VOLTAGE CONVERTER

Description

[0001] The invention relates to a voltage converter.

[0002] The invention relates in particular to a voltage transformer for a high-voltage switchgear. With such a voltage transformer, high voltages are proportionally and phase-accurately transformed to lower values ​​for measurement, protection, or control purposes. An inductive voltage transformer typically has at least one magnetic core around which a primary winding and at least one secondary winding are arranged. In specific operating states of a switchgear, for example, during certain commissioning tests, it is necessary to isolate the voltage transformer from the rest of the switchgear, as the voltage transformer could otherwise be damaged or destroyed. For this purpose, the voltage transformer can, for example, have an insulating device with which electrical connections between the voltage transformer and the rest of the switchgear can be disconnected.

[0003] Inductive voltage converters for high voltages are known from DE 10 2010 060696 A1 and WO 2016 / 012444 A1, the contact elements of which have a sliding contact with an electrode. DE 532 674 C discloses an adjustable wire resistor with a rolling contact guided along the wire windings.

[0004] The invention is based on the objective of providing a voltage converter whose contact with the contact element is improved, in particular reducing the wear of the contact element.

[0005] The problem is solved according to the invention by a voltage converter with the features of claim 1.

[0006] In the voltage converter according to the invention, the friction between the contact element and the electrode and / or the feedthrough contact is advantageously reduced, thus reducing the wear of the contact element.

[0007] Advantageous embodiments of the invention are the subject of the dependent claims.

[0008] A voltage transformer according to the invention enables the opening and closing of at least one current path between a primary winding and an associated feedthrough contact of the voltage transformer by rotating a carrier element on which a contact element is arranged for each of these current paths. In a first end position of the carrier element, the current path is closed by the contact element, and in a second end position of the carrier element, it is opened. In the first end position, the contact element contacts an electrode electrically connected to one end of the primary winding and / or the feedthrough contact via a rolling contact. This advantageously reduces the friction between the contact element and the electrode and / or the feedthrough contact, for example, compared to a sliding contact between the contact element and the electrode and / or the feedthrough contact (rolling friction instead of sliding friction).The lower friction also reduces the wear and tear of a rolling contact compared to a sliding contact, for example.

[0009] In one embodiment of the invention, each contact element has a first rolling contact which, in the first end position of the carrier element, contacts the electrode of the primary winding associated with the contact element, and a second rolling contact which, in the first end position of the carrier element, contacts the feedthrough contact associated with the contact element.

[0010] In other words, the aforementioned embodiment of the invention provides that each contact element has two rolling contacts, one of which, in the first end position, contacts the electrode of a primary winding and the other contacts a feedthrough contact, and which, in the second end position, are each disconnected from the electrode and the feedthrough contact. In this way, each contact element advantageously closes and closes an electrical connection between the electrode of a primary winding and the associated feedthrough contact, both on the electrode side and on the feedthrough contact side, by means of a low-friction rolling contact.

[0011] In a further embodiment of the invention, at least one rolling contact comprises a rolling bearing with an electrically conductive outer ring which, in the first end position of the support element, contacts the electrode of the primary winding associated with the contact element or the feedthrough contact associated with the contact element. In this embodiment of the invention, the electrical connection of the rolling contact to the electrode of a primary winding or a feedthrough contact is thus established by the outer ring of a rolling bearing.

[0012] In a further embodiment of the aforementioned design of the invention, each rolling contact comprising a rolling bearing has an electrically conductive holder in which the rolling bearing is arranged and which is electrically connected to the outer ring of the rolling bearing by a sliding contact. The electrical connection of the outer ring to the holder via the sliding contact advantageously avoids the risk of welding occurring due to high currents resulting from rapid transients, such as those caused between the outer ring and the holder by arcs generated by play between the outer ring and the holder.

[0013] In a further embodiment of the invention, at least one rolling contact has an electrically conductive ball mounted in an electrically conductive sliding bearing, which in the first end position of the carrier element contacts the electrode of the primary winding assigned to the contact element or the feedthrough contact assigned to the contact element.

[0014] In this embodiment of the invention, the electrical connection of the rolling contact to the electrode of a primary winding or a feedthrough contact is thus established by the ball mounted in the sliding bearing.

[0015] In a further embodiment of the invention, each rolling contact of a contact element is resiliently mounted on a base body of the contact element. This allows the position of the rolling contact on the contact element and the contact pressure of the rolling contact to flexibly adapt to the surface of the electrode of a primary winding or a feedthrough contact when contacting the electrode of a primary winding or a feedthrough contact.

