CN116134571A

CN116134571A - Selector for on-load tap-changer

Info

Publication number: CN116134571A
Application number: CN202180060922.XA
Authority: CN
Inventors: N·翁特赖纳
Original assignee: Reinhausen Machinery Manufacturing Co ltd
Current assignee: Reinhausen Machinery Manufacturing Co ltd
Priority date: 2020-08-27
Filing date: 2021-07-21
Publication date: 2023-05-16
Also published as: DE102020122451A1; WO2022042952A1

Abstract

The invention relates to a selector (10) for an on-load tap-changer (1), said selector comprising: -a carrier (11) having a first side (11.1) and an opposite second side (11.2); -at least one fixed contact (20) extending through the carrier (11) from a first side (11.1) to a second side (11.2), wherein-the fixed contact (20) has a first area (21) for guiding a load current and a second area (22) for cooling the fixed contact (20).

Description

Selector for on-load tap-changer

Technical Field

The present invention relates to a selector for an on-load tap-changer.

Background

On-load tap changers are known from the prior art and mostly have an on-load diverter switch and a selector. The on-load diverter switch with the vacuum interrupter and the switching resistor is arranged in a cylindrical container. The selector is constituted by a plurality of rods arranged in a circular shape. Contacts are arranged on the bars in different planes, which serve as terminals for the adjusting winding. Inside the selector, two selector arms are fastened to the switch post. These selector arms contact contacts on the lever. The selector contacts are always solid in construction and are arranged distally relative to each other.

Disclosure of Invention

The object of the present invention is to provide a selector for an on-load tap changer which, despite its compactness, can withstand high temperatures and which ensures safe operation.

This object is achieved with a selector according to claim 1. The features of the dependent claims form advantageous refinements of the invention.

The invention proposes a selector for an on-load tap-changer, said selector comprising:

a carrier having a first side and an opposite second side,

at least one fixed contact extending from a first side through the carrier to a second side,

wherein:

the stationary contact has a first region for conducting a load current and a second region for cooling the stationary contact.

By specifically adding a second part or region for cooling the fixed contact to the fixed contact, a passive cooling system is realized in the selector and thus in the on-load tap changer in a particularly simple manner. The fixed contacts in the selector are typically only as long as preset by electrical requirements. Supplementing the fixed contact with a second area/section having the additional function of cooling the fixed contact is firstly contradictory to the usual requirements. The second part or region of the fixed contact is here sufficiently large to be able to release sufficient thermal energy into the cooling medium. On the other hand, the fixed contact is just small or short enough that a high load current can be conducted and nevertheless no flashover occurs between the fixed contact and other voltage-conducting components.

The carrier can be constructed in any desired manner and method and can be produced, for example, as a plate or plate-shaped injection molded part. The carrier may be made of plastic, glass fiber reinforced plastic or another arbitrary electrically insulating material.

The fixed contact can be constructed in any manner and method and is, for example, designed in one piece or in multiple pieces, i.e. made up of one or more sub-blocks. Furthermore, the fixed contact may be rounded at its free end or have a shielding. The fixed contact may be integrally designed as an L-shaped or T-shaped wire.

The second region of the fixed contact may have the same cross-section as the first region or a different cross-section.

It may be provided that the first and second support members,

providing a first contact-making contact which in a stationary state contacts the stationary contact,

-a load current flows through the first contact-making contact and the first area of the stationary contact.

The contact between the contact-making contact and the fixed contact can be made by means of a contact point or a contact surface.

It may be provided that the second region or the portion of the fixed contact is 1 to 25mm long. The second region is here essentially used for cooling and is not used for conducting the load current. The second section or region is furthermore at least as long as the first section or region of the fixed contact.

The first region or portion of the fixed contact generally terminates where the first make contact contacts the fixed contact. In other words, the first region or first portion of the fixed contact ends where the main load current of the on-load tap-changer is no longer directed. The opposite applies to the second portion or region of the fixed contact. Substantially no load current flows through the second portion or region.

It may be provided that the first and second support members,

the fixed contact is held in the carrier by at least two tabs.

-the carrier has at least one indentation at the fixed contact.

The fixed contact is additionally held or fixed in the carrier by a tab. The contact surface between the carrier and the fixed contact is thus increased and the retention is thus improved. The gap enables the insulating oil to flow along the fixed contact. Thereby, the contact is additionally cooled. The number of tabs and notches may vary between at least one and more than ten. The shape of the notch may be variable, such as circular, polygonal, or sickle-shaped. The tab may extend outwardly from the carrier along the fixed contact in the direction of the selector arm.

It may be provided that the first and second support members,

a first selector arm is provided, on which the first closing contact is arranged,

a second selector arm is provided, on which a third contact is arranged,

a plurality of fixed contacts are provided, which are arranged circularly around the selector arm,

-the first selector arm, the first contact-making contact, the second selector arm, the third contact-making contact and the fixed contact form a fine selector.

