EP1107272B1 - Hybrid circuit breaker - Google Patents

Abstract

This hybrid circuit breaker has at least two series-connected arcing chambers which are operated by a common drive or by separate drives and are filled with different arc extinguishing media. Means are provided which ensure a sensible voltage distribution between the first and the second arcing chamber in the course of a switching process. At least one vacuum switching chamber having an insulating housing, is provided as the second arcing chamber. The aim is to provide a hybrid circuit breaker wich can be produced economically and which has high availability. This is achieved, inter alia, in that means are provided which ensure that the movement of the contacting arrangement of the first arcing chamber precedes the movement of the contact arrangement of the second arcing chamber during a disconnection process, and that the movement of the contacting arrangement of the second arcing chamber precedes the movement of the contact arrangement of the first arcing chamber during a connection process. The second arcing chamber is permanently bridged by a non-reactive resistor, which is in the form of a resistance coating applied to the inner wall or the outer wall of the insulating housing of the second arcing chamber.

Description

TECHNICAL AREA

The invention is based on a hybrid power switch according to the preamble of claim 1.

STATE OF THE ART

The document EP 0 847 586 B1 discloses a hybrid power switch which can be used in an electrical high-voltage network. This hybrid power switch has two series-connected extinguishing chambers, of which a first is filled with SF ₆ gas as extinguishing and insulating medium, and a second is designed as a vacuum interrupter chamber. The second quenching chamber is surrounded outside by SF ₆ gas. The main contacts of the two extinguishing chambers are actuated simultaneously via a lever mechanism by a common drive. Both extinguishing chambers have a power current path, in which the erosion-resistant main contacts are, and in parallel to a nominal current path, said nominal current path having only a single point of interruption. When switching off, the nominal current path is always interrupted first, whereupon the current to be switched commutes to the power current path. The power current path then carries the power on until its definitive shutdown.

In this hybrid circuit breaker burns when switching off always occurring arc in the vacuum interrupter chamber during the same period as in the gas-filled first quenching chamber, with the result that the main contacts of the vacuum interrupter chamber of a comparatively high and long-lasting current load and associated therewith are subjected to high wear , which requires comparatively frequent inspection work, whereby the availability of the hybrid circuit breaker is limited. This hybrid circuit breaker requires a comparatively high drive energy, since, depending on the switching principle used in the gas-filled first quenching chamber, the drive must wholly or partly generate the high gas pressure necessary for the intensive blowing of the arc. Such a particularly powerful designed drive is relatively expensive.

After the arc has extinguished, the recurring voltage occurring across this hybrid power switch is distributed to these extinguishing chambers in accordance with the self-capacitances of the two extinguishing chambers. This has the consequence that the second, designed as a vacuum interrupter chamber, quenching chamber is acted upon by a large proportion of the recurring voltage, so that this second quenching chamber ignites in the rise of the recurrent voltage. This ignition can occur several times when switched off. The ignition can cause unwanted oscillations in the high-voltage network associated with undesirable voltage increases. In addition, the burn-off contacts of the vacuum interrupter chamber are additionally claimed by the ignition, so that their life is shortened.

From the patent application DE 3 131 271 A1, a hybrid switch is known, in which the voltage distribution over the two switching chambers by means of a capacitor which is parallel to the first, isolated with a gas and blown Switching chamber is connected, and by means of a non-linear resistor which is connected in parallel to the second, designed as a vacuum switching chamber switching chamber. When the recurring voltage rises immediately after the arc has been interrupted, these two components ensure that the vacuum switching chamber is initially charged with the greater part of this recurrent voltage and holds it. Later, the first switching chamber then takes over the greater part of the applied voltage. These two components for controlling the voltage distribution require a comparatively large volume in the interior of the switch housing of the hybrid switch, so that it requires a comparatively large and consequently also expensive switch housing.

PRESENTATION OF THE INVENTION

The invention, as characterized in the independent claims, solves the problem of providing a hybrid circuit breaker, which is inexpensive to create and has a high availability.

