Electrical mains cable

Abstract

In order to enable an electrical device (1), which has a panel connector (10) for connection to a mains supply (30), to be identified by a reader (370) of a smart socket (30) of the mains supply (30), a mains cable (2) is proposed that has an antenna (217, 227) on each of its two connectors (21, 22), wherein these two antennas (217, 227) are interconnected by an information line (27) of the mains cable (2). An RFID tag (17) is mounted in the panel connector (10) of the electrical device (1), the information of the RFID tag is read by the first antenna (217) of the mains cable (2) and transmitted via the information line (27) to the second antenna (227) of the mains cable, and from there to a reader antenna (37) arranged in or on the socket (30). At least the second antenna (227) and the reader antenna (37) are preferably near-field antennas, in order to prevent crosstalk to possible neighbouring sockets.

Description

[0001] Title: Electrical power cable

[0002] Description

[0003] The invention is based on an electrical power cable according to the preamble of independent claim 1.

[0004] Such power cables are required for power supply, i.e. for connecting electrical devices to a power grid, i.e. to an electrical power distribution system. Such a power cable usually has a first end and a second end. At said first end, a first plug connector is arranged for connecting the power cable on the device side to a built-in plug connector usually built into a housing of the respective electrical device, wherein this built-in connector is preferably designed as a cold appliance plug or at least has a cold appliance plug. At the second end of the power cable, a second plug connector is arranged for connecting the power cable on the mains side to a socket of the electrical power distribution system.

[0005] For example, the first connector of the power cable may be a so-called IEC connector, which is designed as a IEC socket for contact protection. The second connector of the power cable may be a Schuko (protective contact) plug. Accordingly, the socket may be a Schuko socket. Furthermore, the power cable may be a IEC connection cable.

[0006] The first and second connectors of the power cable each have a plurality of, in particular two or three, plug contacts. In particular, the plug contacts of the first connector are designed as pin contacts and the plug contacts of the second connector are designed as socket contacts. Each of the plug contacts of the first connector is electrically connected to one of the plug contacts of the second connector via an electrically conductive wire, e.g. a stranded wire, of the power cable, either for the purpose of electrical energy transmission or for PE (“Protective Earth”) connection. These wires are usually each surrounded by insulation. In addition, the aforementioned electrical conductors are surrounded by a common sheath of the power cable, which has at least one further insulation and may optionally also have a shielding foil and / or a shielding braid embedded therein.

[0007] State of the art

[0008] Intelligent sockets, also called "smart sockets," are known in the prior art, for example from document DE 10 2015 009 361 A1. These intelligent sockets are typically used between an electrical supply network, preferably a 220V AC network, and an electrical device whose plug connector is connected to a socket receptacle of an adapter plug.

[0009] Smart plugs are typically equipped with a switching element embodied as a microcontroller or processor and a data transmission unit, also called a communications module. The switching element can be used to turn the electrical device connected to the plug on or off. In some embodiments, the processor or controller is also designed to determine the electrical power consumed by the connected device.

[0010] Knowing which device or device type is in the socket insert is necessary to apply the appropriate control logic for the device and, if necessary, also display it. To do this, the device type is manually selected, for example, from a provided list, and configured on the respective socket.

[0011] Another approach to setting the device type relies on the data transmission unit integrated into the smart socket transmitting the energy consumption information to an external data processing device. From this, the characteristics of the respective energy consumption of the plugged-in device are processed on data processing devices connected to the smart socket and used to determine the device type of the plugged-in device.

[0012] However, the procedures described above are error-prone and require additional hardware or software effort.

[0013] Based on the aforementioned prior art, the document mentioned at the outset has set itself the task of specifying a device whose intelligent socket enables automated detection of an electrical device, in particular its device type, accommodated in the socket insert of the socket in a simple manner.

[0014] As a solution, the document proposes a device for automatically detecting an electrical device connected to a smart socket. The smart socket has a socket insert arranged in the socket for receiving a connector of the electrical device, an electrical connection of the socket to an electrical supply network, for example, a 220V AC network, at least one switching element via which the electrical device connected to the socket insert can be switched on or off, and a communications module integrated into the socket that interacts with a remote data processing device via another connection.

