DE102020206469B4 - Vacuum interrupter with improved vapor protection - Google Patents

Abstract

Vacuum interrupter (1) for medium-voltage switchgear or high-voltage switchgear with a housing (10), the housing (10) consisting of at least one insulator (15) and a metal part, a contact system (20), the contact system (20) having at least one first contact rod (30 ) with a first contact (35) and a second contact rod (40) with a second contact (45), and at least the first contact rod (30) with the first contact (35) or the second contact rod (40) with the second Contact (45) is designed as a moving contact, at least one shielding element (60), the shielding element (60) being arranged in the insulator (15) in such a way that it surrounds the first contact (35) and the second contact (45), the The first contact rod (30) and/or the second contact rod (40) have a shape that deviates from a cylindrical shape in such a way that metal particles, which arise between the contacts during switching processes, in a collision process with the first contact rod (30) which deviates from the cylindrical shape. and/or the second contact rod (40) are reflected in the direction of the one or more shielding elements (60), wherein the first contact rod (30) and/or the second contact rod (40), which deviate from the cylindrical shape, at least in sections taper in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45), characterized in that the first contact rod (30) and/or the second contact rod (40) have the cylindrical shape deviate, extends out over a first section (110), which is located within the shielding element (60) or the shielding elements (60), or - the first contact rod (30) and / or the second contact rod (40), which are from the deviate from a cylindrical shape, each having two or more second sections (120), the first contact rod (30) which deviates from the cylindrical shape and/or the second contact rod (40) which deviates from the cylindrical shape being located in the respective second section (120 ) taper in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45), and between adjacent second sections (120) a diameter (150) tapers in the direction of the respectively assigned first contact (35). and/or the respectively assigned second contact (45) is enlarged.

Description

The invention relates to a vacuum interrupter with improved vapor protection.

In conventional vacuum interrupters, metal vapor is released during switching operations. The metal particles formed in this way settled on the surrounding components in the vacuum interrupter. Such vapor deposition always becomes problematic when insulator parts, in particular ceramic parts of the vacuum interrupter, are affected, i.e. metal particles accumulate on the ceramic, i.e. the ceramics are vapor-deposited with metal. Such metal vapor deposition changes, in particular reduces, insulation distances, which is why the vapor deposition of insulator parts, in particular ceramic parts, is problematic and should be avoided.

From the US 2006/0081560 A1 is now a switching tube with contact rods that thicken outwards on the opposite sides and which has a shielding element around the contacts, a bellows shield.

The prior art therefore uses complex, nested shield arrangements that are expensive and problematic to handle when constructing a vacuum interrupter.

The task is now to provide a vacuum interrupter with improved vapor protection, which is less complex in design and structure and cheaper.

The task is solved by the independent claim 1 and the claims dependent on it.

• - einem Gehäuse, wobei das Gehäuse aus mindestens einem Isolator und einem Metallteil besteht,
• - einem Kontaktsystem, wobei das Kontaktsystem zumindest einen ersten Kontaktstab mit einem ersten Kontakt und einen zweiten Kontaktstab mit einem zweiten Kontakt aufweist, und wobei der erste Kontaktstab mit dem ersten Kontakt und/oder der zweite Kontaktstab mit dem zweiten Kontakt als Bewegkontakt ausgeführt ist,
• - mindestens einem Schirmelement, wobei das Schirmelement in dem Isolator derart angeordnet ist, dass es den ersten Kontakt und den zweiten Kontakt umgibt, wobei

der erste Kontaktstab und/oder der zweite Kontaktstab eine von einer zylindrischen Form derart abweichende Form aufweisen, dass Metallteilchen, die bei Schaltprozessen zwischen den Kontakten entstehen, bei einem Stoßprozess mit dem von der zylindrischen Form abweichenden ersten Kontaktstab und/oder dem zweiten Kontaktstab in Richtung des Schirmelementes reflektiert werden, wobei sich der erste Kontaktstab und/oder der zweite Kontaktstab, die von der zylindrischen Form abweichen, zumindest abschnittsweise in Richtung des jeweils zugeordneten ersten Kontaktes und/oder des jeweils zugeordneten zweiten Kontaktes hin verjüngen.The exemplary embodiment relates to a vacuum interrupter for medium-voltage switchgear or high-voltage switchgear

• - a housing, the housing consisting of at least one insulator and a metal part,
• - a contact system, wherein the contact system has at least a first contact rod with a first contact and a second contact rod with a second contact, and wherein the first contact rod with the first contact and / or the second contact rod with the second contact is designed as a moving contact,
• - at least one shielding element, the shielding element being arranged in the insulator such that it surrounds the first contact and the second contact, wherein

the first contact rod and/or the second contact rod have a shape that deviates from a cylindrical shape in such a way that metal particles that arise between the contacts during switching processes move in the direction of the first contact rod and/or the second contact rod that deviate from the cylindrical shape during a collision process of the shield element are reflected, wherein the first contact rod and / or the second contact rod, which deviate from the cylindrical shape, taper at least in sections in the direction of the respectively assigned first contact and / or the respectively assigned second contact.