In this hybrid power switch, the first steep rise of the recurring voltage is substantially maintained by the second quenching chamber formed as a vacuum switching chamber. The reconsolidation of the extinguishing path of the first quenching chamber may therefore take place here relatively slowly, which means that the blowing of the first quenching chamber may be much less intense than conventional circuit breakers. For the provision of the pressurized gas required for the blowing of the arc so much less energy must be expended.

The advantages achieved by the invention can be seen in the fact that the hybrid circuit breaker can be equipped with the same power switching capacity with a much weaker and thus cheaper drive. Furthermore, the pressures occurring in this hybrid power switch in the first quenching chamber are much lower than in conventional circuit breakers, so that the insulating tubes and the other pressurized parts can be designed for lower loads, whereby a more economical design of the hybrid circuit breaker is possible. Furthermore, it has the advantageous effect that the flow velocity of the gas cooling the arc in the first quenching chamber can be in the subsonic range because of the considerably less intensive blowing required here, since thereby the amount of pressurized gas to be provided for the blowing can be kept comparatively small. Another advantage is the fact that the Abbrandkontakte the second quenching chamber, which is designed here as a vacuum interrupter chamber, because of the shorter duration of the current load when switching off and because of avoiding repeated Durchzündens the rise of the recurring voltage have a longer life, which is advantageous improved operational availability of the hybrid circuit breaker result.

The hybrid circuit breaker is provided with at least two in series, operated by a common drive or separate drives, filled with different extinguishing media extinguishing chambers, the extinguishing and insulating medium of the first arcing chamber surrounding the second arcing chamber. There are provided means which ensure a technically meaningful voltage distribution over the two extinguishing chambers during the turn-off. Furthermore, means are provided, which at the switch-off a time advance of the movement of the first quenching chamber with respect to the Ensure movement of the second chamber. When switching on, the second quenching chamber always closes in front of the first quenching chamber. As a quenching and insulating medium of the first quenching chamber, a gas or a gas mixture is used. As a second quenching chamber, at least one vacuum switching chamber is provided. However, other switching principles can also be used for the second quenching chamber.

The further embodiments of the invention are the subject of the dependent claims.

The invention, its development and the advantages that can be achieved with it are explained in more detail below with reference to the drawing, which represents only one possible embodiment.

BRIEF DESCRIPTION OF THE DRAWING

• Fig. 1 eine Ausführungsform eines stark vereinfacht dargestellten Hybridleistungsschalters im eingeschalteten Zustand, bei welcher der Lichtbogen in der ersten Löschkammer durch in einer Kolben-Zylinder-Anordnung komprimiertes Gas beblasen wird,
• Fig. 2 diese Ausführungsform des stark vereinfacht dargestellten Hybridleistungsschalters im ausgeschalteten Zustand, und
• Fig. 3 einen stark vereinfachten Schnitt durch eine Ausführungsform der in dem Hybridleistungsschalter eingesetzten Vakuumschaltkammer.

Show it:

• 1 shows an embodiment of a hybrid circuit breaker shown in greatly simplified form in the switched-on state, in which the arc in the first arcing chamber is blown by compressed gas in a piston-cylinder arrangement,
• Fig. 2 shows this embodiment of the hybrid circuit breaker shown greatly simplified in the off state, and
• Fig. 3 is a greatly simplified section through an embodiment of the vacuum switching chamber used in the hybrid circuit breaker.

In all figures the same elements are provided with the same reference numerals. All elements not required for the immediate understanding of the invention are not shown or described.

WAYS FOR CARRYING OUT THE INVENTION

FIG. 1 shows a greatly simplified first embodiment of a hybrid power switch 1 in the switched-on state. This hybrid circuit breaker 1 has two series-connected extinguishing chambers 2 and 3, which here along a common longitudinal axis 4 extends mounted and are arranged concentrically to this. It is quite possible to arrange the extinguishing chambers 2 and 3 in different embodiments of this hybrid circuit breaker 1 on different, mutually angled longitudinal axes. It is even conceivable that in the variant with angled longitudinal axes, these longitudinal axes are not only in one plane or in two mutually parallel planes, but also that these planes intersect at a constructively meaningful angle.

