EP1955082A1

EP1955082A1 - Method and apparatus for the remote reading of an energy meter

Info

Publication number: EP1955082A1
Application number: EP06841807A
Authority: EP
Inventors: Heikki SEPPÄ
Original assignee: VTT Technical Research Centre of Finland Ltd
Current assignee: VTT Technical Research Centre of Finland Ltd
Priority date: 2005-12-02
Filing date: 2006-11-28
Publication date: 2008-08-13
Also published as: CN101322036A; RU2008125046A; FI20051244A0; FI20051244L; WO2007063181A1; FI122463B

Abstract

The present publication describes a method and apparatus from the remote reading of energy meters. According to the method, several electrical appliances (1) are used to measure or control an electricity network, which electrical appliances (1, 4) are installed in the vicinity of each other, for example, in the same switch cabinet (6) or unit. According to the invention, in at least some of the electrical appliances (1) measurement information is recorded with the aid of RFID electronics (2) and forwarded through an antenna (3), or control information is received with the aid of the RFID electronics, the information transmitted from, or received in the electrical appliances (1) is transmitted with the aid of a collection device (4), which includes RFID reading electronics (8), as well as a telecommunications apparatus (10) from forwarding or receiving data, while the connection of the signal form the electrical appliances (1) to the collection device (4) is boosted with the aid of a conductor arrangement (5) located in the vicinity of the electrical appliances.

Description

Method and Apparatus for the Remote Reading of an Energy Meter

The present invention relates to a method, according to the preamble of Claim 1, for the remote reading of an energy meter.

The invention also relates to an apparatus for the remote reading of an energy meter.

The method disclosed in the invention combines a large group of kilowatt-hour meters with a collection meter for the collection of meter data over an RFID local-area network.

Devices and methods of this kind are used in condominiums or shopping centres, when there is a need for the rapid and automatic reading and forwarding of the energy consumption of several units, typically apartments, for billing.

According to the prior art, RFID modules are used to transfer information from an energy meter to a reading device. A solution as to how large groups of meters can be read remotely has not been disclosed.

Indeed, a drawback of the prior art has been how to bring energy meters economically into the sphere of automated remote reading. If a GSM apparatus is installed in each meter, the system will become extremely expensive and the meters will not be able to be installed in a metallic installation cabinet. If a GSM apparatus is installed outside the installation cabinet, the meter will have to be connected to the data-transfer equipment over a wired or wireless data network. A wireless network based on radio technology is expensive while a metallic installation cabinet will hinder the propagation of radio frequencies. While a wired connection will function, the system will have to be protectively separated, which will make a wired network difficult. An optical network is one solution worth considering.

The invention is intended to eliminate the defects of the state of the art disclosed above and for this purpose create an entirely new type of method and apparatus for the remote reading of energy meters.

The invention is based on using RFID technology to read electrical appliances, such as energy meters or relays, and improving the efficiency of the data transfer with the aid of a closed conductor arrangement, such as a conductor loop, located in the vicinity of the meters.

More specifically, the method according to the invention is characterized by what is stated in the characterizing portion of Claim 1.

The apparatus according to the invention is, in turn, characterized by what is stated in the characterizing portion of Claim 7.

Considerable advantages are gained with the aid of the invention.

The arrangement according to the invention permits a collection meter to easily read the measurement data of all the kilowatt-hour meters at even very frequent intervals, for example, of 1 second. Advantages of the system include ease of installation and the cheapness of RFID electronics. Further advantages include the fact that before or after installation the RFID property can be used as a wireless method to read the meter's data, for example, using a mobile telephone equipped with an RFID reader. Because RFID defines an individual address for each meter, the meters can be installed in cabinets in any order whatever and then afterwards a specific RFID address linked to some apartment-block address. Because there is also an RFID interface in the collection meter, the operation of the collection meter can be checked after installation, using a mobile telephone equipped with an RFID reader. The only additional work in the installation stage is the construction of a current loop around the meters. In new meter cabinets this can be done already at the factory. If 13.56-MHz technology is used, the meter can also be installed outside the meter room. Of course, this will require the conductor loop to be taken through the wall, or the meter to be installed on the wall, in such a way that there is an induction loop on the other side. The method permits meters, which are installed in apartment blocks, to be read using a collection meter, but meters, which are installed in sparsely populated areas to be read wirelessly, using a mobile telephone possessing RFID reading electronics. If GSM technology is retrofitted to these meters, a connection can be made to a meter simply, by utilizing RFID data transfer, without opening the meter. In addition, the existence of the RFID circuit in kilowatt-hour meters will considerably facilitate the logistics, start-up, and maintenance of the meters.

