Abstract: An electromagnetic device comprises a magnetic field generating electrical circuit including a winding (1) having at least one electrical conductor (2). The winding comprises a solid insulation (4) surrounded by outer and inner layers (3, 5) serving for equalization of potential and having semiconducting properties. Said at least one electrical conductor (2) is arranged interiorly of the inner semiconducting layer (3). The invention also relates to methods for electric field control and production of a magnetic circuit as well as use of a cable for obtaining a winding.

Abstract: A conductor for high-voltage windings comprising a stranded conductor core surrounded an electrical high-voltage insulation comprising an inner semi-conducting layer, an insulating layer and an outer semi-conducting layer. The core being designed to ensure uniform current distribution and to counteract eddy-current losses This is achieved by an electrically insulating oxide layer being provided on a sufficient number of strands to ensure that all strands in the stranded conductor core are electrically insulated from each other.

Abstract: The present invention relates to a rotating electric high voltage machine comprising a stator (8), a rotor (7; 37; 47) and at least one winding. The machine is characterized in that said winding comprises at least one current-carrying conductor (2), that a first layer (3) having semiconducting properties is provided around said conductor, that a solid insulating layer (4) provided around said first layer, and that a second layer (5) having semiconducting properties is provided around said insulating layer.

Abstract: A rotating electric machine with high-voltage stator winding and spring-device supporting the winding and method for manufacturing the same is employed for high-voltage applications. In particular, the machine includes a stator with a winding that is made of a high-voltage cable that is drawn through a slot in the stator of the rotating electric machine. A spring member biases the high-voltage cable against a wall of the stator so as to avoid damaging an outer surface of the cable during operation of the machine. The outer surface of the cable is susceptible to being damaged because an outer surface of the cable includes a semiconducting material that could possibly be damaged if subject to vibration or abrasion against a slot wall of the slot.

Abstract: A rotating electric machine (1) having a stator (2) provided with windings and a rotor (4) provided with windings and with salient poles (10) forming pole gaps (9) between the pole shoes (12) of the poles (10), which rotor (4) is arranged to be cooled by air flowing axially through the pole gaps (9) of the rotor (4), wherein each pole gap (9) between the pole shoes (12) is covered by at least one covering member (14) and that the air gap (15) is equipped with a sealing ring (16) to limit axial air flow.

Abstract: The present invention relates to installations for transformerless generation of HVDC and wherein the installation comprises rotating high-voltage single-winding/multiple-winding machines and converters. The single-winding/multiple-winding machine comprises a magnetic circuit with one or more magnetic cores and one or more windings, phase-shifted in space, which comprise a cable with one or more current-carrying conductors (2), each conductor comprising a number of strands, around each strand there being arranged an inner semiconducting layer (3), around which is arranged an insulating layer (4) of solid insulation, around which is arranged an outer semiconducting layer (5).

Abstract: The invention relates to an insulated conductor (30) for high-voltage windings in electric machines and to a method of adapting the same. The insulated conductor comprises a number of strands (12), a first semi-conductive layer (14) surrounding the strands (12), a first insulating layer (16) surrounding the first semi-conductive layer (14) and a second semi-conductive layer (18) surrounding the first insulating layer (16), which second semi-conductive layer (18) is earthed at at least two different points along the insulated conductor (30). The electric contact in the second semi-conductive layer (18) is broken (20) between each pair of earthed points At said breaks (20) in the second semi-conductive layer (18) a device (24, 26) is arranged to reduce amplification of the electric field strength at said breaks (20).

Abstract: An electric high voltage AC machine intended to be directly connected to a distribution or transmission network (16) comprises at least one winding. This winding comprises at least one current-carrying conductor, a first layer having semiconducting properties provided around said conductor, a solid insulating layer provided around said first layer, and a second layer having semiconducting properties provided around said insulating layer. In addition grounding means (18, 24, 26, 28) are provided to connect at least one point of said winding to ground.

Abstract: A rotating electric machine and method for manufacturing the same in which a high-voltage cable is wound in a stator so as to make a winding. A feature of the high-voltage cable is that the cable includes an inner semiconducting layer, a solid insulation material, and an outer semiconducting layer. A casting compound is supplied in a slot that holds the cable in the stator so as to avoid damaging an outer surface of the cable.

Abstract: In a plant comprising one or more electric machines constructed with insulated conductors and connected for heavy current via insulated conductors, the magnetic circuit in at least one of these electric machines is connected directly to a high supply voltage of 20-800 kV, preferably higher than 36 kV. The insulation of the electric machine is built up of a cable (6) placed in its winding and comprising one or more current-carrying conductors (31) with a number of strands (36) surrounded by outer and inner semiconducting layers (34, 32) and intermediate insulating layers (33). The conductors (31) may be group-wise connected in parallel and semiconducting layers are therefore not required around every conductor in the group.

