DE20014631U1 - Power supply network and device for use in a coupling point of a power supply network - Google Patents

Description

The invention relates firstly to a power supply network according to the preamble of claim 1.

Such power supply networks are well known and are used worldwide. Power plants that generate the electrical power of the power supply network are connected to high-voltage lines.

30 substations reduce the operating voltage of the high-voltage lines from 380 kV, 220 kV or 110 kV to medium voltage in the range of about 20 kV. Medium voltage lines connect the substations with so-called local network transformer stations. At the local network transformer stations, the medium voltage is reduced to 400

35 or 240 volts low voltage, which can be supplied directly to end users. The medium voltage lines connect various local network transformer stations with each other.

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(Bank code 330 400 01) 4 034 823

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DE 121068676

Eichhoff GmbH

Each local network transformer station is assigned an area in which a large number of end users are located. Each end user is normally directly connected to only one local network transformer station.

The low-voltage side of a local network transformer station is electrically separated from the low-voltage side of a neighboring local network transformer station. Two neighboring local network transformer stations are normally only connected to each other via a medium-voltage line.

If required, however, it is possible to connect two neighboring local network transformer stations directly to one another via redundant low-voltage lines or redundant medium-voltage lines. Such a need arises, for example, if a local network transformer station fails or if a particular local network transformer station is no longer able to supply the area assigned to it with electrical power due to lightning strikes or other faults. In this case, the neighboring local network transformer station takes over the supply of electrical power to the area of the failed local network transformer station. The redundant lines are also short-circuited for this purpose during regular maintenance or conversion work.

In order to be able to easily establish such a connection if necessary, coupling points are provided in the local network transformer stations into which so-called NH or HH fuses can be inserted. These NH (NH means low-voltage side) or HH fuses (HH means medium-voltage side) are compact and have two blade strips that protrude from the fuse housing. These blade strips are designed like snap-in rails and are used for mechanical support and electrical contact in the coupling point.

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Within such a NH or HH fuse, a special melting band is arranged in a sand filling.

Starting from a power supply network according to the preamble of claim 1, the invention is based on the object of developing the power supply network in such a way that the redundant low-voltage lines or the redundant medium-voltage lines can also be used under normal conditions.

The invention solves this problem with the features of claim 1 and is accordingly characterized in that a device is arranged in the coupling point which allows high-frequency signals to pass and blocks low-frequency voltages (50 Hz).

The invention recognizes that the existing redundant low-voltage lines and redundant medium-voltage lines represent an unused potential for data transmission. By arranging a device in the coupling point according to the invention that allows high-frequency signals to pass and blocks low-frequency voltages, it is possible to transmit data between two neighboring areas of two neighboring local network transformer stations via the existing redundant lines, but at the same time to maintain an electrical separation of these two areas. The electrical supply of the respective areas with mains voltage continues to take place exclusively via the respective local network transformer station.

This includes the advantage that even in the event of a fault, i.e. if a conventional NH or HH fuse is used instead of a device according to the invention, data transmission via the coupling point is still possible. For the relatively short moment when the device according to the invention used needs to be replaced by an NH or HH fuse,

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Simple means can be used to ensure that there is no interruption in data transmission.

For example, data transmission can be carried out by telephone, fax, email or internet. The power distribution network according to the invention now makes it possible to transmit this data across regions without making any structural changes to the power supply network.

According to a further embodiment of the invention, the coupling point is designed to accommodate conventional NH or HH fuses. This makes it clear that no structural changes need to be made to a coupling point of a state-of-the-art power supply network. Instead of the NH or HH fuses known in the state of the art, which are only inserted into the coupling point when required, the coupling point now accommodates the device according to the invention that allows high-frequency signals to pass through and blocks low-frequency voltages.

According to a further advantageous embodiment of the invention, the device essentially has the external design of a conventional NH or HH fuse. This also offers the advantage that no structural changes have to be made to the coupling point. In addition, the device is particularly easy to construct, since at least some of the known elements can be used.

According to a further advantageous embodiment of the invention, the device has at least one capacitor, in particular a wound capacitor. A capacitor is the simplest electronic component imaginable, which allows high-frequency signals to pass through and blocks low-frequency voltages (50 Hz). Commercially available elements can thus be used, which allows a certain

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Cost savings are possible. In addition, particularly safe components can be used.

According to a further advantageous embodiment of the invention, the device has a housing made of porcelain. In this way, it is possible to meet special safety requirements that are placed on a component in constant use in a local network transformer station.

