TECHNICAL FIELD

The invention belongs to the electrotechnics field and can be used in manufacturing a multifunctional electric energy meter for accounting of energy consumption and for protection from unaccounted energy consumption and from disorders of operation of electricity supply circuit.

BACKGROUND ART

Widely known devices for electric energy accounting are induction and electronical energy meters, the mechanism, electric circuit and operating principle of which are described in technical resources, such as HJHOKOBHH A. M., «3jieκτpH ⁱ iecκHe CHeτHHKH», MocKBa, roceHeproκ3flaτ, 1963, p. 23-27, «O6cjiy>KHBaHHe HHΛVKΠ;HOHHBIX cπeTHHKOB H rjeπeii yπeTa B 3JieκτpoycτaHθBκax», MocKβa, 3HeproaτoMH3Λaτ, 1983, p. 5— 11. These electric energy meters consist of a turning element, which forms the circuits of electric voltage and current with the core, and the aluminium plate with a spindle of which turns when influenced by the magnetic flux and transfers the turning motion to the calculation mechanism by worm-gear. Such electric energy meters are connected to the grid of the supplier through an automatic switch, which protects the electric circuit from short- circuit currents and overloads, and in other cases it is switched on and off manually.

The disadvantages of these widely known electric energy meters are as follows: they only calculate the electric energy consumed, their readings are retrieved manually, current regulations forbid to connect an electric meter directly to the grid of the supplier, therefore there must be an automated switch in the consumer's electrical inlet before the meter. Besides, these electric energy meters have no effective protection from unaccounted usage of electric energy as the sealing of their casing cover provides no protection from influence of dishonest consumers on readings of the meter.

The technical solution that is the most similar to the invention is an electric energy accounting device which performs the functions of accounting the electric energy consumed and protects against unaccounted electric energy usage. It consists of a single- phase or three-phase electric energy meter with an additionally installed voltage coil, consumer connecting block and a module for protection from unaccounted electric energy usage, which consists of a current voltage transformer, with two wires passing through the magnetic core of which, through which electric current flows in two different directions: from the supplier's grid to the electric energy meter and the returns from the consumer's grid through the electric energy meter; the magnetic core is wrapped with a secondary winding in which the difference of the electric currents is induced and the terminals of which are connected to the bridge rectifier, the DC voltage contacts of which are connected in parallel to the electrolytic capacitor to which an electromechanical activator with an threshold control system is connected in parallel. The consumer's grid is connected to the outlet of the electric energy meter by the contacts of the consumer connecting block. One of the terminals of the phase conductor and the neutral conductor passed through the magnetic core are connected to the outlet of the automated switch, the other terminals are connected to the inlet of the electric energy meter. The phase conductor and the neutral conductor of the supplier's grid are connected to the automated switch inlet. Solid connection by connection block between the consumer's grid and the electric energy meter does not allow swapping of the phase conductor and the neutral conductor. When the usage of the unaccounted electric energy starts, the electromechanical activator with the threshold control circuit turns the automated switch off and this way the electricity supply to the consumer is terminated (LT patent No. 5473, IPC: GOlR 11/00, published 25/02/2008).

This known device is more advanced than the famous induction and electronical electric energy meters because alongside to accounting of the electric energy consumed, it also provides protection from the unaccounted electric energy usage. However these advantages do not compensate for the existing disadvantages because the device consists of three separate units, the consumer connecting block which is a part of such meter is of big size and has a complex system of contacts, the parameters of the current voltage transformer are determined by complex experiments therefore they are not sensitive enough in terms of reaction to the differences of the currents and protection from the unaccounted usage of electric energy is not effective, there is no possibility to control the voltage and current and power consumption, and a voltage coil must be additionally installed in the certified factory made electric energy meters. Besides, there is no possibility to automatically disconnect electricity supply to the consumer in case of malfunctioning of the electric circuit or in case of violation of permitted limits of the controlled parameters. There is also no possibility for remote transmission of data or receiving and carrying out the control instructions. The invention is aimed at increasing effectiveness of protection against the unaccounted electric energy usage and from malfunctioning of the electric circuit, expanding functions of the device to include the functions of measuring values of the supplied voltage and current, calculating the power consumption, collecting and remotely transferring the calculated and measured data, formulating the control commands and receiving as well as carrying out the remote instructions. Besides, one aims at mounting all the units in one device, namely the multifunctional electric energy meter, which could be used in place of the inlet accounting panel of the electricity consumer. SUMMARY OF THE INVENTION

The goal of the invention is achieved by mounting in the multifunctional electric energy meter an electric energy measuring device for accounting the energy consumed, an automated switch for direct connection to the supplier's grid, voltage indicator with light indication, which displays the supplied voltage before the automated switch, thermo- compensated current transformer with two primary windings, one of which is a phase winding and the other is a neutral winding, and one secondary winding to measure the supplied current, a processor with software, digital indicator to display the data on screen, remote two-way switching unit with an antenna to remotely transfer the data and to receive control commands, a module for protection of the unaccounted energy usage, which consists of current voltage transformer, the parameters of which are calculated according to the method developed by Habilitated Doctor (Physics), Professor Vilius Palenskis in order to measure the difference between the supplied and returning current more precisely and which has two primary windings one of which is a phase winding and the other is a neutral winding, and one secondary winding, the terminals of which are connected to the processor inlet and to the bridge rectifier, to the DC voltage contacts of which an electrolytic capacitor is connected in parallel, to the latter an electromechanical activator with threshold control circuit is connected in order to switch off the automated switch. The phase and neutral contacts of the supplier's grid, two connecting wires of the voltage indicator and processor inlet to measure voltage are connected to the automated switch inlet and one of the terminals of the phase and neutral primary windings of the current voltage transformer are connected to the phase and neutral contacts of the automated switch outlet, the other terminals of the windings are connected to the beginnings of the phase and neutral primary windings of the thermo-compensated current transformer, the second terminals of the windings are connected to the inlet contacts of the electric energy measuring device.

