EP3807920A1 - Vacuum interrupter and high-voltage switching assembly - Google Patents

Abstract

The invention relates to a vacuum interrupter (2), comprising: a housing (3) having at least one annular ceramic insulating element (4), which forms a vacuum chamber (6), a contact system (8) having two contacts (9, 10), which are movable relative to one another. The invention is characterized in that a capacitive element (12) having two electrodes (14) and having a dielectric material (16) arranged between the electrodes (14) is provided, the capacitive element (12) being interlockingly mounted on the insulating element (4) and having a capacitance between 400 pF and 4000 pF.

Description

description

Vacuum switching tube and high-voltage switching arrangement

The invention relates to a vacuum interrupter according to the preamble of claim 1 and a high-voltage switching arrangement according to claim 14.

In high-voltage or extra-high voltage transmission networks, the gas or vacuum circuit breaker is used to interrupt operating and fault currents. To meet the voltage requirements, especially in transmission systems that have a nominal voltage of more than 380 kV, power switching chambers are connected in series in order to comply with the performance data prescribed by the standard. In order to avoid overloading an individual power switching chamber in this series connection, it is necessary to control the voltage distribution. As a rule, the voltages are distributed over the individual parts of the power interrupters to 50% each. For this purpose, control elements are connected in parallel with the individual power switching chambers in accordance with the state of the art. Such a control element is usually a capacitor or a capacitor and a resistor connected in series. Controls of this type require additional installation space and are to be attached in an insulated manner, which leads overall to a high technical and thus cost-intensive effort.

The object of the invention is to provide a vacuum interrupter for high-voltage applications and a high-voltage switching arrangement which, compared to the prior art, has a lower technical outlay for providing control elements.

The object is achieved in a vacuum interrupter with the features of claim 1 and in a high-voltage switching arrangement with the features of claim 14. The vacuum interrupter according to the invention comprises a housing with at least one annular ceramic isolator element, which forms a vacuum space. Furthermore, the vacuum interrupter comprises a contact system with two contacts arranged to be movable relative to one another. The vacuum interrupter is characterized in that a capacitive element with two electrodes and a dielectric material arranged between the electrodes is provided, the capacitive element being positively attached to the insulator element and having a capacitance that is between 400 pF and 4000 pF having.

The vacuum interrupter according to the invention has the advantage over the prior art that the control element required for distributing the voltage to the individual power switching chambers is integrated into the vacuum interrupter, specifically on the surface of the insulator element. This leads to a saving in manufacturing costs and to a lower technical outlay when providing the vacuum interrupter and to avoid assembly costs.

In one embodiment of the invention, in addition to the capacitive element, that is to say the capacitor, there is also a resistive element, that is to say a resistor and likewise integrated in at least one insulator element. This can be used in particular for a series connection of resistive element and capacitive element and for a series connection of these two elements.

In particular, the dielectric material of the capacitive element is applied in layers on a surface of the isolator element. Basically, both the inner and the outer surface of the Isolatorelemen are suitable for this, but the attachment of the resistive element on the outer surface has the advantage that a higher selection of materials, such as a ferroelectric material, embedded in an epoxy resin matrix, are available . as there are very special requirements for the outgassing behavior of the materials for the inner surface.

The resistance of the resistive element preferably has a value which is between 100 ohms and 1500 ohms or between 10 ⁸ and 10 ¹⁵ ohms.

The dielectric material is preferably applied as a layer on the surface of the insulator element and the layer has a thickness of 5 μm to 150 μm or 1 mm to 5 mm. The associated electrodes are arranged with respect to an extension of the insulator element along a switching axis on an upper and a lower end face. It is expedient if the electrodes are integrated in solder points between insulator elements. Electrodes can be easily attached to these end faces and between them the dielectric material can be attached to the outer surface of the insulator element and thus contacted. The integration of the electrodes in the solder points is useful but not necessary. The soldering point itself can also serve as an electrode.

As an alternative or in addition, it is also expedient that the electrodes are arranged in the form of a layer or a wrapping on the outer surface of the insulator element, so that the dielectric material is in turn arranged on this in a second layer or second winding and that one in a alternating layer sequence of electrodes and dielectric material on the outer surface of the insulator material, the capacitive element is generated.

