WO2014001029A1

WO2014001029A1 - Three-position load isolating switch for medium-voltage switchgear assemblies

Info

Publication number: WO2014001029A1
Application number: PCT/EP2013/061437
Authority: WO
Inventors: Stefan Hohmann; Daniel Pesch; Stefan Wolf; Rene Zlydnik
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-06-25
Filing date: 2013-06-04
Publication date: 2014-01-03
Also published as: CN104335312B; CN104335312A; ES2601385T3; EP2845213A1; EP2845213B1

Abstract

In order to design a three-position load isolating switch for medium-voltage switchgear assemblies, which three-position load isolating switch can be produced in a cost-effective manner with a compact construction, a three-position load isolating switch (1), for medium-voltage switchgear assemblies having a main contact system, is formed from a first fixed contact (2) and from a second fixed contact (3), said fixed contacts being situated diametrically opposite one another, and from a moving contact (4) which can be rotated by means of a rotary support (7) which is arranged centrally between the first fixed contact (2) and the second fixed contact (3), so as to form a main current path in a first position of the rotatable moving contact (4), so as to form an isolating section in a second position of the rotatable moving contact (4) and so as to form an earthing position with an earthing contact system in a third position of the rotatable moving contact, and also from a secondary current path which is formed from the first fixed contact (2), from the second fixed contact (3), from an arc-quenching contact system (9) and also from a first sliding contact (15) and a second sliding contact (16) for forming a conductive connection to the rotatable moving contact (4) in a rotation angle region of the rotatable moving contact (4), which rotation angle region is located between the first position and the second position, in such a way that, when a rotary movement is initiated in the rotatable moving contact (4), commutation of an alternating current which flows across the switchgear from the main current path to the secondary current path is possible, wherein the rotatable moving contact (4) has means (18, 19, 25) for interrupting the arc-quenching contact system (9), and, when the arc is quenched and a further rotary movement is initiated, the isolating section can be formed.

Description

description

Three-position switch-disconnector for medium-voltage switchgear

The invention relates to a three-position circuit breaker for medium-voltage switchgear with a main contact system, formed from a first fixed contact and a second fixed contact, which are diametrically opposed, and a rotatable by means of a centrally between the first fixed contact and the second fixed contact rotary support movable contact forming a main current path in a first position of the moving contact, forming a separation distance in a second position of the rotatable moving contact and forming a grounding position with a grounding contact system in a third position of the rotatable moving contact, and a Nebenstrompfad formed from the first fixed contact, the second fixed contact, a Löschkontakt- system and a first sliding contact and a second sliding contact for forming a conductive connection with the rotatable moving contact in a position between the first position and the second position chen turning angle range of the rotatable moving contact such that upon initiation of a rotary motion in the rotatable moving contact commutation tion of an alternating current flowing through the switching device from the main current path is made possible on the secondary current path, wherein the rotatable moving contact comprises means for interrupting the extinguishing contact system, and with extinguished arc and Initiating further rotational movement, forming the separating gap is made possible, wherein the extinguishing contact system comprises a vacuum interrupter.

A load-break switch for medium-voltage switchgear is known, for example, from DE 10 2004 006 476 A1 and comprises a main contact system and a shunt branch, in which shunt branch an extinguishing contact arrangement for extinguishing an arc and a disconnect contact arrangement for providing a dielectric strength are provided. A three-position circuit breaker of the type mentioned is known from EP 0693763 Bl. Object of the present invention is to form a three-position circuit breaker of the type mentioned, which is inexpensive to produce in a compact design. This is achieved according to the invention in that the means comprise a cam for actuating a rocker coupled to a moving contact connecting bolt of the vacuum interrupter by means of a guide element and the means further comprise a folding mechanism such that when the three-position load disconnecting switch is switched on, the third or second position of the rotatable movement contact in its first position the extinguishing contact system is interrupted. Such a three-position circuit breaker on the one hand has a compact design, because by the diametrical arrangement of the first fixed contact and second fixed contact to each other and the interposed rotatable moving contact an arrangement of main flow path and Nebenstrompfad in a small space next to each other is made possible by the rotational movement of a commutation over the Switching device guided alternating current from the main current path to the secondary current path is made possible. On the other hand, such a switching device has a cost-effective design, because by the arranged in the secondary current path extinguishing contact system both this and the first and second sliding contacts and other connecting means to the first and the second fixed contact of inexpensive material, such as steel or stainless steel or aluminum or the like , can be produced because a current is only briefly conducted during a switching operation via the secondary current path until, after arc quenching in the quenching contact system, a transfer to the disconnected position of the three-position circuit breaker is achieved. occurs, so that the requirements of the material properties of the secondary flow path are lower than the requirements for the material properties of the main flow path. The structure with a cam is mechanically simple and therefore compact and cost-effective, since only work against the low spring force of the contact pressure spring of the extinguishing contact system is to be done with this structure and by the folding mechanism is ensured in an advantageous manner that a switch-on of the switching device by initiating the rotational movement in the opposite direction and transfer of the rotatable moving contact from the third or the second position to the first position of the switching is carried out without electrical interference over the Nebenstrompfad and in particular without involvement of the vacuum interrupter of the extinguishing contact system, so that the vacuum interrupter no requirements regarding Einschaltfestigkeit or the like are made, because a Einschaltlichtbogen is ignited during the switching between the rotatable moving contact and the first and second fixed contacts, which is particularly in Anordnun g of the three-position circuit breaker in a filled with an insulating medium, such as an insulating gas or insulating liquid housing a simple, in contrast to the switching in the vacuum interrupter cost-effective way to perform a switch-on ges represents.

