Influence of moisture on the negative hetero-charge generation in polymeric dielectrics

Author

Sekii, Yasuo ; Maen, Takashi

Author_Institution

Sekii PE Consulting Office, Funabashi, Japan

fYear

2009

fDate

19-23 July 2009

Firstpage

887

Lastpage

890

Abstract

Under DC voltage stress, a negative hetero-charge is generated near the positive electrode in cables insulated with cross-linked polyethylene (XLPE). The generation of negative hetero-charges in XLPE-insulated cable results from cross-linking byproducts, antioxidants, and moisture. Among these inclusions, moisture is known to originate from dehydration of a-methyl styrene, which is a byproduct produced during chemical cross-linking of XLPE cable. To investigate the influence of moisture on negative hetero-charge generation, the authors first studied the moisture absorption of XLPE, EPR, and LDPE. The results show a big difference in moisture absorbing characteristics among XLPE, EPR, and LDPE. The authors next studied the effect of moisture absorption on negative hetero-charge generation in XLPE, EPR, and LDPE. Experimental results demonstrated that the charge densities of negative hetero-charges generated in LDPE and XLPE are proportional to moisture concentration in these materials. The hetero-charge generation mechanism in XLPE is discussed.

Keywords

XLPE insulation; dielectric materials; electrodes; polyethylene insulation; polymers; power cable insulation; DC voltage stress; cables insulation; charge densities; chemical cross-linking; cross-linked polyethylene cable; moisture absorption; negative heterocharge generation mechanism; polymeric dielectrics; positive electrode; Absorption; Cables; DC generators; Dielectrics; Electrodes; Moisture; Paramagnetic resonance; Polymers; Stress; Voltage; EPR; LDPE; XLPE; acetophenone; glycerol-monostearate; moisture; negative hetero-charge;

fLanguage

English

Publisher

ieee

Conference_Titel

Properties and Applications of Dielectric Materials, 2009. ICPADM 2009. IEEE 9th International Conference on the

Conference_Location

Harbin

Print_ISBN

978-1-4244-4367-3

Electronic_ISBN

978-1-4244-4368-0

Type

conf

DOI

10.1109/ICPADM.2009.5252238

Filename

5252238