Resonant power factor correction converter

• US 8,693,213 B2
• Filed: 05/21/2008
• Issued: 04/08/2014
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: MyPAQ Holdings Ltd. (Transpacific IP Group Limited)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Jungreis, Aaron, Garrity, Paul
• Primary Examiner(s): Zhang, Jue
• Application Number:
  US12/154,321
• Publication Number:
  US 20090290385A1
• Time in Patent Office: 2,148 Days
• Field of Search: 363/16, 363/17, 363/132, 363/21.02, 363/21.03, 323/266, 323/272
• US Class Current: 363/17
• 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 1/4241 using a resonant converter
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An AC-to-DC power converter configured to provide power factor correction and a single isolated low-voltage output. The power converter includes a single-stage resonant power converter including an isolation transformer, a resonant tank, a rectifier, and a bulk storage capacitor coupled to an output of the isolation transformer. In typical applications, at least one non-isolated power converter is coupled to the output of the single-stage isolated power factor correction converter.

Claims

1. A power converter comprising:

a. a single-stage power-factor-correction resonant converter configured to receive an input voltage, wherein the single-stage power-factor-correction resonant converter includes an isolation transformer and a resonant tank, the resonant tank comprising a variable inductor coupled to a primary of the isolation transformer;

b. a rectifier coupled to an output of the isolation transformer; and

c. a bulk capacitor coupled to an output of the rectifier, wherein a voltage across the bulk capacitor is a direct-current output voltage of the single-stage power-factor-correction resonant converter, thereby providing a single voltage output bus for the single-stage power-factor-correction resonant converter, and the variable inductor is configured to tune a resonant frequency of the resonant tank in response to the direct-current output voltage thereby regulating the direct-current output voltage.

2. The power converter of claim 1 further comprising one or more power converters coupled to the bulk capacitor.

3. The power converter of claim 2 wherein each power converter coupled to the bulk capacitor is non-isolated.

4. The power converter of claim 2 wherein each power converter coupled to the bulk capacitor is configured to independently control its output voltage.

5. The power converter of claim 2 wherein each power converter is one of a group consisting of a non-isolated buck-type converter, a non-isolated boost-type converter, and a flyback converter.

6. The power converter of claim 1 further comprising a tap switch coupled between the isolation transformer and the bulk capacitor, wherein the tap switch is configured to increase and decrease a functional turns ratio of the isolation transformer.

7. The power converter of claim 6 wherein the isolation transformer includes a number of secondary windings, and the tap switch couples a portion of the number of secondary windings to the bulk capacitor.

8. The power converter of claim 1 wherein the single-stage power-factor-correction resonant converter includes a switchable bridge configured to operate as a half-bridge converter under high-line voltage conditions and to operate as a full-bridge converter under low-line voltage conditions.

9. The power converter of claim 1 further comprising:

a. an electromagnetic interference filter; and

b. a bridge rectifier coupled between an output of the electromagnetic filter and an input of the single-stage power-factor-correction resonant converter.

10. The power converter of claim 9 wherein the bridge rectifier comprises a plurality of diodes.

11. The power converter of claim 9 wherein the bridge rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

12. The power converter of claim 1 wherein the single-stage power-factor-correction resonant converter is configured as one of the group consisting of a series resonant circuit, a parallel resonant circuit, an LLC resonant circuit, and a series-parallel resonant circuit.

13. The power converter of claim 1 wherein the single-stage power-factor-correction resonant converter comprises one of the group consisting of a half-bridge resonant converter, a full-bridge resonant converter, a push-pull resonant converter, and a forward converter.

14. The power converter of claim 1 wherein the rectifier comprises a plurality of diodes.

15. The power converter of claim 1 wherein the rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

16. The power converter of claim 1 wherein the isolation transformer is configured as a step-down transformer.

17. The power converter of claim 1 wherein the input voltage is a rectified DC voltage, and each output voltage is a DC voltage.

18. The power converter of claim 1 wherein the single-stage power-factor-correction resonant converter is configured to operate using soft-switching.

19. The power converter of claim 1 wherein a turns ratio of the isolation transformer is configured to be adapted to match a specific bobbin used in the manufacturing of the isolation transformer.

20. The power converter of claim 1 further comprising a control module configured to regulate the direct-current output voltage and control a value of the at least one variable storage element.