In principle, a material with a high dielectric constant, in particular a ferroelectric material, is suitable as the dielectric material, in particular a titanate is suitable, particularly preferably the barium titanate. A further embodiment of the invention is a high-voltage switching arrangement which comprises a vacuum interrupter according to one of the preceding claims and which also has a further interrupter unit connected in series with it. This is a high-voltage switching arrangement which is basically known from the prior art, but comprises at least one vacuum interrupter according to the invention as a series-connected interrupter unit, so that the corresponding control elements, in particular capacitive capacitors, can be dispensed with in the described high-voltage switching arrangement , One of the two interrupter units is preferably the described vacuum interrupter and a second interrupter unit is a gas-insulated switch. If a gas-insulated switch is used, a parallel connection of conventional control elements to the gas-insulated switch is required.

Further embodiments and further features of the inven tion result from the following description of the figures. Features with the same name but in different configurations are provided with the same reference numerals. These are purely schematic configurations that have an exemplary character and do not represent a restriction of the scope of protection. Show:

FIG. 1 shows an equivalent circuit diagram of a high-voltage switching arrangement from the prior art with control elements connected in parallel,

FIG. 2 shows a high-voltage switchgear assembly with two interrupter units connected in series and having integrated control elements,

FIG. 3 shows a cross section through a vacuum interrupter with resistive and capacitive control elements integrated on the surfaces of insulator elements, FIG. 4 shows an equivalent circuit diagram of the arrangement of the capacitive and resistive elements for the vacuum interrupter according to FIG. 3,

5 shows a cross section through a vacuum interrupter according to FIG. 1 with control elements in the lower and upper region of the vacuum interrupter,

FIG. 6 shows an equivalent circuit diagram of the control elements for the vacuum interrupter according to FIG. 5,

FIG. 7 shows a vacuum interrupter according to FIG. 1 with control elements according to the equivalent circuit diagram from FIG. 8,

8 shows an equivalent circuit diagram of the control elements for the vacuum interrupter according to FIG. 7,

FIG. 9 shows a vacuum interrupter according to FIG. 1, the capacitive element being applied to an insulator element in the form of an alternating layer,

FIG. 10 shows an enlarged section of the layer sequence from section X in FIGS. 9 and

FIG. 11 shows an equivalent circuit diagram for the control element according to the vacuum interrupter from FIG. 9.

In Figure 1, a series connection of two interrupter units 32 is shown according to the prior art. These breaker units 32 can be gas-insulated switches, but it can also be vacuum interrupters. In parallel to the interrupter units 32 connected in series, control elements 34 are connected in order to protect the individual interrupter units 32 in this series circuit from overload. For this purpose, resistors or capacitors are used in parallel or in series. The tensions conditions are thereby divided between the individual interrupter units 32 and an overload is prevented.

FIG. 2 shows an embodiment in which an interrupter unit 32 in the form of a vacuum interrupter 2 is connected in series with a further interrupter unit 32. The vacuum interrupter 2 has control elements 34 which are designed in the form of capacitive elements 12 and which are integrated in the vacuum interrupter 2, as will be explained in more detail in accordance with FIG. 3.

Figure 3 shows a cross section through a vacuum interrupter 2, which has a housing 3, the housing 3 having a plurality of insulator elements 4 and a centrally attached metal screen 5. The metal screen 5 is arranged in the housing 3 so that it is mounted in the position in which contacts 9 and 10, which together form a contact system 8, are movably mounted along a switching axis 24.

The insulator elements 4 are designed essentially cylindrical, whereby they are also stacked one above the other along the switching axis 24 and form a cylinder along this switching axis 24, which also form the cylinder axis. The individual insulator elements 4 are positively connected to one another, a solder connection predominating in most cases. The housing 3, which encloses the contact system 8, thereby forms a vacuum space 8, which is closed in a vacuum-tight manner with respect to the atmosphere.

