EP1630841B1 - Switching-chamber and high-power circuit-breaker - Google Patents

Abstract

The high power electrical switch has a movable contact [2] which when moved away from the fixed contact [1] causes arcing [4] to occur within a closed space. A heated space [11] provides heated gas to extinguish the arc. The formed body serves to guided the gas to the arcing region. The maximum relative velocity of contact separation is set to aid the process.

Description

Technical area

The invention relates to the field of high voltage switch technology. It relates to a switching chamber for a high-performance switch and a high-performance switch and to a method for switching off a switching chamber according to the preamble of the independent claims.

State of the art

From the prior art are filled with a quenching gas high-performance switch with a switching chamber is known which has two arcing contact pieces, of which at least one is movable by means of a drive. After a contact separation burns an arc between the two arcing contact pieces. A boiler room is provided for temporary storage of arc gas heated by the arc. An insulating nozzle has to guide a quenching gas flow connected to the boiler room Engle. This will be a blowing reaches the arc, which should lead to its extinction, so that a current flowing through the high-power switch can be switched.

After the contact separation, a relative movement of the two arcing contact pieces takes place in order to remove them rapidly from one another, since otherwise a so-called re-ignition can take place due to the so-called recurring voltage which rises immediately after extinguishment of the arc. If a reignition, so was not switched.

This so-called capacitive switching thus requires a high relative speed of the two arcing contact pieces. A relative speed of the two arcing contact pieces necessary for capacitive switching (minimum) can be determined experimentally or by model calculations.

In known from the prior art high-performance switches and switching chambers, the relative speed of the two arcing contact pieces is selected such that it meets the minimum requirements of the capacitive switching, optionally with a safety margin of a few percent.

Since capacitive switching places the highest demands on the relative speed of the two arcing contact pieces in the case of the high-power switches known from the prior art, no appreciably higher relative speeds were realized, since this would have required a more complex design of the heavy-duty circuit breaker and, in particular, correspondingly stronger drives and damping devices, without providing any noticeable advantage.

Typical maximum relative speeds of the arcing contact pieces are between 5 m / s and 9 m / s.

Out EP 1 211 706 A1 is a high-performance switch with two movable arcing contact pieces known, with a maximum speed ratio of the two contact pieces is achieved in the opposite direction of movement from 1: 1.6 to 1: 1.7.

In switching chambers and high-performance switches of the type mentioned, it is always desirable to achieve a stronger arc blowing.

From the Scriptures DE 100 03 359 C1 For example, a high power switch is known with two movable arcing contact pieces and a heating chamber for temporarily storing quenching gas, which has been heated by an optionally burning between the arcing contact pieces arc. The switch has an insulating nozzle, which has a throat for guiding a quenching gas flow, which in turn is connected by means of a channel with the heating chamber. First, the two contact pieces move in the opposite direction, wherein the contact separation takes place and the Engnis is at least partially dammed by the second of the two contact pieces. While the throat is still at least partially closed by the second contact piece, there is a reversal of the movement of the second contact piece. The second contact piece then moves in the same direction as the first of the two contact pieces. Due to the fact that the throat is still at least partially blocked by the second contact piece during the reversal of the direction of movement, an increase of the quenching gas pressure in the heating chamber can be generated. As a result, a stronger arc blowing can be achieved.

Presentation of the invention

It is an object of the invention to provide an alternative possibility for generating a particularly effective arc blowing.

This object is achieved by a device and a method having the features of the independent patent claims.

A switching chamber according to the invention for a high-power switch which can be filled with an extinguishing gas has a first arcing contact piece and a second arcing contact piece, of which at least one is movable by means of a drive. If necessary, an arc burns between the arcing contact pieces. The switching chamber comprises a heating chamber for temporarily storing extinguishing gas heated by the arc, and an insulating nozzle which has a throat connected to the heating chamber for guiding an extinguishing gas flow.

According to a first aspect of the invention, the switching chamber according to the invention is designed such that during a switch-off operation, a maximum relative velocity v _{12, max of} the two arcing contact pieces is at least 1.3 times greater than a relative velocity v _{12, c of} the two arcing contact pieces necessary for the capacitive switching.

In particular, the inventive switching chamber can be designed such that during a turn-off, the maximum relative speed v _{12, max of} the two arcing contact pieces to each other at least 1.5 times, preferably at least 1.7 times large, advantageously at least 1.9 times as large or even at least twice as large as the relative speed v _{12, c of} the two arcing contact pieces necessary for the capacitive switching.

The speed v _{12, c} is the minimum required for capacitive switching relative speed of the two arcing contact pieces, so the smallest relative speed of the two arcing contact pieces, the capacitive switching allows.

insbesondere $${\mathrm{v}}_{12,\max }\ge 27\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{E}}_{\mathrm{krit}}\cdot {\mathrm{p}}_0\right),$$

vorteilhaft $${\mathrm{v}}_{12,\max }\ge 31\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{E}}_{\mathrm{krit}}\cdot {\mathrm{p}}_0\right),$$

wobei
U_N die Nennspannung des Hochleistungsschalters,
p der Polfaktor des Hochleistungsschalters,
E_krit die Einsatzfeldstärke für Entladungen des Löschgases, und
po der Fülldruck des Löschgases ist, und
f die Netzfrequenz ist, für die Schaltkammer ausgelegt ist.In another aspect, the invention may consist in that the switching chamber is designed such that, if it is installed in a single-chamber high-power switch, for the maximum relative speed v _{12, max of} the two arcing contact pieces to each other during a turn-off: $${\mathrm{<figure-callout\; id="12"\; label="v"\; filenames="imgf0001.png"\; state="\{\{state\}\}">v</figure-callout>}}_{12.\mathrm{Max}}\ge 23\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{e}}_{\mathrm{crit}}\cdot {\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}}_0\right).$$

