Computer analysis on transient space charge distribution in polymer

This paper presents the computer simulation of the transient space-charge distribution in degassed and non-degassed cross-linked polyethylene (XLPE) which was measured by a pulsed electroacoustic method by Li and Takada (1991). The simulation was made on the transport of both bulk-excited and electrode-injected carriers from anode and cathode by using a hopping model where the trapping and the recombination of the bipolar carriers are also taken into account. The following items are considered in analysis; the bulk-excited carriers, electron injection from the cathode, hole injection from the anode, carrier transport, carrier traps, trap densities and carrier recombination. The simulation was made by fitting the calculated results to the experimental data of the time variation of the space-charge distribution in XLPE. The results show that the carrier trapping and carrier injection are very important factors to explain the time variation of space-charge distribution in degassed and non-degassed XLPE. The cross-linked byproducts increased carrier mobility due to reduced trap site