Multiphase DC to DC converter

• US 20070086224A1
• Filed: 10/13/2006
• Published: 04/19/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Astec International Limited (Emerson Electric Company)
• Original Assignee: Astec International Limited (Emerson Electric Company)
• Inventors: Beltran, Israel, Sigamani, James, Phadke, Vijay
• Granted Patent: US 7,596,007 B2
• Time in Patent Office: Days
• US Class Current: 363/65
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10

Abstract

A multiphase DC to DC converter includes an input, an output, at least first and second converters, an inductor, an output capacitor, and a drive circuit. The drive circuit is configured for switching the first and second converters with a predetermined phase shift therebetween. The output capacitor is operatively coupled between the first and second converters and the output. The inductor can be placed either at the input side or the output side. When placed at the input side, the inductor is operatively coupled between an input capacitor and the first and second converters. When placed at the output side, the inductor is operatively coupled between the first and second converters and the output capacitor. The multiphase DC to DC converter is capable of achieving lossless switching transitions and negligible ripple current in the output capacitor.

Claims

1. A multiphase DC to DC converter comprising an input, an output, at least first and second converters, an inductor, an output capacitor, and a drive circuit, the drive circuit configured for switching the first and second converters with a predetermined phase shift therebetween, the inductor operatively coupled to the first and second converters, and the output capacitor operatively coupled between the inductor and the output.

2. The multiphase DC to DC converter of claim 1 wherein the drive circuit is configured to turn on the second converter when the inductor is being charged by the first converter to thereby achieve substantially zero current transition during turn on of the second converter.

3. The multiphase DC to DC converter of claim 2 wherein at least one of the converters includes a transformer having a primary winding coupled to at least one primary switch and a secondary winding coupled to at least one synchronous rectifier, and wherein the drive circuit is configured to turn on the synchronous rectifier shortly after turning on the primary switch.

4. The multiphase DC to DC converter of claim 3 wherein the drive circuit is further configured to turn off the synchronous rectifier shortly before turning off the primary switch.

5. The multiphase DC to DC converter of claim 2 wherein the first and second converters include first and second rectification circuits, respectively.

6. The multiphase DC to DC converter of claim 5 wherein the first and second rectification circuits comprise diode rectifiers.

7. The multiphase DC to DC converter of claim 5 wherein the first and second rectification circuits comprise synchronous rectifiers.

8. The multiphase DC to DC converter of claim 2 wherein at least one of the converters includes a transformer having a primary winding coupled to first and second switches, and wherein the drive circuit is configured to provide substantially complementary control signals to said first and second switches.

9. The multiphase DC to DC converter of claim 1 wherein the predetermined phase shift is about 90 degrees.

10. The multiphase DC to DC converter of claim 1 wherein the first and second converters employ the same topology.

11. The multiphase DC to DC converter of claim 10 wherein the first and second converters are half bridge converters.

12. The multiphase DC to DC converter of claim 11 wherein the drive circuit is configured to switch the first and second converters each at a duty cycle of approximately fifty percent (50%).

13. The multiphase DC to DC converter of claim 10 wherein the first and second converters are full bridge converters.

14. The multiphase DC to DC converter of claim 1 wherein at least the first converter includes a center-tapped full wave rectifier.

15. The multiphase DC to DC converter of claim 1 wherein at least the first converter includes a bridge type rectifier.

16. The multiphase DC to DC converter of claim 1 wherein the drive circuit is configured for switching the first and second converters at a fixed frequency and with said predetermined phase shift therebetween.

17. A multiphase DC to DC converter comprising an input, an output, at least first and second converters, an inductor, an output capacitor, and a drive circuit, the drive circuit configured for switching the first and second converters with a predetermined phase shift therebetween, the output capacitor operatively coupled between the first and second converters and the output, and the inductor operatively coupled between (a) the first and second converters, and (b) said input or said output capacitor.

18. The multiphase DC to DC converter of claim 17 wherein the inductor is operatively coupled between (a) the first and second converters, and (b) said input.

19. The multiphase DC to DC converter of claim 18 wherein at least one of the converters includes a transformer having a primary winding coupled to first and second switches, and wherein the drive circuit is configured to provide substantially complementary control signals to said first and second switches.

20. The multiphase DC to DC converter of claim 18 wherein the predetermined phase shift is about 90 degrees.

21. The multiphase DC to DC converter of claim 18 wherein the first and second converters employ the same topology.

22. The multiphase DC to DC converter of claim 21 wherein the first and second converters are half bridge converters.

23. The multiphase DC to DC converter of claim 22 wherein the drive circuit is configured to switch the first and second converters each at a duty cycle of approximately fifty percent (50%).

24. The multiphase DC to DC converter of claim 18 wherein at least the first converter includes a center-tapped full wave rectifier.

25. The multiphase DC to DC converter of claim 18 wherein at least the first converter includes a bridge type rectifier.

26. The multiphase DC to DC converter of claim 17 wherein the inductor is operatively coupled between (a) the first and second converters, and (b) said output capacitor.

27. A multiphase DC to DC converter comprising an input, an output, an output capacitor, at least first and second converters, and an inductor operatively coupled to the first and second converters, the inductor providing substantially zero ripple current in the output capacitor when the second converter is operated about ninety degrees out of phase with respect to the first converter.

28. The multiphase DC to DC converter of claim 27 wherein the first and second converters are each operated at a duty cycle of approximately fifty percent (50%).

29. The multiphase DC to DC converter of claim 28 wherein the first and second converters are the only converters in said multiphase DC to DC converter.

30. The multiphase DC to DC converter of claim 27 wherein the inductor is operatively coupled between the first and second converters and the input.

31. The multiphase DC to DC converter of claim 27 wherein the inductor is operatively coupled between the first and second converters and the output capacitor.

32. The multiphase DC to DC converter of claim 27 further comprising a drive circuit for switching the first and second converters at a fixed frequency.

33. The multiphase DC to DC converter of claim 27 further comprising at least third and fourth converters.

34. The multiphase DC to DC converter of claim 28 wherein the first, second, third and fourth converters are each operated at a duty cycle of approximately fifty percent (50%) and with a phase difference of approximately forty-five degrees.