Interleaved power converter

• US 20050270806A1
• Filed: 06/04/2004
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Vitesco Technologies USA, LLC (Continental AG)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Zhu, Lizhi
• Granted Patent: US 7,295,448 B2
• Time in Patent Office: Days
• US Class Current: 363/17
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H02M 3/33576 having at least one active switching element at the secondary side of an isolation transformer

Abstract

A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

Claims

1. A power converter, comprising:

an inverter circuit comprising a first phase leg comprising a first node, a second phase leg comprising a second node, and a third phase leg comprising a third node;

a first transformer comprising a first side and a second side, the first side of the first transformer electrically coupled between the first node of the first phase leg and the second node of the second phase leg of the inverter circuit; and

a second transformer comprising a first side and a second side, the first side of the second transformer electrically coupled between the first node of the first phase leg and the third node of the third phase leg of the inverter circuit.

2. The power converter of claim 1 wherein each of the first, the second and the third phase legs comprise a respective pair of power switching elements, one of the power switching elements in the pair electrically coupled between a first rail of a power bus and the respective one of the first, the second, or the third nodes, and the other one of the power switching elements in the pair electrically coupled between a second rail of the power bus and the respective one of the first, the second, or the third nodes.

3. The power converter of claim 2, further comprising:

a current doubler rectifier electrically coupled to the second sides of the first and the second transformers.

4. The power converter of claim 3 wherein the current doubler rectifier comprises:

a first pair of switches electrically coupled in series between a first pole of the second side of the first transformer and a first pole of the second side of the second transformer, a first rectifier node formed between the switches of the first pair of switches; and

a second pair of switches electrically coupled in series between a second pole of the second side of the first transformer and a second pole of the second side of the second transformer, a second rectifier node formed between the switches of the second pair of switches, the second rectifier node electrically coupled to the first rectifier node.

5. The power converter of claim 4, further comprising:

a controller communicatingly coupled to control operation of the power switching elements of the first, the second and the third phase legs of the inverter circuit, and to control operation of the first and the second pairs of switches of the current doubler rectifier.

6. The power converter of claim 3, further comprising:

a first inductor electrically coupled in series with a first pole of the second side of the first transformer;

a second inductor electrically coupled in series with a second pole of the second side of the first transformer;

a third inductor electrically coupled in series with a first pole of the second side of the second transformer; and

a fourth inductor electrically coupled in series with a second pole of the second side of the second transformer.

7. The power converter of claim 6, further comprising:

a first capacitance comprising a first pole and a second pole, the first pole of the first capacitance electrically coupled to the first and the second inductors at a first potential node; and

a second capacitance comprising a first pole and a second pole, the second pole of the second capacitance electrically coupled to the third and the fourth inductors at a third potential node, the first pole of the second capacitance electrically coupled to the second pole of the first capacitance at a second potential node.

8. The power converter of claim 7, further comprising:

electrically coupling a single load across the first and second potential nodes in parallel with the second and the third potential nodes.

9. The power converter of claim 7, further comprising:

electrically coupling a first load across the first and the second potential nodes; and

electrically coupling a second load across the second and the third potential nodes.

10. The power converter of claim 2 wherein each of the power switching elements comprises at least one high power transistor and at least one anti-parallel diode electrically coupled across the at least one high power transistor.

11. The power converter of claim 2 wherein each of the power switching elements comprises at least one insulated gate bipolar transistor.

12. The power converter of claim 2 where in each of the power switching elements comprises at least one metal oxide semiconductor field effect transistor.

13. The power converter of claim 1 wherein the first and the second transformers are planar transformers, and the number of turns in the first side of the first and the second transformers is greater than the number of turns in the second side of the first and the second transformers.

14. The power converter of claim 1 wherein the number of turns in the first side of the first and the second transformers is less than the number of turns in the second side of the first and the second transformers.

15. A method of converting power, comprising:

inverting a direct current to produce at least three phases of alternating current;

supplying a first and a second of the three phases of alternating current to a first side of a first transformer to induce an alternating current on a second side of the first transformer;

supplying the second and a third of the three phases of alternating current to a first side of a second transformer to induce an alternating current on a second side of the second transformer;

supplying the alternating current from the second side of the first transformer to a rectifier;

supplying the alternating current from the second side of the second transformer to the rectifier; and

rectifying the first and the second alternating currents supplied to the rectifier from the second sides of the first and the second transformers, respectively, to produce a first voltage across a first potential node and a second potential node and to produce a second voltage across the second potential node and a third potential node.

16. The method of claim 15 wherein the second voltage across the second potential node and the third potential node is approximately equal to the first voltage across the first potential node and the second potential node.

17. The method of claim 15, further comprising:

inductively coupling the alternating current from the second side of the first transformer to the first and the second potential nodes; and

inductively coupling the alternating current from the second side of the second transformer to the second and the third potential nodes.

18. The method of claim 15, further comprising:

phase locking the phases of alternating current supplied to the first side of the first transformer with the phases of the alternating current supplied to the first side of the second transformer.

19. The method of claim 15 wherein supplying a first and a second of the three phases of alternating current to a first side of a first transformer comprises generating a three-level square waveform to the primary winding of the first transformer, and wherein supplying the second and a third phases of the three phases of alternating current to a first side of a second transformer comprises generating a three-level square waveform to the primary winding of the second transformer.

20. The method of claim 19 wherein generating a three-level square waveform to the primary winding of the first transformer comprises phase shift controlling a high side and a low side switch of each of a first and a second leg of an inverter circuit.

21. The method of claim 15, further comprising:

electrically coupling the first and the second voltages in parallel to a load.

22. A power converter, comprising:

a first transformer comprising a first side including at least a first pole and a second pole, and a second side including at least a first pole and a second pole;

a second transformer comprising a first side including at least a first pole and a second pole, and a second side including at least a first pole and a second pole;

means for supplying a first phase of alternating current to the first pole of the first side of the first transformer, a second phase of alternating current to the second pole of the first side of the first transformer and to the first pole of the first side of the second transformer, and a third phase of alternating current to the second pole of the first side of the second transformer; and

means for current double rectifying alternating currents supplied from the second sides of the first and the second transformers.

23. The power converter of claim 22 wherein the means for current double rectifying produces a first voltage across a first potential node and a second potential node and to produces a second voltage across the second potential node and a third potential node.

24. The power converter of claim 23 wherein an output across the first and the second potential nodes is electrically coupled in parallel with an output across the third and the second potential nodes.

25. The power converter of claim 23 wherein an output across the first and the second potential nodes is independently controllable with respect to an output across the third and the second potential nodes.

26. The power converter of claim 22, further comprising:

a number of inductors, each of the inductors electrically coupled in series with a respective one of the poles of the second sides of the first and the second transformers.

27. The power converter of claim 22, further comprising:

a first capacitor electrically coupled in parallel across the first and the second potential nodes; and

a second capacitor electrically coupled in parallel across the second and the third potential nodes.