Abstract: The magnetic circuit of a generator in a hydro-generator plant is arranged to directly supply a high supply voltage of 20-800 kV, preferably higher than 36 kV. The generator is provided with solid insulation and its winding includes a cable (6) comprising one or more current-carrying conductors (31) with a number of strands (36) surrounded by at least one outer and one inner semiconducting layer (34, 32) and intermediate insulating layers (33). The outer semiconducting layer (34) is at earth potential. The stator winding may be produced with full or fractional slot winding, the phases of the winding being Y-connected. The Y-point may be insulated and protected from over-voltage by means of surge arresters, or else the Y-point may be earthed via a suppression filter. The invention also relates to a hydro-generator plant, a generator included in the plant and a procedure for building such a plant.

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 synchronous machine for power and/or voltage control comprises a stator with a stator winding and a rotor with a field winding. The stator winding comprises a high-voltage cable with solid insulation. A rotor has a thermally based rotor current limit intersecting with a thermally based stator current limit in a capability graph at a power factor considerably below the rated power factor or has the thermally based rotor current limit above the thermally based stator current limit. In the capability graph. Means are provided for limiting the currents in order to avoid thermal damage. In a method for power and/or voltage control of such a synchronous machine, the machine operates with the stator current exceeding the thermally based stator current limit for a certain time period less than the maxim an permissible time limit, whereafter the overload is reduced by reduction of either the active power or the field current or a combination of both.

Abstract: A device that includes a combustion engine with a piston that is mechanically freely movable in a housing. The device permits combustion of a fuel mixture to produce a pushing force to the piston. The device includes an electromagnetic energy transducer and an external current circuit, which is connected to the energy transducer for exchange of effect in a direction to or from the energy transducer. A control unit controls the direction of the effect, which is exchanged between the energy transducer and the external current circuit, during operation of the device. Such a device can be used to generate electrical energy, and can be employed in a vehicle.

Abstract: An electrical machine with at least a machine unit. This machine unit includes a stator, which includes a plurality of magnetic flux conductors, an electric conductor forming a winding extending in a substantially closed winding path through each magnetic flux conductor, and a least one first movable element, which includes a number of permanent magnet elements and which is movable in a reciprocating movement in relation to the stator along a first movement path in a space having a finite length and formed by at least some of the magnetic flux conductors. The winding path includes a first current carrying portion, which extends substantially in parallel with the first movement path. Each magnetic flux conductor is arranged to form, together with one of the permanent magnetic elements, a closed magnetic flux circuit extending around the current carrying portion.

Abstract: An electrical machine with at least a machine unit. The machine unit includes a stator, which includes a plurality of magnetic flux conductors and an electric conductor forming a winding extending in a substantially closed winding path through each magnetic flux conductor, and a movable element, which includes permanent magnet elements movable in a reciprocating movement in relation to the stator along a movement path. The winding path includes a first current carrying portion, which extends substantially in parallel with the movement path. Each magnetic flux conductor is arranged to form, together with one of the permanent magnet elements, a closed magnetic flux circuit extending around the current carrying portion. The magnetic flux conductors are arranged in an alternating order with respect to the direction of the magnetic flux in relation to the permanent magnet elements in the respective magnetic flux circuit.

Abstract: A high power static electromagnetic device with variable inductance has a magnetic circuit with a flux bearing region. A main winding and at least one control winding surrounds the portions of the flux bearing region. A control device is coupled to the control winding for varying the distribution of flux. The winding is formed of a magnetically permeable, field-confining insulating cable.

Abstract: A distributed power generation system (100) has at least two distributed power sources (104) connected to a point of connection (150) to a power utility network by interconnections, and is provided with a system protection scheme. The system protection scheme comprises at least three system protection terminals (18). One system protection terminal (18A) is located in the vicinity of the point of connection (150), while two others (18B-E) are located in the vicinity of one power source (104) each. The system protection terminals (18) are interconnected by a communication system (22), using a substantially dedicated communication resource. The system protection terminals (18) are equipped to measure characteristics of the power system at that particular location, preferably complex ac quantities and stability indicators. The measurements are spread to other system protection terminals (18).