To the extent that it is seen schematically, it is a conventional vacuum interrupter 2 according to the prior art. The present vacuum interrupter 2 differs from this in that control elements 34 are arranged on surfaces 20, 21 of the isolator elements 4, at least one capacitive element 12 being applied to a surface 20, 21 of the isolator element 4. There is no need to explicitly differentiate between an inner 21 and outer surface 20 of the isolator element, although in many cases it is useful it is moderate to apply the capacitive element 12 to the outer surface 20 of the insulator element 4.

Electrodes 14 are provided, which are preferably arranged between end faces 25 and 26 of the insulator elements 4 along the switching axis 24. The electrodes 14 can be extensions of solder surfaces 27, which are used to connect the individual insulator elements 4. The electrodes 14 protrude radially to the axis 24 seen a little way over the end faces 25 and 26 of the insulator elements 4, so that between these protruding projections of the electrical 14, a dielectric material 16 is arranged on the outer upper surface 20 of the insulator element 4 which is contacted by the electrodes 14. The electrodes 14, which contact the dielectric material 16, together form the capacitive element 12.

Furthermore, it is expedient that a resistive material 19 is likewise arranged between electrodes 14, which are fundamentally identical, and is contacted by them. This results in the resistive element 18 together with the electrodes. In the illustration according to FIG. 3, a capacitive element is arranged on the uppermost insulator element 4 on the outer surface 20, which is connected via the same electrodes 14 as the resistive element on the inside of the isolator element 4. This results in a parallel connection of the two control elements 34. Together with a further resistive element 18 on the adjacent isolator element 4 in FIG. 3, the equivalent circuit diagram according to FIG. 4 results.

As a material for the capacitive element 12, that is, the dielectric material 16, a material with a high s _r, ie, a high dielectric constant, is preferably used to set the desired capacitance. Ferroelectric materials are particularly suitable for this purpose, a titanate; barium titanate (s _r = 1000) is preferably used. In order to achieve an appropriate capacitance from 400 pF to 4000 pF, the dielectric material can contain the barium titanate Obtain concentrations that lead to the desired capacitance at a given layer thickness of the dielectric material 16 on the insulator element 4. A dielectric material in which the barium titanate is embedded in an epoxy resin matrix is particularly advantageous. The thickness of the layer of the dielectric material 16 of the capacitive element 12 is generally more between 5 μm and 150 μm or between 1 mm and 5 mm.

5 shows a representation of the vacuum interrupter 2 according to FIG. 1, the arrangement of the control elements 32 being distributed symmetrically between the housing 3 and the isolator elements 4 with respect to the housing 3. This enables a targeted voltage distribution along the housing 3 to different insulator elements 4. This is a series connection between a capacitive element 12 and a resistive element 18, as is shown as an equivalent circuit diagram in FIG. 6.

FIG. 7 also shows a vacuum interrupter 2 according to FIG. 1, both a capacitive element 12 and a resistive element 18 being attached to the outer surface 20 of the isolator element 4. Here, the dielectric material 16 is seen radially inside, followed by insulation not described here and then the resistive material 19. Both the dielectric material 16 and the resistive material 19 are with the electrodes 14 according to the equivalent circuit diagram from FIG 8 connected to a parallel connection. A further resistive element 18, as already described, is applied to the subsequent insulator element 4, so that a further resistive element 18 is connected in series with the parallel connection of the resistive element 18 and the capacitive element 12, as shown in FIG. 8 is shown as an equivalent circuit diagram. This circuit can also be repeated symmetrically on the lower part of the housing 3, analogously to FIG. 5. Basically, the representation and the arrangement of the resistive or capacitive tive elements 12, 18 to exemplary embodiments. They could also be arranged on all other insulator elements 4. Here, and this applies equally to FIGS. 3, 5, 7 and 9, all control elements 34 can be attached both to an inner surface 21 and to an outer upper surface 20 of the insulator elements 4.

