EP2452352B1 - Vacuum switching tube - Google Patents

Description

The invention relates to a vacuum interrupter with a housing which has two with respect to a central plane symmetrically arranged and formed Isolierstoffgehäusebereiche, wherein each of the two Isolierstoffgehäusebereiche comprises a plurality Isolierstoffgehäusebereiche.

Such a vacuum interrupter is from the DE 10029763B4 known. The disclosed there vacuum circuit has a housing which has two with respect to a central plane symmetrically arranged and formed Isolierstoffgehäusebereiche. Each of the two Isolierstoffgehäusebereiche comprises several Isolierstoffgehäuseteile, in the case of DE 10029763B4 two Isolierstoffgehäuseteile are provided in the form of ceramic cylinders for each of the two Isolierstoffgehäusebereiche. The length of each Isolierstoffgehäuseteile is determined by a maximum dielectric load of the vacuum interrupter according to the rated voltage for which the vacuum interrupter is designed and dependent on internal geometry of the vacuum interrupter and capacitive couplings to external conditions, such as a grounded housing of a circuit breaker in which the vacuum interrupter is used. The length of the individual Isolierstoffgehäuseteile is dimensioned so that the vacuum interrupter has the necessary rollover resistance.

Object of the present invention is to develop a vacuum interrupter of the type mentioned, which has a compact design at a high dielectric strength.

This is achieved according to the invention in a vacuum interrupter of the type mentioned above in that the remotest from the center plane Isolierstoffgehäuseteil each Isolierstoffgehäusebereiches has a length which is greater than the length of the other Isolierstoffgehäuseteile.

A greater length of the insulator housing parts of each insulating material housing portion of the vacuum interrupter located farther away from the center plane is advantageous because experience shows that a potential distribution over the vacuum interrupter does not spread linearly over the vacuum interrupter, but the insulating material housing parts arranged away from the center plane experience the greatest stress. This is due to the fact that potential differences per Isolierstoffgehäuseteil steadily increase from one end of the vacuum interrupter to the other end of the vacuum interrupter, so that the last Isolierstoffgehäuseteil experiences the strongest load. In alternating current systems, the polarity of the potentials applied to the tube continues to change, so that the two insulating material housing parts arranged remotely from the center plane of the vacuum interrupter alternately experience the greatest load. The length of these insulator housing parts located farther from the center plane is therefore determined by the required dielectric strength or flashover resistance for which the vacuum interrupter is to be suitable. Further Isolierstoffgehäuseteile, which have a smaller distance to the center plane of the vacuum interrupter, learn a lower dielectric load and thus may have a shorter length, so that with a vacuum interrupter formed in this way a compact construction is possible with a constant high dielectric strength of the vacuum interrupter. Center plane in the sense of the present invention is a plane perpendicular to the longitudinal axis of the vacuum interrupter plane, with respect to which the housing of the vacuum interrupter is formed substantially symmetrical, wherein the housing next to the Isolierstoffgehäuseteilen in known for vacuum interrupters metallic cover parts through which contact terminals for solid contact and moving contact of the vacuum interrupter vacuum-tight therethrough extend into the interior of the vacuum interrupter. The Isolierstoffgehäuseteile are advantageously formed in the form of ceramic cylinders.

In an advantageous embodiment of the invention, the further Isolierstoffgehäuseteile with decreasing distance from the center plane to a decreasing length. Such a decrease in the length of the further Isolierstoffgehäuseteile easily leads to a further compact design of the vacuum interrupter at high dielectric strength, because the dielectric loads with decreasing distance to the center plane of the vacuum interrupter is lower, so that the requirements for the length of Isolierstoffgehäuseteile also lower become.

mit $p\left(x\right)\cong \frac{\left(2x-1\right)}{\left(2N-1\right)}$

und N = Gesamtzahl der Isolierstoffgehäuseteile der Vakuumschaltröhre und $x=N,N-1\dots \frac{N}{2}+1.$

In a particularly advantageous embodiment of the invention, the lengths of the other Isolierstoffgehäuseteile calculated from the length of the remainder arranged Isolierstoffgehäuseteiles according to $$L\left(x\right)\ge p\left(x\right)\cdot L_N$$

With $p\left(x\right)\cong \frac{\left(2x-1\right)}{\left(2N-1\right)}$

and N = total number of insulating housing parts of the vacuum interrupter and $x=N.N-1...\frac{N}{2}+1.$

Such an adjustment of the length of the further Isolierstoffgehäuse by calculation of the length of the remotely located Isolierstoffgehäuseteiles has proven in a variety of experiments and experiments as a best possible adjustment of the length of the other Isolierstoffgehäuseteile depending on the length of the remotely located Isolierstoffgehäuseteils, with the requirements be best met in the dielectric strength and compactness of the vacuum interrupter.

