DE102020210912A1 - A gas-insulated medium or high-voltage switchgear with a blade contact carrier - Google Patents

Abstract

The invention relates to a gas-insulated medium or high-voltage switchgear (1) with a switching unit which is arranged in a gas-insulated room (2) and comprises a circuit breaker and a disconnector arranged above the circuit breaker. The circuit breaker has a plurality of vacuum interrupters (4) arranged along a depth direction (3) and aligned vertically. The circuit breaker has a force transmitter (5) arranged along the depth direction (3) and a number of pivotable knife contacts (7) arranged on a knife contact carrier (6) corresponding to the plurality of vacuum interrupters (4). The force transmitter (5) is designed to move the blade contacts (7) between an operating position, in which each of the blade contacts (7) makes contact with a respective operating contact (8), and a grounding position, in which each of the blade contacts has a respective grounding contact (9). contacted, to pivot over a separating position located between the operating position and the grounding position, in which the blade contacts (7) are electrically separated. According to the invention, the blade contact carrier (6) is made of plastic.

Description

technical field

The invention relates to a gas-insulated medium or high-voltage switchgear (hereinafter also simply referred to as “switchgear”).

Technical background

Gas-insulated switchgear is used in the medium-voltage (1-kilovolt to 52-kilovolt) and high-voltage (over 52-kilovolt) ranges to enable high power densities in a small installation space. Basically, there is a desire to be able to switch the greatest possible power with a switchgear, which is why the voltages and currents to be switched are increased within the scope of the technical possibility. Sulfur hexafluoride (SF6) or, because of its high greenhouse gas effect, a substitute gas with similar properties is used as the insulating gas.

Standardized sizes of gas-insulated switchgear have become established, so that new switchgear for higher voltages and currents must have the same size as conventional switchgear, since existing rooms for operating switchgear are usually set up for this standardized size. This means increasing challenges in the development of the switchgear, since the necessary insulating distances increase with the voltages and the forces acting in the switchgear with the currents due to the magnetic field of the currents.

The object of the invention is therefore to introduce an improved gas-insulated medium or high-voltage switchgear which enables high voltages and currents to be switched.

The invention solves this problem by means of a gas-insulated medium or high-voltage switchgear according to claim 1. Preferred embodiments of the invention form the subject matter of the dependent claims.

Summary of the Invention

The invention relates to a gas-insulated medium or high-voltage switchgear with a switching unit arranged in a gas-insulated room, which comprises a circuit breaker and a circuit breaker arranged above the circuit breaker. The circuit breaker has a plurality of vacuum interrupters arranged along a depth direction and aligned vertically. The circuit breaker has a force transmitter arranged along the depth direction and a number of pivotable knife contacts arranged on a knife contact carrier that corresponds to the plurality of vacuum interrupters. The force transmitter is designed to switch the blade contacts between an operating position, in which each of the blade contacts makes contact with a respective operating contact, and a grounding position, in which each of the blade contacts makes contact with a respective grounding contact, via a disconnected position located between the operating position and the grounding position, in which the knife contacts are electrically separated. According to the invention, the blade contact carrier consists of plastic.

Plastic has the advantage that on the one hand it is light and stable, on the other hand it is a good insulator, which is why it does not affect the electrical fields occurring in the switchgear or only very slightly, so that the field distribution in the switchgear is reliable and with a blade contact carrier that can change position with the blade contacts can be determined independently of its position so that flashovers can be reliably prevented.

Insofar as directional information such as “depth direction”, “above”, “below” etc. is used here, this directional information relates to an operational gas-insulated medium or high-voltage switchgear according to the invention, seen from the position of a person standing in front of the switchgear.

The blade contact carrier preferably has a plurality of webs which are arranged at least approximately perpendicularly to a main plane of extension of the blade contact carrier. The bars greatly increase the stability of the blade contact carrier while using less material.

The webs are particularly preferably arranged in the form of a grid. Such a grid-like arrangement of the webs advantageously increases the torsional rigidity.

In particular, the blade contact carrier can have a first edge running along a first direction and a second edge running along a second direction intersecting the first direction. At least a subset of the webs can be aligned transversely to the first and the second direction. As a result, forces occurring in the blade contact carrier are distributed particularly well in the blade contact carrier.

The force transmitter is particularly preferably a shaft which can be rotated about an axis of rotation, with the blade contacts being able to be pivoted about the axis of rotation.

The circuit breaker can also include a stationary, fixed contact carrier made of plastic, on which the operating contacts are arranged. The stationary fixed contact carrier can be constructed in the same way as described above for the blade contact carrier. The fixed contact carrier can hold the operating contacts so that the blade contacts can contact them. The fixed contact carrier can serve as a stop for the blade contact carrier when the circuit breaker is closed.

The gas-insulated medium- or high-voltage switchgear can have a plurality of field-shaping electrodes, which are arranged on the vacuum interrupters and are designed to shape an electric field that occurs during operation of the medium- or high-voltage switchgear. The field-shaping electrodes prevent field peaks that can lead to flashovers.