It may be provided that the first and second support members,

a second contact is provided, which is arranged on the first selector arm,

-providing a fourth contact arranged on said second selector arm.

It may be provided that the first and second support members,

the first contact is arranged directly below the second contact,

-said third contact is arranged directly below said fourth contact.

It may be provided that the first contact is arranged slightly offset with respect to the second contact and the third contact is arranged slightly offset with respect to the fourth contact. The contact-making contacts are fastened to the corresponding selector arms.

It may be provided that the first and second support members,

a pre-selector arm, a pre-selector rocker arranged with a fifth contact point are arranged on the carrier,

-one of the pre-selector arm, the pre-selector rocker, the fifth closing contact and the fixed contact forms a pre-selector or a commutator.

It may be provided that the first and second support members,

the selector is designed as part of an on-load tap-changer module.

Here, a load changeover switch is also arranged on the carrier in addition to the selector. The on-load switching switch may have a vacuum switching tube, a bridge switch and a resistor or a reactance.

Drawings

The invention and its advantages will be described in more detail below with reference to the drawings. Here, it is shown that:

FIG. 1 shows a selector;

FIG. 2 shows a detailed cross-sectional view of the selector;

fig. 3 shows a further detailed view of the selector;

FIG. 4 shows a selector with a pre-selector;

fig. 5 shows an on-load tap changer with three selectors.

Detailed Description

The same reference numerals are used for identical or identically functioning elements of the invention. Furthermore, for the sake of clarity, only the reference numerals necessary for describing the respective drawings are shown in the respective drawings. The illustrated embodiment is merely an example of how a selector according to the invention may be constructed; and thus is not a final limitation of the present invention.

Fig. 1 shows a selector 10 according to the invention for an on-load tap-changer 1. The selector 10 has a carrier 11 which is made of plastic, GFK or other electrically insulating material. The carrier 11 is produced from one piece by milling or by means of an injection molding method. A first selector arm 12 of the selector 10 is arranged on the first side 11.1 of the carrier 11. The first selector arm 12 is designed as a maltese gear. The first selector arm 12 is rotatably supported and performs a rotational movement about a selector shaft 19. Furthermore, the first selector arm 12 carries at least a first 13 and a second 14 contact. A plurality of stationary contacts 20 are arranged circularly around the first selector arm 12. The fixed contact 20 is designed such that it extends from a first side 11.1 of the carrier 11 to an opposite second side 11.2 of the carrier 11. On the second side 11.2 of the carrier 11 a second selector arm 15 with a third contact 16 and a fourth contact 17 is arranged. The

selector arms

12, 15, the fixed contacts 20 arranged in a circle, and the contact-making

contacts

13, 14, 16, 17 form a fine selector 18.

Fig. 2 shows a detailed cross-sectional view of the selector 10. In particular, a section 23 is provided through the carrier 11, one of the fixed contacts 20 and the first contact 13 and the second contact 14. The first contact point 13 and the second contact point, in the closed state, contact the fixed contact point 20 at the ring Zhou Cejie and establish a contact point for conducting the load current.

It can be seen here that the fixed contact 20 is composed of two parts or is divided into two regions. The first region or section 21 is used here for conducting the current and in particular for conducting the load current. The current flows from the winding tap via the corresponding fixed contact 20 through the first contact 13 to the load changeover switch and finally to the load lead. The fixed contact 20 may also be an integral part of the pre-selector or the commutator.

The second portion/region 22 of the fixed contact has substantially no current flowing through it. More specifically, no load current flows through the second portion/region 22 of the contact. The second portion/region 22 serves to cool the entire fixed contact 20. The heat generated in the fixed contact 20 is transferred via this second freely established part/region 22 (which is preferably 1 to 25mm long) and in particular its surface to the insulating medium in which the selector is located.

The difference between the first and second portions/regions 21, 22 of the fixed contact 20 can be roughly determined at the contact point or contact surface, which is produced between the fixed contact 20 and the first contact-making contact 13. Substantially above the contact point, the second portion/region 22 of the fixed contact 20 is the portion/region through which no load current flows.

The free end of the second portion 22 is preferably provided with a radius. This radius prevents voltage flashovers between the fixed contact and other potential-conducting elements. The generation of voltage points/voltage peaks is prevented. Thus, there is a uniform electric field across the switch.

The first contact 13 is fastened to the selector arm 12 with a slight offset relative to the second contact 14. In this way, it is achieved that, during switching on, first the first switching contact 13 is brought into contact with the fixed contact 20 and then, next to the second switching contact 14, is brought into contact with the fixed contact 20. In this case, the offset is designed to be minimal, in particular a few millimeters.

