DC and AC breakdown voltage behavior of high voltage multi-layer encapsulated coils

The trend in designing small and lightweight miniaturized high voltage electric and electronic equipments has increased over the last two decades. This was generally achieved by using solid potting and multi-layer insulation systems with reduced size of insulation layers and by using fine gauge magnet wires. Further, PET thermoplastic encapsulation of coils and electronic devices has also been used for electrical insulation, heat dissipation and physical protection of the encapsulated devices from harsh environmental operating conditions. This paper presents the results of breakdown tests on units of high voltage multi-layer encapsulated coils at DC and AC voltages. The effect of the temperature and moisture absorption on the breakdown is also investigated. The breakdown were presented by Weibull statistical distribution