According to a further advantageous embodiment of the invention, the device has a fuse, in particular in the order of magnitude of 50-250 mA. This has the advantage that a particularly high level of reliability can be achieved in this way and it is ruled out that, for example, if a capacitor fails, the electrical separation (meaning the 50 Hz separation) is eliminated.

According to a particularly advantageous embodiment of the invention, the device has additional electronic components for influencing signals, in particular for attenuating, amplifying, suppressing interference, blocking or the like. Here, the invention recognizes that the installation space available in the housing of a conventional NH or HH fuse can also be used for additional electronic components and such a device can perform completely new additional functions.

Furthermore, the invention relates to a device according to the preamble of claim 12.

One such known device is an NH or HH fuse. These NH or HH fuses are used in coupling points of a local network transformer station of a power supply network in order to create redundant low-voltage circuits if necessary.

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to interconnect redundant medium-voltage lines or redundant medium-voltage lines.

The known device is compact and essentially cuboid-shaped and has two blade strips on the side that are used for insertion into corresponding holders in the coupling point. The blade strips have the function of both mechanical contact and electrical contact.

The known device has a fuse inside its housing which is activated at very high currents, for example 1200 A.

Based on the known device, the invention is based on the object of developing the device in such a way that the redundant low-voltage lines or redundant medium-voltage lines can also be used under normal conditions.

The invention solves this problem with the features of claim 12, and accordingly characterized in that the device comprises at least one capacitor which blocks low-frequency voltages (50 Hz) and allows high-frequency signals to pass.

According to the invention, the device is no longer a fuse that is only used when necessary, but a device that is also located in the coupling point during normal operation and can be used for data transmission. At the same time, the device according to the invention ensures electrical isolation in the sense that mains voltage, i.e. 50 Hz voltage, cannot pass through the coupling point.

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The device according to the invention is used in an existing power supply network in place of the NH or HH fuse. This is in itself pointless, since electrical isolation should always be ensured in the area of the coupling point.

Further embodiments of the device according to the invention have advantages which correspond to the advantages of the embodiments of the power supply network according to the invention.

Further advantages of the invention emerge from the uncited subclaims and from the following description of an embodiment shown in the figures. In the figures show

Fig. 1 shows schematically the structure of a power supply network according to the invention,

tation,

Fig. 2 shows a perspective view of the device according to the invention.

Fig. 3 in partially sectioned view the device according to Fig. 2 and

Fig. 4 is a plan view of the device of Fig. 3 according to view arrow IV in Fig. 3.

Fig. 1 shows a schematic diagram of a power supply network 10, as is known in principle in the prior art. A power plant 11 produces electrical energy and is connected to a substation 13 via high-voltage lines 12, which transport the electrical power at a voltage of 380/220 or 110 kV. There, the high voltage is reduced to medium voltage, i.e. voltages between 6 and 30 kV. The medium-voltage network is mesh-shaped or star-shaped and carries the electricity via medium-voltage lines 14 to the immediate vicinity of the consumers.

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The medium voltage is transformed down to 400 or 240 volts at a number of local network transformer stations 15a, 15b, 15c. Low-voltage lines 16 lead from the local network transformer stations 15a, 15b, 15c to the consumers 17a, 17b, 17c.

Each transformer station 15a supplies a specific

Area exclusively with electricity. In the embodiment according to Fig. 1, four consumers 17a are assigned to the local network transformer station 15a. Accordingly, four houses 17b are assigned as end consumers to a second local network transformer station 15b.

Two adjacent transformer stations 15a, 15b are normally directly connected to one another via a medium-voltage line 14. However, this connection only exists on the medium-voltage side of the local network transformer stations 15a, 15b. On the low-voltage side, the two adjacent local network transformer stations 15a, 15b are electrically separated from one another in order to achieve predictable power situations.

In the event of faults, failures, but also due to maintenance work or reconstruction work, the situation can arise that a local network transformer station 15a fails and the supply area assigned to it, i.e. in this case the consumers 17a, must be supplied from the neighboring local network transformer station 15b. For this purpose, the state-of-the-art power supply network has redundant low-voltage lines 19, which are shown in dashed lines in Fig. 1 and connect two local network transformer stations 15a, 15b, 15c to each other. The redundant low-voltage line 19 between the local network transformer stations 15a and 15b consists of two sections 25 and 26. The upper section 25 of the redundant low-voltage line 19 according to Fig. 1 connects the local network transformer station 15a with a coupling point 21. The lower section 25 of the redundant low-voltage line 19 according to

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Fig. 1 lower section 26 of the redundant low-voltage line 19 connects the local network transformer station 15b with the coupling point 21.

In the state of the art, the coupling point 21 is designed to be electrically open, i.e. there is no electrical contact between the two sections 25 and 26 of the redundant low-voltage line 19.

