Arrangement for switching high voltages with vacuum interrupter and method for its manufacture

Abstract

The invention relates to an arrangement (1) for switching high voltages and a method for producing the same, comprising a vacuum interrupter (2) comprising at least one movable contact piece (4) in a housing (5) and at least one bellows (6), and comprising a rod (7) for moving the at least one movable contact piece (4). The rod (7) is reinforced by a bar (8) at least in the region of the bellows (6).

Description

[0001] The invention relates to an arrangement for switching high voltages and a method for manufacturing them, comprising a vacuum switching tube which includes at least one movable contact piece in a housing and at least one bellows, and a rod for moving the at least one movable contact piece.

[0002] Arrangements for switching high voltages with vacuum interrupters or vacuum switches are used, for example, in circuit breakers, where switching contacts or contact pieces that are movable relative to each other are arranged in at least one vacuum interrupter. In high-voltage engineering, such vacuum interrupters are used for switching voltages in the high-voltage range, especially greater than or equal to 52 kV, and / or for switching large currents in the range of up to several tens of kiloamperes. Vacuum interrupters, especially those included in switching arrangements, require little maintenance, are durable, and are driven simply and reliably, particularly by spring-loaded actuators and / or motors. For high voltage requirements, arrangements with several vacuum interrupters are used, whose switching sections are electrically connected in series, as is known, for example, from DE 10 2013 208 419 A1. Alternatively, for example,Vacuum switching tubes with multiple switching sections are used, in particular in a vacuum switching tube.

[0003] For switching, the movable switching contacts are in mechanical and electrical contact when switched on, and are moved away from each other to switch off. In the off state, a gap is formed between the contacts, with a gap width ranging from millimeters to centimeters. The vacuum created in the vacuum switching tube between the contacts maintains a voltage, up to high voltage, without electrical discharges, such as arcing, when switched off. To switch on, the movable contacts are moved towards each other until electrical and mechanical contact is established.

[0004] To isolate the contacts from each other when the device is off, a vacuum is maintained within the vacuum switching tube, and the tube's housing includes insulating sections, such as one or more ceramic segments. For good electrical conductivity when switched on, the contacts are made of a metal or metal alloy. Good electrical conductivity is achieved, for example, by using copper contacts. Often, one fixed and one movable contact are used for simplicity, as this requires only one actuator to move one contact during switching. The fixed contact is vacuum-tight and mechanically secured at one end of the vacuum switching tube, for example, via a metal cap. The movable contact is located at the opposite end of the vacuum switching tube, for example, via a metal cap.A metallic lid with a bellows is vacuum-tight and mechanically movable and is inserted into the vacuum switching tube.

[0005] During switching, the movable contact is driven by a mechanism, particularly a spring-loaded actuator and / or motor, with power transmission via elements of a kinematic chain, such as gears and a drive rod. Depending on the weight of the movable contact, a certain force and / or energy is required to drive it. With a larger mass of the movable contact, the necessary force and / or energy, as well as the switching time, increases. To achieve good switching kinematics, the mass of the movable contact must be reduced. This is achieved, for example, by making the contact hollow internally, which leads to reduced mechanical stability and a lower current-carrying capacity. During switching, especially during contact bounce, deformation of the movable contact is possible, potentially leading to irreversible damage.

[0006] The invention is based on the objective of providing an arrangement for switching high voltages and a method for its manufacture, which solves the problems described above. In particular, it is an objective of the present invention to provide an arrangement with a vacuum switching tube that is permanently mechanically stable, even at high drive speeds or strong contact bounce, that has a high current-carrying capacity, and that exhibits low heat generation at high currents. The method is intended to enable soldering at high temperatures.

[0007] The object of the invention is achieved by an arrangement for switching high voltages with the features of claim 1 and / or by a method for manufacturing the arrangement according to claim 13. Advantageous embodiments of the arrangement for switching high voltages according to the invention are specified in the dependent claims. The subject matter of the main claim can be combined with features of the dependent claims, and features of the dependent claims can be combined with each other.