especially $${\mathrm{v}}_{12.\mathrm{Max}}\ge 27\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{e}}_{\mathrm{crit}}\cdot {\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}}_0\right).$$

advantageous $${\mathrm{v}}_{12.\mathrm{Max}}\ge 31\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{e}}_{\mathrm{crit}}\cdot {\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}}_0\right).$$

in which
U _{N is} the rated voltage of the heavy-duty circuit breaker,
p the pole factor of the high-power switch,
E _crit the field strength for discharges of the extinguishing gas, and
po is the filling pressure of the extinguishing gas, and
f is the mains frequency, is designed for the switching chamber.

gibt in guter Näherung die für kapazitives Schalten notwendige minimale Maximal-Geschwindigkeit zwischen den beiden Lichtbogenkontaktstücken an, wobei der Faktor k typischerweise zwischen 16 und 18.5 liegt.the equation $${\mathrm{v}}_{}$$$${\mathrm{}}_{12.\mathrm{c}}\approx \mathrm{k}\times {\mathrm{U}}_{\mathrm{N}}\cdot \mathrm{p}\cdot \mathrm{f}/\left({\mathrm{e}}_{\mathrm{crit}}\cdot {\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}}_0\right).$$

gives, to a good approximation, the minimum maximum speed required for capacitive switching between the two arcing contact pieces, wherein the factor k is typically between 16 and 18.5.

The aforementioned equations / inequalities for v _{12, c} and v _{12, max also} apply in the illustrated form to a high-power switch which has exactly one corresponding switching chamber. For the calculation of v _{12, c} and v _{12, max} for a high-power switch, which has more than one switching chambers, a factor must be inserted into the equations (or the factor k is replaced by a factor k '), whereby the taxation of the high-power switch (for example, by connected in parallel to the switching chambers capacity).

For SF ₆ as extinguishing gas, E _{crit is} about 8900 kV / (bar · m). For other extinguishing gases such as CF ₄ or mixtures of SF ₆ and N ₂ , the corresponding E _crit value can be found in the relevant manuals. Typical line frequencies are 50 Hz and 60 Hz. Fill pressures po are typically 4.3 bar or 6 bar or above. The pole factor p depends on the intended earthing conditions of the high-performance switch in the high-voltage network (see, for example, the IEC 62271-100 standard) and is typically 1.4 or 1.2, and occasionally more than 1.4. Typical high-voltage switch rated voltages U _N are of the order of 123 kV or 365 kV.

vorteilhaft $${\mathrm{v}}_{12,\max }\ge 15\mathrm{m}/\mathrm{s},$$

insbesondere $${\mathrm{v}}_{12,\max }\ge 17\mathrm{m}/\mathrm{s},$$

besonders vorteilhaft $${\mathrm{v}}_{12,\max }\ge 19\mathrm{m}/\mathrm{s},$$

In another aspect, the invention may consist in that the switching chamber is designed such that for the maximum relative speed v _{12, max of} the two arcing contact pieces to each other during a turn-off operation: $${\mathrm{<figure-callout\; id="12"\; label="v"\; filenames="imgf0001.png"\; state="\{\{state\}\}">v</figure-callout>}}_{12.\mathrm{Max}}\ge 13\mathrm{m}/\mathrm{s}.$$

advantageous $${\mathrm{v}}_{12.\mathrm{Max}}\ge 15\mathrm{m}/\mathrm{s}.$$

especially $${\mathrm{v}}_{12.\mathrm{Max}}\ge 17\mathrm{m}/\mathrm{s}.$$

especially advantageous $${\mathrm{v}}_{12.\mathrm{Max}}\ge 19\mathrm{m}/\mathrm{s}.$$

The invention makes it possible to produce a very large arc gap within a very short time. Advantageously, during a substantial part of the arc time (arc burning time), material from the insulating nozzle can be vaporized by the arc along a large part of the throat, advantageously along the entire length of the throat. A large surface, in particular the entire inner surface of the throat, can thus be used for a relatively long period of time for the generation (vaporization) of arc-extinguishing material. As a result, a large amount of arc-quenching material is generated, so that an efficient arc blowing is achieved. Due to the very rapid relative movement, this large amount of arc-quenching material can already be generated within a very short time, so that a very large quenching gas pressure can be generated, and the pressure generation can take place very quickly after the contact separation. As a result, a very strong arc blowing and thus a very safe switching, even large short-circuit currents can be achieved.

Advantageously, the movement of the insulating nozzle is coupled to the movement of one of the two contact pieces, in particular rigidly coupled (equally fast and rectified movement of the insulating nozzle and of the relevant contact piece). Advantageously, the relative speed between the insulating nozzle and one of the two contact pieces satisfies one of the abovementioned conditions according to the invention for the maximum relative speed v _{12, max of} the two contact pieces.

If the throat is at least partially dammed by one of the two arcing contact pieces, which is referred to as Verdämm contact piece and is movable, so the two arcing contact pieces advantageously until at least the time of release of the passage through the Verdämm contact piece (that is, therefore, at least to one Extinguishing gas flow through the throat is possible), such a relative speed, which satisfies one of the above conditions for v _{12, max} . This relative speed may be the maximum relative speed v _{12, max of} the arcing contact pieces or also a relative speed which is less than v _{12, max} .

