Change in partial discharge properties of a void in LDPE

Partial Discharges (PD) cause the degradation of insulating materials and govern the lifetime of high-voltage power apparatus and cables. Therefore, it is important to understand the PD behaviors in the aging process. In this paper, partial discharges and their current shapes of low-density polyethylene (LDPE) with a void were measured. The PD φ-q-n pattern and the current shape changed remarkably with time and were related to each other. They depended not only upon the size and shape of voids but also on the degree of PD degradation. This suggests the possibility of insulation diagnosis using PD characteristics