The Experts below are selected from a list of 11226 Experts worldwide ranked by ideXlab platform

D.a. Horvath - One of the best experts on this subject based on the ideXlab platform.

  • Preliminary results of Electric Insulation void content growth from simulated exposure to a nuclear power plant's high energy line break event
    2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.01CH37225), 2001
    Co-Authors: D.a. Horvath, D. C. Martin
    Abstract:

    A need exists to confirm the remaining life of Electric cable used in nuclear power stations. Remaining life must include margins for surviving the potential harsh environment effects of a design basis event (DBE) after up to 60 years of normal operation. Typically a DBE would be a postulated break in the largest high temperature pressurized line leading to elevated temperatures (accelerated aging conditions) in the surrounding environment. Previous research has shown that void content within polyolefin Electric Insulation grows during normal thermal aging and that oxygen diffusion plays a role in this growth. Under accelerated aging conditions, oxygen diffusion is limited reducing chemical reaction rates, and potentially affecting the aging process. This paper discusses preliminary experimental results indicative of accelerated aging for three commonly used polyolefin materials. Each sample was re-examined after thermal annealing for 17 hours at 120 C. Results indicate the void content increased dramatically from the pre-aged sample values

  • Relationship of Electric Insulation void content with Electric cable normalized capacitance
    2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.01CH37225), 1
    Co-Authors: D.a. Horvath, R.l. Steinman
    Abstract:

    For aging nuclear power stations and other facilities, a need exists for monitoring aging degradation effects in Electric cable Insulation. Our current research efforts are pursuing a non-destructive in situ approach for determining remaining life of cable Insulation through detection of real time age-dependent void characteristics and comparison to known end of life void parameters. In many cases, a critical cable may be inaccessible because of location within conduits, in concrete, or underground making void detection impractical. This paper reports on initial efforts to correlate our void detection approach to a technique proposed by Chang-Liao et al.(ANS NPIC&HMIT, Nov. 2000), which appears to be promising for inaccessible cable. This paper postulates that the detected change in capacitance reported by Chang-Liao et al. is related to the void growth that occurs with aging and discusses a possible correlation between ionized void content (caused by the applied dc potential) and the value of capacitance.

Hae Jong Kim - One of the best experts on this subject based on the ideXlab platform.

  • Study on Electric Insulation properties for development of conduction-cooled HTS SMES
    Cryogenics, 2007
    Co-Authors: J.h. Choi, Hae Jong Kim, Dong Sup Kwag, H.g. Cheon, Ki-chul Seong, Mun-soo Yun, Sang-hyun Kim
    Abstract:

    Abstract The conduction-cooled HTS SMES magnet is operated in high vacuum and cryogenic condition. Thus, Electric Insulation design at high vacuum and cryogenic temperature is a key and important element that should be established to accomplish compact design that is a big advantage of HTS SMES. However, the performance of insulators under cryogenic conditions in air or vacuum is virtually unknown. Therefore, we need active research and development of Insulation concerning application of the conduction-cooled HTS SMES. Specially, this paper will present the results of high vacuum and cryogenic temperature breakdown and flashover discharge characteristics between cryocooler and magnet-coil. The breakdown and surface flashover discharge characteristics are studied at cryogenic temperature and vacuum. Also, some materials such as aluminum nitride (AlN), Al 2 O 3 that have high thermal conduction are taken up and the flashover discharge characteristics are investigated. From the results, we confirmed that basic database on the discharge between cryocooler and magnet-coil was established for the Electric Insulation design.

  • Insulation studies and experimental results for high Tc superconducting power cable
    Applied Superconductivity, IEEE Transactions on, 2005
    Co-Authors: Hae Jong Kim, Jeon Wook Cho, Dong Sup Kwag, Ki Deok Sim
    Abstract:

    In this paper, we studied Electric Insulation characteristics of synthetic Laminated Polypropylene Paper (LPP) in liquid nitrogen (LN2) for the application to high temperature superconducting (HTS) cable. And, we selected the Insulation paper/LN2 composite Insulation type for the Electric Insulation design of a HTS cable. Furthermore, we compared the breakdown characteristics of the butt gap and bent mini-model cable that comes into being in this kind of cryogenic Insulation type. It is necessary to understand the winding parameter of Insulation paper/LN2 composite Insulation.

R.l. Steinman - One of the best experts on this subject based on the ideXlab platform.

