Abstract: There is disclosed a transformer, comprising a triangular wound core; a low voltage LV winding; and at least one high voltage HV foil disc winding and a method for manufacturing a transformer coil, comprising providing a high voltage HV inner mold assembly; and winding at least one HV foil disc winding on the HV inner mold assembly. There is also disclosed a mold for manufacturing a transformer coil, comprising side gears respectively arranged at top and bottom positions of a triangular wound core; a high voltage HV inner mold assembly connected to the side gears; and a HV outer mold assembly connected to the side gears, wherein the HV outer mold assembly has a top opening across a length thereof.

Abstract: Exemplary embodiments are directed to a heat exchanger system for transformers or reactors having at least one coil being cooled by gaseous fluids circulating around the transformer. The system having an enclosure that houses the transformer and the at least one coil, where flow of cooling gaseous fluid passes over the coil and is heated by the heat of the transformer or reactor the heated gas is directed to pass over a thermosiphon heat exchanger which dissipates the heat to a cooling media.

Abstract: A transformer core is disclosed, which can include at least three hollow-cylindrical rectangular shaped core-discs wound from a magnetic band-like material, wherein two opposed limb areas and an upper and lower yoke area can be formed along a circumferential path. The core-discs can include one first and at least one second slanted area parallel to the circumferential path in the belonging limb area. The at least three core-discs can be connected according to a polygonal layout at their first slanted areas, which can be arranged adjacently face to face. Conical shaped polygonal adapter plates fitted to the polygonal layout within the upper and lower yoke areas, which can be clamped together.

Abstract: Mold-free resin-insulated coil windings are obtained by applying continuous fibers embedded in a quasi-solid-state epoxy-resin matrix, e.g. in the form of a tape, to the coil windings. The tape is locally heated up to the melting point of its polymer matrix, and is subsequently pressed against the winding body. The heated and fused resin of the tape, which is pressed onto the coil, flows under pressure into the voids and gaps between the coil windings and fills them up, thereby hermetically insulating the coil windings. After leaving the heating and pressing apparatus the fused epoxy resin becomes solid again. The resulting curing process is thus considerably simplified and shortened, compared to the state of the art.

Abstract: A curable epoxy resin composition including at least an epoxy resin component and a hardener component, and optionally further additives, wherein: (a) the epoxy resin component is an epoxy resin compound or a mixture of such compounds; (b) the hardener component includes (b1) an aliphatic and cycloaliphatic or aromatic polycarbonic acid anhydride; and (b2) a polyether-amine of the general formula (I), H2N—(CnH2n—O)m—CnH2n—NH2, wherein n is an integer from 2 to 8; and m is from about 3 to about 100; (c) the polycarbonic acid anhydride [component (b1)] is present in the curable epoxy resin composition in a concentration of 0.60 Mol to 0.93 Mol; and (d) the polyether-amine of the general formula (I) [component (b2)] is present in the curable epoxy resin composition in a concentration of about 0.02 Mol to about 0.1 Mol.

Abstract: Exemplary embodiments are directed to a heat exchanger system for transformers or reactors having at least one coil being cooled by gaseous fluids circulating around the transformer. The system having an enclosure that houses the transformer and the at least one coil, where flow of cooling gaseous fluid passes over the coil and is heated by the heat of the transformer or reactor the heated gas is directed to pass over a thermosiphon heat exchanger which dissipates the heat to a cooling media.

Abstract: An exemplary curable epoxy resin composition is disclosed which includes at least an epoxy resin component and a hardener component, and optionally further additives, wherein (a) at least a part of the hardener component is a chemically modified polycarbonic acid anhydride; (b) an optional glycol or polyglycol; (c) or a compound containing two carboxylic groups is included; and (d) the chemically modified acid anhydride hardener is present in an amount comprising at least 10% of reactive hardening groups calculated to all the reactive hardening groups contained in the total amount of hardener component present in the epoxy resin composition.