[0016] According to the invention, each rolling contact of a contact element is resiliently mounted on a base body of the contact element by at least one leaf spring element, wherein each leaf spring element electrically connects the rolling contact, resiliently mounted by the leaf spring element, to the base body of the contact element. The resilient mounting of a rolling contact and the electrical connection of the rolling contact to the base body of the contact element by a leaf spring element has, for example, the advantage over the use of a helical spring that a leaf spring element has low inductance. In a further embodiment of the aforementioned configurations of the invention, each rolling contact is resiliently mounted in an opening of the base body of the contact element. Furthermore, each opening of the base body of a contact element in which a rolling contact is resiliently mounted can be surrounded by a wall of the base body with a convex outer surface.By mounting a roller contact in an opening in the base body of the contact element, the roller contact can be advantageously protected. Designing the opening with a surrounding wall having a suitable convex outer surface also advantageously provides electrical shielding for the roller contact.

[0017] In a further embodiment of the invention, the voltage transformer has three primary windings arranged at intervals around the axis of rotation of the support element. In particular, the primary windings can be arranged offset from one another by 120 degrees around the axis of rotation of the support element, and the support element can be rotatable by 60 degrees around the axis of rotation between the two end positions. These embodiments of the invention particularly realize a design of the voltage transformer suitable for three-phase alternating voltages.

[0018] In a further embodiment of the invention, the support element comprises a support plate on which each contact element is arranged, and a support shaft connected to the support plate through which the axis of rotation passes. The support plate is, for example, arranged in a plane between a first spatial region in which each primary winding is arranged and a second spatial region in which each bushing contact is arranged. These embodiments of the invention realize a geometrically simple and practical design and arrangement of the support element.

[0019] In a further embodiment of the invention, each feedthrough contact has a convex contact surface which, in the first end position of the carrier element, is contacted by a rolling contact. This embodiment of the invention advantageously enables a smooth connection and disconnection of a feedthrough contact to and from a rolling contact.

[0020] According to the invention, the voltage transformer has an encapsulated housing in which each primary winding, each bushing contact, the support element, and each contact element are arranged. This advantageously protects the components of the voltage transformer from adverse conditions such as humidity in the transformer's environment. Furthermore, the encapsulated housing can be made gas-tight, if required, to allow it to be filled with an insulating gas.

[0021] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings. These drawings show: FIG 1 a perspective view of a first embodiment of a voltage converter, FIG 2 a perspective view of the in Figure 1shown voltage converter in the area of ​​a contact element, Fig. 3 a sectional view of a contact element of the in Figure 1 The voltage converter shown, FIG. 4, is a perspective view of the voltage converter shown in FIG. 4. Figure 3 The contact element shown in FIG 5 schematically represents a rolling contact of a second embodiment of a voltage converter.

[0022] Corresponding parts are marked with the same reference symbols in the figures.

[0023] Figure 1 (FIG 1 Figure 1 shows a perspective view of a first embodiment of a voltage converter 1. The voltage converter 1 comprises an encapsulation housing 3, three primary windings 5, three secondary windings, three electrodes 7, three magnetic cores 9, three bushing contacts 11, a support element 13 and three electrically conductive contact elements 15. The voltage converter 1 is designed for three-phase alternating voltages.

[0024] The encapsulation housing 3 is shown in a cutaway view and comprises a housing shell 17, a housing cover 19, and a feedthrough 21. The housing shell 17 is closed at the top by the housing cover 19 and at the bottom by the feedthrough 21. On the feedthrough side, the housing shell 17 has a flange 23 on which the feedthrough 21 is arranged. The housing shell 17 is connected to the housing cover 19 and the feedthrough 21 by screw connections 25 and 27, respectively. The secondary windings, primary windings 5, electrodes 7, magnetic cores 9, feedthrough contacts 11, contact elements 15, and the support element 13 are arranged in the encapsulation housing 3.

[0025] The feedthrough contacts 11 are arranged on the feedthrough 21 and can each be electrically contacted from the outside through the feedthrough 21 in order to connect the feedthrough contacts 11 to electrical conductors, for example, of a switchgear. Each feedthrough contact 11 has a convex contact surface 29 facing the housing cover 19.

