DC converter

• US 20040246753A1
• Filed: 08/05/2004
• Published: 12/09/2004
• Est. Priority Date: 09/19/2001
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Cooper Cameron Corporation (Schlumberger NV)
• Inventors: Biester, Klaus, Kunow, Peter
• Granted Patent: US 7,433,214 B2
• Time in Patent Office: Days
• US Class Current: 363/65
• 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 converter is connected to a DC source on its input side. On the output side, the DC delivers a converted DC voltage to at least one electric consumer via a cable connection. To improve such a DC converter in that it has a comparatively simple structural design and is able to reliably convert high DC voltages even in the case of high power, and in such a way that the reliability of the converter is increased and cooling systems entailing high costs can be dispensed with, the DC converter comprises a plurality of DC converter components, each of said DC components being, on the input side, serially connected to the DC source and, on the output side connected in parallel to the cable connection so as to provide the converted DC voltage for the electric consumer.

Claims

1. A DC converter connected to a DC source the DC converter delivers a converted voltage to at least one electric consumer via a cable connection, wherein the DC converters comprises:

a plurality of DC converter components, each of said DC converter components being, on an input side, serially connected to the DC source and, on the output side, connected in parallel to the cable connections so as to provide the converted DC voltage for the electric consumer.

2. A DC converter according to claim 1 wherein each DC converter components is implemented as a clocked switched mode power supply.

3. A DC converter according to claim 2 wherein the switch mode power supply has on the input side thereof a load which is connected in parallel to a transmitter of said switched mode power supply.

4. A DC converter according to claim 3 wherein the load is a Zener diode.

5. A DC converter according to claim 4 wherein the Zener diode comprises semiconductor elements,

6. A DC converter according to claim 2 wherein the switched mode power supply is clocked on the primary side.

7. A DC converter according to claim 2 wherein the switched mode power supply is implemented as a push-pull converter.

8. A DC converter according to claim 7 wherein the switched mode power supply comprises at least one switching transistor.

9. A DC converter according to claim 8 wherein the at least one switching transistors of the push-pull converter is clocked in a push-pull mode with a clock cycle ratio of 1:

1.

10. A DC converter according to claim 2 wherein the switched mode power supplies of the DC converter are clocked synchronously.

11. A DC converter according to claim 2, wherein the switched mode power supplies of the DC converter are clocked in a phase-shifted mode.

12. A DC converter according to claim 11 wherein a respective clock phase shift of neighboring switched mode power supplies amounts to 1/n, where n is the number of switched mode power supplies of the DC converter.

13. A DC converter according to claim 1 wherein the cable connection comprises a coaxial cable connection.

14. A DC converter according to one claim 1 wherein the DC converter is provided with a filter preceding said DC converter on the input side thereof.

15. A DC converter according to claim 14 further comprising a data coupler/decoupler connected upstream of said filter in the direction of the DC source.

16. A DC converter according to claim 15 further comprising a controller that is associated with at least one of the components selected from the group consisting of the DC converter, the DC converting components, the filter, and the data coupler/decoupler.

17. A DC converter according to claim 4 wherein, in the case of failure of switched mode power supply, the voltage of each Zener diode is adapted to be varied so as to readjust the output voltage of each non-failed switched mode power supply.

18. A DC converter according to claim 8 wherein a clock cycle ratio of the at least one switching transistor can be varied by readjusting the output voltage of the switched mode power supply.

19. A DC converter according to claim 8 wherein, the switched mode power supply comprises a pulse modulator which is operable to outputs a series of variable pulses to clock the at least one switching transistor.

20. A system for supplying power to an electrical device, the system comprising:

a DC source;

a plurality of DC/DC converters, 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 are connected to the electrical device,

wherein the plurality of 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 without a cooling mechanism that is needed when an amount of DC/DC converters less than the plurality of DC/DC converters are implemented to convert the high DC voltage to the lower DC voltage, and

wherein an input side of each DC/DC converter comprises a resistive load to dissipate power when the electrical device is not consuming power.

21. The system of claim 20 wherein the resistive load is a zener diode.

22. The system of claim 20 wherein the electrical conductor is at least one kilometer in length.

23. The system of claim 20 further comprising a controller coupled to each of the DC/DC converters, wherein the controller is operable to regulate one or more functions of each DC/DC converter.

24. The system of claim 23 wherein the controller is further coupled to the remote electrical consumer, wherein the controller is operable to regulate one or more functions of the remote electrical consumer.

25. The system of claim 23 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 conductor and provide the data to the controller while power is supplied to the electrical device.

26. The system of claim 25 wherein the data coupling device is operable to coupled data from the controller to the electrical conductor while power is supplied to the electrical conductor.

27. The system of claim 23 wherein the controller is operable to detect failure of a DC/DC converter and cause functioning DC/DC converters to compensate for the failed DC/DC converter.

28. The system of claim 23 wherein the controller independently controls an output power of each DC/DC converter.

29. The system of claim 28 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.

30. The system of claim 26 wherein the data decoupled from the electrical conductor is used to control the electrical device.

31. The system of claim 26 wherein the data coupled to the electrical conductor is used to monitor the electrical device.

32. The system of claim 26 wherein the data coupled to the electrical device is used to monitor the DC/DC converters.

33. The system of claim 20 wherein the electrical device is an actuator.

34. The system of claim 20 wherein the electrical conductor is a coaxial cable.

35. The system of claim 20 wherein the electrical device is located below ground.

36. The system of claim 20 wherein the electrical device is located under water.

37. 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; and

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;

wherein an input side of each DC converter includes a resistive load to dissipate power when the subsea electrical device is not consuming power.

38. The system of claim 37 wherein the electrical conductor extends subsea to the subsea electrical device.

39. The system of claim 37 wherein the resistive load is a zener diode.

40. The system of claim 37 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.

41. The system of claim 37 further including a controller which detects a failure of a DC converter and causes other DC converters to compensate for the failed DC converter.

42. A system for supplying power to a remote electrical device, the system comprising:

a DC source;

a plurality of DC voltage converters each having an input serially connected to the DC source via a conductor and each having an output connected to the remote electrical device,

wherein an input side of each DC converter includes a resistive load to dissipate power when the remote electrical device is not consuming power; and

wherein the length of the conductor is at least one kilometer.