Single phase redundant power supply systems for reducing phase current imbalances

• US 9,891,679 B2
• Filed: 12/22/2011
• Issued: 02/13/2018
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Astec International Limited (Emerson Electric Company)
• Original Assignee: Astec International Limited (Emerson Electric Company)
• Inventors: Phadke, Vijay Gangadhar, Myers, Robert Lee
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Dhillon, Jagdeep
• Application Number:
  US13/334,809
• Publication Number:
  US 20130163297A1
• Time in Patent Office: 2,245 Days
• Field of Search: 307 43, 307 14, 307115, 307 62, 307 80, 307151, 726 6, 726 18, 726 30, 700293, 700297, 363 89, 363126, 323371
• CPC Class Codes: G05F 1/70 Regulating power factor; Regulating reactive current or power
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02J 2310/16 The load or loads being an Information and Communication Technology [ICT] facility
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/26 Arrangements for eliminating or reducing asymmetry in polyphase networks
• CPC Class Codes: Y02E 40/50 Arrangements for eliminating or reducing asymmetry in polyphase networks

Abstract

A single phase redundant power supply system may include a first power supply having an input coupled to a first phase voltage in a polyphase power distribution system and an output coupled to a load for supplying an amount of DC power to the load, and a second power supply having an input for coupling to a second phase voltage in the polyphase power distribution system and an output coupled to the load for supplying an amount of DC power to the load. At least the first power supply is configured to reduce phase current imbalances in the polyphase power distribution system by adjusting the amount of DC power supplied to the load by the first power supply and the amount of DC power supplied to the load by the second power supply.

Claims

1. A system comprising:

a first AC/DC power supply having an input coupled to a first phase voltage in a polyphase power distribution system, and an output coupled to a load for supplying an amount of DC power to the load;

a second AC/DC power supply having an input for coupling to a second phase voltage in the polyphase power distribution system, and an output coupled to the load for supplying an amount of DC power to the load; and

a controller for controlling one of the first AC/DC power supply and the second AC/DC power supply;

wherein the output of the first AC/DC power supply is coupled in parallel with the output of the second AC/DC power supply; and

wherein the controller is configured to reduce phase current imbalances in the polyphase power distribution system by adjusting the amount of DC power supplied to the load by the first AC/DC power supply and the amount of DC power supplied to the load by the second AC/DC power supply so the amount of DC power supplied to the load by the first AC/DC power supply is different than the amount of DC power supplied to the load by the second AC/DC power supply when the number of power supplies per phase of the polyphase power distribution system is the same.

2. The system of claim 1 wherein the controller is configured to adjust the amount of DC power supplied to the load by the first AC/DC power supply in response to a voltage level of the first phase voltage.

3. The system of claim 2 wherein the controller is configured to adjust the amount of DC power supplied to the load by the first AC/DC power supply in response to a difference between the first phase voltage and a nominal phase voltage.

4. The system of claim 2 further comprising a phase current controller configured to monitor a plurality of phase currents in the polyphase power distribution system, and wherein the controller for controlling one of the first AC/DC power supply and the second AC/DC power supply is configured to adjust the amount of DC power supplied to the load by the first AC/DC power supply in response to one or more signals from the phase current controller.

5. The system of claim 4 wherein the controller for controlling one of the first AC/DC power supply and the second AC/DC power supply is selectively configurable to adjust the amount of DC power supplied to the load by the first AC/DC power supply in response to the voltage level of the first phase voltage, or the one or more signals from the phase current controller.

6. The system of claim 1 further comprising a phase current controller configured to monitor a plurality of phase currents in the polyphase power distribution system, wherein the controller for controlling one of the first AC/DC power supply and the second AC/DC power supply is configured to adjust the amount of DC power supplied to the load by the first AC/DC power supply in response to one or more signals from the phase current controller.

7. The system of claim 6 wherein the phase current controller is external to the first AC/DC power supply and the second AC/DC power supply.

8. The system of claim 6 wherein the phase current controller is configured to provide the one or more signals directly to the first AC/DC power supply via a wired or wireless communication link.

9. The system of claim 6 wherein the first and second power supplies are hosted by the load, and the phase current controller is configured to provide the one or more signals to the load.

