TY - GEN
T1 - Successful detection of insulation degradation in cables by frequency domain reflectometry
AU - Ohki, Yoshimichi
AU - Hirai, Naoshi
N1 - Funding Information:
This research was partly supported by the Nuclear Regulation Authority in Japan as a part of the Ageing Management Program for System Safety.
Publisher Copyright:
© The Minerals, Metals & Materials Society 2018.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
KW - Aging
KW - Cable
KW - Characteristic impedance
KW - Condition monitoring
KW - Fault location
KW - Insulation diagnosis
KW - Polymeric insulation
UR - http://www.scopus.com/inward/record.url?scp=85042408867&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042408867&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-68454-3_7
DO - 10.1007/978-3-319-68454-3_7
M3 - Conference contribution
AN - SCOPUS:85042408867
SN - 9783319684536
T3 - Minerals, Metals and Materials Series
SP - 77
EP - 85
BT - Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors
A2 - Wright, Michael
A2 - Paraventi, Denise
A2 - Jackson, John H.
PB - Springer International Publishing
T2 - 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017
Y2 - 13 August 2017 through 17 August 2017
ER -