A first alternative is characterized in that the first contact bar and/or the second contact bar, which deviate from the cylindrical shape, extends out over a first section which is located within the shield element(s). It is not relevant whether one shielding element or several shielding elements surround the first contact and the second contact.

A second alternative is characterized in that the first contact rod and/or the second contact rod, which deviate from the cylindrical shape, each have two or more second sections, with the first contact rod deviating from the cylindrical shape and/or the one from the Second contact rod, which deviates from a cylindrical shape, tapers in the respective second section in the direction of the respectively assigned first contact and / or the respectively assigned second contact, and between each adjacent second sections a diameter of the respective contact rod, i.e. the first contact rod or second contact rod, in Enlarged towards the respectively assigned first contact and/or the respectively assigned second contact. Such an arrangement creates a sawtooth-like structure on the respective contact rod in the longitudinal section.

Tapering here means that a diameter of the first contact rod and/or the second contact rod decreases, in particular here it decreases like a truncated cone in the direction of the respective first contact or second contact.

Since the mean free path for the metal particles is relatively long in a vacuum, the metal particles, i.e. the particles of the metal vapor and/or the plasma, spread almost in a straight line until they are reflected or absorbed by components in the vacuum interrupter. Due to the contact rod(s) that deviate from the cylindrical shape and are tapered in the direction of the contacts, metal particles increasingly collide with the shield element(s). Through the increased The number of impacts with the first contact rod or second contact rod and the shielding element(s) increases the probability of absorption of the metal particles, i.e. metal particles from a metal vapor or plasma, on one of the metal parts, so that vapor deposition of insulator parts, in particular ceramic parts, is reduced without nesting , complex shield structures are required. Here and in the following, reflecting means that metal particles that hit a surface, in particular a metal surface, in their linear movement away from the contacts, interact with this surface, collide, and, depending on their angle of incidence, move away from the surface again, again as far as possible linear movement.

It is preferred that the contact system consists of a moving contact and a fixed contact. The moving contact rod or the fixed contact rod or both can have the deviation from the cylindrical shape described above.

It is further preferred that the diameter between adjacent second sections increases suddenly in the direction of the respectively assigned first contact and/or the respectively assigned second contact. In particular, abruptly means here that the diameter increases perpendicular to the longitudinal axis of the respective contact rod in one step.

It is also preferred that the first contact rod and/or the second contact rod, which deviate from the cylindrical shape, each have a plurality of second sections. As a result, a small increase in the diameter of the respective contact rod is sufficient to reflect metal particles onto the shield element or elements.

It is also preferred that the first contact rod and/or the second contact rod, which deviate from the cylindrical shape, each have a plurality of second sections in the form of grooves, that is to say that ring-shaped depressions are arranged on the respective contact rod, the depressions become deeper in the direction of the respective first and/or second contact, i.e. have a “sloping bottom” and on the one hand reflect the metal particles in the direction of the shield element or elements and also serve as a metal particle trap.

It is further preferred that the first contact bar and/or the second contact bar are made of copper or contain copper. Alternatively, stainless steel, aluminum, an aluminum alloy, other metals or other metal alloys are also possible.

It is also preferred that the areas of the first contact rod and/or the second contact rod that deviate from the cylindrical shape are formed by sheets arranged on a first contact rod and/or second contact rod with a cylindrical shape with sheets arranged on the first contact rod and/or second contact rod .

In particular, it is preferred that the sheets are pushed onto the respective first contact bar and/or second contact bar and are fastened there.

• 1: Schematische Darstellung eines Kontaktsystem einer Vakuumschaltröhre aus dem Stand der Technik im Schnitt;
• 2: Schematische Darstellung eines erfindungsgemäßen Kontaktsystem einer Vakuumschaltröhre im Schnitt;
• 3: Schematische Darstellung eines erfindungsgemäßen Kontaktsystem einer Vakuumschaltröhre im Schnitt.

The invention is explained below with reference to figures.

• 1 : Schematic representation of a contact system of a vacuum interrupter from the prior art in section;
• 2 : Schematic representation of a contact system according to the invention of a vacuum interrupter in section;
• 3 : Schematic representation of a contact system according to the invention of a vacuum interrupter in section.

