Load tap changer and on-load tap changer for an on-load tap changer

Abstract

The invention relates to a load transfer switch (1) for a load tap changer (2), comprising at least one vacuum interrupter (30), a handling element (50) which is mechanically connected to the vacuum interrupter (30) on a first end (51) and has a roller (53) on a second end (52), a handling body (10) which has a base body (11) and at least one cam (20), wherein the vacuum interrupter (30) is handled via the handling element (50) by the roller (53) being driven over the handling body (10), at least one part (21) of the cam (20) having a higher strength than the base body (11).

Description

TECHNICAL FIELD

[0001] The invention relates to a load transfer switch for a load tap changer and to a load tap changer having such a load transfer switch. BACKGROUND

[0002] Load tap changers are used to implement a transfer in a regulatable transformer. The transfer takes place by mechanical manipulation of different switches. The requirements for the manipulation mechanism increase as the load rises, i.e. higher currents and voltages. SUMMARY

[0003] It is therefore the task of the invention to give an improved load transfer switch for a load tap changer, which withstands high mechanical loads at high currents and voltages and is reliable and safe here.

[0004] It is also the task of the invention to give a load tap changer, which withstands high mechanical loads at high currents and voltages and is reliable and safe here.

[0005] The improved design is based on the idea that a part of the cam or the entire cam of the manipulation element is constructed of a material that is harder than the material of the base body. Since a very high force has to be applied for opening the vacuum switch tube at high currents, there is a risk that the cam breaks due to the roller driving over it. Here, the maximum load occurs in the part of the cam that is responsible for "breaking" the vacuum switch tube, i.e. the so-called opening side. For this reason, at least a part of the cam is constructed of metal, in particular steel or quenched and tempered steel. This part is then at least as hard as the roller and has a higher or the same strength. In order to maintain the insulation clearance in the interior of the load transfer switch, the base body of the manipulation body is constructed of an insulating material, for example plastic or glass fiber reinforced plastic, and a part of the cam or the entire cam is constructed of metal, in particular steel or quenched and tempered steel.

[0006] According to the improved design, a load transfer switch for a load tap changer is given, which comprises at least one vacuum switch tube. Furthermore, the load transfer switch comprises a manipulation element, which is mechanically connected to the vacuum switch tube on a first end and has a roller on a second end, and a manipulation body, which has a base body and at least one cam. The vacuum switch tube is manipulated via the manipulation element by driving over the manipulation body with the roller. At least a part of the cam has a higher strength than the base body.

[0007] The actuating element can be configured as a simple connection between the movable contact and the roller. Furthermore, the actuating element can be configured as a curved lever. The task of the actuating element is to transmit the force acting on the roller to the movable contact of the vacuum interrupter. The actuating body can be configured in a disc-shaped, cylindrical or rod-shaped manner. The cam can be provided on the outside, that is to say on the circumference, or on the upper or lower side. In order to drive the actuating body, the actuating body can be rotated, deflected or moved about one or more axes. Furthermore, in order to drive the cam, the actuating element can be rotated, deflected or moved.

[0008] According to at least one embodiment, the vacuum interrupter is opened by the driving of the at least one part of the cam. According to at least one embodiment, the at least one part of the cam opening the vacuum interrupter is an opening side. According to at least one embodiment, the base body is composed of an insulating material, for example plastic or glass fiber reinforced plastic. According to at least one embodiment, the at least one part of the cam or the entire cam is composed of metal, in particular steel or quenched and tempered steel.

[0009] According to at least one embodiment, the actuating body has a base body, the base body having four cams, the cams having four vacuum interrupters, each vacuum interrupter having one actuating element, the four vacuum interrupters being arranged in a circular manner around the actuating body. The load transfer switch can be configured in a single-phase, two-phase or three-phase manner, such that for each phase six or fewer vacuum interrupters are provided. The vacuum interrupters of one phase are arranged side by side in one sector.

[0010] According to the improved design, a load tap changer is given, the load tap changer comprising at least one load transfer switch according to the improved design. BRIEF DESCRIPTION OF DRAWINGS

[0011] The application is explained in detail below with the aid of exemplary embodiments with reference to the drawings. Functionally identical or identically acting parts can be provided with the same reference signs. Identical parts or parts having the same function can only be explained with respect to their first occurrence in the figures. The explanation does not necessarily have to be repeated in the following figures.

[0012] In the drawings:

[0013] Figure 1 A schematic diagram of an adjustable transformer with a load tap changer comprising a load transfer switch and a selector is shown;

[0014] Figure 2 A load transfer switch according to the application is shown;

[0015] Figure 3 An actuating body of a load transfer switch according to the application is shown. Detailed Implementation

[0016] Figure 1 An adjustable transformer 3 with an on-load tap changer 2 is shown, the on-load tap changer having a load transfer switch 1 and a selector 4. The on-load tap changer 2 is driven by a motor 5.

[0017] Figure 2 The interior of a load changeover switch 1 according to the invention is shown. An operating body 10, having a base 11 and a plurality of cams 20, is disposed at the center of the load changeover switch 1. The operating body 10 is mechanically connected to a drive shaft 19 without relative rotation. The drive shaft 19 is connected to and operated by a spring energy storage device or motor drive 5 (not shown here). Here, the drive shaft 19 and therefore the operating body 10 rotate about axis A during operation. Here, the drive shaft 19 rotates in the same direction or rotates back and forth at a fixed angle, that is, forward and backward. Vacuum switch tubes 30 are fixedly arranged around the operating body 10. Typically, multiple vacuum switch tubes are arranged around the operating body with corresponding operating mechanical axes, for example, arranged in a circle.