In an advantageous embodiment of the invention, the vacuum interrupter by means of a contact pressure spring

closable contact system. The contact system of the vacuum interrupter is held by the contact pressure spring in its closed state, as long as the means of the rotatable moving contact to interrupt the extinguishing contact system does not attack this, so that only a small spring force is necessary by the arrangement of the extinguishing contact system in the secondary flow path especially for the contact pressure spring because no short-circuit current is routed via the secondary current path, it is switched on or off. In an advantageous embodiment of the invention, the grounding contact system is formed by a ground contact, the second sliding contact as a ground counter contact and the rotatable movement contact. As a result, a three-position switch-disconnector with the ON, OFF and EARTH positions is formed in a simple and compact manner.

The invention will be explained in more detail below with reference to the drawing and an embodiment with reference to the accompanying figures. Show it:

Figure 1: an embodiment of a switching device according to the invention in a first position;

Figures 2 and 3: the switching device of Figure 1 in one

Disconnected position or a grounding position;

4 shows a view of an embodiment of a three-phase switching device according to the switching device of Figure 1.

1 shows a three-position circuit breaker 1 for use in medium-voltage switchgear, which are not shown in detail figurative, the three-position circuit breaker 1 with a first fixed contact 2 with a busbar connection of the switchgear is connectable and with a second fixed contact 3 with a cable outlet of the middle - voltage switchgear is connectable. The first fixed contact 2 and the second fixed contact 3, which are preferably formed of copper as a material, together with a rotatable moving contact 4 form a main contact system and a main current path of the three-position circuit breaker 1. The moving contact 4 is designed as a pair of knives and comprises a first pair of knife ends 5 and a second pair of knife ends 6 and a figured not further shown conductive connection between the first pair of knife ends 5 and second pair of knife ends 6 and is located in the figure 1 in a first Position in which the first pair of knife ends 5 forms a conductive connection with the first fixed contact 2 and the second pair of knife ends 6 with the second fixed contact 3 forms a conductive connection, so that a current flow through the three-position circuit breaker 1 and over the main current path is possible. The rotatable moving contact 4 is fastened to a rotary support 7, in which rotary support 7 a drive movement of a drive likewise not shown in the figure for rotation of the rotary support 7, and thus rotation of the rotatable moving contact 4, is made possible. On the first fixed contact 2, an extinguishing contact system 9 is electrically connected by means of a conductive connection 8, which extinguishing contact system 9 is formed by a vacuum interrupter 10 with moving contact 11 and fixed contact 12, wherein the extinguishing contact system 9 in the figure 1 is in the closed state by a contact pressure spring The moving contact 11 of the extinguishing contact system 9 is in turn conductively connected to a first sliding contact 15. A second sliding contact 16 is connected to the second by means of a further conductive connecting element 17 Fixed contact 3 electrically conductively connected, so that after initiating a rotational movement in the rotary support 7 and rotation of the rotatable moving contact 4 in a contact position in which the first knife pair end 5 and the second knife pair end 6 of the rotatable moving contact 4 m it is the first sliding contact 15 and the second sliding contact 16 in a conductive connection, a Nebenstrompfad on the first fixed contact 2, the conductive connection 8, the closed LöschkontaktSystem 9, the first sliding contact 15, the rotatable moving contact 4, the second sliding contact 16, the conductive connecting element 17 and the second fixed contact 3 is formed, as explained in more detail below with reference to Figure 2. The first sliding contact 15 and the second sliding contact 16 may be formed of steel, for example. On the rotatable moving contact 4 is still provided a cam 18, which has a cam track 19 through which in a Rotary movement of the rotatable moving contact 4, a rocker 20 is actuated, which rocker 20 is rotatably mounted at a pivot point 21 and guided by a guide pin 22 in its movement along the curved path, wherein a guide element 23 is provided, through which the rocker 20 the moving contact Connection pin 14 of the extinguishing contact system 9 moves and the extinguishing contact system 9 opens. The cam track 19 in this case has a first portion 19 ', whose course is provided for opening the extinguishing contact system 9, and a second portion 19''with a maximum radius, is ensured by the holding open the extinguishing contact system via the guide pin 22.

