High-field dielectric property and AC dissipation current waveform of polyethylene film

The authors have developed a novel method for the detection of AC dissipation current and its waveform for dielectric materials under high AC field. Using this technique, high-field dielectric properties and their relation to AC dissipation current waveforms of low-density polyethylene (LDPE) films were measured. Around room temperature, tan δ of a LDPE film has a small electric-field dependence. In this region, the dissipation current waveform shows saturation around the voltage peaks in phase even with high-field application. At higher temperatures, however, the high-field tan δ tends to have large field dependence. In this region, the AC dissipation current waveform deforms and exhibits nonlinear behavior around the voltage peaks