System for the remote reading and control of electric energy consumption

DESCRIPTION

SYSTEM FOR REMOTE READING AND CONTROL OF ELECTRIC POWER CONSUMPTION

In particular, the invention applies to the field of power distribution to a plurality of users throughout the territory; but more generally it can also be applied to other services such as water and gas distribution or for district heating.

Such a system is known from US-A-5986574.

The invention meets the requirement - which has emerged worldwide for a number of years, especially in the most technically developed countries - to perform remote reading of electricity consumption and, if desired, to apply different rates to user billing, also in the case of home users. Such a problem has already been described, for example, in Italian Patent No. 1232195, filed on October 26, 1988 by the same Applicant, or in US-A-4803632.

This requirement has emerged and developed increasingly not only for economic reasons, but also because of the need for increased transparency and efficiency in contractual customer relationships in a market that is progressively becoming more liberalized.

Against this background, supported by technological developments in the field of component technology, a number of technical solutions, systems or methodologies have been proposed with the intention of solving the problems linked to this situation.

The approach that associates these different studies can be summarized in a network that uses various forms of communication to bring the peripheral points of the system (electricity meters at users' targets) in contact with a supervisory unit designed to implement procedures deemed useful continuously. , to achieve the desired objectives.

Said contact is obtained by direct communication between the supervision unit (generally a server with a high processing power) and the peripheral electricity meters, as described for example in WO-98/10299, or interposed in this pyramid by at least an intermediate hierarchical level as proposed in WO-98/10394. Examples of such proposals may also be found in other patents, for example EP-A2-0723358 or WO-99/46564.

However, the vast majority of these projects have very often remained at the stage of purely unrealistic attempts or laboratory achievements, while the few proposals that have evolved to the level of an industrial-type achievement have not achieved appreciable results in terms of dissemination and use. The reasons why such proposals have not found any large-scale application are that the industrial products obtained are not able to guarantee the required performance when applied to situations involving a very high number of user targets, as is generally the case here. of electricity consumption.

EP 1087211 A2 proposes the existence of the so-called virtual counters that are kept as software objects in a remote reading ZFA system. The counter pulses are transmitted over a network to the ZFA remote meter reading system where the counter data is stored. The load curve is processed, accessing this data and linking the load curves of the respective counters to tariff functions.

EP 0878892 A2 suggests an identical remote measurement procedure in which the meters are kept quite simple (page 3, line 5) and act as a simplified measuring station (page 3, line 11) that transmits basic data, defining the consumption. via a data network to a server assigned to its measurement station. The server processes the basic data for each metering station in a virtual tariff module (page 3, lines 40 to 42).

Accordingly, in these documents, the counter pulses, or so-called basic data, are transmitted via a data network to a centralized facility in which the virtual counters or virtual tariff modules are maintained.

The main object of the present invention is therefore to propose a system that allows, on the one hand, the remote acquisition of user targets data and, on the other hand, also the remote control of these targets, in order to meet the current requirements of all companies that - such as companies that distribute electricity, water, gas and others operate in the presence of a large number of user targets scattered throughout the territory. To give an indication of the meaning of the phrase a large number of user targets can be recalled that the company ENEL

Electricity) currently deals with around 30 million user targets.

Another object of the present invention is to propose a system capable of ensuring both regular and continuous operation and survivability also in the event of sudden interruptions of any kind of electrical power.

According to the present invention, said objects are achieved by a system which utilizes - in a well known manner - a single operation unit linked to user targets through a plurality of intermediate stations, the mentioned system having the characteristics pointed out in characterizing part of the claim 1.

Additional features and advantages of the present invention will be further apparent from the following detailed description of a preferred embodiment thereof, given merely by way of non-limiting example and partly illustrated in the accompanying drawing, the sole illustration of which shows a diagram of the structure of the system according to the invention. 0 This diagram represents, substantially, the organization of the Italian territory at the date of the application of this patent: it is intended to supervise and control about twenty-seven million electricity meters distributed throughout the territory. In any event, it is to be understood that this diagram is merely an example and should in no way be construed as limiting the present invention.