10. The system of claim 9 wherein the load is a computer server.

11. The system of claim 1 wherein the first AC/DC power supply and the second AC/DC power supply are each configured to supply DC current to the load at a substantially constant output voltage.

12. The system of claim 11 wherein the controller includes an output current sharing function for the first AC/DC power supply and is configured to adjust the amount of DC current supplied to the load by the first AC/DC power supply by adjusting its output current sharing behavior.

13. The system of claim 12 wherein the controller includes an output current sharing function for the second AC/DC power supply.

14. The system of claim 12 wherein the controller is configured to generate a current sharing parameter according to its output current sharing function, and to adjust the generated current sharing parameter to reduce phase current imbalances in the polyphase power distribution system.

15. The system of claim 14 wherein the current sharing parameter is a droop voltage.

16. The system of claim 14 wherein the current sharing parameter is a communication signal representing the amount of DC current supplied to the load by the first AC/DC power supply.

17. The system of claim 14 wherein the controller is configured to adjust the generated current sharing parameter based on a voltage level of the first phase voltage.

18. The system of claim 14 further comprising a phase current controller configured to monitor a plurality of phase currents in the polyphase power distribution system, wherein the controller for controlling one of the first AC/DC power supply and the second AC/DC power supply is configured to adjust the generated current sharing parameter in response to one or more signals from the phase current controller.

19. The system of claim 1 wherein the polyphase power distribution system is a three phase power distribution system.

20. The system of claim 19 further comprising a third AC/DC power supply having an input coupled to a third phase voltage in the three phase power distribution system, and an output coupled in parallel with the output of the first AC/DC power supply and the output of the second AC/DC power supply.

21. The system of claim 1 wherein the controller is configured to reduce imbalances between a first phase current provided to the input of the first AC/DC power supply and a second phase current provided to the input of the second AC/DC power supply.

22. The system of claim 1 wherein the controller is configured to adjust the amount of DC power supplied to the load by the first AC/DC power supply and the amount of DC power supplied to the load by the second AC/DC power supply without substantially changing an overall amount of DC power supplied to the load.

23. The system of claim 22 wherein the controller is configured to adjust the DC power supplied to the load by the first AC/DC power supply and the DC power supplied to the load by the second AC/DC power supply in substantially equal but opposite amounts.

32. The system of claim 1 wherein the controller is internal to one of the first AC/DC power supply and the secod AC/DC power supply.

24. A system comprising:

a first plurality of AC/DC power supplies fed by a first phase voltage in a three phase power distribution system;

a second plurality of AC/DC power supplies fed by a second phase voltage in the three phase power distribution system;

a third plurality of AC/DC power supplies fed by a third phase voltage in the three phase power distribution system;

each power supply having an output coupled in parallel with at least one other power supply fed by a different phase voltage; and

a controller configured to generate control signals for adjusting a DC output of one or more of the power supplies to reduce phase current imbalances in the three phase power distribution system so a DC output of at least one power supply of the power supplies is different than a DC output of at least another power supply of the power supplies when the number of power supplies per phase of the three phase power distribution system is the same.

25. The system of claim 24 wherein each power supply includes an output current sharing function and is configured to adjust its output current sharing behavior in response to one or more signals from the controller.

26. The system of claim 25 wherein the controller is configured to control the first plurality of power supplies as a first group, the second plurality of power supplies as a second group, and the third plurality of power supplies as a third group.

27. The system of claim 26 wherein the first, second and third plurality of AC/DC power supplies each have outputs coupled to a common DC bus.

28. The system of claim 27, further comprising a plurality of computer servers coupled to the common DC bus.

29. The system of claim 26 wherein the controller is an intermediate controller, the system further comprising a phase current controller configured to monitor phase currents in the three phase power distribution system and generate one or more control signals to reduce imbalances among the monitored phase currents.

30. The system of claim 26, wherein the controller is a phase current controller configured to monitor phase currents and reduce phase current imbalances in the three phase power distribution system.

31. The system of claim 30, further comprising a remote distribution unit for supplying the first, second and third phase voltages to the first, second and third plurality of power supplies, wherein the phase current controller is configured to monitor phase currents input to the remote distribution unit.