Partial discharge patterns on cross-linked polyethylene DC power cables

Since electrical energy supply is crucial and HVAC applications play a significant role in that field, work and discussion about PD are mostly related to AC voltage. The situation is different recently because HVDC applications have started to take a part on the electrical energy supply. HVDC cable systems nowadays have been replaced the use of HVAC cable systems for transporting energy over long distances because some advantages it has. Cross-linked polyethylene (XLPE) cables are increasingly taking the place of mass-impregnated (MI) and oil-filled (OF) cables in power transmission because they are easier to maintain and are less likely to cause oil leakage. The number of new installed high voltage XLPE power cable increases because of the increase of the use of XLPE cables. In order to investigate partial discharge (PD) phenomena on a cable, XLPE cables with artificial defects are created and tested under DC voltage. This paper describes the DC voltage partial discharge characteristics for different sources such as surface discharge and void discharge. By comparing new representations of DC PD named “NoDi* Pattern” with conventional “PD magnitude as a function of time”, DC PD patterns can be shown and discussed.