The hybrid circuit breaker 1 is driven by a drive, not shown, via a drive linkage 5, which consists of electrically insulating material. As a drive, a conventional power storage drive can be provided. But it is also possible to use an electronically controllable DC drive without the interposition of a force accumulator. This embodiment is considered to be particularly economical and also makes it possible to adapt the contact speeds of the hybrid circuit breaker 1 to the particular special operational requirements with simple means. Between the two extinguishing chambers 2 and 3, a transmission 6 is arranged, which the movements of the two extinguishing chambers 2 and 3 linked together and the motion sequences technically meaningful to each other.

The drive linkage 5 is protected against environmental influences by a support insulator 7 supporting the quenching chambers 2 and 3 of the hybrid circuit breaker 1. The support insulator 7 is the earth pressure-tight connected to the drive, not shown, the extinguishing chamber side, it is provided with a metallic flange 8, which is bolted to a first metal flange 9. About the connection flange 9, the drive side of the quenching chamber 2 is connected to the electrical network. With the connection flange 9, a first end flange 10 of a quenching chamber housing 11 is further screwed. The quenching chamber housing 11 is cylindrical, pressure-tight and electrically insulating, it extends along the longitudinal axis 4 and surrounds the two extinguishing chambers 2 and 3 and the gear 6. The quenching chamber housing 11 has on the first end flange 10 opposite side a second metallic end flange 12 , which is bolted to a second metallic connecting flange 13. About the connection flange 13, the drive remote from the side of the quenching chamber 3 is connected to the electrical network. Between the end flange 12 and the connecting flange 13, a metallic support plate 14 is held.

The connecting flange 9 is rigidly and electrically conductively connected to the cylindrically shaped metallic support tube 15, which is arranged concentrically to the longitudinal axis 4. The support tube 15 has openings, not shown, which serve the gas exchange between the interior of the support tube 15 and the rest of the extinguishing chamber volume. The drive-side inner part of the support tube 15 serves as a guide for a guide member 16 which is connected to the drive linkage 5 is and this is supported against the support tube 15. The guide member 16 is formed so that it limits the stroke h1 of the drive linkage 5, when the hybrid circuit breaker 1 is in the off position.

The drive linkage 5 is connected at the front end to a metallic contact tube 17, which represents a first movable power contact of the first extinguishing chamber 2. The shaft of the contact tube 17 has openings, not shown, which serve for gas exchange between the interior of the contact tube 17 and the interior of the support tube 15. The contact tube 17 is provided on the side facing away from the drive with resilient Abbrandfingern 18, which are arranged tulip-shaped. The Abbrandfinger 18 enclose and contact a metallic Abbrandstift 19. The Abbrandstift 19 is axially extending in the center of the quenching chamber 2 and arranged axially movable. The Abbrandstift 19 always moves opposite to the direction of movement of the contact tube 17. The Abbrandstift 19 represents the second movable power contact of the first quenching chamber 2.

The support tube 15 has on the side facing away from the drive on a taper 20 and a guide portion 21 which guides the contact tube 17. The guide part 21 is provided inside with spiral contacts, not shown, which allow the proper passage of current from the support tube 15 to the contact tube 17. On the taper 20 slides outside a metallic nozzle holder 22, which is provided on the drive side with sliding contacts 23, which allow a proper flow passage from the support tube 15 to the nozzle holder 22.

The nozzle holder 22 encloses a compression volume 24. The compression volume 24 is closed on the drive side by a check valve 25, which through the Guide section 21 is held. The check valve 25 has a valve disc 26 which prevents the discharge of the compressed gas into the common extinguishing chamber volume 27 for the two extinguishing chambers 2 and 3 at an overpressure in the compression volume 24. On the opposite side of the cylindrically shaped compression volume 24, a further, held in the nozzle holder 22 check valve 28 is provided, the valve disc 29 at an overpressure in the compression volume 24 allows the exit of the compressed gas from this compression volume 24.