[0015] According to the teaching of this publication, the above-mentioned problem is to be solved by the following features:

[0016] The connector of the electrical device plugged into the socket insert is equipped with a radio tag that stores data regarding the device type of the electrical device to be connected to the smart socket. The radio tag can be implemented as an RFID tag or NFC tag, for example.

[0017] The smart socket is equipped with a reader, for example, an RFID or preferably an NFC tag reader, which enables communication between the radio tag and the reader when the plug-in connector is inserted. The reader contactlessly captures a signal containing modeled data regarding the device type of the electrical device plugged into the socket from the radio tag and transmits it to a remote data processing device. This modeled data can, for example, be a unique ID number of the device plugged into the socket insert and / or data packets relating to the plugged-in device.

[0018] Furthermore, a preferred development is disclosed in which the intelligent socket is configured to transmit information on the energy consumption of the connected electrical device via the communication module to the remote central data processing device. A disadvantage of this prior art is that many electrical devices do not have their own power cable permanently connected to the device with a plug connector, e.g., a Schuko plug, arranged at the end. Instead, many devices are equipped with a built-in plug connector, e.g., a built-in

[0019] A cold appliance plug intended to be used with a matching mains cable, e.g. a cold appliance connection cable, the mains cable being equipped with a first connector at a first end and with a second connector at the other end.

[0020] Such devices are inherently unsuitable for identifying themselves to a smart socket using a wireless tag, such as an RFID tag or NFC tag, located in or on their second connector, especially their Schuko plug. Finally, these power cables, which are preferably the aforementioned IEC power cords, are inherently interchangeable, meaning they can be interchanged, so the correct assignment of the respective tag to the corresponding device cannot be guaranteed.

[0021] Task

[0022] The object of the invention is to enable identification of an electrical device which has a built-in plug connector for connection to a power grid by means of an electrical power cable, by means of a reader which has a reader antenna which is arranged in or on a socket of the power grid of an electrical energy distribution system. In particular, this socket can be a so-called intelligent socket (“smart socket”). The built-in plug connector of the electrical device can preferably be designed as a cold appliance plug or at least have such a cold appliance plug, so that the built-in plug connector is a cold appliance plug. The power grid-side socket of the energy distribution system can preferably be designed as a so-called Schuko socket (“protective contact socket”).

[0023] The problem is solved by the subject matter of independent claim 1.

[0024] An electrical power cable is used to connect an electrical device to an electrical power distribution system.

[0025] The power cable has a first connector at its first end for plugging into a built-in connector of the electrical device. In particular, this first connector of the power cable may be a IEC socket plug for contact protection.

[0026] Furthermore, the power cable has a second connector at its second end for plugging into a so-called "smart socket" of the power distribution system. In particular, this second connector can be a Schuko plug ("safety contact plug"), and the aforementioned socket - as already mentioned - a Schuko socket ("safety contact socket").

[0027] The smart socket can be characterized in particular by being equipped with at least one switching element (“switch”) embodied as a microcontroller or processor and a data transmission unit, also called a communications module. Furthermore, the smart socket can preferably also include an electricity meter.

[0028] Each of the two connectors of the power cable has at least two electrical plug contacts as power transmission contacts for electrical energy transmission, wherein each of the two plug contacts of the first connector is electrically connected to a plug contact of the second connector via an electrically conductive wire (e.g., commonly referred to in technical jargon as the so-called "phase" and "neutral") of the power cable. Preferably, each of the two connectors can also have at least one PE ("protective earth") contact, wherein these PE contacts are connected to one another via a PE wire ("grounding wire") of the power cable.

[0029] According to the invention, the power cable additionally has at least one further electrical line, namely an identification line, for transmitting identification information. At its first end, the information line has a first antenna arranged in or on the first connector of the power cable. This first antenna serves to wirelessly receive said identification information from a radio tag arranged in or on the built-in connector of the device. Furthermore, at its second end, the identification line has a second antenna arranged in or on the second connector of the power cable for wirelessly transmitting the identification information to a reader antenna of a reader arranged in or on the intelligent socket.

[0030] Advantageous embodiments of the invention are specified in the subclaims and the following description.

[0031] The invention has the advantage that it is also possible to identify electrical devices that do not have a permanently connected power supply cable, but instead have a connection, for example the said built-in connector, for a separate power cable.

