EP1383142B1 - Electric pluggable device, in particular an over-voltage arrester - Google Patents

Abstract

The fastening is molded-into the casing (1) containing the active section (6) with freedom of axial movement. Before formation of the plug-in connection, it (6) is compression spring- (18) loaded against the casing. An Independent claim is included for the corresponding method of manufacture.

Description

TECHNICAL AREA

The invention is based on a plug-in electrical apparatus, in particular a surge arrester, according to the preamble of Claim 1. This apparatus has an axially symmetrical trained Housing with a running in the direction of plug housing axis and on Means for securing the apparatus housing to a housing of a High-voltage system. Furthermore, the electrical apparatus has a axially symmetric active part on with an axially guided circuit containing a plug contact, a ground connection and an interposed nonlinear resistance element. The active part also contains a axially symmetrical insulating body, which forms an insulating cone and the non-linear resistance element and an electrical connection to Plug contact surrounds. Under high voltage nominal voltages are greater here 1 kV and typically up to 72 kV.

When installing the apparatus in the high voltage system, the active part in a Plug socket of the high voltage system and the apparatus housing with the Fasteners fixed to the system housing. When plugging is the Circuit of the apparatus with a conductor of the high voltage system electrically connected and at the same time the insulating cone and a Isoliergegenkonus the system pressed against each other gap-free. It will be like that Heavy duty connector with a high quality dielectric insulation achieved. The electrical apparatus is generally a surge arrester and then has a non-linear, voltage-dependent resistance element, such as on the basis of a varistor and / or a spark gap. He can also as Earthing switch be executed and then indicates as non-linear Resistor element on a switching point.

The invention also relates to a high voltage system with such electrical apparatus and a method by which such a facility is manufactured can be.

STATE OF THE ART

With the generic term, the invention takes a prior art of electrical apparatus, as described in EP 1 083 579 A2. An in This patent publication described, pluggable surge arrester contains a bottle-shaped executed, aligned along an axis Metal housing with a largely axially symmetric formed active part. The active part has an axially guided circuit with a varistor and with two power connections. The circuit is electrically powered by an insulating body fixed in the metal housing. Both power connections of the circuit are led out of the housing. One of the two power connections is on High voltage, the other at ground potential feasible. This surge arrester Can be installed by plugging into a high voltage system. in this connection become the plug contact and a mating contact of the system put together and so becomes an electrically conductive connection between the Circuit and a high voltage applied to the head of the plant produced. A supported on the housing via a compression spring and as a flange executed fastener is then bolted to the system housing. About the biased when screwing compression spring the arrester with defined force and held in a resilient manner to the plant.

PRESENTATION OF THE INVENTION

The invention as defined in the claims solves the problem, a specify electrical apparatus of the type mentioned, which in particular simple manner can be installed in the high voltage system.

In the apparatus according to the invention, the fastening means in the Device housing molded and is the active part in the apparatus housing in Slidably mounted axial direction and before the formation of a connector held with respect to the apparatus housing with biasing force. The Apparatus housing can be practically without effort on the High voltage system to be attached. An electrically conductive connection between the circuit of the inventive apparatus and a with High voltage loadable conductor of the plant can be done by simple means be achieved by reducing the bias. Here, the active part of the Apparatus moved in the axial direction until the plug contact with a Gegensteckkontakt the system forms a plug connection and the insulating cone the active part with a predetermined force without gaps on a Isoliergegenkonus the plant is present. The support force can be dimensioned so very accurate and Accordingly, be sized so that leading to partial discharges column be avoided at the interface of the insulating cone. Because the support force can be kept slightly constant and also inside the apparatus housing acts, a constant contact pressure is guaranteed and will also be safe prevents the pressure from the outside, such as by loading the Apparatus housing with mechanical force, is changed.

To partial discharges between the surface of the insulator and the To effectively reduce equipment housing, it is expedient to use the insulating body to provide an electrically conductive layer. It is kept free of this layer the exposed during operation of the plant high electric field strengths Insulating cone. The remote from the plug contact end of the insulating cone is with Advantage undercut formed and carries an inwardly guided, rounded portion of the electrically conductive layer. Through these measures is a strong relief of the operation of the plant dielectrically highly loaded End of the insulating cone reached.

