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546 results on '"Hozumi, N."'

1. Space Charge Measurement Method for Model HVDC Cable at High Conductor Temperature

Author

Sumarwoto, Trinurkalid, Morita, S., Kawashima, T., Hozumi, N., Suwarno, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Liang, Qilian, Series Editor, Martin, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, and Németh, Bálint, editor

Published
2020
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4. Feasibility of Space charge measurements on HVDC cable joints

Author

Tzimas, A., Diban, B., Boyer, L., Chen, G., Castellon, J., Chitiris, N., Fothergill, J., Hozumi, N., Kim, Y., Lee, J-H., Mauseth, F., Mazzanti, G., Morshuis, P., Troia, I., Tanaka, Y., and Wu, K.

Subjects
TK
Abstract

This review article aims at illustrating the starting of the activities carried out by the Study Group from the viewpoint of the assessment of the state of the art in the measurement of SC in HVDC extruded cable system joints.

Published
2022

17. Space charge behavior in XLPE cable insulation under 0.2-1.2 MV/cm dc fields

Author

Hozumi, N., Takeda, T., Suzuki, H., and Okamoto, T.

Subjects
Crosslinked polymers -- Research, Polyethylene -- Research, Direct current -- Research, Electric fields -- Research, Electric insulators -- Research, Electric charge and distribution -- Research, Business, Electronics, Electronics and electrical industries
Abstract

This report deals with space charge behavior in PE (polyethylene) under dc fields. Direct observation of time-dependent space charge profiles in 3-mm thick XLPE (crosslinked low-density polyethylene) cable insulation under dc electric fields was performed using the pulsed electroacoustic method. Stable hetero charges were formed when the field was as low as 0.2 MV/cm, and intermittent generation of packet shaped space charges and their propagation through the insulation were observed when the field was as high as 0.7 MV/cm. These phenomena were reproduced in sheet specimens of XLPE and LDPE (low-density polyethylene). It was found that hetero charges resulted from heat treatment of the XLPE specimen containing antioxidant and acetophenone, which is one of the crosslinking by-products, suggesting dissociation of the antioxidant through solvation at high temperature by acetophenone. The packet charges were easily detected when acetophenone was diffused into the LDPE specimen. However, uniformity of acetophenone distribution prevented the packet charge generation. It is suggested on the basis of several experimental results that local ionization of impurities in the insulation through solvation by acetophenone takes place assisted by high field and leads to the packet charge generation. A numerical simulation was carried out based on the above model.

Published
1998

18. Interfacial improvement of XLPE cable insulation at reduced thickness

Author

Tanaka, T., Okamoto, T., Hozumi, N., and Suzuki, K.

Subjects
Electrical cables -- Research, Electric insulators -- Research, Crosslinked polymers -- Usage, Polyethylene -- Usage, Business, Electronics, Electronics and electrical industries
Abstract

An interfacial diffusion method was devised to reduce insulation thickness by improving the interfacial properties of XLPE cable insulation. This method is based on a proposed concept of the facilitation of oriented lamellar growth at the interface by addition of special ingredients to the semiconducting layer, which would diffuse into polyethylene in the three layer simultaneous extrusion process for cable manufacture. Diffusion of the ingredients would facilitate lamellae to grow perpendicularly to the semiconducting layers, as predicted theoretically from a free energy model. It was clarified experimentally that oriented lamellar growth would increase the breakdown strength of XLPE insulation. It is suggested the XLPE cables manufactured by this method could be reduced in thickness especially for extra-high voltage, or the cable could be upgraded from 66 to 154 kV as the insulation thickness remains 9 mm.

Published
1996

21. Direct observation of time-dependent space charge profiles in XLPE cable under high electric fields

Author

Hozumi, N., Suzuki, H., Okamoto, T., Watanabe, K., and Watanabe, A.

Subjects
Electrical cables -- Insulation, Electric fields -- Research, Electric charge and distribution -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Space charge distribution was measured, applying an electric field of > 1 MV/cm to 3 mm thick XLPE cable insulation. Improving the conventional pulse electro-acoustic method, a new method was developed to measure space charge when applying HV to cables. Under high field, hetero charges were formed soon after voltage application, followed by an injection from the cathode. Then intermittent injections of charge packets from the anode took place. The space charge distribution kept changing without becoming stabilized. A simulation was done assuming hysteresis of the injection characteristics. The observed intermittent injection near the anode was qualitatively reproduced using computer simulation.

