Discharging micro cavities and electric field enhancement

due to cavities in HVDC XLPE cables

This paper presents simulation and calculation results of electric field enhancement due to various cavity shapes carried out on polymeric high voltage direct current (HVDC) cables. Two aspects are considered: partial discharges (PD) in microcavities and field enhancement factor under DC. PD can occur within defects already existing inside crosslinked polyethylene (XLPE) matrix under various conditions. These conditions are well known under alternative current (AC) but not so well under DC and DC with harmonics. Charges accumulation at XLPE/void interfaces may be responsible for local field enhancement and discharges. Aim of this investigation is to identify if these effects once combined can increase microvoids volume into micrometer size. Keywords— HVDC XLPE cables; microcavity; electric field distribution; partial discharges

P. Daniel, P. RAIN, O. GALLOT-LAVALLEE, S. HALLER

Conference: SFE 2018