On the dielectric behavior of the apparatus or the system it affects favorable if the provided in the apparatus circuit non-linear Resistance element plug contact side and the same in the apparatus circuit provided electrically conductive connection of this resistor element to Plug contact are rounded. Another improvement of dielectric strength is achieved when the insulating body at least in high electric field strengths exposed plug contact side area rounded is executed.

To facilitate the installation of the electrical apparatus in the system, it is recommended it is to form an opening in a lateral surface of the apparatus housing. Through this opening, the position of a mark of the insulating body be observed during assembly. Based on this information, the Fitter easily check if the active part of the apparatus is already sufficiently far was moved. At the same time this opening serves to relieve the pressure of Apparatus in the event of arcing faults and partial discharges on the active part. There Such unwanted discharge processes particularly effective in the field of high electric field strengths, it is recommended that the opening opposite one Position the insulating body, the plug-in end of the nonlinear resistor element. Appropriately, are at Training the apparatus housing as a cylinder at least two against each other in Provided circumferential direction of the cylinder staggered openings provided so the mark not only from one direction, but one through the Displacement angle predetermined angular range can be observed.

The required preload force is in an apparatus with a s.einem earthed end of the active part and fastened by a bottom of the Apparatus housing outwardly guided ground connection preferably by a prestressed compression spring which reaches between the groundable end of Active part and the bottom of the apparatus housing is arranged. To the Preload is easy and precise to change, is in the from the Apparatus housing guided end of the ground terminal formed a thread for receiving a clamping nut. At this thread concludes with an advantage the device housing guided, thread-free section, which is the storage one between the clamping nut and the bottom of the apparatus housing providable locking sleeve is used. Will this sleeve after mounting the Removed apparatus, so when pressing the clamping nut no more power be transferred to the active part of the apparatus, so that an improper Disassembly or maintenance of the apparatus is excluded by unauthorized persons. The Clamping nut can be used in training as a lock nut, the Connect ground connection to a grounding conductor.

In an easy to implement, robust embodiment of the Apparatus according to the invention is an axial in the bottom of the apparatus housing aligned and the grounding comprehensive sleeve formed with a the guide of the compression spring serving lateral surface.

To different dimensions of the fasteners of apparatus housing and to compensate for plant housing, it is recommended when assembling the Apparatus to use an adapter flange, which between a flange the fastening means of the electrical apparatus and a counter flange of the Plant housing is provided and the dimension of a flange on the Dimensions of the other flange reduced.

Advantageously, the apparatus housing and the system housing are electrically conductive educated. After assembly of the apparatus is then the apparatus housing without an additional connection via the flanges and the system housing grounded and protection against contact is ensured.

DESCRIPTION OF THE DRAWINGS

Fig.1

eine Aufsicht auf einen längs einer Achse geführten Schnitt durch eine als Überspannungsableiter ausgebildete Ausführungsform des steckbaren elektrischen Apparats nach der Erfindung,

Fig.2

den geschnitten dargestellten Überspannungsableiter gemäss Fig.1 beim Einbau in eine Hochspannungsanlage während dreier zeitlich aufeinanderfolgender Phasen a), b) und c), und

Fig.3

eine Seitenansicht des (nicht geschnitten dargestellten) Überspannungsableiters gemäss Fig.1 während der zeitlich aufeinanderfolgenden Phasen a), b) und c) beim Einbau gemäss Fig.2.

A preferred embodiment of the invention and the advantages that can be achieved thereby are explained in more detail below with reference to drawings. Hereby shows:

Fig.1

a plan view of a guided along an axis section through a designed as a surge arrester embodiment of the pluggable electrical apparatus according to the invention,

Fig.2

1 when installed in a high-voltage system during three temporally successive phases a), b) and c), and the surge arrester according to FIG

Figure 3

a side view of the (not shown cut) surge arrester according to Figure 1 during the successive phases a), b) and c) during installation according to Fig.2.

