Transient response of various kinds of high field alternating signals for low density polyethylene

Polyethylene is widely used as the insulator for power cable. By using dissipation current waveform observation system, which is developed by authors, frequency dependences of dissipation current waveform for LDPE film has been investigated and reported so far. In previous paper, it was described that the instantaneous changing rate of the electric field is the one of important factor to study the charge injection and space charge formation under AC high field. In order to investigate the effect of the changing rate of electric field, the transient responses under various kinds of high field trapezoid like waveform are applied to the 70 μm thick LDPE film samples. As the results of these experiments, it will discuss the high field AC conduction mechanism with the charge injection and space charge formation.