[0032] A further advantage is that interchanging several such power cables does not affect the correct identification of the electrical device, since the identification of the radio tag, e.g., the RFID tag or NFS tag, attached in or on the electrical device's built-in connector is received by the first antenna of the power cable, transmitted via the power cable's identification line to the second antenna of the power cable, and sent from the second antenna of the power cable to the reader antenna of the reader located in or on the smart socket. Such power cables are therefore interchangeable.

[0033] In an advantageous embodiment, at least the second antenna of the power cable and the reader antenna are each near-field antennas, which are characterized in that they have a joint range of only a few cm (centimeters) in the described use, for example a joint range of less than 10 cm, in particular less than 5 cm, preferably less than 4 cm and particularly preferably less than 3 cm, for example 2.5 cm and less.

[0034] A further advantage is that even several such devices can be uniquely identified, thus eliminating the risk of confusion if the power outlets are located next to each other and the radio signals between the respective second antennas and reader antennas do not interfere with each other, thus preventing crosstalk to the reader antenna of the adjacent outlet. The cables transport the identification signal from the radio tag of the respective device to the reader antenna of the respective outlet, so that the electrical device can be located several meters away from the corresponding outlet and correct identification is still guaranteed without interference via the near-field antennas. The electrical devices are usually located far enough apart from each other.In a preferred embodiment, the radio tag attached to the respective electrical device also has a near-field antenna, so that crosstalk is advantageously eliminated at this location as well. In a preferred embodiment, at least the first and / or second antenna of the power cable can be active, i.e., have electrical amplification.

[0035] This has the advantage of ensuring particularly reliable signal transmission. In particular, even longer power cable lengths of more than 5 m (meters), especially more than 10 m, preferably more than 15 m, and even 20 m and more can be ensured with high signal integrity.

[0036] In a preferred embodiment, the identification line can be used bidirectionally. This enables more complex identification processes between the radio tag and the reader.

[0037] In an advantageous embodiment, the identification line can be implemented as an additional electrical wire pair, e.g., a stranded pair, within the power cable. This allows for a comparatively large conductor cross-section and enables particularly good transmission properties of the identification line. The identification line is then particularly well protected from environmental influences. This technology is therefore suitable for long cable lengths and / or use in so-called "harsh environments," i.e., exposed to dirt, moisture, extreme heat or cold, in areas with aggressive chemicals, etc.

[0038] In an alternative embodiment, the identification line can be applied as an electrically conductive coating to the insulation of the power cable sheath with comparatively little manufacturing effort, for example, using an MID process or any other coating process. This is suitable for relatively short power cables in less harsh environments. Furthermore, retrofitting of existing systems is possible. The identification line embodied as an electrical coating can, for example, consist of two separate, electrically conductive tracks. In a preferred embodiment, the first and / or second antenna can be constructed three-dimensionally. This has the advantage that—depending on the circumstances—a particularly well-adapted and thus particularly effective coupling can be achieved.

[0039] In a further preferred embodiment, the first and / or second antenna can be incorporated into the respective first and / or second connector of the power cable, e.g., by overmolding. This has the advantage of protecting them from environmental influences. Such power cables are ideal for use in the aforementioned harsh environments.

[0040] Alternatively, the first and / or second antennas can also be attached externally to the first and / or second connectors, e.g., by gluing or using an MID process. This reduces manufacturing costs and enables retrofitting of existing systems.

[0041] The invention is particularly advantageous in industrial plants, office buildings, hospitals, and other safety-relevant areas. Finally, the invention can ensure compliance with safety-relevant standards (e.g., DGUV V3) even for commercially available electrical devices that do not have attached power cables, using smart sockets. For example, the socket in question can simply be switched off if the connected device does not have the required certification. Furthermore, overloading can be prevented as a precautionary measure and without negative consequences for other consumers by simply switching off the smart socket of the last connected device (or a device with a lower priority level), without affecting the other devices supplied by the same circuit.All these possibilities can be advantageously realized by the present invention also for electrical devices that do not have an attached power cable, but instead have a built-in connector, e.g. a cold appliance plug, for their power supply.

[0042] The invention therefore advantageously serves to increase the level of security in the aforementioned areas.