In the nozzle holder 22, an insulating nozzle 30 is held on the side facing away from the drive. The insulating nozzle 30 is arranged concentrically around the burn-off pin 19. The contact tube 17, the nozzle holder 22 and the insulating nozzle 30 form a one-piece assembly. The nozzle throat is located immediately in front of the Abbrandfingern 18 and the insulating nozzle 30 opens in the Abbrandfingern 18 opposite direction. The nozzle holder 22 has on the outside a designed as a contact point thickening 31. On this thickening 31 are in the on state of the quenching chamber 2 sliding contacts 32. These sliding contacts 32 are connected to a cylindrically shaped metallic housing 33, which is held by a stationary mounted metallic guide member 34. In a central bore of the guide member 34 sliding contacts, not shown, are provided which connect the guide member 34 with the Abbrandstift 19 electrically conductive. From the guide part 34, the current path, as a line of action 35 indicates, continues via a connection part 44 to the movable contact 36 of the second extinguishing chamber 3.

On the side facing away from the drive of the insulating nozzle 30, an electrically insulating retaining plate 37 is rigidly secured thereto. However, the retaining plate 37 can also from a Be made of metal, if the dielectric conditions in this area allow this. In this retaining washer 37, a rack 38 is screwed, which extends parallel to the longitudinal axis 4 and which actuates the transmission 6. The rack 38 is engaged with two gears 39 and 40, it is pressed by a support roller 41 against these gears 39 and 40. In the shaft of the guided through the guide member 34 Abbrandstifts 19 is provided with a toothed groove, into which the gear 39 engages. A further support roller 42 presses the shaft of Abbrandstifts 19 against the gear 39. The gear 40 is actuated via a lever 43 coupled to it movable the second arcing chamber 3. The lever 43 is coupled to the connecting part 44, which is electrically conductive with the movable contact 36th the second quenching chamber 3 is connected.

The second quenching chamber 3 is shown here schematically as a vacuum interrupter chamber. It is for example possible to realize the switching point of this quenching chamber 3 by means of other switching principles. The quenching chamber 3 is surrounded by the insulating medium, which fills the common quenching chamber volume 27. The quenching chamber 3 has a fixed contact 45, which is electrically conductively connected to the support plate 14. The support plate 14 serves to fix the quenching chamber 3. The quenching chamber 3 has an insulating housing 46 which separates the interior of the quenching chamber 3 from the quenching chamber volume 27 in a pressure-tight manner. Here is the. Isoliergehäuse 46 shown partially cut.

The wall of the insulating housing 46 is provided with a resistance pad 47. This, for the necessary when switching off the control of the distribution of the recurring voltage across the two extinguishing chambers 2 and 3 provided resistance coating 47 may be applied to the inner or on the outer surface of the insulating housing 46. Through this cheap, very space-saving design of the resistor pad 47, the dimensions of the second quenching chamber 3 can be kept advantageously small. The ohmic resistance of the resistor pad 47 is here in the range between 10 kΩ and 500 kΩ, as the resistance of 100 kΩ has proven to be particularly favorable.

3 shows an embodiment of the second quenching chamber 3, which is designed here as a vacuum interrupter chamber, in a greatly simplified representation. This vacuum interrupter chamber is provided with a cylindrically shaped, electrically conductive screen 49 which keeps switching residues from the insulating housing 46 and from the resistance covering 47. The screen 49 is connected by means of an electrically conductive bridge 50 with the potential center of the resistor pad 47, it is defined when turned off at this potential. The contacting of the bridge 50 with the resistance covering 47 takes place by means of a conductive coating applied to the resistance coating 47. However, embodiments without this bridge 50 are also conceivable. The resistance pad 47 may be applied in a strip-shaped manner on the inner or outer surface of the insulating housing 46, but its entire surface may also be coated with the resistance pad 47.

The resistance coating 47 here has a matrix of epoxy resin into which, evenly distributed, soot and spherical glass particles are embedded. The soot serves as an electrical conductor, with the amount of the mixed soot, the resistance value of the resistive lining 47 is set. The spherical glass particles serve as a filler; They have the task of matching the coefficient of expansion of the resistor pad 47 to that of the insulating housing 46, in order to prevent the resistance pad 47 from becoming detached from the insulating housing 46 when thermal expansions occur. Of the Resistance surface 47 can be prefabricated and then glued into the insulating housing 46 or glued on the outside; but it can also be applied as a paste on the respective surface of the insulating housing 46 and then cured, where it adheres very well to the material of the insulating housing 46. The insulating housing 46 used here is made of a ceramic material, but other insulating materials are also conceivable. During the curing process, the insulating housing 46 is then heated.

