| 摘要 |
PROBLEM TO BE SOLVED: To enhance dielectric strength by including conducting particles, having a Fermi level of a specified value or less in a semiconductor layer formed with an insulator on a conductor together. SOLUTION: An inner semiconductor layer 11, an insulator 13, an outer semiconductor layer 14, and a sheath 15 are laminated in order on a conductor 10 to form a single core DC cable. The inner semiconductor layer 11 and the outer semiconductor layer 14 are formed by dispersing conducting particles having a Fermi level of 4.0 eV or less in an ethylene family polymer and have a volume resistivity of about 10<3> -10<5>Ω.cm at 25 deg.C. The conducting particles are made of Al, Ag, Mg, or Ca, have preferably a mean particle size of 2-10μm, and a content of 25-50 wt.% so as to stabilize conductivity and make the formation of projections difficult. When a DC voltage is applied, the pouring charge amount from the inner and outer semiconductor layers 11, 14 containing the conducting particles is increased, and hetero space charges produced by ionic impurities in the insulator 13 such as crosslinked polyethylene or the like are cancelled more.
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