• Title, Summary, Keyword: Transmission Line

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Development a computer system to support the route selecting and surveying of a transmission line (송전선 설계지원 SYSTEM의 구축)

  • Jung, Tay-Ho;Kim, Shin-Chul;Lee, Chong-Soo;Kim, Choon-Gu;Kang, Hee-Kwon;Kim, Jung-Ho
    • Proceedings of the KIEE Conference
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    • pp.831-833
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    • 1998
  • It is getting more difficult to construct new transmission lines, due to the increase of people's demand resulting from the change of social environment and people's consciousness. In order to solve these complicated conditions. we developed a computer system to support the route selecting and surveying of a transmission line. This paper introdouces the methodology for route selecting, designing, surveying of a transmission line and tower designing process using a computer system.

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A Study on the Modeling of a Position Control System with a Pneumatic Cylinder Considering Transfer Characteristics of a Transmission Line (전달 관로의 전달특성을 고려한 공기압 실린더 구동장치의 모델링에 관한 연구)

  • Kang B.S.;Jang J.S.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.1 no.2
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    • pp.20-25
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    • 2004
  • In this study, a position control characteristics of pneumatic cylinder with transmission line is analyzed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing stiles of the fluid the diameter and the length of the line. But, the effect of the change of dynamic characteristics of transmission line by the flowing states on the position control characteristics can be neglected because of the friction force of the pneumatic cylinder. So, We assume that the position control characteristics is affected by the diameter and length of the transmission line. The experimental results according to the change of parameter of the transmission line show that the relation between the parameter of the transmission line and the position control characteristics of pneumatic cylinder driving system with the transmission line.

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New Technology on Routing and Surveying a 765kV Transmission Line (765kV 송전선로 경과지선정 및 설계측량에 신기술 도입 적용)

  • Lee, Seog-Kyu;Kim, Choon-Gu;Kang, Hee-Kwon;Kim, Jeong-Ho
    • Proceedings of the KIEE Conference
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    • pp.822-824
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    • 1997
  • The routing and surveying a transmission line should be done in advance of its construction. It is getting more difficult to construct transmission line day by day, due to the rapid increase of people's demand resulting from the recent change of social environment and people's consciousness. In order to solve these complicated conditions actively and rationally, it is necessary to be more scientific, objective and computerizable for the routing and surveying of a transmission line. New technologies on routing and surveying a 765kV transmission line are remote sensing, Global Positioning System and Optimal PowerLine system. Thanks to these technologies, there will be a contribution to making sure of the best quality and developing technolo91r of transmission line.

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A Slotted Triangular-Patch Type Artificial Transmission Line (슬롯을 가진 삼각패치형 인공전송선로)

  • Oh, Song-Yi;Choi, Kyung;Hwang, Hee-Yong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.9 no.4
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    • pp.164-167
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    • 2010
  • In this paper, an artificial transmission line of triangular-patch type with slots is proposed. This artificial transmission line is useful for miniaturizing the electrical lengths of conventional transmission lines. Also, this structure is easy to regulate the characteristic impedance and electrical lengths. The electrical lengths and the characteristic impedances of the proposed artificial transmission line with some parameters are researched and summarized The proposed artificial transmission line could be useful for compact designs for most of the passive microwave components. The optional-artificial transmission line is fabricated and measured at 2.45GHz.

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Estimation Technique of Power Transmission Line Parameter by Phasor Measurement Units (송전선로 파라메터 정밀 예측을 위한 페이저 측정기의 응용)

  • Cho, Ki-Seon;Park, Jong-Bae;Shin, Joong-Rin
    • Proceedings of the KIEE Conference
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    • pp.193-195
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    • 2003
  • This paper presents an approach to estimate the power transmission line parameter by phasor measurement units(PMUs), which are synchronized to 1 pps signal of GPS. Existing approaches to estimate power transmission line parameter, are mainly off-line ones, based on faults or switching events on other neighboring lines. In this paper, to obtain static and dynamic properties of power transmission line parameter in service, the prototype of pmu-based Transmission Line Parameter Monitoring System (TLPMS) is proposed. Also, an technique to estimate parameters of transmission line described as 2-port network model and the soundness of estimated parameters are addressed.

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Equivalent Transmission-Line Sections for Very High Impedances and Their Application to Branch-Line Hybrids with Very Weak Coupling Power

  • Ahn, Hee-Ran;Kim, Bum-Man
    • Journal of electromagnetic engineering and science
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    • v.9 no.2
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    • pp.85-97
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    • 2009
  • As operating frequency is raised and as more integration with active and passive elements is required, it becomes difficult to fabricate more than 120 ${\Omega}$ characteristic impedance of a mierostrip line. To solve this problem, an equivalent high impedance transmission-line section is suggested, which consists mainly of a pair of coupled-line sections with two shorts. However, it becomes a transmission-line section only when its electrical length is fixed and its coupling power is more than half. To have transmission-line characteristics(perfect matching), independently of coupling power and electrical length, two identical open stubs are added and conventional design equations of evenand odd-mode impedances are modified, based on the fact that the modified design equations have the linear combinations of conventional ones. The high impedance transmission-line section is a passive component and therefore should be perfectly matched, at least at a design center frequency. For this, two different solutions are derived for the added open stub and two types of high impedance transmission-line sections with 160 ${\Omega}$ characteristic impedance are simulated as the electrical lengths of the coupled-line sections are varied. The simulation results show that the determination of the available bandwidth location depends on which solution is chosen. As an application, branch-line hybrids with very weak coupling power are investigated, depending on where an isolated port is located, and two types of branch-line hybrids are derived for each case. To verify the derived branch-line hybrids, a microstrip branch-line hybrid with -15 dB coupling power, composed of two 90$^{\circ}$ and two 270$^{\circ}$ transmission-line sections, is fabricated on a substrate of ${\varepsilon}_r$= 3.4 and h=0.76 mm and measured. In this case, 276.7 ${\Omega}$ characteristic impedance is fabricated using the suggested high impedance transmission-line sections. The measured coupling power is -14.5 dB, isolation and matching is almost perfect at a design center frequency of 2 GHz, showing good agreement with the prediction.

