DE1490919A1 - Arrangement for capacitive tapping of a voltage in an electrical device - Google Patents

Description

w ₊ · ν. U'90919

Westinghouse

Electric Corporation May 22, 1962

East Pittsburgh

WE Caae 33 505

62/8016

Arrangement for capacitive tapping of a voltage in an electrical device

For this application, the priority is derived from the corresponding American patent application Ser.lTo.114 145

claimed from 1.6.1961.

The invention is generally concerned with an arrangement for capacitive tapping of a voltage in an electrical circuit Device for high voltage. In particular, it relates to a tap arrangement that connects the high-voltage lines to such devices includes.

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When operating high-voltage equipment for relatively high Voltages, for example on the order of 46 kV and above, it is often desirable to have a way of with which small amounts of energy can be drawn from the high-voltage lines. The commonly used potential taps provide a relatively low voltage that is substantially proportional to the phase-to-earth voltage and is in phase with this. This output becomes common used to energize synchroscopes, voltmeters and voltage dependent relays. The well-known potential taps therefore form an effective means of supplying a voltage for operating relays, gauges and synchronizers to obtain.

In accordance with the foregoing, it is a general object of the invention to provide an improved tapping arrangement a voltage for electrical devices to create relatively high voltages, with the voltage-dependent monitoring devices and the like can be operated.

A more specific object of the invention is to provide an improved tap assembly that is compact in size, is easy to install in the device and is economical to manufacture and can be operated effectively and accurately.

Another object of the invention is to provide an improved voltage tap for a circuit breaker which

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can easily be attached to a socket on the housing that carries the bushing.

Another object of the invention is to provide an improved voltage tap that consists of a cylinder with a undefined potential exists. The cylinder is inside the support socket of a grounded, gas-filled Circuit breaker housing attached, in such a way that it allows the removal or installation of the associated gas-filled implementation not bother.

In patent application W 28 821 VIIId / 21c = PLA 60/8045 the use of a Potentxal cylinder in the interior of a gas-filled bushing is indicated. A disadvantage of the arrangement of the cylinder inside the bushing consists of the following: If a customer originally bought the cylinder and the associated one Voltage tap arrangement does not want and then later for some reason changes his view and such an arrangement wants to have installed, it is necessary to completely dismantle the gas-filled bushing before the potential cylinder can be used.

A further object of the invention is therefore to provide an exterior with a preferably gas-filled bushing arranged metal cylinder. Such a cylinder can easily be used in electrical devices according to the original Installation can be installed without incurring additional costs. The additional workload is also low.

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In short, the invention provides a metal cylinder created, which is mounted in an isolated manner in the socket of the earthed housing, which is an electrical device, e.g. a gas-filled Circuit breaker, includes. The cylinder lies in the radial direction outside the implementation, di-e into the Housing extends. Therefore, a small part of the conductor-earth voltage is capacitively absorbed by the metal cylinder. With With the help of a voltage connection, which can be guided through the housing socket and the electrical connection Establishes contact with the cylinder, it is possible to transfer this small part of the conductor-earth voltage to an external one to lead voltage-insensitive device in order to operate the same.

Further objects and advantages of the invention will emerge from the following description in conjunction with the drawings. It shows

Figure 1 a · ■. . · 'Tcilansicht a gasge filled high-voltage circuit breaker in which the He realized the invention, partly in section,

FIG. 2 is, on an enlarged scale, a partial view of the metal cylinder according to FIG. 1 and the associated support device.

Figure 3 is an enlarged section of the voltage terminal abutting the cylinder, making contact .

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FIG. 4 is an enlarged partial view of the voltage connection according to FIG. 3, which is against the metal cylinder is present.

In the drawing, in particular in Figure 1, 1 denotes as a whole a gas-filled circuit breaker, which is for a Voltage and rated power of 138 kV, 10 000 MVA is suitable. A detailed description of how the Circuit breaker 1 can be found in patent application V / 27 052 VIIIb / 21c = PLA 60/8001.

To understand the present invention, however, it is only necessary to know that the power post-switch 1 is a grounded Has metal housing 2, which consists of an elongated grounded central part 3, a detachable end cap 4 and an upright there is a cylindrical connecting piece 5 for fastening the bushings 6, as shown in FIG.

The switch 1 has two bushings per se. However, only one is shown in the figure. The vertically extending bushings 6 have axially extending bushing bolts 7. They carry a substantially horizontally arranged elongated interruption device 9. The interruption device includes a high-pressure container 10 and a number of extinguishing units connected in series, which are not shown. Each erase unit having two separable switch-piece assemblies, and a composed of insulating material nozzle ^v

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chamber, which allows the flow of a gas under high pressure, e.g. of sulfur hexafluoride gas (SFg) "at a pressure of 17.5 at. The flow of pressurized gas is triggered by the action of a suitable blow valve, not shown, which is assigned to the high-pressure container 10 and is actuated simultaneously with the movement of the shell piece s.

In the patent application W 28 821 VIIId / 21c = PLA 60/8045 with the title "implementation" shows a implementation that has a potential cylinder in its interior near the having grounded flange. The bushing has a bare bushing bolt that passes axially through the bushing and is sufficiently insulated from the earthed flange with the aid of sulfur hexafluoride gas (SFg). That SFg gas is assigned to the interior of the circuit breaker housing taken.

As mentioned above, there are times when power companies change their minds and after the initial installation want to have a potential cylinder built into the switch. This is the case with the construction according to the aforementioned Patent application only possible in that the entire bushing is dismantled so that the potential cylinder located inside: can be installed. This requires more effort in terms of implementation.

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It is a clear advantage of the invention that the aforesaid

Dismantling is avoided by keeping the metal cylinder outside the implementation is arranged in the connector 5 of the housing 2, as shown in FIG.

