TWO STAGE RESONANT CONVERTER

• US 20110261590A1
• Filed: 04/22/2010
• Published: 10/27/2011
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Flextronics Limited (Flex, Ltd.)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Liu, Martin
• Granted Patent: US 8,964,413 B2
• Time in Patent Office: Days
• US Class Current: 363/17
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 3/3378 in a push-pull configuration of the parallel type H02M3/3374 takes precedence
• 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
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A resonant converter comprising: a controllable current source; a resonant tank circuit coupled to the current source; and an isolated buck-type converter coupled to the resonant tank circuit, the isolated buck-type converter having an output, wherein the resonant tank circuit enables switches in the isolated buck-type converter to switch under soft-switching conditions. In some embodiments, the controllable current source is a switch-mode-type current source. In some embodiments, the isolated buck-type converter comprises a half-bridge converter. In some embodiments, the isolated buck-type converter comprises a full-bridge converter. In some embodiments, the isolated buck-type converter comprises a push-pull converter.

Claims

1. A resonant converter comprising:

a controllable current source;

a resonant tank circuit coupled to the current source; and

an isolated buck-type converter coupled to the resonant tank circuit, the isolated buck-type converter having an output,

wherein the resonant tank circuit enables switches in the isolated buck-type converter to switch under soft-switching conditions.

2. The resonant converter of claim 1, wherein the controllable current source is a switch-mode-type current source.

3. The resonant converter of claim 1, further comprising a power factor correction (PFC) boost converter coupled to an input of the controllable current source, wherein the PFC boost converter is configured to provide a voltage to the input of the controllable current source.

4. The resonant converter of claim 3, wherein:

the PFC boost converter is configured to provide a DC input voltage to the input of the controllable current source; and

the isolated buck-type converter is configured to provide a DC output voltage to the output of the isolated buck-type converter.

5. The resonant converter of claim 1, wherein the isolated buck-type converter comprises one of the group consisting of:

a half-bridge converter, a full-bridge converter and a push-pull converter.

6. The resonant converter of claim 5, wherein the isolated buck-type converter comprises a push-pull converter, the push-pull converter comprising:

a transformer having a first primary winding, a second primary winding, a first secondary winding, and a second secondary winding, wherein the controllable current source is coupled to a node between the first and second primary windings to form a primary center tap;

a first primary switch coupled between the first primary winding and the controllable current source; and

a second primary switch coupled between the second primary winding and the controllable current source.

7. The resonant converter of claim 6, wherein the push-pull converter further comprises:

a first secondary diode coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary diode coupled between the second secondary winding and the output of the isolated buck-type converter.

8. The resonant converter of claim 6, wherein the push-pull converter further comprises:

a first primary inductor coupled between the first primary winding and the first primary switch; and

a second primary inductor coupled between the second primary winding and the second primary switch.

9. The resonant converter of claim 6, wherein the push-pull converter further comprises:

a first secondary inductor coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary inductor coupled between the second secondary winding and the output of the isolated buck-type converter.

10. The resonant converter of claim 6, wherein the push-pull converter further comprises:

a first secondary switch coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary switch coupled between the second secondary winding and the output of the isolated buck-type converter.

11. The resonant converter of claim 5, wherein the isolated buck-type converter comprises a full-bridge converter, the full-bridge converter comprising:

a transformer having a first primary winding, a first secondary winding, and a second secondary winding;

a first primary switch coupled between a first terminal of the first primary winding and the controllable current source;

a second primary switch coupled between a second terminal of the first primary winding and the controllable current source;

a third primary switch coupled between the first terminal of the first primary winding and the controllable current source, wherein the first primary switch and the third primary switch are coupled to the first terminal of the first primary winding through a common node; and

a fourth primary switch coupled between the second terminal of the first primary winding and the controllable current source, wherein the second primary switch and the fourth primary switch are coupled to the second terminal of the first primary winding through a common node.

12. The resonant converter of claim 11, wherein the full-bridge converter further comprises:

a first secondary diode coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary diode coupled between the second secondary winding and the output of the isolated buck-type converter.

13. The resonant converter of claim 11, wherein the full-bridge converter further comprises a primary inductor coupled between the first terminal of the first primary winding and the common node of the first primary switch and the third primary switch.

14. The resonant converter of claim 11, wherein the full-bridge converter further comprises a secondary inductor coupled between a common node between the first and second secondary windings and the output of the isolated buck-type converter.

15. The resonant converter of claim 11, wherein the full-bridge converter further comprises:

a first secondary switch coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary switch coupled between the second secondary winding and the output of the isolated buck-type converter.

16. The resonant converter of claim 5, wherein the isolated buck-type converter comprises a half-bridge converter, the half-bridge converter comprising:

a transformer having a first primary winding, a first secondary winding, and a second secondary winding;

a first primary switch coupled between a first terminal of the first primary winding and the controllable current source; and

a second primary switch coupled between the first terminal of the first primary winding and the controllable current source, wherein the first primary switch and the second primary switch are coupled to the first terminal of the first primary winding through a common node.

17. The resonant converter of claim 16, wherein the half-bridge converter further comprises:

a first secondary diode coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary diode coupled between the second secondary winding and the output of the isolated buck-type converter.

18. The resonant converter of claim 16, wherein the half-bridge converter further comprises a primary inductor coupled between the first terminal of the first primary winding and the common node of the first primary switch and the second primary switch.

19. The resonant converter of claim 16, wherein the half-bridge converter further comprises a secondary inductor coupled between a common node between the first and second secondary windings and the output of the isolated buck-type converter.

20. The resonant converter of claim 16, wherein the half-bridge converter further comprises:

a first secondary switch coupled between the first secondary winding and the output of the isolated buck-type converter; and

a second secondary switch coupled between the second secondary winding and the output of the isolated buck-type converter.