DE102013107545A1 - load selector - Google Patents

Abstract

The present invention relates to a load selector (1) for performing switching from one winding tap to an adjacent winding tap. The load selector (1) is simple, inexpensive to manufacture and assemble while ensuring safe and reliable operation. For this purpose, the actuating arrangement (41) is constructed from a plurality of physically separate actuating elements (50) with control cams (51, 52).

Description

The present invention relates to a load selector. The load selector includes a diverter switch insert having a one-axis rotatable switching tube, the diverter switch insert comprising a first phase, a second phase, and a third phase. Each phase comprises at least one switching segment with at least two vacuum interrupters. Each of the vacuum interrupters is associated with an actuating lever, which carries a respective roller at a first end and interacts with a second end, each with a vacuum interrupter. An actuator assembly on an inner wall of the oil pan cooperates with the rollers of the actuating levers.

Such load selectors belong to on-load tap changers (in English "on-load tap changers", abbreviated OLTC) and are well known and commonly used in the prior art. They are used for uninterrupted switching between different winding taps of tapped transformers.

In general, on-load tap-changers are actuated by a motor drive when switching over. By the motor drive an output or input shaft is moved, which raises a power storage. If the energy storage fully wound, ie strained, he is unlatched, releases his energy abruptly and operated in the period of milliseconds (ms) a diverter switch insert, which performs doing a specific switching sequence during load switching. In this case, different switch contacts and resistor contacts are actuated in a specific time sequence. The switch contacts are used for direct connection of the respective winding tap with the load dissipation, the resistor contacts for short-term wiring, ie bridging means of one or more switching resistors. Advantageously, vacuum interrupters are used as switching elements for load switching. This is due to the fact that the use of vacuum interrupters for load switching prevents arcing in the oil and thus the oil contamination of the diverter switch oil, as for example in the German patents DE 195 10 809 C1 and DE 40 11 019 C1 as well as the German Offenlegungsschriften DE 42 31 353 A1 and DE 10 2007 004 530 A1 described.

Load selector of the type mentioned, as for example in the German patent DE 28 33 126 C2 described, serve to switch the taps of the control windings of these tapped transformers under load and thus compensate for voltage changes in the consumer targeted.

From the WO 2010/142680 A1 a load selector is known in the interior of which a switching shaft is arranged, are secured to the at least two switching contacts and a Ableitkontakt per phase. The actuation of the switching contacts via levers, which are pressed by cam rings, which are arranged in the interior of the load selector, in the direction of the switching shaft.

From the WO 2012/003863 A1 a load selector is known which consists of an insulating cylinder with contact elements. Inside the Lastwählers a switching shaft is arranged, on which at least one contact frame is fixed with switching contacts. Furthermore, a cam ring is arranged in the interior of the cylinder. The levers, which are mechanically connected on the one hand to the switching contacts and on the other hand with the cam ring, serve as actuating means for the switching contacts.

A disadvantage of the known from the prior art cam rings is their size. Here is a lot of material needed in the production of these cam rings. Since the cam rings are used as a load dissipation, they must be made of electrically conductive material, such as copper. Against the background of rising raw material prices such large cam rings are very expensive. Since the switching sequences are also controlled in a targeted manner by the cam rings and the smallest units of time are important, tight manufacturing tolerances must be maintained. The production of such large parts with extreme accuracy is particularly expensive and time-consuming.

The object of the invention is therefore to provide a load selector that is simple in construction, cost-effective to manufacture and assemble while ensuring safe and reliable operation.

This object is achieved by a load selector with the features of claim 1.

The load selector according to the invention for carrying out switching from one winding tapping to an adjacent winding tapping comprises a diverter switch insert with an axis-rotatable switching tube which is arranged in an oil vessel. The diverter switch insert includes a first phase, a second phase, and a third phase. Each phase comprises at least one switching segment with at least two vacuum interrupters. Each vacuum interrupter is associated with an actuating lever, each carrying a roller at a first end and cooperating with a second end operatively connected to a vacuum interrupter. An actuator assembly on an inner wall of the oil pan cooperates with the rollers of the actuating levers. The Actuator assembly includes at least two separate actuators that are physically separated from each other. Each actuator has an upper cam and a lower cam formed, with each cooperating a role of an actuating lever.

