DE2834772A1 - HIGH VOLTAGE SELF-SWITCHING WITH SELF-INFLATION - Google Patents

Description

High-voltage circuit breaker with self-blowing

The invention relates to a high-voltage circuit breaker with self-blowing

- from one arranged inside a tight housing, with an insulating gas of high dielectric strength Dielectric strength filled separation chamber,

- from a self-blowing device, which contains a piston-cylinder unit compressing the gas, which includes a pumping chamber and a flowing of the blowing gas as well as the extinguishing of a during the opening of the switch between separable contacts arc drawn in a separating gap, which is cut out in the interior of a separating chamber coaxial with said contacts able to

- from one in the lower zone of the housing for the accumulation of the at low ambient temperatures liquefied insulating gas located main collecting tank and

- From pumping means, which from the separation of the contacts to the collecting container to return the liquefied gas into the separation space

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work together, with the high temperature of the arc causing the evaporation of the liquefied Gas.

In automatic switches with Selbstbeblasung results at temperatures which are below the liquefaction temperature of the insulating gas contained in the housing, the problem that the efficiency of cutting off can not always be ensured due to the lower density of the gas present in the separation gap _e In normal use of the circuit breaker in cold areas, the contacts are in the closed position and the continuous current flowing in the separating chamber causes the gas in the switch to be heated by the Joule effect. A disconnection after a long switch-on time will generally be less unfavorable than if the switch was open for a longer period of time and then suddenly ^{subjected to an II} closed "-" open "cycle Switch in a period of great cold, the gas condenses on the cold walls of the separation chamber and is collected in the liquid state in the collecting container in the lower area of the chamber.

In a known circuit breaker of the type mentioned, with a phase of pre-compression of the isolating gas,

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the pumping means for the liquefied gas consist of one special blow pump for self-blowing device, whereby the supply of the liquefied gas to the extinguishing area is ensured after the automatic switch has been opened will. As a result, a certain amount of liquid is liquefied during the pre-compression phase after the contacts have been separated Gas blown; the pump is formed by a movable auxiliary cylinder, which is connected to the movable contact positively connected and on a fixed auxiliary piston Is slidably guided, which is located in the lower region of the collecting container. The cylinder is through a pipe small inside diameter, provided with openings on the head and inside the movable contact arranged; he represents the injection of an axial jet Liquefied gas in the extinguishing chamber as soon as the movable contact is moved into the "open" position. After the pre-compression phase, the separation of the contacts creates the electric arc and it blows the Self-blowing device a radial gas jet into the extinguishing chamber, causing the axial and radial Gas rays extinguish the arc at the end of a certain displacement path of the moving contact. In the meantime the different density of the gas of the two separate jets is not particularly favorable for one quick extinguishing of the electric arc; the generation of the axial gas jet also makes a special blow pump necessary"

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In other known devices, an electric heater, which is controlled as a function of the outside temperature, heats Auxiliary heating the housing to prevent its temperature from falling to prevent under the liquefaction limit of the insulating gas.

Accordingly, it is the object of the invention to avoid one to indicate the known disadvantages of further developed and simplified self-blowing switches, in particular without an additional pump for the liquefied gas and without an additional heating device and can also be used reliably in areas where it is very cold.

The solution is in a high-voltage circuit breaker of the type described in that the pump means also a connecting line between the collecting container and the pump chamber of the self-blowing device in this way involve moving the switch to the closed position of the contacts to an automatic suction of the liquefied by the pressure reduction caused in the pump chamber Gas can be brought about into the pump chamber while increasing the density of the gas.

So there are in an advantageous manner the mentioned

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Additional measures have become dispensable because the
Anyway necessary pumping means a connecting line between the collecting tank for the liquefied
Extinguishing gas and the pumping chamber (ie the volume which can be changed by the fixed piston in the movable cylinder). This causes the actuation of the
Self-switch in the direction of "closing" the contacts taking place pressure reduction an automatic suction of the liquefied gas into the pump chamber, which here leads to an increase in the density of the insulating gas during the
Phase of closing the switch leads.

