EP3928339B1 - High-voltage circuit breaker system - Google Patents

Description

The invention relates to a high-voltage circuit-breaker system according to the preamble of patent claim 1.

So-called short circuit breakers are defined for fault clearance in high and extra-high voltage networks, i.e. at voltages over 110 kilovolts in overhead lines. If a short-circuit is caused, for example, by a falling tree, a falling branch or a large bird, the switch interrupts the short-circuit current within a very short time. The circuit breaker switches off in a time of approx. 300 milliseconds and thus separates the area in which the short circuit occurs from the rest of the network. Since short circuits of this type often regenerate themselves, for example because the element causing the short circuit has burned off, the circuit breaker is closed again after a defined time, which is generally less than one second. If it is determined that the short circuit no longer occurs, the circuit breaker remains closed. If the short-circuit persists, the switch must be opened again very quickly, i.e. also within approx. 300 milliseconds, in order to prevent further damage to the network. This opening then remains stationary for the time being until the cause has been remedied manually. Such functionality, which usually corresponds to the specifications of the network operator, is called open-close-open functionality, abbreviated O-C-O.

For this OCO functionality, conventional circuit breakers in the high-voltage grid have stored-energy spring mechanisms, which can be used to switch them on and off again. During the switching operation, one spring accumulator is triggered and the other spring accumulator is tensioned. This release-tensioning process is reversed for the next switching operation. While this design is well established, its implementation However, each requires a relatively high mechanical effort. In addition, the triggering mechanism for each opening or closing action is technically complex. From the EP 2 421 017 A1 a switchgear for medium voltages is known, with a crankshaft which switches three poles synchronously. The document EP2421017 discloses a high voltage circuit breaker system according to the preamble of claim 1.

The object of the invention is to provide a circuit breaker system for a high-voltage application which has the open-close-open functionality and, compared to the prior art, has a technically less complex and compact drive system for a number of circuit breakers.

The solution to the problem consists in a high-voltage circuit breaker system with the features of patent claim 1.

The high-voltage circuit breaker system according to the invention with an auto-reclosing function, which results in an opening, closing and reopening movement of a contact system, comprises precisely this contact system which is mechanically connected to a drive system. The drive system has a drive assembly. In addition to the drive unit, the drive system also includes a drive shaft, which is designed in the form of a crankshaft. This crankshaft is connected to a moving contact of the contact system via a connecting rod. Furthermore, the invention is characterized in that the cycle of the opening, closing and renewed opening movement of the contact system takes place through a unidirectional rotary movement of the crankshaft.

In contrast to the spring-loaded drives conventionally used, the advantage of the invention is that a drive unit performs the required opening, closing and further opening process via the crankshaft in a unidirectional rotary movement during one revolution of a shaft can. This construction makes it possible to use simple drive units, such as electric motors or spiral springs. This significantly reduces the technical effort involved in constructing the drive unit. Due to the reduced technical complexity, the corresponding drive units can also be made more cost-effective.

A crankshaft is a shaft with one or more cranks that describe an eccentric rotary movement with respect to the axis of rotation of the shaft. A push rod or connecting rod may be attached to the cranks, thereby converting rotational movement of the crankshaft into translational movement. A crank can be a conventional elongated lever, but a crank can also be designed in the form of an extender disk.

An auto-reclosing function of a circuit breaker is, in the event of a short circuit, to open the power line for a short time, on the order of less than half a second, to short it out again for a similar period of time, after which it is possible to check whether a short circuit is still present, and to open it again , if there is still a short circuit. Should the short circuit clear during the first interrupt interval, the circuit breaker will remain in the closed position.

The term “mechanically connected” means that there is a mechanical connection for the transmission of a force, an impulse or an action between two systems, for example via movable connections such as bearings or joints, but also via fixed connections such as material or non-positive connections or from combinations of movable and fixed connections.

In one embodiment of the invention, the crankshaft is designed in such a way that, starting from a closed position of the contact system to an open position of the contact system, a unidirectional rotary movement is performed, which is between 150° and 210° with respect to its axis of rotation. Basically, when using a crankshaft, a rotary movement of 180° between the closed position and the open position is advantageous. Due to geometrical requirements and taking into account opening and closing times, the optimum rotational movement for the opening process can be in a range that deviates from 180°, that is between 150° and 210°.

