Power supply providing backup AC voltage and method of operation thereof

• US 6,198,177 B1
• Filed: 01/07/2000
• Issued: 03/06/2001
• Est. Priority Date: 01/07/2000
• Status: Expired due to Fees

• Current Assignee: Lineage Power Corporation (GE Aerospace)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Thottuvelil, Vijayan J., Mao, Hengchun
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): DeBeradinis, Robert L
• Application Number:
  US09/479,514
• Time in Patent Office: 424 Days
• Field of Search: 307/66, 307/64
• US Class Current: 307/66
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02J 9/067 using multi-primary transformers, e.g. transformer having one primary for each AC energy source and a secondary for the loads
• 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 3/33584 Bidirectional converters

Abstract

A power supply that provides a source of backup AC voltage and a method of operating thereof. In one embodiment, the power supply includes a transformer having main power and backup power windings and a secondary winding. The power supply also includes multiple stages, namely, (1) a primary power stage coupled to the main power winding, (2) a backup power stage coupled to the backup power winding and having a backup battery, one of the primary and backup power stages acting as a current fed source and (3) an AC power stage, coupled to the secondary winding, that provides a source of AC voltage. The power supply is operable in a normal mode of operation in which the primary power stage supplies power to the secondary winding and further supplies power to the backup power winding to allow the backup power stage to charge the backup battery. The power supply is also operable in a backup mode of operation in which the backup power stage transfers power from the backup battery to the secondary winding via the backup power winding.

Claims

1. A power supply, comprising:

a transformer having a main power winding with a first leakage inductance, a backup power winding with a second leakage inductance, and a secondary winding;

a primary power stage coupled to said main power winding;

a backup power stage coupled to said backup power winding and having a backup battery, one of said primary and backup power stages acting as a current fed source and including an inductor with an inductance greater than one of said first or second leakage inductances to which said current fed source is coupled; and

an AC power stage, coupled to said secondary winding, that provides a source of AC voltage, said power supply operable in;

a normal mode of operation in which said primary power stage supplies power to said secondary winding and further supplies power to said backup power winding to allow said backup power stage to charge said backup battery, and

a backup mode of operation in which said backup power stage transfers power from said backup battery to said secondary winding via said backup power winding.

2. The power supply as recited in claim 1 wherein said transformer has a second secondary winding coupled to a DC power stage that provides a source of DC voltage.

3. The power supply as recited in claim 1 wherein said primary power stage comprises a primary switching network.

4. The power supply as recited in claim 1 wherein said backup power stage comprises a battery charger/inverter.

5. The power supply as recited in claim 2 wherein said DC power stage comprises a rectifier.

6. The power supply as recited in claim 2 wherein said DC power stage comprises a DC output switching network.

7. The power supply as recited in claim 1 wherein said AC power stage comprises an AC output switching network.

8. The power supply as recited in claim 1 wherein said AC power stage supplies an output frequency in a range of about 50 to 60 hertz.

9. The power supply as recited in claim 1 wherein said primary power stage comprises at least one input capacitor.

10. A method of operating a power supply, comprising:

initiating a normal mode of operation in which a primary power stage of said power supply supplies power to a secondary winding of a transformer coupled to said primary power stage via a main power winding, having a first leakage inductance, of said transformer and further supplies power to a backup power winding, having a second leakage inductance, of said transformer to allow a backup power stage coupled to said backup power winding to charge a backup battery, one of said primary and backup power stages acting as a current fed source and including an inductor with an inductance greater than one of said first or second leakage inductances to which said current fed source is coupled, said secondary winding being coupled to an AC power stage; and

entering a backup mode of operation in which said backup power stage transfers power from said backup battery to said secondary winding via said backup power winding.

11. The method as recited in claim 10 wherein said power supply supplies power to a second secondary winding of said transformer coupled to a DC power stage that provides a source of DC voltage.

12. The method as recited in claim 11 wherein said DC power stage comprises a rectifier.

13. The method as recited in claim 11 wherein said DC power stage comprises a DC output switching network.

14. The method as recited in claim 10 wherein said primary power stage comprises a primary switching network.

15. The method as recited in claim 10 wherein said backup power stage comprises a battery charger/inverter.

16. The method as recited in claim 10 wherein said AC power stage comprises an AC output switching network.

17. The method as recited in claim 10 wherein said AC power stage supplies an output frequency in a range of about 50 to 60 hertz.

18. The method as recited in claim 10 wherein said primary power stage comprises at least one input capacitor.