Apparatus for and methods of polyphase power conversion

• US 20070228837A1
• Filed: 03/31/2006
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Nielsen, Henning, Hjort, Thomas
• Granted Patent: US 7,456,524 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 7/155 using semiconductor devices only

Abstract

In one aspect, a polyphase power converter includes an input adapted to couple to a polyphase AC source, a positive DC output, and a negative DC output. The polyphase power converter also includes a first plurality of circuits and a second plurality of circuits. In one embodiment, each of the first plurality of circuits is adapted to receive a plurality of phases of the polyphase AC source and to produce a DC voltage at the positive DC output. Each of the second plurality of circuits is adapted to receive a plurality of phases of the AC source and to produce a DC voltage at the negative DC output. In one embodiment, the polyphase power converter includes a plurality of switching devices and each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from at least one of the plurality of circuits.

Claims

1. A polyphase power converter comprising:

an input adapted to couple to a polyphase AC source;

a positive DC output;

a negative DC output;

a first plurality of circuits each adapted to receive a plurality of phases of the polyphase AC source and to produce a DC voltage at the positive DC output; and

a second plurality of circuits each adapted to receive a plurality of phases of the polyphase AC source and to produce a DC voltage at the negative DC output.

2. The polyphase power converter of claim 1, wherein each of the first plurality of circuits is adapted to receive a different combination of phases than others of the first plurality of circuits.

3. The polyphase power converter of claim 2, wherein each of the second plurality of circuits is adapted to receive a different combination of phases than others of the second plurality of circuits.

4. The polyphase power converter of claim 1, wherein each of the plurality of circuits is adapted to receive DC power.

5. The polyphase power converter of claim 1, further comprising a neutral input and a neutral output, wherein the neutral input and the neutral output are connected to one another.

6. The polyphase power converter of claim 5, wherein the positive DC output, the negative DC output, and the neutral output are adapted to be coupled to an inverter.

7. The polyphase power converter of claim 6, wherein the polyphase power converter is included in an uninterruptible power supply.

8. The polyphase power converter of claim 1, further comprising a plurality of switching devices, wherein each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from at least one of the plurality of circuits.

9. The polyphase power converter of claim 8, wherein each of the first plurality of circuits and each of the second plurality of circuits includes a separate plurality of inputs including a first input adapted to couple to a first phase of the polyphase AC source and a second input adapted to couple to a second phase of the polyphase AC source.

10. The polyphase power converter of claim 9, wherein the first input and the second input of each of the first plurality of circuits and each of the second plurality of circuits are adapted to be coupled to the polyphase AC source by a separate controlled rectifier.

11. The polyphase power converter of claim 9, wherein each of the first plurality of circuits comprises a positive boost circuit, and wherein each of the second plurality of circuits comprises a negative boost circuit.

12. The polyphase power converter of claim 9, wherein each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from a different one of the first plurality of circuits and the second plurality of circuits.

13. The polyphase power converter of claim 8, wherein each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from at least one of the first plurality of circuits and one of the second plurality of circuits.

14. The polyphase power converter of claim 13, wherein each of the plurality of switching devices comprises a relay.

15. The polyphase power converter of claim 3, wherein a quantity of the first plurality of circuits and a quantity of the second plurality of circuits are both equal to a quantity of phases of the polyphase AC source to which the polyphase power converter is adapted to be coupled.

16. The polyphase power converter of claim 1, wherein a quantity of the first plurality of circuits and a quantity of the second plurality of circuits are both less than a quantity of phases of the polyphase AC source to which the power converter is adapted to be coupled.

17. A method of converting a polyphase AC input to a DC output comprising acts of:

coupling a first power converter circuit to a first combination of phases of the polyphase AC input;

coupling a second power converter circuit to a second combination of phases of the polyphase AC input;

coupling an output of the first power converter circuit to the DC output; and

coupling an output of the second power converter circuit to the DC output.

18. The method of claim 17, further comprising acts of:

isolating a first phase of the polyphase AC source from the first power converter circuit with a first switching device; and

isolating a second phase of the polyphase AC source from the second power converter circuit with a second switching device.

19. The method of claim 18, wherein the first switching device comprises a first controlled rectifier, and wherein the second switching device comprises a second controlled rectifier.

20. The method of claim 17, further comprising acts of

coupling a total of three or more power converter circuits to the polyphase AC input, wherein each of the power converter circuits is coupled to a different combination of phases of the polyphase AC source;

and

coupling an output of each of the three or more power converter circuits to the DC output.

21. The method of claim 20, wherein the first power converter circuit comprises a first boost circuit having a first input, wherein the second power converter circuit comprises a second boost circuit having a second input, wherein a third power converter circuit comprises a third boost circuit having a third input, and wherein the method further comprises acts of:

isolating the first input during a first part of a line cycle of the polyphase AC input;

isolating the second input during a second part of the line cycle; and

isolating the third input during a third part of the line cycle.

22. The method of claim 21, further comprising an act of coupling the first input and the second input to a phase of the polyphase AC input during a fourth part of the line cycle.

23. The method of claim 22, wherein the first boost circuit is a first positive boost circuit, and wherein the second boost circuit is a second positive boost circuit.

