Abstract: An arrangement for an overvoltage protection of a subsea electrical apparatus and a method for operating it. The arrangement includes a tank submersible below a water surface level, an electrical apparatus accommodated in the tank, and a surge arrester arrangement accommodated in the tank and coupled to a power supply of the electrical apparatus in the tank for providing the overvoltage protection of the electrical apparatus. The arrangement further includes a controllable grounding switch for connecting the surge arrester arrangement to a ground point in response to a control of the grounding switch to a closed state and for disconnecting the surge arrester arrangement from the ground point in response to a control of the grounding switch to an open state.

Abstract: A heat exchanging arrangement for a subsea electronic system, the heat exchanging arrangement including a wall section; a corrugation formed in the wall section, the corrugation having two generally opposing internal corrugation surfaces; and at least one heat exchanging element forced against at least one of the internal corrugation surfaces. A subsea electronic system including a heat exchanging arrangement is also provided.

Abstract: A heat exchanging arrangement for a subsea electronic system, the heat exchanging arrangement including: at least one pipe having an external surface; and at least one heat exchanging element arranged inside the at least one pipe and defining at least one internal passage for conducting a dielectric fluid through the at least one pipe; wherein the at least one heat exchanging element is arranged to press laterally outwards against an internal surface of the at least one pipe to establish a heat transfer bond between the at least one heat exchanging element and the at least one pipe. A subsea electronic system including the heat exchanging arrangement is also provided.

Abstract: An arrangement for an overvoltage protection of a subsea electrical apparatus and a method for operating it. The arrangement includes a tank submersible below a water surface level, an electrical apparatus accommodated in the tank, and a surge arrester arrangement accommodated in the tank and coupled to a power supply of the electrical apparatus in the tank for providing the overvoltage protection of the electrical apparatus. The arrangement further includes a controllable grounding switch for connecting the surge arrester arrangement to a ground point in response to a control of the grounding switch to a closed state and for disconnecting the surge arrester arrangement from the ground point in response to a control of the grounding switch to an open state.

Abstract: An arrangement for subsea cooling of a semiconductor module. The arrangement includes a tank. The tank is filled with a dielectric fluid. The arrangement includes at least one semiconductor module. The at least one semiconductor module is placed in the tank. Each at least one semiconductor module includes semiconductor submodules and is attached to a heat sink. The semiconductor submodules generate heat, thereby causing the dielectric fluid to circulate by natural convection. The heat sink includes a first part having a first thermal resistance from the semiconductor module to the dielectric fluid. The heat sink includes a second part having a second thermal resistance from the semiconductor module to the dielectric fluid. The second thermal resistance is higher than the first thermal resistance. The heat sink is oriented such that, when the arrangement is installed, the first part is configured to lie vertically higher than the second part.

Abstract: A heat exchanging arrangement for a subsea electronic system, the heat exchanging arrangement including: at least one pipe having an external surface; and at least one heat exchanging element arranged inside the at least one pipe and defining at least one internal passage for conducting a dielectric fluid through the at least one pipe; wherein the at least one heat exchanging element is arranged to press laterally outwards against an internal surface of the at least one pipe to establish a heat transfer bond between the at least one heat exchanging element and the at least one pipe. A subsea electronic system including the heat exchanging arrangement is also provided.

Abstract: A heat exchanging arrangement for a subsea electronic system, the heat exchanging arrangement including a wall section; a corrugation formed in the wall section, the corrugation having two generally opposing internal corrugation surfaces; and at least one heat exchanging element forced against at least one of the internal corrugation surfaces. A subsea electronic system including a heat exchanging arrangement is also provided.

Abstract: A pressure compensated subsea arrangement for housing of electric components. The arrangement includes a pressure compensated housing. The pressure compensated housing is filled with a dielectric liquid. The arrangement includes at least one electric component. The at least one electric component is provided inside the pressure compensated housing. The dielectric liquid is a hydrocarbon dielectric liquid including isoparaffin. There is also provided a method of manufacturing such an arrangement.

Abstract: A power capacitor unit for high-pressure applications is provided. The power capacitor unit includes a housing, a plurality of capacitor elements connected to each other and arranged inside the housing, a dielectric liquid (L), a solid electrical insulation system arranged to electrically insulate each capacitor element, a busbar, a plurality of fuse wires, each fuse wire having a first end connected to a respective capacitor element and a second end connected to the busbar (B), wherein the capacitor elements, the solid electrical insulation system, and the fuse wires are immersed in the dielectric liquid (L). Each fuse wire has a plurality of first sections that are in physical contact with the electrical insulation system, and wherein each fuse wire has a plurality of second sections without physical contact with the solid electrical insulation system.

Abstract: A pressure compensated subsea electrical system and a pressure compensated subsea electrical system which has a housing filled with a dielectric liquid. The housing has a first housing portion and a second housing portion in pressure communication with each other. The first housing portion includes a transformer, and the second housing portion includes a power converter. The pressure compensated subsea electrical system includes a pressure compensator arranged to compensate pressure inside the housing. The pressure compensator is enabled to compensate pressure in both the first housing portion and the second housing portion.

