Electrical power supply suitable in particular for DC plasma processing

• US 20030021125A1
• Filed: 06/27/2002
• Published: 01/30/2003
• Est. Priority Date: 07/16/2001
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: CP Automation S.A.
• Inventors: Muller, Frederic, Bulliard, Albert, Rufer, Alfred-Christophe, Zimmermann, Claudio
• Granted Patent: US 6,567,278 B2
• Time in Patent Office: Days
• US Class Current: 363/15
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02M 3/33571 Half-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer

Abstract

A power supply comprising a DC-DC converter which comprises

(a) a first transformer (11); (b) a second transformer (12);

(c) a first H-bridge switching circuit (13) for selectively connecting a primary DC source (14) to the primary winding of said first transformer;

(d) a second H-bridge (15) switching circuit for selectively connecting said primary DC source (14) to the primary winding of said second transformer (12);

(e) a bridge rectifier circuit (16) connected to the secondary windings of said first and second transformers; and

(f) a control circuit (17) for providing sets of control pulses for effecting switching of switching elements of the first and the second H-bridge switching circuits (13, 15).

Claims

1. A power supply comprising a DC-DC converter which comprises

(a) a first transformer having a primary winding and a secondary winding, said primary winding and said secondary winding of said first transformer having the same winding polarity;

(b) a second transformer having a primary winding and a secondary winding, said primary winding and said secondary winding of said second transformer having opposite winding polarities;

said secondary winding of said first transformer having a terminal which is a first transformer output terminal,

another terminal of said secondary winding of said first transformer and a terminal of said secondary winding of said second transformer being connected with each other at a node which is a second transformer output terminal, and

said secondary winding of said second transformer having a terminal which is a third transformer output terminal;

(c) a first H-bridge switching circuit for selectively connecting a primary DC source to the primary winding of said first transformer, said first H-bridge switching circuit having a leading leg and a lagging leg, each of these legs including switching elements;

(d) a second H-bridge switching circuit for selectively connecting said primary DC source to the primary winding of said second transformer, said second H-bridge switching circuit having a leading leg and a lagging leg, each of these legs including switching elements;

(e) a bridge rectifier circuit connected to the secondary windings of said first and second transformers;

(f) a control circuit for providing

(f.1) a first set of control pulses for effecting switching of switching elements of said leading leg of said first H-bridge switching circuit,

(f.2) a second set of control pulses for effecting switching of switching elements of said lagging leg of said first H-bridge switching circuit,

said second set of control pulses having an adjustable first phase delay with respect to said first set of control pulses,

(f.3) a third set of control pulses for effecting switching of switching elements of said leading leg of said second H-bridge switching circuit,

said third set of control pulses having an adjustable second phase delay with respect to said first set of control pulses,

(f.4) a fourth set of control pulses for effecting switching of switching elements of said lagging leg of said second H-bridge switching circuit,

said fourth set of control pulses having an adjustable third phase delay with respect to said third set of control pulses.

2. A power supply according to claim 1, wherein said third phase delay is equal to said first phase delay.

3. A power supply according to claim 1, wherein said control pulses of all said sets of control pulses have all one and the same predetermined duration.

6. A power supply according to claim 1 or 4, wherein said bridge rectifier circuit has

a first input terminal connected to said first transformer output terminal,

a second input terminal connected to said second transformer output terminal,

a third input terminal connected to said third transformer output terminal, and

output terminals.

7. A power supply according to claim 1 or 4, wherein said bridge rectifier circuit includes six diodes.

8. A power supply according to claim 1 or 4, wherein said bridge rectifier circuit comprises

(i) a first bridge rectifier circuit including four diodes and having

a first input terminal connected to said first transformer output terminal, and

a second input terminal connected to said second transformer output terminal,

(ii) a second bridge rectifier circuit including four diodes and having

a first input terminal connected to said second transformer output terminal, and

a second input terminal connected to said third transformer output terminal, and

(iii) output terminals.

9. A power supply comprising a combination of a plurality of DC-DC converters of the kind defined in claim 1 or 4.

10. A power supply according to claim 1, further comprising means for performing zero voltage switching of the switching elements of said H-bridge switching circuits.

