• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2164-2166
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• 1999

This paper is describes the measured electric field waveform radiated by lightning discharge. We have performed measurement and analysis of the electric fields associated with stepped leaders. Electric field measurement system was composed of hemisphere electric field sensor, measurement system of a distance from lightning strokes, automatical recording system, A/D board, personal computer etc. A/D board have high sampling time, high speed data processing, 8bit of resolution. Also, measured characteristics of stepped leaders radiated by were analyzed.

• 한국전자파학회논문지
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• 제7권4호
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• pp.300-309
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• 1996

뇌방전에 의해 방사되는 전계와 자계의 세기는 시변성으로 세기도 대단히 크게 변화하며, 최신의 전자기기에 관련한 전자계 양립성에 대한 과제 중의 하나가 직격뢰뿐만 아니라 근접뢰에 의해 발생하는 과도전압에 대한 효율적이고 경제적인 보호에 관한 것이다. 본 논문에서는 뇌전자계 임펼스파형에 관한 상세한 정보를 얻기 위해서 1995년의 여름에 발생한 뇌방전에 의해 방사된 전계와 자계를 고속전계센서와 루프형 자계센서로 측정한 파형과 이들의 특성을 분석한 결과를 기술 하였다. 전계와 자계의 신호는 12비트의 분해능과 5000포인트의 기억용량을 가지는 기록장치를 이용하여 200 ns 의 시간간격으로 생플링되어 연속적으로 기록하였다. 귀환뇌격시에 방사된 전계와 자계의 파형은 운내방전의 전계와 자계파형과는 매우 달랐다. SOkm이상의 거리 에서 발생한 운내뇌방전에 의해 방사된 자계파형은 전계파형과 거의 일치하였다. 또한 뇌방전에 의해 방사되는 전계와 자계의 주요 주파수 성분은 수 kHz에서 수백 kHz의 범위를 갖는 것으로 나타났다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.215-217
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• 2010

This paper describes the test results of radiated compatibility with Ariane 5 launcher performed on the COMS Satellite test facility. Firstly, the Radiated Emission test results are analyzed in compliance with the Radiated Susceptibility requirement specification of Ariane 5 launcher. The satellite nominal operation is monitored during injection a radiated electric field corresponding to the launcher emissions levels in critical frequency ranges. And also, E-field are measured through a probe located at external units level in order to assess the EMC safety margin in Radiated mode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1656-1658
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• 1998

This paper deals with a measurement system of a distance between lightning strokes and observatory station and spectrum analysis of electric fields radiated from lightning discharges. The distance measurement system, which consists of a loop type magnetic field sensor, a microphone and one chip microprocessor, is connected to a personal computer through RS232 port to acquire and process the data. This system is to use a difference of propagation velocity between an electromagnetic wave and a sonic wave produced by lightning discharge. Also, an electric field waveform and a frequency spectrum were investigated by an electric field measurement system with a hemisphere antenna and a spectrum analyzer with a biconical antenna and a log-periodic antenna, respectively. The results would be used as a basic reference to protect the power systems and electric circuits from lightning overvoltages.

• 한국전자파학회논문지
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• 제27권3호
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• pp.291-298
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• 2016

본 논문에서는 전자파적합성 국제 규격인 IEC 61000-4-4에서 규정하고 있는 전기적으로 빠른 과도현상/버스트(EFT/Burst) 신호가 전원선을 따라 시험대상품에 인가될 때, 인가신호에 기인하여 방사되는 불요전자파와 그 신호가 피시험품에 미치는 영향에 대해 연구하였다. 먼저 국제규격에 규정된 시험 배치방법에 따라 시험 샘플을 설치하고, 검증된 EFT/Burst 발생기로 1분 동안 +4 kV의 규정된 신호를 길이 1 m인 전원선을 통해 시험 샘플에 인가하였다. 그 결과, 전원선을 통해 인가되는 전도성 EFT/Burst 내성 신호 외 버스트 발생기 및 전원선에서 직접 공기 중으로 방출되는 방사성 신호(EFT/Burst 노이즈)가 검출되었고, 국제 공인시험 규격으로 이 신호를 측정한 결과, 규제 레벨보다 30 dB 이상 높았다. 또한, EFT/Burst 방사성 신호의 최대 방사 지점과 시험품의 이격 거리에 따른 전계강도를 측정한 결과, 방사내성 국제 규격치보다 최대 23 V/m 이상 강한 전계강도가 검출되었다. 이는 EFT/Burst 방사성 노이즈가 직접적으로 제품에 인가되어 오동작을 유발할 가능성이 대단히 높으므로 대책이 요구됨을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권3호
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• pp.123-129
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• 2003

