽  
M. Schaak ◽  
K. Ermeler ◽  
...  
Keyword(s):  
Load Current ◽  
Power Sources ◽  
Power Generator ◽  
Medium Voltage ◽  
Current Test ◽  
Transient Recovery Voltage ◽  
Test Circuit ◽  
Synthetic Test ◽  
Recovery Voltage ◽  
Current Zero

To conduct the mainly active load current test duty according to IEC 62271-103, a directly powered test circuit and therefore a medium voltage connection or a power generator is needed. A newly developed synthetic test circuit allows to replicate the current as well as the full transient recovery voltage (TRV) and the power frequent recovery voltage (RV) of the direct test circuit up to its crest value. It is dimensioned for voltage classes up to 52 kV and can be adapted to test currents between 630 A and 1250 A. The test circuit allows a detailed investigation of load break switches without costly high power sources and loads. Many parameters, like current and voltage steepness at current zero, as well as different parameters defining the TRV steepness can be varied individually.

Current Zero at Prospective Transient Recovery Voltage Measurement

2016 ◽  
Vol 136 (2) ◽  
pp. 170-174 ◽  
Author(s):  
Tadashi Koshizuka ◽  
Yasuhiko Taniguchi ◽  
Eiichi Haginomori ◽  
Hisatoshi Ikeda ◽  
Keisuke Udagawa
Keyword(s):  
Voltage Measurement ◽  
Transient Recovery Voltage ◽  
Recovery Voltage ◽  
Current Zero

Computations on the Thermal Characteristics of SF6 and CO2 Switching Arcs on a Microscopic Scale

2020 ◽  
Vol 20 (11) ◽  
pp. 7201-7205
Author(s):  
Youn-Jea Kim ◽  
Jong-Chul Lee
Keyword(s):  
Greenhouse Gases ◽  
Sulfur Hexafluoride ◽  
Thermal Characteristics ◽  
Dielectric Medium ◽  
Point Of View ◽  
Microscopic Scale ◽  
Transient Recovery Voltage ◽  
Complete Work ◽  
Recovery Voltage ◽  
Current Zero

Pure sulfur hexafluoride is a colorless, odorless, non-toxic, inflammable, chemically inert and thermally stable gas and has proven its worth as an excellent interruption and dielectric medium. SF6 has been successfully used for interruption and insulation purposes as interrupters and circuit-breakers in gas-insulated substations. Due to its long lifetime and high global warming potential, this gas was put on the list of fluorinated greenhouse gases in the Kyoto Protocol aimed at controlling the emission of man-made greenhouse gases. This factor makes the search for an environmentally friendly alternative to SF6 all the more urgent. In this paper, we conducted computations on the thermal and aerodynamic behaviors of SF6 and an alternative CO2 switching arcs in a self-blast chamber in order to compare the switching phenomena and the thermal reignition from an engineering point of view. Through the complete work, the 3,000 K isotherm of the remnant arc column within microseconds after a current zero was used to evaluate the thermal reignition of SF6 and CO2 switching arcs with the slope of the tangential line of the transient recovery voltage on a microscopic scale.

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