It should be mentioned here that the coupling point 21 itself is basically arranged in a local network transformer station 15a, 15b, 15c, and is shown in Fig. 1 arranged at a distance from the local network transformer stations 15a, 15b, 15c merely for the sake of clarity.

In the state of the art, an NH fuse is inserted into such a coupling point 21 if necessary, for example if the area formed by the consumers 17a is to be supplied by the local network transformer station 15b. This therefore involves short-circuiting the open coupling point 21, whereby the limitation of the maximum current by the fuse ensures that manageable power situations occur.

According to the invention, it is now provided to insert a device 24 into the coupling point 21 in the normal case, i.e. when there is no fault, which device enables a transmission of electrical signals across the coupling point 21, but blocks alternating voltage in the range of 50 Hz.

In this way, an exchange of information can take place between, for example, the consumers 17a of the area of the local network transformer station 15a and the consumers 17b of the area of the local network transformer station 15b via the redundant low-voltage line 19 without any structural changes having to be made to the power supply network 10.

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For example, the area of the consumers 17c of the local network transformer station 15c can be connected via the control center 22 of an energy supply company and via a connecting line 23. Such a connection is also referred to as a PLC (Power Line Communication) connection, which is basically known in the state of the art.

Such PLC connections are relatively complex. In particular, the installation effort is relatively high, as work must sometimes be carried out under life-threatening conditions because the work involves changes to the power grid 10.

Once the local network transformer station 15c has been provided with a PLC connection 23, it is no longer necessary to connect the power supply company's control center 22 directly to other local network transformer stations 15a or 15b and to provide direct PLC connections. The existing redundant low-voltage lines 19 can be used as cross connections with the device 24 according to the invention and can be connected directly in the simplest possible way.

Basically, it is pointed out that redundant medium-voltage lines 18 are also present in a power supply network 10 of the state of the art. Such redundant medium-voltage lines 18 connect local network transformer stations 15a, 15b, 15c to one another on the medium-voltage side in the event of a fault in the medium-voltage line 14 or a fault in a local network transformer station. Coupling points 20 are also provided in the local network transformer stations 15a, 15b, 15c, into which so-called HV fuses can be inserted if necessary, which have the same function as the NH fuses described above. The device 24 according to the invention can also be inserted into these coupling points 20.

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whereby only a slightly different external design of an HV fuse in comparison to the NH fuse needs to be taken into account.

In Fig. 1, the coupling points 20 of the redundant medium-voltage lines 18 are also shown at a distance from the local network transformer stations 15a, 15b, 15c for the sake of clarity. In fact, the coupling points 20 are located at the local network transformer stations 15a, 15b, 15c.

Fig. 2 shows an embodiment of the device 24 according to the invention. It is essentially compact and comprises a housing 27 which is cuboid-shaped. The housing 27 is preferably made of porcelain.

The upper and lower end faces of the essentially hollow-cylindrical housing 27 as shown in Fig. 2 are screwed to cover plates 29. Handling parts 36 are provided in edge areas of the cover plates 29.

Referring to Fig. 2, blade strips 28 emerge from the housing 27 upwards and downwards. These are hooked in the manner of snap-in rails into corresponding receptacles in a coupling point 20, 21 (not shown) of a local network transformer station 15a, 15b, 15c.

Fig. 3 and 4 partially show the interior of the device 24 according to the invention as shown in Fig. 2.

As is particularly clear from Fig. 3, the upper blade strip 28 in relation to Fig. 3 is connected to a fuse 30 via an electrical line 32. This fuse 30 is designed for a range of 50 - 250 mA. In principle, however, it is also possible to use fuses with a maximum current of up to 1 A. This clearly shows that

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lent that electrical power should not be transmitted through the coupling point 20, 21. Only data signals can pass through.

The fuse 30 is connected via an electrical line 33 to a capacitor 31, which in the exemplary embodiment is designed as a capacitor winding. In an advantageous embodiment, there are two capacitor windings that are connected in series.

The impedance of the device 24 is adapted to the impedance of the local network transformer station 15a, 15b, 15c of the power supply network 10. In particular, the capacitance of the capacitor 31 in the exemplary embodiment is 0.01 μΩ.

The capacitor 31 is connected via a further electrical line 34 to the lower blade strip 28 with respect to Fig. 3.

All electronic components 30, 31, 32, 33, 34 are encapsulated with a potting compound 35 in such a way that the entire interior of the porcelain housing 27 is filled.

Advantageously, the encapsulation is flame-retardant and consists, for example, of polybutylene FR (60) according to DIN EN ISO 1043-4.

