• Title/Summary/Keyword: OF Cable

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Development of HVDC 500kV PPLP MI cable systems in Korea (HVDC 500kV PPLP MI 케이블시스템 개발)

  • Lee, Soo-bong;Cho, Dong-sik;Lee, Tae-ho;Kim, Sung-yun;Lee, Su-kil;Jeon, Seung-ik
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1202-1203
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    • 2015
  • This paper describes the development of HVDC ${\pm}500kV$ polypropylene laminated paper (PPLP) mass-impregnated (MI) type cable system for HVDC transmission lines. As you know, mass-impregnated type cable generally has only insulating layer with the Kraft paper impregnated with a high-viscosity insulating compound. But polypropylene laminated paper is made of a layer of extruded polypropylene (PP) film sandwiched between two layers of Kraft paper. Thanks to PP film and its combination with Kraft paper, PPLP has higher AC, Impulse (Imp.) and DC breakdown (BD) strengths as well as lower dielectric loss than conventional Kraft paper insulation. In addition, Kraft MI cable has a limitation for the maximum conductor temperature as $55^{\circ}C$ But this PPLP MI cable has higher maximum conductor temperature than that of Kraft MI cable due to advantage of oil drainage characteristics. It is the most economic type of cable for HVDC transmission. Also HVDC ${\pm}500kV$ PPLP MI cable system was developed including land joints and outdoor-terminations. In order to prove the mechanical and electrical performances, the type test was carried out according to CIGRE recommendations. A full scale cable system has been tested successfully. And additional load cycle and polarity reversal tests on the cable system showed a higher performance compared with a similar mass impregnated paper cable.

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RTDS-based Model Component Development of a Tri-axial HTS Power Cable and Transient Characteristic Analysis

  • Ha, Sun-Kyoung;Kim, Sung-Kyu;Kim, Jin-Geun;Park, Minwon;Yu, In-Keun;Lee, Sangjin;Kim, Jae-Ho;Sim, Kideok
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2083-2088
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    • 2015
  • The transient characteristics of the tri-axial High Temperature Superconducting (HTS) power cable are different from those of a conventional power cable depending on whether the cable is under a steady or transient state due to the quench. Verification using simulation tools is required to confirm both the characteristics of the cable and the effect of the cable when it is applied to a real utility. However, a component for the cable has not been provided in simulation tools; thus the RTDS-based model component of the tri-axial HTS power cable was developed, and a simulation was performed under the transient state. The considered properties of model component include resistance, reactance and temperature. Simulation results indicate the variation of HTS power cable condition. The results are used for the transient characteristic analysis and stability verification of the tri-axial HTS power cable. In the future, the RTDS-based model component of the cable will be used to implement the hardware-in-the-loop simulation with a protection device.

A Study on the Composition of Superconducting Power Cable Using the Multi-cable (멀티케이블을 이용한 초전도 전력케이블의 구성에 관한 연구)

  • Choi, S.J.;Lee, S.J.;Sim, K.D.;Cho, J.W.;Lee, S.K.;Ko, T.K.
    • Progress in Superconductivity and Cryogenics
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    • v.12 no.1
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    • pp.42-46
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    • 2010
  • The HTS power cable is composed of 2 layers for transmission and 1 layer for shield. The superconducting tapes of transmission layers and shield layer are wound in a cylindrical shape with a winding pitch. The radius of cylinder and the number of superconducting tapes are decided considering to the transmission current capacity and the critical current of superconducting tapes. The increasement of transmission current capacity will increase in volume of HTS cable system. In this paper, the composition method of supercondcuting power cable using the multi-cable is presented. The coated conductor tape can be wound on the smaller cylinder because it has the smaller critical bending diameter than the BSCCO tape. A small-scale cable was composed using the coated conductor tapes and a multi-cable is composed using a small-scale cable considering to transmission current capacity. Even increase of transmission current capacity, this method has advantage that the HTS superconducting power cable can be composed easily. The 22.9 kV and 154 kV superconducting power cable was composed using the presented method.

Tension estimation method using natural frequencies for cable equipped with two dampers

  • Aiko Furukawa;Kenki Goda;Tomohiro Takeichi
    • Structural Monitoring and Maintenance
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    • v.10 no.4
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    • pp.361-379
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    • 2023
  • In cable structure maintenance, particularly for cable-stayed bridges, cable safety assessment relies on estimating cable tension. Conventionally, in Japan, cable tension is estimated from the natural frequencies of the cable using the higher-order vibration method. In recent years, dampers have been installed on cables to reduce cable vibrations. Because the higher-order vibration method is a method for damper-free cables, the damper must be removed to measure the natural frequencies of a cable without a damper. However, cables on some cable-stayed bridges have two dampers: one on the girder side and another on the tower side. Notably, removing and reinstalling the damper on the tower side are considerably more time- and labor-intensive. This paper introduces a tension estimation method for cables with two dampers, using natural frequencies. The proposed method was validated through numerical simulation and experiment. In the numerical tests, without measurement error in the natural frequencies, the maximum estimation error among 100 models was 3.3%. With measurement error of 2%, the average estimation error was within 5%, with a maximum error of 9%. The proposed method has high accuracy because the higher-order vibration method for a damper-free cable still has an estimation error of 5%. The experimental verification emphasizes the importance of accurate damper modeling, highlighting potential discrepancies between existing damper design formula and actual damper behavior. By revising the damper formula, the proposed method achieved accurate cable tension estimation, with a maximum estimation error of approximately 10%.