In the following, the invention is examined with the aid of examples and with reference to the accompanying drawing.

Figure 1 shows schematically one system according to the invention.

The applicant's earlier patent application FI20050501, which is confidential at the time of filing of the present application, discloses a method, in which the measurement and quality data of an energy meter can be transferred to the power company using a mobile telephone and an RFID protocol. The present invention presents a method, in which, by utilizing the same technology, it is possible to make a local sensor network, with the intention of automatically reading, for example, the meters of apartment blocks. An RFID local network of the type in question can, of course, also be used in other applications.

Figure 1 shows a typical situation in factories, shopping centres, apartment blocks, etc., where are large group of kilowatt-hour meters 1 are installed in a meter cabinet 6. Thus each of the meters measures at least the consumption of electrical energy, but typically information can also be obtained from these meters concerning current, voltage, the phase between them, and power, as both momentary and averaged values. The problem is how to bring these meters 1 economically into the sphere of automatic remote reading. If a GSM data-transfer apparatus is installed in each meter, the system will become extremely expensive and it will not be possible to install the meters in a metallic installation cabinet 6. If the GSM apparatus is installed outside, the meter will have to be connected to it using a wired or wireless data network. A wireless network based on radio technology is expensive and the metallic installation cabinet will hinder the propagation of the radio frequencies. A wired connection will function, but the system will have to be protectively separated, which will make the wired network difficult. An optical network is one solution worth considering.

In the solution of Figure 1, the local area network is made utilizing RFED technology. In the method, in each kilowatt-hour meter 1 there is an RFID circuit 2, or electronics simulating it, in the memory of which the measurement data are recorded. Thus the circuit 2 contains the memory necessary for recording the measurement values. An antenna 3 is connected to each RFDD circuit 2. The collection meter 4 located outside the switch cabinet contains not only electronics 2 simulating an RFED circuit, but also the electronics 8 and antenna 3 required for reading the RFED circuits. The reading electronics is thus used to read the measurement results recorded in the RFED circuits of the energy meters 1. A closed conductor loop 5, through which the data sent by the RFED circuits 2 of the energy meters 1 are transferred to the antenna 3 of the collection meter 4 and through it to the reading electronics 8 to be forwarded over a suitable data network 7, is brought close to the meters 1 being monitored and the collection meter 4.

The collection meter 4 can be only ah RFED unit equipped with an RFED reading circuit 8, in which there is a suitable telecommunications apparatus 10 for forwarding data over a data network 7. The telecommunications apparatus 10 can operate both over wires and wirelessly. Suitable forms of data-transfer are, for example, the GPRS, GSM, WLAN, RFED, and wired data-transfer protocols. However, in the preferred embodiment of the invention, the collection meter 4 is also an energy-consumption meter, which measures the sum of the energies of the meters 1 typically from a conductor, through which the sum current of the meters 1 travels.

Thanks to the invention, the collection meter 4 can use its reading device 8 to read the measurement data of all the kilowatt-hour meters 1 at even very frequent intervals, for example, of 1 second. When the meter field is being installed, the RFED circuit according to the invention defines an individual address for each meter 1. This means that the meters 1 can be installed in the cabinet 6 in any order whatever. After this, each apartment or other corresponding energy-billing unit can be connected by a program to the RFED address corresponding to the correct meter, which is typically the address of the apartment in the apartment block. Because there is also an RFED interface in the collection meter 4, the operation of the collection meter can also be ensured after installation, for example, using a mobile telephone equipped with an RFED reader. The only additional work in the installation stage is the construction of a closed conductor loop 5 around the meters 1 and 4. A current loop 5 can be made in new meter cabinets already in the manufacturing stage of the cabinet 6. If 13.56-MHz RFED technology is used, the collection meter 4 can also be installed outside the meter room. Of course, this will require the conductor loop 5 to be taken through the wall, or the meter to be installed on the wall, in such a way that the conductor loop 5 is on the other side of the wall.

The conductor loop 5 is thus a conductor ring, which is implemented, for example, by connecting any conductor whatever gaivanically to form a unified loop, a short- circuited ring. The cover of such a conductor is typically insulated. The conductor loop 5 is located close to the meters 1 and 4, but is not, however, in galvanic contact with them. A suitable distance from the conductor 5 for a sufficient connection to the meter 1 or 4 is 5 - 100 mm. The suitable distance naturally depends on, among other factors, the transmission power used and the type and geometry of the antenna. Figure 1 shows the placing of the meters 1 and 4 inside the conductor loop 5 as one preferred alternative of the invention. The location of the conductor loop 5 can, of course, be made in other ways relative to the meters 1 and 4, as long as a sufficient connection of the signal to the conductor loop 5 is taken care of by keeping the distance from the meters 1 and 4 to the conductor loop 5 sufficiently small.