[0008] An arrangement according to the invention for switching high voltages comprises a vacuum switching tube, which includes at least one movable contact in a housing and at least one bellows, and a rod for moving the at least one movable contact. At least in the region of the bellows, the rod is reinforced by a bar. Reinforcing the rod with a bar increases the mechanical stability in this region, particularly in the region of the bellows, so that the vacuum switching tube remains mechanically stable even at high drive speeds or with strong contact bounce between the movable contact and, for example, a fixed contact or a second movable contact. The reinforcement enables a high current-carrying capacity towards the movable contact.across the vacuum switching tube in the switched-on state and reduces heat generation at high currents by increasing the cross-sectional area of ​​conductive areas towards the movable contact piece and thus reducing the electrical resistance across the vacuum switching tube in the switched-on state.

[0009] The rod can be hollow and cylindrical, particularly with a circular cross-sectional area. This allows the rod to spatially encompass the connecting rod, especially in a region along a common longitudinal axis, thus enabling a compact design of the vacuum switching tube.

[0010] The at least one movable contact piece can be fluid-tightly attached to the at least one bellows, in particular by soldering, and / or the at least one movable contact piece can be arranged exclusively in the interior of the housing, in particular in an evacuated state. The rod, reinforced by the bar, can connect to the movable contact piece on the outside or be mechanically stable and / or conductively attached to it. In the case of a bellows that projects into the vacuum switching tube and seals it vacuum-tight to the outside, and with a movable contact piece that is fluid-tightly attached to the at least one bellows, in particular by soldering, and with the at least one movable contact piece that is arranged exclusively in the interior of the housing, in particular in an evacuated state, the rod with bar is arranged at least in the area of ​​the bellows.The tube is spatially enclosed at least partially along its longitudinal axis, particularly around the circumference of the rod along the length of the bellows. This allows the vacuum switching tube to be manufactured and soldered without the rod and bar, whereby, after soldering, the rod, especially with the bar attached, can be fixed to the movable contact piece. This prevents the rod and bar from being exposed to the soldering temperatures, and allows the use of materials for the rod and bar that are, for example, less expensive than copper for the movable contact piece and / or have higher conductivity and / or higher mechanical strength. Alternatively, the rod can be attached to or soldered to the movable contact piece during the soldering process, or even be formed with the contact piece. In this case, only the rod is subsequently attached to the rod after soldering. The advantages, as described above, relate to the rod.

[0011] The at least one movable contact piece can be made of copper or comprise copper. The rod can be made of copper, steel, plastic, or glass fiber reinforced plastic. The bar can be made of copper, aluminum, plastic, or glass fiber reinforced plastic. A movable copper contact piece allows for high electrical conductivity, particularly in the vacuum switching tube, with low electrical resistance and consequently low heat generation at high currents. Copper is stable at the temperatures of a soldering process during the manufacture of the vacuum switching tube. For similar reasons, the rod and bar can be made of copper. Since the rod and / or bar can be attached to the movable contact piece after the soldering process, materials that are not stable at soldering temperatures can also be used for the rod and / or bar. For example,Plastics or aluminum can be damaged or destroyed at soldering temperatures, affecting their shape and / or structure. Copper, however, is expensive and heavy, requiring high forces and costly drives for switching, resulting in slower switching with lower acceleration for the same force compared to lighter materials. Aluminum, plastics, and glass fiber reinforced plastics are lighter than copper, allowing the use of smaller, more cost-effective drives, particularly spring-loaded actuators, and enabling higher accelerations and thus faster switching for the same force.

[0012] The use of a rod with a connecting rod allows for material combinations that offer favorable properties for electrical conductivity and mechanical stability at a low mass. For example, a copper rod with an aluminum connecting rod, or a steel rod with an aluminum connecting rod, provides high mechanical stability along the connecting rod, good conductivity across the connecting rod and / or the connecting rod, and reduced weight due to the connecting rod, offering the advantages described above. Weight reduction is also possible, for example, by using plastics and / or fiber-reinforced plastics as materials for the connecting rod or the connecting rod. Electrical conduction then occurs via the connecting rod or connecting rod, which may be made of copper, aluminum, or steel, for example.

[0013] The at least one movable contact can be made of copper, and the rod can be made of aluminum, or copper or steel. A copper contact offers good electrical conductivity, meaning it has low electrical resistance and therefore generates little heat, even at high currents. When soldering the assembly, for example in a furnace, materials such as copper and steel remain stable at soldering temperatures. An aluminum rod is lighter than a copper rod, while still offering good electrical conductivity and the advantages described above. The lighter weight reduces the forces required for switching, allowing the use of less powerful actuators, such as spring-loaded actuators and / or motors, thus saving costs.A lower weight allows for greater acceleration of the moving contact during switching, especially with the same force, resulting in faster switching and consequently shorter switching times. The rod mechanically reinforces the contact, thus increasing its mechanical stability, and, if a conductive material is used for the rod, it can improve electrical conductivity to the moving contact. A disadvantage of aluminum is that it can be irreversibly damaged or destroyed at soldering temperatures. A rod made of copper or steel offers high mechanical stability and good electrical conductivity.

