WO2000019475A1 - High-voltage fuse and power distribution network - Google Patents

Abstract

The invention relates to a high-voltage fuse in which a cover plate (2) of a first electrical connection is connected to a separating plate (6) via a fuse element consisting of silver-coated strips (7) in an electrically conductive manner. A reactor is connected to said separating plate, which reactor has a coil (8) enclosing a core which is provided in the form of a solid ferrite bar (9). Said coil connects the separating plate (6) to a cover plate (4) of a second electrical connection in an electrically conductive manner. Alternatively, in order to save space, the fuse element can be arranged in an opening in the hollow core and can be connected to the coil via a return line. Said high-voltage fuse provides a means of connecting branches of a power supply system to a low-voltage line and a means of preventing the distribution of the high-frequency signals used for communication between appliances of one branch to other branches.

Description

 DESCRIPTION

POWER FUSE PROTECTION AND POWER DISTRIBUTION NETWORK

Technical field

The invention relates to a high-voltage fuse according to the preamble of claim 1. Such

Fuses are mainly used as line protection fuses in low-voltage networks and are usually arranged in transformer stations, distribution points and house connection boxes. They can interrupt overcurrents of the order of a few hundred amperes. In addition, the invention relates to a power distribution network according to the preamble of claim 13.

State of the art

Generic high-current fuses are available in various sizes and designs in the trade. For example, the brochure 'NH fuse-links' from Rockwell Automation shows various such fuses, which correspond to different sizes of the standards DIN 43620 and IEC 269-2-1 in terms of their dimensions. Such fuses have a very low impedance for practically all frequencies occurring in the network. Their function is entirely limited to switching off overcurrents.

However, it is known that high-frequency voltages and currents arise in power distribution networks due to switching operations and other influences, which quickly spread over the network and u. U. Certain consumers disturbed. The load on the network with high-frequency interference is particularly unpleasant when it is over certain parts of the same, e.g. B. within a building, messages can also be transmitted by means of high-frequency signals.

Presentation of the invention

The invention is based on the idea of designing known high-voltage fuses of the generic type in such a way that they largely intercept interference signals of the type described. Since such a high-voltage fuse usually connects a smaller network area, in particular one that is limited to a single building or a building complex, to the rest of the network due to its conventional function, and the transmission of messages via the network is usually also limited to such areas, it is very conveniently positioned to protect the areas from high-frequency interference from the rest of the network.

The heavy current fuse according to the invention is now designed in such a way that, in addition to the interruption of overcurrents, it also largely suppresses high-frequency signals, in particular in a frequency range between 1 MHz and 40 MHz, as is primarily used for message transmission. It can be designed in such a way that it can be used for electrical design and also for

Dimensions at least like this. A well-known, standard high-voltage fuse is that it can replace it without any changes to the slot or the surrounding area.

The advantages achieved by the invention lie primarily in the fact that, in a very simple and cost-effective manner, cheaper ones are also available in existing systems Impedance ratios for the transmission of messages are established by setting them at the coupling points of individual branches in such a way that the large-scale propagation of high-frequency signals via the power distribution network is largely prevented.

In particular, the penetration of high-frequency interference signals into a branch of a power distribution network, in which messages are also transmitted, is greatly reduced and a more favorable signal-to-interference ratio for message transmission is established. Conversely, unwanted outflow of message signals from the branch is largely prevented. Interfering influences are thus prevented or at least greatly weakened and the undesired electromagnetic radiation is also reduced. The mutual decoupling of different branches in the area of the frequencies used for message transmission allows multiple use of these frequencies in the network and thus an increase in the overall message capacity thereof. At the same time, the quality of the

Message transmission within the individual branches improved.

