WO2008119575A1

WO2008119575A1 - Assembly housing arrangement for the pulsed current resistant integration of at least one pre-made electrical breakdown fuse

Info

Publication number: WO2008119575A1
Application number: PCT/EP2008/051164
Authority: WO
Inventors: Georg Wittmann; Josef Birkl; Jens Ehrler
Original assignee: Dehn + Söhne Gmbh + Co. Kg
Priority date: 2007-04-03
Filing date: 2008-01-31
Publication date: 2008-10-09
Also published as: EP1999828A1; EP1999828B1

Abstract

The invention relates to an assembly housing arrangement for the pulsed current resistant integration of at least one pre-made electrical breakdown fuse, in particular based on a spark gap. According to the invention, a base body made of a pressurizable insulating material is provided, which on at least one side has an opening for receiving an insert in the form of the electrical breakdown fuse, wherein the opening has a contour which positionally fixes the insert, and starting at the opening a pressure equalization chamber extends within the base body. On opposite sides of the base body, contact plates are located which are mechanically connected to the base body, wherein the opening extends as far as the contact plates and is closed off by said plates. Furthermore, the insert located in the opening comes into electrical contact with the contact plates. The outer sides of the contact plates have contact pieces as external contacts, oriented in the direction of the longitudinal axis of the whole arrangement.

Description

Mounting housing arrangement for the pulse current fixed integration of at least one prefabricated voltage arrester

description

The invention relates to a mounting housing arrangement for pulse-current-proof integration of at least one prefabricated voltage breakdown fuse, in particular spark gap base, with or without integrated gas discharge arrester according to the preamble of patent claim 1.

Spark gap inserts as voltage breakdown protection for the protection of einschienigen track circuits are known for example from DE 199 21 772 C2.

Such a spark gap insert as a voltage breakdown fuse has an air gap, formed from at least two arranged in an insulating housing, opposite metallic disk-shaped electrodes. The disc-shaped electrodes are based on the insulating housing over and can come into contact with corresponding fittings or connection plates.

Between the electrodes, partially covering them, there is an insulator layer or insulator disk, with the air flashover point forming within the housing between the electrodes.

In one embodiment variant of a voltage breakdown fuse, at least one of the disk-shaped electrodes has a recess or depression, wherein a gas discharge conductor, contacting the respective electrode surfaces, is inserted into the cavity formed by the recess or recess, so that there is an electrical parallel connection of air spark gap and gas discharge gap graded response results.

In this case, the air gap as a voltage protection against line frequency line voltage by permanent short circuiting and functionally separates the gas discharge path designed as a voltage protection against overvoltage due to lightning and line follower currents.

Voltage breakdown fuses have the task of grounding non-earth-grounded plant components in the area of rail-bound traffic engineering when a certain permissible voltage is exceeded in a short-circuit-proof manner.

Such voltage breakdown fuses are used for protection functions in the return line of DC and AC tracks, plant components in the catenary and pantograph area are permanently connected to the return line when the response voltage is exceeded, so that triggers the protection in the substation due to the flowing power frequency short-circuit or fault current.

Cause of exceeding the allowable voltage z. B. mains-frequency overvoltages due to catenary short circuits and trolley earth faults, caused by catenary rupture or so-called earth wipers. Also transient overvoltages, caused by direct lightning strikes, near lightning strikes and distant lightning strikes and concomitant propagating overvoltages in the rail system as so-called line-bound traveling waves can lead to an exceeding of the permissible voltages.

In order to prevent the occurrence of dangerous overvoltages between insulated tracks of electrical tracks and grounded parts of the system, the aforementioned voltage breakdown fuses are used.

In the case of a catenary short circuit or ground fault then occurs a secure equipotential bonding by high current resistant welding of the electrodes.

A preferred application for voltage breakdown is the so-called "open rail manure" conductive components in the overhead line and Current collector area according to DIN EN 50122-1 for DC and AC railways.

In the case of alternating current railways, direct railway traffic is the preferred method of protection for the safety of persons and for the protection of the installation. If rails may not be grounded directly, for example for reasons of track vacancy

Voltage breakdown safeguards when their response voltage is exceeded, a current-carrying connection to the return line forth.

In direct current railways, the use of voltage breakdown fuses prevents direct connections of grounded system components to the rails. This avoids stray current corrosion on the rails and adjacent systems.

Previously known voltage breakdown fuses work with fixed, predetermined connecting cables with prefabricated cable length and a fixed cable cross-section.

Due to the specified connecting cable, the cross-section of the connecting cable is tuned to a maximum rated short-circuit rating. For installation sites with an actually lower short-circuit current, the line is oversized relative to the cross-section. With an actually higher short-circuit current, the cross-section can not be increased accordingly.