[0026] The support element 13 comprises a support shaft 31 and a support plate 33 arranged on the support shaft 31. The support element 13 is rotatable by 60 degrees between a first end position and a second end position about an axis of rotation 35, which coincides with the longitudinal axis of the support shaft 31. The housing shell 17 is essentially rotationally symmetrical with respect to the axis of rotation 35, which runs essentially centrally through the housing cover 19 and the feedthrough 21.

[0027] Each magnetic core 9 has a leg around which one of the secondary windings and one of the primary windings 5 ​​run. The primary winding 5 runs around the secondary winding, so that the secondary windings are in Figure 1 are not visible. The legs of the magnetic cores 9, surrounded by the secondary and primary windings 5, are arranged in a star shape around the axis of rotation 35 in a plane perpendicular to the axis of rotation 35, offset from each other by 120 degrees. One end of each primary winding 5 is connected to an electrode 7, which is arranged around a central section of the primary winding 5.

[0028] The carrier plate 33 of the carrier element 13 is arranged in a plane between a first spatial area in which the primary windings 5 ​​are arranged and a second spatial area in which the feedthrough contacts 11 are arranged.

[0029] The contact elements 15 are arranged on the carrier plate 33. Each contact element 15 is assigned a primary winding 5 and a feedthrough contact 11, which are electrically connected to each other by the contact element 15 in the first end position of the carrier element 13 and are galvanically isolated from each other in the second end position of the carrier element 13. The contact elements 15 of the in Figure 1 The voltage converter 1 shown below is described using the following: Figures 2 to 4 described in more detail.

[0030] A mechanism 37 for rotating the support element 13 and a terminal box 39 for the voltage converter 1 are arranged on the housing cover 19. The mechanism 37 includes a lever 41 with which the support element 13 can be manually rotated between its two end positions.

[0031] Figure 2 (FIG 2 ) shows a perspective view of the in Figure 1 shown voltage converter 1 in the area of ​​a contact element 15.

[0032] Figure 3 (FIG 3 ) and Figure 4 (FIG 4 ) show a contact element 15 of the in Figure 1 shown voltage converter 1, wherein Figure 3 a sectional view of the contact element 15 shows and Figure 4 a perspective view of contact element 15 is shown.

[0033] The contact element 15 comprises two roller contacts 43, 45. Each roller contact 43, 45 has a rolling bearing 47 with an electrically conductive outer ring 49. In the first end position of the carrier element 13, the outer ring 49 of the first roller contact 43 contacts the electrode 7 of the primary winding 5 associated with the contact element 15. In the first end position of the carrier element 13, the outer ring 49 of the second roller contact 45 contacts the contact surface 29 of the bushing contact 11 associated with the contact element 15. Furthermore, each roller contact 43, 45 has an electrically conductive holder 51 in which the rolling bearing 47 is arranged and which is electrically connected to the outer ring 49 of the rolling bearing 47 by a sliding contact 53. The sliding contact 53 is designed as a contact spring which is attached to the holder 51 by a screw connection 55 and is pre-tensioned against the outer ring 49.

[0034] Each rolling contact 43, 45 is resiliently mounted in an opening 59 of an electrically conductive base body 61 of the contact element 15 by a leaf spring element 57. The leaf spring element 57 also electrically connects the holder 51 of the rolling bearing 47 to the base body 61. The rolling contact 43, 45 is guided in the opening 59 by a guide 63, and the leaf spring element 57 extends outside the guide 63 from an opening base 65 of the opening 59 to the holder 51 of the rolling bearing 47. The guide 63 is fastened to the base body 61 by a screw connection 67.

[0035] The openings 59 of the base body 61 of the contact element 15 are each surrounded by a wall 69 of the base body 61 with a convex outer surface 71. The contact elements 15 are attached to the carrier plate 33 by screw connections 73.

[0036] Figure 5 (FIG 5Figure 1 schematically shows a rolling contact 75 of a contact element 15 of a second embodiment of a voltage converter 1. The rolling contact 75 has an electrically conductive ball 79 mounted in an electrically conductive sliding bearing 77, the sliding bearing 77 being shown in section. Apart from the design of the rolling contact 75, the second embodiment does not differ from the one shown in the Figures 1 to 4 The first embodiment of a voltage converter 1 shown. Each contact element 15 of the second embodiment thus has two roller contacts 75, which are analogous to the roller contacts 43, 45 of the one shown in the Figures 1 to 4 In the illustrated embodiment, each contact element 15 is resiliently mounted in an opening 59 of the base body 61.

