New Insulating Materials for Next Generation of HVDC Cables - Methods for Evaluation of Degradation Phenomena by Electrical Treeing

Abstract

The ongoing in Sweden research activities aim toelaborate new material concepts that can beapplicable in designing and manufacturing highvoltage direct current (HVDC) cables for very highvoltage levels, up to 800 kV. This task focuses oninvestigating possibilities provided by use ofmaterials containing nanofillers and voltagestabilizers. Variations in breakdown strength,electrical conductivity and control of space chargeswith temperature and composition as well as theirstability during long-term operation are investigated.This paper describes a part of the work thatconcentrates on elaborating a robust methodologyfor testing material resistance to electrical treeinception. It is argued that AC treeing test underramped voltage may effectively be used forscreening candidate materials for applications inHVDC cable insulation