Brief description of the drawings

The invention is explained in more detail below with reference to figures which only represent an exemplary embodiment. Show it

1 shows a longitudinal section through an inventive high-current fuse according to a first embodiment, with an uncut throttle,

2 shows a longitudinal section corresponding to FIG. 1, along II-II there, 3 shows a cross section along III-III in FIG. 1,

4 shows a longitudinal section through an inventive high-current fuse in accordance with a second embodiment, with a partially uncut throttle,

5 shows a cross section along V-V in FIG. 4,

6 shows a longitudinal section through a high-voltage fuse according to the invention in accordance with a third embodiment, with an uncut throttle,

7 is a longitudinal section corresponding to FIG. 6, along VII-VII there,

8 shows a cross section along VIII-VIII in FIG. 6,

9 shows a longitudinal section through an inventive high-current fuse in accordance with a fourth embodiment, with an uncut throttle,

10 shows a cross section along X-X in FIG. 9,

11 is a longitudinal section corresponding to FIG. 9, but with a cut throttle,

Fig. 12 shows a longitudinal section through a high-current fuse according to the invention according to a fifth

Embodiment, directly behind the wall in front,

13 shows a cross section along XIII-XIII in FIG. 12,

14 shows a longitudinal section along XIV-XIV in FIG. 13, 15 shows a longitudinal section through a high-voltage fuse according to the invention in accordance with a sixth embodiment, directly behind the wall in front,

16 shows a cross section along XVI-XVI in FIG. 15,

17 shows a longitudinal section along XVII-XVII in FIG. 16,

18 shows a longitudinal section through a high-voltage fuse according to the invention in accordance with a seventh embodiment, the basic structure of which corresponds to that according to the fifth embodiment,

19 is a side view corresponding to arrow XIX in Fig. 18,

20 is a side view corresponding to arrow XX in Fig. 18,

21 shows a longitudinal section through a high-voltage fuse according to the invention in accordance with an eighth embodiment, the basic structure of which corresponds to that according to the sixth embodiment,

22 is a side view corresponding to arrow XXII in Fig. 21,

Fig. 23 is a side view corresponding to arrow XXIII in Fig. 18 and 24 schematically shows a power distribution network in which starter current fuses according to the invention are used.

Ways of Carrying Out the Invention

A high-current fuse according to the invention in accordance with a first embodiment (FIGS. 1-3) has an approximately cuboid housing 1 made of electrically insulating material, preferably ceramic, which has a first electrical connection at the opposite ends in the longitudinal direction with a first

End plate 2, which carries a contact knife 3 on the outside and a second electrical connection with a second end plate 4, which carries a contact knife 5 on the outside. The closing plates 2, 4 closing the housing 1 are made, for. B. made of aluminum, the contact knife 3, 5 consist of a copper alloy and are silver-plated.

The interior of the housing is by a partition plate 6 made of electrically conductive material, for. B. Aluminum divided into two successive sections in the longitudinal direction. The somewhat longer first section, which lies between the end plate 2 of the first electrical connection and the partition plate 6, contains a fusible conductor, which connects the end plate 2 to the partition plate 6 in an electrically conductive manner. It consists of three silver sheathed bands 7 arranged in a row in a row and is designed in a known manner so that in the event of overcurrent it melts according to a standardized characteristic curve according to a response time dependent on the current intensity and interrupts the current.

In the section between the partition plate 6 and the end plate 4 of the second electrical connection A choke is arranged inside the housing. It consists of a cylindrical winding 8, which connects the separating plate 6 to the end plate 4 in an electrically conductive manner, and a continuous core made of a ferromagnetic, preferably electrically insulating material, in particular ferrite, which as a round, lying in the axis of the winding 8 and surrounded by it Rod 9 is formed. The inductance of the choke is selected so that its impedance is negligibly small at frequencies of the order of magnitude of the mains frequency, that is to say approx. 50 Hz, but very high at high frequencies from 1 MHz to 40 MHz.

The heavy current fuse can correspond to the dimensions of sizes 1-3 of the DIN 432620 standard and z. B. be designed for 400 V and 400 A. It can be used at any time instead of conventional fuses that comply with this standard.