  • Relationship of Electric Insulation void content with Electric cable normalized capacitance
    2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.01CH37225), 1
    Co-Authors: D.a. Horvath, R.l. Steinman
    Abstract:

    For aging nuclear power stations and other facilities, a need exists for monitoring aging degradation effects in Electric cable Insulation. Our current research efforts are pursuing a non-destructive in situ approach for determining remaining life of cable Insulation through detection of real time age-dependent void characteristics and comparison to known end of life void parameters. In many cases, a critical cable may be inaccessible because of location within conduits, in concrete, or underground making void detection impractical. This paper reports on initial efforts to correlate our void detection approach to a technique proposed by Chang-Liao et al.(ANS NPIC&HMIT, Nov. 2000), which appears to be promising for inaccessible cable. This paper postulates that the detected change in capacitance reported by Chang-Liao et al. is related to the void growth that occurs with aging and discusses a possible correlation between ionized void content (caused by the applied dc potential) and the value of capacitance.

Atsuhiko Yamanaka - One of the best experts on this subject based on the ideXlab platform.

  • Heat Drain Effects From HTS Tapes to High Thermal Conduction Plastics for Conduction-Cooled Magnets
    IEEE Transactions on Applied Superconductivity, 2007
    Co-Authors: Tomoaki Takao, Akihiro Watanabe, Tomohiro Takiyama, Kazuya Nakamura, Atsuhiko Yamanaka
    Abstract:

    In conduction-cooled HTS magnets, it is important to design effective heat drains from the HTS tapes to a cold head of a refrigerator. Aluminum nitride (AlN) is often used as a heat-drain material because thermal conductivity and Electric Insulation of the material are good. However, the AlN is hard and brittle, and hence it is difficult for magnet makers and users to process the AlN. To address this issue, we have studied to use the plastic having both high-thermal conduction and high-Electric Insulation properties as the heat drain material. The plastic is the Dyneema fiber reinforced plastic (DFRP). We fabricated an experimental arrangement in which the Bi-2223 tape and the DFRP block were contacted, and a steady current was applied to the tape. Based on the measured voltage between terminals, thermal drain properties from the tape to the DFRP block were estimated. In the same conditions, experiments using the glass fiber reinforced plastic (GFRP) were also performed. Furthermore, the coil shape sample made of the AlN and DFRP were used. The paper presents the difference of the thermal drain performance in the AlN, the DFRP and the GFRP.

Dong Sup Kwag - One of the best experts on this subject based on the ideXlab platform.

  • Study on Electric Insulation properties for development of conduction-cooled HTS SMES
    Cryogenics, 2007
    Co-Authors: J.h. Choi, Hae Jong Kim, Dong Sup Kwag, H.g. Cheon, Ki-chul Seong, Mun-soo Yun, Sang-hyun Kim
    Abstract:

    Abstract The conduction-cooled HTS SMES magnet is operated in high vacuum and cryogenic condition. Thus, Electric Insulation design at high vacuum and cryogenic temperature is a key and important element that should be established to accomplish compact design that is a big advantage of HTS SMES. However, the performance of insulators under cryogenic conditions in air or vacuum is virtually unknown. Therefore, we need active research and development of Insulation concerning application of the conduction-cooled HTS SMES. Specially, this paper will present the results of high vacuum and cryogenic temperature breakdown and flashover discharge characteristics between cryocooler and magnet-coil. The breakdown and surface flashover discharge characteristics are studied at cryogenic temperature and vacuum. Also, some materials such as aluminum nitride (AlN), Al 2 O 3 that have high thermal conduction are taken up and the flashover discharge characteristics are investigated. From the results, we confirmed that basic database on the discharge between cryocooler and magnet-coil was established for the Electric Insulation design.

  • Insulation studies and experimental results for high Tc superconducting power cable
    Applied Superconductivity, IEEE Transactions on, 2005
    Co-Authors: Hae Jong Kim, Jeon Wook Cho, Dong Sup Kwag, Ki Deok Sim
    Abstract:

    In this paper, we studied Electric Insulation characteristics of synthetic Laminated Polypropylene Paper (LPP) in liquid nitrogen (LN2) for the application to high temperature superconducting (HTS) cable. And, we selected the Insulation paper/LN2 composite Insulation type for the Electric Insulation design of a HTS cable. Furthermore, we compared the breakdown characteristics of the butt gap and bent mini-model cable that comes into being in this kind of cryogenic Insulation type. It is necessary to understand the winding parameter of Insulation paper/LN2 composite Insulation.