In another aspect, the invention may be that the switching chamber is designed such that both arcing contacts are movable, and that during a phase of opposite movement of the arcing contact pieces a ratio v1 / v2 of the speed v1 of the first arcing contact to the speed v2 of
second arcing contact piece of v1 / v2 ≤ 1: 2.4, in particular of v1 / v2 ≤ 1: 2.7, v1 / v2 ≤ 1: 2.8 or v1 / v2 ≤ 1: 3 is achieved. By such a speed ratio, a large relative speed of the arcing contact pieces can be achieved. This is particularly advantageous if the mass to be moved with the first arcing contact piece is significantly larger (at least by a factor of 2 or 3 or 4 or more) than the mass to be moved with the second arcing contact piece.

If both arcing contact pieces are movable, advantageously a first drive for driving the first arcing contact piece and a second drive for driving the second arcing contact piece are provided. In particular, the second drive (auxiliary drive) may be a drive drivable by the first drive. Advantageously, furthermore, the insulating nozzle can be driven by means of the first drive.

insbesondere $$0.75\le \mathrm{v}1/\mathrm{v}2\le 1:\mathrm{1.15.}$$

In the case of two movable arcing contact pieces, the switching chamber is advantageously designed such that in one phase during a rectified movement of the arcing contact pieces for the ratio v1 / v2 of the velocity v1 of the first arcing contact to the velocity v2 of the second arcing contact: $$0.4\le \mathrm{v}1/\mathrm{v}2\le 1.2.$$

especially $$0.75\le \mathrm{v}1/\mathrm{v}2\le 1:\mathrm{1.15.}$$

Particularly advantageously, the speed ratio v1 / v2 is between 0.9 and 1.1 or close to one or is substantially one.

In an advantageous embodiment, a compression space is present whose volume is reduced during a switch-off. It may be the compression chamber with the boiler room identical or different from the boiler room, and be provided in particular a valve between the compression space and the boiler room. The switch, or the switching chamber, may be configured as a buffer switch (blow piston switch) or as a self-blowing switch or as a buffer switch self-blowing switch hybrid.

The switching chamber may be advantageously designed so that during a turn-off, after the contact separation, and while a quenching gas flow along an axis through the throat in the direction of the second arcing contact piece is possible, a measured parallel to the axis distance d between the throat and the second Arc contact piece is selected such that the flow velocity of the quenching gas flow is at a maximum in such a region, which is arranged with respect to the axis radially laterally adjacent to the second arcing contact piece and / or within the second arcing contact piece. The area can be contiguous or consist of several subareas.

The distance d is a spacing. The distance d is of course measured between the ends of Engnis facing each other and the second contact piece when the throat and the second contact piece are spaced from each other.

By said choice of the distance d, an optimization of the extinguishing gas flow, in particular in the region of the throat and the second contact piece is achieved. The extinguishing gas flow is optimized so that a particularly high dielectric strength is generated where a particularly high dielectric load is present. This advantageous effect is achieved by the described choice of the distance d, since a high quenching gas density can be achieved along the switching path, while a lower quenching gas density in the dielectrically less loaded area laterally (and / or inside) of the second contact piece is present.

gilt. Dabei ist D der Durchmesser des Zylinders nahe dem während der Löschphase dem zweiten Lichtbogenkontaktstück zugewandten Ende des Zylinders, der Winkel α ist gleich einem Öffnungswinkel α eines an das Engnis anschliessenden, erweiterten Bereiches, und für den Parameter b' gilt: b' = b - F/F', wobei F' der Flächeninhalt der bezüglich der Achse radial angeordneten Querschnittsfläche einer gegebenenfalls in dem zweiten Kontaktstück vorgesehenen Öffnung zum Abströmen von Löschgas ist, und für den Parameter b gilt: $$1.4\le \mathrm{b}\le 4.5,$$

insbesondere $$1.7\le \mathrm{b}\le 4.0,$$

insbesondere $$2.1\le \mathrm{b}\le 3.5,$$

und besonders vorteilhaft $$2.2\le \mathrm{b}\le 3.2,$$

Advantageously, the throat may be substantially configured as a cylinder, and the switching chamber may be configured to be parallel during a turn-off operation, after contact separation, and during a quenching phase in which quench gas flow along an axis through the throat is possible in the direction of the second arcing contact is selected to the axis distance d between the throat and the second arcing contact piece such that $$\mathrm{d}=\mathrm{D}\times \left({\left(1+{\mathrm{b}}^{\text{'}}\cdot \cos \mathrm{<figure-callout\; id="1"\; label="\alpha "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\alpha </figure-callout>}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}-1\right)/\left(2\cdot \sin \mathrm{\alpha }\cdot \cos \mathrm{\alpha }\right)$$

applies. In this case, D is the diameter of the cylinder near the end of the cylinder facing the second arcing contact during the extinguishing phase, the angle α is equal to an opening angle α of an extended region adjoining the throat, and the following applies for the parameter b ': b' = b - F / F ', where F' is the area of the radial cross-sectional area of an axis, optionally arranged in the second contact piece, for discharging extinguishing gas, and for the parameter b: $$1.4\le \mathrm{b}\le 4.5.$$

especially $$1.7\le \mathrm{b}\le 4.0.$$

especially $$2.1\le \mathrm{b}\le 3.5.$$

and especially advantageous $$2.2\le \mathrm{b}\le 3.2.$$

The throat is formed substantially cylindrical, and advantageously the second contact piece is also formed substantially cylindrical. The diameter of the respective cylinder (the throat or the second contact piece) does not have to be completely constant and can vary slightly. Deviations from a circular cross section to, for example, elliptical cross sections are possible. The throat (or the second contact piece) may have another, advantageously substantially prismatic shape and is still referred to as substantially cylindrical. For the diameter D, a corresponding radial dimension of the throat is then taken. In particular, the diameter of such a circle can be taken with good accuracy, which has the same area as the throat near the second contact piece. Also, the diameter of the cylinder or the radial dimension of the prism must not be exactly constant. The relevant quantity for the determination of d is the radial dimension at the end of the cylinder or prism facing the second contact piece. Such forms are also included in the term "substantially cylindrical".