The gas-insulated medium or high-voltage switchgear can be equipped with a grounding switch which is arranged below the circuit breaker and is designed to electrically connect the lower contacts of the vacuum interrupters to a ground potential. In this case, the medium- or high-voltage switchgear is designed to close the power switch and the grounding switch in a grounding operating state and thereby to connect the grounding contacts of the isolating switch to the ground potential via the power switch and the grounding switch. In this configuration, the necessary grounded switching state of the switchgear is established by opening the circuit breaker to interrupt the flow of current after opening the circuit breaker, thereby creating a sufficiently large isolating distance to avoid spontaneous flashovers. For safety reasons, after disconnection, the parts of the switchgear that are live until the circuit breaker is opened are grounded in a further step that is customary in the trade. For this purpose, a separate grounding switch is normally provided, which, however, is arranged in the switchgear according to the invention for reasons of space on the physically and electrically opposite side of the circuit breaker from the point of view of the isolating switch. So that the desired grounding is achieved, the circuit breaker is therefore closed again in order to connect the grounding contacts of the isolating switch to the ground potential contacted via the grounding switch via the circuit breaker. The switchgear according to the invention has a particularly space-saving design.

The gas-insulated medium- or high-voltage switchgear can have a plurality of bushings arranged above the switching unit into a busbar space of the medium- or high-voltage switchgear, with the operating contacts of the disconnector being screwed directly to the bushings. This means that there is no conductor screwed to the operating contact at one end and to the bushings at the other end. This would result in an additional resistive screw connection, which would result in increased heat generation.

The gas-insulated medium- or high-voltage switchgear can have a plurality of bushings arranged transversely to the depth direction into a cable connection space, each bushing being connected to an associated connection of the switching unit via a respective conductor. The arrangement of the vacuum interrupters along the depth direction enables greater insulation distances between the individual vacuum interrupters, because switchgear is usually deeper than it is wide. However, the cable connection room is usually behind the gas-insulated room, which is why this common spatial arrangement is made possible by the conductors in a connection-compatible manner to a switchgear previously located at the same place.

character list

• 1 eine erste perspektivische Seitenansicht des Ausführungsbeispiels der Erfindung;
• 2 eine zweite perspektivische Seitenansicht des Ausführungsbeispiels der Erfindung; und
• 3 eine perspektivische Seitenansicht eines Trennschalters des Ausführungsbeispiels der Erfindung.

The invention is explained in more detail below with reference to illustrations of an exemplary embodiment. Show it:

• 1 a first perspective side view of the embodiment of the invention;
• 2 a second perspective side view of the embodiment of the invention; and
• 3 12 is a side perspective view of a circuit breaker of the embodiment of the invention.

Detailed picture description

the 1 and 2 show perspective side views of an embodiment of the invention, wherein the 1 and 2 show the switchgear 1 according to the invention from opposite directions. 3 shows a perspective side view of a circuit breaker of the embodiment of the invention and thus also in the 1 and 2 shown functional unit in enlargement. All three figures are described together below.

the and show for reasons of simplification only a section of a gas-insulated medium or high-voltage system 1, the Essentially comprises the gas-insulated space 2 filled with an insulating gas during operation and a drive unit. A depth direction 3 is shown in the figures, which corresponds to the direction in which a person standing in front of an operating panel 16 of the switchgear assembly 1 is looking at the switchgear assembly 1 . Central components of the circuit breaker of the switchgear are the vacuum interrupters 4, three of which, ie one for each phase of a three-phase network, are arranged one behind the other in the depth direction 3. By arranging the vacuum interrupters 4 in the depth direction 3, the insulating distances required for higher voltages can be maintained, for which the width of the switchgear 1, the so-called field width, is not sufficient. The vertical orientation of the vacuum interrupters 4 has the advantage that heat can be transported away from the vacuum interrupters 4 by convection of the insulating gas in order to be released to the environment via a wall of the gas-insulated space 2 .

Moving contacts of the vacuum interrupters 4 can be moved by a spring drive and a current flow through the vacuum interrupters 4 can be interrupted or made possible. An electric drive 18 which is arranged outside of the gas-insulated space 2 and which can have an electric motor and a gear, for example, is provided for tensioning the springs.

The vacuum tubes 4 are connected to an isolating switch arranged above the circuit breaker, with field-shaping electrodes 12 being provided at the poles of the vacuum tubes to shape the electric field. The field-shaping electrodes 12 prevent the occurrence of local field peaks that could lead to flashovers. The circuit breaker essentially consists of a drive 17 which is connected to a blade contact carrier 6 which carries blade contacts 7 via a force transmitter 5 - in the example shown a shaft which can be rotated about an axis of rotation. The blade contact carrier 6 can be pivoted between an operating position and a grounding position, with a disconnection position being provided between the operating position and the grounding position, in which the blade contacts 7 are electrically disconnected.

In the operating position, the blade contacts 7 make contact with fixed operating contacts 8, which are screwed directly to bushings 13 in a busbar space in the switchgear (not shown). The direct screw connection eliminates the need for another screw connection that is subject to resistance, so that less heat is generated during operation due to the resistance losses.

