PD characteristics according to applied voltages and void aspects in LDPE

Flat type voids are made in low density polyethylene, which are different in size and number of voids, for the purpose of investigation of PD characteristics according to applied voltage and void aspects. The PD quantities measured are discharge current and energy, peak PD magnitude and repetition rate. As the experimental results, the discharge mode is changed Townsend to streamer depending on the increasement of applied voltage. The generation of large peak charge may be affected by tangential electrical stress due to charged neighbor sites. This effect is verified by simulation. Increases of repetition rate may be explained by the fact that the discharges generated in each discharging site are amassed.