[0014] The rod can be screwed into the at least one movable contact piece at one end. This allows the rod to be attached to the at least one movable contact piece after the soldering process. This prevents damage or destruction during soldering and enables the use of materials such as aluminum for the rod. The rod can be attached to the main rod at one end via a nut. This results in a stable mechanical and, in particular, electrical connection between the rod and the main rod. Alternatively or additionally, the rod can be glued, soldered, welded, screwed, and / or clamped to the main rod and / or the movable contact piece.

[0015] The rod can be designed in the form of a sleeve and, in particular, can form-fittingly surround a portion of the rod, especially in the area of ​​the bellows. This allows the rod to compactly enclose the rod and reinforce it mechanically and / or electrically, i.e., with regard to its current-carrying capacity.

[0016] The length of the rod can essentially correspond to the length of the bellows when the vacuum switching tube is switched on. This allows the rod to be mechanically and / or electrically reinforced in the area of ​​the bellows, thus providing a mechanically stable bridge across the gap.

[0017] The vacuum switching tube can comprise at least one fixed contact element, in particular arranged along a common longitudinal axis opposite the at least one movable contact element, and / or at least partially arranged in the housing. This allows the vacuum switching tube to be switched by a drive, e.g., a spring-loaded drive and / or a motor, wherein the switching movement or force of the drive is transmitted to the at least one movable contact element via elements of a kinematic chain, e.g., gear parts, the rod, and / or the connecting rod.

[0018] The housing of the vacuum switching tube can comprise at least one ceramic hollow cylinder, in particular fluid-tightly sealed at the ends by metal caps, contacts, and at least one bellows. The vacuum switching tube is evacuated inside. The vacuum switching tube is, for example, soldered to create a fluid-tight seal, and then the rod can be attached. The rod can be attached to the at least one contact during soldering or afterward. The latter allows the use of materials, such as plastic or GRP (glass fiber reinforced plastic), or aluminum for the rod, which cannot withstand high temperatures, such as those encountered during soldering, without damage. An electrical connection can be made via the rod to the at least one movable contact, and / or the electrical resistance to the at least one movable contact can be reduced via the rod, for example.Using a conductor such as aluminum for the rod results in reduced weight compared to using a reinforced rod, e.g., made of copper. Furthermore, the rod increases the mechanical stability of the rod within the kinematic chain.

[0019] The vacuum switching tube can be configured to switch voltages in the high-voltage range, particularly in the range of 52 kV or greater. It can also switch high currents, especially up to 100 amperes. The advantages of the rod described above are thus advantageously utilized.

[0020] A method according to the invention for manufacturing a previously described arrangement comprises sealing the vacuum switching tube, in particular with the movable contact piece and the at least one bellows, fluid-tight by soldering, and in a subsequent step connecting the rod and the bar to the movable contact piece, in particular via a nut, especially by screwing. The advantages are as described above.

[0021] An embodiment of the invention is shown schematically in the single figure below and described in more detail below.

[0022] This shows Figure schematically in sectional view of an arrangement 1 according to the invention for switching high voltages, with a vacuum switching tube 2 which comprises a movable contact piece 4 in a housing, and with a rod 7 for moving the at least one movable contact piece 4, which is reinforced by a rod 8.

[0023] In Fig.Figure 1 schematically illustrates an arrangement 1 according to the invention for switching high voltages with a vacuum switching tube 2. The vacuum switching tube 1 comprises at least one fixed and one movable contact element 3 and 4, which are at least partially arranged in a housing 5, and at least one bellows 6, via which the movable contact element 4 is movably mounted in the housing 5 and / or to which the movable contact element 4 is fluid-tightly attached. A rod 7 is arranged on the movable contact element 4 for moving the at least one movable contact element 4, for example, via a drive, in particular a spring-loaded drive and / or motor. For the sake of simplicity, the drive is not shown in the single figure.