Thus, according to a first aspect of the present invention, such a large organization as illustrated in the drawing is obtained, on the one hand, by distributing the EC electricity meters according to units A1. . . Area An and connecting the counters of each unit to a respective common C-BT1 ... C-BTn concentrator. Each of said units Al ... An comprises a limited number of EC electricity meters; By the term limited is meant a relatively small number of EC counters, preferably between 50 and 300, determined by the vastness of the territory or area thus served, or other commercial factors linked to the territory under consideration;

on the other hand, distributing a plurality of said concentrators C-BT1. . . C-BTn throughout the territory being served, and then linking these hubs to a single central AMM server. By the term plurality is meant herein a greater number - by at least one, but also by two orders of magnitude - than the number of EC electricity meters of a unit, for example a number greater than 100000 concentrators, in the case to be 330000 concentrators illustrated.

According to a fundamental feature of the present invention, once such a network is created, the idea is not to concentrate processing capacity, namely system intelligence, only on the central AMM server - as was substantially done in the prior art - but distributing it among the three components mentioned above, namely the central AMM server, the C-BT1 concentrators. . . C-BTn, and the EC electricity meters. 0 The principle adopted for this distribution is that it provides a way for communication lines not to have to transmit a considerable amount of data to be processed, but only a small amount of data, which has already been at least partially processed.

Substantially, to enable a system involving such high numbers illustrated to function any locks, and functional performances such as those efficiently, without delay or without the present invention proposes to adopt the principle of distribution of processing power provided that it is reasonable from the point of view. economically as much as possible by the EC peripheral units and the C-BT1 concentrators. . . C-BTn, in order to make these units as autonomous as possible (even operating under autonomous conditions in the event of interruption of communication lines, or forgoing part of functional performance if necessary). Working in this way, we were able to load the communications systems as little as possible, actually transferring only the processed data instead of all the elementary data, and thus achieving some important results such as:

a simplification of the processing required for the central server;

a reduced communication load;

the availability of considerable amounts of usable bandwidth to support any additional services.

The principle that led to the realization of the present invention can be traced back to the fact that it reproduced a virtual (but totally faithful) image of the EC electricity meter within the C-BT concentrator. Virtually, it is as if in the concentrator there is an alias of the electricity meter, which is continuously updated by the concentrator in a predetermined manner, removing data from the actual electricity meter (which data is processed autonomously or following received controls). This image electricity meter is thus, in fact, actually and constantly available on the hub for transactions and data exchange, or for receiving controls and / or programs from the server.

This organization also allows the use of both the single EC electricity meter and the Al ... An area units formed by the C-BT single concentrator and the area unit EC electricity meters thus controlled. ; thus, without real-time server supervision but, for example, by periodically reading the concentrator data via a handheld terminal.

To obtain this result, another structural feature of the system thus formed lies in the fact that each of the CE meters incorporates, in addition to energy consumption measuring means, known substantially per se, also means for transforming the measured values ​​into data of at least one first processor for processing said measurement data, at least a first data memory and a first program memory, and a first means for bidirectional transmission towards the associated concentrator, said first processor output being connected to said first data memory and / or said first bidirectional transmission means, so as to at least temporarily store and / or respectively transmit the data, which has already undergone a first processing.

Likewise, each concentrator incorporates at least a second program memory, at least a second microprocessor for further processing said data processed by the counters, at least a second data memory for storing the data issued by said counters and / or said one. second microprocessor, and a second means for bi-directional transmission towards the central server, said second processor output being coupled to said second data memory and / or said second bidirectional transmission means, so as to at least temporarily store and / or respectively transmit said data subjected to further processing.

The connection for data transmission between the CE meters and the C-BT concentrators is preferably achieved through wave transmission systems using the same power supply conductors that connect the EC meters to the substations. low-voltage power supplies, eg the secondary substations, where the C-BT concentrators are located. In turn, the link between the C-BT1 concentrators ... C-BTn and the central AMM server are preferably obtained via a telephone network, either a specific or general purpose network. A very suitable telephone network for this purpose would be the GSM network, or any other public mobile telephone network, or any existing public wireless telephone network, eg, a satellite-based wireless telephone network. If such a network is employed, it is advantageous to establish telephone connections between the C-BT concentrator and the central AMM server on demand or according to a time that may be predefined or dependent on a working condition of the C-BT concentrator or AMM server. central.