In one embodiment, an actuation of a first vacuum interrupter takes place via the upper control cam and its associated actuating lever, and an actuation of a second vacuum interrupter via the lower control curve and the associated actuating lever. Each actuator carries at least one stage contact and cooperates with a diverting / guiding ring. The at least one step contact holds at least one holding element a respective actuating element on the inner wall of the oil vessel.

According to a preferred embodiment, the discharge / guide ring is conductively connected in the first phase with an electrical connection element, so that the discharge / guide ring is a discharge ring. The electrical connection element is guided through the oil vessel wall. The electrical connection element associated holding element and at least one further holding element are connected to the oil vessel so as to additionally support the actuating element on the inner wall of the oil vessel. The diverter / guide ring is connected in the other two phases via at least two retaining elements with the oil vessel, so that the respective actuating element is additionally supported on the inner wall of the oil vessel.

At the switching segments of the individual phases guide rollers may be provided, which attach to an upper side and on a lower side of the diverting / guide ring and thus provide the necessary guidance. In the event that the load selector is designed as a star point load selector, the second and the third phase lead-off / guide rings only have the function of a guide ring and can therefore be made of a non-electrically conductive material.

The diverter / guide ring and the at least one stage contact are arranged between the upper control cam and the lower control curve of each actuating element.

According to one embodiment, each actuating element has at least one bore with at least one positioning groove for fastening a stepped contact, wherein the stepped contact has at least one web corresponding to the positioning groove. Likewise, each actuator at least one breakthrough with a stop for attachment of the electrical connection element with holding element or the at least one further holding element for the diverter.

The actuating element is preferably made of a dimensionally stable plastic, wherein in the manufacturing process already the upper control cam and the lower control cam are introduced by appropriate forming, in particular without additional machining.

An advantage of the load selector, with an actuator assembly consisting of a plurality of physically separate actuators, is the ease of manufacture and the lower manufacturing costs through low cost materials. This is achieved by the material used, namely plastic instead of metal. Since the actuators are not connected continuously, in addition, less material is used as in a continuous rotating actuator assembly. In addition, the risk of distortion in the separate actuators of the actuator assembly is completely excluded, so that the Committee is significantly reduced.

Due to the fact that the individual actuating elements are smaller than a one-piece actuating arrangement, it is possible to produce them precisely and quickly, for example by injection molding. The implementation of simple changes to individual actuators is not necessary so that manufacturing tolerances can be easily met.

In the following, the invention and its advantages will be described in more detail with reference to the accompanying drawings. Show it:

1 a perspective view of a three-phase load selector;

2 a sectional view of the load selector along in 1 drawn section line AA;

3 a perspective view of the diverter switch insert of the three-phase load selector after 1 , wherein the three switching segments attached to the switching tube and the massive element can be seen;

4 another perspective view of the diverter switch insert of the three-phase load selector after 1 showing the three resistor assemblies attached to the switch tube and the high-mass element;

5 a section of a rotated perspective sectional view along the section line BB 2 with a switching segment;

6 a section of a sectional view along the section line BB 2 with a switching segment with vacuum interrupters, but without representation of the switching tube;

7 an actuator of the load selector according to the invention;

8th a step contact with at least one web; and

9 a perspective sectional view along the section line CC 6 ,

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are only examples of how the load selector according to the invention can be and thus do not constitute a final limitation of the invention.

1 shows a perspective view of a three-phase on-load tap changer or load selector according to the invention 1 , The load selector 1 has a drive 3 , such as an electric motor, with a transmission 5 on, which raises a power storage, not shown. If the energy storage fully wound up, ie strained, he is unlatched, releases his energy abruptly and operates a switching tube 15 a diverter switch insert 14 , The rotating switching tube 15 is in an oil container 18 supported. The oil vessel 18 is upwards with a lid 19 closed and also carries a floor 21 ,

The load selector according to the invention 1 has a first phase L1, a second phase L2 and a third phase L3, one above the other in the oil vessel 18 are arranged. Over the three phases L1, L2, L3 sits a selection 37 , In the view shown here are electrical connection elements 38 for preselector contacts on the oil tank wall 17 of the oil container 18 intended. Electrical connection elements 39 for step contacts 392 (please refer 5 . 6 . 8th . 9 ) of the three phases L1, L2, L3 are also doing so on the load selector 1 arranged that they pass through the oil wall 17 of the oil container 18 to grab.