Abstract: A fluid-cooled stator assembly for electrical machines. The stator assembly may include a stator core having a back iron portion and a plurality of stator teeth. Each of the plurality of stator teeth may be separated from each other by at least one of plurality of slots, the slots being structured to receive placement of stator windings. The apparatus also includes a thermal management conduit that is positioned at various locations about the stator assembly, including within or along the back iron portion, stator teeth, slots, and/or among the stator windings. Further, the thermal management conduit may provide insulation for one or more coils of the stator windings. Additionally, at least a portion of the thermal management conduit may be formed from a thermally conductive polymer. The thermal management conduit is configured to convey a thermal management fluid in a heat exchange relationship with the stator assembly.

Abstract: A power capacitor unit for high-pressure applications is provided. The power capacitor unit includes a housing, a plurality of capacitor elements connected to each other and arranged inside the housing, a dielectric liquid (L), a solid electrical insulation system arranged to electrically insulate each capacitor element, a busbar, a plurality of fuse wires, each fuse wire having a first end connected to a respective capacitor element and a second end connected to the busbar (B), wherein the capacitor elements, the solid electrical insulation system, and the fuse wires are immersed in the dielectric liquid (L). Each fuse wire has a plurality of first sections that are in physical contact with the electrical insulation system, and wherein each fuse wire has a plurality of second sections without physical contact with the solid electrical insulation system.

Abstract: A power electronics module includes: a baseplate, a power semiconductor chip arranged on the baseplate, and an encapsulation structure arranged on the baseplate and configured to encapsulate the power semiconductor chip, wherein the encapsulation structure is an epoxy having an elastic modulus in a range of 1 to 20 Giga Pascal, GPa, at room temperature and a coefficient of thermal expansion less than 20 ppm/K.

Abstract: A pressure compensated subsea arrangement for housing of electric components. The arrangement includes a pressure compensated housing. The pressure compensated housing is filled with a dielectric liquid. The arrangement includes at least one electric component. The at least one electric component is provided inside the pressure compensated housing. The dielectric liquid is a hydrocarbon dielectric liquid including isoparaffin. There is also provided a method of manufacturing such an arrangement.

Abstract: The present disclosure relates to a high voltage power electronics module for subsea applications. The power electronics module includes: a baseplate, a power semiconductor chip arranged on the baseplate, and an encapsulation structure arranged on the baseplate and configured to encapsulate the power semiconductor chip, wherein the encapsulation structure is an epoxy having an elastic modulus less in a range of 1 to 20 Giga Pascal, GPa, at room temperature and a coefficient of thermal expansion less than 20 ppm/K.

Abstract: A pressure compensated subsea electrical system and a pressure compensated subsea electrical system which has a housing filled with a dielectric liquid. The housing has a first housing portion and a second housing portion in pressure communication with each other. The first housing portion includes a transformer, and the second housing portion includes a power converter. The pressure compensated subsea electrical system includes a pressure compensator arranged to compensate pressure inside the housing. The pressure compensator is enabled to compensate pressure in both the first housing portion and the second housing portion.

Abstract: An arrangement for subsea cooling of a semiconductor module. The arrangement includes a tank. The tank is filled with a dielectric fluid. The arrangement includes at least one semiconductor module. The at least one semiconductor module is placed in the tank. Each at least one semiconductor module includes semiconductor submodules and is attached to a heat sink. The semiconductor submodules generate heat, thereby causing the dielectric fluid to circulate by natural convection. The heat sink includes a first part having a first thermal resistance from the semiconductor module to the dielectric fluid. The heat sink includes a second part having a second thermal resistance from the semiconductor module to the dielectric fluid. The second thermal resistance is higher than the first thermal resistance. The heat sink is oriented such that, when the arrangement is installed, the first part is configured to lie vertically higher than the second part.

Abstract: For identifying the machine type of an alternating current machine, a direct current is first applied to the stator for aligning the d-axis of the rotor and the magnetic field direction of the stator. Secondly, a direct current is applied to the stator at a current angle which causes the rotors of a permanent magnet machine and a synchronous reluctance machine to exert torque in different directions. The torque direction of the rotor is detected and the machine type is identified based on the torque direction information. The machine type is recognized as a permanent magnet machine or a synchronous reluctance machine depending on the torque direction. If no torque is detected, then the machine type is recognized as an induction machine.

Abstract: A fluid-cooled stator assembly for electrical machines. The stator assembly may include a stator core having a back iron portion and a plurality of stator teeth. Each of the plurality of stator teeth may be separated from each other by at least one of plurality of slots, the slots being structured to receive placement of stator windings. The apparatus also includes a thermal management conduit that is positioned at various locations about the stator assembly, including within or along the back iron portion, stator teeth, slots, and/or among the stator windings. Further, the thermal management conduit may provide insulation for one or more coils of the stator windings. Additionally, at least a portion of the thermal management conduit may be formed from a thermally conductive polymer. The thermal management conduit is configured to convey a thermal management fluid in a heat exchange relationship with the stator assembly.

Abstract: A cooling system for a brushed electrical machine includes a cooler configured to cool down a rotor and a commutator of the machine. There is a controller configured to adjust the cooling effect of the cooler in response to monitored rotor and commutator temperatures. The cooler includes a fan and an auxiliary motor configured to rotate the fan.