EP0959483B1 - Load break switch with arc extinguishing chamber - Google Patents

Abstract

The MV load breaker switch has an arc extinction chamber, a movable switch blade (11), a pressure chamber and an expansion chamber with an opening which can be at least partially closed, the closable opening area providing an auxiliary opening (9) in the form of a slit, for passage of the switch blade shaft.

Description

The invention relates to a switch with extinguishing chamber, in particular Medium-voltage switch-disconnector for voltages between 6 and 36 kV.

To arcs when opening the contacts of a switch-disconnector It is well known extinguishing chambers to extinguish as quickly as possible to be arranged in a secondary flow path in which only briefly, immediately after opening the main contact, power over one temporarily in on position lagging contact flows. One arranged in the quenching chamber movable contact or switching pin or -messer interrupts the bypass circuit. The resulting Arc is extinguished in the quenching chamber.

The knife- or pin-shaped contact or switching pin is between Arranged bodies that release gas when heated (hard gas principle). The pen or knife moves when switching on and off between these bodies. Under the influence of heat, the emanating from the arc resulting when switching off, builds on the one hand by heating the air present in the quenching chamber, on the other hand by the evolution of gas pressure, the one Gas flow creates the cool and the arc as fast as possible should delete.

The requirements for medium-voltage switchgear are constantly increasing. While so far, switching devices that called "life" 20 load shedding cope with the market, 100 load shutdowns will now be added Voltages of 12 and 24 kV and a current of 630 A required. Around It is always possible to switch off more and more power required to build larger and more pressure-resistant extinguishing chambers that way are dimensioned that for the cancellation of the Abschaltlichtbogens required extinguishing gas in the required amount provided and will withstand the pressure generated by the shutdown. However, the room in medium-voltage switchgear is very much is limited and the plant dimensions are largely determined by the Switch size can be determined, the dimensions of the Switchgear despite the increased demands on the breaking capacity not be increased significantly.

Therefore, it is currently common for reasons of space for each of the voltage series (10, 20, 30 kV) to build different extinguishing chambers, To build the switches of the respective voltage series as small as possible can.

They are extinguishing chambers, for example from the German Offenlegungsschrift 195 40 552 or from German patent application 195 22 852 known, which also in terms of the lowest possible Space requirements were developed.

Thus, German Patent Application Laid-Open 195 40 552 discloses one in one Support insulator integrated extinguishing chamber, each located between the Post insulators of a pole is located. The one in the quenching chamber Switching pin turns off along a straight trajectory pulled out of the quenching chamber. This straight-line movement claims relatively much space, since at least the length to which the switching pin from the Chamber is pulled outside the extinguishing chamber in extension this must be kept free for the switching movements.

To reduce this space requirements beat the documents DE 195 22 852 and FR 2034118 a tubular quenching chamber with a Schaltstift ago, both of which have the shape of a circle segment. Of the Switch pin is so deflected over connections at a pivot point that He performs a movement that is due to his form and that of his Extinguishing chamber predetermined circular path is located. To the switching pin off his contact position to pull out of the quenching chamber, although already claimed considerably less space than in the previously described Extinguishing chamber.

However, the extinguishing chambers described do not meet today's Demands on medium-voltage switchgear after 100 load shutdowns under the above mentioned conditions of performance.

Against this background, the invention is based on the problem, a the required shutdown performance resistant, flameproof To build fire chamber, which takes up the least possible space and as universally applicable.

To solve this problem, a quenching chamber with the in Main claim specified characteristics proposed. advantageous Embodiments are to be taken from the subclaims.

The device according to the invention makes it possible to use switch blades into the quenching chamber, so that the quenching chamber to the to meet increased performance requirements, greater could be designed without the space required for switch blades plus extinguishing chamber has risen overall, so that despite performance increase the existing grid dimensions of the switching cells are met can. Existing medium-voltage switching devices can thus be easily retrofitted with the devices of the invention.

Moreover, the quenching chamber according to the invention is designed to that they are for different voltages, for example 12 and 24 kV, can be used. Due to the fact that a quenching chamber for multiple voltage series can be used, arises considerable cost advantage.

Within the quenching chamber body in a conventional manner provided when heating gas-emitting material. these can Have plate shape and in the on state against the Press the switch pin or the blade contact tip. Any further form of this Body is conceivable.

Fig. 1a

einen Querschnitt durch eine Löschkammer, in ausgeschaltetem Zustand;

Fig. 1b

einen Schnitt durch eine Löschkammer gemäß Fig. 1a entlang der Linie A - A;

Fig. 2a

einen Querschnitt durch eine Löschkammer gemäß Fig. 1a, bei der sich das Schaltmesser in einer Mittelstellung zwischen ein- und ausgeschaltetem Zustand befindet;

Fig. 2b

einen Schnitt durch eine Löschkammer gemäß Fig. 2a entlang der Linie A - A;

Fig. 3a

einen Querschnitt durch eine Löschkammer gemäß Fig. 1a, in eingeschaltetem Zustand;

Fig. 3b

eine Ansicht einer Schaltkammer gemäß Fig. 3a aus der Richtung A;

Fig. 4a

einen Querschnitt durch ein weiteres Ausführungsbeispiel einer Löschkammer, in eingeschaltetem Zustand; und

Fig. 4b

eine Ansicht einer Löschkammer gemäß Fig. 4a aus der Richtung A.