A second embodiment (FIGS. 4, 5) of the high-voltage fuse according to the invention differs from the first only in that the winding 8 is somewhat smaller and the core, in addition to a rod 9 arranged in the axis thereof, also has a shell surrounding the winding 8 on the outside , which consists of two half-shells 10a, b connected to the head ends of the rod 9, which are separated by a central air gap 11. The shell has two diametrically opposed sector-shaped openings 12a, which extend over its entire length and through which the winding 8 is electrically conductively connected to the separating plate 6 and the end plate 4.

A third embodiment (Fig. 6-8) largely corresponds to the first, but the core, which in turn is designed as a solid round rod 9, extends essentially over the entire length of the housing 1 and extends from the End plate 2 of the first electrical connection up to the end plate 4 of the second electrical connection. The three silver sheath strips 7 of the fuse element are arranged around the rod 9. The embodiment is characterized by particularly good mechanical stability.

A fourth embodiment (FIGS. 9-11) of the high-voltage fuse according to the invention shows a different structure. The core is again designed as a rod 9, which is surrounded by the winding 8. However, both are of rectangular cross section, that is to say cuboid, and the rod 9 is hollow, it has a central passage running through in the longitudinal direction, in which the fusible conductor is arranged, which here consists of a single silver sheath band 7. The winding 8 is separated from the end plate 2 of the first electrical connection by an insulation layer 13 and the silver sheath band 7 from the end plate 4 of the second electrical connection by an insulation layer 14.

The silver-coated tape 7 connects to the first end plate 2 through an opening in the first insulation layer 13. Its opposite end is an intermediate plate 15 resting on the second insulation layer 14 with a z. B. formed as a return wire return line 16, which runs back in a groove on the outside of the rod 9 against the silver sheath band 7 to the next to the first end plate 2 end of the winding 8. The end of the winding 8 opposite this is finally connected to the end plate 4 by an opening in the second insulation layer 14. The current path thus runs from the end plate 2 through the silver jacket band 7, the intermediate plate 15, back through the return line 16 and after a new reversal of direction through the winding 8 to the end plate 4. This embodiment is particularly space-saving, in particular it can be very short. It can therefore be manufactured in the dimensions of size 00-3 of the DIN 43620 standard and can replace conventional heavy-current fuses that comply with this standard at any time.

A fifth embodiment of the high-current fuse according to the invention (Fig. 12-14) corresponds in its basic structure to the fourth embodiment, but the winding 8 is arranged next to the fuse element, which is arranged between the contact knife 3 of the first electrical connection and an intermediate plate 15 and again from there are three parallel silver jacket bands 7. The intermediate plate 15 is connected by means of a return line 16 to the end of the winding 8 which is closest to the first electrical connection and whose opposite end abuts the end plate 4 of the second electrical connection. An insulation layer 14 lies between the latter and the intermediate plate 15. The winding 8 surrounds a core which is covered by a

Insulation layer is surrounded. It can in turn be designed as a solid round rod 9 or also consist of several parallel rods.

The current path runs from the contact knife 3 of the first electrical connection via the silver jacket strips 7 to the intermediate plate 15 and further via the return line 16, through the winding 8 and via the end plate 4 to the contact knife 5 of the second electrical connection.

According to a sixth embodiment, the high-current fuse according to the invention (FIGS. 15-17) is similar with a winding 8 arranged between the contact blades 3, 5 and a fusible conductor arranged as a silver sheath band 7 constructed like the inventive high-current fuse according to the fifth embodiment. The contact plate 3 of the first electrical connection is connected to the end plate 2 thereof, which is connected via the fuse element to an intermediate plate 15 which is arranged at a distance from the end plate 4 of the second electrical connection. The intermediate plate 15 is connected via the return line 16 to that end of the winding 8 which is closest to the connection plate 2 of the first electrical connection and whose opposite end abuts the end plate 4 of the second electrical connection, which in turn carries the contact blade 5 of the same.

The winding 8 in turn surrounds a core which is designed as a solid round rod 9 and is surrounded by an insulation which at the same time forms an insulation layer 13 which separates the winding 8 and the return line 16 from the end plate 2 of the first electrical connection and an insulation layer 14 , through which the winding 8 is connected to the end plate 4 of the second electrical connection.

