Characteristics of partial discharge in various polyethylenes

Partial discharge (PD) signals in various polyethylenes such as low density polyethylene (LDPE), crosslinked polyethylenes (XLPE) and chemically modified polyethylenes are measured by an ultrasonic signal detection systems, and their characteristics are analyzed. The PD characteristics of commercial XLPEs are different from sample to sample. PD activities in XLPE are more extensive than those in LDPE, which depends on the type of polyethylene. PD activities are suppressed in the tree-retardant XLPEs as compared to the conventional XLPEs. A chemical modification of LDPE using an acrylic acid suppresses PD activities in LDPE. Details of these results are described.