In a further embodiment of the invention, the crankshaft is designed in such a way that for the cycle of opening, closing and renewed opening movement of the contact system, a unidirectional rotary movement is performed with respect to the axis of rotation of the crankshaft, which is between 350° and 360° plus 10°. Here, too, it is useful for the crankshaft to rotate by 360° for the entire cycle. In principle, however, an increased or reduced contact pressure between contacts of the contact system can, for example, be implemented by over-rotation or under-rotation, that is to say 10° less than 360° or 10° more than 360°.

The crankshaft is preferably designed in such a way that a crank pin which is eccentric with respect to the axis of rotation is arranged on a crank and describes a circular movement about the axis of rotation of the crankshaft during the rotary movement of the crankshaft. It is also useful that this crank pin is aligned parallel to the axis of rotation. Furthermore, the crank pin can be surrounded by a plain bearing of the connecting rod, thus ensuring the transmission of power and the conversion of the rotary movement into a translatory movement.

The crankshaft has at least three cranks, which has the advantage that a number of circuit breakers can be operated simultaneously by a drive shaft, ie by the crankshaft and by a drive. Depending on the design, the term three cranks means that at least three pins are present, each of which is surrounded by a pair of cranks and rotate at an eccentric distance from the axis of rotation of the crankshaft. The terms crank and pair of cranks have equivalent meanings, since when using more than one crank or pair of cranks and a rotational movement of almost or more than 360°, pairs of cranks are inevitably required in order not to block the rotational movement of the connecting rod.

These three cranks or pairs of cranks have different rotational directions with respect to the axis of rotation of the crankshaft. The first crank or the first pair of cranks preferably points in one direction, and the second pair of cranks points in a second direction, which is offset in the order of 180° to the first crank. The third crank again preferably points in the direction of the first crank. In this way, three circuit breakers can be operated by a common crankshaft and a common drive. It is also possible to move the circuit breakers closer to one another due to the offset design of the cranks, since they are arranged offset, which results in a roughly triangular arrangement of the circuit breakers. In this way, a great deal of installation space can be saved when accommodating the circuit breakers.

Further embodiments of the invention and further features are explained in more detail with reference to the following figures. These are purely exemplary, very schematic representations that are intended to explain the basic principle of the design in more detail. These are schematic representations that do not represent any limitation of the scope of protection.

Figur 1

ein Hochspannungs-Leistungsschaltersystem mit einem Kontaktsystem und einem Antriebssystem, wobei zur Übertragung der Antriebsenergie auf das Kontaktsystem eine Kurbelwelle Anwendung findet. Figur 1 zeigt das Kontaktsystem im geschlossenen Zustand,

Figur 2

Hochspannungs-Leistungsschaltersystem aus Figur 1 mit gedrehter Kurbelwelle und geöffnetem Zustand des Kontaktsystems,

Figur 3

das Hochspannungs-Leistungsschaltersystem gemäß Figur 1 wieder im geschlossenen Zustand nach einer Drehung der Kurbelwelle von ca. 180°,

Figur 4

das Hochspannungs-Leistungsschaltersystem in der gleichen Position wie in Figur 2 nach einer Drehung von 360° der Kurbelwelle,

Figur 5

eine Reihe von Hochspannungs-Leistungsschaltersystemen für drei Phasen, die durch ein Antriebssystem mit einem Antrieb und einer Kurbelwelle angetrieben werden,

Figur 6

ein Hochspannungs-Leistungsschaltersystem mit einer Kurbelwelle, die eine Exzenterscheibe als Kurbel aufweist,

Figur 7

eine Zeitachse zur Veranschaulichung des Öffnungs- und Schließzyklus,

Figur 8

einen Querschnitt durch eine Kurbelwelle entlang einer Kurbel und eine daran angebrachte Schubstange,

Figur 9

eine Draufsicht auf eine Anordnung von drei Hochspannungs-Leistungsschaltersystem, analog zu Figur 5 mit jedoch bezüglich der Drehachse rotatorisch versetzt angeordneten Kurbeln,

Figur 10

einen Hochspannungs-Leistungsschaltersystem mit einer Antriebsmechanik nach dem Stand der Technik.