WAYS FOR CARRYING OUT THE INVENTION

In all figures, like reference numerals designate like-acting parts. Of the shown in Fig. 1 surge arrester A has as protection against contact and as Protection against external influences a predominantly cylindrical, electrical conductive apparatus housing 1, which in particular made of metal, such as Aluminum, an electrically conductive polymeric material, for example a polyethylene filled with conductive carbon black, or one electrically conductive conductive jacket provided polymeric material, such as polyethylene. The housing 1 includes a jacket tube 2. At the lower end of the tube is a Floor 3 is set, while at the upper end a fastening means is formed, which is designed as a radially outwardly extended flange 5. in the Apparatus housing 1, an active part 6 is arranged. The inner diameter of the Apparatus housing has over the active part excess. The active part can Therefore, be moved along the cylinder axis 7 of the housing 1. The active part includes an axially guided circuit with a plug contact 8, a Ground terminal 9 and a non-linear resistance element 10. On High voltage potential feasible end of the resistive element 10 is over a conductor pin 11 connected to the plug contact 8. The other end of the Element 10 is connected to the bolt-shaped ground connection 9. The non-linear resistance element 10 may be as in the prior art according to EP 1 083 579 A2 is to be formed and then has one or several cylindrical varistor elements on non-linear Resistance material, for example based on metal oxide, in particular of ZnO. The plug contact 8 is mounted on a field-controlling disc 12, which when connecting the surge arrester A to one in FIGS. 2 and 3 shown high-voltage system H, for example, a metal-encapsulated, Gas-insulated switchgear for a nominal voltage of, for example, 42 kV, as Stop to a counter stop of the system H is used.

The non-linear resistance element 10 and the conductor pin 11 are of a axially symmetrical insulating body 13 made of an elastic insulating material, such as preferably silicone, surrounded. The insulating body 13 runs at its upper end in a coaxial with the upper portion of the conductor pin 11 of the circuit surrounding insulating cone 14. A remote from the plug contact 8 end of Insulating cone 14 runs in an inwardly guided, rounded undercut 15 off. The surface of the insulating body 13 is up to the conical surface of the Insulating cone 14 with a potential-controlling, electrically conductive layer 16, such as a conductive polymer or a metal coated. About a Active part 6 at the grounding connection 9 downwards closing contact disk 17 the electrically conductive layer 16 is connected to ground potential.

Between the contact disk 17 and the bottom 3 of the apparatus housing 1 is a prestressed compression spring 18 is arranged. This feather is on one Lateral surface of a molded into the bottom 3 of the apparatus housing 1, axially aligned bearing sleeve 19 out. In the sleeve 19, the ground terminal 9 Slidably mounted in the axial direction. In a from the apparatus housing 1 led end of the ground terminal 9, a thread 20 is formed on which is designed as a locknut clamping nut 21 is screwed. At the thread 20 closes a likewise guided out of the apparatus housing 1, unthreaded section 22 for storage of a between the clamping nut 21st and the bottom 3 of the apparatus housing 3 provided securing sleeve 23rd

From Fig.2 it can be seen that when installed in a high voltage system H of Surge arrester A (process phase a)) initially in the direction of a not designated arrow is guided vertically upwards. The upper end of the active part 6 is characterized by an undefined opening of an electrically conductive, grounded housing 30 of the high voltage system H in a connection socket 31st with a shielded, tulip-shaped mating contact 32 and with a Isoliergegenkonus 33 pushed.

Once the flange 5 on a suitable mating flange of the plant housing 30 is applied (process phase b)), both flanges by means of not designated screws connected and so is the Apparatus housing 1 rigidly attached to the system housing 30. If the flange 5 and the mating flange of the system H have different dimensions is - how shown in Figure 2 - between the two flanges an adapter flange 34th provided.

Subsequently, the prestressed compression spring 18 by means of the clamping nut 21st relaxed. The clamping nut supports itself with its upper side Unterlegescheiben on the downwardly facing end of the locking sleeve 23rd from. The active part is under the effect of turning the nut relaxing spring 18 in the connector 31 is inserted until the disc 12 abuts the mating plug contact 32 (process phase c)). Plug contact 8 and Gegensteckkontakt 32 now form a connector and connect the Circuit of surge arrester with one with high voltage can be acted upon conductor 35 of the system H. The compression spring 18 is only so far relaxed that the remaining spring force is still sufficient to the cones 14, 33 so strongly pressed together that no air gap remains in between. It is then a sufficiently high dielectric strength of the in High voltage system H built-in surge arrester A ensured. Since the spring 18 is constantly acting with the same force and also inside the Apparatus housing 1 is arranged, a constant contact force is ensured and is also prevented with certainty that the contact pressure from the outside, about by loading the apparatus housing 1 with mechanical force, is changed.