In the last two versions described, the dimensions of the high-current fuse according to the invention exceed those of known generic high-current fuses, but this can be limited to only one dimension transverse to the connection between the contact blades, while the other dimensions in turn correspond to the standard dimensions of known generic high-current fuses, so that they are normally used nothing stands in the way of the inventive high-current fuse in a standard slot. The basic structure of a high-current fuse according to the invention in accordance with a seventh embodiment (FIGS. 18-20) corresponds to that according to the fifth embodiment. However, details of the constructive implementation are shown in the figures. The contact knife 3 of the first electrical connection is mechanically and electrically conductively connected to a first end plate 17, which closes a fuse housing 18 made of electrically insulating material on one side and is closed on the opposite side by a second end plate 19. The fuse housing 18 contains three parallel silver jacket bands 7, which connect the first end plate 17 and the second end plate 19 in an electrically conductive manner. The first end plate 17 carries a folding detector 20 next to the contact knife 3. The second end plate 19 is provided with a

Bolted intermediate plate 15, which forms an integral Z-shaped component with a return line 16 returning next to the fuse housing 18 and a connection plate 21 arranged next to the first end plate 17. The first end plate 17 and the connecting plate 21 are screwed together for mechanical reinforcement of the high-current fuse with a connection plate 22 made of electrically insulating material and overlapping with both.

Between the connection plate 21 and a front plate 23, which is arranged at a distance in front of the second end plate 19 and is connected to the same via spacers 24 made of electrically insulating material and which carries the contact knife 5 of the second electrical connection on the outside facing away from the second end plate 19, an inner winding 8a and an outer winding 8b are arranged coaxially, which are electrically connected in parallel. The reason for this arrangement lies in the following: The windings 8a, b consist of enamel-insulated winding wire of approximately rectangular cross-section, with the purpose of achieving this a high number of turns for a given cross section, the longer side edge of the rectangle is aligned radially. The radial expansion of the winding wire is limited, however, by the fact that no undesirable twists, upsets or bends may occur during the winding of the wire, which would increase the distance between the turns. In order to achieve a high current carrying capacity despite the resulting cross-sectional limitation, the current is distributed over two windings.

Inside the inner winding 8b is one of one

Insulating sleeve 25 surrounded ferrite core 9 arranged and fixed by a cover 26 which closes an opening in the front panel 23. Instead of the solid rod-shaped ferrite core, a ferrite tube or a parallel arrangement of thinner ferrite rods or tubes can also be provided. Ferrite cores of different lengths can also be used, which are compensated for by lids or inserts of different thicknesses.

The described high-current fuse is suitable for high currents and is still compact and mechanically very stable and can be used in an ordinary slot. It is generally surrounded by a housing (not shown here) made of electrically non-conductive material, which leaves free the fronts formed by the first end plate 17, the connecting plate 22 and the connecting plate 21 on the one hand and the front plate 23 on the other hand. To facilitate insertion into and removal from a slot, the connection plate 21 and the front plate 23 are each provided with a pull tab 27.

The basic structure of a high-current fuse according to the invention in accordance with an eighth embodiment (FIGS. 21-23) corresponds to that according to the sixth Embodiment, however, the figures again show details of the structure. The contact sword 3 of the first electrical connection is screwed here to a front plate 23, which in turn is screwed to a first end plate 17 to which a fuse housing 18 connects and is arranged in the same

Silver-coated tapes (not shown), which produce an electrically conductive connection between the first end plate 17 and a second end plate 19, which closes the fuse housing 18 at the opposite end. The first end plate 17 carries a folding detector 20.