Abstract: A rotating electric machine for direct connection to all types of high-voltage networks, in which the magnetic circuit adapted for high voltage comprises a rotor, stator and windings. The winding comprising a conductor surrounded by a solid insulation system. The invention also relates to a method for manufacturing the same.

Abstract: A conductor and a rotating electric high-voltage machine that includes the conductor has a cable configured for high-voltage operation. The cable may be included as a winding for the rotating electric high-voltage machine. The conductor includes a first strand that is clad with an electrically insulating layer, and a second strand that is uninsulated whereas the first strand and the second strand are arranged in two or more layers of strands. The two or more layers of strands are insulated from one another. Furthermore, the first and second layers of the two or more layers of strands are arranged around a central core where the central core is at least one of an air core and a core of another material. The second strand is positioned so as not to be electrically contacting any other uninsulated strand.

Abstract: A rotating electric machine (1) having a stator (2) provided with windings and a rotor (4) provided with field windings and with salient poles (10) forming pole gaps (9) between the pole shoes (12) of the poles (10), which rotor (4) is arranged to be cooled by air flowing axially through the pole gaps (9) of the rotor (4), wherein each pole gap (9) between the pole shoes (12) is covered by at least one covering member (14) and that the air gap (15) is equipped with a sealing ring (16) to limit axial air flow.

Abstract: A device for coiling and uncoiling elongated goods (K), such as wire, cable or the like, onto a drum (13) comprises a support (12) with driving means (25) for a spreader arm (10). The spreader arm (10) is rotatably mounted on the support (12) and supports a gripping arm (14) for coiling and uncoiling the elongated goods (K) onto the stationary drum (13). The gripping arm (14) is formed as a curved V-profile having a running track arranged for the elongated goods (K), which running track is oriented towards the drum (13). The said running track is defined by feeding rollers mounted within the gripping arm (14). The feeding rollers are spherical in shape and have a rolling resistance near zero to eliminate twisting of the elongated goods (K) during coiling and uncoiling.

Abstract: A method and apparatus for location of partial discharges in an electric high-voltage apparatus, such as a power transformer, which is arranged in a container filled with an insulating medium is provided. At least three ultrasonic detectors are applied with mutually known positions on the outside of the container and in acoustic contact therewith. The times of arrival of a wavefront arriving at the detectors and originating from a partial discharge are determined, and on the basis of the times of arrival and on the basis of the known mutual positions of the detectors, the direction the partial discharge is determined.

Abstract: The present invention relates to a rotating asynchronous converter and a generator device. The converter comprises a first stator connected to a first AC network with a first frequency f1, and a second stator connected to a second AC network with a second frequency f2. The converter also comprises a rotor means which rotates in dependence of the first and second frequencies f1, f2. The stators each comprises at least one winding, wherein each winding comprises at least one current-carrying conductor, and each winding comprises an insulation system, which comprises on the one hand at least two semiconducting layers, wherein each layer constitutes substantially an equipotential surface, and on the other hand between them is arranged a solid insulation.

Abstract: The present invention relates to a DC transformer/reactor comprising a magnetic circuit, wherein the magnetic circuit comprises a magnetic core and at least one winding. The winding comprises at least one current-carrying conductor. Each winding comprises also an insulation system, which comprises on the one hand at least two semiconducting layers, wherein each layer constitutes substantially an equipotential surface, and on the other hand between them is arranged a solid insulation.

Abstract: This invention is related to a device and a method in an electric power plant for protection of an object (1) against over-currents from a network (3) or another equipment included in the high voltage plant, the device comprising a switching device (4) in a line (2) between the object and the network/equipment. The line (2) between the object and the network/equipment is connected to an arrangement (5) reducing over-currents towards the object (1), said arrangement (5) being actuatable for over-current reduction with the assistance of an over-current condition detecting arrangement (11-13) within a time period substantially less than the break-time of the switching device (4).

Abstract: An arrangement with a conductor (15) intended to be on a high potential and a part (12) connected to ground and separated therefrom by at least a voltage receiving air gap (16, 17), comprising an insulating envelope (18) surrounding said conductor and at least a first member (9) of electrical insulating material arranged to screen off said ground part from said conductor. Said air gap is dimensioned to get such a high electrical field strength by possible sudden, strong voltage raises of said conductor, that air molecules in said air gap will be ionized. Said insulating envelope (18) and the insulating member (9) have surfaces arranged to receive electrical charges generated through said ionizing for creating a voltage over their thicknesses and decreasing the voltage drop in the air gap between the conductor (15) and the ground part (12).

Abstract: The line section of a gas-insulated line contains a high-voltage electric conductor and a pressure pipe which is made from a thermoplastic material and filled with insulating gas. The pressure pipe holds the electric conductor on insulated supports. The pressure pipe has two pipes which are welded to one another on the end faces thereof, the end section being respectively widened to flare outwardly in the radial direction with the welding of the two pipes.