Partial discharges as a recognition tool of defects in all-film capacitor models

Artificial defects simulating manufacture vices have been intentionally introduced in an all-film capacitor model (for example, poor impregnation, floating contact). The partial discharges (pd) induced therein under AC stress were recorded and studied as a function of time and voltage. The partial discharge inception voltage, the evolution with time of both discharge frequency and apparent charge and the shape of phase distributions of the apparent charge and discharge number are the main parameters which relate each pd recording to its cause.