In this paper, a relationship between AC discharge progress and the radiated electromagnetic waves was investigated by measuring electromagnetic waves using a biconical antenna and a spectrum analyzer. The frequency spectrum of the radiated electromagnetic waves were measured at the atmospheric pressure in liquid nitrogen($LN_2$) during partial discharges progressed by AC high voltage in nonuniform electric field. Front the results of this study, a new method was introduced for measurement and analysis of the radiated electromagnetic waves with discharge progress in $LN_2$ Besides. according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress could be possible. It is considered that these results obtained from this investigation may be used as fundamental data for diagnosis and prediction of electric insulations about superconducting and cryogenic power equipments.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.604-608
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• 2003

In this paper, we studied the radiated electric field of power-line with DMT signal source in the frequency range of $1.7{\sim}30 MHz$. First, we made the midium voltage power-line communication model for PLC and calculated the current through the power-line using the impedance of the power-line model. Second, we calculated the radiated electric field in power range $-50{\sim}-30 dBm$ using the calculated current. Consequently, the calculated emissive electromagnetic field from the DMT signal is similar to the measured result. So this study is applicable to the standard regulation of electromagnetic interference for PLC.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.98-100
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• 2011

High speed Train Systems are the energy supplied system via the pantograph through which the voltage and the current supplied by the catenary wire flow. The arc discharges generate owing to the contact loss between the catenary and the pantograph, and the electromagnetic fields radiate. There are many different phenomena between the static charges and the moving charges in view of the radiated electromagnetic fields. To calculate the electromagnetic filed about the moving charges, it is necessary to adapt Lorentz transformation. Actually, the particle which moves near the speed of light has the relativisitic phenomena. In addition, it is necessary to predict the electromagnetic field because the radiated electromagnetic field takes effect on the near electronic devices and the human beings. In this paper, we model the arc discharge into the dipole antenna model, adapt Lorentz transformation to the case that the electric railway cars move, and calculate the radiated electromagnetic field. By the calculation, we take the basis upon the electromagnetic prediction, and apply to the future research.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.677-681
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• 2014

A high voltage pulse generator was fabricated to radiate ultrawide band electromagnetic pulse. A coaxial type of Blumlein pulse forming line is employed to produce a pulse of high voltage (>300 kV) and short pulse duration (~5 ns). A helical strip/wire type of air-cored pulse transformer was used to charge the Blumlein pulse forming line up to more than 300 kV. A peaking switch is essential to make the pulse rise time as fast as possible. Typically, the rise time is ~500 ps. The output pulse of the generator is radiated into air through an exponentially tapered TEM horn antenna. The electric field intensity of a radiated pulse was measured as a function of the distance from the transmitting horn as well as the output voltage of the peaking switch. The peak-to-peak value of the electric field intensity at 10 m from the TEM antenna was~100 kV/m.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.447-450
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• 2002

In the surrounding of the electric machinery and equipments occurring of using the electromagnetic fields, other electric machinery or equipments are induced the malfunctions by the radiated and leaked electromagnetic fields. And the human hazardous problems by that effect are being discussed frequently. So efficiently shielding technique of injurious electromagnetic field for high frequency welder is discussed in this paper.