21. An AC-to-DC power converter comprising:

a. a bridge rectifier configured to receive an input AC voltage, wherein the bridge rectifier is configured to output a DC voltage corresponding to the input AC voltage;

b. a single-stage power-factor-correction resonant converter coupled to the bridge rectifier to receive the DC voltage, wherein the single-stage power-factor-correction resonant converter includes an isolation transformer, a resonant tank, the resonant tank having at least one variable inductor coupled to a primary of the isolation transformer, and a switchable bridge configured to operate as a half-bridge converter under high-line voltage conditions and to operate as a full-bridge converter under low-line voltage conditions;

c. a rectifier coupled to an output of the isolation transformer; and

d. a bulk capacitor coupled to an output of the rectifier, wherein a voltage across the bulk capacitor is an output DC voltage of the AC-to-DC power converter, and the variable inductor is configured to tune a resonant frequency of the resonant tank in response to the output DC voltage thereby regulating the output DC voltage, further wherein the output DC voltage is regulated to substantially the same voltage level whether the switchable bridge is operating as the half-bridge under high-line voltage conditions or as the full-bridge converter under low-line voltage conditions.

22. The power converter of claim 21 further comprising one or more power converters coupled to the bulk capacitor.

23. The power converter of claim 22 wherein each power converter coupled to the bulk capacitor is non-isolated.

24. The power converter of claim 22 wherein each power converter coupled to the bulk capacitor is configured to independently control its output voltage.

25. The power converter of claim 22 wherein each power converter is one of a group consisting of a non-isolated buck-type converter, a non-isolated boost-type converter, and a flyback converter.

26. The power converter of claim 21 further comprising a tap switch coupled between the isolation transformer and the bulk capacitor, wherein the tap switch is configured to increase and decrease a functional turns ratio of the isolation transformer.

27. The power converter of claim 26 wherein the isolation transformer includes a number of secondary windings, and the tap switch couples a portion of the number of secondary windings to the bulk capacitor.

28. The power converter of claim 21 further comprises an electromagnetic interference filter coupled to an input of the bridge rectifier.

29. The power converter of claim 21 wherein the bridge rectifier comprises a plurality of diodes.

30. The power converter of claim 21 wherein the bridge rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

31. The power converter of claim 21 wherein the single-stage power-factor-correction resonant converter is configured as one of the group consisting of a series resonant circuit, a parallel resonant circuit, an LLC resonant circuit, and a series-parallel resonant circuit.

32. The power converter of claim 21 wherein the single-stage power-factor-correction resonant converter comprises one of the group consisting of a half-bridge resonant converter, a full-bridge resonant converter, a push-pull resonant converter, and a forward converter.

33. The power converter of claim 21 wherein the rectifier comprises a plurality of diodes.

34. The power converter of claim 21 wherein the rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

35. The power converter of claim 21 wherein the isolation transformer is configured as a step-down transformer.

36. The power converter of claim 21 wherein the single-stage power-factor-correction resonant converter is configured to operate using soft-switching.

37. The power converter of claim 21 wherein a turns ratio of the isolation transformer is configured to be adapted to match a specific bobbin used in the manufacturing of the isolation transformer.

38. The power converter of claim 21 further comprising a control module configured to regulate the direct-current output voltage and control a value of the at least one variable energy storage element.

39. An AC-to-DC power converter comprising:

a. a bridge rectifier configured to receive an input AC voltage, wherein the bridge rectifier is configured to output a DC voltage corresponding to the input AC voltage;

b. a single-stage power-factor-correction resonant converter coupled to the bridge rectifier to receive the DC voltage, wherein the single-stage power-factor-correction resonant converter includes an isolation transformer and a resonant tank, the resonant tank having at least one variable inductor coupled to a primary of the isolation transformer;

c. a rectifier coupled to an output of the isolation transformer;

d. a tap switch coupled to an output of the rectifier, wherein the tap switch is configured to increase and decrease a functional turns ratio of the isolation transformer thereby reducing a peak current through the variable inductor; and

e. a bulk capacitor coupled to the tap switch and to the output of the rectifier, wherein a voltage across the bulk capacitor is an output DC voltage of the AC-to-DC power converter, and the variable inductor is configured to tune a resonant frequency of the resonant tank in response to the output DC voltage thereby regulating the output DC voltage.

40. The power converter of claim 39 wherein the single-stage power-factor-correction resonant converter further comprises a switchable bridge configured to operate as a half-bridge converter under high-line voltage conditions and to operate as a full-bridge converter under low-line voltage conditions.

41. The power converter of claim 39 further comprising one or more power converters coupled to the bulk capacitor.

42. The power converter of claim 41 wherein each power converter coupled to the bulk capacitor is non-isolated.

43. The power converter of claim 41 wherein each power converter coupled to the bulk capacitor is configured to independently control its output voltage.

44. The power converter of claim 41 wherein each power converter is one of a group consisting of a non-isolated buck-type converter, a non-isolated boost-type converter, and a flyback converter.

