Magnetic integrated circuit for multiphase interleaved flyback converter and controlling method thereof

• US 7,983,063 B2
• Filed: 04/07/2008
• Issued: 07/19/2011
• Est. Priority Date: 08/16/2007
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Peng, Ming Hsien, Lu, Zengyi, Chen, Wei
• Primary Examiner(s): Laxton; Gary L
• Application Number:
  US12/098,684
• Publication Number:
  US 20090046486A1
• Time in Patent Office: 1,198 Days
• Field of Search: 363/16, 363/21.12, 363/65, 363/71, 363/97, 363/131, 363/39, 363/45
• US Class Current: 363/65
• CPC Class Codes: H01F 27/385 for reducing harmonics
• 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

The configurations of an interleaved flyback converter and a controlling method thereof are provided. The proposed two-phase interleaved flyback converter includes a transformer including a first primary winding having a first terminal, a first secondary winding having a first terminal, a second primary winding having a second terminal, a second secondary winding having a second terminal and a magnetic coupled core device, wherein the first primary, the first secondary, the second primary and the second secondary windings are wound therein, and the first terminal of the first primary winding has a polarity the same as that of any of the first terminal of the first secondary winding, the second terminal of the second primary winding and the second terminal of the second secondary winding so as to eliminate a ripple of a channel current of the converter.

Claims

1. A two-phase interleaved flyback converter, comprising:

an output capacitor having a first and a second terminals;

a transformer comprising;

a first primary winding having a first terminal selectively connected to a DC power source and a second terminal;

a first secondary winding having a first terminal connected to the output capacitor via a first switch and a second terminal;

a second primary winding having a first terminal and a second terminal selectively connected to the DC power source;

a second secondary winding having a first terminal and a second terminal connected to the output capacitor via a second switch; and

a magnetic coupled core device, wherein the first primary, the first secondary, the second primary and the second secondary windings are wound therein, and the first terminal of the first primary winding has a polarity the same to any of the first terminal of the first secondary winding, the first terminal of the second primary winding and the second terminal of the second secondary winding so as to eliminate a ripple of a channel current of the converter;

a first main circuit of a first flyback converter, comprising;

the first primary winding;

the first secondary winding;

the first switch having a first and a second terminals; and

a first diode having an anode and a cathode; and

a second main circuit of a second flyback converter, comprising;

the second primary winding;

the second secondary winding;

the second switch having a first and a second terminals; and

a second diode having an anode and a cathode, wherein the second terminal of the first primary winding is coupled to the first terminal of the first switch, the second terminal of the first switch is grounded, the first terminal of the second primary winding is coupled to the first terminal of the first primary winding, the second terminal of the second primary winding is coupled to the first terminal of the second switch, the second terminal of the second switch is grounded, the first terminal of the first secondary winding is coupled to the cathode of the first diode, the anode of the first diode is coupled to the first terminal of the output capacitor, the second terminal of the first secondary winding is coupled to the second terminal of the output capacitor, the first terminal of the second secondary winding is coupled to the cathode of the second diode, the anode of the second diode is coupled to the first terminal of the output capacitor, and the second terminal of the second secondary winding is coupled to the second terminal of the output capacitor.

2. A converter according to claim 1, wherein the first terminal of the output capacitor is grounded.

3. A converter according to claim 2, wherein the first terminals of the first and the second primary windings receive a DC input voltage, and the output capacitor outputs an output voltage.

4. A converter according to claim 1, wherein the core device comprises a magnetic core having a first and a second core legs, the first core leg is mounted with the first primary and the first secondary windings, the first core leg has a first air gap, the second core leg has a second air gap, and the second core leg is mounted with the second primary and the second secondary windings.

5. A converter according to claim 1, wherein the core device comprises a magnetic core having a first to a third core legs, the first core leg is mounted with the first primary and the first secondary windings, the first core leg has the first air gap, the second core leg has the second air gap, the third core leg has the third air gap, and the third core leg is mounted with the second primary and the second secondary windings.

6. A converter according to claim 1, wherein the core device comprises a magnetic core having a first to a fourth core legs, the second core leg is mounted with the first primary and the first secondary windings, the third core leg is mounted with the second primary and the second secondary windings, and the first core leg has a first air gap and the fourth core leg has a second air gap for storing energies transmitted by the transformer.

