Abstract: A method is provided for transferring electrical power. AC power is generated and guided at least partially underwater. The AC power is guided through a cable from a first end of the cable to a second end of the cable. A frequency of the AC power guided through the cable is adjusted in dependence of a length of the cable between the first end and the second end of the cable.

Abstract: A stored electric energy distribution arrangement for distribution of stored electric energy on a vessel having one or more AC consumers, in the event of failure of a primary electric energy supply to the AC consumers has a DC-circuit. The DC circuit has a plurality of backup electric energy storage elements connected in a ring, for supplying stored electric energy to one or more AC consumers in the event of failure of the primary electric energy supply. A plurality of breaker systems are provided in the DC circuit for disconnecting one or more backup electric energy storage elements from the DC-circuit, in the event of a fault associated with that backup element.

Abstract: It is described a switching device comprising a semiconductor switching unit; a contactor electrically coupled in series with the semiconductor switching unit; and a controller being configured for activating an electrically isolating state of the switching device and/or activating an electrically conducting state of the switching device based on a command signal or based on a comparison of a measured value and predetermined activation condition.

Abstract: Methods for transferring electrical power in the sea include: generating AC power; and guiding, at least partially underwater, the AC power through a cable from a first end of the cable to a second end of the cable. A first reactor is connected near the first end of the cable and a second reactor is connected near the second end of the cable. Inductances of the first reactor and the second reactor are selected to at least partially compensate for reactive power generated in the cable.

Abstract: A method for transferring electrical power in the sea includes generating AC power, guiding, at least partially underwater, the AC power through a cable from a first end of the cable to a second end of the cable, and changing a frequency of the AC power guided through the cable based on a value of power consumption of a load connected to the second end of the cable.

Abstract: An arrangement for providing a variable volume size is described. The arrangement includes an outer bellow having an outer end wall closing the outer bellow at one end. The arrangement further includes an inner bellow having an inner end wall closing the inner bellow at one end, the inner bellow being arranged at least partly inside the outer bellow. The arrangement further includes a base at which another end of the outer bellow and another end of the inner bellow are attached. The arrangement further includes a position measuring apparatus for measuring at least one position indicative of a distance between the outer end wall and the inner end wall.

Abstract: A subsea transformer that includes a transformer and a transformer tank adapted to accommodate the transformer is provided. The transformer tank has an opening that is sized so as to enable insertion of the transformer into the transformer tank through the opening. A closing plate is adapted to close the opening of the transformer tank. At least one component having a double barrier against ingress of an ambient medium surrounding the subsea transformer when installed subsea is mounted to the closing plate.

Abstract: A subsea transformer enclosure is provided. A transformer chamber of the subsea transformer enclosure is adapted to receive a transformer. A pressure compensation device is mounted to the transformer chamber and is adapted to provide pressure balancing between a dielectric liquid in the transformer chamber and an ambient medium surrounding the subsea transformer enclosure. A bushing chamber is further mounted to the transformer chamber, and a liquid tight seal is provided between the interior of the bushing chamber and the interior of the transformer chamber. The pressure compensation device includes first and second pressure compensators.

Abstract: A subsea fuse assembly is provided. The subsea fuse assembly is adapted to be operated in a pressurized environment. The subsea fuse assembly includes an enclosure adapted to be filled with a dielectric liquid, and a pressure compensator including a flexible element for pressure compensation. The subsea fuse assembly also includes a first penetrator and a second penetrator each passing through a wall of the enclosure for leading a first electric conductor and a second electric conductor, respectively, into the enclosure. The subsea fuse assembly includes a fuse arranged inside the enclosure and connected between the first electric conductor and the second electric conductor.

Abstract: An arrangement for providing a variable volume size is described. The arrangement includes an outer bellow having an outer end wall closing the outer bellow at one end. The arrangement further includes an inner bellow having an inner end wall closing the inner bellow at one end, the inner bellow being arranged at least partly inside the outer bellow. The arrangement further includes a base at which another end of the outer bellow and another end of the inner bellow are attached. The arrangement further includes a position measuring apparatus for measuring at least one position indicative of a distance between the outer end wall and the inner end wall.