2 shows a sectional view taken along the line AA 1 of the load selector 1 , wherein a plan view of the first phase L1 is shown. On an inner wall 20 of the oil container 18 are more for the second phase L2 to the contour of the inner wall 20 of the oil container 18 adapted actuators 50 that is an actuator assembly 41 represent, arranged. Electrical connection elements 39 for the tap contacts 392 (please refer 5 . 6 . 8th and 9 ) engage through the corresponding actuators 50 and through the oil wall 17 of the oil container 18 to its outer wall 16 , screen caps 30 on the outside wall 16 of the oil container 18 hold the on the inner wall 20 of the oil container 18 arranged actuators 50 , For this purpose, the electrical connection elements act 39 for the tap contacts, not shown here 392 and the electrical connection elements 68 for the discharge contact, not shown here 391 over the shield caps 30 with the holding elements (not shown here) of the tap contacts 392 and the holding element for the discharge contact of the first phase L1 together, so that the actuating elements 50 on the inner wall 20 of the oil container 18 are held. The shield caps 30 lie on the outside wall 16 of the oil container 18 on. Each of the actuators 50 has at least two cams 51 . 52 (please refer 5 . 6 and 7 ) formed with corresponding and with rollers 43 provided operating levers 45 of the switching segment 25 the corresponding phase L1, L2, L3 cooperate.

The switching tube 15 carries in each phase L1, L2, L3 a bracket 40 on which a massive element 36 , the respective resistor arrangement 27 and the respective switching segment 25 are mounted. The switching segment 25 is mounted in such a way that the rollers 43 the operating lever 45 with the corresponding cams 51 . 52 the actuators 50 interact.

3 and 4 show various perspective views of the diverter switch insert 14 of the three-phase load selector 1 to 1 , On the switching tube 15 the diverter switch insert 14 are three switching segments 25 attached, so that the load selector 1 is divided into the three phases L1, L2, L3. In addition to the switching segments 25 are on the switching tube 15 as well as resistor arrangements 27 attached to the individual phases L1, L2, L3 of the load selector 1 assigned. By turning the switching tube 15 can have moving contacts 29S for step contacts or movable contacts 29A be connected directly for Ableitkontakte, the movable contacts 29S . 29A with corresponding Ableitkontakten not shown here 391 or the step contacts, also not shown 392 interact (see 5 or 6 ). A predetermined switching sequence is by means of the control curves 51 . 52 (see also 5 . 6 and 7 ) realized in which a plurality of vacuum interrupters 33 . 34 (please refer 6 ) in the individual switching segments 25 be opened or closed.

According to the invention is a flywheel 35 on the switching tube 15 assembled. In addition, that contributes switching tube 15 a massive element 36 as described below.

5 shows a section of the rotated perspective sectional view of the line BB 2 with a switching segment 25 , where in this view the vacuum interrupters 33 . 34 not to be seen (see 6 ). The switching segment 25 is with the switching tube 15 mechanically non-rotatably connected. The actuators 50 are, as shown, on the inner wall 20 of the oil container 18 arranged and result in the entirety of the actuator assembly 41 , Each actuator 50 has an upper cam 51 and a lower cam 52 on. The actuator 50 is preferably formed from a plastic and is preferably produced by forming or by injection molding without mechanical processing.

At the in 5 The figure shows the first phase L1 is shown. A discharge / guide ring 391 , which is designed as a discharge contact, is inside the load selector 1 arranged. This is with an electrical connection element 68 (please refer 9 ) connected. Each actuator 50 is about the at least one stage contact 392 in cooperation with the respective holding elements 31 on the inner wall 20 of the oil container 18 assembled. The diverter ring 391 is about holding elements 31 on the inner wall 20 of the oil container 18 through the actuator assembly 41 from the multiple actuators 50 attached. Every stage contact 392 is from the moving contacts 29S for the tap contacts 392 of the switching segment 25 alternately contacted depending on the selected level. Outside the oil container 18 are electrical connection elements 39 the tap contacts 392 provided so that an electrical line (not shown), which leads to a step winding, can be attached thereto.

