EP4264650A1

EP4264650A1 - Switching module, and on-load tap changer comprising a switching module

Info

Publication number: EP4264650A1
Application number: EP21830987.0A
Authority: EP
Inventors: Toni Hottner; Robert Hiltner; Sebastian Rehkopf; Max Weidinger
Original assignee: Maschinenfabrik Reinhausen GmbH; Maschinenfabrik Reinhausen Gebrueder Scheubeck GmbH and Co KG
Current assignee: Maschinenfabrik Reinhausen GmbH; Scheubeck GmbH and Co
Priority date: 2021-01-07
Filing date: 2021-12-07
Publication date: 2023-10-25
Also published as: CN116783676A; WO2022148583A1; DE102021100145B3

Abstract

The invention relates to a switching module (10) for an on-load tap changer (20) for switching between winding taps (N1, …NJ, …, NN) of a tapped transformer (1) without any interruption, comprising: a selector unit (30) for powerlessly preselecting a designated winding tap (NJ); a load transfer switch unit (40) for actually transferring a load from the previous winding tap (NJ-1) to the preselected winding tap (NJ); a plate (50), on which the selector unit (30) and the load transfer switch unit (40) are arranged; wherein the load transfer switch unit (40) is arranged on a separate cartridge (60), which is releasably connected to the plate (50).

Description

SWITCHING MODULE AND ON-LOAD TAP SWITCH WITH SWITCHING MODULE

The invention relates to a switching module for an on-load tap changer for uninterrupted switching between winding taps of a tapped transformer and an on-load tap changer with such a switching module.

On-load tap changers enable the transformation ratio of transformers to be changed under load and are well known from the prior art. They usually have a diverter switch and a selector. For uninterrupted switching, the diverter switch is equipped with switching means, for example vacuum switching tubes, and transition resistors, which are arranged in a cylindrical vessel filled with oil. The voter is usually located below the Lastumschal tervascular and builds up from a variety of rods arranged in a circle. Contacts are arranged in different levels on these rods, which serve as connections for a control winding. Inside the selector, two selector arms are attached to a switching column. These make contact with the contacts on the rods. Diverter switch and selector are connected to each other via a gear. The motor-drive unit is located on the outside of the step-up transformer and is connected to the on-load tap-changer via a linkage.

In another construction of on-load tap changers, the so-called load selector, which differs in design from the on-load tap changers described in the previous paragraph but is also known, the select and switch functions are combined in one switch. This means that the selector and diverter switch are not spatially separated from each other, but are arranged in a common oil tank.

For both types of construction, the diverter switch or the load selector can be removed from the oil compartment for repair or maintenance work to be carried out. This he follows from above via a cover of the transformer housing.

In the meantime, in addition to the two designs described, there are also new designs of tap changers that have a fundamentally different design without an oil tank and therefore require a new approach to maintenance or repairs.

It is therefore an object of the present invention to provide a concept for repair and maintenance work on on-load tap changers and/or assemblies of on-load tap changers without an oil tank, which enables quick and easy replacement of on-load tap changer assemblies relevant to service or in need of repair. This object is solved by the respective subject matter of the independent claims. Further embodiments are subject of the dependent claims.

According to a first aspect of the improved concept, a switching module for an on-load tap changer for uninterrupted switching between winding taps of a tapped transformer is specified.

The switching module includes a selector unit for power-free pre-selection to a selected winding tap, a diverter switch unit for the actual diverter switch from the previous winding tap to the preselected winding tap and a plate on which the selector unit and the diverter switch unit are arranged.

In this case, the diverter switch unit is arranged on a separate cassette which is detachably connected to the plate.

The on-load tap-changer's diverter switch unit is an assembly that determines the switching capacity, i.e. the limited number of possible on-load tap-changer switching operations to be carried out, and is therefore particularly relevant to service. By arranging the switching means of the diverter switch on a separate, detachable unit, this can be easily replaced together with the switching means without having to carry out conversion or expansion measures on the tap changer.

The plate and the cassette can be designed in any way, example, as a plate-shaped injection molded part. The plate and the cassette can be made of plastic, for example thermoplastic or glass-reinforced plastic, or any other electrically insulating material.