show:

figure 1

a high-voltage circuit breaker system with a contact system and a drive system, a crankshaft being used to transmit the drive energy to the contact system. figure 1 shows the contact system in the closed state,

figure 2

High-voltage circuit breaker system from Figure 1 with rotated crankshaft and open state of the contact system,

figure 3

the high voltage circuit breaker system according to figure 1 again in the closed state after a rotation of the crankshaft of approx. 180°,

figure 4

the high voltage circuit breaker system in the same position as in figure 2 after a rotation of 360° of the crankshaft,

figure 5

a series of three phase high voltage circuit breaker systems driven by a drive system having an opener and a crankshaft,

figure 6

a high voltage circuit breaker system with a crankshaft having an eccentric disc as a crank,

figure 7

a timeline to illustrate the opening and closing cycle,

figure 8

a cross section through a crankshaft along a crank and a push rod attached to it,

figure 9

a plan view of an arrangement of three high-voltage circuit breaker system, analogous to figure 5 but with cranks that are rotationally offset with respect to the axis of rotation,

figure 10

disclose a high voltage circuit breaker system with a prior art operating mechanism.

In figure 1 1 is a schematic representation of a high voltage circuit breaker system having a contact system 4 arranged in a housing 42. FIG. The housing 42 is basically designed to be gas-tight; an insulating gas can be present inside the housing, which can be, for example, sulfur hexafluoride or a fluoroketone or a fluoronitrile. However, the insulating gas can also be synthetic, cleaned air. The circuit breaker 2 can also include a vacuum tube. The contact system 4 has a fixed contact 44 and a moving contact 14 . The moving contact 14 is connected to a contact bolt 40 which in turn is mechanically connected to a crankshaft 10 via a connecting rod 12 . The push rod 12 can be designed, for example, in the form of a conventional connecting rod. In this embodiment, the connecting rod 12 has a sliding bearing 38 or 40 at each of its ends, with the sliding bearing 38 being fastened to a pin 34 which is part of the crankshaft 10 . The journal 34 is framed by two cranks 32 which bring about the eccentric arrangement of the journal 34 from an axis of rotation 30 of the crankshaft 10 . The crankshaft 10 in turn is part of a drive system 6 which includes a drive unit 8 in addition to the crankshaft 10 . Various drive technologies can be used for the drive unit 8 . For example, an electric motor can ensure the drive, but spiral springs can also be used. The crankshaft 10 is supported in bearings 48 .

The drive unit 8 is designed in such a way that it moves in a direction of rotation 16 so that the crankshaft 10 also performs a unidirectional rotary movement along the arrow 16 . If this rotary movement 16 about the axis of rotation 30 of the crankshaft 10 takes place once by 360°, this leads to the results as shown in FIGS figures 2 , 3 and 4 is shown, first to an opening movement along the arrow 20 according to figure 2 , wherein for the maximum opening width of the contact system 4, ie the maximum movement of the moving contact 4, a 180° rotary movement of the crankshaft 10 along the direction of rotation 16 takes place. In this case according to figure 2 the contact system 4 is opened to the maximum and a further rotational movement of the crankshaft 10 takes place, preferably without interruption, in the same direction, with the contact system 4 closing again along the arrow 22; in this case, the crankshaft 10 has completed a rotational movement of 360°.

If it turns out that the cause of the short circuit still exists, a tripping unit (not shown here) gives the signal for a further 180° movement of the crankshaft 10, as per FIG figure 4 along the arrow 24 means a further opening movement. At this point according to figure 4 the cycle, which includes an opening, closing and reopening process, is completed. The high-voltage circuit breaker 2 initially remains open at this point.

In figure 7 this cycle is illustrated schematically along a time axis. At the time before and at time T ₀ there is no short circuit or any other confirmation of the network, so that the high-voltage circuit breaker 2 is closed in its basic position.

At time T ₀ there is a tripping event, which is caused by a trip unit, and the circuit breaker 2 is according to the figure 2 to an open position labeled O by time T ₁ . This period lasts approximately 300 milliseconds.

For a further period of time, which can be between 100 milliseconds and one second, the switch is switched back to normal figure 3 closed, this is present at time T ₂ . If the event causing the short circuit is still present, there is a further opening movement up to time T ₃ , according to FIG figure 4 .

In figure 5 a circuit breaker system 2 is shown in which three circuit breakers 3 are arranged next to one another and are jointly driven by a drive system 6 . The crankshaft 10 according to figure 5 has three cranks 32 which are each connected to a circuit breaker 3 .

The three circuit breakers 3 are switches for the individual phases of a power grid, which can be used to switch in the circuit breaker system 2 with a drive system 6 at the same time. The processes of the rotary movement along the arrow 16 correspond to what is described with reference to FIGS.