Both the discharge / guide ring 391 as well as the tap contacts 392 are in this example between the upper cam 51 and the lower cam 52 the actuators 50 arranged.

6 shows a section of the sectional view along the line BB 2 , in which the switch segment 25 associated vacuum interrupters 33 . 34 can be seen. Each vacuum interrupter 33 . 34 is an operating lever 45 assigned. A second end each 45b of the operating lever 45 is with the vacuum interrupters 33 . 34 connected. At the first end 45a of each operating lever 45 is each a role 43 arranged. By rotation of the switching tube 15 and the associated with this switching segments 25 become the upper control curve 51 or lower cam 52 by a role 43 an actuating lever 45 traversed and by this interaction are the vacuum interrupters 33 . 34 of the switching segment 25 operated in the predetermined manner.

7 shows a perspective view of an actuating element 50 , Each of the actuators used in the invention 50 is identical. The actuator 50 has at least one hole 60 for the installation and the implementation of electrical connection elements 39 the tap contacts 392 (please refer 5 . 6 ) on. At every drilling 60 is in each case at least one positioning groove 61 arranged. This corresponds to one at the respective stage contact 392 trained footbridge 64 (please refer 8th ). The jetty 64 prevents the tap contact 392 twisted during operation. Furthermore, the bridge facilitates 64 the exact positioning of the step contacts 392 on the actuator 50 , In a preferred embodiment, each actuator is 50 over two stages contacts 392 , each with a retaining element 31 and an electrical connection element 39 of the step contact 392 dispose of (see 7 ), with the oil vessel 18 connected.

Furthermore, each actuator 50 at least one breakthrough 62 with one stop each 63 on. The breakthroughs 62 serve to carry out a holding element 31 or a holding element 31 with an electrical connection elements 68 for the discharge / guide ring 391 , via which the diverting / guiding ring 391 is fixed. The stop 63 is formed such that the electrical connection element 68 with retaining element 31 (please refer 9 ) or holding elements 31 (please refer 5 and 6 ) alone correspond to such that they can not be twisted when mounting.

8th shows a tap contact 392 with the holding element 31 , the electrical connection element 39 as well as with at least one footbridge 64 , This corresponds to the positioning groove 61 (please refer 7 ) and ensures that the tap contact 392 is aligned during assembly and can not be rotated during operation.

9 shows a sectional view along the section line CC 6 , The preferred embodiment of the first phase L1 of the load selector 1 has a discharge / guide ring 391 on, the electrically conductive with the electrical connection element 68 for the diverter ring 391 connected is. The holding element 31 with the electrical connection element 68 extends through the breakthrough 62 of the actuating element 50 outward. Furthermore, the discharge / guide ring 391 by means of at least two holding elements 31 , in turn, through the breakthroughs 62 further actuators 50 extend, inside the oil container 18 fixed. With a load selector 1 with five actuators 50 thus not all breakthroughs 62 the actuators 50 used. The remaining breakthroughs 62 stay free. The actuators 50 are each via the tap contacts 392 in cooperation with the holding elements 31 , here two each per actuator 50 , with the oil container 18 connected. By two stage contacts 392 will ensure that the actuators 50 are positioned clearly and secure against rotation.

LIST OF REFERENCE NUMBERS

1

On-load tap-changer, load selector

3

drive

5

transmission

14

Diverter switch insert

15

switching tube

16

Outer wall of the oil vessel

17

Oil vessel wall

18

oil vessel

19

cover

20

Inner wall of the oil vessel

21

ground

25

switching segment

27

resistor arrangement

29A

movable contact for discharge contact

29S

mobile contact for step contact

30

canopy

31

retaining element

33

Vacuum interrupter

34

Vacuum interrupter

35

Inertia

36

massive element

37

selection

38

electrical connection element for preselector contact

39

electrical connection element for step contact

391

Discharge contact, discharge / guide ring

392

stages Contact

40

bracket

41

actuator assembly

43

role

45

actuating lever

45a

first end

45b

second end

50

actuator

51

upper control curve

52

lower cam

53

electrically conductive connecting element

54

screw

55

electrical connection

60

drilling

61

positioning

62

breakthrough

63

attack

64

web

65

Inner surface of the actuating element

68

electrical connection element for discharge contact / discharge ring

A-A

cut Line

B-B

intersection

C-C

cut Line

L1

first phase

L2

second phase

L3

third phase

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19510809 C1 [0003]
• DE 4011019 C1 [0003]
• DE 4231353 A1 [0003]
• DE 102007004530 A1 [0003]
• DE 2833126 C2 [0004]
• WO 2010/142680 A1 [0005]
• WO 2012/003863 A1 [0006]