According to a preferred embodiment, the diverter switch unit comprises at least one vacuum interrupter and/or at least one electronic power switching element and/or at least one mechanical switching element, which can be configured as a bridge switch, for example. The power electronic switching means can be designed as IGBTs and/or thyristors, for example.

The bridge switch can be designed in any way, for example as a rotary switch, slide switch or toggle switch. The bridge switch can be actuated by linear or rotational movement. The selector unit can be designed in any way and can have, for example, one or more movable selector contacts. A moveable selector contact can be designed in any way, for example as a contact finger that is moved radially. The movable selector contacts can also be actuated in any desired manner, for example via a Geneva wheel or a gear wheel. Wei terhin has the voter on several fixed contacts that can be connected to the winding taps of the stepped transformer. These can be arranged in any way on the plate, such that they can be contacted by the movable selector contact or multiple movable selector contacts. For example, the fixed contacts are arranged radially on the disk.

According to another embodiment, the cassette has a first side and a second side opposite to the first side. The at least one vacuum interrupter and/or the at least one electronic switching element are arranged on the first side. The at least one mechanical switching element is arranged on the second side.

According to a further embodiment, the plate has a recess with an open side, which comprises guide means on at least two inner walls, via which at least two side walls of the cassette can be inserted into the recess, such that the cassette is secured in the inserted state and flush with the plate.

The guiding means can be designed in any way, for example as a groove in connection with a guide rail and/or rollers.

A handle is preferably provided on the cassette for inserting and removing the cassette.

The cassette can be fixed in the recess of the plate with suitable means. For example, this can be done with a bolt that can be pushed both through the cassette and through the plate and/or with a different locking mechanism.

According to a further embodiment, the switching module has at least one electrical interface via which a first line, which is assigned to the cassette, and a second line, which is assigned to the plate, can be connected to one another. Assigned here specifically means remaining on the plate or on the cassette when the cassette is pulled out. The electrical interface can be designed in any way.

According to one embodiment, the electrical interface is designed as a screw connection.

According to a further embodiment, the electrical interface is designed as a contact system that includes a contact bridge, a first plug contact that is assigned to the cassette, and a second plug contact that is assigned to the plate. The first plug contact is detachably connected to the contact bridge. In particular, the first plug-in contact can be inserted and/or pushed into the contact bridge and the contact bridge is arranged on the plate.

The contact bridge can be designed in any way. For example, the contact bridge can consist of two fixed contacts, which are spaced apart and arranged opposite one another, such that the plug-in contacts can be inserted and/or pushed in between the fixed contacts. The fixed contacts can be held in position by means of a guide pin, for example, and pressed together by means of spring force and against the plug-in contacts used, such that the fixed contacts are electrically bridged and electrically connected to one another.

According to a second aspect of the improved concept, an on-load tap changer for uninterrupted switching between winding taps of a stepped transformer is specified. The on-load tap changer includes at least one switching module that is designed according to the first aspect of the improved concept.

According to a preferred embodiment, the on-load tap changer has a second and third switching module for a second and third phase of the tapped transformer that is to be regulated, which switching module is designed according to the first aspect of the improved concept.

The invention is explained in detail below using exemplary embodiments with reference to the drawings. Components that are identical or functionally identical or have an identical effect may be given identical reference numbers. Identical components or components having an identical function may only be explained with respect to the figure in which they first appear. The explanation is not necessarily repeated in subsequent figures. The figures only represent exemplary embodiments of the invention, but without restricting the invention to the exemplary embodiments illustrated. Show it

FIG. 1 shows an exemplary embodiment of an on-load tap changer in a schematic representation;

FIG. 2 shows an exemplary embodiment of a switching module in a perspective representation according to the improved concept;

FIG. 3 shows a detailed view of an exemplary embodiment of the switching module according to the improved concept;

FIG. 4 shows a detailed view of an exemplary embodiment of the cassette of the switching module in a perspective representation according to the improved concept;

FIG. 5 shows a further detailed view of the cassette from FIG. 4 according to the improved concept;

FIG. 6 shows a detailed view of a further exemplary embodiment of the cassette of the switching module in a perspective representation according to the improved concept;

FIG. 7 shows a further detailed view of the cassette from FIG. 6 according to the improved concept;

FIG. 8 shows a further detailed view of the switching module according to the embodiment from FIGS. 6 and 7 according to the improved concept;

FIG. 9 shows an exemplary embodiment of an on-load tap changer with a switching module in a perspective representation according to the improved concept.