The liquefied gas is injected into the pump chamber at the same time as the refilling of the insulating gas that enters the space inside the housing from closing of the switch is sucked in. It is advantageous from the pressure drop in the pump chamber of the self-blowing device Made use of both the liquefied gas in the main collection tank and at the same time sucking in the insulating gas of the housing. The arrangement according to the invention eliminates the need for a special injection pump; they are replaced by a simple line between the main collecting tank and the pump chamber. Cheap is also the suction of the liquefied gas exclusively during the closing phase of the switch and the cessation of the

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Gas delivery at the beginning of the opening of the switch during the Pre-compression of the gas “During the separation of the contacts the self-blowing device blows a single jet of compressed gas into the separation space and thus extinguishes the electric arc very quickly "

According to one embodiment, the connecting line has throttling means.

According to a further embodiment, the connection line contains a lower end that dips into the main liquefied gas sump, further upper end, which penetrates the fixed part of the self-inflating device, e.g. the piston or the cylinder, so as to form an inlet opening in the pump chamber.

According to one embodiment of the last-mentioned measure, the inlet opening is a check valve opposite the pump chamber educated. This valve is in the inlet position when there is negative pressure in the pump chamber when the switch is closed, but in the shut-off position in order to maintain the overpressure of the gas from opening the switch.

Further details of the subject matter of the invention and the advantages obtained can be found in the following description an embodiment and from the accompanying schematic drawing; in this show:

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1 shows an automatic switch with self-inflation including pumping means according to the invention in an intermediate position during the closing of the switch, shown as an axial section and

FIG. 2 shows the device analogous to FIG. 1, but with the moving parts in the position during the opening of the switch _{or the like}

As the drawing shows, the single-pole high-voltage switch includes a separating chamber 10 within a tight housing 12 made of an insulating building material which is filled under pressure _{with an insulating gas of high dielectric strength, in particular sulfur hexafluoride SF g.} An electrically conductive cover 14 closes the housing at the top, serves as a power supply and carries the hollow fixed contact 16, which in the closed position of the switch interacts with the hollow movable contact 18 by inserting ₀ The movable contact 18, which extends in the direction of the axis XX ' is held slidably in the chamber 10, traverses the bottom 20 made of conductive building material in the lower region of the housing 12 on the side opposite the cover 14 and continues in an insulated actuating rod 22 which is connected to an actuating device (not shown) _β the actuating rod extends axially through a hollow support insulator 24 of the same pole.

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A self-inflating device 26 consists of a cylinder 28 carried by the movable contact 18 and cooperates with a fixed piston 30 in such a way that a pump chamber 32 for compressing the insulating gas is formed. The compression causes the gas to flow out into the separating intermediate space 34 (extinguishing path) when the Position of the contacts 16,18 causes. The movable cylinder 28 is provided with a blowing nozzle 36 which has a converging / diverging inner contour. In the closed position, the nozzle coaxially envelops the contacts. The converging area communicates with openings 38 which are arranged in the cylinder 28 in such a way that the compressed blowing gas in the pump chamber 32 is blown directed into the separating intermediate space 34 or into the extinguishing path. In the closed position, the neck of the nozzle surrounds the fixed contact 16 of the switch with little play. There are also contact fingers 40 disposed inside an electrically conductive tube 42 for supporting the fixed piston 30, in conductive connection with the movable contact 18. The current then runs in the tube 42 to the floor 20, which is a feed-through terminal 44 has «

The actual switch of the type described above is known per se, which is why it is not necessary to provide further details to describe. In the closed position, the current enters through the terminal on the conductive cover 14 and flows through the

