Conduction currents in composite aromatic polyamide insulation

Typical conduction currents have been determined for a composite polyamide sample at a constant poling temperature of 2000°C and various poling fields ranging from 1.31 to 9.84 MVm^-1. The conduction current is observed to decay with time, and does not reach steady-state even after five hours from the time the electric field is applied. Isochronal currents are plotted as a function of applied electric field at various constant temperatures for 152.4 μm thick paper of composite polyamide. The electrode material is A1. Two distinct regions are observed, one at electric fields below 4 kVcm^-1 where conduction currents are Ohmic; and the other at electric fields greater than 4kVcm^-1, where the conduction currents deviate from Ohmic behaviors