Space charge accumulation and conductivity of crosslinking byproducts soaked LDPE

Abstract

The crosslinking byproducts have significant influences on the electrical performance of the Crosslinked Polyethylene (XLPE). In this paper, the effects of acetophenone, á-methylstyrene and cumyl alcohol on space charge formation and conductivity values have been investigated. The space charge measurement was conducted using Pulse Electroacoustic (PEA) equipment while the conductivity value was determined using the conduction current measurement method. Similar voltages were applied in these two measurements for comparison purpose. From the PEA result, it was clear that these crosslinking byproducts enhance the formation of space charge in LDPE. Homocharges were found in all samples while heterocharges only appear in cumyl alcohol soaked LDPE sample. However, when the applied voltage is removed, the charges in byproducts soaked sample have faster decay compared to the clean sample. Changes in conductivity value were observed when the byproducts present in the LDPE. The charges become more conductive resulting of bigger current flows through the insulator. The result from the space charge and conductivity measurement are consistent with each other. The crosslinking byproducts increase the charge mobility in LDPE. ©2010 IEEE.