Abstract: A coil insulator of an electrical rotating machine used as a main insulator for insulating a bundle of conductors formed of a plurality of insulated wires to form an armature coil provided in a slot of a rotor core or a stator core of an electrical rotating machine, wherein the coil insulator includes a mica layer including at least one of a peeled-off mica and a composite mica, a woven- or unwoven cloth including at least one of inorganic and organic materials, hexagonal crystal boron nitride particles having a graphitization index of 1.8 or more, and thermosetting polymer organic resin which integrally connects the mica layer and the hexagonal crystal boron nitride particles to each other, and the hexagonal crystal boron nitride particles is oriented in a longitudinal direction of the coil.

Abstract: According to the present invention, a method of detecting water leakage in a coil, which determines whether or not cooling water leaks into an insulation layer, the water being supplied to a conductor of a coil covered with the insulation layer, including: applying an AC voltage to the conductor; bringing a surface electrode device into pressure contact with the insulation layer; grounding the surface electrode device through an impedance; measuring a potential of the surface electrode device; and determining that the cooling water leaks from the conductor into the insulation layer when a measured potential is higher than a potential of a normal coil

Abstract: A coil for an electric rotating machine is configured with a conductor which is formed by bundling a plurality of square strands and stacking the square strands like a coil with Roebel transposition, mica tape which is wound a plurality of layers around an outer surface of the conductor and made up of mica paper and glass cloth backing, and an insulation wall formed by impregnating and curing resin between wound layers of the mica tape. Inorganic particles are supported with the glass cloth backing on the mica tape using an adhesive containing glue insoluble in the impregnated resin as an indispensable component.

Abstract: A coil insulator of an electrical rotating machine used as a main insulator for insulating a bundle of conductors formed of a plurality of insulated wires to form an armature coil provided in a slot of a rotor core or a stator core of an electrical rotating machine, wherein the coil insulator includes a mica layer including at least one of a peeled-off mica and a composite mica, a woven- or unwoven cloth including at least one of inorganic and organic materials, hexagonal crystal boron nitride particles having a graphitization index of 1.8 or more, and thermosetting polymer organic resin which integrally connects the mica layer and the hexagonal crystal boron nitride particles to each other, and the hexagonal crystal boron nitride particles is oriented in a longitudinal direction of the coil.

Abstract: A coil for an electric rotating machine is configured with a conductor which is formed by bundling a plurality of square strands and stacking the square strands like a coil with Roebel transposition, mica cape which is wound a plurality of layers around an outer surface of the conductor and made up of mica paper and glass cloth backing, and an insulation wall formed by impregnating and curing resin between wound layers of the mica tape. Inorganic particles are supported with the glass cloth backing on the mica tape using an adhesive containing glue insoluble in the impregnated resin as an indispensable component.

Abstract: A coil for an electric rotating machine is configured with a conductor which is formed by bundling a plurality of square strands and stacking the square strands like a coil with Roebel transposition, mica tape which is wound a plurality of layers around an outer surface of the conductor and made up of mica paper and glass cloth backing, and an insulation wall formed by impregnating and curing resin between wound layers of the mica tape. Inorganic particles are supported with the glass cloth backing on the mica tape using an adhesive containing glue insoluble in the impregnated resin as an indispensable component.

Abstract: A partial discharge detection apparatus of an electrical rotating machine includes a metal frame connected to a stator frame of the electrical rotating machine, a power line connected to one of a stator winding corresponding to one phase of three phases in the metal frame and a neutral point lead line connected to a neutral point of three-phase stator windings and arranged in the metal frame to propagate a partial discharge signal generated by degradation of the stator winding, a sensor including a rod antenna which is installed around the power line or neutral point lead line in the metal frame to electrostatically and magnetically induce the partial discharge signal propagated to the power line or neutral point lead line, and a detector which receives, via a signal lead line, a signal generated in the sensor and detects partial discharge by signal processing.

Abstract: A coil for an electric rotating machine is configured with a conductor which is formed by bundling a plurality of square strands and stacking the square strands like a coil with Roebel transposition, mica cape which is wound a plurality of layers around an outer surface of the conductor and made up of mica paper and glass cloth backing, and an insulation wall formed by impregnating and curing resin between wound layers of the mica tape. Inorganic particles are supported with the glass cloth backing on the mica tape using an adhesive containing glue insoluble in the impregnated resin as an indispensable component.

Abstract: A remaining life of a stator coil resulting from galvanic corrosion between different kinds of metals in a rotating machine adopting a water cooling system and remaining life of a stator coil's insulating layer resulting from a wet heat degeneration can be positively and integrally evaluated according to the present invention by sampling a brazing section between the stator coil clip and copper wires, cutting off the sampled brazing section in a copper wire array direction, measuring a joined section brazed with a brazing material as a copper wire direction length and finding an effective sealing length of that brazing section or sampling an insulating layer of the stator coil, finding infrared spectra of the insulating layer, comparing the infrared spectra of the insulating layer of the stator coil with infrared spectra of a healthy stator coil's insulating layer not penetrated by water, finding difference spectra of an ester group of an epoxy resin used as a bonding agent of the insulating layer and predict