Due to the described cylinder diameter-dependent choice of the distance d, the mentioned advantageous flow rate condition is fulfilled for the common switch geometries. If the distance d can be kept within a narrower of the specified ranges for d, maintenance of the advantageous extinguishing gas flow can be better ensured.

Thus, there is a period of time, referred to as the quenching phase, which occurs after the contact separation, and during which an extinguishing gas flow through the throat can take place in the direction of the second arcing contact piece (and also takes place in the case of switching). During such a period of time, the distance d satisfies the condition mentioned. This condition is that the region in which the flow velocity of said quenching gas flow directed through the throat toward the second contact piece is greatest is located within the second contact piece and / or laterally adjacent to the second contact piece.

While the throat is at least partially insulated with a contact piece which can be designated as a damming contact piece, no (notable) extinguishing gas flow can take place through the throat.

The said condition for the distance d is advantageously fulfilled for at least 10 ms, more advantageously for at least 20 ms, at least 35 ms or at least 50 ms during a switch-off operation.

The Engnis can also be called a nozzle channel.

The contact separation means a separation of physical contact between the two arcing contact pieces 1 and 2. The physical contact can be realized, for example, by contacting the contact pieces 1, 2 directly or by means of an intermediate contact piece contacting the two arcing contact pieces 1, 2. Contact pieces).

Advantageously, the second arcing contact piece is like a pin, in particular full pin-like design

In a preferred embodiment, the throat is at least partially deflatable by one of the two arcing contact pieces, which is referred to as Verdämm contact piece and is movable, and the switching chamber is designed such that during a Ausschaltvorganges there is a period during which a direction of movement of the Verdämm Contact piece remains unchanged and the maximum relative speed v _{12, max of} the two arcing contact pieces to each other is achieved. This period of time advantageously takes at least until the throat is no longer at least partially blocked by the damper contact piece.

Thus, in this embodiment, after the contact separation, there is an uninterrupted movement of the damper contact piece in one and the same direction, which movement stops at least until the throat is released by the damper contact piece, and (at some point) during this movement the maximum relative velocity v _{12, max of} the two arcing contact pieces to each other is achieved. This ensures that very quickly a very large insulating nozzle surface is exposed to the arc. Advantageously, no movement direction reversal of the Verdämm contact piece takes place before the Engnis is released.

A particularly preferred embodiment is characterized in that the Engnis by one of the two arcing contact pieces, which is referred to as Verdämm contact piece and is movable, is at least partially eingeschämmbar, and that the switching chamber is designed such that during a Ausschaltvorgangs a reversal of movement of the at least one movable arc contact piece takes place when the Engnis is no longer dammed by the Verdämm contact piece at least partially.

As a result, a large amount of arc-quenching material can be generated within a short time after the contact separation. And it is possible to reduce the load of a damping device braking the contact pieces or to use a less expensive damping device,

The movement direction reversal taking place after the release of the throat through the damper contact piece also makes it possible to optimize the quenching gas flow near the damper contact piece. Depending on the ratio of the speeds of the two contact pieces, the distance between the two contact pieces can be (slightly) increased or reduced or, with particular advantage, kept substantially constant. In particular, a distance between the damper contact piece and the throat can be (slightly) increased or reduced or, particularly advantageously, kept substantially constant. If, for example, the movement of the insulating nozzle 1: 1 (rigid) is coupled to the movement of the first contact piece and the rectified after the movement direction reversal movement of the two contact pieces is also substantially the same size, a predetermined distance between the throat and the Verdämm contact piece in kept substantially constant. In particular, and with great advantage, one of the conditions mentioned above for the distance d over a longer period of time can also be met.

As a result of the reversal of motion, an initially antiparallel or opposite movement of the two arcing contact pieces becomes a parallel or equidirectional movement of the two arcing contact pieces.

In particular, if a driven by the drive gear is used as an auxiliary drive (second drive), in the choice of a Velocity ratio v1 / v2 of the speed v1 of the first arcing contact piece to the speed v2 of the second arcing contact piece of v1 / v2 ≈ 1: 1 in the same direction contact piece movement a constant contact piece spacing (and optionally also a constant distance between the throat and the Verdämm contact piece ), which remains constant even when the switch movement is decelerated by a damper mechanism. Also, in this way the influence of return to said distances can be substantially eliminated. Return occurs when the movement of a driven contact piece is hindered by quenching gas in the boiler room, so that thereby takes place an unintended reversal of movement of at least one of the contact pieces.

By means of the motions reversal selectively generated by the drives can thus be achieved in such a high-performance switch or switch pole good control of the contact piece distances and the Engnis contact piece distance, so that desired flow conditions, especially near the Verdämm contact piece, adjustable and also in different Switching cases are sustainable. An optimization of the quenching gas flow near the contact piece is made possible.

A high-performance switch according to the invention has at least one switching chamber according to the invention and has the corresponding advantages.

