• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.77-78
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• 2007

국제규격에 따라 VCB(vacuum circuit breaker), ACB(air circuit breaker), 등과 같은 전력기기들의 기계적 동작 시험 시, 시험전후의 개폐시간, 개폐속도, 동작코일전류크기, 등과 같은 특성을 측정하고 이들의 변화정도를 평가하여 시험결과를 판단한다. 그러나 시험 중에는 이러한 동작특성들을 측정하지 않기 때문에, 시험 중에 실패하는 경우, 원인 규명에 많은 어려움이 따른다. 이러한 문제를 해결하기 위해, LS산전 PT&T(Power Testing & Technology Institutes)는 시험전후뿐만 아니라 전체시험횟수 동안 동작특성을 측정하고, 이들의 변화추이를 분석할 수 있는 시스템을 구축하고, 관련 소프트웨어를 개발하였다. 본 논문에서는 개발 내용과 결과를 소개하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.544-547
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• 2002

In a high power laboratory, artificial lines are used for SLF tests of circuit breakers. The line side PTRV is affected by the stray capacitances of testing and measuring equipment as well as the circuit parameters of artificial lines. The changing pattern of PTRV was examined, and the circuit parameters of artificial line for some examples were compensated using the changing pattern to satisfy test conditions specified.

• 한국통신학회논문지
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• 제19권6호
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• pp.1038-1045
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• 1994

본 논문에서는 CAM에서 발생하는 모든 PSF(Pattern Sensitive Fault)를 검사하기 위한 알고리즘과 테스트회로를 설계하였다. 즉, 짧은 시간에 최소의 부가회로를 이용하여 외부의 장비에 의존하지 않고 테스트하는 내장 테스트회로를 설계하였다. 부가적으로 첨가된 회로로는 병렬비교기와 오류검출기가 있고, 병렬테스팅을 위해서 수정된 디코더를 사용하였다. 또한, 효과적인 테스트패턴을 구하기 위해 Eulerian path의 구성방법에 대해서도 연구를 수행하였다. 결과적으로, 본 논문에서 사용한 알고리즘을 사용하면 워드수에 관계없이 324+2b(b:비트수) 만큼의 동작으로 CAM의 모든 내용을 테스트할 수 있다. 전체 회로중에서 테스트회로가 차지하는 면적은 약 7.5%정도가 된다.

• 대한전기학회논문지:전력기술부문A
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• 제54권6호
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• pp.284-292
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• 2005

Because all of the short-circuit testing laboratories have the limitation of test facilities, the synthetic making test methods have been used to estimate the short-circuit making performance of the ultra high-voltage circuit breaker as the alternative to direct test methods. So, KERI(Korea Eelctrotechnology Research institute) has completed the construction of the synthetic making test facilities using the low capacity step-up transformer method which fulfill the requirements specified in newly revised IEC 62271-100 Edition 1.1(2003) and have the testing capability up to 550kV, 63kA full-pole circuit breaker. The test facilities using the low capacity step-up transformer method presented in this paper are made up of the unit equipments such as HCS(High-speed Closing Switch), ITMC(Initial Transient Making Current) circuit and UP TR(low capacity step-up transformer) and have the operating range of 17.6$^{\circ}$ $\~$ 145.1$^{\circ}$ for testing the circuit breaker rated on up to 50kA and 43.1$^{\circ}$ $\~$ 119.6$^{\circ}$ for more than 50kA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.161-163
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• 1997

Heatcycle testing for aluminum connector is very important. But because of connecting or disconnecting the test circuit, measuring resistance is difficult. Also the previous measuring resistance instrument is analog type. So measuring method is difficult. And four measuring points for one test circuit cause difficulty in automation. In this paper we developed the automatic system for measuring resistance. Automation will allow more information to be gathered, which will lead to the connector aging process being better understood and controlled.

• Journal of Magnetics
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• 제21권4호
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• pp.570-576
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• 2016

The shape optimization of the stator and the rotor is important for electrical motor design. Among many motor design parameters, the stator tooth and yoke width are a few of the determinants of noload back-EMF and load torque. In this study, we proposed an equivalent magnetic circuit of motor stator for efficient stator tooth and yoke width shape optimization. Using the proposed equivalent magnetic circuit, we found the optimal tooth and yoke width for minimal magnetic resistance. To verify if load torque is truly maximized for the optimal tooth and yoke width indicated by the proposed method, we performed finite element analysis (FEA) to calculate load torque for different tooth and yoke widths. From the study, we confirmed reliability and usability of the proposed equivalent magnetic circuit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.787-789
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• 2000

This paper describes the theory and practical design of Rogowski coil and active integrator. The coils and integrators have the ratings as follows. 1) current ratings between 20kArms and 200kArms 2) current duration 3 seconds 3) time constant of primary circuit looms 4) inner diameter of coil is suitable for mounting at the busbar $200mm{\times}200mm$. The actual results in the short-circuit tests and compare with other sensors, such that shunt. are given also.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.631-635
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• 1993

This paper shows the procedure to determine the physical variables of the simple synthetic testing facility using LC resonance circuit and presents the calculated results of those variables for the LC resonance circuit which can be used to test circuit breakers up to 36kV 40kA class. Attention has also been paid to the advantages of the LC resonance circuit compared with the method adopting short-circuit generator for the development of circuit breakers.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.384-387
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• 1999

In this paper, we have proposed a testing methodology for Speed-Independent asynchronous control circuits using the self-checking property where the circuit detects certain classes of faults during normal operation. To exploit self-checking properties of Speed-Independent circuits, the Proposed methodology generates tests from the specification of the target circuit which describes the behavior of the circuit. The generated tests are applied to a fault-free and a faulty circuit, and target faults can be detected by the comparison of the outputs of the both circuits. For the purpose of efficient comparison, reachability information of the both circuits in the form of BDD's is used and operations are conducted by BDD manipulations. The identification for undetectable faults in testing is also used to increase efficiency of the proposed methodology. The proposed identification uses only topological information of the target circuit and reachability information of the good circuit which was generated in the course of preprocess. Experimental results show that high fault coverage is obtained for synthesized Speed-Independent circuits and the use of the identification process decreases the number of tests and execution time.

• 한국압력기기공학회 논문집
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• 제9권1호
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• pp.40-47
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• 2013

The capacity factor of nuclear power plant in Korea is the highest level in the world. However, the integrity assessment of nuclear power plant is depended on foreign country. Especially, most eddy current testing systems for inspecting steam generators in nuclear power plant are currently imported from USA, Canada, and so on. Therefore, the eddy current testing system can react more active and adaptive from economic and managerial standpoint for actual nuclear power plants in Korea is required. In this paper, an eddy current testing system for inspecting steam generators in nuclear power plants is introduced. Frequency generator, analog circuit, analog digital converter circuit, and digital control circuit are composed in eddy current testing system. A benchmarking of acquisition system and acquisition software, eddynet 11i made by Zetec, and modifications are carried out based on the test environment of Korea nuclear power plants. Finally, all eddy current apparatus are integrated to inspect steam generator tubes in nuclear power plants.