In a further embodiment of the invention, vapor shields and / or field control elements are fastened between the insulating material housing parts. By means of such vapor screens and field control elements, which are mounted between the Isolierstoffgehäuseteilen and are arranged in the interior of the vacuum interrupter, a shielding of Isolierstoffgehäuseteile is ensured in a simple manner by vapor deposition during the switching process resulting metal vapors.

In a further preferred embodiment of the invention, a metallic housing part is provided between the Isolierstoffgehäusebereichen. Such a metallic housing part is also advantageous for increasing the flashover resistance of a vacuum interrupter.

The invention is explained in more detail below with reference to an embodiment with reference to the drawing, the single figure shows a schematic cross-sectional view of a vacuum interrupter according to the invention.

The figure shows a vacuum interrupter 1 with a fixed contact 2 and a fixed contact terminal pin 3 and a moving contact 4 and a Bewegkontaktanschlussbolzen 5. The fixed contact terminal pin 3 is vacuum-tight by a first metallic cover part Led out of the vacuum interrupter, the Bewegkontaktanschlussbolzen 5 is led out by a second metallic cover part 7 by means of a bellows 8 movable vacuum-tight from the vacuum interrupter, so that the contact system of fixed contact 2 and moving contact 4 for switching a guided through the Festkontakt- and Bewegkontaktanschlussbolzen 3 and 5 stream For example, a circuit breaker is formed in which a drive movement of a drive unit, not shown figuratively in the Bewegkontaktanschlussbolzen 5 for closing or opening the contact system of fixed contact 2 and moving contact 4 can be initiated. The vacuum interrupter 1 further comprises housing components in the form of Isolierstoffgehäuseteilen 9, 10, 11 and 12, 13 and 14, which are in the form of ceramic cylinders, wherein between the Isolierstoffgehäuseteilen 11 and 14 in the embodiment, a metallic housing part 15 is provided, which in the area of the contact system of fixed contact 2 and moving contact 4 is arranged. The housing of the vacuum interrupter 1 is constructed and arranged substantially symmetrically with respect to a center plane S, wherein the insulating housing 9, 10 and 11 a first Isolierstoffgehäusebereich 16 and the Isolierstoffgehäuseteile 12, 13 and 14 form a second Isolierstoffgehäusebereich 17, in other words, the Isolierstoffgehäusebereiche 16 and 17 are arranged and formed symmetrically with respect to the center plane S. In this case, symmetrical in the sense of the exemplary embodiment means that the insulating material housing parts 9 and 12 have the same length L ₁ , the insulating housing parts 10 and 13 have the same length L ₂ and the insulating housing parts 11 and 14 have the same length L ₃ and the insulating material housing areas 16 and 17 have the same distance from the center plane S. Between two adjacent Isolierstoffgehäuseteilen and at the border areas between Isolierstoffgehäuseteilen and the first and second metallic cover parts 6 and 7 are provided inside the vacuum interrupter 1 provided vapor shades and / or field control elements 18 to 25 and fixed vacuum-tight. The vapor screens and / or field control elements 18 to 25 serve to shield the Isolierstoffgehäuseteile before vapor deposition with metal vapors produced during a switching operation by burning off of the contacts.

wobei N die Anzahl der Keramiken ist, im Falle des Ausführungsbeispiels 6 und wobei p(x) ein Skalierungsfaktor ist, welcher sich bestimmt aus: $$p\left(x\right)\cdot \cong \left(2x-1\right)/\left(2N-1\right),$$

wobei x die Werte $N,N-1\dots \frac{N}{2}+1$

annehmen kann, so dass im Ausführungsbeispiel der Figur für N = 6 aus Symmetriegründen x die Werte 6, 5 und 4 annehmen und die Längen der Isolierstoffgehäuseteile 9 und 12 sowie 10 und 13 und 11 und 14 jeweils ebenfalls auf Grund der Symmetrie bezüglich der Mittenebene S gleich groß sind, wobei der Skalierungsfaktor
p(6) = 1 = p(1) ist und $p\left(5\right)=p\left(2\right)=\frac{9}{11}$

und $p\left(4\right)=p\left(3\right)=\frac{7}{11}$

ist. Anhand der oben aufgeführten Formel ergibt sich somit für die Länge L₂ = 0,81 * L₁ und für die Länge ${\mathrm{L}}_{\mathrm{3}}=\mathrm{0},\mathrm{64}*{\mathrm{L}}_{\mathrm{1}}\mathrm{.}$