The method according to the invention for switching off a switching chamber for a high-power switch that can be filled with a quenching gas, with a first arcing contact piece and with a second arcing contact piece, with at least one drive and with an insulating nozzle having a throat, has the steps that at least one of the two arcing contact pieces by means of Drive is moved, that a contact separation takes place and an arc burning between the arcing contact pieces is ignited, is heated by the quenching gas, and that the heated quenching gas is cached and led to the blowing of the arc through the Engnis.

It is characterized in that during a turn-off operation, a maximum relative speed v _{12, max of} the two arcing contact pieces is achieved, which is at least 1.3 times, in particular 1.5 times as large as a relative speed v _{12, c of} the two arcing contact pieces necessary for capacitive switching. The advantages arise from the advantages of the switching chamber.

The inventive method can also be referred to as a method for switching an electric current by means of a switching chamber.

Advantageously, the two arcing contact pieces are arranged coaxially with each other. The channel between the boiler room and Engnis can be advantageously designed as an annular channel.

The arcing contact pieces can also be rated current contacts at the same time. Advantageously, however, separate rated current contacts are provided in addition to the arcing contact pieces. Typically, in a turn-off operation, first the rated current contacts are separated from each other so that the electrical current to be interrupted commutes to the arcing contact pieces. Thereafter, the arc contact pieces are separated with ignition of the arc.

Advantageously, one of the two arcing contact pieces, in particular the first arcing contact piece, have an opening for receiving the other, advantageously pin-shaped arcing contact piece in the closed switch state and for discharging extinguishing gas in the opened switch state. In particular, this arc contact piece may be formed as a contact tulip with a plurality of contact fingers.

It is advantageous if the second arcing contact piece is formed like a pin and is movable while the first contact piece has an opening for receiving the second contact piece, and is movable or not movable.

High-performance switches and switching chambers in the sense of this application are, in particular, those which are designed for nominal voltages of typically at least approximately 72 kV.

The arc in a switching chamber according to the invention generally burns close to the axis and is substantially stationary. In general, the base points of the arc are fixed to the ends of the arcing contact pieces.

Further preferred embodiments and advantages emerge from the dependent claims and the figures.

Brief description of the drawings

Fig. 1

eine erfindungsgemässe Schaltkammer mit zwei bewegbaren Lichtbogenkontaktstücken in geöffnetem und in geschlossenen Zustand im Schnitt, mit Getriebe in Aufsicht;

Fig. 2

eine Weg-Zeit-Kurve für einen Ausschaltvorgang;

Fig. 3

eine Geschwindigkeits-Zeit-Kurve für einen Ausschaltvorgang.

In the following, the subject invention will be explained in more detail with reference to preferred embodiments, which are illustrated in the accompanying drawings. They show schematically:

Fig. 1

an inventive switching chamber with two movable arcing contact pieces in the open and closed state in section, with gear in supervision;

Fig. 2

a path-time curve for a turn-off;

Fig. 3

a speed-time curve for a switch-off process.

The reference numerals used in the drawings and their meaning are listed in the list of reference numerals. Basically, the same or equivalent parts are provided with the same reference numerals in the figures. The described embodiments are exemplary of the subject invention and have no limiting effect.

Ways to carry out the invention

Fig. 1 schematically shows an inventive switching chamber or a novel single-chamber high-performance switch in the open state (lower half) and in the closed state (upper half). In the right part of the picture, a gear 3 is shown schematically in plan. The high-power switch filled with a quenching gas (for example SF ₆ , or a mixture of N ₂ and SF ₆ ) has a first movable arcing contact piece 1, which is driven by a non-illustrated drive is drivable. A suitable drive can be, for example, an electrodynamic drive or a spring-loaded drive.

A second arcing contact piece 2 is driven by an auxiliary drive 3, which is realized by the drive 3 driven by the drive. In the closed switch state, the two arcing contacts 1.2 touch each other. It may additionally be provided not shown nominal current contact pieces.

The first contact piece 1 is rigidly connected to an insulating nozzle 5 and an auxiliary nozzle 13. The insulating nozzle 5 has a throat 6, which is formed substantially cylindrical with a diameter D. Subsequent to the throat 6, a diameter-extended area 21 with an opening angle α adjoins. Through an annular channel 7, the Engnis is connected to a boiler room 11. Connected to the heating chamber 11 through a valve 12 is a compression space 10. The volume of the heating space is variable by means of a piston 15, which is advantageously fixed.

The high-power switch is formed substantially rotationally symmetrical with respect to an axis A, whereby axial directions z1 and z2 along which the arcing contact pieces move and vertical radial directions are defined.

In Fig. 2 schematically a path-time diagram (zt curves) for the movement of the first contact piece 1 (dashed curve) and the second contact piece 2 (dotted curve) and for the relative movement of the two contact pieces (solid line) is shown.

The corresponding velocity-time curves (vt curves) are in Fig. 3 shown schematically. The speed v1 of the first contact piece 1 (dashed curve) and the speed v2 of the second contact piece 2 (dotted curve) and the relative speed v12 of the two contact pieces (solid line) are shown.

During a turn-off operation for interrupting a current flowing through the high-power switch, the first arc contact piece 1 and the insulating nozzle 5, the auxiliary nozzle 13 and the valve 12 first move in the direction z1. With an optional delay, the second contact piece 2 moves in the direction z2. The mass to be moved directly by the drive is large in relation to the mass to be moved by the gear 3. Up to shortly before reaching the maximum speed v1 can be waited therefore with the acceleration of the second contact piece 2. The first contact piece 1 remains after reaching its maximum speed up to a deceleration process at the end of the switch-off at this speed.