An alternative embodiment of the capacitive element 12 is shown in FIG. Here, alternating layers of electrode 14 and dielectric material 16 ra dial are wrapped around the outer surface 20 of the insulator element 4. An enlarged representation of the detail X in FIG. 9 is shown in FIG. Here is the layer fol ge on the outer surface 20 with electrode 14, and the dielectric material 16 can be seen. Thus, a dielectric material 16 is embedded in each case by a layer of conductive electrode material in the form of the electrode 14. In this way, the corresponding desired capacities of the control element 34 can be set more precisely by the number of individual layers. The corresponding replacement circuit diagram is given in Figure 11. Here is only an example of a capacitance or a capacitive element 12 represents Darge. The vacuum interrupter shown in FIG. 9 can also be provided with further control elements, as described in FIGS. 3, 5 and 7, in any combination, both inside and outside, as required.

Reference character list

2 vacuum interrupters

 3 housing

 4 isolator element

 5 metal screen

 6 vacuum room

 8 contact system

 9 moving contact

 10 fixed contact

 12 capacitive element

 14 electrodes

 16 dielectric material

 18 resistive element

 19 resistive material

 20 outer surface insulator element

 21 inner surface

 22 layer dielectric material

 24 switching axis

 25 upper face

 26 lower end face

 27 solder surfaces

 28 switching arrangement

 32 breaker unit

 34 control

 36 Series connection of power interrupters

Claims

claims 1. Vacuum interrupter (2) comprising  - A housing (3) with at least one annular ceramic insulating element (4) forming a vacuum chamber (6),  - A contact system (8) with two mutually movably arranged contacts (9, 10), characterized in that a capacitive element (12) with two electrodes (14) and egg nem arranged between the electrodes (14) dielectric material (16) is provided, the capacitive element (12) being positively attached to the insulator element (4) and having a capacitance between 400 pF and 4000 pF. 2. Vacuum interrupter according to claim 1, characterized in that in addition to the capacitive element (12), a resistive element (18) is provided on at least one insulator element (4). 3. Vacuum interrupter according to claim 1 or 2, characterized in that at least the dielectric material (16) of the capacitive element (12) is applied in layers to a surface (20) of the insulator element (4). 4. Vacuum interrupter according to one of the preceding claims, characterized in that the capacitive element (12) is arranged on an outer surface (20, 21 of the insulator element (4). 5. Vacuum interrupter according to one of claims 2 to 4, characterized in that the capacitive element (12) and the resistive element (18) are connected in series. 6. Vacuum interrupter according to one of claims 2 to 5, characterized in that the resistive element (18) is positively connected to the insulator element (4). 7. Vacuum interrupter according to one of claims 2 to 6, characterized in that the resistive element has a Wi resistance, which is between 100 ohms and 1500 ohms or between 10 ⁸ ohms and 10 ¹⁵ ohms. 8. Vacuum interrupter according to one of the preceding claims, characterized in that the dielectric material (16) as a layer (22) on the surface (20, 21) of the Isolatorele element (4) is applied and the layer (22) has a thickness of 5 ym to 150 ym or 1 mm to 5 mm. 9. Vacuum interrupter according to one of the preceding claims, characterized in that the electrodes (14) are arranged on the insulator element (4) so that they relate to an extension of the insulator element along a switching axis (24) on an upper and on an lower end face. 10. Vacuum interrupter according to claim 9, characterized in that the electrodes (14) are integrated in solder points between the isolato elements. 11. Vacuum interrupter according to one of the preceding claims, characterized in that the electrode (14) is applied as a layer on the outer surface (20, 21) of the isolator element (4). 12. Vacuum interrupter according to claim 11, characterized in that the capacitive element (12) as an alternating Layer sequence of electrode (14), dielectric material (16) and electrode (14) on the outer surface (20, 2) of the insulator element (4) is arranged. 13. Vacuum interrupter according to one of the preceding claims, characterized in that the dielectric material (16) contains a ferroelectric material, in particular a titanate, particularly preferably barium titanate. 14. High-voltage switching arrangement (28) comprising a vacuum interrupter (2) according to one of claims 1 to 13 and a further interrupter unit (32) connected in series. 15. High-voltage switching arrangement according to claim 14, characterized in that the interrupter unit (32) is a vacuum switching tube (2) or a gas-insulated switch.