Fig. 3 shows a further detail view of the selector 10 with a plurality of fixed contacts 20. Here, each fixed contact 20 extends from the first side 11.1 to the second side 11.2. In this case, each fixed contact 20 is held in the carrier 11 by three webs 30. Embodiments with two, four, five or more tabs 30 are also possible. The carrier 11 has three notches 31 between the respective tabs 30. These indentations are formed directly at the fixed contacts 20 in the carrier 11. This makes it possible for the insulating medium in which the selector 10 is located to flow past the fixed contact 20, and for the fixed contact 20 to be cooled in a targeted manner. With a horizontal arrangement of the selector 10, a flow of the insulating medium and thus a convective cooling in the region of the fixed contact 20 can be achieved. The number of indentations 31 may be arbitrarily adapted, for example to one, two, four, five or more indentations 31.

Fig. 4 shows a further view of the selector 10. On the second side 11.2 of the carrier 11, a pre-selector arm 41 is arranged, which is likewise designed as a maltese gear. The preselector arm 41 is rotatably supported and likewise performs a rotational movement about a preselector axis 44. Additionally, the pre-selector rocker 42 is provided with a fifth contact 43, which can be switched by a pivoting movement between the two fixed contacts 20. The fixed contact 20, the pre-selector rocker 42, together with the contact 20 and the pre-selector arm 41 form a pre-selector 40 or a commutator, which may be an integral part of the selector 10.

The fixed contact 20 of the preselector 40 or commutator corresponds to the contact of the fine selector 18. Thus, the selector 10 has the same configuration of the fixed contacts 20.

The fixed contact 20 is designed as a curved or L-shaped element. These elements may be composed of one or more sub-blocks.

Fig. 5 shows an on-load tap changer 1 with three on-load tap changer modules 2. Each on-load tap-changer module 2 has a selector 10 which is arranged on a carrier 11, respectively. Furthermore, on each carrier 11 a load changeover switch is arranged. The on-load transfer switch has a vacuum switch tube, a bridge switch, and a resistor or reactance. The driving is performed by a motor which operates the drive shaft 33.

List of reference numerals

1 on-load tap-changer

2 on-load tap-changer module

10. Selector

11. Carrier body

11.1 11 on the first side

11.2 11 second side of

12. First selector arm

13. First contact

14. Second contact

15. Second selector arm

16. Third contact

17. Fourth contact

18. Fine selector

19. Selector shaft

20. Fixed contact

21 a first portion/region of said 20

22 a second portion/region of said 20

23. Cross section of

30. Tab

31. Notch

40 pre-selector/commutator

41. Preselector arm

42. Rocker of preselector

43. Fifth contact

44. Preselector shaft

Claims

1. A selector (10) for an on-load tap-changer (1), the selector comprising:

a carrier (11) having a first side (11.1) and an opposite second side (11.2),

at least one fixed contact (20) extending through the carrier (11) from a first side (11.1) to a second side (11.2),

wherein,,

-the fixed contact (20) has a first region (21) for guiding a load current and a second region (22) for cooling the fixed contact (20).

2. Selector (10) according to claim 1, wherein,

-providing a first contact-making contact (13) which in a stationary state contacts the stationary contact (20),

-the load current flows substantially through the first contact-making contact (13) and the first area (21) of the fixed contact (20).

3. Selector (10) according to any one of claims 1 to 2, wherein,

-the second area (22) of the fixed contact (20) is up to 1mm to 25mm long.

4. A selector (10) according to any one of claims 1 to 3, wherein,

-the carrier (11) has at least one notch (31) at the fixed contact (20).

5. Selector (10) according to any one of claims 1 to 4, wherein,

-the fixed contact (20) is held in the carrier (11) by at least two tabs (30).

6. Selector (10) according to any one of claims 1 to 5, wherein,

a first selector arm (12) is provided, on which a first contact-making contact (13) is arranged,

a second selector arm (15) is provided, on which a third contact-making contact (16) is arranged,

-each of said selector arms (12, 15) is rotatably supported directly on top of each other on a selector shaft (19) in a manner separated by a carrier (11).

7. Selector (10) according to any one of claims 1 to 6, wherein,

a plurality of fixed contacts (20) are provided,

the plurality of fixed contacts (20) are circularly arranged around each selector arm (12, 15),

-the first selector arm (12), the first closing contact (13), the second selector arm (15), the third closing contact (16) and the plurality of fixed contacts (20) form a fine selector (18).

8. Selector (10) according to any one of claims 1 to 7, wherein,

a second contact-making contact (14) is provided, which is arranged on the first selector arm (12),

-a fourth contact-making contact (17) is provided, said fourth contact-making contact being arranged on the second selector arm (15).

9. Selector (10) according to any one of claims 1 to 8, wherein,

the first contact-making contact (13) is arranged on the first selector arm (12) directly above the second contact-making contact (14),

-said third contact (16) is arranged on the second selector arm (15) directly below the fourth contact (17).

10. Selector (10) according to any one of claims 1 to 9, wherein,

provided with a pre-selector arm (41) arranged on the carrier (11),

a pre-selector rocker (42) is provided, on which a fifth contact-making contact (43) is arranged,

-a pre-selector arm (41), a pre-selector rocker (42), a fifth closing contact (43) and two of said fixed contacts (20) form a pre-selector or a commutator.