Demands of Dielectric Testing of HVAC and HVDC Power Cables with Extruded Insulation

Dielectric testing of extruded HVAC and HVDC cables in the factory or on-site is a challenge when it comes to longer lengths or special applications. Such verification of insulation coordination requires high voltages for quality assurance tests to represent stresses in service like wave shape, partial discharge behavior and dielectric field stress in the insulation medium. Hence, different technical solutions are available to provide the required testing voltage like AC voltage (50/60 Hz or 20…300 Hz), very low frequency voltage (0.01…0.1 Hz) or DC voltage.

Nevertheless, not each test voltage is applicable for all dielectric test requirements due to physical, technical and economical constraints. With regard to the above mentioned facts this contribution will discuss important aspects concerning economical, physical and technical challenges of dielectric testing of extruded HVAC and HVDC cables.