Another problem is the integration of known voltage breakdown fuses in electrical switchgear by incompatible fasteners.

When replacing the voltage breakdown fuses under operating conditions, it should be noted that as a rule an additional external short-circuit connection is necessary in order to be able to continue with the connection For reasons of personal safety, avoid fault voltage for impermissibly high contact voltages.

Also, previous solutions of the prior art have no indication of the condition on site or by remote access. For this reason, as a precaution, all voltage breakdown fuses are replaced in the event of a fault on the specific track sections in order to be able to resume rail operation as quickly as possible.

From the foregoing, it is therefore an object of the invention to provide a mounting housing arrangement for pulse current fixed integration at least one prefabricated voltage breakdown, in particular such a spark gap base, which allows easy replacement of a defective assembly and wherein in a quasi-standard housing arrangement different voltage breakdown fuses can be used with appropriately adjusted parameters are. The to be created mounting housing assembly should also allow the integration into electrical switchgear with there provided conventional fasteners.

The object of the invention is achieved by the combination of features according to the teaching of claim 1, wherein the dependent claims represent at least expedient refinements and developments.

According to the invention, the mounting housing arrangement for the pulse-current-proof integration of at least one prefabricated voltage breakdown fuse, in particular on a spark gap basis, comprises a base body of a pressure-resistant, insulating material. This main body can be manufactured inexpensively from a plastic material in injection molding or compression molding technology.

The base body has on at least one side an opening for receiving an insert in the form of the voltage breakdown, wherein the opening has a contour which fixes the side of the insert laterally. Starting from the opening and communicating therewith, a pressure equalization space extends within the body.

On opposite sides of the body there are contact plates, which are in mechanical communication with the body.

The opening extends to the contact plates and is closed by these.

Furthermore, the insert located in the opening comes into electrical connection with the surfaces of the contact plates which are located towards the opening.

On the outer sides of the contact plates oriented contact pieces are provided as external contacts in the longitudinal axis direction of the overall arrangement. These contact pieces can z. B. have the shape of a contact blade or even a contact pin and are used in this way in known, complementarily shaped terminals.

In one embodiment of the invention extensions in the form of mounting tabs are provided on the base body and / or on the contact plates. With the help of a tool that acts on the mounting tabs, the entire housing assembly can be inserted or removed in a switchgear.

Preferably, the mounting tabs are formed as part of the respective contact plate and formed on this.

The mounting tabs can be designed as a closed bracket with a return portion to allow a secure grip.

In one embodiment of the invention, a contacting and pressure sleeve for making the electrical connection between the insert and the respective contact plate is located in the opening. This makes it possible, in adaptation of the dimensions of the contacting and pressure sleeve and various inserts, d. H. Voltage breakdown fuses of different design and with different parameters to use without a separate body with different dimensions must be made.

Preferably, the voltage breakdown protection as an insert has a cylindrical shape with frontally opposite contact surfaces. Then, the opening is formed as a cylindrical bore, which is followed by a radial portion of the aforementioned pressure compensation chamber to this cylindrical bore area.

The contact plates with their contact pieces are interchangeable to allow adaptation to different contact terminal shapes. For this purpose, for. B. the contact plates are fastened by means of screws on the body.

The main body has on at least one outer side portion on a labeling surface with type and / or parameter information.

The opening in the base body is preferably formed as a through hole, which can be closed by the contact plates, wherein the contact plates non-positively and / or positively, for. B. with the aforementioned screws, are connected to the body.

Between the contact plates or the base body and a sealing and compensation ring is arranged. This preferably made of an elastic material compensating ring has a quasi-spring action, which is necessary for the current-stable contact, and at the same time prevents that by a too high contact pressure of the insert may be mechanically deformed and overloaded. Ultimately, the sealing and compensation ring ensures that the necessary IP degrees of protection can be maintained, ie no dust or moisture can penetrate into the interior of the body. In an additional embodiment, a current sensor for detecting the leakage current during operation is provided on or in the housing, it being possible to estimate the state, in particular the aging behavior of the voltage breakdown fuse, via a detected leakage current change.

The invention will be explained below with reference to exemplary embodiments and with the aid of figures.

Hereby show:

Fig. Ia and Ib embodiments of the mounting housing assembly with different contact pieces in an exploded view;

Fig. Ic is a cross-sectional view through the main body of

Mounting housing arrangement with one-sided already arranged contact plate together with mounting tab;

Fig. 2 is a perspective view of a complete mounting housing with contacts in the form of blade terminal contacts and

Fig. 3 is an illustration of a possible interconnection with external

Current sensor and control electronics.

The mounting housing assembly, as shown in FIGS. Ia and I b shown in exploded view, starting from a base body 1. The main body 1 may have the shape of a cylinder or else a cuboid.