A grounding contact 24 of a grounding contact system is provided for forming a grounding position of the three-position load-break switch 1, which will be explained in more detail with reference to FIG. Arranged on the cam plate 18 is a folding mechanism 25 which has a rotary lever 26 and a spring lever 27 and also a spring 28, and which is provided so that when the three-position load-break switch 1 is switched on the extinguishing contact system 9 remains in its opened state, while the rotatable moving contact 4 is transferred from the grounding position or the switch-off position back into the first position by introducing an opposite rotational movement, in that the curved track 19 retains its maximum radius by the folding mechanism, as explained in more detail below in FIG. When switching off the spring lever 27, which is rotatably supported on the rotary lever 26, forced by the guide pin 22 from its position of Figure 1 away, but as soon as by the rotational movement of the guide pin 22 on the curved path has reached the maximum radius of the same Spring 28 transferred back to its original position, so that at a switch-on and a rotational movement back into the area of the curved path 19 has the maximum radius and the extinguishing contact system 9 is held by the guided on the maximum radius guide pin 22 in the open state. The three-position switch-disconnector 1 is included arranged in a housing 29 which can be filled with an insulating gas or an insulating liquid and by means of fastening elements, of which only one example is denoted by 30, can be fastened and mounted on the medium-voltage switchgear.

The function of the three-position load-break switch 1 of FIG. 1 is explained in more detail below with reference to FIGS. 1 to 3. As already stated above, the three-position circuit breaker 1 is in its first position with trained Hauptstrompfad over the first fixed contact 2, the rotatable moving contact 4 and the second fixed contact 3. In the introduction of a drive movement in the rotary support 7 for carrying out a Switching process and

Finally, to form a separating path for dielectric separation, a position, which is not shown in FIG. 1, is reached, in which the first knife pair end 5 is in a conductive connection both with the first fixed contact 2 and with the first sliding contact 15 and the second pair of knife ends 6 with the second

Fixed contact 3 and the second sliding contact 16 is in electrically conductive connection, so that at this time a commutation of the main current path is introduced to the secondary flow path with the extinguishing contact system 9 closed. Upon further rotational movement, the first knife pair end 5 and the second knife pair end 6 are then only in conductive connection with the first sliding contact 15 and the second sliding contact 16, so that the main current path is interrupted and the commutation is completed. In this case, the cam plate 18 engages with its cam track 19 on the rocker 20, so that, by rotation of the rocker 20 about the pivot point 21 via the guide element 23 of the moving contact terminal pin 14 of the extinguishing contact system 9 is caused to move, which against the spring force the contact pressure spring 13 can be introduced and leads to the opening of the extinguishing contact system 9, so that an arc in the extinguishing contact system 9 of the vacuum interrupter 10 is ignited in the secondary flow path, which at a current zero crossing of the guided via the switching device Wechselstro- mes is deleted. Upon further rotational movement, the position of Figure 2 is reached, in which the rotatable moving contact 4 is in a second position with trained disconnected position and completely interrupted current flow, wherein further the cam plate 18 with its curved path 19 still attacks on the rocker 20 and the extinguishing contact system 9 of the secondary flow path remains open, and there is a sufficient distance between the pair of knife ends 5 or 6 and the fixed contacts 2 or 3 or sliding contacts 15 or 16 to provide a dielectric separation condition of the

To meet switching device or medium-voltage switchgear.

In other words, between the first position of the switched-on state of the three-position circuit breaker

1 of Figure 1 and the second position with trained separation distance of the three-position circuit breaker 1 of the figure

2 by introducing a rotary motion in the rotary support 7 and thus the rotatable moving contact 4 a rotation angle range of the rotatable moving contact 4 so passed through that initially a commutation of the alternating current flowing through the switching device from the main current path is made possible on the Nebenstrompfad and extinguished arc and further rotational movement training the separation distance is reached while reaching the second position of Figure 2.

