Abstract: An uninterruptible power supply unit for subsea applications includes a flow battery including: at least one flow battery module including at least a negative electrode cell and a positive electrode cell, a first electrolyte storage tank connected to the negative electrode cell to provide the negative electrode cell with a first electrolyte, and a second electrolyte storage tank connected to the positive electrode cell to provide the positive electrode cell with a second electrolyte. The unit further includes at least one electrolyte pressure compensator, connected to the first electrolyte storage tank and connected to the second electrolyte storage tank, respectively, to provide pressure balancing between an ambient medium surrounding the at least one electrolyte pressure compensator and first electrolytes and second electrolytes inside the first electrolyte storage tank and inside the second electrolyte storage tank, respectively.

Abstract: An uninterruptible power supply unit for subsea applications includes a flow battery including: at least one flow battery module including at least a negative electrode cell and a positive electrode cell, a first electrolyte storage tank connected to the negative electrode cell to provide the negative electrode cell with a first electrolyte, and a second electrolyte storage tank connected to the positive electrode cell to provide the positive electrode cell with a second electrolyte. The unit further includes at least one electrolyte pressure compensator, connected to the first electrolyte storage tank and connected to the second electrolyte storage tank, respectively, to provide pressure balancing between an ambient medium surrounding the at least one electrolyte pressure compensator and first electrolytes and second electrolytes inside the first electrolyte storage tank and inside the second electrolyte storage tank, respectively.

Abstract: A method is disclosed for supporting a capacitor. In an embodiment, the method includes applying a pressure on a first side of the capacitor parallel to a first electrode of the capacitor in a first direction of a normal of the first electrode; applying a pressure on a second side of the capacitor parallel to a second electrode of the capacitor in a second direction of a normal of the second electrode, the first direction being opposite to the second direction; and afterwards pressurizing a non-conductive fluid surrounding the capacitor to a target pressure.

Abstract: A subsea converter includes an outer housing, configured to be in contact with the subsea water when the converter is installed subsea, and an inner housing provided inside the outer housing. The inner housing is fluid tight sealed against the outer housing. Further, at least one first electric component is located inside the outer housing but outside the inner housing. The outer housing is filled with a first dielectric fluid and at least one capacitor is located inside the inner housing. Finally, the inner housing is filled with a second dielectric fluid, the second dielectric fluid having a lower moisture content than the first dielectric fluid.

Abstract: A capacitor support system includes a support structure configured to support at least one capacitor and a pressure generating module configured to generate a pressure on the at least one capacitor. The pressure generating module includes a bearing plate, a transmission plate, and at least one plate shaped leaf spring provided between the bearing plate and the pressure transmission plate. The pressure generating module is connected to the support structure by the bearing plate. The bearing plate is fixedly connected to the connecting structure in such a way that it provides a bearing surface for the at least one leaf spring and keeps the at least one leaf spring in a compressed state between the bearing plate and the at least one capacitor.

Abstract: A system and a method are disclosed for controlling a charging level of at least one capacitor. In an embodiment, the system includes a sound wave sensor configured to detect sound signals from the capacitors; a sound evaluation unit configured to evaluate the sound signals detected by the sound wave sensor; and a control unit configured to control the charging level of the at least one capacitor. Thereby the control unit is configured to control the charging level of the at least one capacitor in dependence on the sound signals evaluated by the sound evaluation unit and to reduce the charging level of the capacitors if defined criteria are met in patterns of the sound signals.

Abstract: A subsea power supply arrangement includes a closed power supply module realized to contain a pressure-compensated main fluid volume; and a number of power cell arrangements arranged in the interior of the closed power supply module. At least one power cell arrangement includes a metal capacitor housing realized to contain a capacitor bank in a fluid volume, and a barrier between an interior fluid volume of the power cell arrangement and the main fluid volume. A subsea power cell arrangement for use in such a subsea power supply arrangement is also disclosed.

Abstract: A subsea converter includes an outer housing, configured to be in contact with the subsea water when the converter is installed subsea, and an inner housing provided inside the outer housing. The inner housing is fluid tight sealed against the outer housing. Further, at least one first electric component is located inside the outer housing but outside the inner housing. The outer housing is filled with a first dielectric fluid and at least one capacitor is located inside the inner housing. Finally, the inner housing is filled with a second dielectric fluid, the second dielectric fluid having a lower moisture content than the first dielectric fluid.

Abstract: A pressure compensator for a subsea device is provided. The pressure compensator provides pressure balancing between a chamber of the subsea device and the surrounding environment when the subsea device is installed at a subsea location. The pressure compensator includes an intermediate compensation chamber that is provided by a compensator enclosure. The compensator enclosure is sealed against the subsea environment. The compensator enclosure includes a bellows portion that is deformable to change the volume of the intermediate compensation chamber. The pressure compensator further includes a flexible hose disposed inside the intermediate compensation chamber. A volume inside the flexible hose provides a main compensation chamber.