In the main body 1, a preferably cylindrical through-bore 20 is introduced, which extends in the longitudinal axis direction of the main body 1.

The bore 20 is matched to the outer diameter of the insert 2, which corresponds to the prefabricated voltage breakdown protection (SDS). On an outer side of the main body 1, a labeling surface 8 is provided for necessary types and parameters.

A contact sleeve 5 whose diameter is in turn matched to the diameter of the insert 2, serves a length compensation and ensures the necessary contact connection between the end faces of the insert 2 and facing the main body 1 sides of the contact plates 3, which consist of a metallic material.

It should be noted at this point that the base body 1 is made of an insulating material and z. B. is produced in plastic injection molding.

An elastic sealing and compensating element in the form of a ring 4 is arranged at the two opposite ends of the main body 1 as an intermediate piece relative to the respective contact plate 3. With the help of screws 7 then attaching the contact plates 3 with the sealing and compensation ring 4 on the base body. 1

Formed on the contact plates 3, a mounting tab 9 is present, which allows easy handling of the housing assembly for insertion into corresponding terminals, as shown in FIG. 3 is allowed.

The embodiments according to FIGS. 1a and 1b differ in the shape of the contact pieces 6. In the solution according to FIG. 1a, a quasi-flat, knife-shaped contact is present here (see also FIG. 2). In contrast, in the variant according to FIG. 1 b, a rod-shaped contact piece 6 is present.

Radially spaced from the bore 20 extends in the interior of the main body 1, a pressure compensation chamber 10 in order to accommodate released in response to the spark gap gases without destroying the housing assembly can. A completely assembled housing assembly with internal voltage fuse shown in Fig. 2. The insertion of such a housing assembly with voltage fuse z. B. in a system according to the schematic diagram of FIG. 3 takes place with the aid of mounting tabs 9, by pushing in a contact socket 15, the z. B. may be formed in so-called Lyraform. Likewise, then serve the mounting tabs 9, resulting from the image plane of FIG. 3 forward, the easier removal and replacement of the overall arrangement.

According to the invention, a pulse-current-proof integration of the spark gap insert 2 is therefore carried out in the insulating body 1.

The selection of the material of the main body 1 and the structural design is made so that a safe behavior is given in case of overload. The internal geometry is designed so that with the additional pressure equalization chamber a defined pressure control is given in case of overload. Furthermore, the bore 20 mechanically fixes the spark gap insert.

As already stated, the outer geometry of the main body 1 can preferably be cylindrical, but also be executed in an e-cornered manner.

The contact plates 3 may have a crowned geometry such that the contact pressure is sufficient to control the short-circuit forces and arc arcs are avoided.

The dimensioning of the inner sleeve serving as a contact sleeve 5 in cross-section and material selection is designed so that the required surge current resistance is achieved.

The introduced between the contact plate 3 and the plastic housing or body 1 each element 4 in the form of a sealing and compensation ring is used to compensate for the tolerances of the individual located in the base body 1 components and ensures the elastic properties and its shape for compliance with the IP degree of protection, ie it is effectively prevented from entering moisture and dust.

At the same time, the compensating element on a spring action, which is necessary for the current-tight contact and prevents that may be overloaded mechanically by a too high contact pressure of the spark gap insert.

The contact pieces 6 may preferably be used as flat contacts, such. As knife contacts, but also be designed as plug contacts in a round shape. The special design is carried out depending on the receiving frame used or lower part of the overall arrangement (see Fig. 3).

The pluggable, located in the housing assembly

Voltage breakdown securing elements 11 and 11 'are shown in FIG. 3 received in a support frame 12 with appropriately designed contact sockets 15.

The support frame 12 is preferably carried out in a bipolar design for receiving two SDS elements. An SDS element is contacted (11) and another SDS element is in reserve circuit (H ').

As an alternative to equipping with two SDS elements, it is also possible to equip it with a single SDS element and a short-circuit bridge designed to be current-carrying and suitable for use in the corresponding contact sockets.

The recordings for the SDS elements are electrically connected in parallel. This parallel connection takes place via corresponding current-carrying connections 13 of the two SDS element recordings.

The external connection of the support frame via integrated in the support frame connecting terminals 14th Of course, multi-pole combinations of different terminals for receiving different connection cables are possible.

An additional design for quick mounting on DIN rail and thus the integration in electrical switchgear is within the meaning of the invention.

By an optionally provided monitoring device, a possible aging of the SDS elements can be detected. Aging can be detected by a correspondingly increased leakage current, which is above the maximum value indicated in the new state.

For this purpose, the integration of a monitoring device for the SDS elements in addition to the display device in the support frame is additionally possible.

This monitoring device consists of a current sensor 16 for leakage current monitoring and an electronic control unit 17 electrically connected to the sensor 16.

