A subsea pressure compensation arrangement is disclosed as having a vessel filled with insulating fluid, and a pressure compensator for compensating pressure variations of the insulating fluid. The arrangement can include a fluid connection pipe for fluid communication between the vessel and the pressure compensator, wherein the fluid connection pipe is connected to a bottom wall of the pressure compensator. A pipe opening arranged at an end of the fluid connection pipe extends above a level of the bottom wall of the pressure compensator.

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.

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.

A modular subsea converter for providing a frequency conversion of AC electric power is provided. The modular subsea converter includes at least one base module having a subsea enclosure and electrical connections disposed within the subsea enclosure. It further includes at least one converter module having a converter unit. The converter module is coupled to the base module and has a subsea enclosure in which the converter unit is disposed. The electrical connections of the base module are coupled to the converter unit of the converter module and the subsea enclosure of the converter module is mounted to the subsea enclosure of the base module.

A power converter includes an outer housing formed of dielectric material and including a low voltage compartment and a high voltage compartment is disclosed. The power converter also includes a low voltage DC-to-AC converter disposed in the low voltage compartment, a first coil in the low voltage compartment, a first conductive shield element lining an outer wall of the low voltage compartment, the first conductive shield element being electrically coupled to an electrical input of the DC-to-AC converter and a second conductive shield element lining an outer wall of the high voltage compartment.

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.

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.

An electric converter system, including a housing configured to receive a dielectric fluid, at least two electric modules, each including a first space and a second space, the first space including a connecting portion and a cooling system configured to circulate the dielectric fluid to cool the electric modules. The converter system further includes an inter module bus bar portion including a complementary connecting portion, whereby the connecting portion is configured to be connected to the complementary connecting portion of the inter module bus bar portion, whereby the inter module bus bar portion is configured to interconnect one of the at least two electric modules with the other of the at least two electric modules, said one electric module being proximate to said other electric module, and whereby the connecting portion, the first space and the second space of each electric module are arranged in series.

A subsea cooling assembly has a block module for the accommodation of electronics or power components and a cover element. The block module is arranged with at least one recess, with the electronics or power components being arranged in the at least one recess of the block module for the transfer heat between the electronics or power components and the surrounding sea through the block module. The cover element has outer rim portions arranged to fit with outer rim portions of the at least one recess for closing off the interior of the at least one recess. The block module has at least one strength supporting structure arranged to provide load support to at least a portion of the cover element which is distanced away from the outer rim portions of the cover element.

An arrangement for cooling components of a subsea electric system including a tank filled with a dielectric fluid. The tank includes first and second sections. The arrangement includes one first electric component within the first section, and one second electric component within the second section. The arrangement includes a first heat exchanger located outside the tank and in fluid contact with the tank, and arranged during operation to be in thermal contact with sea water. The arrangement includes a pump arranged to force a flow of dielectric fluid through the first heat exchanger. Flow of dielectric fluid in the tank is by both natural and forced convection generated by the pump. The first electric component generates more heat than the second electric component. Within the first section the share of the flow by natural convection is greater than within the second section.