Power source and method for cooling such a power source

• US 9,641,093 B2
• Filed: 10/31/2012
• Issued: 05/02/2017
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Fronius International GmbH (G&K Privatstiftung)
• Original Assignee: Fronius International GmbH (G&K Privatstiftung)
• Inventors: Artelsmair, Bernhard, Schultschik, Christoph, Neuboeck, Johannes, Wolfsgruber, Stefan
• Primary Examiner(s): Benitez, Gustavo Rosario
• Application Number:
  US14/354,987
• Publication Number:
  US 20140301122A1
• Time in Patent Office: 1,644 Days
• CPC Class Codes: B23K 11/241 Electric supplies B23K11/248 takes precedence
• CPC Class Codes: H01F 27/10 Liquid cooling
• CPC Class Codes: H01F 38/085 Welding transformers
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/12 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: Y02P 70/10 Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

The invention relates to a power source (10) for providing a direct current, comprising a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16), and a supply circuit (48) for supplying the synchronous rectifier (16) and the actuation circuit (17), and to a method for cooling such a power source (10). For reduction of losses and improvement of efficiency, the synchronous rectifier (16) and the actuation circuit (17) and the supply circuit (48) thereof are integrated in the heavy-current transformer (12).

Claims

1. A power source (10) for providing a direct current, comprising a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and an actuation circuit for actuating the circuit elements (24) of the synchronous rectifier (16), and a supply circuit (48) for supplying the synchronous rectifier (16) and the actuation circuit (17), wherein the synchronous rectifier (16) and the actuation circuit (17) and the supply circuit (48) thereof are integrated in the heavy-current transformer (12) wherein, in order to form a multi-point contacting, at least four contacts (20, 21, 22, 23) are provided at the heavy-current transformer (12) for providing the direct current, whereby the direct current is at least halved and the contact losses are thus reduced, and wherein two first contacts (20, 21) of one polarity and two additional contacts (22, 23) of opposite polarity are each arranged opposite each other, wherein the two additional contacts (22, 23) are substantially arranged offset to each other by 90°

compared to the two first contacts (20, 21).

2. The power source (10) according to claim 1, wherein the circuit elements (24) of the synchronous rectifier (16) are connected without lines with the at least one secondary winding (14) of the heavy-current transformer (12).

3. The power source (10) according to claim 1, wherein the heavy-current transformer (12) comprises a plurality of, preferably at least 10, primary windings (13) connected in series, and a plurality of, preferably at least 10, secondary windings (14) with center tapping connected in parallel.

4. The power source (10) according to claim 1, wherein the heavy-current transformer (12) comprises an I-beam (25) of electrically conductive material, in recesses (25a) of which at least one respective ring core (15) is arranged, wherein one respective connection of each secondary winding (13) is directly contacted with one inner surface of the I-beam (25), and wherein the outer surfaces (28) of the I-beam (25) form the two first contacts (20, 21), and wherein the center tapping of the at least one secondary winding (14) of the heavy-current transformer (12) is connected with the I-beam (25) without lines.

5. The power source (10) according to claim 4, wherein the at least one primary winding (13) of the heavy-current transformer (12) is arranged to run through the at least one ring core (15).

6. The power source (10) according to claim 4, wherein respective contact plates (29) are located above the recesses (25a) of the I-beam (25), said contact plates (29) being of electrically conductive material and connected with the respectively other connections of each secondary winding (14) via the synchronous rectifier (16) and the actuation circuit (17), wherein the outer surfaces of the contact plates (29) form the two additional contacts (22, 23) of the power source (10).

7. The power source (10) according to claim 1, wherein one secondary winding (14) with center tapping is each formed by two metal sheets (44, 45) insulated from each other and being of electrically conductive material and having a substantially S-shaped mirror-inverted course around the cross-section of the ring core (15) and through the ring core (15), wherein the exterior surfaces (47) of the metal sheets (44, 45) form the contacts for the connection with the circuit elements (24) of the synchronous rectifier (16) or electrodes (7).

8. The power source (10) according to claim 6, wherein the I-beam (25) and the contact plates (29) of the heavy-current transformer (12) form a cube or ashlar-shaped unit, wherein cover plates (31) are arranged at the front faces of the I-beam (25), and wherein the cover plates (31) are formed of electrically conductive material and are adapted to be screwed to the contact plates (29), so that the contact plates (29) are connected electrically.

9. The power source (10) according to claim 4, wherein the I-beam (25) and/or contact plates (29) or the cover plates (31) and/or the metal sheets (44, 45) for forming the secondary winding (14) of the heavy-current transformer (12) are formed of copper or a copper alloy, preferably with a silver coating.

10. The power source (10) according to claim 1, wherein at the connections of a secondary winding (14) a current transducer (18) each is arranged for measuring the current through this secondary winding (14), said current transducers (18) being connected with the actuation circuit (17).

11. The power source (10) according to claim 10, wherein the current transducers (18) are arranged to be oriented substantially 90°

to the direction of the direct current.

12. The power source (10) according to claim 10, wherein the actuation circuit (17) is designed to activate the circuit elements (24) of the synchronous rectifier (16) at a preset point in time prior to reaching zero crossing of the current in the secondary winding (14).

13. The power source (10) according to claim 4, wherein channels (39) for feeding a cooling fluid are arranged in the I-beam (25) and contact plates (29), wherein two inlets (32) for feeding the cooling fluid and one outlet (33) for discharging the cooling fluid are arranged at an outer surface (28) of the I-beam (25), wherein the cooling channels (39) are arranged to extend from each inlet (32) to the contact plates (29) and via the I-beam (25) to the outlet (33).

14. The power source (10) according to claim 6, wherein the actuation circuit (17) and the synchronous rectifier (16) are arranged on at least one circuit board (35) which is arranged on the inner surface of at least one contact plate (29), and wherein each circuit board (35) of the synchronous rectifier (16) and of the actuation circuit (17) comprises openings (37) above which the circuit elements (24) are arranged, and wherein the inner surface of the contact plates (29), in the places of the openings (37) in the circuit board (35) of the synchronous rectifier (16), comprises protrusions (36), in particular pinnacle-shaped protrusions, so that the circuit elements (24) can be contacted without lines via the protrusions (36) protruding into the openings (37) on the circuit board (35) on the inner surface of the contact plates (29).

15. A method for cooling a power source (10) for providing a direct current, comprising a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16), by means of a cooling fluid, wherein the cooling fluid is guided in a contact plate and an I-beam of the heavy-current transformer such that first the at least one actuation circuit (17) and the synchronous rectifier (16) and then the at least one secondary winding (14) of the heavy-current transformer (12) are cooled.

16. The cooling method according to claim 15, wherein the cooling fluid is guided in a self-contained circuit.