45. The power converter of claim 39 wherein the isolation transformer includes a number of secondary windings, and the tap switch couples a portion of the number of secondary windings to the bulk capacitor.

46. The power converter of claim 39 further comprising an electromagnetic interference filter coupled to an input of the bridge rectifier.

47. The power converter of claim 39 wherein the bridge rectifier comprises a plurality of diodes.

48. The power converter of claim 39 wherein the bridge rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

49. The power converter of claim 39 wherein the single-stage power-factor-correction resonant converter is configured as one of the group consisting of a series resonant circuit, a parallel resonant circuit, an LLC resonant circuit, and a series-parallel resonant circuit.

50. The power converter of claim 39 wherein the single-stage power-factor-correction resonant converter comprises one of the group consisting of a half-bridge resonant converter, a full-bridge resonant converter, a push-pull resonant converter, and a forward converter.

51. The power converter of claim 39 wherein the rectifier comprises a plurality of diodes.

52. The power converter of claim 39 wherein the rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

53. The power converter of claim 39 wherein the isolation transformer is configured as a step-down transformer.

54. The power converter of claim 39 wherein the single-stage power-factor-correction resonant converter and each of the non-isolated power converters are configured to operate using soft-switching.

55. The power converter of claim 39 wherein a turns ratio of the isolation transformer is configured to be adapted to match a specific bobbin used in the manufacturing of the isolation transformer.

56. The power converter of claim 39 further comprising a control module configured to regulate the direct-current output voltage and control a value of the at least one variable energy storage element.

57. An AC-to-DC power converter comprising:

a. a bridge rectifier configured to receive an input AC voltage, wherein the bridge rectifier is configured to output a DC voltage corresponding to the input AC voltage;

b. a single-stage power-factor-correction resonant converter coupled to the bridge rectifier to receive the DC voltage, wherein the single-stage power-factor-correction resonant converter includes an isolation transformer, a resonant tank, the resonant tank having at least one variable inductor coupled to a primary of the isolation transformer, and a switchable bridge configured to operate as a half-bridge converter under high-line voltage conditions and to operate as a full-bridge converter under low-line voltage conditions;

c. a rectifier coupled to an output of the isolation transformer;

d. a tap switch coupled to an output of the rectifier, wherein the tap switch is configured to increase and decrease a functional turns ratio of the isolation transformer; and

e. a bulk capacitor coupled to the tap switch and to the output of the rectifier, wherein a voltage across the bulk capacitor is an output DC voltage of the AC-to-DC power converter and the variable inductor is configured to tune a resonant frequency of the resonant tank in response to the output DC voltage thereby regulating the output DC voltage, further wherein the output DC voltage is regulated to substantially the same voltage level whether the switchable bridge is operating as the half-bridge under high-line voltage conditions or as the full-bridge converter under low-line voltage conditions.

58. The power converter of claim 57 further comprising an electromagnetic interference filter coupled to an input of the bridge rectifier.

59. The power converter of claim 57 further comprising one or more power converters coupled to the bulk capacitor.

60. The power converter of claim 59 wherein each power converter coupled to the bulk capacitor is non-isolated.

61. The power converter of claim 59 wherein each power converter coupled to the bulk capacitor is configured to independently control its output voltage.

62. The power converter of claim 59 wherein each power converter is one of a group consisting of a non-isolated buck-type converter, a non-isolated boost-type converter, and a flyback converter.

63. The power converter of claim 57 wherein the isolation transformer includes a number of secondary windings, and the tap switch couples a portion of the number of secondary windings to the bulk capacitor.

64. The power converter of claim 57 wherein the bridge rectifier comprises a plurality of diodes.

65. The power converter of claim 57 wherein the bridge rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

66. The power converter of claim 57 wherein the single-stage power-factor-correction resonant converter is configured as one of the group consisting of a series resonant circuit, a parallel resonant circuit, an LLC resonant circuit, and a series-parallel resonant circuit.

67. The power converter of claim 57 wherein the rectifier comprises a plurality of diodes.

68. The power converter of claim 57 wherein the rectifier comprises a plurality of metal-oxide-semiconductor field-effect transistors.

69. The power converter of claim 57 wherein the isolation transformer is configured as a step-down transformer.

70. The power converter of claim 57 wherein the single-stage power-factor-correction resonant converter and each of the non-isolated power converters are configured to operate using soft-switching.

71. The power converter of claim 57 wherein a turns ratio of the isolation transformer is configured to be adapted to match a specific bobbin used in the manufacturing of the isolation transformer.

72. The power converter of claim 57 further comprising a control module configured to regulate the direct-current output voltage and control a value of the at least one variable energy storage element.