VOLTAGE CONVERTER

Description

[0001] The invention relates to a voltage converter.

[0002] In particular, the invention relates to a voltage transformer for a high-voltage switchgear. Such a voltage transformer transforms high alternating voltages proportionally and with phase accuracy to lower values ​​for measurement, protection, or control purposes. For this purpose, an inductive voltage transformer typically has at least one magnetic core arranged in a metallic encapsulating housing, around which a primary winding and (at least) one secondary winding run. The correct arrangement and adequate fixation of the active components (magnetic cores with windings) of the voltage transformer in the encapsulating housing are very important due to the nature of the high-voltage electric field. Incorrect arrangement or inadequate fixation of the active components can lead to damage or even total failure of the voltage transformer.

[0003] Inductive voltage transformers are known from WO 2017 / 036715 A1, EP 2 887 368 A1, JP 2004 055740 A and EP 2 144 261 A1, in each of which a magnetic core is connected to a cover by means of a holder.

[0004] The invention is based on the object of providing a voltage converter which is improved in particular with regard to the fastening but also the positioning of its active parts and the number of components.

[0005] The object is achieved according to the invention by a voltage converter having the features of claim 1.

[0006] Advantageous embodiments of the invention are the subject of the subclaims.

[0007] The cover, for example, closes the encapsulation housing of the voltage converter. The design of the cover with a positioning socket for each magnetic core enables simple and precise positioning of each magnetic core without the need for positioning gauges or similar aids. The holder of a magnetic core with two frame elements enables mechanical fixation of the magnetic core, which is mounted on a positioning socket, between the two frame elements. The holder can clamp the magnetic core to the holder and generate electric fields. The invention thus simplifies the assembly of the voltage converter and can reduce the number of components of the voltage converter for fixing and clamping the active parts and for generating electric fields in the desired manner.

[0008] In the invention, the holder for each magnetic core has clamping elements that clamp the magnetic core to the holder. According to the invention, the clamping elements of the holder for each magnetic core comprise two clamping elements and a clamping rod connecting the two clamping elements. Each clamping element is arranged in a form-fitting manner between adjacent ends of the two frame elements of the holder, and the clamping rod runs along the winding leg of the magnetic core. Thus, the holder for a magnetic core enables the magnetic core to be clamped to the holder by clamping elements that are positively connected to the two frame elements and pressed against the magnetic core.

[0009] For example, each clamping element of the magnetic core holder is arranged at a transition area between a side leg and the winding leg of the magnetic core. The transition area, for example, has a curved surface against which the clamping element rests. This allows the clamping elements to be easily pressed against the curved surface of the transition area to clamp the magnetic core by sliding them along this surface on the tensioning rod. For example, magnetic cores designed as cut-core cores have transition areas between the side legs and the winding leg with curved surfaces and are therefore particularly suitable for this embodiment of the invention.

[0010] The tension rod of the holder of each magnetic core, for example, has at least one end region with a thread, guided by a clamping element, onto which a screw element is screwed, which presses the clamping element against the magnetic core. This allows a magnetic core to be clamped to its holder in a simple manner by tightening at least one screw element.

[0011] In a further embodiment of the invention, each frame element of the holder for each magnetic core has a shield with a surface that faces the windings arranged around the magnetic core. The shield runs, for example, on both sides of the windings arranged around the magnetic core, partially around the winding leg of the magnetic core and / or along both side legs and / or along the base leg. In these embodiments of the invention, the holder for each magnetic core therefore comprises shields arranged on the frame elements for shielding electrical fields, for example to avoid high field strengths at the edges of the frame elements. The shields integrated into the frame elements advantageously allow separate or additional shields to be omitted or reduced.

[0012] In a further embodiment of the invention, the base leg of each magnetic core is positively mounted on the positioning socket of each magnetic core. In other words, in this embodiment of the invention, the base leg of each magnetic core is mounted in a positioning socket of the cover. This embodiment of the invention enables a space-saving design of the voltage converter, in which the windings of the voltage converter run essentially in planes orthogonal to the cover.

