DocumentCode :
1338170
Title :
Space charge behavior in XLPE cable insulation under 0.2-1.2 MV/cm dc fields
Author :
Hozumi, N. ; Takeda, T. ; Suzuki, H. ; Okamoto, T.
Author_Institution :
Central Res. Inst. of Electr. Power Ind., Yokosuka, Japan
Volume :
5
Issue :
1
fYear :
1998
fDate :
2/1/1998 12:00:00 AM
Firstpage :
82
Lastpage :
90
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
Keywords :
XLPE insulation; power cable insulation; space charge; DC electric field; LDPE; XLPE cable insulation; acetophenone; antioxidant; crosslinked low-density polyethylene; crosslinking by-product; diffusion; dissociation; heat treatment; hetero charge; high temperature solvation; impurity ionization; numerical simulation; packet charge; pulsed electroacoustic method; sheet specimen; space charge; Acoustic measurements; Acoustic pulses; Cable insulation; Cables; Charge measurement; Current measurement; Density measurement; Polyethylene; Pulse measurements; Space charge;
fLanguage :
English
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
Publisher :
ieee
ISSN :
1070-9878
Type :
jour
DOI :
10.1109/94.660776
Filename :
660776
Link To Document :
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