• Title/Summary/Keyword: cable sheath

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Transient Phenomena Analysis of HVDC Submarine Cable (HVDC 해저케이블의 과도현상 해석)

  • Jang, Hwa-Youn;Jeong, Seok-San;An, Chun-Yong;Lee, Jong-Beom
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.490-491
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    • 2011
  • This paper describes the EMTP/ATP Draw modeling HVDC submarine cable. HVDC submarine cables consist of conductor, lead sheath and amore. It is different from general cable which is composed with just conductor and aluminium sheath. Therefore, the transient characteristics are totally different between HVDC submarin cable and general cable. However, the study on HVDC cable modeling and Transient are insufficient. In this paper, characteristic and effectiveness of HVDC Submarine Cable through Transient analysis. Therefore it is evaluated that the application of HVDC Submarine cable at the field should be considered cautiously when more detailed transient analysis, another electrical testes and economic evaluations are implemented.

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Linearity Analysis and Calibration of a Cable-Conduit Bend Sensor (케이블 컨듀잇 굽힘 센서의 선형 특성 분석 및 켈리브레이션)

  • Jeong, Useok;Cho, Kyu-Jin
    • The Journal of Korea Robotics Society
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    • v.12 no.1
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    • pp.26-32
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    • 2017
  • Previous shape sensors including bend sensors and optic fiber based sensors are widely used in various applications including goniometer and surgical robots. But theses sensors have large nonlinearity, limited in the range of sensing curvature, and sometimes are expensive. This study suggests a new concept of bend sensor using cable-conduit which consists of the outer sheath and the inner wire. The outer sheath is made of helical coil whose length of the central line changes as the sheath bends. This length change of the central line can be measured with the length change of the inner cable. The modeling and the experimental results show that the output signal of the proposed sensor is linearly related with the bend angle of the sheath with root mean square error of 5.3% of $450^{\circ}$ sensing range. Also the polynomial calibration of the sensor can decrease the root mean square error to 2.1% of the full sensing range.

Analysis and Reduction Methods of Sheath Circulating Current in Underground Transmission Systems (지중송전계통에서 시스순환전류 해석 및 저감방안)

  • Jeong, Chae-Gyun;Lee, Jong-Beom;Gang, Ji-Won;Jang, Tae-In
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.11
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    • pp.537-545
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    • 2001
  • This paper describes the analysis of sheath circulating current and various methods to reduce the large circulating current in case of operating cable system using EMTP/ATPDraw. And also, possible methods are proposed through a detailed analysis regarding cable systems by considering various electrical and environmental factors. It is evaluated that the proposed reduction methods can be effectively applied to reduce the large sheath circulating over current with the minimized electrical problems.

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Effect analysis of distributed jointing method on underground Transmission Cables (지중송전케이블의 분산식 접속법에 따른 영향 분석)

  • Ha, C.W.;Kim, J.N.
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.148-150
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    • 2002
  • The distributed jointing method is used in the underground tunnel due to narrow space of jointing. This method causes non-uniform length between cable joints. It has an effect on the sheath circulating current and the induced voltage. Furthermore the distributed jointing method may cause transient overvoltage resulting from lightning in underground cable which is connected with overhead line. The author diversely studied the sheath circulating current and induced voltage on underground cable depending on the distributed jointing length under the normal and the transient circumstances. The various simulation results really improve the cable system utility.

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Operation Effectiveness Evaluation According to Conductor Transposition Adoption in Underground Power Cable Systems (지중송전케이블의 도체연가방식 채용시 효용성 평가)

  • Kim, June;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.636-643
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    • 2014
  • Length of most underground power cable in nation is not so long. Therefore it is operated without conductor transposition due to low unbalanced ratio. However, if cable length is long, line constant of each cable will be different. Different line constant can induce unbalanced voltage and current of sheath. Also it can induce several induced interference. This paper describes the operation effectiveness through steady and transient analysis on transposition and untransposition of cable conductor. Especially sheath current and induced voltage are analyzed and compared in case of transposition and untransposition. EMTP is used for modeling and analysis.