Claims (10)

Load selector ( 1 ) with a diverter switch insert ( 14 ) with a about an axis (A) rotatable switching tube ( 15 ) stored in an oil container ( 18 ), wherein the diverter switch insert ( 14 ) comprises a first phase (L1), a second phase (L2) and a third phase (L3), each phase (L1, L2, L3) comprises at least one switching segment (L1) 25 ) with at least two vacuum interrupters ( 33 . 34 ) and each vacuum interrupter ( 33 . 34 ) an actuating lever ( 45 ) associated with a first end ( 45a ) each have a role ( 43 ) and with a second end ( 45b ), each with a vacuum interrupter ( 33 . 34 ) cooperates; and an actuating arrangement ( 41 ) on an inner wall ( 20 ) of the oil vessel ( 18 ), with the roles ( 43 ) the operating lever ( 45 ) cooperates; characterized in that the actuating arrangement ( 41 ) at least two separate actuators ( 50 ); and that each actuator ( 50 ) an upper control cam ( 51 ) and a lower control cam ( 52 ), with one roll each ( 43 ) of an actuating lever ( 45 ) cooperates. Load selector ( 1 ) according to claim 1, wherein via the upper control cam ( 51 ) and its associated operating lever ( 45 ) an actuation of a first vacuum interrupter tube ( 33 ) and the lower control cam ( 52 ) and its associated operating lever ( 45 ) actuation of a second vacuum interrupter tube ( 34 ) he follows. Load selector ( 1 ) according to one of the preceding claims, wherein each actuating element ( 50 ) at least one stage contact ( 392 ) and with a discharge / guide ring ( 391 ) cooperates. Load selector ( 1 ) according to claim 3, wherein the at least one stage contact ( 392 ) with at least one retaining element ( 31 ) the respective actuating element ( 50 ) on the inner wall ( 20 ) of the oil vessel ( 18 ) holds. Load selector ( 1 ) according to one of claims 3 to 4, wherein the discharge / guide ring ( 391 ) in the first phase (L1) with an electrical connection element ( 68 ) is conductively connected, wherein the electrical connection element ( 68 ) through the oil vessel wall ( 17 ) is guided and wherein the electrical connection element ( 68 ) associated retaining element ( 31 ) and at least one further retaining element ( 31 ) with the oil vessel ( 18 ) are connected to the actuating element ( 50 ) in addition to the inner wall ( 20 ) of the oil vessel ( 18 ). Load selector ( 1 ) according to one of claims 3 to 5, wherein the discharge / guide ring ( 391 ) in the two remaining phases (L2, L3) via at least two holding elements ( 31 ) with the oil vessel ( 18 ), so that the respective actuating element ( 50 ) in addition to the inner wall ( 20 ) of the oil vessel ( 18 ) is held. Load selector ( 1 ) according to one of claims 3 to 6, wherein the discharge / guide ring ( 391 ) and the at least one stage contact ( 392 ) between the upper control cam ( 51 ) and the lower cam ( 52 ) of each actuator ( 50 ) are arranged. Load selector ( 1 ) according to one of claims 3 to 7, wherein each actuating element ( 50 ) at least one bore ( 60 ) with at least one positioning groove ( 61 ) for fixing a step contact ( 392 ) and wherein the step contact ( 392 ) at least one to the positioning groove ( 61 ) corresponding bridge ( 64 ) having. Load selector ( 1 ) according to one of claims 3 to 7, wherein each actuating element ( 50 ) at least one breakthrough ( 62 ) with a stop ( 63 ) for fastening the electrical connection element ( 68 ) with holding element ( 31 ) or the at least one further holding element ( 31 ) for the discharge ring ( 391 ) having. Load selector ( 1 ) according to one of the preceding claims, wherein each actuating element ( 50 ) is made of a dimensionally stable plastic and wherein in the manufacturing process by forming the upper control cam ( 51 ) and the lower control cam ( 52 ) can be formed without additional machining.

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