Conductivity Characteristics of High Voltage Cable Buffer Layer under Pressure

HV cables are the key components in urban power transmission system. The semi-conductive water-blocking buffer layer of HV cable has gained more and more attention due to the ablation defects. Therefore, the conductivity characteristics which are directly related to the ablation defect are studied in this paper. The volume resistivity and the surface resistance of buffer layer samples from two suppliers are tested according to standard JB/T 10259. Furthermore, the volume resistivity and the surface resistance under different pressure applying on the test electrodes are evaluated. Finally, the microstructure of the buffer layer and the conductivity mechanism of carbon-black filled polymer are adopted to explain the obtained conductivity characteristics under pressure.