Frequency dependence of interfacial space charge formed in laminated dielectrics under AC voltage application conditions

The frequency dependence of interfacial space charge was experimentally obtained for LDPE/EVA laminated dielectrics in the frequency range of dc to 50 Hz. It was found that there are high, low and intermediate transition frequency regions in this performance. Interfacial space charge might be governed in principle by the Maxwell-Wagner type polarization, but modified by a semi-blocking contact of the interface in the low frequency region, and by a limited number of carriers in the high frequency region. Increased voltage induces carriers in the interface to become less mobile or more trapped. Both phenomena occur in the transition region.