[0024] At least in the area of ​​the bellows 6, the rod 7 is reinforced by a rod 8. In this context, "in the area of ​​the bellows 6" means along the length of the bellows 6 when the vacuum switching tube 2 is switched on, with the contact pieces 3 and 4 in mechanical and / or electrical contact with each other. The rod 8 is, for example, hollow cylindrical and surrounds the rod 7 spatially, in particular analogous to a sleeve around the rod 7, e.g., in a form-fitting manner. The rod 7 is attached to the movable contact piece 4, e.g., screwed and / or clamped and / or welded, glued, and / or soldered to the contact piece 4. The rod 8 is, for example, B. analogous to a sleeve pulled or slipped over the rod 8, and screwed onto the rod 7 on the opposite side to the side of the movable contact piece 4 via a nut, i.e. clamped between the movable contact piece 4 and the nut 9.Alternatively or additionally, the rod can also be pressed, glued, welded, soldered and / or screwed onto the rod 7.

[0025] The movable contact piece 4 is, for example, made of copper, aluminum, and / or steel, or comprises copper, aluminum, and / or steel, and the bellows 6 is, for example, made of steel. The rod 7 is part of a kinematic chain for driving the movable contact piece 4 when switching the vacuum switching tube 2. Kinetic energy or a force generated by a drive, e.g., a spring-loaded drive and / or motor, and transmitted via elements of the kinematic chain, e.g., via gear parts, rods, and / or couplings, is transferred to the movable contact piece 4 via the rod 7. Large forces result in significant mechanical stress on the rod 7. To prevent damage, up to and including irreversible destruction of the contact piece 4, the rod 8 mechanically reinforces it. At high currents, the rod 8 can electrically assist the rod 7.This allows current to flow through rod 8, thereby reducing its resistance, depending on the material chosen. This reduces the heating of rod 7 and the thermal stress. Damage from high temperatures can be avoided, and electrical losses through the vacuum switching tube can be minimized.

[0026] Rod 7 is made of copper and / or steel, for example, and rod 8 is made of aluminum. This results in a weight reduction compared to a thicker rod 7, while maintaining high current-carrying capacity and mechanical stability, thanks to the reinforcement of rod 7 by rod 8. The reduced weight enables faster switching, i.e., higher switching speeds, and / or the use of smaller actuators, as less force is required for switching, thus saving costs on more complex actuators.

[0027] The housing 5 comprises at least one ceramic hollow cylinder 10, each end of which is sealed fluid-tight or vacuum-tight by metal caps 11. The metal caps 11 are, for example, made of steel. On one side, the fixed contact piece 3 is guided vacuum-tight through the respective metal cap 11. The fixed contact piece 3 is, for example, made of copper and / or comprises copper and / or steel. On the opposite side of the housing 5, the movable contact piece 4 is movably mounted via the bellows 6, the bellows 6 being attached to the respective metal cap 11 on this side. The metal cap 11 is vacuum-tight connected to the bellows 6, and the movable contact piece 4 is vacuum-tight connected to the bellows. The connection of the parts of the vacuum switching tube 2, in particular the ceramic hollow cylinder 10, the metal caps 11, the bellows 6 and the contact pieces 3 and 4, is carried out, for example, by soldering in a soldering oven.

[0028] Adding less temperature-resistant materials, such as an aluminum rod 8, after the soldering process allows the use of materials like aluminum in arrangements 1 with vacuum-tight soldered vacuum switching tubes 2. The advantages described above can be realized in this way, particularly with a movable contact element of minimal size. The contact element 4 is vacuum-tight and movably attached at one end to the end of the bellows 6. Alternatively, longer contact elements 4 can be used, which are spatially enclosed by the bellows 6, i.e., passed through or within the bellows 6.

[0029] The embodiments described above can be combined with one another and / or with the prior art. For example, the ceramic hollow cylinder 10 can be designed in a segmented form. Metal screens, in particular vapor screens, and at least one metallic switching chamber can be provided, enclosed by the vacuum switching tube 2. More than one fixed and / or movable contact element 3, 4 can be used. The contact elements can be designed in one piece or in multiple parts, e.g., with a copper shaft and a steel-reinforced copper plate.

[0030] The rod and / or bar can comprise or be made of lightweight materials. For example, aluminum, electrically conductive or insulating plastics, and / or fiberglass-reinforced plastics can be used. The rod or bar can provide only mechanical support if it is made of an insulator, while the other part, e.g., the rod or bar, can be conductive and carry the current when energized. Alternatively, the rod and bar can be made of conductive materials, with the bar providing mechanical and electrical reinforcement. Electrical conduction can also occur via the bellows, particularly a steel bellows.

