EA003601B1 - Electrical energy meter - Google Patents

Abstract

1. An electrical energy meter cutting off power supply after a preset (pre-paid) amount has been used up, comprising: -sensors of the electric current parameters changing in time and relays for disconnection the customers from the power network, -reader of information off the smart card about the sum of pre-payment made by the customer for use of electricity, -display for outputting information, -interface to transmit information to external device upon request, -processor to integrate said functional elements of the meter into a system to calculate the amount of expended electricity, pre-payments made by the customers and available credit of each customer, and to control said functional elements of the meter, characterized in that -contains additionally (n-1) sensors of the electric current parameters and (n-1) relays for disconnection the customers from the power network, -multiplexer connected to the outputs of sensors of the current parameters, the output of said multiplexer being coupled with processor to transmit to said processor information about the parameters of the current used by each customer as a function of time, -command unit connected to said processor's outputs to transmit processor's command to the relay of corresponding customer for disconnecting said customer from the power network if the amount of electricity used up by said customer reaches the preset value. - reader of information being made with the possibilities of fixing from smart card of each customer of pre-payments made by the customers. 2. The meter, according to Claim 1, wherein -said sensor of the current parameters is equipped with current transformer, and analog-to-digital -converter is switched on between said multiplexer and said processor, said converter is switched on at intervals of time sufficient to ensure the preset class of accuracy in recording current parameters in time. 3. The meter according to Claim 1, wherein -said sensor of the current parameters is equipped with current transformer, linear pulser and pulse counter, and -said pulse counter is coupled with said processor via multiplexer. 4. The meter according to Claim 1, wherein -said sensor of the current parameters is equipped with current shunt coupled with said linear pulser, -the output of said linear pulser is coupled with said pulse counter via optical circuit separator, -output of said pulse counter is coupled with said processor via said multiplexer, with greater operation safety ensured. 5. The meter according to Claim 1, wherein -functional elements are installed in a single cabinet, -said cabinet is connected by separate cables to the customer's premises controlled individually with prevention of the attempts of unauthorized connections to the power network and/or tampering with the meter's components. 6. The meter according to Claim 1 wherein, in the case of customers being spaced at a substantial distance from each other -is made with placement in the central cabinet and personal cabinets for each customer, -whereas the components serving all customers and transmitter receiver are installed in the central cabinet, and -said personal cabinets are located close to each customer in a place difficult to access, while said personal cabinets house said sensors of current parameters, relays and devices to ensure coupling between personal and central cabinets. 7. The meter according to Claim 6, wherein -the sensor of current parameters is placed in the main cabinet at the meter's input, and -said meter has a device to give an alarm signal and cut off the customer supply if the difference between the amount of electrical energy which has entered the meter and the amount of electrical energy fixed by the sensors of the personal cabinets over the same period of time exceeds the permissible value. 8. The meter according to Claim 5 or 6, wherein its cabinet (cabinets) is/are equipped with a device (devices) for giving a sound signal, disconnecting the customer from the power network and transmitting the alarm signal to electricity supplier if an unauthorized opening of a cabinet (tampering with cabinets) in which the meter is housed (or unauthorized cutting into a section of the power network controlled by the meter) has taken place. 9. Method of preventing excessive energy losses when the meter according to Claim 6 is employed and the following operations are performed in accordance with this method: -measuring the amount of electrical energy which entered the meter over a fixed period of time, -determining the total amount of energy fixed by the sensors in the personal cabinets over the same period of time, -determining real losses (the difference of the amount of electrical energy which entered the meter over some interval of time and the total amount of energy fixed by sensors in personal cabinets over the same interval of time), -comparing the determined real losses with the level of permissible losses, -disconnecting the consumers and giving an alarm signals if real losses exceed the permissible value.

Description

FIELD OF THE INVENTION

The present invention relates to devices for measuring and controlling the consumed electricity and is intended to perform these functions with guaranteed payments by consumers of electricity and prevent its unauthorized use (theft).