7. A converter according to claim 1, wherein the core device comprises two magnetic cores, each of the magnetic cores has a first and a second core legs, the second core leg of the first magnetic core and the first core leg of the second magnetic core are mounted with the first primary and the first secondary windings, the second core leg of the second magnetic core is mounted with the second primary and the second secondary windings.

8. A converter according to claim 1, wherein the core device comprises a first to a third magnetic cores, each of the magnetic cores has a first and a second core legs, the second core leg of the first magnetic core and the first core leg of the second magnetic core are mounted with the first primary and the first secondary windings, the second core leg of the second magnetic core and the first core leg of the third magnetic core are mounted with the second primary and the second secondary windings, the second core leg of the first magnetic core has a first air gap, and the first core leg of the third magnetic core has a second air gap.

9. A converter according to claim 1, wherein the first switch has a first control signal and the second switch has a second control signal, and a phase-shift angle between the first and second control signals is 180 degrees.

10. A controlling method for a multiphase interleaved flyback converter, comprising the steps of:

providing the converter with a transformer having a plurality of primary windings, each of which has a first terminal selectively connected to a DC power source and a second terminal, a plurality of secondary windings, each of which has a first terminal connected to an output capacitor, having a first terminal and a second terminal, via a switch and a second terminal, and a plurality of main circuits of flyback converters, each of which has the primary and the secondary windings, the switch and a diode, having a first primary winding and a second primary winding, a first secondary winding and a second secondary winding, a first switch and a second switch, each of which has a first terminal and a second terminal, and a first diode and a second diode, each of which has an anode and a cathode;

causing the second terminal of the first primary winding coupled to the first terminal of the first switch, the second terminal of the first switch grounded, the first terminal of the second primary winding coupled to the first terminal of the first primary winding, the second terminal of the second primary winding coupled to the first terminal of the second switch, the second terminal of the second switch grounded, the first terminal of the first secondary winding coupled to the cathode of the first diode, the anode of the first diode coupled to the first terminal of the output capacitor, the second terminal of the first secondary winding coupled to the second terminal of the output capacitor, the first terminal of the second secondary winding coupled to the cathode of the second diode, the anode of the second diode coupled to the first terminal of the output capacitor, and the second terminal of the second secondary winding coupled to the second terminal of the output capacitor; and

making the first terminal of the primary winding of a first one of the flyback converters has a polarity the same as that of any of the first terminal of the secondary winding of the first one of the flyback converters and all the second terminals of the primary and the secondary windings of the remaining flyback converters so as to eliminate a ripple of a channel current of the transformer.

11. A method according to claim 10, wherein each of the plurality of main circuits further comprises at least one magnetic core having at least two core legs.

12. A method according to claim 10, wherein the converter is a two-phase interleaved flyback converter.

13. A two-phase interleaved flyback converter, comprising:

a first flyback converter having a first primary winding,

an output capacitor having a first terminal and a second terminal;

a first secondary winding, a first switch and a first diode; and

a second flyback converter having a second primary winding, a second secondary winding, a second switch and a second diode, wherein each of the primary and secondary windings and switches has a first terminal and a second terminal, each of the diodes has an anode and a cathode, the second terminal of the first primary winding is coupled to the first terminal of the first switch, the second terminal of the first switch is grounded, the first terminal of the second primary winding is coupled to the first terminal of the first primary winding, the second terminal of the second primary winding is coupled to the first terminal of the second switch, the second terminal of the second switch is grounded, the first terminal of the first secondary winding is coupled to the cathode of the first diode, the anode of the first diode is coupled to the first terminal of the output capacitor, the second terminal of the first secondary winding is coupled to the second terminal of the output capacitor, the first terminal of the second secondary winding is coupled to the cathode of the second diode, the anode of the second diode is coupled to the first terminal of the output capacitor, the second terminal of the second secondary winding is coupled to the second terminal of the output capacitor,

and the second secondary winding of the second flyback converter generates an output current when a current on the first primary winding of the first flyback converter is relatively increased.

14. A converter according to claim 13 further comprising a magnetic core having a first and a second core legs, wherein the first primary and the first secondary windings are wound on the first core leg and the second primary and the second secondary windings are wound on the second core leg.

15. A converter according to claim 13, wherein each of the first and the second flyback converters further comprises:

a rectifier output circuit coupled between the respective secondary winding thereof and the output capacitor.