• 제목/요약/키워드: transmission line

검색결과 3,298건 처리시간 0.033초

765 kV 송전선로의 345 kV 운전에 따른 계통 해석 (The analysis result of temporary operation of 765 kV transmission line as 345 kV rating)

  • 우정욱;심응보;강연욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1647-1649
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    • 1998
  • This paper describes the power frequency voltage and its countermeasure when a 765 kV transmission line is directly connected to a 345 kV line and operated at 345 kV voltage. The summary of this result is as follows : The western route of 765 kV transmission line doesn't need any countermeasure to reduce the power frequency voltage at the receiving end. The eastern route of 765 kV transmission needs 100 Mvar(3 phase) capacity of shunt reactor at the receiving end to reduce the power frequency voltage. The use of shunt reactors in the 765 kV transmission lines has unexpected problems, one of which is induction of high voltages on a de-energized circuit of two parallel lines. This paper examined the problem of resonance on two parallel transmission circuits in one routes.

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초고압 송전선로의 최적 격상전압 선정에 관한 연구-리비아국 사례 (A STUDY ON OPTIMAL UPGRADING VOLTAGE OF EHV GRID NETWORK-LYBIAN CASE)

  • 김봉희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 D
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    • pp.1041-1043
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    • 1997
  • When a new transmission line is planned to construct, the system voltage and the conductor size of the transmission line should be decided by both economical and technical point of view. This paper presents a methodology to determine the optimal voltage for upgrading the transmission system voltage of existing the extra high voltage grid network by meeting the requirements of the transmission cost minimization as well as technical constraints of thermal limit and stability limit in the transmission line. As a case study, calculated are optimal voltages versus distance and capacity of a practically applicable transmission line with 4 bundles 2 circuits. By this study 400kV was selected as the next higher voltage for the existing 220kV Libyan grid network.

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Finite element modelling of transmission line structures under tornado wind loading

  • Hamada, A.;El Damatty, A.A.;Hangan, H.;Shehata, A.Y.
    • Wind and Structures
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    • 제13권5호
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    • pp.451-469
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    • 2010
  • The majority of weather-related failures of transmission line structures that have occurred in the past have been attributed to high intensity localized wind events, in the form of tornadoes and downbursts. A numerical scheme is developed in the current study to assess the performance of transmission lines under tornado wind load events. The tornado wind field is based on a model scale Computational Fluid Dynamic (CFD) analysis that was conducted and validated in a previous study. Using field measurements and code specifications, the CFD model data is used to estimate the wind fields for F4 and F2 full scale tornadoes. The wind forces associated with these tornado fields are evaluated and later incorporated into a nonlinear finite element three-dimensional model for the transmission line system, which includes a simulation for the towers and the conductors. A comparison is carried between the forces in the members resulting from the tornadoes, and those obtained using the conventional design wind loads. The study reveals the importance of considering tornadoes when designing transmission line structures.

결함접지구조와 가유전체 기판구조를 결합한 전송선로의 설계 (Design of a Transmission Line using Defected Ground Structure and Artificial Dielectric Substrate)

  • 권경훈;임종식
    • 한국산학기술학회논문지
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    • 제14권7호
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    • pp.3474-3481
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    • 2013
  • 본 논문에서는 결함접지구조와 가유전체 기판구조를 이용하여 새로운 초고주파 대역 전송선로 구조가 제안된다. 결함접지구조는 전송선로의 단위길이당 등가의 인덕턴스를 증가시켜 동일한 선폭일 때 전송선로의 특성 임피던스를 키우면서 선로의 길이를 줄여준다. 가유전체 기판구조는 전송선로의 단위길이당 등가의 커패시턴스를 증가시켜, 동일한 선폭일 때 전송선로의 특성 임피던스를 낮추면서 선로의 길이를 줄여준다. 따라서 결함접지구조와 가유전체 기판구조는 모두 전송선로의 길이를 줄이면서 선폭에 대해서는 상보적인 역할을 한다. 그러므로 두 구조가 결합되면 전송선로의 특성 임피던스는 크게 변하지 않은 채 길이만 더욱 줄일 수 있으므로, 초고주파 회로의 소형화에 크게 유리하다. 본 논문에서는 결함접지구조와 가유전체 기판구조를 모두 결합시킨 $35{\sim}100{\Omega}$ 전송선로를 설계하고, 실제로 제작 및 측정하여 그 결과를 제시하는데, 특성 임피던스의 예측값과 측정값이 잘 일치함을 보인다. 동일한 전기적 길이에 대하여 제안한 전송선로는 Fig.준형 마이크로스트립 전송선로에 비하여 불과 55.4~76.9% 물리적 길이를 갖는다.