If a default time is adopted, AMM or C-BT will attempt to establish a connection between AMM and C-BT at predetermined times during a day, week, or month, when it can be assumed that a certain amount of data or commands. requiring transmission, was collected and stored in the concentrator and / or AMM respectively. If the time is dependent on an AMM and / or C-BT operating condition, a telephone connection will be established as soon as a certain amount of data and / or commands requiring transmission has been collected or if certain alarm conditions have been met. detected and need to be reported without delay. In either case, after the data and / or commands have been transmitted, the connection is terminated.

With a system structure thus conceived, their respective features - which are also a feature of the present invention - end up strictly linked to the functions that each of the three of the system must perform.

the important measurements for being components

In particular, each electricity meter of the system according to the invention is sized such that said first processor incorporated therein is capable of performing at least the following functions: (1) acquisition of electricity consumption, (5) distribution of energy consumption by different price ranges, (12) estimation of intrusion attempts and control of an anti-fraud device, (25) transfer and maintenance of stored data at least during a voltage drop.

Likewise, each concentrator of the system according to the invention is sized such that the second processor incorporated therein is a dual mains master function), as regards those capable to perform, such as PLC communications network on the power supply line between the actual concentrator and the electricity meters and, respectively, of the TLC network node, for communications on the telephone line between the concentrator and the central server, at least the following additional functions: (11) performing an energy balance with respect to the single power supply cabin within which the concentrator is located, (14) Constant monitoring of the operating conditions of each electricity meter connected to it and an alarm signal if the meter self-diagnoses indicates a malfunction.

Finally, the server or central unit of the system according to the invention is sized so that its processor is capable of providing at least the following functions: (8) automatic control of shutdown, restart, suspend , late payments and contract variations, (10) selective shutdown of power supply due to electrical system requirements, and (26) unloading operating programs.

A more complete list - to be considered, however, as a non-limiting example - of the functions that the system according to the present invention is able to perform can be summarized in the following points, where an initial brief definition is followed. for a more detailed explanation of the associated function:

1. Measurement and acquisition of electricity consumption. The known types of electromechanical meters adopted in the present energy consumption system are capable of measuring only one type of active or reactive electrical energy consumption; If both measures are necessary, it is therefore necessary to install two separate electricity meters. 0 The electronic electricity meter according to the present invention is instead capable of simultaneously measuring active energy consumption and reactive energy consumption.

2. Accuracy rating. According to the standards, electricity meters measure in class 1 for active energy and class 2 for reactive energy.

3 Acquisition and registration of the consumption profile. For each user it is possible to detect the billing curve, with a programmable integration period, particularly in the range of 1 minute to 1 hour. Thanks to the electricity meter's processing capacity, it is possible to calculate the progress of consecutive time intervals and, for each of them, to memorize the energy consumption within it.

4 Measurement and recording of average and peak energy. Electromechanical meters commonly used in the energy consumption system are only capable of measuring one type of energy, active or reactive; If both measures are required, it is therefore necessary to install two electricity meters as mentioned above for electricity consumption. 0 The electronic electricity meter of the present invention is instead capable of simultaneously measuring active energy and reactive energy.

5 Distribution of electricity consumption at different price ranges. Thanks to its processing capacity, the electricity meter is able to set a table of different timeframes within a day, thus allowing each of them to establish a respective cost value for the electricity consumed. 0 The electricity meter is thus able to integrate the consumption in relation to the cost table and to store the total consumption of each period during the billing period. In addition, said cost schedule can be programmed not only on the basis of time profiles but also on the basis of energy thresholds.

6 Control of multiple billing periods. At least two billing periods (present and previous) can be controlled, also at varying intervals.

7 Control of two electricity supply contracts. In the power range up to 35 kW, it is possible to control two power supply contracts, namely one existing and one to be applied in the future. The electricity meter can be programmed to automatically switch contracts - from present to future contracts - upon a certain date.

8 Control of power off and on operations. These transactions may be carried out automatically in respect of interruption, suspension of late payments and contract variations. Due to its processing capability, the electricity meter performs these operations based on remote controls (from the central server or the respective concentrator) through the PLC network. Thus, it is not necessary for an operator to physically travel to the place where the electricity meter is installed.