State of the art

A large number of various modern devices are known for measuring electric energy consumption using semiconductor logic and pulse technology elements, information converters (signals of one kind to another), including analog-digital (for example, US patent No. 3947763 from 1976, I8 C1 .. 342/142, Ιηΐ. C1. СО1В 11/32).

More modern meters of consumed electricity with programmable components are known, including a microcontroller, memory elements, a display, an interface. Such meters, among other things, react in a certain way to deviations of current or voltage in one direction or another of a given range (for example, US patent No. 5315 235 from 1994, I8 C1 .. 324/116, Ιηΐ. C1. C 01B 19 / sixteen).

Developed and programmable, with a developed logic of action, electricity meters, mainly for industrial facilities (see, for example, European Patent No. EP 0857978 A2 of 08/12/1998 (filed 02/21/1992), Ιηΐ. C1. 01B 22/00; its analogue US patent No. 5631843 from 05.20.1997 (claimed 6.06.1996).

Meters of a similar level are known including the use of sealed circuits of analog-to-digital converters (for example, US patent No. 5544089 of 1996 (filed June 7, 1995), I8 C1 .. 364/492, Ιηΐ. C1 С 06Е 17/00) .

The mentioned technical solutions are intended for use mainly in highly developed countries (with an appropriate level of culture of consumers of various kinds of services), in particular, for accurate measurement of consumed electricity in industrial and other sufficiently powerful enterprises (including with uneven loading of electric networks).

At the same time, in many countries of the world, especially in developing countries, including countries that were formed on the territory of the former USSR, there is a problem of payment for utilities, in particular, consumed electricity. To solve this problem, many well-known companies have developed and are producing electronic meters that transmit electricity to consumers only after it has been paid. A consumer who has such a meter installed pays for electricity and receives an electronic card (5 step 1 sagb), in the memory of which the amount paid by the consumer is entered. Next, the consumer inserts an electronic card into the meter, which remembers the amount paid and allows the consumer to receive the appropriate amount of electricity.

The indicated companies involved in such meters include, in particular: Eaib & Sug (Switzerland), Ωα1ο1οΚΐΓοη (Russia), ZsYitSgdsg (France), Ό.Μ.8. Μοΐοκ Sat (Great Britain), Co η 1 od 8οιι11ι of Lgpsa (South Africa), ΝίδΚο Rgo) ss1 E1ss1gop1S5 & Sottshsabosh Pb. (Israel). - see, for example, the specialized journal for measuring technology Ms1sppp ΙηΙθΓη; · ιΙίοη; · ι1. 1998, Ls 1, 8οιι11ι AGPS. Zsagogoidy Riysaboshch I-historyb (Ρΐу) Ш., р.р. 24-25.27.28-29.

Existing meters are for individual use. Each such counter contains a relay to turn off the consumer (after it has consumed the paid amount of electricity), a display (showing the amount remaining by that moment, which the consumer can still receive electricity), an interface, an electronic card information reading unit, an electric current parameter registration sensor, and a processor that stores information from an electronic card, calculates the amount of energy consumed by the consumer and the corresponding amount, calculates and transfers the display shows information about the remaining amount, remembers and transmits, upon request to the interface, information about the time variation of electric current parameters over the past six months, gives the relay a command to turn off the consumer when he has spent the entire amount paid - see, for example, the technical description for such counter (Rgs-RautsgI Mts1bVa1s Rgodgatta1s Rho \ gsg Ms1sg) developed by the company ΝίδΕο Rgo) ss1 E1ss1goshs5 & S'ottischabosch 6., 1995 (excerpts and drawing are given in the appendix to this application).

However, such meters have a high price (100-500 US dollars), and therefore the additional funds collected with their help do not allow you to recoup the costs for the purchase and installation of these meters in reasonable time.

Companies Ό.Μ.8. Μοΐοτκ Yb. (UK) and Wack-TssU Εΐ6. (Israel) developed consoles for existing induction meters, which also provide electricity supply after an advance payment. These consoles are cheaper than electronic meters, but still cost 70-90 US dollars together with induction meters, and their payback period is also unacceptable.