[0037] Although the invention has been illustrated and described in detail by preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived by those skilled in the art without departing from the scope of protection of the invention. In other embodiments, the voltage converter 1 can, for example, instead of a star-shaped arrangement of the magnetic cores 9, have an arrangement of the magnetic cores 9 along the three sides of an equilateral triangle or a different number of magnetic cores 9 and / or primary windings 5.

Claims

1. Voltage converter (1), comprising - an encapsulating housing (3) having a bushing (21), - at least one primary winding (5), - for each primary winding (5) an electrode (7), which is electrically connected to an end of the primary winding (5), and an electrical bushing contact (11) spaced apart from the primary winding (5), - a carrier element (13) rotatable between a first end position and a second end position about an axis of rotation (35) and - for each primary winding (5) an electrically conductive contact element (15) arranged on the carrier element (13), to which the primary winding (5) and the associated bushing contact (11) are assigned and which electrically connects the electrode (7) of the primary winding (5) in the first end position of the carrier element (13) to the bushing contact (11) and in the second end position of the carrier element (13) galvanically separates it from the bushing contact (11), wherein in the encapsulating housing (3) each primary winding (5), each bushing contact (11), the carrier element (13) and each contact element (15) are arranged, wherein each bushing contact (11) is arranged on the bushing (21), characterized in that the contact element (15) has at least one rolling contact (43, 45, 75), via which the contact element (15) in the first end position of the carrier element (13) contacts the electrode (7) of the primary winding (5) or the bushing contact (11), wherein each rolling contact of a said contact element is resiliently mounted by at least one leaf spring element on a base body of the contact element, wherein each leaf spring element electrically connects the rolling contact resiliently mounted by the leaf spring element to the base body of the contact element.

2. Voltage converter (1) according to claim 1, wherein each contact element (15) has a first rolling contact (43, 75), which contacts the electrode (7) of the primary winding (5) assigned to the contact element (15) in the first end position of the carrier element (13), and a second rolling contact (45, 75), which contacts the bushing contact (11) assigned to the contact element (15) in the first end position of the carrier element (13).

3. Voltage converter (1) according to claim 1 or 2, wherein the at least one rolling contact (43, 45) has a rolling bearing (47) with an electrically conductive outer ring (49), which contacts the electrode (7) of the primary winding (5) assigned to the contact element (15) or the bushing contact (11) assigned to the contact element (15) in the first end position of the carrier element (13).

4. Voltage converter (1) according to claim 3, wherein each rolling contact (43, 45) having a rolling bearing (47) has an electrically conductive holder (51), in which the rolling bearing (47) is arranged and which is electrically connected to the outer ring (49) of the rolling bearing (47) by a sliding contact (53).

5. Voltage converter (1) according to one of the preceding claims, wherein the at least one rolling contact (75) has an electrically conductive ball (79) mounted in an electrically conductive sliding bearing (77), which contacts the electrode (7) of the primary winding (5) assigned to the contact element (15) or the bushing contact (11) assigned to the contact element (15) in the first end position of the carrier element (13).

6. Voltage converter (1) according to one of the preceding claims, wherein each rolling contact (43, 45, 75) of a contact element (15) is resiliently mounted on a base body (61) of the contact element (15).

7. Voltage converter (1) according to claim 6, wherein each rolling contact (43, 45, 75) is resiliently mounted in an opening (59) of the base body (61) of the contact element (15).

8. Voltage converter (1) according to one of the preceding claims, wherein the at least one primary winding is given by three primary windings (5), which are arranged spaced apart from one another around the axis of rotation (35) of the carrier element (13).

9. Voltage converter (1) according to claim 8, wherein the primary windings (5) are arranged offset from one another by 120 degrees around the axis of rotation (35) of the carrier element (13) and the carrier element (13) is rotatable by 60 degrees about the axis of rotation (35) between the two end positions.

10. Voltage converter (1) according to one of the preceding claims, wherein the carrier element (13) has a carrier plate (33), on which each contact element (15) is arranged, and a carrier shaft (31) connected to the carrier plate (33), through which the axis of rotation (35) runs.

11. Voltage converter (1) according to claim 10, wherein the carrier plate (33) is arranged in a plane between a first spatial region, in which each primary winding (5) is arranged, and a second spatial region, in which each bushing contact (11) is arranged.

12. Voltage converter (1) according to one of the preceding claims, wherein each bushing contact (11) has a convex contact surface (29), which is contacted by a rolling contact (43, 45, 75) in the first end position of the carrier element (13) .