Development of oil-impregnated, all-polypropylene film power capacitor

A newly developed all-polypropylene-film power capacitor is described here. The size of the capacitor is about half that of the conventional types and its dielectric loss is less than one-seventh. We succeeded in this development by studying insulating fluids, films and several factors in the production of capacitors to yield good electrical insulation which is free from voids that occur due to swelling of the film and to imperfect impregnation of the all-film construction.