Abstract: A power capacitor including at least one capacitive winding, of self-healing type, located in a case made of plastic material and coated in a polymerizable resin cast directly into the case. The capacitor includes a breaking device sensitive to an overpressure. Passage of gases in the direction of the breaking device is achieved by deformation of the plastic material constituting the case. The plastic material of the case presents predetermined mechanical strength, impact strength and thermal resistance characteristics.

Abstract: The manufacturing process of a capacitor with a polypropylene dielectric film by introducing pre-cross-linking elements of the polypropylene at the time of manufacturing. When the capacitor is used, the electrical field and/or temperature generated trigger the cross-linking process of the polypropylene, delaying and slowing down the ageing phenomena, i.e. the decrease of the dielectric strength. The pre-cross-linking agent is a polyfunctional monomer to which an activation accelerator and/or a stabilizing agent can be added.

Abstract: Low voltage power capacitor of the self-healing type, wherein each capacitor cell is fitted with individual protection, enabling the cell to be disconnected in all cases of faults which are liable to occur. The cell coil is electrically connected in series to a fuse housed in a chamber arranged in the sealing cover of the casing housing the coil. Protection against overpressures inside the casing is provided by a membrane, deformation of which actuates a short-circuiting contact. The clean short-circuit, generated by closing of the short-circuiting contact, causes the fuse to blow and the faulty cell to be disconnected.