3-phase high power UPS

• US 8,842,452 B2
• Filed: 02/22/2013
• Issued: 09/23/2014
• Est. Priority Date: 08/20/2009
• Status: Active Grant

• Current Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Original Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Inventors: Nielsen, Henning Roar
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US13/773,809
• Publication Number:
  US 20130188403A1
• Time in Patent Office: 578 Days
• Field of Search: 363/34, 363/36, 363/37, 363/65, 363/67, 363/69, 363/70, 363/71
• US Class Current: 363/37
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02J 9/063 Common neutral, e.g. AC input neutral line connected to AC output neutral line and DC middle point
• 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 5/458 using semiconductor devices only
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

According to one aspect, embodiments of the invention provide power converter circuitry including an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform, a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage; a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the plurality of DC buses during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and a second power converter coupled to the input and configured to supply power from the multiphase AC power source to at least some of the plurality of DC buses during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.

Claims

1. A method of providing AC output power from a UPS, the UPS comprising a multiphase AC input, a plurality of DC buses including a first positive DC bus, a second positive DC bus, a first negative DC bus and a second negative DC bus, power converter circuitry including a first power converter and a second power converter each coupled to the AC input and at least one of the plurality of DC buses, the method comprising acts of:

supplying power from the multiphase AC input to an input of the first power converter and providing power to the plurality of DC buses from an output of the first power converter during a first positive region of a sinusoidal waveform provided from the multiphase AC input and during a first negative region of the sinusoidal waveform;

supplying power from the multiphase AC input to an input of the second power converter and providing power to at least some of the plurality of DC buses from an output of the second power converter during a second positive region of the sinusoidal waveform and during a second negative region of the sinusoidal waveform; and

converting power supplied from the plurality of DC buses to AC output power provided at an AC output of the UPS.

2. The method of claim 1, further comprising an act of providing power to the plurality of DC buses from the output of the first power converter for phase angles of the sinusoidal waveform in a region about a phase angle of a peak positive amplitude of the sinusoidal waveform and in a region about a phase angle of a peak negative amplitude of the sinusoidal waveform.

3. The method of claim 2, further comprising an act of providing power to at least some of the plurality of DC buses from the output of the second power converter for phase angles of the sinusoidal waveform in a region about a zero crossing of the sinusoidal waveform.

4. The method of claim 1, further comprising an act of operating the first power converter and the second power converter such that a sum of current drawn at the AC input provides a substantially sinusoidal current at all phase angles of the sinusoidal waveform.

5. The method of claim 1, further comprising acts of:

generating a waveform representative of a sinusoidal input current of the UPS;

generating a first reference waveform concerning a magnitude of current drawn by the second power converter for phase angles in a vicinity of a zero crossing of the waveform representative of the sinusoidal input current;

generating a first current reference signal by combining the first reference waveform and the waveform representative of the sinusoidal input current, wherein the first current reference signal is employed in controlling an operation of the second power converter; and

generating a second current reference signal by combining the first current reference signal and the waveform representative of the sinusoidal input current to control an operation of the first power converter.

6. The method of claim 1, wherein the first positive region and the second positive region include different regions of the sinusoidal waveform, and wherein the first negative region and the second negative region include different regions of the sinusoidal waveform.

7. The method of claim 1, wherein the first power converter comprises a positive boost circuit and a negative boost circuit, and wherein the method further comprises acts of:

drawing, with the positive boost circuit, current during the first positive region of the sinusoidal waveform for each phase of the multiphase AC power signal; and

drawing, with the negative boost circuit, current during the first negative region of the sinusoidal waveform for each phase of the multiphase AC power signal.

8. The method of claim 7, wherein the second power converter comprises a positive boost circuit and a negative boost circuit and wherein the method further comprises acts of:

drawing, with the positive boost circuit of the second power converter, current during the second positive region for each phase of the multiphase AC power signal; and

drawing, with the negative boost circuit of the second power converter, current during the second negative region for each phase of the multiphase AC power signal.

9. The method of claim 3, wherein the act of providing power to at least some of the plurality of DC buses from the output of the second power converter includes providing power to at least some of the plurality of DC buses from the output of the second power converter for phase angles of the sinusoidal waveform in a range of ±

30 degrees about each zero crossing of the sinusoidal waveform.

10. The method of claim 1, further comprising an act of rectifying the power provided from the multiphase AC input to the input of the first power converter.

11. The method of claim 1, wherein the UPS further comprises a DC power source, and wherein the method further comprises acts of:

determining that the power supplied by the multiphase input to the input of the first power converter is not at a desired level; and

in response to a determination that the power supplied by the multiphase input to the input of the first power converter is not at a desired level, supplying power from the DC power source to the input of the first power converter and providing power to the plurality of DC buses from the output of the first power converter.

12. The method of claim 11, further comprising an act of supplying power from the plurality of DC buses to the DC power source to charge the DC power source.

13. The method of claim 11, further comprising an act of supplying a majority of the power delivered to the AC output from the DC power source.

14. The method of claim 11, further comprising an act of supplying a majority of the power delivered to the AC output from the output of the second power converter.

15. Power converter circuitry comprising:

an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source providing output power having a sinusoidal waveform;

a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage;

a first power converter coupled to the input and the plurality of DC buses;

a second power converter coupled to the input and the plurality of DC buses; and

means for performing load sharing between the first power converter and the second power converter.

16. The power converter circuitry of claim 15, further comprising:

a DC power source coupled to the first power converter; and

means for performing load sharing between the DC power source, the first power converter and the second power converter.

17. The power converter circuitry of claim 15, further comprising a rectifier coupled to the input, the rectifier including an output coupled to an input of the first power converter.

18. The power converter circuitry of claim 17, further comprising a first switch configured to electrically isolate the rectifier from each phase of the multiphase AC power source, and a second switch configured to electrically isolate the second power converter from each phase of the multiphase AC power source.

19. The power circuitry of claim 15, wherein the first power converter comprises a positive boost circuit coupled between the input and the plurality of DC buses and a negative boost circuit coupled between the input and the plurality of DC buses, and

wherein the second power converter comprises a positive boost circuit coupled between the input and the plurality of DC buses and a negative boost circuit coupled between the input and the plurality of DC buses.

20. Power converter circuitry comprising:

an input configured to be coupled to a multiphase AC power source providing AC power having a sinusoidal waveform;

a DC bus;

a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the DC bus during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and

a second power converter coupled to the input and configured to supply power from the multiphase AC power source to the DC bus during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.