The casting resin used for the matrix of the resist pad 47 may be derived from any one of the groups of the anhydride-cured epoxy resins, the unsaturated polyester resins, the acrylic resins, and the polyurethane resins. But it is also possible to use an electrically conductive silicone resin with appropriately adjusted conductivity as a resistance pad 47. The spherical glass particles serving as filler have a diameter of 1 .mu.m to 50 .mu.m, with a good average distribution in the range between 10 .mu.m and 30 .mu.m. Advantageously, spherical glass particles are used, which are already coated with an adhesion promoter, since then the connection between the Giessharzmatrix and the spherical glass particles is particularly intimate, so that a very homogeneous resistance coating 47 is formed. In combination with or even without the spherical glass particles, other mineral and other inorganic fillers can be used.

The common extinguishing chamber volume 27 is filled with an electrically insulating, electronegative gas or gas mixture, which serves both as an extinguishing medium for the first extinguishing chamber 2 and as an insulating medium. The filling pressure is here in the range of 3 bar to 22 bar, preferably 9 bar filling pressure are provided. As extinguishing and insulating medium pure SF ₆ gas or a mixture of N ₂ gas used with SF ₆ gas. But it is also possible here to use a mixture of compressed air or from N ₂ gas and other electronegative gases. Gas mixtures with a proportion of 5% to 50% SF ₆ gas have proven particularly suitable.

When switched on, the hybrid power switch 1 carries the current via the following, designated as rated current path current path: flange 9, support tube 15, nozzle holder 22, housing 33, guide member 34, line of action 35, connector 44, movable contact 36, fixed contact 45, support plate 14 and flange 13. However, it is also possible, in particular when the hybrid power switch 1 must be designed for comparatively high rated currents, to provide a separate nominal current path suitable for high nominal currents also parallel to the second extinguishing chamber 3.

When the hybrid power switch 1 receives a turn-off command, the drive, not shown, moves the contact tube 17 and with this the insulating nozzle 30 to the left. At the same time with this movement, the Abbrandstift 19 driven by the rack 38 via the gear 39 moves in the opposite direction to the right, while the housing 33 and the guide member 34 remain stationary. As soon as the thickening 31 of the nozzle holder 22 has separated from the sliding contacts 32 of the housing 33, the above-mentioned nominal current path is interrupted and the current to be disconnected now commutates to the internal power flow path. The power flow path leads through the following switch parts: connecting flange 9, support tube 15, guide section 21, contact tube 17, Abbrandstift 19, guide member 34, line of action 35, connector 44, movable contact 36, fixed contact 45, support plate 14 and flange 13th

The contact tube 17 and with this the insulating nozzle 30 moves after breaking the Nennstrombahn further to the left, and the Abbrandstift 19 moves at the same speed in the opposite direction on. In the course of this movement, the contact separation in the power flow path then takes place. This contact separation has the consequence that forms an arc between the Abbrandfingern 18 and the tip of Abbrandstifts 19 in a dedicated arc chamber 48.

Dabei ist t_{Libo min} die für die mit Gas beblasene Löschkammer 2 minimal mögliche Lichtbogenzeit in ms, die durch die Netzdaten des jeweiligen Einsatzorts des Hybridleistungsschalters 1 und die Eigenschaften des Hybridleistungsschalters 1, beispielsweise durch dessen Eigenzeit, bestimmt wird. Die Zeit t₁ liegt im Bereich von 2 ms bis 4 ms. Diese zeitliche Verzögerung T_v wird zwangsweise durch das Getriebe 6 erzeugt. Die zweite Löschkammer 3 hat auch einen wesentlich kleineren Hub h2 als die Löschkammer 2, wie aus der Figur 2 ersichtlich ist.Until this time, the second quenching chamber 3 is usually closed. It opens only after a time delay T _v , which is defined by the following relationship: $${\mathrm{T}}_{\mathrm{v}}=({\mathrm{t}}_{\mathrm{Libo\; min}}-{\mathrm{t}}_1)\mathrm{ms}\mathrm{,}$$

In this case, t _{Libo min is} the minimum possible arc time in ms for the gas-blown quenching chamber 2, which is determined by the grid data of the particular site of use of the hybrid power switch 1 and the properties of the hybrid power switch 1, for example by its own time. The time t ₁ is in the range of 2 ms to 4 ms. This time delay T _v is forcibly generated by the transmission 6. The second quenching chamber 3 also has a substantially smaller stroke h2 than the quenching chamber 2, as can be seen in FIG.

