• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.298-302
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• 2010

We investigated the resistance change behavior of SABiT (Samsung Advanced Bump interconnection Technology) technology-applied PCB (Printed Circuit Board) with the various bump sizes and fabrication conditions. Many testing samples with different bump size, prepreg thickness, number of print on the formation of Ag paste bump, were made. The resistance of Ag paste bump itself was calculated from the Ag paste resistivity and bump size, measured by using 4-point probe method and FE-SEM (Field Emission Scanning Electron Microscope), respectively. The contact resistance between Ag paste bump and conducting Cu line were obtained by subtracting the Cu line and bump resistances from the measured total resistance. It was found that the contact resistance drastically changed with the variation of Ag paste bump size and the contact resistance had the largest influence on total resistance. We found that the bump size and contact resistance obeyed the power law relationship. The resistance of a circuit in PCB can be estimated from this kind of relationship as the bump size and fabrication technique vary.

• 대한전자공학회논문지SD
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• 제40권4호
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• pp.34-41
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• 2003

혼성신호 회로에 발생할 수 있는 각종 파라메트릭 폴트를 검사하기 위한 새로운 기법을 제안한다. LFSR에서 발생하는 랜덤신호를 사용하여 테스트 입력으로 사용하며, 웨이블릿으로 테스트 출력을 분석하고 압축하는 방법을 사용한다. 웨이블릿은 테스트 출력을 다른 여러 주파수 대역으로 분석하여 각각에 대한 응답 신호를 발생시킨다. 각각의 신호는 디지털 적분기를 사용하여 압축된다. LFSR에서 발생된 테스트 입력신호는 전체 주파수 영역에서 일정한 값을 유지하게 되며 따라서 multi-frequency 응답을 발생시켜 준다. 제안된 방법은 실험을 통하여 성능을 검증하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.317-324
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• 2014

The forces involved in the firing of the electromagnetic rail gun may be analyzed from Amperian, Maxwellian and Einsteinian approaches. This paper discusses these different paradigms with regard to rail gun performance modeling relating to the generation and balance of the forces caused by the currents and their induced magnetic fields. Recent experimental work on model rail guns, where the armature is held static, shows very little recoil upon the rails, thereby indicating a possible violation of Newton's Third Law of Motion. Dynamic testing to show this violation, as suggested by the authors in an earlier paper, has inherent technical difficulties. A purpose-built finite element C/C++ simulator that models that suspended rail gun firing action shows a net force acting upon the entire rail gun system. A new effect in physics, universal in scope, is thus indicated: a current circulating in an asymmetric and rigid circuit causes a net force to act upon the circuit for the duration of the current. This conclusion following from computer simulation based upon Maxwellian electrodynamics as opposed to the more modern relativistic quantum electrodynamics needs to be supported by unambiguous experimental validation.

• 전기학회논문지
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• 제63권12호
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• pp.1726-1731
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• 2014

This paper shows the developed new lightning arrester LCM (Leakage Current Measuring device) which is important element of GIS (Gas Insulated Switchgear) Preventive & Diagnostic system and verify its performance though strengthened test standards. The existing lightning arrester LCM was modified to solve measuring errors which happened frequently. At first, we explained the principle of measuring leakage current. Through analyzing some problems which the existing LCM have. we got some improvable items. For the performance verification of the improved LCM, we manufactured prototype LCM which is applied some improvable items such as improving LCM circuit, adding protection circuit, optimizing inner structure of LCM and changing ground design. After then we carried out the performance test. Accredited testing laboratory carried out the performance verification test according to performance test criteria and procedure of reliability test standards, IEC-60225, 61000 and 60068 etc. We confirmed the test results which correspond with the performance test criteria. Also, we confirmed the performance of the improved LCM installed & being operated at G Substation through the immunity test against the normal noise and open/close surge etc.

• 한국멀티미디어학회논문지
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• 제4권6호
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• pp.570-578
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• 2001

경계 주사 구조(Boundary Scan Architecture)기 법은 복잡한 인쇄 회로 기판(PCB : Printed Circuit Board)을 테스트하기 위해 도입되었다. 이러한 경계 주사 구조는 시스템의 정상 동작에 간섭을 주지 않고 시스템의 동작 상태를 실시간 모니터링 하는데 대단한 잠재력을 지니고 있다. 본 논문에서는 경계 주사 구조를 이용하여 시스템의 작동 상태를 실시간으로 모니터 하기 위한 새로운 실장 제어기를 제안하고 설계한다. 제안된 실시간 모니터링 실장 제어기는 경계 주사 구조의 경계 주사 셀 제어기(Test Access Port Controller)와 범용 실장 제어기(Embedded Controller)로 구성되어 있다. 제안된 경계 주사 구조를 이용한 실시간 모니터링 실장제어기는 하드와이어의 자원을 절약해 주고 경계 주사 구조를 지니고 있는 칩에 쉽게 인터페이스 된다. 실험 결과는 제안된 실장제어 기가 시스템의 동작 상태를 실시간 모니터 하는데 호스트 컴퓨터에 의한 모니터 링에 비해 효과적임을 보여준다.