The indicated electronic meters and induction meters with prefixes are installed either in apartments or in the entrance. In both cases, the consumer has the opportunity to use electricity without payment (to steal electricity) by laying a wire past the meter.

However, it is easier and less risky for an attacker to steal electricity if the meter is installed in the apartment, and it is impractical to place the meters in the entrances, since in some cases the meters themselves are stolen and / or disabled.

For these reasons, electronic meters and set-top boxes for induction meters have not been widely used.

SUMMARY OF THE INVENTION

The aim of the present invention is to eliminate these disadvantages of the known technical solutions, i.e. creation of a meter of consumed electricity with its prepayment, acceptable to the consumer cost, while eliminating the possibility of theft of electricity by unscrupulous consumers.

The goal is achieved by the proposed meter, designed for reliable simultaneous servicing of many consumers, with the possible installation of one device on the porch, house or village (village, village, etc.).

The proposed counter, like a well-known counter of the same class, has a reader of information (for example, from an electronic card (kshay sagb)), a display for issuing information (in particular, to show the remaining payment amount), an interface for transmitting information to an external device about changes in the parameters of the electric current for a certain time, a processor for calculating the amount of consumed electricity, payments made, the amount of remaining funds, as well as for controlling the functional elements of the meter.

But, unlike the known ones, the proposed counter has a multiplexer connected to the outputs of the group of current parameter sensors (the number of at least the number of consumers served) and connected to a common processor to transmit the latest information about the parameters of the current consumption from each sensor as a function of time. The counter also has a common command device connected to the processor outputs for transmitting processor instructions to relay groups (in the amount of at least the number of consumers served) to disconnect the corresponding consumer from the mains if the specified consumption (level) is reached by the specified consumer.

With the described solution, a counter cost per customer is reduced, at least due to the fact that the interface, display, reader and processor are used alone for many consumers, and the widespread use of such meters becomes economically feasible. To increase the accuracy of measuring the parameters of the electric current, each sensor can be equipped with a current transformer, and an analog-to-digital converter (ADC) is switched on between the multiplexer and the processor with an switching frequency sufficient to provide a given class of accuracy in recording the current parameters in time. If it is impossible and / or inexpedient to use the ADC with a switching frequency sufficient to record the current parameters with a given accuracy, the sensor is equipped with a current transformer, a linear pulse generator and a pulse counter, the last of which is connected to the processor via a multiplexer.

- To simplify the design, the current parameter sensor can be equipped with a shunt (instead of a current transformer) connected to a linear pulse generator;

- moreover, the output of the latter through an optical circuit separator (optical pair) is connected to a pulse counter;

- output associated with the processor through the multiplexer, with the aim of improving operational safety.

To prevent attempts by unauthorized consumers to connect to the power grid and / or impact on meter elements, the latter are mounted in one box (protected from various types of influences), connected by individual wires to the premises of consumers under individual control. When consumers are located at a considerable distance from each other (in particular, in rural areas), when connecting consumers to the meter with an individual wire is not economically feasible, the meter

- made with placement in a central box and personal boxes for each consumer,

- and in the central box installed elements common to all consumers and the transceiver,

- And personal boxes are located in the immediate vicinity of each current consumer in a hard-to-reach place, and they have current sensors, relays and devices installed to ensure communication between personal and central boxes.

In the latter case, in order to prevent theft of electricity by connecting to the mains between the central and personal boxes, in addition to the sensors in personal boxes, a current parameter sensor is also placed at the entrance to the meter in the central box, and the meter is equipped with an alarm and shutdown device consumers in case of excess of the difference in the amounts of electricity included in the meter, and electricity recorded by the sensors of personal boxes for the same period of time.

At the same time, the boxes are equipped with devices for supplying an audible signal, disconnecting the consumer from the power supply network and transmitting an alarm signal to the electricity supplier in the event of unauthorized opening of the boxes (impact on the boxes) of the meter (or a section of the power grid under the control of the meter).