During the switch-off movement of the first quenching chamber 2, the gas or gas mixture in the compression volume 24 is compressed, the check valve 25 prevents the escape of the compressed gas on the side facing away from the insulating nozzle 30 of the compression volume 24 in the common quenching chamber volume 27. Through the check valve 28 already flows comparatively small amount of the compressed gas in the arc chamber 48, if the prevailing pressure conditions allow. The diameter of the throat of the insulating nozzle 30, the diameter of the Abbrandstifts 19, at the beginning of the disconnection still a substantial part this Düsenengnisses and also the outflow cross section through the Abbrandfinger 18 closes, and the inner diameter of the contact tube 17 are coordinated so that during the blowing of the arc always sufficient gas or mixture of non-ionized and ionized gas is discharged from the arc chamber 48, so There can only build a significantly lower compared to conventional circuit breakers gas pressure there. The height of this gas pressure is set so that the outflow velocity from the arc chamber 48 is usually in the range below the sound limit. As a result of these comparatively small pressures in the arc chamber 48, the pressure build-up in the compression volume 24 can also be kept comparatively small, so that only a comparatively small drive energy is required for the compression. Compared to conventional circuit breakers can here at the hybrid circuit breaker 1, due to the lower gas pressures when switching off, advantageously a weaker and thus cheaper drive can be used.

Immediately after the contact separation in the power flow path, the burn-off pin 19 releases a greater part of the cross-section of the throat of the insulating nozzle 30 as an outflow cross-section. With comparatively small turn-off currents, the blowing of the arc burning in the arc chamber 48 begins already during the contact separation. The extinguishing and insulating medium always flows during this blowing at a flow rate which is in the range below the speed of sound. When switching off larger currents, as can occur, for example, when shutting off short circuits in the network, the arc heats the arc chamber 48 and the gas present in him so intense that the pressure in this room is slightly higher than the pressure in the compression volume 24th In this case, the check valve 28 prevents the heated and pressurized gas flows into the compression volume 24 and can be stored there. The heated and pressurized gas instead flows on the one hand through the interior of the contact tube 17 and on the other hand through the insulating nozzle 30 into the common quenching chamber volume 27. The blowing of the arc is in this case only when the intensity of the arc and thus the pressure in the arc chamber 48 has decayed so far is that the check valve 28 can open, that is, the pressure in the compression volume 24 is then higher than the pressure in the arc chamber 48. The extinguishing and insulating medium flows in this case during the blowing of the arc at a flow velocity in the range below the speed of sound lies.

In this embodiment of the hybrid power switch 1, the arc chamber 48 of the first quenching chamber 2 is designed so that a very small dead volume is present, so that no appreciable storage of pressurized gas generated by the arc itself can take place, and consequently no significant support of the blowing of the arc self-generated pressurized gas takes place, because only so it is possible to ensure a flow velocity in the subsonic area in the blowing of the arc.

When the extinguishing chambers 2 and 3 have extinguished the arc, between the Abbrandfingern 18 and the Abbrandstift 19 of the quenching chamber 2, or between the movable contact 36 and the fixed contact 45 of the quenching chamber 3, in each case a part of the recurring voltage. The switching path of the vacuum interrupter solidifies immediately after extinguishing always faster than the switching path of a gas switch, so that the vacuum interrupter chamber will take over the greater part of this voltage at the beginning of the steep rise of the recurring voltage. The distribution of the recurring voltage on two series-connected extinguishing chambers is normally determined by the self-capacitances of the two extinguishing chambers. Here, however, represents the comparatively high-resistance of the resistor pad 47, which is arranged parallel to the second quenching chamber 3, exactly defined sure that the division of the recurrent voltage to the two quenching chambers 2 and 3 takes place so that initially the greater proportion of the recurrent voltage applied to the second quenching chamber 3 , Only in the further course of the turn-off then the first quenching chamber 2 takes over the majority of the recurring voltage, which then acts on the hybrid circuit breaker 1 total. In the off state of the hybrid circuit breaker 1, the first quenching chamber 2 holds the majority of the applied voltage. In the design of this resistive voltage control, care is taken that in the second quenching chamber 3 no reignifications can occur in the rise of the recurring voltage.

