• JOURNAL OF ELECTRICAL WORLD
• /
• no.6 s.90
• /
• pp.100-103
• /
• 1984

배전선로는 전력공급설비의 말단에 있으며 전압의 변동 및 주파수의 변동등이 적은 전기를 공급하는 동시에 정전이 적은 전기를 공급해야 된다. 뇌해에 의한 사고도 내뢰시설의 증강으로 감소경향에 있으며 피뢰기 부착의 증가, 가공지선의 적당한 부탁으로 신뢰도가 높은 배전설비가 되고 있다. 여기서는 배전선로에서 활약하고 있는 피뢰기의 구조를 중심으로 그 메카니즘에 초점을 맞추어 설명하기로 한다.

• 한국ITS학회:학술대회논문집
• /
• v.2006 no.10
• /
• pp.187-190
• /
• 2006

In this paper, the equivalent circuit of tapped-line that is applied in the feeding of the band-pass filter with high coupling is suggested and the value of an equivalent circuit is mathematically defined. An equivalent circuit of tapped-line is composed by open stub and additional transmission line, and the electrical lengths of stub and line can be obtained by the impedance of resonator and the inverter. The new equivalent circuit of tapped-line can be simply applied of design of band-pass filter and leads to very good agreement compared with theoretical value. The coupled-line band-pass filter using equivalent circuit of tapped-line shows the insertion loss of 1.97 dB and the return loss of 18.5 dB at the center frequency of 5.8 GHz.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.410-411
• /
• 2015

765kV 송전선로와 선하 건조물은 최하단 도체의 높이 28m를 적용하고 대지저항률은 $100{\Omega}m$, IEEE 변전소 설계지침인 Std-80에 따라 건조물에 접촉하는 사람의 인체저항은 $1000{\Omega}m$, 대지를 딛고 있는 사람의 한쪽 발 접지저항은 직경 8cm의 원판 접지저항을 적용한다. 이렇게 구성된 모델에서 선로중심에서 건조물까지 이격거리 변동에 따라 인체 유도전류를 측정하고자 한다. 본 연구에서는 전기안전 실증시험을 위해 765kV 가공송전선로 직하에 목조 및 샌드위치 판넬 2가지 시험용 가옥을 설치하였다. 전기설비기술기준에 의거하여 선하직하 이격거리가 28m일 때 발생할 수 있는 전자계 특성과 재질에 따른 전자계가 미치는 영향을 비교 분석하고 장기 유도장해 실측 데이터를 확보하고자 그림 1과 같이 구축 설계하였다. 이를 통해 송전선로에 의해 선로중심으로부터 구축된 모의가옥까지 이격거리에 따라 유도되는 전류를 측정하고 그 크기가 인체에 미치는 유도전류 한계치 초과 여부에 대해 검토함으로써 안전성 여부에 대해 측정 및 검토하고자 시험게획을 수립하였다. 또한 선로 고장 시 대지전위상승에 의한 선하 건조물 안정성 검토 및 낙뢰서지 유입에 의한 전기안전 시험 구성을 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.9
• /
• pp.1949-1956
• /
• 1997

The mode parameters of asymmetrical coupled microstrip lines on composite substrates are derived by using closed form expression. A 10 dB directional couplers, where the center frquency is 1.8 GHZ, are fabricated on a single-layer substrate and on compsite substrates respectively. It is shown that coupler on a single-layer substrate.