Abstract: A curable epoxy resin composition including at least an epoxy resin component and a hardener component, and optionally further additives, wherein: (a) the epoxy resin component is an epoxy resin compound or a mixture of such compounds; (b) the hardener component includes (b1) an aliphatic and cycloaliphatic or aromatic polycarbonic acid anhydride; and (b2) a polyether-amine of the general formula (I), H2N—(CnH2n—O)m—CnH2n—NH2, wherein n is an integer from 2 to 8; and m is from about 3 to about 100; (c) the polycarbonic acid anhydride [component (b1)] is present in the curable epoxy resin composition in a concentration of 0.60 Mol to 0.93 Mol; and (d) the polyether-amine of the general formula (I) [component (b2)] is present in the curable epoxy resin composition in a concentration of about 0.02 Mol to about 0.1 Mol.

Abstract: Curable epoxy resin composition, which is suitable for the production of electrical insulation systems for low, medium and high voltage applications, including at least an epoxy resin, a hardener, a mineral filler material, and optionally further additives, wherein (i) the epoxy resin component is a diglycidylether of bisphenol A (DGEBA); (ii) the hardener includes methyltetrahydrophthalic anhydride (MTHPA) and polypropylene glycol (PPG), wherein (iii) the average molecular weight of the polypropylene glycol (PPG) is within the range of about 300 to about 510 Dalton; and (iv) the molar ratio of methyltetrahydrophthalic anhydride (MTHPA) to polypropylene glycol (PPG) is within the range of about 9:1 to 19:1. A method of making the epoxy resin composition and electrical articles made therefrom are also provided.

Abstract: A surface modified electrical insulation system having a super hydrophobic surface, the insulation system having a hardened or cured synthetic polymer composition which contains at least one filler material and optionally further additives. The at least one filler material can be selected from a group of filler materials containing inorganic oxides, inorganic hydroxides and inorganic oxyhydroxides. The surface of the electrical insulation system can be formed as a structured surface with micro-scale and nano-scale features, whereby the surface is covered with a liquid hydrophobic compound.

Abstract: A curable epoxy resin composition is provided. The composition includes at least one diglycidyl ether of bisphenol A (DGEBA) and at least one diglycidyl ether of bisphenol F (DGEBF) as epoxy resins, in which the weight ratio of DGEBA:DGEBF is within the range of about 15:85 to 45:55; (ii) an anhydride hardener; (iii) and at least one plasticizer. The composition can additionally include a catalyst, at least one filler material and/or further additives. The dynamic complex viscosity value (?*) of the composition is within the range of 0.1 to 20 Pa·s. The present disclosure also provides a process for making the composition and electrical articles including an electrical insulation system made from the composition.

Abstract: To improve its fire resistance, the winding of a low voltage coil for a dry transformer is, at its circumferential surface, covered by a wrap made up of four turns of a protective foil comprising a layer consisting of woven glass fibers impregnated with silicone resin with an admixture of mica. An inner part winding and an outer part winding are separated by a gap comprising twelve rectangular aluminium tubes as spacers. At a lower end, the end face of the winding is covered with a protective cover comprising epoxy resin.

Abstract: A hardenable epoxy resin composition which is suitable for the production of an electrical insulation with improved thermal ageing properties, wherein said hardenable epoxy resin composition comprises an epoxy resin, a hardener, an inorganic filler composition, and a coupling agent for improving the bonding between the polymer matrix and the filler, and optionally further additives. The filler composition comprises silica and aluminum trihydride (ATH). The composition can be used for the production of an electrical insulation, and electrical articles containing such an electrical insulation system.

Abstract: Mold-free resin-insulated coil windings are obtained by applying continuous fibers embedded in a quasi-solid-state epoxy-resin matrix, e.g. in the form of a tape, to the coil windings. The tape is locally heated up to the melting point of its polymer matrix, and is subsequently pressed against the winding body. The heated and fused resin of the tape, which is pressed onto the coil, flows under pressure into the voids and gaps between the coil windings and fills them up, thereby hermetically insulating the coil windings. After leaving the heating and pressing apparatus the fused epoxy resin becomes solid again. The resulting curing process is thus considerably simplified and shortened, compared to the state of the art.

Abstract: A dry-type transformer is disclosed wherein the transformer coils are encapsulated with a cured mineral filler containing cyanate ester resin composition which optionally is a cured mineral filler containing epoxy modified cyanate ester resin composition. A method of making the insulating composition, and the non-cured composition, are also disclosed.