9 Possibility to work on prepayment conditions. The electricity meter may be programmed to compare the amount of electricity used with a predetermined limit (possibly modifiable by an external control) corresponding to an advance payment; Once the mentioned limit has been exceeded, the power supply is automatically switched off and suspended.

10 Selective cutting for electrical system requirements. Power outage or shutdown may be required, usually at the local level, in the event of a risk of sudden power outages or temporary overloads. This function is not implemented in a broadcast mode, but is instead specifically addressed to each of the electricity meters. From the center (central server or concentrator) a control can be sent to the electricity meters via PLC, for example to modify the maximum available power on the real meter, with a temporary effect, ie without changing the contract power supply; This allows a reduction in the overall required cab power.

11 Execution of an energy balance. At the level of a single cabin, or single concentrator, it is possible to sum the measurements of the energy consumption extracted from the individual electricity meters dependent on that cabin. This sum periodically compared to the value of the total electrical current withdrawn, or the value of the average electrical current - provides a useful indication for detecting any non-standard electrical subtractions and thus also any unauthorized subtractions.

12 Anti-fraud / intrusion function. At the level of each electricity meter, a device is provided to perform this specific function, which is thus able to eliminate the requirement to use seals and to periodically check the integrity of these seals. The change of power, available by contract, does not require - as mentioned - the opening of the electricity meter in order to adjust the shunt; It was thus possible to realize the electricity meter as a single sealed block structure containing all metering functions, contract control, power line open / close circuit control. In order to verify any possible attempts to open the sealed structure on the electricity meter, an electromechanical device which produces an alarm signal in the system network has thus been incorporated and said alarm signal can only be removed by adopting a procedure available to the users. operators.

13 Measure and record quality of service parameters. The microprocessor incorporated in each electricity meter is capable of checking and storing power supply interruptions and voltage variations (voltage deviation from the nominal value provided for in the electricity supply contract). Based on these data, it is possible to determine the quality of service parameters at the level of each of the distribution points of the electricity to be supplied.

14 Constant monitoring of operating conditions. The microprocessor incorporated in each electricity meter is capable of periodically checking (self-diagnosing) the condition of the various hardware components of said meter and the congruence of the data stored in memory. In the event of any malfunctions, it is possible to signal the same with appropriate service words (which are then read by the central system), and initiate recovery procedures immediately.

15 Possibility of bi-directional transmission of information. The system according to the invention allows not only to perform operations directly linked to the provision of the service for which the system was designed, but also to send to the electricity meter and to receive from it other types of information (information provider service). 0 The electricity meter can display this information on its own display unit, or transfer it to other devices connected to the user's power line downstream of the electricity meter, or even extract it himself; These devices are interconnected directly with the electricity meter via PLC, or via a bridge device acting as an intermediate link and communicating directly with the electricity meter via PLC. This enables other subjects to use the system according to the invention as a remote control system allowing us to connect to our own devices at the user's site.

16 Management of a calendar clock. Having attributed to the meter the calculation of consumptions as a function of the price scale, the meter mentioned requires an accurate time reference (± 30 sec / month); This is achieved by means of a local electronic circuitry (RealTimeClock), the status of which can be checked and synchronized remotely (via external controls, via PLC or ZVEI optical port) and corrected if necessary in case of excessive variations.

17 Viewable data set. In the local counter display (eg 16x1 alphanumeric + icons), a whole series of data can be programmed. The presence of electronic components provides additional functions such as presenting the user with local consumption and cost data, generic messages or messages providing information about the service, or indicating the functional status of the meter to service personnel (diagnostics). ).

18 Opening of the power circuit. A modular element equipped with a suitable opening element that can be opened by remote control is integrated in the counter. A single housing houses the electronics capable of performing the measurement functions described so far, and the electromechanical components capable of opening / closing the power line. In this way, the electromechanical components, in addition to operating autonomously at full power, can also be driven at the request of the central unit or in the presence of local conditions detected by the electronic part (eg when the contract expires).

19 Quick meter installation. Having the need to replace a large number of devices at user locations within a short period of time, the invention provides a two-part counter group, namely having a base wedge and a control and management body, the two parts being connected by pliers. connection and bayonet joint.

