Metallized film capacitors withstand the superimposed AC and DC voltage waveform when used as DC support capacitors

which affects the breakdown and self-healing characteristics of the capacitors

further directly impairs their reliability. This paper takes a 4μm-thick metallized polypropylene films as the research objects and constructs a breakdown and self-healing platform for metallized films under complex voltage waveforms. By controlling the ratio k of AC to DC components in the complex voltage

the influence of the complex voltage waveform on the breakdown and self-healing characteristics of the metallized film is studied. Research has shown that the breakdown characteristics of metalized films are significantly affected by the composite voltage waveform

manifested as a more concentrated distribution of breakdown phase angle with an increase in the proportion of AC/DC components k

and the breakdown concentration occurs at the peak of the AC voltage component. In addition

the breakdown voltage decreases as the proportion of the AC/DC components k in the composite voltage waveform increases. The AC-DC voltage waveforms mainly change the self-healing characteristic by affecting the breakdown characteristic. At the same breakdown voltages

self-healing characteristic parameters such as self-healing energy and self-healing area are not affected by the ratio of AC/DC components k.