Published
1994

22. Discrimination of partial discharge patterns using a neural network

Author

Hozumi, N., Okamoto, T., and Imajo, T.

Subjects
Electric discharges -- Detection, Neural networks -- Usage, Electric testing -- Innovations, Business, Engineering and manufacturing industries, Science and technology
Abstract

This paper describes the application of the neural network algorithm to the perception of partial discharge patterns. Needle shaped void samples, made from epoxy resin, were used to generate an electrical tree under ac voltage. The partial discharge patterns before and after the tree initiation were learned by the neural network using the back-propagation method. After the learning process was over, unknown discharge patterns were put into the network. It was shown that the network discriminates the tree initiation well. For the stable discrimination of tree initiation, it was required that the tree length be larger than the length of the void.

Published
1992

29. The insulation of HVDC extruded cable system joints. Part 2: Proposal of a new AC voltage PD measurement protocol for quality control during routine tests

Author

Mazzanti, G., primary, Castellon, J., additional, Chen, G., additional, Fothergill, J. C., additional, Fu, M., additional, Hozumi, N., additional, Lee, J. H., additional, Li, J., additional, Marzinotto, M., additional, Mauseth, F., additional, Morshuis, P., additional, Reed, C., additional, Troia, I., additional, Tzimas, A., additional, and Wu, K., additional

Published
2019
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30. The insulation of HVDC extruded cable system joints. Part 1: Review of materials, design and testing procedures

Author

Mazzanti, G., primary, Castellon, J., additional, Chen, G., additional, Fothergill, J.C., additional, Fu, M., additional, Hozumi, N., additional, Lee, J. H., additional, Li, J., additional, Marzinotto, M., additional, Mauseth, F., additional, Morshuis, P., additional, Reed, C., additional, Troia, I., additional, Tzimas, A., additional, and Wu, K., additional

Published
2019
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32. Recommended Practice For Space Charge Measurements In High Voltage Direct Current Extruded Cables For Rated Voltages Up To 550 kV

Author

Mazzanti, G., Marzinotto, M., Castellon, J., Chen, G., Fothergill, J., Fu, M., Hozumi, N., Lee, J.-H., Li, J., Mauseth, F., Morshuis, P., Reed, C., Tanaka, Y., Tzimas, A., Wu, K., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe énergie et matériaux (GEM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Department of Computer Science and Engineering, SangMyung University [Seoul], Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and EEE Standard Association (IEEE-SA), IEEE Std 1732™

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2017

35. Partial Discharge Measurement for Power Cable under Different Installation Conditions and Fabrication of Simple Monitoring Device.

Author

Nhet Ra, Sabihah, N., Kawashima, T., Murakami, Y., and Hozumi, N.

Subjects
PARTIAL discharge measurement, PARTIAL discharges, ELECTRODES, TELECOMMUNICATION cables, CAPACITORS
Abstract

Partial discharge (PD) is considered as one of the major problem which harms the insulation of power cable. The authors have been developing a new measurement method for measuring PD in long-distance cable line using capacitive coupling electrodes. In this method, the PD signal was detected by the newly proposed capacitive coupling electrodes between a shielding layer and an additional foil electrode. In this paper, firstly, the proposed method was applied to detect PD using a communication cable line and the sensitivity was determined as 100 pC. Secondly, a simple PD monitoring device was fabricated using a pulse counter and the performance was satisfactory. Finally, an attempt has been made to understand the effect of the coupling capacitor on detection intensity. Also, the PD detection sensitivity for power cable under different installation conditions was analyzed. [ABSTRACT FROM AUTHOR]

Published
2019
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41. Diagnostics and Accelerated Life Endurance Testing of Polymeric Materials for HVDC Application

Author

Montanari, G. C., Morshuis, P. H. F., Franchi, S., Tanaka, Y., Chen, G., Person, T., Castellon, J., Lee, J.‐H., Ildstad, E., Hozumi, N., Kieffel, Y., Cherukupalli, S., Reed, C., Densley, J., Sutton, S., Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe énergie et matériaux (GEM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), GE Grid Solutions, ARC, Villeurbanne, France, and Cigre Technical Brochure 636, Working Group D1.23

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2015

49. In Memorian [Professor John Tanaka]

Author

Ohki, Yoshimichi, primary, Takada, T., additional, Tanaka, T., additional, Kawamura, K., additional, Kudo, K., additional, Mio, K., additional, Kimura, K., additional, Hozumi, N., additional, and Homma, H., additional

Published
2012
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