At least initially, it is best to construct the system utilizing 13.56-MHz RFED technology, but if in the future 869-MHz or 2.45-GHz RFED reading electronics become available in mobile telephones, the system can also be built around their standards.

In the present application, the term electrical appliance refers, for instance, to a power- distribution network's energy meters, power, current, and voltage meters, as well as short and earth-circuit current meters, or electrical relays or switches. The term electrical appliance also refers, for example, to a domestic appliance equipped with an RFDD circuit, or to parts of it, which can forward information and receive control information.

The term conductor arrangement refers not only to the conductor loop shown in Figure 5, but also, for example, to the cabling of the power network connected to the electricity meters 1 and 4, used in a suitable manner through either an inductive or a capacitive connection, hi that case, a connection is arranged from each meter from its RFID circuit to the cabling of the power network, either capacitively by forming a sufficiently large capacitance between the RFID circuit and the electrical cabling, or inductively by forming a connection like a transformer between the RFED circuit of each meter and the cabling of the power network.

By using the above procedure, the connection of the power network need not be altered; instead the alterations are made during the connection of each meter, or in the manufacturing stage of the meter, by means of a suitable inductive or capacitive connection component 11.

By selecting the transmission-power levels suitably, the parallel meter fields (for example, in adjacent apartment blocks) will not interfere with each other.

Claims

Claims:

1. Method for the remote reading or control of electrical appliances (1), in which method several electrical appliances (1) are used to measure or control a power network, which electrical appliances (1, 4) are installed in the vicinity of each other, for example, in the same switch cabinet (6) or unit, characterized in that

- in at least some of the electrical appliances (1) measurement information is recorded with the aid of RFID electronics (2) and forwarded through an antenna (3), or control information is received with the aid of the RFID electronics (2),

- the information that is transmitted from, or received in the electrical appliance (1) is transmitted with the aid of such a collection device (4), which contains RFID reading electronics (8) and a telecommunications apparatus (10) for forwarding or receiving information, and - the connection of the signal from the electrical appliance (1) to the collection device (4) is boosted with the aid of a conductor arrangement (5) located in the vicinity of the electrical devices (1, 4).

2. Method according to Claim 1, characterized in that the conductor arrangement is a conductor loop (5).

3. Method according to Claim 2, characterized in that the conductor of the conductor loop (5) is equipped with electrical insulation that surrounds it and a conductor loop (5) is located at a distance of about 5 - 100 mm from each meter (1, 4).

4. Method according to Claim 1, characterized in that the electrical energy network connected (11) either capacitively or inductively to the meters (1, 4) is used at the conductor loop (5).

5. Method according to any of the above Claims, characterized in that the collection device (4) is a collection meter (4) measuring energy consumption.

6. Method according to Claim 5, characterized in that the collection meter (4) is used to measure the sum energy of the energy meters (1).

7. Apparatus for the remote reading or control of electrical appliances, which apparatus comprises several electrical appliances (1) installed in the vicinity of each other, for measuring or controlling the electrical quantities of various objects, characterized in that

- at least some of the electrical appliances (1) comprise RFID electronics (2) together with an antenna (3), in order to record and forward measurement information, or to receive control information and the apparatus comprises,

- a collection device (4), which contains RFID reading electronics (8) in order to receive and read measurement information transmitted by an electrical appliance (1), as well as a telecommunications apparatus (10) for forwarding or receiving information, and - a conductor arrangement (5) located in the vicinity of the electrical devices (1,

4), by means of which the signal from the connected electrical appliance (1) to the collection meter (4) is boosted.

8. Apparatus according to Claim 7, characterized in that the conductor arrangement is a conductor loop (5).

9. Apparatus according to Claim 8, characterized in that the conductor of the conductor loop (5) is equipped with electrical insulation that surrounds it and a conductor loop (5) is located at a distance of about 5 - 100 mm from each meter (1, 4).

10. Apparatus according to Claim 7, characterized in that the electrical energy network connected (11) either capacitively or inductively to the meters (1, 4) is used at the conductor loop (5).

11. Apparatus according to any of the above Claims, characterized in that the collection device (4) is a collection meter (4) measuring energy consumption.

12. Apparatus according to Claim 11, characterized in that the collection meter (4) is used to measure the sum energy of the energy meters (1).