抄録
Space charge in full size ±250kV DC cables was measured using the pulse-electroacoustic method. Two types of newly developed DC XLPE cables with 20mm thick insulation were subjected to the measurement under the DC voltage of 500kV keeping the conductor temperature both at the room temperature and at 85°C. Both qualitative analysis on the space charge distribution and the quantitative analysis on the electric fields in the vicinity of semicon interfaces were done. It was shown that the field in the vicinity of the inner semicon tends to increase by 10-40% when the polarity of the applied voltage was switched, in the case when the conductor was kept at 85°C. However, the distortion of the electric field was significantly small compared to that expected with conventional XLPE cables. As the result, the subjected DC cables are considered to have stable DC characteristics from the viewpoint of space charge behavior.
