Power-electronic device comprising a transformer unit and method

Patent metadata

Field	Value
Publication number	US-11942785-B2
Application number	US-202017076084-A
Country	US
Kind code	B2
Filing date	Oct 21, 2020
Priority date	Apr 24, 2018
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

The disclosure relates to a power electronics device having at least two inverters and a transformer apparatus having a core arrangement, at least one primary winding and at least one secondary winding that wind around the core arrangement at least in sections.

First claim

The invention claimed is:

1. A power electronics device comprising at least two inverters and a transformer apparatus, wherein:
the inverters are electrically connected on an AC side thereof to the transformer apparatus on a primary side thereof, and the transformer apparatus is configured to be electrically connected on a secondary side thereof to a power distribution grid,
the transformer apparatus comprises a core arrangement, and at least one primary winding and at least one secondary winding that wind around the core arrangement at least in sections,
the core arrangement comprises at least two rows of core limbs arranged adjacent to one another, wherein the core limbs are connected to one another via yoke connections in each row, wherein:
at least one special electrical connection is present between a phase output of an inverter and a primary winding start of a primary winding of the transformer apparatus, wherein the following applies to such a special electrical connection:
the primary winding start of the primary winding is electrically connected to exactly one phase output of one of the inverters and the primary winding is essentially wound around a core section, adjoining a first core window, of a row,
and at least one second primary winding, electrically connected to at least one of the inverters, of the same phase is essentially wound around a core section adjoining a second core window of another row, which core section is spaced from the first core window, wherein a secondary winding of the same phase is wound in sections around a core section adjoining the first core window and around a core section adjoining the second core window.

2. The power electronics device as claimed in claim 1 , wherein the secondary winding of the same phase is wound in sections around a core section adjoining the first core window and around a core section adjoining the second core window, wherein the core sections are spaced from the respective other core window.

3. The power electronics device as claimed in claim 1 , wherein in the special electrical connection the core sections around which the primary winding, which is connected, at its primary winding start, to the special electrical connection, and the at least second primary winding and the secondary winding are wound, are core limbs.

4. The power electronics device as claimed in claim 1 , wherein the special electrical connection is free from coils.

5. The power electronics device as claimed in claim 1 , wherein the at least one phase output of the at least two inverters is connected to the transformer apparatus on the primary side via a special electrical connection.

6. The power electronics device as claimed in claim 1 , wherein the transformer apparatus comprises one secondary winding per phase.

7. The power electronics device as claimed in claim 1 , wherein the at least two inverters are configured such that, during operation, the phases of each inverter have a phase shift with respect to one another, such that the sum of the phase shifts corresponds to 360 degrees, and the primary winding ends of the primary windings electrically connected to an inverter are electrically connected to one another at a star point or in a delta connection.

8. The power electronics device as claimed in claim 1 , wherein the at least two inverters are three-phase inverters.

9. The power electronics device as claimed in claim 1 , wherein the secondary winding ends are electrically connected to one another at a star point.

10. The power electronics device as claimed in claim 1 , wherein the transformer apparatus comprises at least two phase terminals on the secondary side, which phase terminals are each designed for the connection of a line of a power distribution grid, wherein the phase terminals of the transformer apparatus are electrically connected to one another by way of a star connection of capacitors or a delta connection of capacitors.

11. The power electronics device as claimed in claim 1 , wherein the core arrangement comprises a stack of single-phase or multiphase transformer cores that are formed in a core or jacket design, wherein the transformer cores are arranged in a row in the direction of the core limbs with yoke connections facing one another, and the adjacent yoke connections are formed together and/or are arranged adjacent to one another and/or parallel and spaced from one another.

12. The power electronics device as claimed in claim 1 , wherein at least one yoke connection, arranged between core limbs of two adjacent rows, for forming a leakage channel for transverse fluxes comprises an insert made from ferromagnetic material.

13. The power electronics device as claimed in claim 1 , wherein at least one yoke connection, arranged between core limbs of two adjacent rows, has a thickness pointing parallel to the core limbs that is equal to or less than the thickness of the yoke connections terminating the core arrangement.

14. The power electronics device as claimed in claim 1 , wherein the number of rows corresponds to the number of inverters, wherein each row comprises a number of primary windings corresponding to the number of phases, and these primary windings are connected to a corresponding phase output of a common inverter via a special electrical connection.

15. The power electronics device as claimed in claim 1 , wherein a controller is included, which is designed and configured such that, during operation of the power electronics device, the clocking of the inverters is at least temporarily shifted with respect to one another such that, for at least one special electrical connection, the sum of the voltage present at the primary winding start of the primary winding and the voltage present at the at least second primary winding to the same secondary winding corresponds to a voltage profile with a higher clock frequency than the clock frequencies of the voltage profiles of the individual voltages.

16. A transformer apparatus having a core arrangement and at least two primary windings and at least one secondary winding, wherein the primary windings and the at least one secondary winding wind around the core arrangement at least in sections, wherein the transformer apparatus is configured and designed such that it is able to be used as a transformer apparatus of the power electronics device as claimed in claim 1 .

17. The power electronics device as claimed in claim 1 , wherein the transformer apparatus comprises a plurality of separate transformers that correspond, respectively, to the at least two inverters, and wherein each of the plurality of transformers are electrically connected on a primary side of the transformer to a respective one of the inverters and wherein each of the plurality of transformers on a secondary side of the transformers is connected together in series in each phase, respectively, prior to connection to a grid connection point.

Assignees

• Sma Solar Technology Ag

Inventors

• Umlauf Sebastian

Classifications

• H02J3/00142

  Oscillations concerning frequency · CPC title

• H02J3/01 Primary

  Arrangements for reducing harmonics or ripples · CPC title

• H01F27/26

  Fastening parts of the core together; Fastening or mounting the core on casing or support (on coil H01F27/30) · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H01F27/40

  Structural association with built-in electric component, e.g. fuse · CPC title