The 1 shows a part of a section through a vacuum interrupter from the prior art. The vacuum interrupter has a housing 10 with at least one insulator 15 and one or more metal parts, not shown. A contact system 20 is arranged in the housing 10 and consists of at least a first contact rod 31 with a first contact 36 and a second contact rod 41 with a first contact 46. In addition, other components not shown here can also be part of the contact system, such as a Contact carriers, stabilization elements and/or others. A shielding element 60 is arranged in the vacuum interrupter around the contacts 36, 46 of the contact system 20.

During switching operations, a metal vapor or plasma 201 can arise between the first contact 31 and the second contact 41. Due to the long mean free path in the vacuum, metal particles from the metal vapor 201 move largely linearly between the components of the vacuum interrupter. The metal particles collide with the metal parts of the vacuum interrupter and are reflected there almost analogously to the optics, that is, according to the angle of incidence, the metal particles move away from the metal surfaces again, unless the metal particles are absorbed on the metal surfaces, absorbed here means the metal particles stick to the metal surface. An exemplary path with several The reflection is shown by line 200. Since the path 200 of the metal particle ends here on the insulator, vaporization of the insulator would occur, which should be avoided.

The 2 now shows part of a section through a vacuum interrupter according to the invention. The vacuum interrupter has a housing 10 with at least one insulator 15 and one or more metal parts, not shown, such as caps or bushings. A contact system 20 is arranged in the housing 10 and consists of at least a first contact rod 30 with a first contact 35 and a second contact rod 40 with a first contact 45. In addition, other components not shown here can also be part of the contact system, such as a Contact carriers, stabilization elements and/or others. A shielding element 60 is arranged in the vacuum interrupter around the contacts 35, 45 of the contact system 20. The screen element 60 can consist of one screen element, as shown here, or of several screen elements, as not shown.

During switching operations, a metal vapor or plasma 201 can arise between the first contact 30 and the second contact 40. Due to the long mean free path in the vacuum, metal particles from the metal vapor 201 move largely linearly between the components of the vacuum interrupter. The metal particles collide with the metal parts of the vacuum interrupter and are reflected there almost analogously to the optics, that is, according to the angle of incidence, the metal particles move away from the metal surfaces again, unless the metal particles are absorbed on the metal surfaces, absorbed here means the metal particles stick to the metal surface. An exemplary multiple reflection path is represented by line 210. Since the path 210 of the metal particle ends here on the shielding element 60, the metal particle is absorbed on the shielding element 60. This route 210 is different from route 200 1 because of the surface 32, 42 of the first contact rod 30 and second contact rod 40 which is tilted relative to the longitudinal axis 100 of the first contact rod 30 and second contact rod 40. The surfaces 32, 42 are inclined towards the first contact 35 and second contact, that is to say the diameter 150 of the first contact rod 30 and second contact rod 40 decreases in the direction of the first contact 35 and second contact 45. Alternatively, only the first contact rod 30 or the second contact rod 40 can be designed to converge, conically.

In the 2 a linear reduction in diameter 150 is shown. However, the reduction can have a different functional connection, such as parabolic, circular, single or multi-curved.

Here it is shown by way of example that the first contact rod 30 and the second contact rod 40, which deviate from the cylindrical shape, extend out over a first section 110 which is located within the shield element 60.

The dashed line 43 indicates an alternative embodiment in which the surface 42 can also be created by a pushed-on sheet metal and thus material can be saved on the contact rod.

The 3 shows part of a section through an alternative vacuum interrupter according to the invention. The vacuum interrupter has a housing 10 with at least one insulator 15 and one or more metal parts, not shown, such as caps or bushings. A contact system 20 is arranged in the housing 10 and consists of at least a first contact rod 30 with a first contact 35 and a second contact rod 40 with a first contact 45. In addition, other components not shown here can also be part of the contact system, such as a Contact carriers, stabilization elements and/or others. A shielding element 60 is arranged in the vacuum interrupter around the contacts 35, 45 of the contact system 20. The screen element 60 can consist of one screen element, as shown here, or of several screen elements, as not shown.