Abstract: An arrangement for controlling a synchronous generator having a stator comprising at least one stator winding and having a rotor with an electromagnet driven by a field current is provided. The rotor is rotatable relative to the stator. The electromagnet is inductively coupled to the at least one stator winding. The arrangement includes a measurement system configured to measure at least one quantity and a controller configured to cause shutting down the field current when the at least one quantity satisfies at least one criterion associated with at least one malfunction.

Abstract: It is described an arrangement for providing an AC current to a load for direct electrical heating, the arrangement comprising a AC-DC-AC converter cell (133, 433, 533, 633, 733), the converter cell having at least two converter input terminals (111, 112, 113) connected to at least two transformer output terminals, the converter cell having a first converter output terminal (135, 435, 535) and a second converter output terminal (137, 437, 537), wherein the first converter cell output terminal (135) is adapted to be connected to the load (350, 650, 750, 850).

Abstract: A subsea transformer that includes a transformer and a transformer tank adapted to accommodate the transformer is provided. The transformer tank has an opening that is sized so as to enable insertion of the transformer into the transformer tank through the opening. A closing plate is adapted to close the opening of the transformer tank. At least one component having a double barrier against ingress of an ambient medium surrounding the subsea transformer when installed subsea is mounted to the closing plate.

Abstract: A subsea fuse assembly is provided. The subsea fuse assembly is adapted to be operated in a pressurized environment. The subsea fuse assembly includes an enclosure adapted to be filled with a dielectric liquid, and a pressure compensator including a flexible element for pressure compensation. The subsea fuse assembly also includes a first penetrator and a second penetrator each passing through a wall of the enclosure for leading a first electric conductor and a second electric conductor, respectively, into the enclosure. The subsea fuse assembly includes a fuse arranged inside the enclosure and connected between the first electric conductor and the second electric conductor.

Abstract: A method is provided for transferring electrical power. AC power is generated and guided at least partially underwater. The AC power is guided through a cable from a first end of the cable to a second end of the cable. A frequency of the AC power guided through the cable is adjusted in dependence of a length of the cable between the first end and the second end of the cable.

Abstract: Methods for transferring electrical power in the sea include: generating AC power; and guiding, at least partially underwater, the AC power through a cable from a first end of the cable to a second end of the cable. A first reactor is connected near the first end of the cable and a second reactor is connected near the second end of the cable. Inductances of the first reactor and the second reactor are selected to at least partially compensate for reactive power generated in the cable.

Abstract: A method for transferring electrical power in the sea includes generating AC power, guiding, at least partially underwater, the AC power through a cable from a first end of the cable to a second end of the cable, and changing a frequency of the AC power guided through the cable based on a value of power consumption of a load connected to the second end of the cable.

Abstract: Short circuit safe rectifier stage for a subsea power grid It is described a rectifier stage (251) for converting an input AC voltage to an output voltage, the rectifier stage comprising: a first AC input terminal (255); a second AC input terminal (257), wherein the input AC voltage is applicable between the first input terminal and the second input terminal; a first DC output terminal (267); a second DC output terminal (268); a first thyristor (261) connected between the first DC output terminal (267) and the first AC input terminal (255); a second thyristor (263) connected between the first DC output terminal (267) and the second AC input terminal (257); a gate control circuit (272) adapted and connected to control a first conductance state of the first thyristor (261) and to control a second conductance state of the second thyristor (263) such that the first thyristor and the second thyristor provide a rectified AC voltage between the first DC output terminal (267) and the second DC output terminal (268) a

Abstract: A subsea fuse assembly is provided. The subsea fuse assembly is adapted to be operated in a pressurized environment. The subsea fuse assembly includes an enclosure adapted to be filled with a dielectric liquid, and a pressure compensator including a flexible element for pressure compensation. The subsea fuse assembly also includes a first penetrator and a second penetrator each passing through a wall of the enclosure for leading a first electric conductor and a second electric conductor, respectively, into the enclosure. The subsea fuse assembly includes a fuse arranged inside the enclosure and connected between the first electric conductor and the second electric conductor.

Abstract: It is described a switching device comprising a semiconductor switching unit; a contactor electrically coupled in series with the semiconductor switching unit; and a controller being configured for activating an electrically isolating state of the switching device and/or activating an electrically conducting state of the switching device based on a command signal or based on a comparison of a measured value and predetermined activation condition.