DC voltage converting device having a plurality of DC voltage converting units connected in series on an input side and in parallel on an output side

• US 7,759,827 B2
• Filed: 09/18/2002
• Issued: 07/20/2010
• Est. Priority Date: 09/19/2001
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Cameron International Corporation (Schlumberger NV)
• Inventors: Biester, Klaus, Kunow, Peter
• Primary Examiner(s): Paladini; Albert W
• Assistant Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US10/489,533
• Publication Number:
  US 20040262998A1
• Time in Patent Office: 2,862 Days
• Field of Search: 307/45, 307/63, 307/143, 307/147, 307/154, 363/71, 166/65.1, 166/335, 166/368
• US Class Current: 307/147
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10

Abstract

A DC voltage converting device is on the output side connected to a DC voltage source and, on the output side, supplies a converted DC voltage to at least one electrical consumer via a cable connection. To improve such a DC voltage converting device in that also with high DC voltages on the input side, a conversion into another DC voltage is possible without any special constructional efforts and high costs while complicated cooling means or the like, are avoided at the same time, the Dc voltage converting device comprises a plurality of DC voltage converting units of which each is serially connected to the DC voltage source on the input side and connected in parallel with the cable connection on the output side for supplying the converted DC voltage.

Claims

1. A system for supplying power from a DC source above sea level to an electrical device disposed in the sea water, the system comprising:

a plurality of DC/DC converters disposed in the sea water, wherein inputs of the DC/DC converters are connected to the DC source via an electrical conductor and wherein outputs of the DC/DC converters provide a converted DC voltage to the subsea electrical device,

wherein the plurality of subsea DC/DC converters receive a high DC voltage from the DC source via the electrical conductor and convert the high DC voltage to a lower DC voltage,

wherein the DC/DC converters are in a spaced relationship with each other such that heat from the DC/DC converters is dissipated using only environment cooling.

2. The system of claim 1 further comprising a controller coupled to each of the DC/DC converters to regulate one or more functions of each DC/DC converter and to specifically identify failed DC/DC converters.

3. The system of claim 2 wherein the controller is coupled to the electrical device to regulate one or more operations of the electrical device.

4. The system of claim 3 further comprising a data coupling device coupled to the electrical conductor and the controller, wherein the data coupling device is operable to decouple data from the electrical device and provide the data to the controller while power is supplied to the electrical device.

5. The system of claim 4 wherein the data coupling device couples data from the controller to the electrical conductor while power is supplied to the electrical device.

6. The system of claim 3 wherein the controller detects a failure of a DC/DC converter and causes other DC/DC converters to compensate for the failed DC/DC converter.

7. The system of claim 2 wherein the controller independently controls an output power of each DC/DC converter.

8. The system of claim 7 wherein each DC/DC converter comprises a switching mechanism that permits the output power of each DC/DC converter to be controlled using a pulse width modulated signal.

9. The system of claim 5 wherein the data decoupled from the electrical conductor is used to control the electrical device.

10. The system of claim 5 wherein the data coupled to the electrical conductor is used to monitor the electrical device.

11. The system of claim 5 wherein the data coupled to the electrical conductor is used to monitor the DC/DC converters.

12. The system of claim 1 further comprising a filter coupled between the DC source and the DC/DC converters, wherein a frequency range up to 50 kHz is filtered by the filter and wherein the filtered frequencies are used for communications to the DC source.

13. The system of claim 1 wherein the electrical device is an actuator to control a fluid flow in a fluid line.

14. The system of claim 1 wherein the electrical conductor is a coaxial cable.

15. The system of claim 14 wherein the electrical conductor is under water and has a length in the range of 2 to 60 kilometers.

16. The system of claim 14 wherein the electrical conductor is at least two kilometers in length.

17. A system for supplying power from a sea surface to a subsea location, the system comprising:

an DC source for disposal at the sea surface;

a subsea electrical device;

a plurality of DC voltage converters for disposal subsea, each having an input side connected to the DC source via an electrical conductor and an output side connected to the subsea electrical device; and

a controller which detects a failure of a DC converter and causes other DC converters to compensate for the failed DC converter.

18. The system of claim 17 wherein the electrical conductor extends subsea to the subsea electrical device and wherein the electrical conductor has a small cross-section designed to support up to 10 kV of DC voltage and at least 3 amperes of current.

19. The system of claim 17 wherein a frequency filter is placed between the DC source and the input side of each DC voltage converter to filter a frequency range up to 50 kHz and wherein the filtered frequencies are used for communications to the DC source.

20. The system of claim 17 wherein the DC converters are in a spaced relationship with each other such that heat from the DC converters is dissipated without the need of a cooling component.

21. A system for supplying from a DC source above sea level to a remote subsea location, the system comprising:

a plurality of underwater DC voltage converting units serially connected on an input side to the DC source via a subsea cable, the plurality of DC voltage converting units convert a first DC voltage to a second DC voltage for output to an underwater actuator controlling fluid flow through a fluid line; and

a controller which detects a failure of a DC voltage converter unit and causes other DC voltage converter units to compensate for the failed DC voltage converter unit.