Discharges in all-PP film model capacitors

Discharges in model capacitors made of polypropylene impregnated with an organic liquid are studied with a digital analyzer. The effect of the nature of the liquid (aliphatic or aromatic hydrocarbon) and the influence of parameters such as voltage, pressure and temperature on the main characteristics of the discharges are investigated. Discharges were monitored during aging tests of the models. It is concluded that aging of the models tested at high electric fields ( approximately 135 V/ mu m) is not due to discharges but to the chemical degradation of polypropylene due electrical and thermal stresses.<
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