The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially for an electrical machine, e.g., a high-voltage machine, such as a generator for generation of electrical energy, an electric motor, or another piece of electrical equipment having a relatively high rated voltage, e.g., a transformer or a bushing or a cable. A corona shielding system may include: a polymeric matrix; and filler particles comprising mica surrounded by a layer of at least one ceramic metal oxide. The filler particles may be distributed throughout the polymeric matrix.

The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially for an electrical machine, e.g., a high-voltage machine, such as a generator for generation of electrical energy, an electric motor, or another piece of electrical equipment having a relatively high rated voltage, e.g., a transformer or a bushing or a cable. A corona shielding system may include: a polymeric matrix; and filler particles comprising mica surrounded by a layer of at least one ceramic metal oxide. The filler particles may be distributed throughout the polymeric matrix.

The present technology provides an electrical insulating material comprising a plurality of insulating dielectric layers and a thermally conductive layer disposed between adjacent dielectric layers, the thermally conductive layer comprising a thermally conductive filler. Additionally, the present technology also provides a method of manufacturing the electrical insulating material. The present technology also provides an electrically conductive apparatus comprising an electrically conductive material and an electrical insulating material disposed about the conductive material, the electrical insulating material comprising a first dielectric layer, a second dielectric layer overlying the first dielectric layer, and a thermally conductive layer disposed between the first and second dielectric layers, the thermally conductive layer comprising a thermally conductive filler, e.g., born nitride.

A paper suitable for use in a battery or battery pack as a flame barrier or thermal insulation, the paper comprising 60 to 95 weight percent aerogel powder and 5 to 40 weight aramid polymer fibrils; the paper having a thickness of 50 to 4000 micrometers.

A cable contains a core including a transmissive element and a coating layer made of a coating material. The coating material contains, with respect to the total weight of polymeric materials present in the composition, (i) 70% to 95% by weight of a recycled linear low density polyethylene (r-LLDPE); and (ii) 5 to 30% by weight of an ethylene-vinyl acetate copolymer (EVA). The EVA may be added to the r-LLDPE or, alternatively, be already contained in the r-LLDPE as a result of previous LLDPE use. The cable may further contain a skin layer placed around and in direct contact with the coating layer based on r-LLDPE.

A fire-resistive cable system comprises an electrical cable housed in a fiberglass-reinforced thermosetting resin conduit. The electrical cable comprises a conductor and has only one couple of mica tapes surrounding the conductor. The couple of mica tapes are formed of a first mica tape and a second mica tape wound around the first mica tape. The mica layer of the first mica tape faces and contacts the mica layer of the second mica tape. The fiberglass-reinforced thermosetting resin conduit is made of a material comprising fibers of a glass selected from E-glass and E-CR-glass, and a resin.

A fire-resistive cable system comprises an electrical cable housed in a fiberglass-reinforced thermosetting resin conduit. The electrical cable comprises a conductor and has only one couple of mica tapes surrounding the conductor. The couple of mica tapes are formed of a first mica tape and a second mica tape wound around the first mica tape. The mica layer of the first mica tape faces and contacts the mica layer of the second mica tape. The fiberglass-reinforced thermosetting resin conduit is made of a material comprising fibers of a glass selected from E-glass and E-CR-glass, and a resin.

A flame resistant electrical insulating material comprises glass fibers, a particulate filler mixture, and an inorganic binder, wherein the electrical insulating material has a UL-94 flammability rating of V-0, 5VA and a thermal conductivity of less than 0.15 W/m-K. The particulate filler mixture comprises at least two particulate filler materials selected from the list of glass bubbles, kaolin clay, talc, mica, calcium carbonate, and alumina trihydrate. In an exemplary aspect, the insulating material is not punctured after direct exposure to 2054° C. (3730° F.) flame for at least 10 minutes.

A flame resistant electrical insulating material comprises glass fibers, a particulate filler mixture, and an inorganic binder, wherein the electrical insulating material has a UL-94 flammability rating of V-0, 5VA and a thermal conductivity of less than 0.15 W/m-K. The particulate filler mixture comprises at least two particulate filler materials selected from the list of glass bubbles, kaolin clay, talc, mica, calcium carbonate, and alumina trihydrate. In an exemplary aspect, the insulating material is not punctured after direct exposure to 2054° C. (3730° F.) flame for at least 10 minutes.

Resin-rich mica tapes comprising one or more than one layer of mica paper and one or more than one layer of a nonmetallic inorganic fabric, in particular a glass fabric, which are pre-impregnated with an impregnation resin composition comprising an epoxy resin with more than one epoxy group, which is solid or semisolid at ambient temperature, a latent curing agent for said epoxy resin, about 5 to about 20% by weight of hexagonal boron nitride of a particle size (D50) of equal or less than about 3 μm, about 0.05 to about 1% by weight of a wetting agent and a suitable solvent which is removed after pre-impregnation of the mica tape with the impregnation resin mixture are useful to prepare electrical insulations with excellent thermal conductivity and dielectric dissipation factor.