Harmonic content in the partial discharge current measured with dielectric spectroscopy

Phase resolved partial discharge analysis and dielectric spectroscopy measurements have been performed at 50 Hz and variable voltage on two artificial defects that have different average charge phase distributions. Influence of partial discharges on permittivity and loss-factor is deduced to the phase position of the partial discharge activity. Symmetry properties between positive and negative charge distributions have been related to the harmonic content of the partial discharge current.