In the following the invention will be explained in more detail with reference to the embodiments illustrated in the drawing. Show it:

Fig. 1a

a cross section through a quenching chamber, in the off state;

Fig. 1b

a section through a quenching chamber of Figure 1a along the line A - A.

Fig. 2a

a cross-section through a quenching chamber of Figure 1a, in which the switch blade is in a middle position between on and off state.

Fig. 2b

a section through a quenching chamber of Figure 2a along the line A - A;

Fig. 3a

a cross section through a quenching chamber of Figure 1a, when switched on.

Fig. 3b

a view of a switching chamber of Figure 3a from the direction A;

Fig. 4a

a cross section through another embodiment of a quenching chamber, when switched on; and

Fig. 4b

a view of a quenching chamber of FIG. 4a from the direction A.

In Fig. 1a, a quenching chamber 1 is shown, which consists of a housing. 2 consisting in a pressure chamber 3 and an expansion chamber. 4 divided by a wall 5 with an opening 6 from each other are separated. In the pressure chamber 3 is located on the Expansion chamber 4 side facing away from a fixed contact. 7

The expansion chamber 4 has on its wall 5 opposite Side an opening 8 on, which is also in the lower range of Expansion chamber 4 extends and there virtually an additional opening. 9 forms.

The openings 8 and 6 serve the passage of the contact tip of a movable switch blade 11 of the secondary flow path through the pressure 3 and the expansion chamber 4 up to the contact 7; the switch blade is held in the on position by a nose 12, which it behind hooked. The switch blade 11 is in Fig. 1a only partially, namely with its contact tip 11a shown, which has a corresponding bent shaft part 11b is connected to the pivot point B, so that the knife turns on and off along a circular path emotional.

In the pressure chamber 3 are extinguishing plates 10 from heating arranged gas-emitting material, which acts on springs 21 are so that they are pressed against each other. The switch blade 11 moves between them during switching on and off and touch her.

The cutting knife 11 is flat, as the plan views show shaped. Thus the extinguishing chamber meets the requirements regarding the Number of shutdowns for the mentioned services (voltages and current levels), it was necessary that Extend extinguishing chamber volume, which with the invention in compliance the switch dimensions and maintaining the cell grid in Surprisingly simple manner is achieved in that not only the Contact tip 11a dives into the quenching chamber, but at least partly also the switching or cutting blade shaft 11b.

This is the part 9 of the opening 8, so the invention Additional opening allows. During power up, so if that Switching blade 11 is moved to the fixed contact 7, occurs First, the holding part 13 and then the contact tip 11a of the switch blade 11 through the rearward part of the opening 8. Once However, the switch blade 11 reaches the position shown in Fig. 2a, b its stem 11b also enters the chamber area, namely the additional opening 9 of the opening 8, and the further, the further it is the fixed contact 7 approaches.

So that the extinguishing chamber despite the additional opening 9 in the expansion chamber 4 their task, namely the resulting at shutdown Extinguish arc, reliably fulfilled, is the area 9 of the opening 8, so the additional opening in the in Fig. 1a, b shown turned off state by two flaps 14, for example, out Insulant exist, closed. As can be seen in Fig. 1b, the Flaps 14 movably attached to the bottom of the quenching chamber 1, and at the points C. They each have the form of a Circle segment and overlap in the off state the Close the area of the additional opening 9. In a preferred embodiment they are spring-loaded, so that they without an outer, on they acting force, assume the state shown in Fig. 1b. The Extinguishing plates 10 are in the off state to each other.

As soon as the switch is closed by the switch blade 11, So moves to the point B on the fixed contact 7 to and it enters the expansion chamber as described above, meets its shaft 11b sometime, as shown in Fig. 2a, b, on the Flaps 14 and then pushes them against the spring force acting on them apart, so that gradually closed the first Additional opening 9 opens and thus the switch blade 11 in switched state only through the additional opening 9 from the Extinguishing chamber protrudes.

This state is shown in FIGS. 3a, b. The flaps 14 are now completely open, so that they release the additional opening 9. They are from the Schaltmesserschaft 11 a held in this position, while the Switch blade contact tip 11 a presses the quenching plates 10 apart.

When switching off, so if the switch blade 11 from the contact 12 and thus separated from the fixed contact 7, perform switch blades 11 and flaps 14 the reverse movement. The farther the switch blade 11 moves out of the quenching chamber 1, so makes a counter-clockwise rotation about point B, the more it withdraws from the additional opening 9, so that the flaps 14 by the spring force acting on them gradually the assume the starting position shown in FIGS. 1a, b and the opening part Close 9 again.

The additional opening allows for the crescent-shaped switch blade 11, that his trajectory is largely in the quenching chamber 1, so that at the same space requirement for the quenching chamber 1 according to the invention in comparison to known extinguishing chambers a considerably larger chamber volume is achieved.