The external design of the device 24 according to the invention thus corresponds essentially to the external design of a known NH or HH fuse. The device 24 according to the invention is matched to the coupling point 20, 21, in particular in terms of its dimensions and measurements.

The device 24 shows in its representation according to Fig. 2 to 4 blade strips 28, which engage in terminals (not shown) of the coupling point 20, 21 (also not shown). However, the invention also provides for the device 24 to be fitted with

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Knife strips 28 are provided with knife clamps (not shown) which interact with corresponding knife strips in the coupling point 20, 21. This embodiment can be used in coupling points 20, 21 which have knife strips instead of knife clamps.

Claims (20)

1. Power supply network ( 10 ) comprising high-voltage ( 12 ), medium-voltage ( 14 ) and low-voltage lines ( 16 ) as well as local network transformer stations ( 15a , 15b , 15c ) which are connected to one another via the medium-voltage lines ( 14 ), wherein redundant low-voltage lines ( 19 ) or redundant medium-voltage lines ( 18 ) are provided in the area of a first local network transformer station ( 15a ), which, if necessary, for example in the event of a fault, can be connected via a coupling point ( 20 , 21 ) to redundant low-voltage lines ( 19 ) or to redundant medium-voltage lines ( 18 ) in the area of a second local network transformer station ( 15b ), characterized in that a device ( 24 ) is arranged in the coupling point ( 20 , 21 ), which allows high-frequency signals to pass and blocks low-frequency voltages (50 Hz). 2. Power supply network according to claim 1, characterized in that the coupling point ( 20 , 21 ) is designed to accommodate conventional NH or HH fuses. 3. Power supply network according to claim 1 or 2, characterized in that the device ( 24 ) has essentially the external design of a conventional NH or HH fuse. 4. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) has at least one capacitor ( 31 ), in particular a wound capacitor. 5. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) has a housing ( 27 ) made of porcelain. 6. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) has two male connectors ( 28 ) as connection contacts for reception in the coupling point ( 20 , 21 ). 7. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) comprises at least two capacitors ( 31 ) arranged in series or in parallel. 8. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) has a fuse ( 30 ), in particular in the order of magnitude between 50 and 250 mA. 9. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) has additional electronic components for influencing, in particular for attenuating, amplifying, suppressing interference, filtering, blocking or the like, signals. 10. Power supply network according to one of the preceding claims, characterized in that the impedance of the device ( 24 ) is adapted to the impedance of the local network transformer station ( 15 a, b, c) or of the power network ( 10 ). 11. Power supply network according to one of the preceding claims, characterized in that the device ( 24 ) is essentially completely encapsulated on the inside with a flame-retardant encapsulation ( 35 ), in particular according to UL 64 V0. 12. Device ( 24 ) for use in a coupling point ( 20 , 21 ) of a power supply network ( 10 ), wherein redundant low-voltage lines ( 19 ) or redundant medium-voltage lines ( 18 ) between two local network transformer stations ( 15a , 15b , 15c ) can be connected to one another via the coupling point ( 20 , 21 ) if necessary, for example in the event of a fault, characterized in that the device ( 24 ) comprises at least one capacitor ( 31 ) which blocks low-frequency voltages (50 Hz) and allows high-frequency signals to pass. 13. Device according to claim 12, characterized in that it has essentially the external design of a conventional NH or HH fuse. 14. Device according to claim 12 or 13, characterized in that the device ( 24 ) has a housing ( 27 ) made of porcelain. 15. Device according to one of the preceding claims 12 to 14, characterized in that the device ( 24 ) has two male connectors ( 28 ) as connection contacts for reception in the coupling point ( 20 , 21 ). 16. Device according to one of the preceding claims 12 to 15, characterized in that the device ( 24 ) has at least two capacitors ( 31 ) arranged in series or in parallel. 17. Device according to one of the preceding claims 12 to 16, characterized in that the device has a fuse ( 30 ), in particular in the order of magnitude between 50 and 250 mA. 18. Device according to one of the preceding claims 12 to 17, characterized in that the device ( 24 ) has additional electronic components for influencing, in particular for attenuating, amplifying, suppressing interference, filtering, blocking or the like, signals. 19. Device according to one of the preceding claims 12 to 18, characterized in that the impedance of the device ( 24 ) is adapted to the impedance of the local network transformer station ( 15 a, 15 b, 15 c) or of the power network ( 10 ). 20. Device according to one of the preceding claims 12 to 19, characterized in that the device ( 24 ) is essentially completely encapsulated on the inside with a flame-retardant encapsulation ( 35 ), in particular according to UL 64 V0.