• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.208-209
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• 2006

Voltage Transformer is used to transform high voltage into low voltage to input signal of protection relay. Most of the Voltage Transformers use the iron core which maximizes the flux linkage. The ratio of the Voltage Transformer depends on the transformer turns ratio. The current which flows in the Voltage Transformer has non-linear characteristic caused by hysteresis of the iron core, it causes a voltage loss in the winding impedances which makes measurement errors. This paper describes an error compensation method considering hysteresis characteristic. The proposed compensation method improves error by calculating the primary current from the exciting current of the hysteresis loop in the Voltage Transformer, compensating the voltage loss.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.205-207
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• 2005

In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000 - 3 - 6 in Electromagnetic Compatibility(EMC). Harmonic voltage and current were measured at the PCC of real distribution system. Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified by measurement. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current in steady-state. Harmonic transfer characteristic in distribution system were summarized and investigated through a analysis of harmonic voltage and harmonic current in harmonic current source.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.581-583
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• 1997

In this paper, we present a temperature characteristic in OPGW link due to meteological effects. we measured a temperature on a 2km OPGW using a distributed optical fiber temperature sensing system. The measurement showed that OPGW temperature was several degrees lower to ambient atmospheric temperature in the nighttime and several degrees higher than that in the daytime due to sunshine. It'll be used for a reference data of the transmission delay variations in OPGW link due to meteorological effects.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.58-60
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• 1999

In the industrial field the necessity of the linear motion is increasing. We selected a moving magnet coreless type LDM, which have the advantages, such as long stoke, brushless, no cogging force. Actually, the design is accomplished using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In the course of design, we have estimated airgap flux density and thrust. We fabricated coreless type LDM and experimented static test. We compared measurement values with FEM analysis values.

• 전기전자학회논문지
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• 제22권4호
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• pp.907-915
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• 2018

본 논문에서는 저가형 적외선 거리 센서의 성능을 개선하는 방법을 제안한다. 적외선 거리 센서는 반사광의 강도를 측정하여 거리로 환산한다. 제안하는 방법은 센서의 감지 거리를 개선하고 다양한 조명환경에서도 강인하게 동작하도록 한다. 이는 센서의 특성곡선을 추출하고 이를 바탕으로 HDR(High Dynamic Range) 기법을 적용함으로써 가능해졌다. 적외선 입력의 세기와 노출 시간을 다양하게 변화시켜서 센서의 출력값을 획득하였고 이로부터 센서의 특성곡선을 추출하였다.

• 조명전기설비학회논문지
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• 제21권3호
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• pp.62-68
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• 2007

최근 전력 전자 응용 기기의 사용증가로 비선형 특성 부하에 의한 고조파가 상당히 발생하고 있으며, 이에 의한 영향으로 배전시스템의 변압기 열화, 소자의 고장, 통신 간섭 등의 여러 가지 문제를 발생시키고 있다. 따라서 배전 시스템에서의 고조파 수준과 전달특성을 정확하게 분석하기 위하여 배전시스템의 효과적인 실측정과 모델링에 관한 연구가 필요한 실정이다. 본 논문에서는 고조파 관리기준 IEC61000-3-6 토대로 배전 시스템의 고조파 특성을 해석하기 위하여 공통 결합점(Point of Common Coupling : PCC)을 선택하였다. 실 배전 시스템의 PCC 지점에서 고조파 전압, 전류를 측정하여, 고조파 분포, 비선형 부하 성분 및 고조파 전압, 전류 왜형률 (Voltage/Current Total Harmonic Distortion: VTHD/ITHD)을 분석하였다. 또한 정상상태에서 고조파 임피던스, 전압, 전류을 해석을 통하여 실 배전시스템을 효과적이고 정확하게 모델링 되었을 확인하였다. 또한 고조파 전류원 발생시에 고조파 전압, 전류를 비교 분석하여 고조파 전달특성을 조사하였다.

• 조명전기설비학회논문지
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• 제23권5호
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• pp.36-41
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• 2009

본 논문에서는 건축물 전기설비의 IEC 60364를 기반으로 개발된 점검기법을 이용하여 실태 조사를 실시하였다. 점검기법 개발을 위한 분석대상은 기술기준에 준하여 시공된 국내 건축전기설비와 IEC 60364로 시공된 건축전기설비를 대상으로 차이점을 분석하였다. 측정 요소는 Loop impedance, 차단기 동작특성, 보호도체의 연속성을 측정하였다. 조사결과 국내 건축전기설비의 경우 TT시스템과 유사하지만 보호도체의 연속성에 문제가 있었다. TN-C-S로 시공된 건축전기설비의 경우 시공은 정확하게 되어 있었으나 담당자의 IEC 60364와 관련된 이해가 부족한 상태였다.

• 한국전기전자재료학회논문지
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• 제11권11호
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• pp.1035-1042
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• 1998

After the 1990's, a computer-aided partial discharge(PD) measurement system was referred in part of aging diagnosis using digital signal processing as the new technology has been studied. The PD patterns and relevant information for pattern recognition are discussed in PD research area, because discharge quantity(q), the number of discharge pulse(n) and the applied boltage phase($\varphi$) was combined with the system information of the aging state. This paper investigates the discharge phase and quantity, as well as the number of discharge(n) with regard to discharge signals generated in power cable. therefore, according to characteristic analysis on the distribution of $\varphi$, q and n, it is able to apply in the aging analysis of power cable which visual observation is impossible and distribution change of discharge signals offers much information for risk degree on aging progress of insulation materials.

• 한국전기전자재료학회논문지
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• 제15권11호
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• pp.1003-1008
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• 2002

In this paper, the estimation of lifetime with the various conditions of the interface between toughened epoxy and rubber which are consisting materials of underground power delivery system has been studied. After the measurement of the short time AC interfacial breakdown strength on macro interfaces at room temperature, the breakdown time at several voltages were measured under the constant voltages lower than the short time breakdown voltage. The long time breakdown voltage was calculated by using Inverse Power Law. Two types of interfaces was studied. One was the interface between toughened epoxy and EPDM(Ethylene Prorylene Diene Terpolymer). The other was the interface between toughened epoxy and silicon rubber. Interfacial pressure and roughness of interfaces was determined through the characteristic of short time AC interfacial breakdown strength. Oil condition was no oiled, low viscosity oiled and high viscosity oiled. High viscosity oiled interface between Toughened epoxy and silicon rubber had the best lifetime exponent, 20.69. and the breakdown voltage of this interface after 30 years was evaluated 19.27㎸.

• 한국전기전자재료학회논문지
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• 제23권5호
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• pp.358-363
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• 2010

The polishing pad is important element for polishing characteristic such as material removal rate(MRR) and within wafer non-uniformity(WIWNU) in the chemical mechanical planarization(CMP). The result of the viscoelasticity measurement shows that 1st elastic modulus is increased and 2nd elastic modulus is decreased when the top pad is thickened. The finite element analysis(FEA) was conducted to predict characteristic of polishing behavior according to the pad thickness. The result of polishing experiment was similar with the FEA, and it shows that the 1st elastic modulus affects instantaneous deformation of pad related to MRR. And the 2nd elastic modulus has an effect on WIWNU due to the viscoelasticity deformation of pad.