Charge behavior in LDPE at polarity reversal and various DC voltages

The space charge distribution in multi-ply polymeric dielectrics at different DC voltage loads and with polarity reversal is analyzed. The space charge distributions at the metal-polymer interface and polymer-polymer interface were observed by a pulsed electroacoustic method. The electric field distribution was also calculated according to the space charge distribution. Low-density polyethylene (LDPE) was chosen as the sample in the experiment. It is shown that, under an applied DC voltage, a heterocharge distribution can be observed in LDPE not only at the metal-polymer interface but also at the polymer-polymer interface between the two pieces of the samples. The electric field modification was calculated from the space charge distribution. Whether at the metal-polymer interface or at the polymer-polymer interface, the electric field was stronger than that in the bulk because the space charge tends to accumulate at the vicinities of the interfaces