• Title/Summary/Keyword: Semi-conductive compound

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Effect of CNTs on Electrical Properties and Thermal Expansion of Semi-conductive Compounds for EHV Power Cables

  • Jae-Gyu Han;Jae-Shik Lee;Dong-Hak Kim
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.6
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    • pp.603-608
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    • 2023
  • Carbon black with high purity and excellent conductivity is used as a conductive filler in the semiconductive compound for EHV (Extra High Voltage) power cables of 345 kV or higher. When carbon black and CNT (carbon nanotube) are applied together as a conductive filler of a semiconductive compound, stable electrical properties of the semiconductive compound can be maintained even though the amount of conductive filler is significantly reduced. In EHV power cables, since the semi-conductive layer is close to the conductor, stable electrical characteristics are required even under high-temperature conditions caused by heat generated from the conductor. In this study, the theoretical principle that a semiconductive compound applied with carbon black and CNT can maintain excellent electrical properties even under high-temperature conditions was studied. Basically, the conductive fillers dispersed in the matrix form an electrical network. The base polymer and the matrix of the composite, expands by heat under high temperature conditions. Because of this, the electrical network connected by the conductive fillers is weakened. In particular, since the conductive filler has high thermal conductivity, the semiconductive compound causes more thermal expansion. Therefore, the effect of CNT as a conductive filler on the thermal conductivity, thermal expansion coefficient, and volume resistivity of the semiconductive compound was studied. From this result, thermal expansion and composition of the electrical network under high temperature conditions are explained.

Thermal Analysis of Semiconductive Materials (반도전 재료의 열적 특성에 대한 연구)

  • Nam, Jin-Ho;Kim, Woong;Nah, Yeon-Wha
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.223-223
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    • 2007
  • Thermal and mechanical properties were investigated in several semi-conductive materials which is composed of carbon black and polymer. EVA, EEA, and EBA is normally used for matrix polymer and normally acetylene black and furnace black is used. Isothermal thermo gravimetric analysis is done as a function of atmosphere and temperature. In nitrogen atmosphere semicon compound was slowly degradaded but in ambient condition degradaded fast. So in the cable manufacturing, atmosphere and materials are very important.

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The solution for preventing the expansion of cable joint caused by methane($CH_4$) gas to Water proof type of power cable (도체 수밀형 전력케이블의 가교잔사 가스에 의한 직선접속재 부풀음 현상 방지 대책)

  • Kim, Jong-Won;Lee, Ki-Soo;Paek, Heum-Soo;Choi, Bong-Nam;Park, Hee-Cheol
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2020-2022
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    • 2000
  • The cross-linked polyethylene(herein after XLPE) insulated power cable emit the methane($CH_4$)gas in the course of chemical cross-linking process. The general stranded conductor easily discharge this methane gas through the gap of each stranded wires. But the special stranded conductor that filled with semi-conducting rubber compound to prevent water penetration which is applied to water proof type of cable(22.9kV CN/CV-W), disturb the methane gas emission. The pre-mold type cable joint shall be expanded gradually by emit of gas left in XLPE insulation. For example, sometimes the corona problem outbreak on a new power distribution line, resulted from the gap between the sleeve and semi-conductive layer of cable joint. If above mentioned problem especially happened on the way of operating. We have to shut down the line and try to discharge the methane gas in cable joint. In this point, we would like to explain the mechanism of methane gas & cable joint and our test result briefly. At last, we are pleased to introduce the solution for preventing reoccurrence of this problem.

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The Study on Applicability of Semi-conductive Compound for Radioactive Source Tracing Dosimeter in NDT Field (비파괴 검사 분야의 방사성 동위원소 위치추적을 위한 반도체 화합물의 적용 가능성 연구)

  • Shin, Yohan;Han, Moojae;Jung, Jaehoon;Kim, Kyotae;Heo, Yeji;Lee, Deukhee;Cho, Heunglae;Park, Sungkwang
    • Journal of the Korean Society of Radiology
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    • v.13 no.1
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    • pp.39-44
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    • 2019
  • Radiation safety management is being considered very important since radioactive isotopes such as Co-60 and Ir-192 are widely used in fields such as non-destructive test(NDT). In this study, the applicability of Mercury(II) Iodide($HgI_2$) source for tracing system was evaluated. To make sure the unit cell sensor's reliability, we evaluated the electrical properties of the sensor made with $HgI_2$, and then position dependence of the sensor was analyzed and compared with the dose distribution from the planning system. As a result of the evaluation, high reliability of the sensor was shown through the linearity of R-sq > 0.990 and reproducibility of CV < 0.015. In the position dependence evaluation, the maximum value was measured at the isocenter of the sensor and gradually decreased according to the distance. However, the dose distribution data from the planning system was turned out that has difference with that of the sensor up to 30%. This seems to come from the difference between single-point measuring based planning system and area measuring based sensor.