A Study of Concentric-Neutral Line Voltage Increase Related by Pole and Cable Joint When Lightening Overvoltage Injected in Combined Distribution Line (혼합 배전선로에 직격낙뢰시 전주와 케이블직선접속재가 케이블 동심중성선 전위상승에 미치는 영향)

  • Jeon, Yong-Joo;Jeon, Myung-Su
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.702-707
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    • 2018
  • In case of Lighting occurs in Domestic combined distribution line, normally the voltage for the neutral line increase dramatically. General connection for underground cable is bundled common earth type so the lightning over voltage increase at the concentric-neutral line is not big enough to give impact on cable sheath. But in case of Non bundled common earth type it is necessary to analyze the phenomena on cable sheath caused by lightening overvoltage. Especially pole and cable joint are the core factor to consider. In this paper concrete pole and cable joint were evaluated in case of Non bundled common earth type combined distribution Line. EMTP simulation model has been designed and several case study were made. Also several experimental test were made to verify the simulation result.

The Characteristics of the Over-current of Shielded Cable and the Fusing Current of Carbon Fiber (탄소섬유의 용단전류 및 차폐 케이블의 과전류 특성)

  • Kim, Young-Seok;Kim, Taek-Hee;Kim, Chong-Min;Shong, Kil-Mok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1761-1766
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    • 2016
  • In this paper, we investigated the fusing current of carbon fiber and thermal properties of carbon fiber and metal shielded cable due to over-current. The fusing current value for the metal-coated carbon fiber was 5.3A in 3K, 7.4K and 13.05A in 12K. And if it exceeds 50% of the fusing current was broken with a rapid voltage rise. In the case of carbon fiber shielded cable, the temperature of the PVC sheath increased somewhat in the allowable current range. However, the temperature of PVC sheath rapidly increased to $128.1^{\circ}C$ in the 2 time allowable current range. This value is $10^{\circ}C$ higher than the temperature of PVC sheath on the metal screen cable, because the resistance of the carbon fiber is high and heat transfer rate is slow.

Impedance Calculation of an Underground Transmission Cable System Installed with a Sheath Current Reduction Device

  • Jung, Chae-Kyun;Lee, Jong-Beom;Kang, Ji-Won;Wang, Xin Heng;Song, Yong Hua
    • KIEE International Transactions on Power Engineering
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    • v.4A no.4
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    • pp.236-242
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    • 2004
  • Previous research results indicated that the designed current reduction device could effectively reduce the sheath circulating current and that its RDP protection device could shield it against both fault and lightning strokes. In this paper, cable impedance is analyzed using wavelet analysis and distance relay algorithm following the installation of these devices so that the operation of distance relay can be estimated. The test results confirm that in these devices, the fault inception angle and SVL bonding types have no impact on the change of cable impedance. In other words, the conventional distance relay can be used without a new relay setting. Thus we can finally assert that the designed current reduction device and its protection device are effective and can be safely installed on the cable transmission system without disturbance.

Study on Property Modification with Fire Retardant Content in the Manufacture of Compounds for Cable Sheath (전선피복용 컴파운드의 제조에서 난연제의 첨가량에 따른 물성 변화 연구)

  • Li, Xiangxu;Lee, Sang Bong;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.3
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    • pp.47-51
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    • 2019
  • The three different polymer compounds were manufactured with the three different fire retardant (silane coated magnesium dihydroxide) contents, 180, 200, 220 phr, for making cable sheath for ship industry. In the research, ethylene-vinylacetate, polyethylene as matrix polymers and ethylene-vinylacetate grafted maleic anhydride as coupling agent were selected for compounding with fire retardant, closslinking agent, plasticizer, and other additives. In the evaluation. ΔT, Mooney viscosity, and tensile strength increased with the content of fire retardant. But it was found that too much fire retardant damaged aging resistance and cold resistance of the polymer compound.

Study on Manufacture and Properties of Polymer Compounds for Cable Sheath (전선피복용 고분자 컴파운드의 제조 및 물성 연구)

  • Li, Xiangxu;Lee, Sang Bong;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.1
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    • pp.42-47
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    • 2019
  • The four different polymer compounds were manufactured to make cable sheath for ship industry. Two kinds of ethylene-vinyl acetate (EVA) were selected as main matrix polymers for compounding with fire retardant, crosslinking agent, filler, plasticizer, and other additives. The properties of the four compounded materials were investigated with the contents of fire retardant, silane coated aluminum hydroxide (S-ATH). Rheology, Mooney viscosity, and tensile strength increased with S-ATH contents by reinforcing effect. With increasing fire retardant amount, fire resistance increased, but cold resistance didn't show an obvious enhancement due to polar effect of vinyl acetate in EVA.