[0043] Example

[0044] An embodiment of the invention is illustrated in the drawings and explained in more detail below. They show:

[0045] Fig. 1 is a schematic representation of a first power cable;

[0046] Fig. 2 shows a system comprising an alternatively designed second power cable, an electrical device and a power supply with an intelligent socket.

[0047] Some of the figures contain simplified, schematic representations. Identical reference symbols are used for similar, but possibly not identical, elements. Different views of the same elements may be scaled differently. Directional references such as "left," "right," "top," and "bottom" are to be understood with reference to the respective figure and may vary in the individual illustrations relative to the object depicted.

[0048] Fig. 1 shows a schematic representation of a first power cable 2. The first power cable 2 is a cold appliance connection cable. The first power cable 2 has a first plug connector 21 (shown on the right in the drawing), namely a cold appliance plug connector, which is designed as a socket plug, i.e. as a cold appliance socket plug, for contact protection. This first plug connector 21 is intended for plugging into a built-in plug connector 10, namely a cold appliance built-in plug, installed in a housing of an electrical device 1. Furthermore, the first power cable 2 has a second plug connector 22, shown on the left in the drawing, which is designed as a Schuko plug and is intended for plugging into an intelligent socket 30.The first connector 21 has two socket contacts 211, 212, not shown in this illustration but shown in the following illustration, as energy transmission contacts, namely a first 211 and a second 212 socket contact. On the second connector 22, the two pin contacts 221, 222 are shown as electrical energy transmission contacts. However, for reasons of clarity, the PE connections of both connectors 21, 22 and the PE wire connecting them have been omitted here. Furthermore, for reasons of clarity, the first wire pair intended for electrical energy transmission, consisting of a first wire 201 (“phase”) and a second wire 202 (“neutral wire”), which connects the socket contacts 211, 212 to the pin contacts 221, 222 for electrical energy transmission, has also been omitted.

[0049] However, an identification line 27 is shown here, which is designed as a second wire pair and runs inside the cable, i.e., is surrounded by a sheath of the first power cable 2. The identification line 27 connects a first antenna 217, which is arranged on the first connector 21, to a second antenna 227, which is arranged on the second connector 22. For this purpose, a first 271 and a second 272 wire of the identification line 27 electrically connect the two ends of the two antennas 217, 227 to each other.

[0050] Figure 2 shows a somewhat more comprehensive arrangement. The drawing on the left shows electrical device 1, which is to be connected to the power grid 3 (electrical power distribution).

[0051] This electrical device 1 has, in addition to an unspecified

[0052] Consumer 16 has a built-in connector 10 that has a cold appliance plug 11. Furthermore, a radio label 17, designed as an NFC tag, is attached to the built-in connector 10.

[0053] The power grid 3 comprises a power supplier access point 300 and the intelligent socket 30 electrically connected to it. In addition to electrical plug contacts (not designated in more detail for reasons of clarity, which are designed as sockets for protection against accidental contact), this intelligent socket 30 has an electrically connected switch 33 and a connected current measuring device 35 ("ammeter"), which are connected on the primary side to the power supplier access point 300. Furthermore, the intelligent socket 30 has a network interface 34 as a data transmission unit and a reader 370, namely an NFC reader 370 and a reader antenna 37 connected to it.

[0054] The electrical device 1 is connected to the intelligent socket 30 via an alternative, second power cable 2, ie the first connector 21 of the second power cable 2 is plugged into the built-in connector 10 of the electrical device 1 and the second connector 22 of the second power cable 2 is plugged into the intelligent socket 30.

[0055] In the second power cable 2, this illustration shows the first wire pair 20 intended for electrical energy transmission, consisting of a first 201 and a second 202 wire. Its two wires 201, 202 ("phase", "neutral") run within the sheathing of the cable 2. The antennas 217, 227 of the first 21 and second 22 connectors, respectively, as well as the identification line 27 connecting them, are shown symbolically here. The antennas 217, 227 are applied to the respective connectors 21, 22 using an M ID process. The identification line 27 is also applied to the sheathing of the second power cable 2 from the outside using an M ID process. By means of such a first or second (alternative) power cable 2, it is possible not only to supply electrical devices 1, which have a built-in connector 10 for the power supply, with power, but also to identify them via the intelligent socket 30.This allows such devices 1 to be authorized for use in particularly safety-relevant areas. Furthermore, a maximum power consumption can also be assigned to the devices 1, either by measurement, e.g., via the power meter, or by their specification obtained via the data interface, e.g., from the Internet 4. Thus, a single socket 30 in the power grid can be switched off in a targeted and timely manner to prevent an overall overload, without affecting other sockets in the same power distribution system.

