• 제목/요약/키워드: OF Cable

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케이블 포설장력 특성에 대한 실험적 고찰 (The experimental investigation on the characteristics of the cabling tension)

  • 김동훈;한진우
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.49-53
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    • 2009
  • If you are installing communications cables in the pipeline based on the kind of cable installation tension within the allowed range of the tension must be maintained. The tension of the installation affected by the cable types, cable jacketed status, cross-sectional shape of the pipeline, the substance present in the pipeline, pipeline linear, the direction of the cable is installed. Depending on the size of the cable installation tension fatal influence on the quality of communication, or, at worst, the cable can be cut. In this paper, test bed for building a pipeline and using optical cable and such cable tension was measured. Freedom of access to the pipeline used in the experiment, and installed in conjunction with the cable tension was measured. It possible for the cable installation to determine whether a duplicate, and have compared the actual measured tension value and the theoretical expression.

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고온초전도 케이블의 과도상태 특성 연구 (Study of Transient Characteristics of High Temperature Superconducting Cable)

  • 장현만;이창영;김춘동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.697-699
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    • 2005
  • High temperature superconducting (HTS) cable could be regarded as one of the most promising technologies for large electric power delivery with high reliability and low losses of power transmission system. Therefore, since 2001, LS Cable Ltd. has been developing 22.9kV, 50MVA HTS cable system as a member of DAPAS (Dream for Advanced rower system by Applied Superconductivity technology) program. In 2003, 22.9kV HTS cable system, single-core cable employing BSCCO HTS wires was firstly manufactured in 2003, and then three-core cable was also successfully developed through the demonstration of its field applicability. In this paper, based on these experiences, the relevant design technology and transient characteristics of HTS cable is described.

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끌줄 및 부이줄에 있어서 Pode 해석에 의한 줄 함수의 이용 (use of Cable Functions by Pode's Analysis in a Towing Cable or a Buoy Cable)

  • 박해훈
    • 수산해양기술연구
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    • 제35권4호
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    • pp.353-358
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    • 1999
  • Tabulated results by Pode are used for computing the cable shape and cable tension in static equilibrium. This paper describes a technique using the integral form by Pode to give a simplified calculation of the cable functions at any desired value because in most practical cased the points of interest on the cable are not the points of reference on which the tables are based. Solving the nondimentional tension, $\tau$, defined by Pode in closed form reduces the integral in cable functions to a single integral. The technique using the integral form enables us to calculate the cable functionsin at any critical angle and at any point in case of a towing cable or certain cable-buoy systems.

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RF 감지 방식 on-line 케이블 접속재 진단 (On-line Test Equipment for Cable Joint by RF Sensing)

  • 이왕하;이성희;정희돈;김덕규;이동영
    • 대한전기학회논문지:전력기술부문A
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    • 제52권11호
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    • pp.661-667
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    • 2003
  • It has little possibility that a cable causes any problem in electric power facilities. But when a trouble occurs in cable or cable joint, the damage is very severe. The main causes of the cable defections are bad cable making procedure, poor cable operation and deterioration according to the years. There are some cases to have potential problems due to many cable connection points, because of short length of cable, especially in 154㎸ system. In this study, novel method to measure partial discharge in cable joints is proposed and the effectiveness and the reliability of the proposed method is shown through experiment results of field.

Theoretical investigation on rain-wind induced vibration of a continuous stay cable with given rivulet motion

  • Li, Shouying;Chen, Zhengqing;Li, Shouke
    • Wind and Structures
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    • 제19권5호
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    • pp.481-503
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    • 2014
  • A new theoretical model on rain-wind induced vibration (RWIV) of a continuous stay cable is developed in this paper. Different from the existing theoretical analyses in which the cable was modeled as a segmental rigid element, the proposed scheme focuses on the in-plane and out-of-plane responses of a continuous stay cable, which is identical with the prototype cable on cable-stayed bridge. In order to simplify the complexities, the motion law of the rivulet on the cable surface is assumed as a sinusoidal way according to some results obtained from wind tunnel tests. Quasi-steady theory is utilized to determine the aerodynamic forces on the cable. Equations of motion of the cable are derived in a Cartesian Coordinate System and solved by using finite difference method to obtain the in-plane and out-of-plane responses of the cable. The results show that limited cable amplitudes are achieved within a limited range of wind velocity, which is a unique characteristic of RWIV of stay cable. It appears that the in-plane cable amplitude is much larger than the out-of-plane cable amplitude. Rivulet frequency, rivulet distribution along cable axis, and mean wind velocity profile, all have significant effects on the RWIV responses of the prototype stay cable. The effects of damping ratio on RWIVs of stay cables are carefully investigated, which suggests that damping ratio of 1% is needed to well mitigate RWIVs of prototype stay cables.

사장교 케이블 단면적의 점진적 최적화에 관한 연구 (A study on the Evolutionary Optimization of Cable Area of the Cable-Stayed Bridge)

  • 최창근;이태열;홍현석;김은성
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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    • pp.113-120
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    • 1996
  • This study presents the optimization technique to determine the cable areas of the cable-stayed bridge. The optimization method presented in this paper is based on an evolutionary procedure, in which the area of high stressed cable is increased step-by-step until an optimal area of the cable is obtained. A comparison between the maximum values of the present method and those of the cable-stayed bridge that has the same cable area shows the advantages of the present method.

