Temperature effect on space charge dynamics in multi-layer insulation Fluorinated Ethylene Propylene (FEP) Low Density Polyethylene (LDPE)

Abstract

Space charge behavior at dielectric interfaces in multi-layer Fluorinated Ethylene Propylene (FEP) and Low Density Polyethylene (LDPE) subjected to a dc field has been investigated as a function of the temperature using the pulsed electro acoustic (PEA) technique.A sandwich structure constituted by two dielectric films not identical FEP/LDPE was used to study the charging propensity of electrode/dielectric and dielectric/ dielectric interface. The time dependence of the space charge distribution was subsequently recorded at different temperature under field (polarization) and short circuit condition (depolarization). Experimental results demonstrated that charge injected process take place in all cases. However it is shown that the amount of interfacial charge depends drastically on the temperature. It has greater influence on the distribution, injection and mobility of space charge in the bulk and at dielectric/ dielectric interfaces.

Feasibility of Space Charge Measurements on HVDC Cable Joints: Study Group—IEEE DEIS Technical Committee “HVDC Cable and Systems:”

“…Other studies investigated space charge distribution in sandwich-structured nanocomposites and the effect of insulations or nanocomposites interfaces on space charge injection, accumulation and traps. [52,53,54,55].…”

Space Charge Behavior of Thermally Aged Polyethylene Insulation of Track Cables

“…Loads of work have been carried out to characterize single-layer insulation’s space charge behavior and analyze the internal trap characteristics under thermal aging condition [ 17 ]. Dakka et al [ 18 ] measured the space charge characteristics of crosslinked polyethylene (XLPE) materials and found that in the first few hours of thermal aging, the accumulation rate of space charge was related to the breakdown time of the insulation layer. The higher the initial charge accumulation, the shorter the insulation failure time.…”