The second end plate 19 is screwed to a bent connection lug 28 of the return line 16, which is led back along the fuse housing 18 and bends into a connection plate 21 parallel to the front plate 23 and spaced apart from it. Between the connection plate 21 and a closure plate 29 made of electrically insulating material, which carries an end plate 4 and the screwed contact sword 5 of the second electrical connection, there is a turn 8, which on the one hand with the connection plate 21, on the other hand through the closure plate 29 and over the end plate 2 is electrically conductively connected to the contact sword 5. The winding 8 in turn runs around a ferrite core 9 surrounded by an insulating sleeve 25. For the mechanical reinforcement of the high-current fuse, the closure plate 29 is screwed to a connecting tab 30 projecting from the return line 16. A certain minimum distance must be maintained between the end plate 4 and the connecting tab 30 so that the u. Considerable voltages, which can occur due to the inductance of the network when the high-voltage fuse is blown, do not lead to flashovers. In addition to the winding 8, spacers 24 made of electrically non-conductive material are arranged, which connect the end plate 2 to the closing plate 29, so that the heavy-current fuse is mechanically stable and compliant with the standards, independently of the winding 8

Dimensions is set. Pull tabs 27 are in turn screwed onto the end plates 17, 19.

24 schematically shows a power distribution network in which high-voltage fuses according to the invention are used. From a transformer 31 - it can also be another junction such. B. act a house junction box - one goes

Low-voltage line 32, from which several branches 33 branch, each of which is guided via a high-current fuse 34 according to the invention, behind which it branches further. The individual branches 33 can each supply one building. Transmitters and receivers 35 are connected to each branch, e.g. B. each a PLC master and various devices connected to the branch (not shown), with which it uses high-frequency signals such. B. communicates with carrier frequencies in the range between 1 MHz and 40 MHz. The signals are coupled galvanically or capacitively. Since they are strongly attenuated by the high-current fuses 34, the signals are essentially limited to a single branch, so that interference between the different branches does not lead to interference even if the frequency bands overlap or are so close that otherwise interfering interactions occurred. As a rule, it must be assumed that the transmitting and receiving devices 35 work synchronously, that is to say they send and receive at the same time.

Claims

PATENT CLAIMS 1. A high-voltage fuse with a housing (1) made of electrically insulating material and, at opposite ends in the longitudinal direction thereof, a first electrical connection and a second electrical connection, which are connected in an electrically conductive manner via a fusible conductor arranged in the housing (1), characterized in that that the electrically conductive connection between the first electrical connection and the second electrical Connection is made via a choke arranged in the housing (1) and in series with the fuse element. 2. Heavy current fuse according to claim 1, characterized in that the choke at least one Includes winding (8) and has a core made of ferromagnetic, in particular electrically insulating material, which is magnetically coupled to the winding (8). 3. Heavy current fuse, according to claim 2, characterized in that the core comprises a rod (9) which is surrounded by the winding (8). 4. Heavy current fuse according to claim 2 or 3, characterized in that the core comprises a shell which at least partially surrounds the outside of the winding (8). 5. Heavy current fuse according to claim 4, characterized in that the shell has two opposing sector-shaped openings (12a, 12b). 6. High-voltage fuse according to claim 4 or 5, characterized in that the shell is divided into two half-shells (10a, 10b) by a circumferential air gap (11). 7. Heavy current fuse according to one of claims 1 to 6, characterized in that the fuse element and the choke are arranged in succession in the longitudinal direction in the housing (1). 8. Heavy-current fuse, according to claim 7, characterized in that the part of the housing interior containing the fuse element and the part of the housing containing the choke are separated from one another by a transverse partition plate (6). 9. Heavy current fuse according to one of claims 1 to 6, characterized in that the throttle Fuses surrounding. 10. High-voltage fuse according to claims 3 and 9, characterized in that the rod (9) is hollow with a bushing receiving the bushing and the winding (8) with the fuse by an outside of the rod (9) arranged opposite the fuse Return is connected. 11. Heavy current fuse according to one of claims 1 to 6, characterized in that the fuse element and the choke are arranged parallel to one another in the longitudinal direction in the housing (1). 12. Heavy current fuse according to one of claims 1 to 11, characterized in that the choke comprises at least two coaxially arranged windings (8a, 8b) connected in parallel. 13. Power distribution network with a plurality of galvanically connected branches (33), characterized in that in each branch (33) at the input there is a heavy-current fuse (34) according to one of claims 1 to 11.