The proposed technical solution (when consumers are located at a considerable distance from each other) provides for the prevention of excess electricity losses based on the method in accordance with which:

- measure the amount of energy received in the meter for a fixed period of time,

- determine the total amount of electricity recorded by the sensors in personal boxes for the same period of time,

- determine the level of actual losses (the difference between the amount of electricity received in the meter and the total amount of electricity recorded by the sensors of personal boxes for the same period of time),

- compare the result of determining the actual losses with the level of permissible losses,

- disconnect consumers and give alarms in case of exceeding the actual losses of the acceptable level.

A comparative analysis of the proposed counter and known technical solutions for a similar purpose shows that the first has novelty, industrial applicability, inventive step, and therefore deserves legal protection in the form of a patent.

List of drawings

In FIG. 1 - shows a structural diagram of a basic version of the proposed counter;

in FIG. 2 is a structural diagram of a counter with an ADC and current transformers of current parameter sensors;

in FIG. 3 is a fragment of a structural diagram of a counter with a sensor current transformer, a linear pulse generator, and a pulse counter;

in FIG. 4 is a fragment of a structural diagram with a shunt of a current parameter sensor, a linear pulse generator, an optical splitter, and a pulse counter;

in FIG. 5 - layout of the main parts of the meter with the location of consumers at a considerable distance from each other.

Information confirming the possibility of carrying out the invention

The proposed counter in the basic version (Fig. 1) contains sensors 1 of the parameters of electric current (voltage and current), varying in time. The number of sensors is not less than the number η of connected consumers. The outputs of the sensors 1 ₁ -1 _{η are} connected to the inputs of the multiplexer 2, the output associated with the microprocessor 3 for sequential reading of the sensor readings (readings from binary counters in an amount equal to the number of consumers) and recording the results in non-volatile memory (necessary to store current readings in power outage).

The reader 4 is also connected to the microprocessor information from ksai-sagk about the amount of payment previously made by each consumer for the use of electricity.

A display 5 is also connected to the microprocessor 3 to provide information, in particular, on the remaining payment amount of each consumer (corresponding to the number of kilowatt hours of electricity that the consumer can still use up).

Further, an interface 6 is connected to the microprocessor for transmitting information to an external device on demand. Finally, a common command device 7 is connected to the microprocessor outputs, in particular, in the form of a decoder from a binary code to a positional one and an amplifier with an output current sufficient for the normal functioning of a relay (or semiconductor switch) 8 included in its circuit designed to turn on the power supply of each consumer, pre-paid electricity, and if the specific consumer consumes electricity at a predetermined value, the specified relay (key) 8 will ensure that the limit has expired the consumer from the mains (in total, the meter has η relays or keys 8 ₁ -8 _η corresponding to each consumer connected to the meter). To improve the accuracy of measuring the parameters of the electric current, each sensor can be equipped with a current transformer 9 and an amplifier 10 (Fig. 2), and between the multiplexer 2 and the microprocessor 3 an analog-to-digital converter (ADC) is switched on with a switching frequency that provides registration of the current parameters in time with predetermined accuracy.

If it is impossible and / or inappropriate to use the ADC with a switching frequency sufficient to register the current parameters with a given accuracy, the sensor is equipped with a current transformer 9 (Fig. 3), a linear pulse generator 12 and a pulse counter 13, the last of which is connected to the microprocessor via a multiplexer 3. Instead of a current transformer, a shunt 14 (Fig. 4) connected with a linear pulse generator 12 can be used; wherein the output of the latter through the optical splitter 15 circuits (optical pair) is connected to the pulse counter 13, the output connected to the microprocessor 3 through the multiplexer.

The specified generator 12, individual for each consumer, is designed to convert the numerical value of the incoming electricity into a sequence of pulses of a given duration, following with an interval proportional to the value of the active power (respectively, the incoming electricity).

To prevent attempts by unauthorized consumers to connect to the power grid and / or effects on meter elements, the latter are mounted in one box (protected from various types of influences), connected by individual wires to the premises of consumers under individual control.