[0013] In a further embodiment of the invention, each frame element is detachably connected to the cover, for example, by at least one screw connection. This allows the frame elements of the magnetic core holder to be easily mounted on the cover after the magnetic core has been positioned in a positioning socket.

[0014] In a further embodiment of the invention, the voltage converter has three magnetic cores. For example, the winding limbs of the magnetic cores are arranged in a star configuration at an angle of 120 degrees to each other. This enables, in particular, a practical design of the voltage converter for three-phase alternating voltages.

[0015] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings. FIG 1 a perspective view of a first embodiment of a voltage converter, FIG 2 a perspective view of the Figure 1shown voltage converter in the area of ​​a positioning detection, FIG 3 a perspective view of a second embodiment of a voltage converter.

[0016] Corresponding parts are provided with the same reference numerals in the figures.

[0017] Figure 1 (FIG 1 ) shows a perspective view of a first embodiment of a voltage converter 1. The voltage converter 1 is designed for single-phase alternating voltages. The voltage converter 1 comprises a cover 3, a primary winding 5, a secondary winding, an electrode 7, a magnetic core 9, and a holder 11 for the magnetic core 9.

[0018] The cover 3 closes an encapsulating housing (not shown) in which the primary winding 5, the secondary winding, the electrode 7, the magnetic core 9 and the holder 11 are arranged.

[0019] The magnetic core 9 comprises a winding leg 12, around which the primary winding 5 and the secondary winding are arranged, a base leg 13 spaced from the winding leg 12 and running parallel to the winding leg 12, and two side legs 14, each connecting the winding leg 12 and the base leg 13 and running perpendicular to the winding leg 12 and the base leg 13. The magnetic core 9 is designed as a cut strip core. The transition region 16 between a side leg 14 and the winding leg 12 and the transition region 17 between a side leg 14 and the base leg 13 each have a curved outer surface 19. The primary winding 5 runs around the secondary winding, so that the secondary winding in Figure 1 is not visible. One end of the primary winding 5 is connected to the electrode 7, which is arranged around a central portion of the primary winding 5.

[0020] The cover 3 has a positioning mount 21, which is designed to position the magnetic core 9 on the cover 3. The base leg 13 of the magnetic core 9 is positively mounted on the positioning mount 21.

[0021] Figure 2 (FIG 2 ) shows a section of the Figure 1 shown voltage transformer 1 in the area of ​​the positioning detection 21 in a perspective view.

[0022] The bracket 11 comprises two frame elements 23, two clamping elements 25, a tension rod 27 and two screw elements 29.

[0023] The frame elements 23 are arranged on opposite sides of the magnetic core 9 and each run along the two side legs 14 and the base leg 13. The frame elements 23 thus each have a substantially U-shaped configuration. Each frame element 23 is detachably connected to the cover 3 by a screw connection 31. Furthermore, each frame element 23 has a shield 33 with a curved surface that faces the windings (primary winding 5, secondary winding) arranged around the magnetic core 9. The shield 33 runs on both sides of the windings, partially circumferentially around the winding leg 12, as well as along both side legs 14 and the base leg 13, whereby the shields 33 of the two frame elements 23 do not touch each other.In particular, the shields 33 of the two frame elements 23 in the region of the winding leg 12 are spaced from each other on both sides of the windings by a gap 35 which prevents an electrical connection of the frame elements 23 in the core window in the electromagnetic near field of the windings.

[0024] Each clamping element 25 is arranged in a form-fitting manner between adjacent ends of the two frame elements 23 at a transition region 16 between a side leg 14 and the winding leg 12 of the magnetic core 9. The tension rod 27 connects the two clamping elements 25 to one another and runs along the winding leg 12. Each end region of the tension rod 27 is guided by a clamping element 33 and has a thread onto which a screw element 29 is screwed, which presses the clamping element 25 against the curved surface 19 of the transition region 16 between a side leg 14 and the winding leg 12.