In the grounding position, the blade contacts 7 make contact with grounding contacts 9, which are electrically connected to one another. The grounding contacts 9 can be connected directly to ground potential. Alternatively, they can be connected to ground potential indirectly via the vacuum interrupters 4 by activating a grounding switch arranged below the vacuum interrupters 4 and closing the vacuum interrupters 4 .

According to the invention, the blade contact carrier 6 is made of plastic. In the example shown, it has a multiplicity of webs 10 which are perpendicular to a main plane of extension of the blade contact carrier 6 and give it increased stability. The webs 10 run at an angle to one another, at least in some areas of the blade contact carrier 6, so that they form a lattice. A density and/or thickness of webs can be greater at points on blade contact carrier 6 that are exposed to particularly high mechanical loads during operation than at other points. When the disconnector is moved into the operating position, the blade contact carrier 6 pivots against a fixed contact carrier 11 so that the latter forms a stop for the blade contact carrier 6 . The fixed contact carrier 11 is preferably also constructed from plastic provided with webs.

Furthermore, bushings 14 into a cable connection space of the switchgear (not shown) are provided below the vacuum interrupters 4 . Like the bushings 13, these bushings are designed to be gas-tight in order to seal off the gas-insulated space 2 from the environment. The corresponding poles of the vacuum interrupters 4 are connected to the bushings 14 via conductors 15, which are preferably designed as solid or hollow copper rods.

The invention has been described in more detail using an exemplary embodiment. The exemplary embodiment is intended to serve merely as an illustration and not to limit the invention, which is defined solely by the following claims.

Reference List

1

gas-insulated medium or high voltage switchgear

2

gas insulated room

3

depth direction

4

vacuum interrupter

5

power transmitter

6

blade contact carrier

7

blade contact

8th

operating contact

9

ground contact

10

webs

11

fixed contact carrier

12

field shaping electrode

13

Bushings in busbar room

14

Penetrations in cable connection room

15

ladder

16

control panel

17

Drive earthing switch

18

drive circuit breaker

Claims (10)

A gas-insulated medium- or high-voltage switchgear (1) with a switching unit arranged in a gas-insulated room (2), which has a circuit breaker, which has a plurality of vacuum interrupters (4) arranged along a depth direction (3) and aligned vertically, and one arranged above the circuit breaker Disconnector which has a force transmitter (5) arranged along the depth direction (3) and a number of pivotable blade contacts (7) arranged on a blade contact carrier (6) corresponding to the plurality of vacuum interrupters (4), the force transmitter (5) being designed for this purpose the blade contacts (7) between an operating position in which each of the blade contacts (7) contacts a respective operating contact (8) and a grounding position in which each of the blade contacts (7) contacts a respective grounding contact (9) via an intermediate the operating position and the grounding position located disconnection position in which the blade contacts (7) are electrically disconnected, characterized in that the blade contact carrier (6) consists of plastic. The gas-insulated medium or high-voltage switchgear (1) of the preceding claim, in which the blade contact carrier (6) has a plurality of webs (10) which are arranged at least approximately perpendicular to a main plane of extension of the blade contact carrier (6). The gas-insulated medium or high-voltage switchgear (1) of the preceding claim, in which the webs (10) are arranged in the form of a grid. The gas-insulated medium- or high-voltage switchgear (1) of one of the two preceding claims, in which the blade contact carrier (6) has a first edge running along a first direction and a second edge running along a second direction intersecting the first direction, with at least a subset of the Webs (10) is aligned transversely to the first and the second direction. The gas-insulated medium or high voltage switchgear (1) of one of the preceding claims, in which the force transmitter (5) is a shaft which can be rotated about an axis of rotation and in which the blade contacts (7) can be pivoted about the axis of rotation. The gas-insulated medium or high voltage switchgear (1) of the preceding claim, in which the circuit breaker further comprises a fixed plastic contact carrier (11) on which the operating contacts (8) are arranged. The gas-insulated medium- or high-voltage switchgear (1) of one of the preceding claims, with a plurality of field-shaping electrodes (12), which are arranged on the vacuum interrupters (4) and are designed to generate an electric field that occurs during operation of the medium- or high-voltage switchgear (1). to shape. The gas-insulated medium- or high-voltage switchgear (1) of one of the preceding claims, with a grounding switch arranged below the circuit breaker, which is designed to connect lower contacts of the vacuum interrupters (4) electrically to a ground potential, the medium- or high-voltage switchgear being designed to to close the circuit breaker and the earthing switch in an earthing operating state and thereby to connect the earthing contacts (9) of the disconnector to the earth potential via the circuit breaker and the earthing switch. The gas-insulated medium- or high-voltage switchgear (1) of one of the preceding claims, with a plurality of bushings (13) arranged above the switching unit in a busbar space of the medium- or high-voltage switchgear (1), the operating contacts (8) of the disconnector being connected directly to the bushings (13) are screwed. The gas-insulated medium- or high-voltage switchgear (1) of one of the preceding claims, with a plurality of bushings (14) arranged transversely to the depth direction (3) into a cable connection compartment, each bushing (14) having a respective conductor (15) with an associated Connection of the switching unit is connected.

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