20 Ability to local interconnect with external devices. The PLC communication system requires the availability of complex hardware and software. In order to ensure the accessibility of data contained in concentrators and counters even by simple devices (eg portable PCs) available to a user, and the availability of a second communication line replacing the network should it be interrupted; A ZVEI optical port is also associated with the counter. This port only requires that the external device has a simple RS-232 serial port (available on almost all PCs).

21 Security / protection of PLC communication. Data transferred from the hub to the counters or from the hub to the central server has varying degrees of privacy. For those not considered strongly reserved, the protection mechanisms implemented by the functions that manage the PLC's communication protocol, capable of guaranteeing message delivery, are sufficient. For critical data, an additional mechanism has been added - e. g., based on an authentication key - at the message interpretation and management procedure level, able to guarantee the non-modification and / or readability of such messages by entities outside the service.

22 Automatic recognition of meter installation. This function must be present for two reasons: one is technical, related to the PLC's communication mechanisms, the other is fiscal, in order to detect possible fraud by users.

23 Possibility to reach distant counters. The PLC's communication method uses a physical medium (power line) that does not guarantee homogeneous signal conduction at all points of the network, which is why counters may not be reachable by the concentrator. Therefore, the hub may require one or more counters (who can see the unreachable counter) to act as bridges, forwarding the message to the unreachable counter. It is, in fact, a retry mechanism that solves the problem of reachability over the network.

24 Automatic recognition of the repeat path. When informed of the presence of a new counter, the concentrator verifies that it can be reached. If the counter is not reachable, the concentrator attempts to detect one or more different counters that can see the unreachable counter directly. These counters are detected, the detection parameters are memorized, and are subsequently used as an intermediate bridge.

25 Data maintenance under voltage breakdown conditions. Replacing the mechanical devices that record consumption (numbered wheels) with electronic components (volatile memories) would result in the loss of consumption data if the power supply company were interrupted. In order to avoid this, a non-volatile memory, preferably an electric iron RAM (FRAM), has been used in the system to ensure data maintenance over the life of the electricity meter (15 years).

26 Download management programs. In order to ensure the correct development and / or maintenance of the functions performed by the programs installed on the system devices, it is possible to modify said programs without interrupting the fundamental activities of the said devices and without having to move to where they are located; The activity is performed using the PLC communication mechanisms used by the control center to manage the devices.

27 Line switch open detection. When one of the power supply cabin output lines - where the concentrator is located - is out of service due to the opening of the line protection switch, the concentrator, based on the inability to communicate with all counters supplied by that line, indicates to the central server an out of line alarm condition.

It should be understood, however, that this list is not intended to be limiting of the scope of the invention. This description is intended to highlight, by way of example, how the main functions are distributed among the three components (counters, concentrators and central unit) of the system according to the invention, considering the functional capacities of these three components, as further specified. thereafter and in the claims.

In other words, in order to achieve the basic idea of ​​the present invention, synthetically indicated as intelligence assignment, it is preferred that:

(a) accountants are assigned at least one of the functions indicated in paragraphs 1), 5), 12) and 25); but also preferably the functions indicated in numbers 2), 3), 4), 6), 7), 12), 13), 16), 17), 18),

19), 20) and 25) are executed on the counters;

(b) the accountants are able to manage, together with the concentrators and the server, at least one of the functions indicated in paragraphs 9), 14), 15), 21), 22),

23) and 26);

(c) concentrators are assigned at least one of the functions indicated in paragraphs 11) and 14), as well as those of the PLC network master and TLC network node, but preferably also the functions indicated in numbers

20) and 24) are performed on the concentrators;

(d) the central server is assigned at least one or more of the functions listed in paragraphs 8), 10), 17) and

26), but that the function indicated in paragraphs 9) and 21) is also preferably performed on the central server, such as, of course, the TLC network master function, and other potential billing and management functions ( not related to this patent application).

In other words, system intelligence is distributed among the central unit, concentrators and counters so that each of these three system elements has its own processing capacity, albeit limited in counters but sufficiently relevant way to reduce data transmission requirements through bidirectional transmission;

these requirements are limited, on the one hand, by reducing the amount of data transmitted or, on the other hand, by delaying their transmission for times when transmission lines are less busy.