Mechanical Behavior of Cable Net Structures Considering Sag Ratio (새그 비를 고려한 케이블 네트 구조물의 역학적 거동)

  • Park, Kang-Geun;Lee, Dong-Woo
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.3
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    • pp.47-58
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    • 2016
  • Cable network system is a flexible lightweight structure which curved cables can transmit only tensile forces. The weight of cable roof dramatically can reduce when the length becomes large. The cable network system is too flexible, most cable systems are stabilized by pretension forces. The tensile force of cable system is greatly influenced by the sag ratio and pretension forces. Determining initial sag ratio of cable roof system is essential in a design process of cable structures. Final sag ratio and pretension depends on initial installed sag and on proper handling during installation. The design shape of cable system has an affect on the sag and pretension, and must be determined using well-defined design philosophy. This paper is carried out the comparative data of the deflection and tensile forces on the geometric non-linear analysis of cable network systems according to sag ratio. The study of cable network system is provided to technical informations for the design of a large span cable roof, analytical results are compared with the results of other researchers. Structural nonlinear analysis of systems having cable elements is relatively complex than other rigid structural systems because displacements are large as a reason of flexibility, initial prestress is applied to cables in order to increase the rigidity, and then divergence of nonlinear analysis occurs rather frequently. Therefore, cable network systems do not exhibit a typical nonlinear behavior, iterative method that can handle geometric nonlinearities are necessary.

Comparison Study of Elastic Catenary and Elastic Parabolic Cable Elements for Nonlinear Analysis of Cable-Supported Bridges (케이블교량의 비선형해석을 위한 탄성현수선 및 탄성포물선 케이블요소의 비교연구)

  • Song, Yo Han;Kim, Moon Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5A
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    • pp.361-367
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    • 2011
  • This study introduces an elastic parabolic cable element for initial shaping analysis of cable-supported structures. First, an elastic catenary cable theory is shortly summarized by deriving the compatibility condition and the tangent stiffness matrices of the elastic catenary cable element. Next, the force-deformation relations and the tangent stiffness matrices of the elastic parabolic cable elements are derived and discussed under the assumption that sag configuration under self-weights is small. In addition the equivalent cable tension is defined in the chord-wise direction. Finally, to demonstrate the accuracy of the elastic parabolic cable element, nonlinear relationships of nominal cable tension-chord length and nominal cable tension-tangential stiffness for a single element are presented and compared with results using an elastic catenary cable theory as the slope is varied.

Numerical Simulation of Electro-Mechanical Impedance Response in Cable-Anchor Connection Interlace

  • Nguyen, Khac-Duy;Kim, Jeong-Tae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.1
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    • pp.11-23
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    • 2011
  • In this study, a finite element(FE) analysis on electro-mechanical impedance response of cable-anchor connection interface under various anchor force is presented. In order to achieve the objective, the following approaches are implemented. Firstly, an interface washer coupled with piezoelectric(PZT) material is designed for monitoring cable-force loss. The interface washer is a small aluminum plate on which a PZT patch is surface-bonded. Cable-force loss could be monitored by installing the interface washer between the anchor plate and the anchorage of cable-anchor connection and examining the changes of impedance of the interface washer. Secondly, a FE model for cable-anchor connection is established to examine the effect of cable-force on impedance response of interface washer. Also, the effects of geometrical and material properties of the interface washer on impedance responses under various cable-forces are investigated. Finally, validation of the FE analysis is experimentally evaluated by a lab-scale cable-anchor connection.

Non-linear Dynamic Analysis of Cable Structures Using Elastic Catenary (탄성 현수선 요소를 이용한 케이블 구조물의 비선형 동적해석)

  • Hwang, Jin-Hong;Lee, Sang-Ju;Han, Sang-Eul
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.167-172
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    • 2005
  • In the dynamic analysis of cable structures, geometrical non-linearity due to the flexibility of cables must be considered efficiently. In this paper, formulation of tangent stiffness matrix of elastic catenary cable is derived by using relative nodal displacements, self-weight and unstressed cable length. Free vibration analysis of simply supported cable using elastic catenary cable elements is conducted and compared with that using truss elements. The result shows that elastic catenary cable elements are more compatible than truss elements in the case of analysis of cable structures. Furthermore, the characteristic of dynamic behaviors of cable structures by temporary unstability phenomenon is confirmed.

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