A vacuum interrupter as shown in the embodiment in an AC system undergoes a potential adjustment in the axial direction, wherein the potential distribution increases from one end of the tube to the other end, so that the last ceramic is most heavily loaded. Depending on the polarity, this is in the vacuum interrupter 1, the Isolierstoffgehäussteil 9 and 12, which consequently have the largest length L ₁ , as these are the most distant from the center plane arranged Isolierstoffgehäuseteile each Isolierstoffgehäusebereiches. The length L ₁ is therefore determined by the requirements of the dielectric strength of the vacuum interrupter and the rated voltage and the external conditions such as capacitive coupling to a grounded housing of a surrounding circuit breaker. The length L ₂ or L ₃ of Isolierstoffgehäuseteile 10 and 13 or 11 and 14 is determined by the length L ₁ of Isolierstoffgehäuseteile 9 and 12 according to the formula $$L\left(x\right)\ge p\left(x\right)\cdot L_N.$$

where N is the number of ceramics, in the case of embodiment 6 and where p (x) is a scaling factor which is determined by: $$p\left(x\right)\cdot \cong \left(2x-1\right)/\left(2N-1\right).$$

where x is the values $N.N-1...\frac{N}{2}+1$

assume that in the exemplary embodiment of the figure for N = 6 for reasons of symmetry x the values 6, 5 and 4 and the lengths of Isolierstoffgehäuseteile 9 and 12 and 10 and 13 and 11 and 14 each also due to the symmetry with respect to the center plane S. are the same size, with the scaling factor
p (6) = 1 = p (1) and $\mathrm{<figure-callout\; id="5"\; label="p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">p</figure-callout>}\left(5\right)=p\left(2\right)=\frac{9}{11}$

and $p\left(4\right)=\mathrm{<figure-callout\; id="3"\; label="p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">p</figure-callout>}\left(3\right)=\frac{7}{11}$

is. Based on the formula given above, the length L ₂ = 0.81 * L ₁ and the length are thus obtained ${\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="imgf0001.png"\; state="\{\{state\}\}">L</figure-callout>}}_{\mathrm{3}}=\mathrm{0}.\mathrm{64}*{\mathrm{L}}_{\mathrm{1}}\mathrm{,}$

LIST OF REFERENCE NUMBERS

1

Vacuum interrupter

2

fixed contact

3

Fixed contact terminal stud

4

moving contact

5

Bewegkontaktanschlussbolzen

6

first metallic cover part

7

second metallic cover part

8th

bellow

9 to 14

Isolierstoffgehäuseteile / ceramic cylinder

15

metallic housing part

16

first insulating housing area

17

second Isolierstoffgehäusebereich

18 to 25

Steam screens or field control elements

L ₁

Length of Isolierstoffgehäuseteile 9 and 12th

L ₂

Length of Isolierstoffgehäuseteile 10 and 13

L ₃

Length of Isolierstoffgehäuseteile 11 and 14th

S

Midplane / symmetry axis

Claims (5)

1. Vacuum interrupter (1) having a housing which has two dielectric housing areas (16, 17) which are arranged and formed symmetrically with respect to a center plane (S), with each of the two dielectric housing areas (16, 17) comprising a plurality of dielectric housing parts (9, 10, 11, 12, 13, 14),
   characterized in that
   that dielectric housing part (9, 12) of each dielectric housing area (16, 17) which is arranged furthest away from the center plane (S) has a length (L₁) which is greater than the length (L₂, L₃) of the further dielectric housing parts (10, 11, 13, 14).
2. Vacuum interrupter (1) according to Claim 1,
   characterized in that
   the further dielectric housing parts (10, 11, 13, 14) have a decreasing length (L₂, L₃) as the distance from the center plane (S) decreases.
3. Vacuum interrupter (1) according to Claim 1 or 2,
   characterized in that
   the lengths of the further dielectric housing parts (10, 11, 13, 14) are calculated from the length of the dielectric housing part (9, 12) which is arranged furthest away, using $$L\left(x\right)\ge p\left(x\right)\cdot L_N$$

   

   where $p\left(x\right)\cong \frac{\left(2x-1\right)}{\left(2N-1\right)}$

   

   
   and N = the total number of dielectric housing parts of the vacuum interrupter
   and $x=N,N-1\dots \frac{N}{2}+1.$

   
4. Vacuum interrupter according to one of Claims 1 to 3,
   characterized in that
   vapor shields (18, 19, 20, 21, 22, 23, 24, 25) and/or field control elements (18, 19, 20, 21, 22, 23, 24, 25) are mounted between the dielectric housing parts (9, 10, 11, 12, 13, 14).
5. Vacuum interrupter according to one of the preceding claims,
   characterized in that
   a metallic housing part (15) is provided between the dielectric housing areas (16, 17).

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