In figure 6 an analog circuit breaker system 2 is shown, which basically carries out the same movement sequences as is already the case with regard to the Figures 1 to 4 is described. However, the system 2 differs in the shape of the crankshaft 10, the crank 32 of the crankshaft 10 being designed in the form of an eccentric disk and being arranged at one end of the crankshaft 10. In this case, only one crank 32 and no pair of cranks is required, the crank pin 34 is arranged on the crank 32 in the form of an eccentric disc without a counter bearing in a second crank.

In figure 8 a cross section through a crankshaft 10 in the area of the crank pin 34 between two cranks 32 is shown. It is shown how the slide bearing 38, which in turn is connected to a push rod 12, is arranged around the crank pin 34. It is in figure 8 also evident how the crank pin 34 describes a rotational movement 36 eccentrically to the axis of rotation 30 and can complete a unidirectional rotation of initially 360° for opening and closing and then, if necessary, by a further 180°. The end of the push rod 12, which is provided with a further slide bearing (see FIG. 1, reference number 46), is in engagement with the contact pin 40, which is not shown in detail here.

In figure 10 Finally, an illustration of a drive mechanism of a high voltage circuit breaker system according to the prior art is given. The features that have the same designations as in the previous figures are provided with the same reference number followed by a prime. Such a circuit breaker system also has a contact system 4', which includes a fixed contact 44' and a moving contact 14', which in turn is operatively connected to a contact pin 40'. The contact system 4' is surrounded by a housing 42'. The difference from the previous description is that the cycle opening-closing and reopening, which is illustrated by the arrows 20', 22', is designed by a complex spring mechanism, with two spring accumulators 50-I and 50-II via a Rocker arms 52 are connected, which is shown here very schematically. The rocker arm 52 has the effect that when the contact system 4' is opened, a spring-loaded accumulator 50-I is relieved and, in return, the spring-loaded accumulator 50-II is tensioned. This process is reversed with a further opening or closing movement. This is an extremely complex mechanical arrangement that can be implemented alternatively by the technically simpler embodiment of the crankshaft 10 described.

Reference List

2

High Voltage Circuit Breaker System

3

circuit breaker

4

contact system

6

drive system

8th

drive unit

10

crankshaft

12

push rod

14

moving contact

16

unidirectional rotary motion

20

Open

22

Close

24

Reopen

26

closed position

28

opening position

30

axis of rotation

32

crank

34

mounting pin

36

circular rotation

38

bearings

40

contact studs

42

Housing

44

fixed contact

46

second plain bearing

48

crankshaft bearings

50

spring accumulator

52

rocker arm

Claims (6)

1. High-voltage circuit breaker system with a short-circuiting function that results in an opening movement (20), closing movement (22) and another opening movement (24) of a contact system (4), comprising a circuit breaker with a contact system (4) and a drive system (6) that is connected mechanically to the contact system (4), wherein the drive system (6) comprises a drive unit (8), and the drive system, in addition to the drive unit (8), has a driveshaft that is designed as a crankshaft (10) that is connected to a moving contact (14) of the contact system (4) via a push rod (12), and wherein the cycle of opening movement (20), closing movement (22) and another opening movement (24) of the contact system (4) results from a unidirectional rotational movement (16) of the crankshaft (10), wherein the crankshaft (10) has at least three cranks, characterized in that a second crank is deflected rotationally in a different direction than a first crank.
2. High-voltage circuit breaker system according to Claim 1, characterized in that the crankshaft (10) performs a unidirectional rotational movement (16) in relation to its axis of rotation (30) of between 150° and 210° from a closing position (26) of the contact system (14) to an opening position (28) of the contact system.
3. High-voltage circuit breaker system according to Claim 1 or 2, characterized in that the crankshaft (10) performs a unidirectional rotational movement (16) in relation to its axis of rotation (30) of between 350° and 360° + 10° for an opening movement (20) and closing movement (22) of the contact system (4).
4. High-voltage circuit breaker system according to one of the preceding claims, characterized in that the crankshaft (10) has a crankpin (32) that is eccentric in relation to the axis of rotation (30) on a crank (32), which crankpin describes a circular movement about the axis of rotation during the rotational movement (16) of the crankshaft.
5. High-voltage circuit breaker system according to Claim 4, characterized in that the crankpin (34) is oriented parallel to the axis of rotation (30).
6. High-voltage circuit breaker system according to Claim 5, characterized in that the crankpin (34) is encompassed by a sliding bearing (38) of the pushrod (38).

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