11. A power supply according to claim 10, wherein said means for performing zero voltage switching comprise the inductance of a first inductor connected in series with the primary winding of said first transformer, the inductance of a second inductor connected in series with the primary winding of said second transformer, and capacitors each being connected in parallel with a respective switching element.

12. A power supply according to claim 11, wherein the leakage inductance of said first transformer is used instead of said first inductor or the leakage inductance of said second transformer is used instead of said second inductor.

13. A power supply according to claim 11, wherein the leakage inductance of said first transformer is used instead of said first inductor and the leakage inductance of said second transformer is used instead of said second inductor.

14. A power supply according to claim 13, wherein leakage inductances of said first transformer and said second transformer are exclusively used as inductances for performing said zero voltage switching.

15. A power supply according to claim 13, wherein leakage inductances of said first transformer and said second transformer are exclusively used instead of an output filtering inductor which would otherwise be connected in series with an output terminal of said bridge rectifier.

16. A power supply according to claim 11, wherein said means for performing said zero voltage switching further comprise a capacitor connected across the output terminals of said bridge rectifier, said capacitor serving for reducing the resetting time of said inductances for performing said zero voltage switching.

23. A power supply according to claim 1 or 4 characterized in that it is so configured and dimensioned that it is particularly suitable for plasma processing.

4. A power supply comprising a DC-DC converter which comprises

(a) a first transformer having a primary winding and a secondary winding, said primary winding and said secondary winding of said first transformer having the same winding polarity;

(b) a second transformer having a primary winding and a secondary winding, said primary winding and said secondary winding of said second transformer having opposite winding polarities;

said secondary winding of said first transformer having a terminal which is a first transformer output terminal,

another terminal of said secondary winding of said first transformer and a terminal of said secondary winding of said second transformer being connected with each other at a node which is a second transformer output terminal, and

said secondary winding of said second transformer having a terminal which is a third transformer output terminal;

(c) a first half bridge switching circuit and a second half bridge switching circuit for selectively connecting a primary DC source to the primary winding of said first transformer and to the primary winding of said second transformer, said first half bridge switching circuit forming a first leg, said second half bridge switching circuit forming a second leg, each of these legs including switching elements;

(d) a circuit formed by a series connection of a first capacitor and a second capacitor, said circuit being connected in parallel with said first leg and with said second leg,

said circuit formed by said series connection of said first capacitor and said second capacitor having a node which a terminal of each of said first and second capacitors is connected to,

said node being connected to a terminal of each of said primary windings of said first and said second transformers;

(e) a bridge rectifier circuit connected to the secondary windings of said first and second transformers;

(f) a control circuit for providing

(f.1) a first set of control pulses for effecting switching of switching elements of said first leg formed by said first half bridge switching circuit, each of said control pulses of said first set having an adjustable duration,

(f.2) a second set of control pulses for effecting switching of switching elements of said second leg formed by said second half bridge switching circuit, each of said control pulses of said second set having an adjustable duration,

said second set of control pulses having a predetermined phase delay with respect to said first set of control pulses.

5. A power supply according to claim 4, wherein said adjustable duration of each of the control pulses of said second set of control pulses is equal to said adjustable duration of each of the control pulses of said first set of control pulses.

17. A power supply according to claim 4, wherein said means for performing zero voltage switching comprise the inductance of a first inductor connected in series with the primary winding of said first transformer, the inductance of a second inductor connected in series with the primary winding of said second transformer, and capacitors each being connected in parallel with a respective switching element.

18. A power supply according to claim 17, wherein the leakage inductance of said first transformer is used instead of said first inductor or the leakage inductance of said second transformer is used instead of said second inductor.

19. A power supply according to claim 17, wherein the leakage inductance of said first transformer is used instead of said first inductor and the leakage inductance of said second transformer is used instead of said second inductor.

20. A power supply according to claim 19, wherein leakage inductances of said first transformer and said second transformer are exclusively used as inductances for performing said zero voltage switching.

21. A power supply according to claim 19, wherein leakage inductances of said first transformer and said second transformer are exclusively used instead of an output filtering inductor which would otherwise be connected in series with an output terminal of said bridge rectifier.

22. A power supply according to claim 17, wherein said means for performing said zero voltage switching further comprise a capacitor connected across the output terminals of said bridge rectifier, said capacitor serving for reducing the resetting time of said inductances for performing said zero voltage switching.