In FIG. 2 of the drawing it can be seen that the metallic potential cylinder 11 is opposite to the fastening flange ring 12 which forms the upper end of the connecting piece 5 is isolated. A number of insulating struts 14 with machine screws are used as insulation 15 and 16 attached. The four insulating struts are next to the upper edge of Hades cylinder 11 and the lower one Surface 17 of the flange ring 12 attached. So that the lower one Part of the cylinder 11 with the nozzle 5 can not make any contact, are preferably made of insulating rivets 18 arranged at a distance from one another in the area of the lower edge 11b of the metallic potential cylinder 11. The cylinder 11 is made from an elongated rectangular strip of a suitable one Material, e.g. aluminum, which is rolled into a cylinder and joined along the abutting edges. <is welded.

The bare bolt 7 of the 'bushing 6 is held by zv / ei Forzellan Union covers 6a, 6b. A grounded flange ring 6c provided between the porcelain housings is spaced around the circumference spaced mounting holes is with bolts 6d screwed to your flange ring 12. The free space between the bare bushing bolt 7 and the inner surface of the

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Porcelain covers 6a, 6b is coated with a gaseous dielectric, e.g. SFg, filled. This construction essentially agrees with that of the implementation according to the aforementioned application W 28 821 VIIId / 21c = PLA 60/8045 match.

In order to pass the tapped voltage through the connection piece 5 of the housing, a connection arrangement 19 is provided which ' is shown in FIG. As can be seen from Figures 3 and 4, an insulating material bushing 20 is provided through "which a conductive bolt 21 is led through in a gas-tight manner. With, the insulating material part of the bushing 20 is a with a Flange provided collar 20a soldered hermetically tight (see FIG. 4). Adjacent the inner end of the bolt 21 a butt contact 23 is provided. This works like a telescope with a compression spring 24 made of conductive material, as can be clearly seen in FIG. The compression spring 24 in turn strikes at 25 against the outer wall 26 of the cylinder

> The metallic flange part 20b of the implementation 20 is at the assembly with a seal 30 and a support plate provided with holes 31 fastened together in that a Number of bolts 32 are screwed into a support block 33 which is welded at 34 to the connecting piece 5 of the housing 2. A Guide tube 38 'made of insulating material is inside a bore of the block 31 is arranged. It has two radio. · Functions to fulfill: 1. It must lead the compression spring 24 and 2 ". The current path from the potential cylinder 11 to earth opposite-

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isolate over block 31. A cable 41 of the device 42 to be supplied with voltage is connected by means of suitable connecting nuts (Figure 1) connected.

From the above description it can be seen that the cylinder 11 according to the invention has very little space within the nozzle 5 of the housing 2 occupies. It can be easily installed and does not interfere with the removal of the bushing 6.

The cylinder 11 capacitively absorbs an electrical charge, " which depends on the voltage of the bushing 6. The voltage and current of this electrical charge are used to power the device 42 to operate for measurement purposes.

In the arrangement shown, the bushing flange 6c of the implementation 6 can be designed with a low height, as FIG. 1 shows. This allows the implementation 6 in their Construction height can be reduced. This in turn leads to a reduction in costs and better electrical properties | and reduces the overall height of the circuit breaker, which is advantageous for transporting the assembled breaker. Of the The diameter of the bushing can also be made smaller, since there is no space for the inside of the bushing Potential cylinder is required. The metal cylinder is easily accessible in the housing socket 5 in the event of a repair should be required. For a repair of the Metalla / linder Implementation 6, on the other hand, would be an expansion of the

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Implementation may be required. This is a time consuming costly work.

Another advantage of the metal cylinder inside the nozzle 5 is that the cylinder can be omitted for jobs where it is not wanted and still later can be built in at the place of installation if it should be required at a later date. For bushings with built-in cylinders on the other hand, because of the complicated manufacturing process, "all bushings were provided with potential cylinders, irrelevant whether these were used or not. This procedure made it more expensive.

In a 138 kV three-phase circuit breaker, cited as an example and not by way of limitation, the phase-to-ground voltage is about 80 kV and the voltage of the metal cylinder 11 in the event that it is released, about 3000 V against earth. When using a voltage-dependent device, on the other hand, the voltage drops to a small fraction of this Value, for example to 5 to 6 V, if a capacitor of 0.015yUF is constantly between the terminal pin 21 and earth lies.

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Claims (6)

Claims 1. Arrangement- · sum capacitive tapping of a voltage an electrical device for high voltage with a grounded housing in which a bushing is inserted, in particular in the case of a power switch with sulfur hexafluoride and / or selenium hexafluoride all extinguishing agents, characterized in that a metal cylinder surrounding the bolt of the bushing separated from the bushing inside the earthed housing *, is attached isolated. and has a terminal at which a voltage is tapped off with respect to the earthed housing 2. Arrangement according to claim 1, characterized in that the connection is insulated out through the wall of the housing to the outside is. 3. Arrangement according to claim 1, characterized in that a spring part for connection, which presses against the outside of the metal, the cylinder. 4. Arrangement according to claim 3, characterized in that the Spring is arranged in an insulating tube, which is through the Wall of the earthed housing leads. 5 · Arrangement according to claim 1 for a device, the housing of a cylinder is formed, the implementation of a - 11 - 909831/0411 U90919 WE-Case 33 505 cylindrical nozzle is carried, which is attached to the circumference of the cylinder, characterized in that the metal cylinder is arranged in the nozzle. 6. Arrangement according to claim 5 with a free end of the The connecting piece's detachable metal flange, characterized in that that the metal cylinder is attached to the metal flange. - 1 2 - BATH ORIGINAL 309831/04 1