• Journal of electromagnetic engineering and science
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• 제13권4호
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• pp.233-239
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• 2013

This paper proposes an accurate approach for predicting transferred power from a noise source to integrated circuits based on the characteristics of the power transfer network. A power delivery trace on a package and a printed circuit board are designed to transmit power from an external source to integrated circuits. The power is demonstrated between an injection terminal on the edge of the printed circuit board and integrated circuits, and the power transfer function of the power distribution network is derived. A two-tier calibration is applied to the test, and scattering parameters of the network are measured for the calculation of the power transfer function. After testing to obtain the indispensable parameters, the real received and tolerable power of the integrated circuits can be easily achieved. Our proposed estimation method is an enhancement of the existing the International Electrotechnical Commission standard for precise prediction of the electromagnetic immunity of integrated circuits.

• Journal of Advanced Marine Engineering and Technology
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• 제37권5호
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• pp.520-526
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• 2013

전력설비 용량의 증가와 기술의 진보에 따라 회전기가 대용량, 고전압화 되고 있다. 그러므로 발전기 고장예방을 위한 진단시스템의 필요성이 점차 증대되고 있다. 따라서 본 논문에서는 동기발전기 불시 정지 사고에 따른 피해를 예방할 수 있는 고장진단 시스템을 개발하였다. 고장진단 시스템을 검증하기 위해 실제 동기발전기와 권선구조가 같은 소규모의 시험장비를 제작하였다. 또한 회전자권선의 단락을 진단하기 위해 홀센서와 검출시스템을 구성하여 정상상태 뿐 아니라 회전자권선 단락 등 다양한 고장상태에 대한 공극자속파형을 검출하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.845-847
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• 2004

단락시험시 시험회로의 주요 파라미터들은 시험전압과 시험전류를 이용하여 결정된다. 특히, 단락전류의 경우 전류파형의 피크치, RMS, 시간, DC-성분, 역률 등을 분석프로그램을 이용하여 분석하게 된다. 그러나 이러한 분석프로그램은 각 시험기관마다 다르고, 현재까지 분석프로그램을 검증할 국제저인 기준이 존재하지 않았다. 그러나 최근 들어 STL(Short-circuit Testing Liason)에서는 각 시험기관마다 상이한 분석프로그램을 검증할 절차에 대한 연구를 수행하여 왔으며 그 첫 번째로 단락전류 분석프로그램에 대한 성능 평가 절차가 어느 정도 완성되었다. 이에 본 논문에서는 STL에서 배포한 TDG(Test Data Generator)를 이용해reference curve를 생성하고, 전기연구원의 전류분석프로그램을 사용하여 분석프로그램의 신뢰성을 평가하여 보았다.

• 전력전자학회논문지
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• 제19권1호
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• pp.51-56
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• 2014

PV cell modeling is necessary both for software and hardware simulators in analyzing and testing the performance of PV generation systems. Unique I-V curve of a PV cell identifies its own characteristics by electrical equivalent model that is composed of diode constants ($I_o$, $v_t$), photo-generated current ($I_{ph}$), series resistance ($R_s$), and shunt resistance ($R_{sh}$). Photo-generated current can be easily estimated since it is proportional to irradiation level. However, other electrical parameters should be solved from the manufacturer's data sheet that is consisted with three remarkable operating points such as open circuit voltage ($V_{oc}$), short circuit current ($I_{sc}$), and maximum power voltage/current ($V_{MPP}/I_{MPP}$). This paper explains and analyzes mathematical process of a novel PV cell modeling algorithm that was proposed by the authors with the name of "K-algorithm".

• Journal of Electrochemical Science and Technology
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• 제15권2호
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• pp.242-252
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• 2024

To date, methods used to assess the interfacial transition zone (ITZ), which represents the boundary between the aggregate and paste inside concretes, have primarily relied on destructive tests, and non-destructive tests has received little attention until recently. This study assessed the interfaces of concretes with lightweight aggregates based on electrochemical impedance spectroscopy (EIS) for high-strength concretes and examined the possibility of estimating the compressive strength of concretes through non-destructive testing using EIS. The experimental results revealed that the impedance of the hardened cement increased with increasing compressive strength and aggregate density. In particular, when the results of impedance measurement were displayed as a Nyquist plot, the intercept of the x-axis depicting the effective conductivity was proportional to the compressive strength. Furthermore, an equivalent circuit was selected to interpret the correlation between cement aggregates and impedance. Consequently, the compressive strength was found to increase with the value of the resistances of the electrolyte filled in continuous pores in the cement aggregate. And, the pores formed in the ITZ affect this value. The resistance at the ITZ for different aggregates was also obtained, and it was found that the resistance was consistent with the results predicted by SEM images of the ITZ and correlated with the strength of the concretes. The proposed method can be used as a way to easily determine the strength of cement according to differences in aggregate.