In the figure 2, the hybrid circuit breaker 1 is shown in the off state. When switching on the hybrid power switch 1 always closes first, the second quenching chamber 3, and without current. This time lead is ensured by the transmission 6. Only after the second quenching chamber 3 is closed, move the two movable contacts of the power flow path of the first quenching chamber 2 towards each other. When the appropriate pre-ignition distance is reached, an inrush arc forms and closes the circuit. The two moving contacts of the power flow path of the quenching chamber 2 continue to move towards each other until they contact each other. Only then, the nominal current path is closed and takes over the further current flow through the quenching chamber 2. The two moving contacts of the power flow path of the quenching chamber 2 move a little further until they have finally reached the definitive closed position.

It proves to be particularly advantageous in this hybrid power switch 1 that the second quenching chamber 3 de-energized turns on and is therefore subject to no contact erosion and no contact bonding due to welding of superheated contact surfaces when switching. The contacts 36 and 45, assuming normal operating conditions, need not be replaced during the lifetime of the hybrid power switch 1, which advantageously simplifies the operational maintenance of the hybrid power switch 1 and advantageously increases its operational availability.

As the first extinguishing chamber 2, in addition to the described, provided with a compression volume 24 for the generation of the necessary for the blowing of the arc pressurized gas embodiment, further embodiments may be used, such as: a quenching chamber with a separate storage volume for the storage of gas generated by arc support, which cooperates with the compression volume, or a quenching chamber with an only partially compressible storage volume for storing the generated by arc support gas component, or a quenching chamber with an only partially compressible blowing volume, in which the pressurized gas is generated completely without arc support.

In each of these embodiments of the hybrid power switch 1, the second quenching chamber 3 is also opened when switched off with respect to the first quenching chamber 2 delayed in time and closed at the time of switching on, as already described. Further, in each of the embodiments described herein, the drive forces can be additionally assisted in turning off by means of a differential piston. By this measure, the need for mechanical drive energy can be further reduced in a simple manner and the drive can be further reduced in price.

In the above-described embodiments of the hybrid circuit breaker 1, it has been found to be particularly advantageous that, depending on the SF ₆ content in the gas filling the quenching chamber 2, compared to conventional circuit breakers by a factor of 5 to 15 lower extinguishing pressure in the quenching chamber 2 is required , The drive and the other components can therefore be designed for lower force and pressure loads, which advantageously reduces the cost of the hybrid circuit breaker 1.

NAME LIST

1

Hybrid circuit breaker

2.3

extinguishing chamber

4

longitudinal axis

5

drive linkage

6

transmission

7

support insulator

8th

flange

9

flange

10

end flange

11

Extinguishing chamber housing

12

end flange

13

flange

14

support plate

15

support tube

16

guide part

17

contact tube

18

consumable fingers

19

consumable

20

rejuvenation

21

guiding part

22

nozzle holder

23

sliding contacts

24

compression volume

25

check valve

26

valve disc

27

Arcing chamber volume

28

check valve

29

valve disc

30

insulating

31

thickening

32

sliding contacts

33

casing

34

guide part

35

line of action

36

moving contact

37

retaining washer

38

rack

39.40

gear

41.42

supporting role

43

lever

44

connector

45

fixed contact

46

insulating

47

resistance coating

48

Arcing area

49

umbrella

50

bridge

Claims (14)