• Proceedings of the KIEE Conference
• /
• 2003.11a
• /
• pp.396-399
• /
• 2003

최근 전력산업의 구조개편, 선로건설의 어려움, 송전선로의 노후화, 선로용량 취약개소의 상시감시 필요성 등으로 인하여 선로의 허용 전류용량을 합리적으로 평가하는 한편, 도체의 허용전류를 실시간으로 산정하여 현재 운용상태와 비교하여 그 한계 및 여유 정도를 알아보는 것이 중요한 문제로 대두되었다. 본 논문에서는 이러한 연구의 일환으로 먼저 기상모델을 중심으로 실시간 허용전류 산정 알고리즘에 대하여 살펴보고, 대전 지역의 가공 송전선로를 대상으로 선로 주변의 기온, 풍속, 지형 정보를 이용하여 동적으로 허용전류를 산정하여 그 이용 가능성을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.5
• /
• pp.444-449
• /
• 2009

This paper presents the design of a dual band branch line hybrid coupler(BLHC) with different power division ratios at two bands. In the proposed design, transmission lines of the BLHC are transformed to $\pi$-type equivalent circuits which represent different impedances and $\lambda/4$ electrical length at two frequency bands. In order to verify the proposed method, a dual band coupler with different power division ratios is designed for 0.9 GHz and 2 GHz applications. The desired power division ratios are 1:1 and 1:3 at the two operating frequency bands. The measured results show excellent performance with an insertion loss of less than 0.33 dB, a return loss of less than -18.07 dB, and good isolation characteristics.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.2
• /
• pp.65-71
• /
• 2011

This paper shows variations on bandwidth for the 5-microstrip 4-port structure by cutting out part of 2nd and 4th line of 5 lines. In 2nd line case, the bandwidth to pass is decreased by 300MHz and one of two input ports operates in diplexer. Both of 2nd and 4th line cut takes each of two input ports as a diplexer. The bandwidth for 4th line case has almost same bandwidth for the unmodified structure, a bit wider than that of the 2nd line case. Especially the isolation between input and other out port in center frequency of stop band shows 41dB for port 1, 32dB for port 2.

• Journal of the Korean Society for Railway
• /
• v.16 no.6
• /
• pp.528-533
• /
• 2013

To improve the efficiency and safety of railway systems, the train control system has considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing information and communication technologies (ICT). Accordingly, since the ICT-based train control system simplifies the railway system (i.e. the heavy ground-equipment can be removed), an efficient and cost-effective railway system can be realized. In this paper, we perform a feasibility test of the ICT-based train control system using a simulation. To this end, we implement a test-bed consisting of prototype machines of on-board/ground equipment and introduce an integrated operation scenario for the train control. The simulation results satisfy all the requirements of train operation according to the scenario and show the effectiveness of the proposed train control system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.10
• /
• pp.1409-1415
• /
• 2021

The Gysel divider has the advantage of easily setting the resistor in the circuit. If the line impedance in the Gysel divider is set differently, the input signal can be distributed to the two output ports at various distribution ratios. This paper proposes the Gysel divider that can change the power distribution to 1:3 or 3:1 by changing the line impedance. The impedance change of the line can be implemented by placing a floating copper plate on the bottom of the microstrip-line. When the floating copper plate and the ground plane are connected, the line operates as the microstrip-line, and when the floating copper plate and the ground plane are disconnected, the line operates as the coplanar-line. The proposed Gysel divider was fabricated at the center frequency of 1.5GHz. The fabricated 3:1 Gysel divider has a stable value S₁₁ of below -17dB, S₂₁/S₃₁ of 4.8±0.2dB, S₂₁(to high output port) of -1.39±0.12dB and S₃₁(to low output port) of -6.15±0.08dB over 1.3~1.7GHz.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.3
• /
• pp.565-573
• /
• 2000

In this paper, a interdigital microstrip bandpass filter is designed. A interdigital microstrip bandpass filter has many advantages such as insertion return loss, lower return loss, higher frequency selectivity and smaller in size in comparison with the conventional coupled line filter. A interdigital microstrip bandpass filter consists of quasi TEM-mode strip line resonators between parallel ground plant. Each resonator element is a quarter wavelength long of the center frequency and is short circuited at one end and open circuited at the other end. In the filter design, Ensemble software is used. Experimental results show that the bandwidth of interdigital microstrip bandpass filter is 2.52GHz, insertion loss is -1.8dB and return loss is -17.0dB at 11.20Hz.