By the fixed piston 1 5, the volume of the compression chamber is reduced, and the valve 12 can quenching gas flow into the heating chamber 10. Then, during a phase of high or maximum relative speed v12, the contact separation takes place with the ignition of an arc 4. It is possible that the contact separation takes place shortly (a few milliseconds) before or after reaching the maximum relative speeds.

The arc 4 leads to the heating of quenching gas and dissolves in Engnis 6 burn-off material from the insulating 5 out. By means of the annular channel 7, an overpressure in the heating chamber 11 is generated in this way. From a presettable by the valve 12 pressure difference between the heating chamber 11 and the compression chamber 10, for example, if in the heating chamber 11, a greater pressure prevails than in the compression chamber 10, closes the valve 12. The later from the boiler room 11 and possibly also from the compression chamber 10 through the boiler room 11 then through the channel 7 in between the two Contact pieces 1.2 arranged extinguishing path flowing extinguishing gas is then used to extinguish the arc. 4

After the end of the second arcing contact piece 2 facing the first arcing contact piece 1 has traversed the greater part (approximately 80%) of the length of the throat 6 at maximum speed v2 (and thus during the presence of the maximum relative speed v12 _{, max of} the two arcing contact pieces) get v2 again. The second contact piece 2 comes to a standstill and, after it has released the throat 6, moves in the direction z1 and thus parallel to (rectified with) the first contact piece 1. After this direction of movement reversal, the second contact piece 2 soon reaches the same speed as the first one Contact piece 1.

As soon as the throat 6 is no longer at least partially blocked by the second contact piece 2, quenching gas can flow through the channel 7 not only through the tulip-shaped first contact piece 1 (in the direction z1) but also (to a considerable extent) through the throat 6 and on the pin-shaped second one Pull contact piece 2 past (in the direction of z2).

By the speed ratio v1 / v2 of substantially 1: 1 in the same direction movement of the two contact pieces 1,2, a distance d between the second, advantageously pin-shaped contact piece 2 and the throat 6 can be kept substantially constant. This distance d is chosen such that, in the case of an extinguishing gas flow through the throat 6 to the damper contact piece 2 (in the direction z 2), the maximum Flow rate laterally (ie radially) adjacent to the Verdämm contact piece 2, and in particular not on the route between the two arcing contact pieces 1 and 2 (or radially adjacent to this distance). As a result, a particularly efficient arc blowing is achieved, and a re-ignition of the arc is effectively prevented. The distance d is chosen as d ≈ (0.7 ± 0.2) × D, where D is the diameter of the throat 6 (at its z2-sided end). If the opening angle α were smaller than 45 °, then the distance d would advantageously be selected approximately as d≈ (0.7 ± 0.2) × D / tan α.

If a speed ratio v1 / v2 of 1: 1 (after the reversal of the direction of rotation) is predetermined by the gearbox 3, the distance d and thus also the corresponding flow conditions can be maintained even if the switch goes into damping, ie the contact pieces 1, 2 are braked by a damping mechanism. Towards the end of a switch-off process, there is often also a return of the first contact piece 1 caused by the pressure conditions in the heating chamber 11 and / or the compression chamber 10. Also by such a return, when a speed ratio v1 / v2 of 1: 1 is selected, the distance d not be changed. In this respect, optimum flow conditions can be maintained until the end of the switch-off movement, thereby ensuring safe arc extinguishment without backflushing. Due to the speed ratio v1 / v2 of 1: 1, the distance between the two contact pieces 1 and 2 is constant, so that the electric field distribution is constant.

By a speed ratio v1 / v2 of about 1: 1 after the reversal of the direction of travel, it is possible to reduce the load of the damper or a less expensive one Damping device to use, as a longer damping stroke (longer distance during which the movements are braked) can be provided. Because after an early reaching a sufficient (typically almost maximum) distance between the arcing contact pieces, the braking of the contact pieces can already begin because the contact piece distance is kept constant by the 1: 1 ratio. For a speed ratio v1 / v2 which is close to one, in principle the same applies, but small changes in the contact piece spacing occur.

The Figs. 2 and 3 show the movements of the contact pieces 1,2 only until shortly after the use of damping. With P1 is designated a first phase, during which there is a maximum relative speed v12 with opposite movement of the two contact pieces 1,2. In the case shown this is v _{12, max} ≈ 20 m / s. With P2 a second phase is designated, during which there is a speed ratio v1 / v2 of about 1: 1 in the same direction movement of the two contact pieces 1,2 after release of the throat. In the Figs. 2 and 3 If the end of the second phase P2 coincides with the use of damping.

Like the right part of Fig. 1 can be seen (in plan view), a lever 8 is rotatably mounted at a first end by means of a bolt 16 on the second contact piece 2. At the second end of the lever 8, the lever 8 is rotatably supported by a bolt 17 on a leg of an angle lever 9. The second leg of the angle lever 9 is guided by means of a bolt 18 in a link plate 14. The angle lever 9 is rotatably supported by means of a stationary, for example, attached to the housing of the high-power switch pin 19. As symbolized by means of a line of action W, the movement of the link plate 14 (preferably rigidly) is coupled to the movement of the first contact piece 1.

By connected to the drive crank plate 14 so the movement of the second contact piece 2 is controlled by a lever mechanism. The transmission 3 can convert a linear movement (of the drive) with a constant speed into a movement with reversal of the direction of movement. By a suitable choice of lever lengths and angles, a desired speed profile for the second contact piece 2 can be selected.

The transmission 3 can, as in Fig. 1 shown to be symmetrical, resulting in a more favorable distribution of forces and greater stability.