A Reassessment for Dynamic Line Rating of Aged Overhead Transmission Lines in Kepco's Network (한국전력 노후 가공송전선의 동적송전용량에 대한 재평가)

  • Kim, Sung-Duck
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.10
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    • pp.123-129
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    • 2010
  • During the past 2 decades, many electric power companies have been searching various solutions in order to supply power with economical and more efficiency in the present transmission utilities. Most interesting method to increase the line capacity of overhead transmission lines without constructing any new line might be to adapt Dynamic Line Rating(DLR). Specified rating is normally determined by any current level, not by conductor temperature. Although specified rating is essential to design transmission line, dip may be the most important factor in limiting transmission capacity. Transmission lines built by the oldest dip criterion among the 3 different design criteria for conductor dip are nearly over one-half of all Kepco's transmission lines. This paper describes an up-rating method for those transmission lines in order to apply DLR technique. Based on limit dip conductor temperature and current of the transmission lines, limitation performance and effectiveness in applying DLR with weather model are analyzed. As a result of analysis, it can be shown that an improved method could be effectively used for increasing the line rating of old transmission line which was built by the design criterion with low dip margin.

Response evaluation and vibration control of a transmission tower-line system in mountain areas subjected to cable rupture

  • Chen, Bo;Wu, Jingbo;Ouyang, Yiqin;Yang, Deng
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.151-171
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    • 2018
  • Transmission tower-line systems are commonly slender and generally possess a small stiffness and low structural damping. They are prone to impulsive excitations induced by cable rupture and may experience strong vibration. Excessive deformation and vibration of a transmission tower-line system subjected to cable rupture may induce a local destruction and even failure event. A little work has yet been carried out to evaluate the performance of transmission tower-line systems in mountain areas subjected to cable rupture. In addition, the control for cable rupture induced vibration of a transmission tower-line system has not been systematically conducted. In this regard, the dynamic response analysis of a transmission tower-line system in mountain areas subjected to cable rupture is conducted. Furthermore, the feasibility of using viscous fluid dampers to suppress the cable rupture-induced vibration is also investigated. The three dimensional (3D) finite element (FE) model of a transmission tower-line system is first established and the mathematical model of a mountain is developed to describe the equivalent scale and configuration of a mountain. The model of a tower-line-mountain system is developed by taking a real transmission tower-line system constructed in China as an example. The mechanical model for the dynamic interaction between the ground and transmission lines is proposed and the mechanical model of a viscous fluid damper is also presented. The equations of motion of the transmission tower-line system subjected to cable rupture without/with viscous fluid dampers are established. The field measurement is carried out to verify the analytical FE model and determine the damping ratios of the example transmission tower-line system. The dynamic analysis of the tower-line system is carried out to investigate structural performance under cable rupture and the validity of the proposed control approach based on viscous fluid dampers is examined. The made observations demonstrate that cable rupture may induce strong structural vibration and the implementation of viscous fluid dampers with optimal parameters can effectively suppress structural responses.

Design of a laboratory-scale superconducting DC transmission line (모델급 초전도 직류 송전 선로의 설계)

  • Kim, Sung-Kyu;Dinh, Minh-Chau;Park, Minwon;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • pp.1102-1103
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    • 2015
  • The researchers worldwide have been trying to apply high temperature superconducting wire for power system devices. High voltage direct current (HVDC) transmission system has been used for bulk and long-distance power transmission. The authors designed a laboratory-scale superconducting DC transmission line to investigate its applicability to an HVDC system. The superconducting DC transmission line was simulated in connection to a laboratory-scale HVDC system using PSCAD/EMTDC. The operating characteristics of the superconducting DC transmission line connected to HVDC system and the effects of the superconducting DC transmission line on HVDC system were analyzed and compared with the results of a conventional DC transmission line. The results of operating characteristics for the superconducting DC transmission line were discussed in detail.

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A Study on Basic Characteristics of a Coplanar-type Transmission Line Employing Periodic Structure on Si RFIC (Si RFIC상에서 주기적 구조를 이용한 코프레너형 전송선로의 기본특성연구)

  • Joh, Han-Nah;Park, Young-Bae;Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.6
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    • pp.964-973
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    • 2008
  • In this study, a short-wavelength coplanar-type transmission line employing periodic ground structure (PGS) was developed for application to miniaturized on-chip passive component on Si Radio Frequency Integrated Circuit (RFIC). The transmission line employing PGS showed shorter wavelength and lower characteristic impedance than conventional coplanar-type transmission line. The wavelength of the transmission line employing PGS structure was 57 % of the conventional coplanar-type transmission line on Si substrate. Using the theoretical analysis. basic characteristics of the transmission line employing PGS (e.g., bandwidth. loss, impedance, and resonance characteristics) were also investigated in order to evaluate its suitability for application to a development of miniaturized passive on-chip components on silicon RFIC. According to the results. the bandwidth of the transmission line employing PGS was more than 895 GHz as long as T is less than 20${\mu}m$, and the resonance characteristic was observed in 1239 GHz, which indicates that the PPGM structure is a promising candidate for application to a development of miniaturized on-chip passive components on Si RFIC.