Abstract: Connection arrangements are employed for reducing the effect of third-hannonic voltages in case of direct connection of AC machines to a three-phase distribution or transmission network, wherein the stator winding of the AC machine is Y-connected and wherein the neutral point of the winding is available. An exemplary embodiment employs a suppression filter turned to the third-harmonic, with an overvoltage protection device arranged between the neutral point and ground of the power network.

Abstract: The invention refers to an electrical machine with at least a machine unit (1). The machine unit includes a stator, which includes a plurality of magnetic flux conductors (3′, 3″) and an electric conductor forming a winding extending in a substantially closed winding path through each magnetic flux conductor, and a movable element (10), which includes a number of permanent magnet elements (12′, 12″) and which is movable in a reciprocating movement in relation to the stator along a movement path. The winding path includes a first current carrying portion (6a), which extends substantially in parallel with the movement path. Each magnetic flux conductor (3′, 3″) is arranged to form, together with one of said permanent magnet elements (12′, 12″), a closed magnetic flux circuit extending around said current carrying portion.

Abstract: The invention refers to an electrical machine with at least a machine unit (1). This machine unit includes a stator, which includes a plurality of magnetic flux conductors (3′, 3″) and an electric conductor forming a winding extending in a substantially closed winding path through each magnetic flux conductor, and at least one first movable element (10), which includes a number of permanent magnet elements (12′, 12″) and which is movable in a reciprocating movement in relation to the stator along a first movement path in a space having a finite length and formed by at least some of said magnetic flux conductors. The winding path includes a first current carrying portion (6a), which extends substantially in parallel with the first movement path. Each magnetic flux conductor (3′, 3″) is arranged to form, together with one of said permanent magnet elements (12′, 12″), a closed magnetic flux circuit extending around said current carrying portion.

Abstract: The invention refers to a device, which includes a combustion engine (1) with a piston (2), which is mechanically freely movable in a housing (3). The device is arranged to permit combustion of a fuel mixture in order to produce a pushing force to the piston (2). The device includes an electromagnetic energy transducer (21, 22) and an external current circuit (34, 41), which is connected to the energy transducer for exchange of effect in a direction to or from the energy transducer. A control unit (12) is arranged to control the direction of the effect, which is exchanged between the energy transducer (21, 22) and the external current circuit, during operation of the device. The invention also refers to a use of such a device for generating electric energy, and a vehicle with such a device.

Abstract: A device for mechanically securing and controlling the potential of winding cables (10) outer semiconducting layers (14) in the end windings region of the stator (2) of a rotating high-voltage electric machine comprises spacers (12) of resilient, electrically conducting material arranged between the semi-conducting outer layers (14) of adjacent winding cables (10, 10′, 10″) Positioning devices (16, 18) are arranged to secure the cables in relation to each other with the outer layers in contact with the spacers.

Abstract: A method and device for providing series compensation for rotating electric alternating current machines connected either directly, or via a static current converter, to a three-phase distribution or transmission network. The stator of the electric machine is Y-connected. A capacitive circuit for the fundamental frequency of the voltage is connected to each phase between the low voltage side of the winding and a ground of the transmission network.

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: 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: Connection arrangements for reducing the effect of third-harmonic voltages in case of direct connection of AC machines (1) to a three-phase distribution or transmission network (5), wherein the stator winding of the AC machine is Y-connected and wherein the neutral point of the winding (2) is available, comprising a suppression filter (14) tuned to the third harmonic, with an overvoltage protection device (17) arranged between the neutral point (2) and ground of the power network (4).

Abstract: A rotor for short-circuited alternating current motors, having a pack of circular rotor blades fixedly mounted on a shaft, the plates have, uniformly around the peripheral edges thereof, a number of recesses which, when the plates are packed, form generally axially extending rotor slots, and each rotor slot includes a first recess or cavity whose peripheral edge forms a closed contour and which accommodates a conductor radially inwards of the mantle surface of the rotor, the peripheral edge of said first recess has a concavity which faces towards said peripheral edge, and a second recess which forms a radially extending slot which extends from a point close to the concavity and out towards said peripheral edge, a bridge is formed between the first recess and the second recess, and the second recess has a widened part which is located between the concavity of the first recess and the peripheral edge.