Successful detection of insulation degradation in cables by frequency domain reflectometry

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

We have succeeded in detecting the degradation of cable’s polymeric insulation well before its continual use becomes risky. Degradation of organic polymers is mainly caused by oxidation if the ambience around the cable contains oxygen. When organic polymers are oxidized, polar carbonyl groups are formed, by which the permittivity is increased. This in turn decreases the characteristic impedance of a polymer-insulated cable. If we inject electromagnetic waves in a very wide frequency range into the cable and measure the ratio of reflected power to injected power, the information on the effects of the characteristic impedance changes is included in the frequency spectra of the ratio. If we do inverse Fourier transform, we can convert the data to a time domain. Therefore, we can know the degraded portion by multiplying the velocity of electromagnetic waves in the cable.

Original languageEnglish
Title of host publicationProceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors
PublisherSpringer International Publishing
Pages77-85
Number of pages9
ISBN (Print)9783319684536
DOIs
Publication statusPublished - 2018 Jan 1
Event18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017 - Portland, United States
Duration: 2017 Aug 132017 Aug 17

Publication series

NameMinerals, Metals and Materials Series
VolumePart F11
ISSN (Print)2367-1181
ISSN (Electronic)2367-1696

Other

Other18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017
CountryUnited States
CityPortland
Period17/8/1317/8/17

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Keywords

  • Aging
  • Cable
  • Characteristic impedance
  • Condition monitoring
  • Fault location
  • Insulation diagnosis
  • Polymeric insulation

ASJC Scopus subject areas

  • Metals and Alloys
  • Materials Chemistry
  • Electronic, Optical and Magnetic Materials
  • Mechanics of Materials
  • Energy Engineering and Power Technology

Cite this

Ohki, Y., & Hirai, N. (2018). Successful detection of insulation degradation in cables by frequency domain reflectometry. In Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors (pp. 77-85). (Minerals, Metals and Materials Series; Vol. Part F11). Springer International Publishing. https://doi.org/10.1007/978-3-319-68454-3_7