Subsea switchgear
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.
1. A subsea switchgear, comprising:
a subsea enclosure configured to allow the deployment of the subsea switchgear at a subsea location;
a power input to receive AC electrical power from a power source;
at least two power outputs to give out AC electrical power;
a power distribution bus to distribute the received AC electrical power to the at least two power outputs; and
a plurality of contactors, at least one of the plurality of contactors being connected between a respective one of the at least two power outputs and the power distribution bus, each of the plurality of contactors being controllable to connect or disconnect the respective one of the at least two power outputs from the power distribution bus wherein the plurality of contactors are solenoid contactors and wherein the plurality of contactors are submerged in a dielectric liquid.
2. The subsea switchgear of claim 1 , wherein the subsea switchgear is configured to provide power distribution for three phase AC electric power, wherein the power input is a three phase power input, wherein each of the at least two power outputs is a three phase power output, and wherein two or three contactors are provided for each of the at least two power outputs to allow connection or disconnection of two or three phases, respectively, of said at least two power outputs.
3. The subsea switchgear of claim 1 , wherein the plurality of contactors are located in a chamber filled with dielectric liquid.
4. The subsea switchgear of claim 1 , wherein the subsea switchgear comprises, for each of the at least two power outputs, a chamber in which the respective contactor for the respective one of the at least two power outputs is arranged and which is filled with dielectric liquid.
5. The subsea switchgear of claim 3 , wherein the chambers are provided by an intermediate enclosure located at least partly inside the subsea enclosure.
6. The subsea switchgear of claim 5 , wherein the intermediate enclosure comprises a flexible portion to provide pressure compensation between an inside of the intermediate enclosure and an inside of the subsea enclosure.
7. The subsea switchgear of claim 4 , wherein the chambers comprises the respective contactors for all phases of the respective one of the at least two power outputs.
8. The subsea switchgear of claim 1 , wherein the subsea enclosure comprises at least one of an output penetrator and an output connector for each one of the at least two power outputs.
9. The subsea switchgear of claim 1 , wherein the subsea enclosure comprises at least one of an input penetrator and an input connector for the power input.
10. The subsea switchgear of claim 1 , wherein the subsea switchgear is adapted to distribute AC electric power at a voltage level within the range of about 500 V to about 10,000 V.
11. The subsea switchgear of claim 1 , wherein the contactor is a no-load contactor adapted to be operated only when the power supply to the subsea switchgear is disconnected.
12. The subsea switchgear of claim 1 , wherein the subsea switchgear is configured to directly supply the AC electrical power received at the power input to the respective one of the at least two power outputs without any conversion.
13. The subsea switchgear of claim 1 , wherein the subsea switchgear does not include a power conversion device including a transformer or a frequency converter or a variable frequency drive.
14. The subsea switchgear of claim 1 , further comprising a control unit adapted to control the switching state of the plurality of contactors.
15. The subsea switchgear of claim 14 , wherein the control unit is configured to have a mode of operation to control the plurality of contactors so as to connect the power input subsequently to a different on of the at least two power outputs for an amount of time, while the remaining of the at least two power outputs are disconnected from the power input.
16. A pipeline heating system comprising:
the subsea switchgear of claim 1 ;
a plurality of heating units, each of the plurality of heating units being configured to heat a pipeline section, wherein a respective one of the heating units is connected to a respective one of the at least two power outputs of the subsea switchgear.
17. A subsea power distribution system for distributing electrical power to plural subsea loads, the plural subsea loads comprising electric motors, wherein the subsea power distribution system comprises the subsea switchgear of claim 1 .
18. The subsea switchgear of claim 2 , wherein the plurality of contactors are located in a chamber filled with an ester-based dielectric liquid or an oil.
19. The subsea switchgear of claim 3 , wherein the subsea switchgear comprises, for each of the at least two power outputs, a chamber in which the respective contactor for the respective one of the at least two power outputs is arranged and which is filled with an ester-based dielectric liquid or an oil.
20. The subsea switchgear of claim 6 , wherein the intermediate enclosure comprises a liquid tight or liquid permeable membrane as the flexible portion.
21. The subsea switchgear of claim 5 , wherein the chambers comprises the respective contactors for all phases of the respective one of the at least two power outputs.
22. The subsea switchgear of claim 6 , wherein the chambers comprises the respective contactors for all phases of the respective one of the at least two power outputs.
23. The subsea switchgear of claim 10 , wherein the subsea switchgear is adapted to distribute AC electric power at a voltage level within the range of about 1,000 V to about 7,000 V.
24. A pipeline heating system comprising:
the subsea switchgear of claim 2 ;
a plurality of heating units, each of the plurality of heating units being configured to heat a pipeline section, wherein a respective one of the heating units is connected to a respective one of the at least two power outputs of the subsea switchgear.
25. A pipeline heating system comprising:
the subsea switchgear of claim 3 ;
a plurality of heating units, each of the plurality of heating units being configured to heat a pipeline section, wherein a respective one of the heating units is connected to a respective one of the at least two power outputs of the subsea switchgear.
26. A pipeline heating system comprising:
the subsea switchgear of claim 4 ;
a plurality of heating units, each of the plurality of heating units being configured to heat a pipeline section, wherein a respective one of the heating units is connected to a respective one of the at least two power outputs of the subsea switchgear.
27. A pipeline heating system comprising:
the subsea switchgear of claim 5 ;
a plurality of heating units, each of the plurality of heating units being configured to heat a pipeline section, wherein a respective one of the heating units is connected to a respective one of the at least two power outputs of the subsea switchgear.
28. A subsea power distribution system for distributing electrical power to plural subsea loads, the plural subsea loads comprising electric motors, wherein the subsea power distribution system comprises the subsea switchgear of claim 2 .
29. A subsea power distribution system for distributing electrical power to plural subsea loads, the plural subsea loads comprising electric motors, wherein the subsea power distribution system comprises the subsea switchgear of claim 3 .
30. A subsea power distribution system for distributing electrical power to plural subsea loads, the plural subsea loads comprising electric motors, wherein the subsea power distribution system comprises the subsea switchgear of claim 4 .
31. A subsea power distribution system for distributing electrical power to plural subsea loads, the plural subsea loads comprising electric motors, wherein the subsea power distribution system comprises the subsea switchgear of claim 5 .
32. The subsea switchgear of claim 1 , wherein the subsea switchgear is for switching the power supply to a plurality of subsea loads.
33. The subsea switchgear of claim 2 , wherein the subsea switchgear is for switching the power supply to a plurality of subsea loads.
34. The subsea switchgear of claim 3 , wherein the subsea switchgear is for switching the power supply to a plurality of subsea loads.
35. A method of operating a subsea switchgear, comprising:
receiving AC electrical power at a power input;
distributing AC electrical power to two or more power outputs via a power distribution bus; and
switching power supply to the two or more power outputs via at least two contactors, each of the at least two contactors being connected between a respective one of the at least two power outputs and the power distribution bus, wherein the at least two contactors are solenoid contactors and wherein the at least two contactors are submerged in a dielectric liquid.