By depending on the position of the switch blade 11th Moving flaps 14, the deletion of a shutdown resulting arc significantly more efficient. At the time of emergence of the arc, i. when the switch blade 11 just off its closed position (see Fig. 3a, b) from the contact 7 to separate begins, the flaps 14 are open, so that a relatively large amount of oxygen in the Extinguishing chamber 1, in particular in the pressure chamber 3, penetrate can. This is also welcome at the beginning of the deletion process as he the fastest possible formation of the arc from the small one Initial flame calls, so that very quickly caused by the arc Use evaporation process on the extinguishing plates can and the resulting gases now quickly and effectively the arc Clear. The further now the switch blade 11 from the quenching chamber moved out, the more close the flaps 13 and prevent thus on the one hand a further supply of oxygen and on the other hand a leakage of gases from the quenching chamber down, causing too an ionization of the areas between the phases as well as to earth and so that it could lead to flashovers (short circuit). By the Deletion adapted slot opening 8, the extinguishing gases are controlled so that an ionization of the insulating is excluded.

In addition, the initially relatively large and then gradually affects closing additional opening 9 accelerating to the in the pressure chamber 3 resulting extinguishing gases, which is particularly in the low-flow Initial phase by swirling a more efficient cooling and thus causing a more reliable extinguishing of the arc. The closing speed the additional opening 9 can by the shape of the flaps 14 varies and be specially adjusted.

The measures according to the invention thus also increase the efficiency the quenching chamber considerably.

In Figs. 4a, b is another embodiment of an inventive Löschkammer shown, in which the the embodiment according to FIGS. 1 to 3 corresponding parts with the same reference numerals are designated. The embodiment according to FIG. 4a, b differs from the embodiment described above by a another closure mechanism for the additional opening. 9

Instead of the flaps 14 here is a plate or a strip 15 of insulating material used. This or this is at the contact end of the quenching chamber 1 attached at 16 and closes when turned off the switch the complete additional opening 9. When closing the switch blade 11, its shaft presses against the plate or strip 15 the action of a spring 17 in the housing 2 in the direction of the attachment point 16, whereby the additional opening 9 is released. The Operation of this embodiment is the same as before . described According to the position of the switch blade 11 is the additional opening area 9 opened by the plate or the strip 15 or closed. In the pressure chamber 3 are accordingly Extinguishing plates 10 provided from heating material gasabgebendem.

Claims (12)

1. Switch with arc extinguishing chamber (1), in particular for medium voltage load disconnector switches for voltages between 6 and 36 kV, having

   a moveable switch blade (11),

   a pressure chamber (3),

   an expansion chamber (4) and

   a partially closeable opening (8) in the expansion chamber (4),

   characterised in that the partially closeable opening extends over the side (8) and lower (9) part of the expansion chamber (4) and the closeable part of the opening affords a supplementary opening (9) in the lower expansion chamber region, which serves for the passage of the disconnector blade shaft (11b), and the supplementary opening (9) is closed by means of at least one flap (14), which is pivotable around an axis running in substance perpendicularly to the lower wall of the expansion chamber (4), in which the supplementary opening (9) is provided.
2. Switch according to claim 1,
   characterised in that the supplementary opening (9) has the form of a slit.
3. Switch according to claim 1 or 2,
   characterised in that the width of the opening (8, 9) corresponds to the thickness of the disconnector blade (11).
4. Switch according to any of claim 1 to 3,
   characterised by two flaps (14) which overlap upon closure.
5. Switch with arc extinguishing chamber (1), in particular for medium voltage load disconnector switches for voltages between 6 and 36 kV, having

   a moveable switch blade (11),

   a pressure chamber (3),

   an expansion chamber (4) and

   a partially closeable opening (8) in the expansion chamber (4),

   characterised in that the partially closeable opening extends over the side (8) and lower (9) part of the expansion chamber (4) and the closeable part of the opening affords a supplementary opening (9) in the lower expansion chamber region, which serves for the passage of the disconnector blade shaft (11b), and the supplementary opening (9) is closed by means of a plate displaceable along the supplementary opening or a displaceable strip (15).
6. Switch according to any of claims 1 to 5,
   characterised in that the flaps (14) and the plate or the strip (15) are of insulating material.
7. Switch according to any of claims 1 to 6,
   characterised in that the flaps (14) and the plate or the strip (15) are spring loaded.
8. Switch according to any of claims 1 to 7,
   characterised in that in the switched-on condition the supplementary opening (9) is open.
9. Switch according to any of claims 1 to 8,
   characterised in that in the switched-off condition the supplementary opening (9) is closed.
10. Switch according to any of claims 1 to 9,
    characterised in that the flaps (14) and the plate or the strip (15) are actuated by means of the switch blade (11).
11. Switch according to claim 1 to 10,
    characterised by a switch blade (11) moving on a circular path.
12. Switch according to any of claims 1 to 11,
    characterised by spring loaded arc extinguishing plates (10) in the pressure chamber (3).

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