Abstract: An elastomeric composition includes at least one diene elastomeric polymer; at least one reinforcing filler; from 0.05 phr to 10 phr of zinc oxide; from 0.1 phr to 20 phr of at least one fatty acid amide; and from 0.1 phr to 15 phr of at least one zinc salt of a carboxylic acid of formula R—COOH. R is selected from linear or branched C1-C24 alkyl groups, linear or branched C2-C24 alkenyl groups, C5-C24 cycloalkyl groups, C6-C24 aryl groups, C7-C24 alkylaryl or arylalkyl groups. A tyre for a vehicle wheel includes a carcass structure, belt structure, tread band, and pair of sidewalls. At least one tyre structural element includes a crosslinked elastomeric material obtained by crosslinking the elastomeric composition. The at least one structural element including the crosslinked elastomeric material may be the tread band. A related tyre tread band and crosslinked elastomeric manufactured product are also disclosed.

Abstract: The disclosure relates to a process for improving the processability, storage stability and/or cure rate of an uncured silica reinforced rubber composition where silica comprises the major filler in the reinforced rubber composition, which comprises combining a mixture comprising, rubber, silica and at least one organic compound having a low molecular weight and a functional group wherein said functional group is at least an epoxy group, such as an epoxy/ether, epoxy/hydroxyl, epoxy/ester, epoxy/amine, ether/amine, episulfide, episulfide/ether, episulfide/hydroxyl, episulfide/ester functional group located in a terminal or sterically unhindered position in the molecule of said organic compound where the molecular weight of said organic compound having a low molecular weight is less than 7,000, or the organic compound comprises an abietyl, styrenated resorcinol formaldehyde, or ester hydroxyl organic compound having a hydroxyl, ester, and optionally, an ether group, such as an ester diol.

Abstract: The disclosure relates to a process for improving the processability, storage stability and/or cure rate of an uncured silica reinforced rubber composition where silica comprises the major filler in the reinforced rubber composition, which comprises combining a mixture comprising, rubber, silica and at least one organic compound having a low molecular weight and a functional group wherein said functional group is at least an epoxy group, such as an epoxy/ether, epoxy/hydroxyl, epoxy/ester, epoxy/amine, ether/amine, episulfide, episulfide/ether, episulfide/hydroxyl, episulfide/ester functional group located in a terminal or sterically unhindered position in the molecule of said organic compound where the molecular weight of said organic compound having a low molecular weight is less than 7,000, or the organic compound comprises an abietyl, styrenated resorcinol formaldehyde, or ester hydroxyl organic compound having a hydroxyl, ester, and optionally, an ether group, such as an ester diol.

Abstract: The disclosure relates to a process for improving the processability, storage stability and/or cure rate of an uncured silica reinforced rubber composition where silica comprises the major filler in the reinforced rubber composition, which comprises combining a mixture comprising, rubber, silica and at least one organic compound having a low molecular weight and a functional group wherein said functional group is at least an epoxy group, such as an epoxy/ether, epoxy/hydroxyl, epoxy/ester, epoxy/amine, ether/amine, episulfide, episulfide/ether, episulfide/ hydroxyl, episulfide/ester functional group located in a terminal or sterically unhindered position in ii the molecule of said organic compound where the molecular weight of said organic compound having a low molecular weight is less than 7,000, or the organic compound comprises an abietyl, styrenated resorcinol formaldehyde, or ester hydroxyl organic compound having a hydroxyl, ester, and optionally, an ether group, such as an ester diol.

Abstract: The disclosure relates to a process for improving the processability, storage stability and/or cure rate of an uncured silica reinforced rubber composition where silica comprises the major filler in the reinforced rubber composition, which comprises combining a mixture comprising, rubber, silica and at least one organic compound having a low molecular weight and a functional group wherein said functional group is at least an epoxy group, such as an epoxy/ether, epoxy/hydroxyl, epoxy/ester, epoxy/amine, ether/amine, episulfide, episulfide/ether, episulfide/hydroxyl, episulfide/ester functional group located in a terminal or sterically unhindered position in the molecule of said organic compound where the molecular weight of said organic compound having a low molecular weight is less than 7,000, or the organic compound comprises an abietyl, styrenated resorcinol formaldehyde, or ester hydroxyl organic compound having a hydroxyl, ester, and optionally, an ether group, such as an ester diol.