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Contacts 16,18 and the contact fingers 40, the electrical conductive tube 42 and floor 20 for bushing glue 44. The fixed contact 16 penetrates the end, which is nozzle-shaped is formed, of the movable contact 18 a little. The converging part of the nozzle 36 is through the Fixed contact 16 closed. The opening of the switch is initiated by sliding down the operating rod 22, which takes the movable contact 18 with it. In a first movement phase, the fixed contact 16 still remains in the blowing nozzle 36 and fitted in the movable contact 18, whereby any escape of the blowing gas is prevented. The latter is pre-compressed by the movable cylinder 28 when this is the movement of the movable contact 18 follows during its downward slide. At the end of this first pre-compression phase, the moving contact separates 18 from the fixed contact 16, an arc being drawn inside the blowing nozzle 36, but at the same time for the blowing gas an outlet opening is created. In the second phase it causes continued sliding movement of the moveable Contact 18, the flow of the pre-compressed gas stream into the separating space 34 and thus the extinguishing of the arc .

According to the invention, the bottom 20 to the housing 12 and the tube 42 which carries the stationary piston 30, form one Main collecting tank 48 for receiving the sulfur hexafluoride

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SFg, which is in the liquid state at low ambient temperatures. Said parts coaxially surround the hollow movable contact 18. The pumping means also include at least one connecting line 50 including a throttling means, the lower end of the line dipping into the main collecting container 48 for the liquefied gas. The upper end of the line passes through the fixed piston 30 and forms an inlet opening 52 in the pump chamber 32. This inlet opening 52 is operatively connected to a valve 54 which cooperates with the pump chamber 32. The valve can alternately assume an open position in which inflow is possible due to the negative pressure prevailing in the pump chamber 32 while the switch is closing, and a closed position in which the compression of the SF _{g is} ensured during the opening of the switch. The stationary piston 30 has an annular cavity at the top, whereby an additional container 56 is formed which serves _{to collect the SF g liquefied in the pump chamber 32 o} The stationary piston 30, the main collecting container 48, the additional container 56, the electrical The conductive tube 42 and the base 20 are formed in one piece. The connecting line 50 extends parallel to the ^{sliding axis XX 1} to the movable contact 18. Further openings 58, which belong to the valves 60, allow the inflow of insulating gas, which after the switch is closed is sucked out of the housing 12.

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The mode of operation of the switch according to the invention is as follows: During the closing process shown in Fig. 1, the sliding of the actuating rod 22 causes after above an enlargement of the pumping chamber 32 “This results there is a pressure reduction which causes the valves 54 and 60 to assume the "open" position, whereby automatic suction of the liquefied gas accumulated in the collecting container 48 and also of the inside of the housing 12 located insulating gas takes place. This results in an increase in the density of the gas opening the switch.

After opening the switch, a preliminary sliding movement in advance of the movable contact 18 in the first movement phase after the opening 52 and the openings 58 are closed when the valves 54 are in the closed position and the gas in the pump chamber 32 is pre-compressed the suction of liquefied gas stopped _o During the second movement phase (Fig. 2), the continued sliding movement of the actuating rod 22 separates the movable contact 18 from the fixed contact 16, whereby an electric arc is drawn between the two contacts, the high temperature of which immediately evaporates the liquid SF _g ensures that the gas jet compressed by the self-blowing device 26 and blown into the separating space 34 inside the blowing nozzle 36 is contained _B

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The high density of the SF _fi before the pre-compression phase is particularly advantageous with regard to quick extinguishing of the arc while it is occurring, in particular in the case of switches that are used in areas with a harsh climate.

The subject matter of the invention does not only include what has been described above and shown in the drawing embodiment, but also extends to the field of all mechanical and electrical equivalences, such as, B " those in which the self-blowing device 26 to the contacts 16, 18 without the preliminary pre-compression phase of the insulating gas.