[0018] The vacuum switch tube 30 has a movable contact 31 connected to an actuating element 50. In this embodiment, the actuating element 50 is configured as a rocker arm. The actuating element 50 is connected at its first end 51 to the movable contact 31 of the vacuum switch tube 30. In the embodiment shown here, the first end 51 is forked. The actuating element 50 has a roller 53 at its second end 52. Each of the vacuum switch tubes in the load transfer switch has an actuating element, and each actuating element has a roller.

[0019] All components of the load transfer switch 1 are housed in a housing not shown here. The housing may be constructed, for example, in a cylindrical or box-like shape.

[0020] Figure 3 A detailed view of the control body 10 is shown. The control body 10 has a base 11 and a plurality of cams 20. Here, the cams 20 are disposed on the circumferential surface 14 of the control body 10, which is constructed in a substantially disc-shaped or cylindrical manner. In the embodiment shown here, the control body 10 has a first control profile 12 and a second control profile 13 disposed directly below it. The two control profiles 12, 13 are disposed on the circumferential surface 14 and extend over the entire perimeter. It is also possible for one or more control profiles to be arranged on the upper side 15 or the lower side 16 of the control body 10. The cams 20 are integral parts of the control profiles 12, 13.

[0021] In the embodiment shown here, a portion 21 of the cam 20 is composed of a material different from the base body 11. This portion 21 of the cam 20 is the opening side. This portion 21 is connected form-lockingly and / or force-lockingly to the base body 11. This is achieved by gluing and / or riveting and / or screwing. Furthermore, this portion 21 can be embedded in the recess 17 in the base body 11. This portion 21 is preferably composed of metal, in particular steel or quenched and tempered steel. The base body 11 is preferably composed of an insulating material, for example plastic or glass-fiber reinforced plastic.

[0022] In order to actuate, that is to say in order to open or close the vacuum interrupter 30, the roller 53 rides over the actuating contour 12, 13 of the actuating body 10 on the second end 52 of the actuating element 50. The vacuum interrupter 30 is opened when riding over the opening side, that is to say the portion 21, of the cam 20. Thereafter, the vacuum interrupter 30 remains open by further riding over of the cam 20. In the example shown here, the cam 20 presses onto the roller 53 of the actuating element 50. Since the actuating element is configured as a rocker lever, the rocker lever is deflected about a deflection axis, and the first end 51 of the actuating element 50 pulls on the movable contact 31 of the vacuum interrupter 30 and opens this vacuum interrupter. In order to close the vacuum interrupter 30, the actuating body 10 is rotated in the opposite direction to the opening. The vacuum interrupter 50 is closed when riding over the opening side.

[0023] Preferably, the at least one portion 21 of the cam 20 is composed of a material having a higher strength than the roller 53 or the same strength as the roller.

[0024] In the example shown here, the actuating body 10 has one base body 11 and two superimposed actuating contours 12, 13 arranged on the peripheral surface 14. The first actuating contour 12 has two cams 20 for actuating two vacuum interrupters 30. Furthermore, the second actuating contour 13 has two cams 20 for actuating two further vacuum interrupters 30. A portion 21 of each cam 20 has a higher strength than the base body 11. This portion 21 is always the opening side 22, by means of which the corresponding vacuum interrupter 30 is opened by riding over by the roller 53. The respective cams 20 of the corresponding actuating contour can be moved relative to one another.

[0025] List of reference signs

[0026] 1 load changeover switch

[0027] 2 on-load tap changer

[0028] 3 adjustable transformer

[0029] 4 selector

[0030] 10 actuating body

[0031] 11 base

[0032] 12 first actuating contour

[0033] 13 second actuating contour

[0034] 14 peripheral surface

[0035] 15 upper side of the actuating body

[0036] 16 lower side of the actuating body

[0037] 17 recess

[0038] 19 drive shaft

[0039] 20 cam

[0040] 21 part of the cam

[0041] 22 opening side

[0042] 30 vacuum interrupter

[0043] 31 movable contact

[0044] 50 actuating element

[0045] 51 first end

[0046] 52 second end

[0047] 53 roller

Claims

1. Load transfer switch (1) for a load tap changer (2), the load transfer switch (1) comprising: - at least one vacuum interrupter (30), - a handling element (50) which is mechanically connected with the vacuum interrupter (30) on a first end (51) and which has a roller (53) on a second end (52), - a handling body (10) which has a base body (11) and which has at least one cam (20), wherein - the vacuum interrupter (30) is handled via the handling element (50) by a ride over of the roller (53) over the handling body (10), - at least one portion (21) of the cam (20) has a higher strength than the base body (11).

2. Load transfer switch (1) according to claim 1, wherein - the ride over of the at least one portion (21) of the cam (20) opens the vacuum interrupter (30).

3. Load transfer switch (1) according to claim 1 or 2, wherein - the at least one portion (21) of the cam (20) which opens the vacuum interrupter (30) is an opening flank (22).

4. Load transfer switch (1) according to claim 1 or 2, wherein - the base body (11) consists of an insulating material.

5. Load transfer switch (1) according to claim 1 or 2, wherein - the at least one portion (21) of the cam (20) consists of a metal.

6. Load transfer switch (1) according to claim 1 or 2, wherein - the handling body (10) has one base body (11) and four cams (20), - four vacuum interrupters (30) are provided, each of the vacuum interrupters having one handling element (50), - the four vacuum interrupters (30) are arranged circularly around the handling body (10).

7. Load tap changer having a load transfer switch according to any one of claims 1 to 6.

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