1. Hybrid circuit breaker (1) having at least two series-connected arcing chambers (2, 3) which are operated by a common drive or by separate drives and are filled with different arc extinguishing media, where the arc extinguishing and insulating medium in a first arcing chamber (2) surrounds a second arcing chamber (3) in an insulating manner, where means are provided which ensure a sensible voltage distribution between the first (2) and the second arcing chamber (3) in the course of a switching process, and where a pressurized gas or a gas mixture is used as the arc extinguishing medium and insulating medium in the first arcing chamber (2), while at least one vacuum switching chamber having an insulating housing (46) is provided as the second arcing chamber (3), characterized

   - in that means are provided which always ensure that the disconnection movement of the first arcing chamber (2) leads the disconnection movement of the second arcing chamber (3) during a disconnection process, and that the connection movement of the second arcing chamber (3) always leads the connection movement of the first arcing chamber (2) during a connection process,

   - in that the second arcing chamber (3) is permanently bridged by a non-reactive resistor, and

   - in that the non-reactive resistor is in the form of a resistance coating (47) which is applied to the inner wall or the outer wall of the insulating housing (46) of the second arcing chamber (3).
2. Hybrid circuit breaker according to Claim 1, characterized

   - in that the value of the non-reactive resistor is in the range between 10 and 500 kΩ, but is preferably 100 kΩ.
3. Hybrid circuit breaker according to Claim 1 or 2, characterized

   - in that the resistance coating (47) is introduced into, or applied externally to, the insulating housing (46) in the form of a paste which can be painted on and has a curable casting-resin matrix, and is connected to this insulating housing (46) during the curing process.
4. Hybrid circuit breaker according to Claim 1 or 2, characterized

   - in that the resistance coating (47) is introduced or applied as a prefabricated part having a cured casting-resin matrix, and is connected to the insulating housing (46).
5. Hybrid circuit breaker according to one of Claims 1 to 4, characterized

   - in that the coefficient of expansion of the resistance coating (47) is matched to that of the insulating housing (46) by means of spherical glass particles which are used as a filler, where these glass particles have a diameter of from 1 µm to 50 µm, and have good average distribution in the region between 10 µm and 30 µm.
6. Hybrid circuit breaker according to Claim 5, characterized

   - in that the spherical glass particles are coated with an adhesion promoter.
7. Hybrid circuit breaker according to one of Claims 1 to 6, characterized

   - in that the conductivity of the resistance coating (47) is achieved by adding conductive particles, preferably carbon-black particles.
8. Hybrid circuit breaker according to one of Claims 3 to 7, characterized

   - in that the casting resin used for the matrix of the resistance coating (47) originates from one of the groups of anhydride-cured epoxy resins, unsaturated polyester resins, acryl resins or polyurethane resins.
9. Hybrid circuit breaker according to Claim 1, characterized

   - in that the first arcing chamber (2) has a power current path and a rated current path in parallel with it, and

   - in that the second arcing chamber (3) has no separate rated current path.
10. Hybrid circuit breaker according to Claim 1, characterized

    - in that both the first (2) and the second arcing chamber (3) have a power current path and a rated current path connected in parallel with it.
11. Hybrid circuit breaker according to Claim 1, characterized

    - in that pure SF₆ gas or a mixture composed of N₂ gas and SF₆ gas, or else a mixture composed of compressed air with other electrically negative gases, is used as the arc-extinguishing and insulating medium.
12. Hybrid circuit breaker according to Claim 11, characterized

    - in that a gas mixture in which the proportion of SF₆ gas is from 5% to 50% is preferably used.
13. Hybrid circuit breaker according to Claim 12, characterized

    - in that the filling pressure of the first arcing chamber (2) is in the range from 3 bar to 22 bar, but is preferably approximately 9 bar.
14. Hybrid circuit breaker according to Claim 1, characterized

    - in that the time lead T_v of the disconnection movement of the first arcing chamber (2) with respect to the second arcing chamber (3) during disconnection is defined by the following relationship: $${\mathrm{T}}_{\mathrm{v}}=\left({\mathrm{t}}_{\mathrm{Libo}\mathrm{\hspace{0.17em}}\min }-{\mathrm{t}}_1\right)\mathrm{m}\mathrm{s}$$

    

    where t_{Libo min} is the minimum possible arcing time for the first arcing chamber (2), and t₁ is a time in the range from 2 ms to 4 ms.

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