[0031] The metal caps 11 are made of metals such as steel, aluminum, or copper. Alternatively, plastic caps or other materials, such as ceramics, can be used to seal the ends of the vacuum switching tube 2. The vacuum switching tube 2 can be electrically connected, in particular by components such as capacitors, resistors, coils, varistors, and / or surge arresters, e.g., along the outer circumference and longitudinal axis of the vacuum switching tube 2, directly on the housing 5 or at a distance from the housing 5, or in a separate housing, for controlling the vacuum switching tube 2. This allows for a predetermined, in particular uniform, voltage drop along the longitudinal axis of the vacuum switching tube 2 when the device is switched off and a voltage is applied. Reference symbol list 1. Arrangement for switching high voltages 2 vacuum switching tubes 3 fixed contact piece 4 movable contact pieces 5 cases 6 bellows 7 Rod for moving the movable contact piece 8 bars 9 Mother 10 ceramic hollow cylinders 11 metal caps QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2013 208 419 A1

[0002]

Claims

[1] Arrangement (1) for switching high voltages, comprising a vacuum switching tube (2) which includes at least one movable contact piece (4) in a housing (5) and at least one bellows (6), and a rod (7) for moving the at least one movable contact piece (4), characterized by , that at least in the area of ​​the bellows (6) the rod (7) is reinforced by a rod (8). [2] Arrangement (1) according to claim 1, characterized by , that the rod (8) is hollow cylindrical, in particular with a circular cross-sectional area. [3] Arrangement (1) according to any one of the preceding claims, characterized by that the rod (8) spatially encompasses the pole (7), in particular in an area along a longitudinal axis, in particular a common one. [4] Arrangement (1) according to any one of the preceding claims, characterized by, that the at least one movable contact piece (4) is fluid-tightly attached to the at least one bellows (6), in particular soldered, and / or that the at least one movable contact piece (4) is arranged exclusively in the interior of the housing (5), in particular in an evacuated interior. [5] Arrangement (1) according to any one of the preceding claims, characterized by , that at least one movable contact piece (4) is made of copper or comprises copper, and / or that the rod (8) is made of copper, steel, plastic or glass fiber reinforced plastic, and / or that the rod (7) is made of copper, aluminum, plastic or glass fiber reinforced plastic. [6] Arrangement (1) according to any one of claims 1 to 4, characterized by , that at least one movable contact piece (4) is made of copper, and that the rod (8) is made of aluminum, and that the rod (7) is made of copper or steel. [7] Arrangement (1) according to any one of the preceding claims, characterized by, that the rod (7) is screwed into the at least one movable contact piece (4) at one end, and / or that the rod (8) is attached to the rod (7) at one end via a nut (9). [8] Arrangement (1) according to any one of the preceding claims, characterized by that the rod (8) is designed in the form of a sleeve and in particular spatially encompasses a part of the rod (7) in a form-fitting manner, especially in the area of ​​the bellows (6). [9] Arrangement (1) according to any one of the preceding claims, characterized by , that the length of the rod (8) essentially corresponds to the length of the bellows (6) when the vacuum switching tube (2) is switched on. [10] Arrangement (1) according to any of the preceding claims, characterized by, that the vacuum switching tube (2) comprises at least one fixed contact piece (3), in particular arranged along a common longitudinal axis opposite the at least one movable contact piece (4), and / or arranged at least partially in the housing (5). [11] Arrangement (1) according to any of the preceding claims, characterized by , that the housing (5) of the vacuum switching tube (2) comprises at least one ceramic hollow cylinder (10), in particular fluid-tightly sealed at the ends by metal caps (11), contact pieces (3 and 4), and the at least one bellows (6). [12] Arrangement (1) according to any of the preceding claims, characterized by , that the vacuum switching tube (2) is designed to switch voltages in the high-voltage range, in particular in the range greater than or equal to 52 kV. [13] Method for manufacturing an arrangement (1) according to one of the preceding claims, wherein the vacuum switching tube (2), in particular comprising the movable contact piece (4) and the at least one bellows (6), is sealed fluid-tight by soldering, and in a subsequent step the rod (7) and the rod (8), in particular via a nut (9), are connected to the movable contact piece (4), in particular by screwing.

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