When initiating further rotational movement, the rotatable moving contact 4 finally reaches its third position as in FIG

3, in which it is in conductive connection with the second fixed contact 3 on the one hand via the first knife pair end 5 and with the ground contact 24 via the second pair of knife ends 6, so that a grounding of all the second fixed contact 3 in a conductive connection system parts is formed ,

A switch-on of the three-position circuit breaker 1 is done by initiating a rotational movement in the opposite direction to the rotational movement of the switching of the in the disconnected position or the grounding position three-position circuit breaker 1, as shown in Figure 3, and rotation of the rotatable moving contact 4 back to the position of Figure 1, to the first knife pair end 5 with the first fixed contact 2 and the second knife pair end 6 with the second fixed contact 3 comes into conductive connection.

By means of the folding mechanism 25, it is ensured that the extinguishing contact system 9 remains in its opened state during the switch-on process because the spring 28 gives the maximum radius of the cam track for guiding the guide pin 22, as already described above. This makes it possible to cost-effectively carry out the vacuum interrupter 10 of the extinguishing contact system 9, since this is not involved in the switch-on and thus no special requirements for the switch-on of the vacuum interrupter 10 must be made. Furthermore, in the arrangement of the secondary flow path can be formed by low-cost materials, such as steel, stainless steel or aluminum, because on the secondary flow path only briefly briefly a current is conducted and in particular no short-circuit current occurs in the secondary flow path.

FIG. 4 shows a three-phase switching device 1, each phase 31, 32 or 33 being designed according to the exemplary embodiment of FIGS. 1 to 6, of which the housings 29 can be seen, and the individual phases 31, 32 and 33 being connected to one another via connecting elements 34 are connected, so that a simultaneous actuation of all phases by initiating a rotational movement of a drive not shown in the figure is possible in the rotary support 7. The grounding contacts 24 of the phases 31, 32 and 33 are connected to each other via a ground bus 35, which in turn is earthed. A frame 36 is as a holder of the three-position load break switch 1 and for arranging busbar terminals 37, 38 and 39th and provided by cable outlet terminals 40, 41 and 42 of the switchgear.

LIST OF REFERENCE NUMBERS

1 three-position switch-disconnector

2 first fixed contact

3 second fixed contact

4 moving contact

5 first pair of knife ends

6 second pair of knife ends

7 rotary supports

8 conductive connection

9 extinguishing contact system

10 vacuum interrupter

11 moving contact

12 fixed contact

13 contact pressure spring

14 moving contact connecting bolts

15 first sliding contact

16 second sliding contact

17 connection element

18 cam

19 curved track

19 'first section

19 '' second section

20 seesaw

21 pivot point

22 guide pins

23 guide element

24 earthing contact

25 folding mechanism

26 rotary lever

27 spring lever

28 spring

29 housing

30 fastener

31, 32, 33 phases

34 connecting elements

35 earthing bar

36 frames 37, 38, 39 Busbar connections 40, 41, 42 Cable outlet connections

Claims

claims

1. Three-position switch-disconnector (1), for medium-voltage switchgear with a main contact system, formed of a first fixed contact (2) and a second fixed contact (3), which are diametrically opposed, and one by means of a centrally between the first fixed contact (2) and the second fixed contact (3) arranged rotary support (7) rotatable moving contact (4) to form a main current path in a first position of the rotatable moving contact (4), forming a separation distance in a second position of the rotatable moving contact (4) and forming a grounding position with a grounding contact system in a third position of the rotatable movement contact, and a secondary current path, formed from the first fixed contact (2), the second fixed contact (3), an erase contact system (9) and a first sliding contact (15) and a second sliding contact (16) for forming a conductive connection with the rotatable moving contact (4) in an intermediate the rotational angle range of the rotatable moving contact (4) located in the first position and the second position such that commutation of an alternating current flowing via the switching device from the main current path to the secondary current path is possible when a rotary motion is introduced into the rotatable moving contact (4), wherein the rotatable moving contact ( 4) comprises means (18, 19, 25) for interrupting the extinguishing contact system (9), and when the arc is extinguished and initiating further rotational movement forming the separation distance is possible, wherein the extinguishing contact system (9) comprises a vacuum interrupter (10), characterized in that the means (18, 19, 25) comprise a cam plate (18) for actuating a rocker (20) coupled to a moving contact connecting bolt (14) of the vacuum interrupter (10) by means of a guide element (23), and the means (18, 19 , 25) further comprise a folding mechanism (25) such that at a switch-on of the Dreistellungsla switch (1) from the third or the second position of the rotary switch Baren moving contact (4) in its first position the erase contact system (9) is interrupted.

2. Switching device according to claim 1,

The vacuum interrupter (10) has a contact system which can be closed by means of a contact pressure spring (13).

3. Switching device according to claim 1 or 2 ,,

That is, the grounding contact system is formed by a grounding contact (24), the second fixed contact (3) is formed as a grounding mating contact, and the rotatable mover (4) is d.