During switching operations, a metal vapor or plasma 201 can arise between the first contact 30 and the second contact 40. Due to the long mean free path in the vacuum, metal particles from the metal vapor 201 move largely linearly between the components of the vacuum interrupter. The metal particles collide with the metal parts of the vacuum interrupter and are reflected there almost analogously to the optics, that is, according to the angle of incidence, the metal particles move away from the metal surfaces again, unless the metal particles are absorbed on the metal surfaces, absorbed here means the metal particles stick to the metal surface. An exemplary multiple reflection path is shown by line 220. Since the path 220 of the metal particle ends here on the shielding element 60, the metal particle is absorbed on the shielding element 60. This route 220 is different from route 200 1 because of the surface 32, 42 of the first contact rod 30 and second contact rod 40, which is tilted several times relative to the longitudinal axis 100 of the first contact rod 30 and second contact rod 40. The surfaces 32, 42 are inclined towards the first contact 35 and second contact, that is to say the Diameter 150 of the first contact rod 30 and second contact rod 40 decreases in the direction of the first contact 35 and second contact 45 in the second sections 120. In contrast to 2 However, the diameter 150 does not decrease steadily in the direction of the first contact 30 and the second contact 40, but rather the diameter decreases in a second section 120 and then increases again suddenly between two sections 120, here for example to the initial size of the diameter 150 to enlarge. This gives you the section view 3 a sawtooth-like arrangement. This has the advantage over the arrangement of the 2 that the largest diameter 150 of the first contact rod 30 and / or second contact rod 40 can be chosen smaller and thus material savings are possible. Alternatively, only the first contact rod 30 or the second contact rod 40 can be designed to converge in a sawtooth-like manner.

In the 3 a linear reduction in the diameter 150 is shown in the respective sections 120. However, the reduction can have a different functional connection, such as parabolic, circular, single or multi-curved.

Reference symbol list

1

vacuum interrupter

10

Housing;

15

Insulator;

20

contact system;

30

first contact rod;

31

first prior art contact rod;

35

first contact;

36

first contact with the prior art;

40

second contact rod;

41

second contact rod from the prior art;

45

second contact;

46

second contact from the prior art;

60

umbrella element;

110

first section;

120

two section;

200

Exemplary path of a metal particle from the metal vapor 201;

201

metal vapor/plasma;

210

Exemplary path of a metal particle from the metal vapor 201;

220

Exemplary path of a metal particle from the metal vapor 201;

Claims (8)

Vacuum interrupter (1) for medium-voltage switchgear or high-voltage switchgear with a housing (10), the housing (10) consisting of at least one insulator (15) and a metal part, a contact system (20), the contact system (20) having at least one first contact rod ( 30) with a first contact (35) and a second contact rod (40) with a second contact (45), and at least the first contact rod (30) with the first contact (35) or the second contact rod (40) with the second contact (45) is designed as a moving contact, at least one shielding element (60), the shielding element (60) being arranged in the insulator (15) in such a way that it surrounds the first contact (35) and the second contact (45), wherein the first contact rod (30) and/or the second contact rod (40) have a shape that deviates from a cylindrical shape in such a way that metal particles that arise between the contacts during switching processes, in a collision process with the first contact rod (which deviates from the cylindrical shape) 30) and/or the second contact rod (40) are reflected in the direction of the one or more shielding elements (60), wherein the first contact rod (30) and/or the second contact rod (40), which deviate from the cylindrical shape, taper at least in sections in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45), characterized in that - the first contact rod (30) and/or the second contact rod (40), which are provided by the deviate from a cylindrical shape, extends out over a first section (110), which is located within the shielding element (60) or the shielding elements (60), or - the first contact rod (30) and / or the second contact rod (40), which deviate from the cylindrical shape, each have two or more second sections (120), the first contact rod (30) deviating from the cylindrical shape and/or the second contact rod (40) deviating from the cylindrical shape being located in the respective second section (120) taper in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45), and border between each other At the ends of the second sections (120), a diameter (150) increases in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45). Vacuum interrupter (1). Claim 1 , characterized in that the contact system (20) consists of a moving contact and a fixed contact. Vacuum interrupter (1). Claim 1 second alternative or Claim 2 , characterized in that the diameter (150) between adjacent second sections (120) increases suddenly in the direction of the respectively assigned first contact (35) and/or the respectively assigned second contact (45). Vacuum interrupter (1). Claim 1 or 3 , characterized in that the first contact rod (30) and / or the second contact rod (40), which deviate from the cylindrical shape, each have a plurality of second sections (120). Vacuum interrupter (1). Claim 4 , characterized in that the first contact rod (30) and / or the second contact rod (40), which deviate from the cylindrical shape, each have a plurality of second sections (120) in the form of grooves. Vacuum interrupter (1) according to one of the preceding claims, characterized in that the first contact rod (30) and/or the second contact rod (40) are made of copper or contain copper. Vacuum interrupter according to one of the preceding claims, characterized in that the areas of the first contact rod (30) and/or the second contact rod (40) which deviate from the cylindrical shape are applied to a first contact rod (31) and/or a second contact rod ( 41) with a cylindrical shape are formed with sheets arranged on the first contact rod (31) and / or second contact rod (41). vacuum interrupter Claim 7 , characterized in that the sheets are pushed onto the respective first contact rod (30) and/or second contact rod (40) and are fastened there.

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