확률적인 소실점 추정 기법에 기반한 강인한 송전선 검출 방법 (A Robust Power Transmission Lines Detection Method Based on Probabilistic Estimation of Vanishing Point)

  • 유주한;김동환;이석;박성기
    • 로봇학회논문지
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    • 제10권1호
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    • pp.9-15
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    • 2015
  • We present a robust power transmission lines detection method based on vanishing point estimation. Vanishing point estimation can be helpful to detect power transmission lines because parallel lines converge on the vanishing point in a projected 2D image. However, it is not easy to estimate the vanishing point correctly in an image with complex background. Thus, we first propose a vanishing point estimation method on power transmission lines by using a probabilistic voting procedure based on intersection points of line segments. In images obtained by our system, power transmission lines are located in a fan-shaped area centered on this estimated vanishing point, and therefore we select the line segments that converge to the estimated vanishing point as candidate line segments for power transmission lines only in this fan-shaped area. Finally, we detect the power transmission lines from these candidate line segments. Experimental results show that the proposed method is robust to noise and efficient to detect power transmission lines.

가공송전선로와 지중송전선로가 연계된 혼합송전선로에서 디지털 거리계전 알고리즘 (A Digital Distance Relaying Algorithm in Combined Transmission Line Connected whth Overhead Line and Underground Cable)

  • 하체웅;이종범
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.440-442
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    • 2000
  • This paper describes the digital distance algorithm in case of combined transmission line connected with overhead line and underground cable. Actually as fault is occurred in cable, it results in the complicated phenomena due to the several kind of grounding method in the sheath of cable. Accordingly the impedance. Therefore the correct impedance calculation algorithm is requested in combined transmission line to avoid the wrong trip of relay. This paper presents the development result of impedance calculation algorithm In such transmission line.

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철도에서 DSL 모뎀을 사용한 데이터 전송에 관한 고찰 (An investigation of data transmission scheme using DSL modem)

  • 조봉관;최규형;장석각
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.1446-1448
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    • 2004
  • Communication line used in the rail-road have different use from subscriber line in the public telecommunication. But, when an existing communication equipment is replaced, by applying new high-speed transfer technology, we can anticipate the increase of transmission rate and decrease of waiting time according to high-speed of communication line. cost reduction of infrastructure construction and maintenance/repair according to centralization of communication line and transmission equipment. In this study, the transmission scheme of several xDSL(Digital Subscriber Line) modems were compared and analyzed. The way of applying xDSL modem to the metal cable which is used in the JR(Japan Railroad) is analyzed. In addition, the result tested in railroad communication line was reviewed.

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실리콘에 기초한 새로운 크로스바 구조의 손실있는 대칭 결합선로에 대한 유한차분법을 이용한 해석 (Analysis of Symmetric Coupled Line with New Crossbar Embedded on Si-based Lossy Structure using the FDTD Method)

  • Kim, Yoonsuk
    • 한국군사과학기술학회지
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    • 제4권2호
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    • pp.122-129
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    • 2001
  • A characterization procedure for analyzing symmetric coupled MIS(Metal-Insulator-Semiconductor) transmission line is used the same procedure as a general single layer symmetric coupled line with perfect dielectric substrate from the extraction of the characteristic impedance and propagation constant for even- and odd-mode. In this paper, an analysis for a new substrate shielding symmetric coupled MIS structure consisting of grounded crossbar at the interface between Si and SiO2 layer using the Finite- Difference Time-Domain(FDTD) method is presented. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded crossbar lines over time-domain signal has been examined. Symmetric coupled MIS transmission line parameters for even- and odd-mode are investigated as the functions of frequency, and the extracted distributed frequency- dependent transmission line parameters and corresponding equivalent circuit parameters as well as quality factor for the new MIS crossbar embedded structure are also presented. It is shown that the quality factor of the symmetric coupled transmission line can be improved without significant change in the characteristic impedance and effective dielectric constant.

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345kV 혼합송전선로에서 재폐로가 절연설계에 미치는 영향 (Effects of Reclosing for Insulation Coordination in 345kV Combined Transmission Lines)

  • 이종범;정채균;임광식;강지원
    • 전기학회논문지
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    • 제59권5호
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    • pp.847-853
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    • 2010
  • This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with XLPE power cable. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as length ratio of power cable section, arrestor, inserting resistance, charging rate, grounding resistance, etc.. On the other hand sheath voltage on IJ(Insulated Joint) is analyzed to check dangerous condition on cable cover. Analysis is performed by EMTP/ATP. Analysis results show that reclosing can be operated as the single line-to-ground fault occurs on overhead line in 345kV combined transmission line, if the inserting resistance is considered before the operation of main circuit breaker.

대규모 계통의 디지털 시뮬레이션을 위한 계통분할 기법이 관한 연구 (A Study on Power System Decomposition Technique for Digital Simulation of Large Power System)

  • 이철균;이진;김태균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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    • pp.171-173
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    • 2002
  • This paper presents a power system decomposition technique for digital simulation of large power system. To decompose power system, distributed transmission line model is used. But this model can be used only for long transmission lines. In this paper, capacitor compensation method is proposed to use distributed transmission line model for short transmission line. And case study shows proposed method can be used for effective power system decompositon in digital simulation of large power system.

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