24. The method of claim 17, wherein the first combination and the second combination are the same combination of phases of the polyphase AC source, wherein the method further comprises an act of isolating a phase of the polyphase AC source from each of the first power converter circuit and the second power converter circuit with a switching device.

25. The method of claim 24, wherein the first power converter circuit comprises a positive boost circuit and the second power converter circuit comprises a negative boost circuit, and wherein the switching device is a relay.

26. The method of claim 17, wherein the first combination and the second combination are the same combination of phases of the polyphase AC input, wherein the method further comprises acts of:

coupling a total of two or more power converter circuits to the polyphase AC input, wherein each of the power converter circuits is coupled to all of the phases of the polyphase AC source; and

coupling an output of each of the two or more power converter circuits to the DC output.

27. The method of claim 17, further comprising an act of simultaneously drawing power from a phase of the polyphase AC input by both the first power converter circuit and the second power converter circuit for at least a part of a line cycle of the polyphase AC input.

28. The method of claim 27, further comprising an act of simultaneously drawing power from the phase of the polyphase AC input by both the first power converter circuit and the second power converter circuit for a majority of the line cycle of the polyphase AC input.

29. A polyphase power converter comprising:

an input adapted to couple to a polyphase AC source;

a positive DC output;

a negative DC output;

a first plurality of circuits each with means for receiving a plurality of phases of the polyphase AC source, wherein the first plurality of circuits are adapted to produce a DC voltage at the positive DC output; and

a second plurality of circuits each with means for receiving a plurality of phases of the polyphase AC source, wherein the second plurality of circuits are adapted to produce a DC voltage at the negative DC output.

30. The polyphase power converter of claim 29, wherein each of the first plurality of circuits and each of the second plurality of circuits comprises a separate boost circuit, and wherein the means include switching means adapted to isolate at least one phase of the polyphase AC source from at least one of the plurality of circuits among the first plurality of circuits and the second plurality of circuits.

31. The polyphase power converter of claim 29, wherein each of the first plurality of circuits and each of the second plurality of circuits comprises a separate boost circuit, wherein the means for receiving a plurality of phases of the polyphase AC source is included in each boost circuit, and wherein the means includes, for each boost circuit, a separate plurality of inputs including a first input adapted to couple to a first phase of the polyphase AC source and a second input adapted to couple to second phase of the polyphase AC source.

32. The polyphase power converter of claim 31, wherein the means includes means to rectify an AC signal supplied by the polyphase AC source.

33. The polyphase power converter of claim 31, wherein the means includes switching means adapted to isolate at least one phase of the polyphase AC source from at least one of the boost circuits.

34. The polyphase power converter of claim 33, wherein the means includes a silicon controlled rectifier.

35. The polyphase power converter of claim 34, wherein the first input of each boost circuit is adapted to be coupled to the first phase of the polyphase AC source by a first silicon controlled rectifier, and wherein the second input of each boost circuit is adapted to be coupled to the second phase of the polyphase AC source by a second silicon controlled rectifier.

36. The polyphase power converter of claim 29, wherein the means includes a relay.

37. A polyphase UPS comprising:

a first input adapted to couple to a polyphase AC source;

a positive DC output;

a negative DC output;

a plurality of positive boost circuits each adapted to receive a plurality of phases of the polyphase AC source and to provide a DC signal to the positive DC output;

a plurality of negative boost circuits each adapted to receive a plurality of phases of the polyphase AC source and to provide a DC signal to the negative DC output; and

a second input adapted to be coupled to a DC power source.

38. The UPS of claim 37, wherein each of the positive boost circuits is adapted to receive a different combination of phases than others of the positive boost circuits, and wherein each of the negative boost circuits is adapted to receive a different combination of phases than others of the negative boost circuits.

39. The UPS of claim 37, further comprising a neutral output and an inverter, wherein the positive DC output, the negative DC output, and the neutral output are adapted to be coupled to the inverter.

40. The UPS of claim 37, wherein each of the boost circuits include a first input adapted to receive a rectified signal from a first phase of the polyphase AC source, and a second input adapted to receive a rectified signal from a second phase of the polyphase AC source.

41. The UPS of claim 40, wherein the first input of each boost circuit is adapted to be coupled to the first phase of the polyphase AC source by a first silicon controlled rectifier, and wherein the second input of each boost circuit is adapted to be coupled to the second phase of the polyphase AC source by a second silicon controlled rectifier, and wherein a separate first silicon controlled rectifier and a separate second silicon controlled rectifier are employed with each boost circuit.

42. The UPS of claim 37, wherein each of the positive boost circuits is adapted to receive a rectified signal from each phase of the polyphase AC source, and wherein each of the negative boost circuits is adapted to receive a rectified signal from each phase of the polyphase AC source.

43. The UPS of claim 37, further comprising a plurality of switching devices, wherein each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from one of the positive boost circuits and one of the negative boost circuits.

44. The UPS of claim 43, wherein each of the plurality of switching devices comprises a relay.

45. The UPS of claim 37, wherein the UPS includes the DC power source, and wherein the DC power source is a battery power source.