[0025] Figure 3 (FIG 3 ) shows a perspective view of a second embodiment of a voltage converter 1. The voltage converter 1 is designed for three-phase alternating voltages. The voltage converter 1 therefore has three magnetic cores 9, around each of which a primary winding 5 and a secondary winding are arranged. Each magnetic core 9 is like the magnetic core 9 of the Figures 1 and 2 shown voltage transformer 1. The winding legs 12 of the magnetic cores 9 are arranged in a star shape at an angle of 120 degrees to each other. The base legs 13 of the magnetic cores 9 are analogous to the magnetic core 9 of the Figures 1 and 2 shown voltage transformer 1 are each mounted positively in a positioning socket 21 of a cover 3 of the voltage transformer 1. Furthermore, the voltage transformer 1 has a holder 11 for each magnetic core 9, which, like the holder 11 of the magnetic core 9 of the Figures 1 and 2shown voltage transformer 1 and is fastened to the cover 3 with a screw connection 31.

[0026] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the claims.

Claims

1. Voltage transformer (1), comprising - at least one magnetic core (9) having a winding leg (12) around which windings of the voltage transformer (1) are arranged, a base leg (13) spaced apart from the winding leg (12), and two side legs (14) which each interconnect the winding leg (12) and the base leg (13), - a cover (3) which comprises a positioning receptacle (21) for each magnetic core (9), in which receptacle the magnetic core (9) is positioned on the cover (3), - a holder (11) for each magnetic core (9), comprising two mutually spaced frame elements (23) which extend on mutually opposing sides of the magnetic core (9), in each case along the two side legs (14) and the base leg (13), and are in each case connected to the cover (3), wherein - the holder (11) of each magnetic core (9) comprises tensioning elements (25, 27) by which the magnetic core (9) is braced with the holder (11), characterised in that - the tensioning elements (25, 27) of the holder (11) of each magnetic core (9) comprise two clamping elements (25) and a tie rod (27) connecting the two clamping elements (25), each clamping element (25) is arranged in a form-fitting manner between adjacent ends of the two frame elements (23) of the holder (11) and the tie rod (27) extends along the winding leg (12) of the magnetic core (9).

2. Voltage transducer (1) according to claim 1, wherein each clamping element (25) is arranged at a transition region (16) between a side leg (14) and the winding leg (12) of the magnetic core (9).

3. Voltage transducer (1) according to claim 2, wherein the transition region (16) comprises a curved surface (19) on which the clamping element (25) rests.

4. Voltage transducer (1) according to any of claims 1 to 3, wherein the tie rod (27) of the holder (11) of each magnetic core (9) comprises at least one end region which is guided through a clamping element (25) and comprises a thread, onto which a screw element (29) is screwed which presses the clamping element (25) onto the magnetic core (9).

5. Voltage transformer (1) according to any of the preceding claims, wherein each frame element (23) of the holder (11) of each magnetic core (9) comprises a shielding (33) having a surface which faces the windings arranged around the magnetic core (9).

6. Voltage transformer (1) according to claim 5, wherein the shielding (33) extends on both sides of the windings arranged around the magnetic core (9), partially around the winding leg (12) of the magnetic core (9).

7. Voltage transformer (1) according to either claim 5 or claim 6, wherein the shielding (33) extends along both side legs (14) of the magnetic core (9).

8. Voltage transformer (1) according to any of claims 5 to 7, wherein the shielding (33) extends along the base leg (13) of the magnetic core (9).

9. Voltage transformer (1) according to any of the preceding claims, wherein the base leg (13) of the magnetic core (9) is mounted in a form-fitting manner at the positioning recess (21) of each magnetic core (9).

10. Voltage transformer (1) according to any of the preceding claims, wherein each frame element (23) is detachably connected to the cover (3).

11. Voltage transformer (1) according to any of the preceding claims, wherein each frame element (23) is connected to the cover (3) by at least one screw connection (31).

12. Voltage transformer (1) according to any of the preceding claims comprising three magnetic cores (9).

13. Voltage transformer (1) according to claim 12, wherein the winding legs (12) of the magnetic cores (9) are arranged in a start shape at an angle of 120 degrees relative to one another.