[0056] List of reference symbols

[0057] 1 electrical device

[0058] 10 built-in connectors

[0059] 11 IEC connectors

[0060] 16 consumers

[0061] 17 Radio Frequency Identification (NFC)

[0062] 2 first, second (alternative) electrical power cable

[0063] 20 first pair of wires (for electrical energy transmission)

[0064] 201 first wire (“phase”)

[0065] 202 second wire (“neutral wire”)

[0066] 21 first connector

[0067] 211 first socket contact

[0068] 212 second socket contact

[0069] 217 first antenna

[0070] 22 second connector

[0071] 221 first pin contact

[0072] 222 second pin contact

[0073] 227 second antenna

[0074] 27 Identification line (second pair of wires)

[0075] 271 first wire of the identification line

[0076] 272 second wire of the identification line

[0077] 3 Electrical energy distribution / power grid

[0078] 30 smart sockets

[0079] 300 electricity supplier access

[0080] 33 switches

[0081] 34 Network interface / data transmission unit 35 Current measuring device

[0082] 37 Reader antenna

[0083] 370 Reader 4 Internet

Claims

Claims: An electrical power cable (2) for connecting an electrical device (1) to an electrical power distribution system (3), wherein the power cable (2) has at its first end a first connector (21) for plugging into a built-in connector (10) of the electrical device (1) and wherein the power cable (2) has at its second end a second connector (22) for plugging into a smart socket (30) of the power distribution system (3), wherein each of the two connectors (21, 22) of the power cable (2) has at least two electrical plug contacts (211, 212, 221, 222) as power transmission contacts, wherein each of the two plug contacts (211, 212) of the first connector (21) is connected to a plug contact (221, 222) of the second connector (22) via an electrically conductive conductor (201, 202) of the power cable (2). is electrically conductively connected, characterized in thatthat the power cord (2) additionally has at least one further electrical conductor as an identification conductor (27) for transmitting identification information, wherein the identification conductor (27) has at its first end a first antenna (217) arranged in or on the first connector (21) for wirelessly receiving said identification information from a radio tag (17) arranged in or on the built-in connector (10) of the electrical device (1), and wherein the identification conductor (27) has at its second end a second antenna (227) arranged in or on the second connector (22) for wirelessly transmitting the identification information to a reader antenna (37) of a reader (370) arranged in or on the smart socket (30).

2. Electrical power cable (2) according to claim 1 , characterized in that the second antenna (227) of the power cable (2) and the reader antenna (37) are each near field antennas.

3. Electrical power cable (2) according to one of the preceding claims, characterized in that the first (217) and / or the second (227) antenna of the power cable (2) is active.

4. Electrical power cable (2) according to one of the preceding claims, characterized in that the identification line (27) is bidirectional.

5. Electrical power cable (2) according to one of the preceding claims, characterized in that the identification line (27) is designed as a further electrical pair of conductors (271 , 272) within the power cable (2).

6. Electrical power cable (2) according to one of claims 1 to 4, characterized in that the identification line (27) is applied as an electrically conductive coating to an insulation of a sheathing of the power cable (2).

7. Electrical power cable (2) according to one of the preceding claims, characterized in that the first (217) and / or the second (227) antenna has a three-dimensional shape.

8. Electrical power cable (2) according to one of the preceding claims, characterized in that the first (217) and / or the second (227) antenna are inserted into the respective connectors (21 , 22), i.e. into the first (21) and / or the second connector (22) of the power cable, (2). An electrical power cable (2) according to claim 8, characterized in that the first (217) and / or second (227) antenna is injection-molded into the first (21) and second (22) connectors, respectively. An electrical power cable (2) according to any one of claims 1 to 7, characterized in that the first (217) and / or second (227) antenna is applied externally to the first (21) and / or second (22) connectors by adhesive bonding or by an MID process.

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