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Claims (1)

Γ "\: _ ι! _-, _ C" Τλ ^^^ λ · ■ Γ Please state my reference! D _iP l, lng.E.Tergau _{+ h} .l. p, * ;. 28/45 (78399) Patent attorney Nuremberg, August 8th 1978 Merlin Gerin, 38000 Grenoble (France) Patent claims (1.) Consisting of high-voltage circuit breakers with self-blowing - from one arranged inside a tight housing, with an insulating gas of high dielectric strength Dielectric strength filled separation chamber, - from a self-blowing device, which contains a piston-cylinder unit compressing the gas, which includes a pumping chamber and a flowing of the blowing gas as well as the extinguishing of a during the opening of the switch between separable contacts arc drawn in a separating gap, which is cut out in the interior of a separating chamber coaxial with said contacts able to - from one in the lower zone of the housing for the accumulation of the at low ambient temperatures liquefied insulating gas located main collecting tank and 909809 / 08U Hefnersplatz 3 Telephone (0911) Telex Telegrams Bayer. Vereinsbank Stadtsparkasse Postscheckkonto Nürnberg 11 204081-83 06/22327 '■' "Patwetzel" Nbg. 6311696 Nbg. 1.528.354 Nuremberg 11151-853 ORIGINAL INSPECTED - From pumping means, which from the separation of the contacts to the collecting container to return the liquefied gas cooperate in the separation space, the high temperature of the Arc causes the liquefied gas to evaporate, characterized in that the pumping means also include a connecting line (50) between the collecting container (48) and the pumping chamber (32) of the self-blowing device (26) in such a way that from moving the switch in the closed position of the contacts through the in the pumping chamber (32) caused pressure reduction an automatic suction of the liquefied gas into the pump chamber (32) with an increase in the density of the gas can be brought about " 2 _e circuit breaker according to claim 1, characterized in that throttling means are built into the connecting line (50). 3. Circuit breaker according to claim 1, characterized in that the connecting line (50) includes a lower end which is arranged immersed in the collecting container (48) for the liquefied gas, that an upper end of the line (50) is a portion of the fixed element for self- 909809 / 08U blowing device, ζ.Β _β penetrates the piston (30) or the cylinder, and that thereby an inlet opening (52) is formed in the pump chamber (32) _e 4. Circuit breaker according to claim 3, characterized in that said inlet opening (52) with a non-return valve (54) arranged in the pump chamber (32) cooperates and that the non-return valve (54) is designed such that the When the pressure in the pump chamber (32) is reduced, the valve is in the "open" position while the switch is being closed, but assumes a "closed" position securing the pressure build-up when the switch is opened. 5. Circuit breaker according to one or more of the claims 1 to 4, characterized in that an additional, trough-shaped container (56) is incorporated in the bottom of the pumping chamber (32) to recover the liquefied gas. 6 _β circuit breaker according to one or more of Claims 1 to 5, characterized in that the switch is designed for the use of sulfur hexafluoride (SF,.) As an insulating gas. 7. Automatic switch according to one or more of claims 1 to 6, characterized in that the fixed part (z, B _e piston 30) of the self-blowing device (26) 9Q98G9 / 08U as well as the main collecting container (48) and the additional container (56) form a one-piece component for the liquefied gas and that this component is slidable in the separation chamber (10) guided movable hollow contact (18) wrapped coaxially. 8. Circuit breaker according to claim 8 / characterized / that the connecting line (50) which is arranged between the one-piece component and the inner wall of the housing (12) / extends parallel to the sliding axis XX ^{1 of} the movable contact (18). 9. High-voltage automatic switch with self-blowing, especially for use in harsh climates, which switch in a sealed housing containing SF ^ has a separating chamber and a movable contact that can be separated from a fixed contact and the self-blowing device, characterized in that a piston-cylinder The device for the SF _g includes a pumping chamber (32) such that when the contacts are in a separate position, a jet of compressed gas can be blown into the separating space (34) so that a collecting container (48) for recovering the SF _{g which is liquefied at low temperatures} is present that further a connection line (50) between the pump chamber (32) and the collecting container (48) is arranged so that through 903809/0814 the pressure drop caused in the pump chamber (32) when the movable contact (18) closes, an automatic one The liquefied gas can be sucked into the pump chamber (32) while increasing the density of the gas. 10. Circuit breaker according to one or more of claims 1 to 9, characterized / that the interior of the housing (12) can be connected to the pump chamber (32) through openings (58) provided with valves (60) in its wall parts. 909809 / 08U