To improve the dielectric strength also carries the electrically conductive Layer 16, through which partial discharges between the surface of Insulating body 13 and the apparatus housing 1 and in inhomogeneities of Insulator 13 can be avoided. By training of the plug contact. 8 opposite end of the insulating cone 14 as inwardly guided and rounded Undercut 15 and providing a portion of the electrically conductive Layer 16 on the surface of this undercut 15 is the electrical Field in the dielectrically critical triple area of apparatus or plant housing, Insulating cone 14 or Isoliergegenkonus 33 and air homogenized. Further Measures to improve the dielectric properties of the Surge arrester A and the high-voltage system H are also in that the non-linear resistance element 10 and / or the insulating body 13 at least plug contact side are rounded.

As can be seen from Figure 3, during assembly of the Surge arrester the position of the active part 6 in the socket with Help a mounted on the active part or the layer 16 mark 36th be checked. For this purpose, in the lateral surface of the apparatus housing 1 a narrow, guided mainly in the axial direction opening 37 formed. During the phases a) and b), the position of the marker 36 changes in the Opening 37 not, since the active part relative to the apparatus housing 1 at prestressed compression spring is not moved. Only in phase c) shifts when relaxing the spring, the mark 36 relative to the apparatus housing. 1 upwards and takes after complete insertion of the active part in the Connect the socket from the phase c) apparent position.

The opening 37 is positioned opposite a portion of the insulating body 13 which the plug contact end of the non-linear resistive element 10 includes. This is advantageous insofar as the opening 37 at the same time the pressure relief of Surge arrester A in the event of arcing faults and partial discharges can serve on the active part 6. Because such unwanted discharge processes are particularly effective in the field of high electric field strengths, is the opening at the plug contact end of the nonlinear resistive element 10th positioned.

Conveniently, two are offset from each other in the circumferential direction arranged openings provided. It is thus ensured that the location of the Marker 36 not just from one direction, but one through the Displacement angle predetermined angular range can be observed. By Provide more than two suitably distributed over the entire circumference Openings can be observed from virtually any direction.

After installation of the surge arrester A, the clamping nut 21 of Drawn thread 20 and the locking sleeve 23 is removed and unauthorized Access secured. The clamping nut 21 is again on the thread 20th screwed. Since it is designed as a lock nut, it also serves the Fixation of a ground conductor 38 (Fig.2). The circuit of the Surge arrester is now on the one hand to the in the high voltage system H led high voltage and on the other hand connected to earth. The Apparatus housing 1 is above the adapter flange 34 and the plant housing 30th grounded. An unauthorized movement of the active part 6 after installation of the Surge arrester A in the high-voltage system H is thereby avoided that withdrawn locking sleeve, the clamping nut 21 only until thread-free section 22 can be rotated, and thus without locking sleeve 23 can cause no shift of the active part.

LIST OF REFERENCE NUMBERS

1

apparatus housing

2

casing pipe

3

ground

5

flange

6

active part

7

cylinder axis

8th

plug contact

9

varistor

10

nonlinear resistance element

11

Head bolt

12

disc

13

insulator

14

insulating cone

15

undercut

16

electrically conductive layer

17

contact disc

18

compression spring

19

bearing sleeve

20

thread

21

locknut

22

thread-free section

23

securing sleeve

30

conditioning housing

31

socket

32

Mating plug contact

33

Isoliergegenkonus

34

adapter flange

35

conductor

36

mark

37

opening

38

grounding conductor

A

Surge arresters

H

High-voltage system

Claims (17)

