Radial distribution of the electrical characteristics of HV XLPE insulated cables was investigated with respect to EEA or EBA oligomers migration into the insulation. During processing and aging, the migration of low molecular weight fractions of EEA or EBA copolymers used in semiconductive compounds gives rise to an increase of tan delta close to the semiconductive shields, and to a decrease of AC and DC breakdown strengths. However, this migration seems to increase the impulse breakdown strength, and to avoid bow-tie trees development.
展开▼
