抄録
DC leakage current measurements have been carried out regularly to diagnose the insulation of XLPE cables. The degree of the deterioration of the cable insulation is determined by the DC leakage current value. On the measurement at the installation of XLPE cables, the DC leakage current sometimes shows a large value with a peak. To clarify the causes of the DC leakage current peak, we investigated the DC leakage current of 6.6kV dry-cured XLPE cables at different temperatures. The results show that the residue of the crosslinking reaction influences the peak of the DC leakage current. To discuss mechanism of the peak, we also measured the DC leakage current repeatedly at the same cable, and investigated the space charge distribution in the cable insulation by the Pulsed Electroacoustic Method. It is expected that the DC leakage current peak depends on the space charge relative to the residue.