The current sensor 16 can be integrated in a connection path of the support frame, but also in the main body itself.

The control electronics can be adapted to the respective application by means of adjustable current thresholds.

Finally, the optional monitoring device allows for the detection of the response of the SDS elements. This is possible by measuring the fault current, which then exceeds an adjustable limit.

The exceeding of the limit value can alternatively or simultaneously for on-site display via a corresponding switching contact in a be integrated according to higher-level control device in the sense of a remote message.

A mechanical lock 18 or unlocking of the slots for the SDS elements prevents both slots being open at the same time, ie. H. are unpopulated. The mechanical locking and unlocking of the two slots also prevents a short-circuited SDS element from being removed before a second parallel SDS element is inserted.

The presented solution results in simpler and more flexible connection options due to an extended terminal design. In addition, a faster interchangeability of the short-circuited fuse inserts and thus a reduction of the work steps is possible. The design of the contacts allows integration into conventional switchgear. An on-site display increases personal safety and thus ease of use. It is thereby possible a faster and easier detection of faulty, short-circuited voltage breakdown.

Due to the adjustable current detection also possible stray currents, the system availability is increased because an aging of the individual voltage breakdown fuses can be detected and a timely, precautionary replacement of aged elements vornehmbar.

The respective mounting housing arrangement with SDS element accommodated therein can be safely replaced with the appropriate safety equipment by the service personnel, even if the trolley short circuit is still present, with the help of the mounting lugs attached to the housing. The pending external voltage can reach a maximum of the operating voltage of the corresponding voltage fuse. Compliance with the corresponding voltage-time characteristics is guaranteed. Still applied external voltages are displayed with the result of improved personal safety. LIST OF REFERENCE NUMBERS

1 basic body / plastic housing

2 insert / voltage fuse pill

3 contact sheet

4 sealing and compensation ring

5 contact sleeve

6 contact piece

7 screw

8 Nameplate / labeling area

9 mounting bracket

10 pressure compensation room

11 Slot 1 for SDS element 11 'Slot 2 for SDS element

12 support frame

13 current-carrying compound

14 terminal

15 contact socket

16 current sensor

17 control electronics

18 mechanical lock 20 opening

Claims

claims

1. mounting housing arrangement for pulse current fixed integration of at least one prefabricated voltage breakdown, in particular on

Fun kenstrecken base, characterized in that a base body (1) made of a pressure-resistant, insulating material is provided, which on at least one side has an opening for receiving an insert (2) in the form of voltage breakdown, wherein the opening (20) has a contour has, which fixes the insert (2) fixed and starting from the opening (20) starting a pressure compensation chamber (10) within the base body (1), on opposite sides of the base body (1) contact plates (3) are located, which are connected to the main body (1) are in mechanical connection, wherein the opening (20) extends to the contact plates (3) and is closed by these and further in the opening (20) located insert (2) in electrical connection with the contact plates (3) has reached and the outer sides of the contact plates (3) in the longitudinal axis direction of the overall arrangement oriented contact pieces (6) as external contacts.

2. Arrangement according to claim 1, characterized in that on the base body (1) and / or the contact plates (3) extensions in the form of mounting tabs (9) are provided.

3. Arrangement according to claim 2, characterized in that the mounting tabs (9) are part of the respective contact plate (3) and integrally formed thereon.

4. Arrangement according to one of the preceding claims, characterized in that in the opening (20) has a contacting and pressure sleeve (5) for manufacturing the electrical connection between the insert (2) and the respective contact plate (3) is located.

5. Arrangement according to one of the preceding claims, characterized in that the voltage breakdown fuse insert (2) has a cylindrical shape with frontal contact surfaces.

6. Arrangement according to claim 5, characterized in that the opening (20) is designed as a cylindrical bore, which is connected via a radial portion of the pressure compensation chamber (10).

7. Arrangement according to one of the preceding claims, characterized in that the contact plates (3) with contact pieces (6) are exchangeable to make an adaptation to different contact terminal shapes.

8. Arrangement according to one of the preceding claims, characterized in that the base body (1) on an outer side portion has a labeling surface (8) with type and parameter information.

9. Arrangement according to one of the preceding claims, characterized in that the opening (20) is formed as a through hole, which is closable by the contact plates (3), wherein the contact plates (3) non-positively and / or positively connected to the base body ,

10. Arrangement according to one of the preceding claims, characterized in that between the contact plates (3) and the base body (1) each have a sealing and compensation ring (4) is arranged.

11. Arrangement according to one of the preceding claims, characterized in that on or in the housing (1) a current sensor (16) is provided for detecting the leakage current during operation, wherein an estimated change in the leakage current an estimate of the aging behavior

Voltage breakdown fuse occurs.