• KIEE International Transactions on Electrophysics and Applications
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• 제5C권4호
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• pp.145-151
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• 2005

The synthetic breaking test method was developed to evaluate the breaking performance of ultra high-voltage circuit breaker and made up of two independent circuits; current source circuit and voltage source circuit. In application of this test method, it is necessary to extend the arc of the test breaker. So, the new re-ignition system using VTGS (Vacuum Triggered Gap-Switch) was constructed to improve the efficiency and reliability of this test. In this re-ignition system, VTGS operates in high vacuum state of $5{\time}10^{17}$torr and control system consists of the triggering device and the air M-G (Motor-Generator). This re-ignition system showed the operating characteristics, such as delay time ($t_d$) and jitter time ($t_j$ not exceeding 5us and 1us respectively, and had the operating voltage of $25\~150kVdc$ at the gap distance of 24mm.

• 한국전기전자재료학회논문지
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• 제34권1호
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• pp.50-55
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• 2021

Copper-chromium alloys have been used as contact materials of vacuum interrupters in circuit breakers, but new materials with highly stable performance are required to break the high voltage and high current barrier due to the recent increase in breaking capacity. In this paper, a new contact material was fabricated from a ternary alloy instead of existing Cu-Cr alloys. Its breaking performance and endurance were verified from a synthetic test and compared with that of various contact materials. The test results verified that the breaking performance of the new contact material was excellent.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.881-885
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• 2018

In order to develop a gas circuit breaker (GCB), the breaking performance of the short line fault (SLF) should be prioritized over that of the breaker terminal fault (BTF). In brief, it is necessary to evaluate the thermal characteristics of the insulating gas that is filled in a GCB. In the process of developing a GCB, many companies use the simplified synthetic testing facility (SSTF).In order to evaluate the SLF breaking performance of a GCB with a long minimum arcing time, a modifications to the conventional SSTF was proposed. In this study, we developed the SSTF with a modified transient recovery voltage circuit. The performance of the newly developed SSTF was verified by an $L_{90}$ breaking performance test on a rating combination of 170 kV, 50 kA, and 60 Hz.

• 전기학회논문지
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• 제59권2호
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• pp.328-332
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• 2010

The SLF(Short Line Fault) breaking capability test for high voltage class $SF_6$ GCB(Gas Circuit Breaker) was conducted. Simplified LC resonant circuit test facility was used for SLF breaking test. During test, Test current was measured by Rogwski coil and arc voltage was measured by voltage divider. Arc conductance was calculated by using these test results before 200ns at current zero. Critical arc conductance value at rated voltage 145kV class is about 2.3mS regardless of breaking current magnitude and arc conductance value at rated voltage 170kV class is about 2.6mS.

• 전기학회논문지
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• 제56권9호
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• pp.1566-1570
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• 2007

[ $SF_6$ ] gas circuit breakers are widely used for short circuit current interruption in EHV(Extra High Voltage) or UHV(Ultra High Voltage) power systems. To develop $SF_6$ gas circuit breakers, the arc resistance value is necessary to compare experimental results to numerical ones. The arc resistance value can be obtained from a breaking test with a $SF_6$ gas circuit breaker. The direct testing or synthetic testing facility is widely used to verify the breaking ability for $SF_6$ gas circuit breakers. We employed the simplified synthetic testing facility to test a $SF_6$ gas circuit breaker prototype. The arc resistance characteristic was measured and calculated under the various experimental conditions. This arc resistance value can be used for verifying the numerical results from arc simulation in a circuit breakers.

• 대한전기학회논문지:전력기술부문A
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• 제50권6호
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• pp.287-292
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• 2001

This paper deals with the configuration, operating principles, systematic calculation method of parameter and optimization method of test circuit for parallel current injection method, series voltage injection method and hybrid synthetic test method as the method for performance test of circuit breaker with extra high interrupting capacity. The test method depicted above is applied to short-circuit making and breaking test (operating sequence :Os CdOs, Od-CdOs) and out-of-phase tests(operating sequence :Os, CdOs) for performance test of the newly-developed 420kV, 50kA and 800kV 50kV puffer-type gas circuit-breaker according to IEC 60056 and IEC 60427. The testing results, evaluation of equivalence for test and analyzed results are also presented in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.554-556
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• 2004

Testing capacity of KERI synthetic short-circuit testing facilities has been upgraded to fulfill the requirements up to 550kV 63kA, 1-break circuit breaker ratings. Specially the current capacity was increased 50kA to 63kA and the full type test of 362kV 63kA circuit breaker(1-break) was firstly completed in domestic. UP to now, domestic manufacturers have depended on the foreign testing laboratory for performance verification of newly designed products. This paper introduces the summary of the increased short-circuit testing facilities, the testing techniques and its results for the making and breaking performance of 362kV, 63kA circuit breaker which was Performed according to IEEE C37.06(1999) used in North America.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.569-571
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• 2005

In case of dead-tank circuit breaker with the earthed enclosure, the dielectric performance for phase to ground should be verified under the hot-gas condition produced by the current interruption. This test condition is required in breaking test duties with the rated short-circuit current and rated voltage. And, KERI has completed the reinforcement of the synthetic testing facilities and these facilities have the testing capacity which enables the full-pole testing for 800kV circuit breaker by adopting the series voltage injection method. So, this paper introduced the test circuit and procedures about the full-pole and the multi-part testing method which was devised to estimate the full -insulation of phase-to-ground for the multi-pole and dead-tank circuit breaker.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.635-637
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• 2005

차단기 합성시험은 직접시험과의 등가성을 유지하는 것이 가장 중요한데, 합성시험에서의 전류일 전압은 직접시험에 비해 매우 낮기 때문에 보조차단기 및 피시험 차단기의 아크전압에 의해 마지막 전류루프가 심하게 왜곡될 수 있다. 특히, 비대칭전류차단시험(T100a)에서는 마지막 전류루프의 특성이 차단기 성능평가에 매우 중요한데, 아크전압에 의한 마지막 전류루프의 왜곡이 심하면 합성시험의 등가성이 결여되어 적절치 못한 시험결과를 초래할 수 있다. 따라서 본 논문에서는 아크전압을 고려한 비대칭전류차단 합성시험 특성을 해석함으로써, 적절한 방법에 의해 아크전압에 의한 왜곡을 보상하여 합성시험의 등가성을 유지할 수 있는 기반을 마련하였다.

• 자원리싸이클링
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• 제23권5호
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• pp.12-20
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• 2014

칼슘 페라이트는 소결광 제조 시 생성되는 자용성 소결 광물의 일종으로, 제철 공정의 소결광용 결합제 및 제강용 융제로 사용된다. 기존 소결광용 결합제 및 제강용 융제보다 용융온도가 낮아 결합제 및 융제로서의 효과가 우수하다. 본 연구에서는 제철공정에서 발생하는 다양한 산업부산물을 시작원료로 사용하여 칼슘 페라이트를 제조하였다. 칼슘 페라이트 물성을 분석 평가하기 위해, 시멘트 제조공정 시험법을 준용하였다. 더불어 칼슘 페라이트의 물성을 평가하기 위해 결정분석, 파괴하중, 열분석 등을 시행하였다.