In Figure 1, an exemplary embodiment of an on-load tap changer 20 for a tapped transformer 1 is shown schematically. The tapped transformer 1 has a main winding 2 and a control winding 3 with different winding taps Ni, Nj, N _N which are switched on and off by the on-load tap changer 20 . For this purpose, the on-load tap changer 20 includes a selector 30, which can contact the different winding taps Ni, ..., Nj, ..., N _N of the control winding 3 by means of two movable selector contacts, and a diverter switch 40, which is the actual diverter switch the currently connected to the new, preselected winding tap performs. In the position of the _diverter switch 40 shown in FIG.

FIG. 2 shows an exemplary embodiment of a switching module in a perspective representation according to the improved concept. The switching module 10 includes a plate 50 made of a plastic, for example glass fiber reinforced plastic, or another electrically insulating material. The plate 50 is either designed as a milled part or made by injection molding. A selector unit 30 and a diverter switch unit 40 are arranged on the plate 50 . Powerless fixed contacts 31 are preselected via the selector unit 30, which in turn are electrically connected to the tapped windings of the tapped transformer (not shown). The load switch unit 40 is located on a separate cassette 60 which is inserted into a recess 51 of the plate 50 and is flush with the plate 50.

Furthermore, a drive unit 25 is arranged on the plate 50, essentially between the selector unit 30 and the diverter switch unit 40. The drive unit 25 is rotatably connected to a drive shaft (not shown). The drive shaft and thus also the drive unit 25 are driven by a motor drive (not shown).

FIG. 3 shows a detailed view of an exemplary embodiment of the switching module according to the improved concept. Here the cartridge 60 is in the extracted state. The cassette 60 can be inserted into the recess 51 of the plate 50 and pulled out by means of a handle 64 . For this purpose, the plate 50 has means for guiding 53 on the inner walls 52 of the recess 51, which are designed here as a groove. In this way, the service-relevant switching means of the diverter switch unit 40 can be easily removed from the plate 50 via the cassette 60, replaced or repaired and set again.

FIGS. 4 and 5 each show a detailed view of an exemplary embodiment of the cassette of the switching module in a perspective representation according to the improved concept.

The cassette 60, on which the switching means of the diverter switch unit 40 are attached, is shown in detail in both figures. FIG. 4 shows the first side 61 of the cassette 60, on which a vacuum interrupter 41 is arranged, and FIG. 5 shows the opposite second side 62 of the cassette 60, which carries a mechanical switching element 42 which is designed as a bridge switch that can be actuated linearly. The cartridge 60 further includes a plurality of leads 11 extending partially through the cassette 60 from the first side 61 to the second side 62, and an interface 13 for electrical connection to each second lead (not shown) associated with the panel 50. According to this embodiment, the electrical interfaces 13 are designed as screw connections. The screw connections are provided in close proximity to the cassette 60 to provide easy access to the electrical connections for service.

The cassette 60 also consists of a plastic, for example glass fiber reinforced plastic, or another electrically insulating material and is designed, for example, as a milled part or is produced by means of an injection molding process. A guide rail 65 is provided on the side walls 63 of the cassette 60, which works with the groove 53 on the inner walls 52 of the recess 51 of the plate 50 (cf. FIG. 3).

FIGS. 6 and 7 each show a detailed view of a further exemplary embodiment of the cassette of the switching module in a perspective representation according to the improved concept. This embodiment is similar to the variant in FIGS. 4 and 5, which is why only the differences are discussed below.

According to this embodiment, the electrical interfaces 13 are designed as a contact system. Instead of the connection for a screw connection, the lines 11 each have a plug contact 15 at one end. This can be inserted into a contact bridge 14, which is shown in more detail in FIG. A contact bridge 14 consists of two fixed contacts 17 which are spaced apart and arranged opposite one another. The fixed contacts 17 are held in position with a guide pin 18. The first plug contact 15, which is assigned to the first line 11 on the cassette 60, and a second plug contact 16, which is assigned to a second line 12 on the plate 50, are supplied inserted in the inserted state of the cassette 60 between the fixed contacts 17 of the contact bridge 14. About springs 19, which are arranged between a stop 80 of the guide pin 18 and a fixed contact 17, the fixed contacts 17 are pressed against the plug contacts 15 and 16, so that the fixed contacts 17 are electrically bridged and connected to each other.