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초전도케이블 시장진입 가격 산정 방법론 고찰 (Methodology for Estimating the HTS Cable Market Price)

  • 김종율;이승렬;윤재영
    • 대한전기학회논문지:전력기술부문A
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    • 제53권10호
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    • pp.536-541
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    • 2004
  • As power demand increases gradually, the call for underground transmission system increases. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable has the several useful characteristics such as increased power density, stronger magnetic fields and/or reduced losses. Therefore HTS cable can allow more power to be moved in existing ducts, which means very large economical and environmental benefits. In these days, companies world-wide have conducted researches on HTS cable. A development project for a 22.9kV class HTS cable is proceeding at a research center and university in Korea. In this paper, we investigate the expected price of HTS cable to have a merit in viewpoint of economic aspect. First, life-cycle cost of conventional cable is calculated and based on this, the expected price of HTS cable is evaluated, which HTS cable is competitive against conventional cable.

Cable with discrete negative stiffness device and viscous damper: passive realization and general characteristics

  • Chen, Lin;Sun, Limin;Nagarajaiah, Satish
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.627-643
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    • 2015
  • Negative stiffness, previously emulated by active or semi-active control for cable vibration mitigation, is realized passively using a self-contained highly compressed spring, the negative stiffness device (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage, enables increment of damper deformation during cable vibrations and hence increases the attainable cable damping. Considering the small cable displacement at the damper location, even with the weakening device, the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thus been conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependent negative stiffness is further accounted by numerical analysis, validating the accuracy of the linear approximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practical and cost-effective solution to improve the modal damping of a cable provided by an external damper, especially for super-long cables where the damper location is particularly limited. Moreover, mathematically, a linear negative stiffness and viscous damping assembly has proven capability to represent active or semi-active control for simplified cable vibration analysis as reported in the literature, while in these studies only the assembly located near cable anchorage has been addressed. It is of considerable interest to understand the general characteristics of a cable with the assembly relieving the location restriction, since it is quite practical to have an active controller installed at arbitrary location along the cable span such as by hanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutions with respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable with a viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complex frequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptive passive or semi-active or active device for cable vibration control.

Feasibility study on the inductive fault current limiting cable

  • Lee, Sang Yoon;Choi, Jongho;Kim, Dong Min;Sim, Kideok;Cho, Jeonwook;Kim, Seokho
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권3호
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    • pp.24-28
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    • 2013
  • Fault current limiting (FCL) cable is a kind of superconducting cable which has a function of limiting the fault current at the fault of power grid. The superconducting cable detours the fault current through its stabilizer to keep the temperature as low as possible. On the other hands, the FCL cable permits the temperature rise within some acceptable limit and the fault current is limited by the consequent increase of the resistance of superconducting cable. This kind of FCL cable is called 'resistive FCL cable' because it uses resistive impedance to limit the fault current. In this paper, we suggest a novel concept of FCL cable, which is named as 'inductive FCL cable'. The inductive FCL cable is similar as the magnetic shielding fault current limiter in its operating mechanism. The magnetic field of superconducting cable is almost perfectly shielded by the induced current at the shielding layer during its normal operation. However, at the fault condition, quench occurs at the shielding layer by the induced current higher than its critical current and the magnetic field is spread out of the shielding layer. It will induce additional inductive impedance to the superconducting cable and the inductive impedance can be increased more by installing some material with high magnetic susceptibility around the superconducting cable. We examined the feasibility of inductive FCL cable with simple elemental experiments. The current limiting performance of inductive FCL cable was estimated considering an arbitrary power grid and its fault condition.

케이블 니팅의 표현 유형에 관한 연구 (A Study on the Expression Types of Cable Knitting)

  • 김성달
    • 패션비즈니스
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    • 제22권5호
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    • pp.41-51
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    • 2018
  • Cable knitting, one of the most representative structures of knitwear has been applied to a number of knit items in a variety of expressions every season. The purpose of this study is to analyze the various types of expressions applied with cable knitting techniques to make the necessary data for planning cable knit designs. The types of cable knitting were devide into two categories which are based on the cable knitting pattern and structure. Based on the pattern, firstly, formal type is a reproduction of traditional Aran knit style and is usually applied to a practical and comfortable timeless knit product. Secondly, informal type is irregular applied to patterns and directions to highlight the dynamics of cable patterns. Thirdly, contrasting type emphasizes the cable pattern by contrasting the color of the part of the cable pattern. Fourthly, figurative type is the expression of the conceptual motifs and using the cable knit pattern itself as motif. Based on the structure, firstly, open type is to emphasize patterns and spaces by utilizing open spaces created by the intersection of cabling stitches. Secondly, decorative type is to enhance the ornamental effect of cable knitting by various methods and other subsidiary materials. Thirdly, avant-garde type is applied in various ways with exaggerated volumes or textures using the three-dimensional effects of cable knitting. Through this study, we look forward to the possibility of expressing the unique aesthetic characteristics of each of the various knitting techniques.