Abstract: A subsea switchgear for switching the power supply to plural subsea loads includes a subsea enclosure, to allow the deployment of the subsea switchgear at a subsea location; a power input for receiving AC electrical power from a power source; at least two power outputs for giving out AC electrical power; and a power distribution bus for distributing the received AC electrical power to the at least two power outputs. In at least one embodiment, between each power output and the power distribution bus, a contactor is connected which is controllable to connect or disconnect the respective power output from the power distribution bus.

Abstract: A subsea converter module is provided. A subsea enclosure is configured to provide a fluid tight sealing of the inside of the subsea enclosure to the outside of the subsea enclosure. At least one converter unit for providing frequency conversion of AC electrical power is disposed in the subsea enclosure. The subsea enclosure includes a mounting portion for mounting the subsea converter module to a base module of a subsea converter. The subsea enclosure includes an end wall that provides separation towards the base module when the subsea converter module is mounted to the base module.

Abstract: A subsea switchgear for switching the power supply to plural subsea loads includes a subsea enclosure, to allow the deployment of the subsea switchgear at a subsea location; a power input for receiving AC electrical power from a power source; at least two power outputs for giving out AC electrical power; and a power distribution bus for distributing the received AC electrical power to the at least two power outputs. In at least one embodiment, between each power output and the power distribution bus, a contactor is connected which is controllable to connect or disconnect the respective power output from the power distribution bus.

Abstract: A method for treating a capacitor for healing faults therein includes: applying a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure; and pressurizing a non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.

Abstract: A capacitor support system includes a support structure configured to support at least one capacitor and a pressure generating module configured to generate a pressure on the at least one capacitor. The pressure generating module includes a bearing plate, a transmission plate, and at least one plate shaped leaf spring provided between the bearing plate and the pressure transmission plate. The pressure generating module is connected to the support structure by the bearing plate. The bearing plate is fixedly connected to the connecting structure in such a way that it provides a bearing surface for the at least one leaf spring and keeps the at least one leaf spring in a compressed state between the bearing plate and the at least one capacitor.

Abstract: A subsea power supply arrangement includes a closed power supply module realized to contain a pressure-compensated main fluid volume; and a number of power cell arrangements arranged in the interior of the closed power supply module. At least one power cell arrangement includes a metal capacitor housing realized to contain a capacitor bank in a fluid volume, and a barrier between an interior fluid volume of the power cell arrangement and the main fluid volume. A subsea power cell arrangement for use in such a subsea power supply arrangement is also disclosed.

Abstract: A pressure compensator for a subsea device is provided. The pressure compensator provides pressure balancing between a chamber of the subsea device and the surrounding environment when the subsea device is installed at a subsea location. The pressure compensator includes an intermediate compensation chamber that is provided by a compensator enclosure. The compensator enclosure is sealed against the subsea environment. The compensator enclosure includes a bellows portion that is deformable to change the volume of the intermediate compensation chamber. The pressure compensator further includes a flexible hose disposed inside the intermediate compensation chamber. A volume inside the flexible hose provides a main compensation chamber.

Abstract: A method is disclosed for supporting a capacitor. In an embodiment, the method includes applying a pressure on a first side of the capacitor parallel to a first electrode of the capacitor in a first direction of a normal of the first electrode; applying a pressure on a second side of the capacitor parallel to a second electrode of the capacitor in a second direction of a normal of the second electrode, the first direction being opposite to the second direction; and afterwards pressurizing a non-conductive fluid surrounding the capacitor to a target pressure.

Abstract: A subsea fuse assembly adapted to be operated in a pressurized environment is provided. The subsea fuse assembly includes an enclosure having a first hollow part and a second part which is a rigid supporting wall. The first part of the enclosure is mounted and sealed to the rigid supporting wall such that the first part of the enclosure and the rigid supporting wall enclose a chamber that is sealed in a liquid-tight manner to a surrounding pressurized environment. A fuse element is arranged inside the chamber. A first electrical terminal and a second electrical terminal are arranged in the rigid supporting wall for leading an electrical connection through the supporting wall for electrically contacting the fuse element. The first part of the enclosure includes at least a flexible portion configured to allow the first part of the enclosure to expand and contract to change the volume of the chamber.

Abstract: A contactor arrangement for operation in a dielectric liquid environment may include a first connection terminal and a second connection terminal, a contactor having a fixed contact, and a movable contact that is movable relative to the fixed contact, the contactor having an open state in which the movable contact is spaced apart from the fixed contact and a closed state in which the movable contact is in contact with the fixed contact so as to provide an electric connection through the contactor via the movable contact. The contactor arrangement may further include a conductor section.

Abstract: A method for treating a capacitor for healing faults therein includes: applying a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure; and pressurizing a non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.