Insulation diagnosis of ۶۳kV cross-linkedpolyethylene (XLPE) power cable based on dielectricresponse theory

The insulation diagnosis of power cable is animportant way to evaluate the aging degree of power cable. Inrecent years, the latest development ofpolarization/depolarization current (PDC) method can effectivelyreflect the overall dielectric ageing state. This paper studies thepolarization/depolarization current characteristics of the powercable under different aging conditions and analyzes therelationship between current characteristics and aging degree.This paper first discusses the dielectric response theory ofpolarization/depolarization, and set up the cable aging andpolarization/depolarization current testing plan. The equivalentmodel of three branches circuit is proposed based on themeasured results, further analysis of the frequency response ofthe cable is discussed. The research shows that the tangent(tanδ(ω)) of the aging cable and the new cable has a significantdifference in the low frequency range, which can be used tocharacterize the aging degree of cable insulation.

Keywords:

polarization , depolarization , dielectric response , crosslinked-polyethylene , power cable , insulation diagnosis