When consumers are located at a considerable distance from each other (in particular, in rural areas), when connecting consumers to the meter with an individual wire is not economically feasible, the meter (Fig. 5)

- made with placement in the central box 16 and personal boxes 17 ₄ -17 _p for each consumer,

- and in the Central box installed elements common to all consumers (in particular, the functional elements 1, 3, 4, 5), and the transceiver 18,

- and personal boxes 171-17p are located in the immediate vicinity of each current consumer 19 ₁ -19 _p in an inaccessible place, and they have sensors 1 of current parameters, in particular, elements 14 ₄ -14 _p , 12 ₄ -12 _p , 13ι -13 _η , relay 8 ₄ -8 _p and devices 18 ₄ -18 _p for communication between personal and central boxes.

In the latter case, to prevent theft of electricity in addition to electricity between the central portion and a personal boxes, in addition to the sensors in personal boxes, at the entrance to the counter in a central box also available current parameters of the sensor, and is provided with a counter device 20, _p 201-20 to signal an alarm and turn off consumers when the difference between the amount of electricity included in the meter and the energy consumed by consumers (recorded by personal box sensors) for the same time iodine will exceed the allowed value. At the same time, the boxes are equipped with devices for supplying an audible signal to disconnect from the consumer’s mains and transmitting an alarm to the electricity supplier in case of unauthorized opening of the boxes (impact on the boxes) of the meter (or a section of the electric network under the control of the meter). The operation of the counter is as follows. For the normal functioning of the electricity generation system, consumers pre-pay electricity in a bank, which records in personal 8-step-1-step 8 the amount of energy paid by each consumer. To use electricity, consumers insert an 8 step (-sagY8 into the meter. Using a receiving device, the microprocessor records the amount of payment made by each consumer and the tariff coefficient corresponding to that consumer in the corresponding memory cell. After that, the microprocessor turns on the relay (or its non-contact equivalent is a semiconductor key ), i.e. the power supply of those consumers who paid for electricity. During operation of the meter, the microprocessor in conjunction with the multiplexer sequentially polls It reads all the sensors that transmit the electric current parameters in analog form, in particular the ADC. The latter converts them into digital form and transmits them to the microprocessor. The polling cycle is repeated with the switching frequency sufficient to ensure the specified accuracy class of the counter.

Such a frequency allows the microprocessor to calculate with the required accuracy the amount of electricity received by each consumer, and transfer to his cell information about the parameters of the electric current received by him, the amount of consumed electricity, the used and remaining amounts of payments, taking into account temporary tariffs. If the consumer used the full amount of the advance payment (and did not take care of the next payment), the microprocessor disconnects this consumer from the power supply system (mains) using a command device (and the corresponding relay). The consumer has the opportunity at any time to check the remaining part of the amount of payment for electricity. To do this, he must insert 8shag1-sagy into the counter, after which the microprocessor will display the remaining part of the payment amount remaining in the memory of this consumer. In another embodiment of the counter, a current parameter sensor comprising a current transformer (or shunt), a linear pulse generator and a pulse counter (the number of which is proportional to the amount of incoming electricity) transmits information about the parameters of the electric current and the amount of incoming energy directly to the microprocessor through the multiplexer.

In this case, the pulses generated by each generator 12, through optical isolation (performed by the counter with a shunt), to exclude galvanic communication between the mains and the microprocessor, fall into the 13 pulse counter (binary), interrogated by the microprocessor with a given time interval (with a given frequency). Each time after reading the readings, the counter 13 is “reset” to avoid overflow. The reading results are summarized in the consumer’s memory cell and compared with the value of the paid electricity. In this embodiment, information can be transmitted at a fairly low frequency. This allows you to transmit information from sensors through the multiplexer to the microprocessor using transceivers when placing the counter elements in different (in the central and personal for each consumer) boxes at a considerable distance from each other. But it is precisely with this arrangement of meter elements and consumers that an opportunity is more favorable for attackers to steal electricity by connecting to the electric network between the central and individual (personal) boxes. To prevent the theft of electricity using special devices installed in the boxes, sound signals are sent, a disconnect signal from the consumers' power supply network and an alarm signal to the electricity supplier in case of unauthorized opening of the meter box (or impact on the boxes) or impact on the power supply section controlled by the meter. The indicated function (theft prevention) is provided by transmitting to the microprocessor information about the amount of electricity received at the meter input and the total amount of electricity recorded by the sensors in personal units for a certain period of time, and then comparing these values. In case of theft of electricity, the difference between the indicated measured quantities of electricity will be greater than the allowable limit, leading to the above system actions.

