Distribution Characteristics of Insulation Interfacial Defects in High Voltage Direct Current Cables

In urban power grids, the use of high voltage direct current (HVDC) cables is increasing. Cross-linked polyethylene (XLPE) cables, with its outstanding electrical and mechanical properties, have become the major cables currently produced and used in China. Defects in cables will directly affect the electric filed distribution, which can affect normal operation of cables and bring potential safety problems. In this paper, the distribution characteristic of defect (protrusion on insulation/inner shield interface) and its effect on electric field distribution in 500kV XLPE direct current (DC) cables are discussed in detail.