FIG. 9 shows an exemplary embodiment of an on-load tap changer, which has a switching module according to the improved concept, in a perspective view.

In Figure 9, the on-load tap changer 20 is three-phase and has a total of three switching modules 10, each comprising a plate 50 and a cassette 60, each are designed according to the embodiments shown in Figures 2 to 8. The plates 50 are arranged in a longitudinal direction L of the on-load tap changer 20 along a drive shaft 22 one above the other and spaced apart from one another and are held in this position by means of a support structure 23 . The drive shaft 22 also extends along the longitudinal direction L of the on-load tap changer 20 and, by means of a motor drive 24, drives all three phases of the on-load tap changer 20 equally.

It is believed that the present disclosure and many of the attendant advantages thereof can be understood from the foregoing description. Furthermore, it is evident that various changes in the form, construction and arrangement of the components can be made without departing from the disclosed subject matter or without sacrificing all material advantages. The described embodiments are illustrative only and such changes are intended to be encompassed by the following claims. It is further understood that the invention is defined by the claims below.

REFERENCE MARKS

1 step transformer

2 trunk winding

3 control winding

10 switching module

11 first line

12 second line

13 electrical interface

14 contact bridge

15 first plug contact

16 second plug contact

17 fixed contact

18 guide pin

19 spring

20 on-load tap changer 21 load dissipation 22 drive shaft

23 shoring

24 motor drive

25 drive unit

30 voter unit

31 fixed contacts out of 30

40 diverter switch unit

41 vacuum interrupter

42 mechanical switching element 50 plate

51 recess 52 inner wall of 51

53 means of leadership

60 cassette

61 first page of 60 62 second page of 60

63 side panel of 60

64 grip

65 guide rail 80 stop

Ni , Nj, NN winding taps of 3

L Longitudinal direction of the on-load tap-changer

Claims

EXPECTATIONS

1. Switching module (10) for an on-load tap changer (20) for uninterrupted switching between winding taps (Ni, ... Nj, N _n ) of a tapped transformer (1), comprising: a selector unit (30) for power-free preselection of a selected winding tap (Nj); a diverter switch unit (40) for the actual diverter switch from the previous winding tap (Nj-i) to the preselected winding tap (Nj);

- a plate (50) on which the selector unit (30) and the diverter switch unit (40) are arranged; whereby

- the diverter switch unit (40) is arranged on a separate cassette (60) which is detachably connected to the plate (50).

2. switching module (10) according to the previous claim, wherein

- The diverter switch unit (40) comprises at least one vacuum interrupter (41) and/or at least one electronic power switching element and/or at least one mechanical switching element (42), in particular a bridge switch.

3. switching module (10) according to claim 1 or 2, wherein

- the cassette (60) has a first side (61) and a second side (62) opposite to the first side (61); the at least one vacuum interrupter (41) and/or the at least one electronic switching element is arranged on the first side (61) and the at least one mechanical switching element (42) is arranged on the second side (62).

4. switching module (10) according to any one of the preceding claims, wherein

- The plate (50) has a recess (51) with an open side, which comprises means for guiding (53) on at least two inner walls (52), via the at least two side walls (63) of the cassette (60) into the Recess (51) can be pushed in such that the cassette (60) is secured when pushed in and is flush with the plate (50).

5. switching module (10) according to any one of the preceding claims, wherein

- The switching module (10) has at least one electrical interface (13) via the first line (11) associated with the cassette (60) and a second line (12) associated with the plate (50) can be connected to one another.

6. Switching module according to claim 5, wherein - the electrical interface (13) is designed as a screw connection.

7. switching module according to claim 5, wherein

- the electrical interface (13) is designed as a contact system which has a contact bridge (14), a first plug contact (15) which is assigned to the cassette (60) and a second plug contact (16) which is assigned to the plate (50 ) is assigned to summarizes, wherein the first plug contact (16) is releasably connected to the contact bridge (14) is the verbun.

8. On-load tap changer (20) for uninterrupted switching between winding taps (Ni, ... Nj, ..., N _n ) of a step transformer (1), comprising at least one switching module (10) according to one of claims 1 to 7.