Claims (9)

CLAIM 1. The meter of electric energy, ensuring the termination of its filing upon reaching the specified (paid) consumption, containing - sensors of parameters of electric current, changing in time, and a relay for disconnecting the consumer of electricity from the mains, - the reader of information from the smart card about the amount of payment previously made by each consumer for the use of electricity, - display for issuing information, - interface for the transfer of information on demand to an external device, - a processor that links these functional elements into the system for calculating the amount of electricity consumed, the amount of payments made by the consumer, determining the amounts of the remaining (unused) consumer funds, as well as for controlling the functional elements of the meter, characterized in that - additionally contains (p-1) sensors for the parameters of electric current and (p-1) relays for switching off electricity consumers, where p - the total number of said sensors and relays is at least equal to the number of consumers, - a multiplexer connected to the outputs of the current parameter sensors and the output connected to the processor for transmitting to the latter information about the parameters of the current consumed by each consumer as a function of time, - a controller connected to the processor outputs for transmitting the processor commands of the relay of the corresponding consumer to disconnect it from the power grid in the event that the power consumption specified by the consumer reaches the set value (level), - at the same time, the information reader is configured to record the amount of payment previously deposited by each consumer from the smart card of each consumer. 2. The counter according to claim 1, in which the sensor of current parameters is provided with a current transformer, and between the multiplexer and the processor an analog-to-digital converter with a switching frequency sufficient to ensure a specified class of accuracy of recording current parameters in time is included. 3. The counter of claim 1, wherein the current parameter sensor is provided with a current transformer, a linear pulse generator and a pulse counter, and the latter is connected to the processor via a multiplexer. 4. A counter in accordance with claim 1, wherein the current parameter sensor is provided with a shunt connected to a linear pulse generator, the latter output via an optical circuit breaker connected to a pulse counter connected to the processor via a multiplexer on output, to ensure operational safety. 5. The counter according to claim 1, the functional elements of which are mounted in one box connected by individual wires to the premises of consumers under individual control, to prevent attempts of unauthorized connections of consumers to the power grid and / or effects on the elements of the counter. 6. The counter according to claim 1, which, when the consumers are located at a considerable distance from each other, is arranged with placement in the central box and personal boxes for each consumer, with elements common to all consumers and the transceiver installed in the central box, and personal boxes are located in the immediate vicinity of each current consumer in an inaccessible place, they are equipped with current parameters sensors, relays and devices to ensure communication between personal and central boxes. 7. The counter according to claim 6, in which the current parameter sensor is located in the central box at the entrance to the meter, and the latter is also equipped with a device for generating an alarm signal and disconnecting consumers in case of exceeding the allowable value of the difference between the amount of electricity entered into the meter and electricity recorded by the sensors of personal boxes for the same period of time. 8. A meter according to claims 5, 6, in which its box (s) is provided (equipped) with a device (s) for generating a sound signal, disconnecting consumers from the power supply network and transmitting an alarm to the electricity supplier in the event of unauthorized opening of the box (impact on the boxes) meter (part of the grid, under the control of the meter). 9. The way to prevent excess electricity losses when using the meter according to claim 6, in which - measure the amount of energy received in the counter for a fixed period of time, - determine the total amount of electricity recorded by the sensors in personal boxes for the same period of time, - determine the level of actual losses (the difference between the amount of electricity received in the meter for a certain period of time, and the total amount of electricity recorded by the sensors of personal boxes for the same period of time), - compare the result of determining the actual losses with the level of permissible losses, - disconnect customers and give alarms in case of exceeding the actual loss of the permissible level.