Recycling of Waste XLPE Using a Modular Intermeshing Co-Rotating Twin Screw Extruder (모듈라 치합형 동방향회전 이축 스크류식 압출기를 이용한 폐 XLPE의 재활용)

  • Bang, Dae-Suk;Oh, Soo-Seok;Lee, Jong-Keun
    • Elastomers and Composites
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    • v.39 no.2
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    • pp.131-141
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    • 2004
  • The recycling of waste XLPE(crosslinked polyethylene), which is a major source of scraps from high voltage power transmission cables, has been discussed. The waste XLPE scraps were ground into fine powder with various sizes from less than $100{\mu}m$ up to about $1000{\mu}m$ using two types of tailor-made pulverizers. The compounds were prepared in a modular intermeshing co-rotating twin screw extruder at various conditions such as different compositions, types and powder sizes of waste XLPE, screw configurations and various polymer matrices (LDPE, HDPE, PP, PS). The mechanical and rheological properties and the fracture surface or the compounds were investigated. It was found that an improved impact strength was obtained from the compound with white XLPE powder pulverized from the scraps without outer/inner semi-conductive layers. Generally, the impact strength increases with the content of XLPE but decreases with the size of XLPE. Especially for LDPE, the extrusion was possible up to 80 wt% loading of XLPE. Also, the impact strength increases with the number of kneading disc blocks in the given screw configurations. The melt viscosity of the compounds increases with increasing XLPE loading. However, the higher shear thinning behavior of the compounds at common shear rates implies proper processibility of the compounds. In addition, the impact strength for other polymer matrices used increases with XLPE and it is noticeable that the impact strength of PS/XLPE (80/20 wt%) compound was improved twice that of pure PS.

A Study on the Application of PbI2 Dosimetry for QA in the Electron Beam Therapy (전자선 치료의 선량 측정 QA를 위한 PbI2 선량계 적용 연구)

  • Yang, Seungwoo;Han, Moojae;Jung, Jaehoon;Choi, Yunseon;Cho, Heunglae;Park, Sungkwang
    • Journal of the Korean Society of Radiology
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    • v.14 no.5
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    • pp.517-522
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    • 2020
  • Electron beam have many factors that affect dose distribution, so even if identical settings are used, they should be identified and used for radiation treatment, and the effects on the structures in the body are sensitive, making it difficult to investigate uniform dose distribution on tumors. In this study, a dosimeter was produced using PbI2 which is a photoelectric material, and electrical characteristics were analyzed for 6, 9, and 12 MeV electronics in linear accelerators. The reproducibility test results showed that RSD were 1.1215%, 1.0160%, and 0.05137% respectively at 6, 9, and 12 MeV energies, indicating that the output signals were stable. The linearity evaluation results showed that the R2 values of the reliability indicator for straight line trend lines were 0.9999, 0.9999, and 0.9994, respectively, at 6, 9, and 12 MeV, to confirm that the output signal was proportional to PbI2 as dose increased. The PbI2 dosimeter in this study is judged to be highly applicable to electromagnet measurement and is thought to be able to be used as a basic study of electron detector through photoelectric material.

Study on the Applicability of Semiconductor Compounds for Dose Measurement in Electron Beam Treatment (전자선 치료 분야의 선량 측정을 위한 반도체 화합물의 적용가능성 연구)

  • Yang, Seungwoo;Han, Moojae;Shin, Yohan;Jung, Jaehoon;Choi, Yunseon;Cho, Heunglae;Park, Sungkwang
    • Journal of the Korean Society of Radiology
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    • v.14 no.1
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    • pp.1-6
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    • 2020
  • In this study, it was intended to replace the existing plane parallel ionization chamber, which requires cross-calibration in electron beam treatment. The semiconductor compounds HgI2 was fabricated as detector, and the characteristics of HgI2 detector for the 6, 9 and 12 MeV electron beam was analyzed in the linear accelerator. It was also intended to evaluate the possibility of substitution with existing detectors and their applicability as electron beam dosimetry and to use them as a basic study of the development of electronic beam dosimeter. As a result of reproducibility, RSD was 0.4246%, 0.5054%, and 0.8640% at 6, 9, and 12 MeV energy, respectively, indicating that the output signal was stable. As a result of the linearity, the R2 was 0.9999 at 6 MeV, 0.9996 at 9 MeV, and 0.9997 at 12 MeV showed that the output signal is proportional to HgI2 as the dose is increased. The HgI2 detector of this study is highly applicable to electron beam measurement, and it may be used as a basic research on electron beam detection.