By reducing the speed v2 of the second contact piece 2 at the end of the switch-off movement, the load on a damping device that decelerates the movement of the contact pieces can be reduced since a lower kinetic energy must be absorbed.

The speed v1 of the first contact piece 1 after the initial acceleration may typically be between 3 m / s and 10 m / s, for example 5 m / s. The speed v2 of the second contact piece 1 can typically be 10 m / s to 20 m / s at the maximum, for example 15 m / s. The maximum speed ratio v1 / v2 (with opposite motion) can be between 1: 2.4 and 1: 3.5, for example 1: 3. As a result, correspondingly large relative velocities v12 between typically 15 m / s, 20 m / s and more can be achieved, which enable rapid release of the throat 6 and efficient arc blowing by providing a large quenching gas pressure within a short time. A large distance between the contact pieces 1 and 2 (Isolierstrecke) can be achieved within a very short time.

Advantageously, the throat 6 and also the second contact piece 2 is formed substantially cylindrical. The diameter of the respective cylinder (the throat or the second contact piece) does not have to be completely constant and can vary slightly. Deviations from a circular cross section to, for example, elliptical cross sections are possible.

In this way, when the throat has a large length (axial extent), a very large surface of the insulating nozzle can be exposed to the arc, whereby large amounts of material can be evaporated from the insulating nozzle, so that an efficient arc blowing is achieved. In particular, throat lengths of more than 40 mm, advantageously more than 50 mm and more than 60 mm can be used.

A corresponding high-performance switch can be designed for rated cur- rent currents of more than 40 kA or more than 50 kA at nominal voltages of more than 170 kV or over 200 kV.

LIST OF REFERENCE NUMBERS

1

first arcing contact piece

2

second arcing contact piece, damper contact piece

3

second drive, auxiliary drive, gearbox

4

Electric arc

5

insulating

6

throat

7

Channel, ring channel

8th

lever

9

bell crank

10

compression chamber

11

boiler room

12

Valve

13

auxiliary nozzle

14

Scenery, backdrop

15

piston

16,17,18

Bolt, rotatable bearing

19

fixed bolt, rotatable bearing

21

Range, (in radius) extended range

A

Axis, axis of symmetry

b, b '

parameter

d

distance

D

Diameter, radial dimension

k

factor

P1

phase

P2

phase

v1

Speed of the first contact piece

v2

Speed of the second contact piece

v12

Relative speed of the contact pieces

v _{12, c}

for capacitive switching minimum necessary relative speed of the contact pieces

v _{12, max}

maximum relative speed of the contact pieces

W

line of action

z

Way coordinate

z1

direction

z2

direction

α '

angle

α

opening angle

Claims (18)

1. Switching chamber for a heavy-duty circuit breaker which is filled with a quenching gas, having a first arcing contact piece (1) and a second arcing contact piece (2), of which at least one (1; 2) can be moved by means of a drive, having an arc (4) which may burn between the arcing contact pieces (1, 2), having a heating space (11) for temporarily storing quenching gas heated by the arc (4), and having an insulating nozzle (5), which has a throat (6), which is connected to the heating space (11), for the purpose of guiding a quenching gas flow, characterized in that, during an opening operation, a maximum relative speed v-_12,max of the two arcing contact pieces (1, 2) in relation to one another is at least 1.3 times as great as a relative speed v_12,c of the two arcing contact pieces (1, 2) which is required for capacitive switching and in that the switching chamber is designed in such a way that, when it is installed in a single-chamber heavy-duty circuit breaker, the following applies for the maximum relative speed v_12,max of the two arcing contact pieces (1, 2) in relation to one another during an opening operation: v_12,max ≥ 23 × U_N·p·f/(E_crit·p₀), where U_N is the rated voltage of the heavy-duty circuit breaker, p is the pole factor of the heavy-duty circuit breaker, E_crit is the threshold field strength for discharges of the quenching gas, and p₀ is the filling pressure of the quenching gas, and f is the high-voltage system frequency for which the switching chamber is designed, with the result that a high quenching gas pressure can be generated.
2. Switching chamber according to Claim 1, characterized in that, during an opening operation, the maximum relative speed v_12,maX of the two arcing contact pieces (1, 2) in relation to one another is at least 1.5 times as great as the relative speed v_12,c of the two arcing contact pieces (1, 2) which is required for capacitive switching.
3. Switching chamber according to one of the preceding claims, characterized in that the following applies for the maximum relative speed v_12,max of the two arcing contact pieces (1, 2) in relation to one another during an opening operation: $${\mathrm{v}}_{\mathrm{12}\mathrm{,}\max }\mathrm{\ge }13\mathrm{m}\mathrm{/}\mathrm{s},$$

   

   
   in particular $${\mathrm{v}}_{\mathrm{12}\mathrm{,}\max }\mathrm{\ge }\mathrm{17}\mathrm{m}\mathrm{/}\mathrm{s}\mathrm{.}$$

