Title :
Thermal ageing in polymer cables: effect of interfaces on dielectric properties
Author :
Brincourt, T. ; Pinel, B. ; Morra, R.M. ; Braun, J.M.
Author_Institution :
Direction des Etudes et Recherches, Electr. de France, Paris, France
Abstract :
EPR (ethylene propylene rubber)/CSPE (chlorosulfonated polyethylene) control and safety system cables are used in nuclear plants in France. As part of a continuing plant life assurance program, diagnostic tests for these cables are being developed. In order to evaluate the ageing of plant cables, low frequency (10-4-10 4 Hz) dielectric measurements have been investigated to probe chemical as well as physical properties of insulation materials. Several artificially aged cable samples with controlled formulations show a shift in the frequency of maximum dielectric absorption with ageing when tested in the laboratory. This effect is shown to be caused by interfacial phenomena between the cable layers and is dominated by the dielectric properties of CSPE whose conductivity drastically increases with thermal ageing. The release of chlorinated species appears to be responsible for this change in conductivity
Keywords :
ageing; cable insulation; dielectric measurement; insulation testing; nuclear power stations; polymer insulators; safety systems; France; artificially aged cable; chemical properties; chlorinated species; chlorosulfonated polyethylene; conductivity change; control; diagnostic tests; dielectric absorption; dielectric measurements; dielectric properties; ethylene propylene rubber; interfaces; interfacial phenomena; life assurance program; nuclear plants; physical properties; polymer cables; safety system; thermal ageing; Aging; Cables; Control systems; Dielectrics; Frequency; Paramagnetic resonance; Polyethylene; Polymers; Rubber; Thermal conductivity;
Conference_Titel :
Electrical Insulation, 1994., Conference Record of the 1994 IEEE International Symposium on
Conference_Location :
Pittsburgh, PA
Print_ISBN :
0-7803-1942-7
DOI :
10.1109/ELINSL.1994.401419