1. Pluggable electrical apparatus, in particular a surge arrester (A), with an axially symmetrically formed housing (1) with a housing axis (7) running in the plugging direction,
   a means for fastening the apparatus housing (1) on a housing (30) of a high-voltage installation (H), and with
   an axially symmetrical active part (6) with an axially routed circuit, including a plug-in contact (8), an earthing terminal (9) and a non-linear resistance element (10) connected in between, and with
   an axially symmetrical insulator (13), which forms an insulating cone (14) and surrounds the non-linear resistance element (10) and an electrical connection (11) with respect to the plug-in contact (8),
   characterized in that the fastening means is formed into the apparatus housing (1), and
   in that the active part (6) is mounted displaceably in the axial direction in the apparatus housing (1) and held with a prestressing force with respect to the apparatus housing (1) before a plug-in connection is formed.
2. Apparatus according to Claim 1, characterized in that the insulator (13) is provided with an electrically conductive layer (16).
3. Apparatus according to Claim 2, characterized in that an end of the insulating cone (14) remote from the plug-in contact (8) is configured as an undercut (15) and bears an inwardly disposed, rounded portion of the electrically conductive layer (16).
4. Apparatus according to one of Claims 1 to 3, characterized in that the non-linear resistance element (10) is given a rounded form on the plug-in contact side.
5. Apparatus according to Claim 4, characterized in that the insulator (13) is given a rounded configuration, at least on the plug-in contact side.
6. Apparatus according to one of Claims 1 to 5, characterized in that an opening (37) is formed into a lateral surface of the apparatus housing (1).
7. Apparatus according to Claim 6, characterized in that the opening (37) is positioned opposite a region of the insulator (13) which comprises the end of the non-linear resistance element (10) on the plug-in contact side.
8. Apparatus according to either of Claims 6 and 7, characterized in that, when the apparatus housing (1) is formed as a cylinder, at least two openings arranged offset with respect to each other in the circumferential direction of the cylinder are provided.
9. Apparatus according to one of Claims 1 to 8, in which the earthing terminal (9) is fastened to an earthable end of the active part (6) and led through a base (3) of the apparatus housing (1), characterized in that a prestressed compression spring (18) is arranged between the earthable end of the active part (6) and the base (3) of the apparatus housing (3).
10. Apparatus according to Claim 9, in which a thread (20) is formed into an end of the earthing terminal (9) led out from the apparatus housing (1), characterized in that the thread (20) serves for receiving a clamping nut (21), and in that the earthing terminal (9) has a thread-free portion (22) which is led out from the apparatus housing (1) and serves for the mounting of a securing sleeve (23) which can be provided between the clamping nut (21) and the base (3) of the apparatus housing (1).
11. Apparatus according to either of Claims 9 and 10, characterized in that a bearing sleeve (19) which is axially aligned and encloses the earthing terminal (9) is formed into the base (3) of the apparatus housing (1), with a lateral surface serving for guiding the compression spring (18).
12. High-voltage installation (H) with the electrical apparatus (A) according to one of Claims 1 to 11, with a fastening means for the electrical apparatus (A) provided on a housing (31) of the installation (H) and with a mating plug-in contact (32) and a mating insulating cone (33), in which installation (H), after plugging together, the fastening means of the installation housing (31) and the fastening means of the electrical apparatus (1) are rigidly connected and the insulating cone (14) and the mating insulating cone (33) are pressed against each other without a gap.
13. Installation according to Claim 12, characterized in that an adapter flange (34) is arranged between a fastening means of the electrical apparatus (A), configured as a flange (5), and a mating flange of the installation housing (30).
14. Installation according to either of Claims 12 and 13, characterized in that the apparatus housing (1) and the installation housing (30) are given an electrically conductive form, and in that the apparatus housing (1) is earthed via the fastening means and the installation housing (31).
15. Method for producing the high-voltage installation (H) according to one of Claims 12 to 14, characterized in that the fastening means of the electrical apparatus (A) is fixed on the fastening means of the high-voltage installation (H), and in that, after that, the active part (6) of the electrical apparatus (A) is led into the installation housing (30), with the prestressing force being reduced, with an electrical plug-in connection of the plug-in contact (8) and mating plug-in contact (32) being formed and with gap-free pressing of the insulating cone (14) and mating insulating cone (33) being formed.
16. Method according to Claim 15, characterized in that, during or after the reduction of the prestressing force, the position of a marking (36) of the active part (6) is checked in an opening (37) of the apparatus housing (1).
17. Method according to either of Claims 15 and 16, characterized in that the prestressing force is changed by turning a clamping nut (21) supported on a securing sleeve (23), and in that the securing sleeve (33) is removed after the plug-in connection has been formed and the cones (14, 33) pressed.

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