   
4. Switching chamber according to one of the preceding claims, characterized in that both arcing contact pieces (1, 2) are moveable, and in that, during a phase (P1) of movement in opposite directions of the arcing contact pieces (1, 2), a ratio v1/v2 of the speed v1 of the first arcing contact piece (1) to the speed v2 of the second arcing contact piece (2) of v1/v2 ≤ 1:2.4, in particular of v1/v2 ≤ 1:2.8, is achieved.
5. Switching chamber according to one of the preceding claims, characterized in that a compression space (10) is provided whose volume is reduced during an opening operation.
6. Switching chamber according to Claim 5, characterized in that the compression space (10) is different than the heating space (11), and in that a valve (12) is provided between the compression space (10) and the heating space (11).
7. Switching chamber according to one of the preceding claims, characterized in that both arcing contact pieces (1, 2) are moveable, and in that a first drive for driving the first arcing contact piece (1) and a second drive (3) for driving the second arcing contact piece (2) are provided.
8. Switching chamber according to Claim 7, characterized in that the second drive (3) is a transmission (3) which can be driven by the first drive.
9. Switching chamber according to Claim 7 or 8, characterized in that the insulating nozzle (5) can be driven by means of the first drive.
10. Switching chamber according to one of Claims 7-9, characterized in that, in a phase (P2) during a movement in the same direction of the arcing contact pieces (1, 2), the following applies for the ratio v1/v2 of the speed v1 of the first arcing contact piece (1) to the speed v2 of the second arcing contact piece (2):
    0.4 ≥ v1/v2 ≥ 1.2, in particular 0.75 ≥ v1/v2 ≥ 1: 1.15.
11. Switching chamber according to one of the preceding claims, characterized in that, during an opening operation, after the contact separation and while a quenching gas flow along an axis (A) through the throat (6) in the direction (z2) of the second arcing contact piece (2) is possible, a distance d, which is measured parallel to the axis (A), between the throat (6) and the second arcing contact piece (2) is selected such that the flow rate of the quenching gas flow is at a maximum in a region which is arranged, with respect to the axis (A), radially and laterally next to the second arcing contact piece (2) and/or within the second arcing contact piece (2).
12. Switching chamber according to one of the preceding claims, characterized in that the throat (6) is essentially in the form of a cylinder, and in that, during an opening operation, after the contact separation and during a quenching phase, in which a quenching gas flow along an axis (A) through the throat (6) in the direction (z2) of the second arcing contact piece (2) is possible, a distance d, which is measured parallel to the axis (A), between the throat (6) and the second arcing contact piece (2) is selected such that
    d = D × ( (1 + b'·cosα)^½ - 1) / (2·sinα·cosα) applies, where D is the diameter of the cylinder close to that end of the cylinder which faces the second arcing contact piece (2) during the quenching phase, and where α is equal to an opening angle α of an extended region (21) adjoining the throat (6), and where the following applies for the parameter b': b' = b - F/F', where F' is the area of the cross-sectional area, which is arranged radially with respect to the axis (A), of an opening, which may be provided in the second contact piece (2), for quenching gas to flow away, and where the following applies for the parameter b: $$\mathrm{1.4}\mathrm{\le }\mathrm{b}\mathrm{\le }\mathrm{4.5},$$

    

    
    in particular $$\mathrm{1.7}\mathrm{\le }\mathrm{b}\mathrm{\le }\mathrm{4.0.}$$

    
13. Switching chamber according to Claim 11 or 12, characterized in that the condition mentioned for the selection of the distance d is met in at least 10 ms, in particular in at least 35 ms.
14. Switching chamber according to one of the preceding claims, characterized in that the second arcing contact piece (2) is in the form of a pin.
15. Switching chamber according to one of the preceding claims, characterized in that the throat (6) can be blocked at least partially by one of the two arcing contact pieces (1; 2), which is referred to as the blocking contact piece (2) and is moveable, and in that, during an opening operation, there is a time span during which a movement direction (z2) of the blocking contact piece (2) remains unchanged and the maximum relative speed v_12,max of the two arcing contact pieces in relation to one another is reached, and this time span lasts at least until the throat (6) is no longer at least partially blocked by the blocking contact piece (2).
16. Switching chamber according to one of the preceding claims, characterized in that the throat (6) can be blocked at least partially by one of the two arcing contact pieces (1; 2), which is referred to as the blocking contact piece (2) and is moveable, and in that, during an opening operation, a movement direction reversal of the at least one moveable arcing contact piece (2) takes place if the throat (6) is no longer at least partially blocked by the blocking contact piece (2) .
17. Heavy-duty circuit breaker, characterized in that the heavy-duty circuit breaker has at least one switching chamber according to one of the preceding claims.
18. Method for opening a switching chamber for a heavy-duty circuit breaker which is filled with a quenching gas, having a first arcing contact piece (1) and having a second arcing contact piece (2), having at least one drive and having an insulating nozzle (5), which has a throat (6), at least one of the two arcing contact pieces (1, 2) being moved by means of the drive, a contact separation taking place, and an arc (4) burning between the arcing contact pieces (1, 2) being struck, by means of which arc quenching gas is heated, the heated quenching gas being temporarily stored and being guided through the throat (6) for the purpose of blowing the arc (4), characterized in that, during an opening operation, a maximum relative speed v_12,max of the two arcing contact pieces (1, 2) in relation to one another is reached which is at least 1.3 times as great as a relative speed v_12,c of the two arcing contact pieces (1, 2) which is required for capacitive switching, and in that, if the switching chamber is installed in a single-chamber heavy-duty circuit breaker, the following applies for the maximum relative speed v_12,max of the two arcing contact pieces (1, 2) in relation to one another during an opening operation: V_12,max ≥ 23 × U_N·p·f/(E_crit·p₀), where U_N is the rated voltage of the heavy-duty circuit breaker, p is the pole factor of the heavy-duty circuit breaker, E_crit is the threshold field strength for discharges of the quenching gas, and p₀ is the filling pressure of the quenching gas, and f is the high-voltage system frequency for which the switching chamber is designed, with the result that a high quenching gas pressure can be generated.

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