Furthermore, the inlets and outlets of the processor are also connected to the terminals of the secondary winding of the thermo-compensated current transformer to measure the supplied (consumed) current, with two-way switching module to transfer data and to receive control commands, with the electromechanical activator by threshold control circuit in order to transfer received and formulated control commands to turn off the automated switch. Moreover, in the processor, there are inlet and outlet units to measure the supplied voltage, supplied current, the difference between the supplied and the returning current, to calculate the power consumption and the electric energy consumed, to enter the permitted maximum values of the current and current difference, the minimum and maximum value of the voltage, to transfer the measured and calculated data to the digital indicator in order to display them on the screen and to transfer to the management centre of the electricity supplier by remote two-way switching module, to receive remote control commands, to compile data, to compare measured and calculated data with their preset values and to formulate control commands in cases of violation of preset permitted values of the controlled parameters, to transfer accepted remote and formulated control commands to the electromechanical activator with threshold control circuit in order to switch off the automated switch. The two-way switching module has a remote two-way connection with the management centre of the supplier and the processor.

DESCRIPTION OF EMBODIMENT

Fig. 1 presents the principal scheme of the multifunctional electric energy meter which reveals the essence of the invention.

Multifunctional electric energy meter consists of an automated switch 1, current voltage transformer with two primary windings and one secondary winding 2, thermo- compensated current transformer with two primary windings and one secondary winding 3, electric energy measuring device 4, voltage indicator with light indication 5, bridge rectifier 6, electrolytic capacitor 7, electromechanical activator 8 with threshold control circuit 9, processor 10 with software, inlets 11, 12, 13, 14 and outlets 15, 16 of the processor 10, digital indicator with a display screen 17, remote two-way switching module 18 with an antenna, outlet 19 of the electric energy measuring device 4, inlet 20 of the automated switch 1, consumer's grid 21, supplier's grid 22 and the casing 23 of the multifunctional electric energy meter. A multifunctional electric energy meter with such composition conforms to the requirements for the inlet accounting panel of the connection of the consumer's grid with the supplier's grid.

Below we present a description of the operation of the multifunctional electric energy meter.

The phase and neutral conductors of the consumer's grid 21 are connected to the outlet contacts 19 of the electric energy measuring device 4 and the phase (F) and the neutral (O) conductors of the supplier's grid 22 are connected to the contacts of the inlet 20 of the automated switch 1. After connecting the supplier's grid 22, the voltage indicator with light indication 5 lights on, the processor 10, the inlet 11 of which is connected with the phase and the neutral contacts of the inlet 20 of the automated switch 1 by connecting wires, starts measuring the value of the supplied voltage. After manually switching on the automated switch 1, to the phase and the neutral contacts of the outlet of which one of the terminals of the phase and the neutral primary windings or the current voltage transformer 2 are connected, the other terminals are connected with the beginnings of the phase and the neutral primary windings of the thermo-compensated current transformer 4, and the second terminals of the windings are connected to the inlet of the electric energy measuring device; and when there is a load in the consumer's grid, the current in the electricity supply circuit runs from the supplier's grid into the consumer's grid by the phase conductor (F) through automated switch 1, consecutively connected phase primary windings of the current voltage transformer 2 and thermo-compensated voltage transformer 3 and through the electric energy measuring device 4; and the current returning from the consumer's grid flows by the neutral conductor (N) through the electric energy metering device 4, and the consecutively connected neutral primary windings of the thermo-compensated current transformer 3 and the current voltage transformer 2 and through automated switch 1. When the current flows in the electricity supply circuit, the supplied current is constantly measured by thermo- compensated current transformer 3, in which the supplied and returning electric current flowing through the two primary windings induces electric current in the secondary winding and this current is proportional to the supplied (consumed) current and the difference of the supplied and returned currents is constantly measured by current voltage transformer 2, in which the supplied and returned currents going through the two primary windings induce the difference of the supplied and returned currents in the secondary winding only in case the supplier starts using unaccounted electric energy. When there is no malfunctioning in the electricity supply circuit that occur when the preset permitted values of the control parameters entered in the processor are violated (namely, permitted maximum and minimum values of the supplied voltage, maximum permitted supply current, maximum permitted consumption power, maximum permitted difference of the supplied and returned currents, which occurs when unaccounted energy is consumed), the processor 10 by inlet 11, which is connected to the phase and neutral contacts of the inlet 20 of the automated switch 1, measures the value of the supplied voltage by inlet 12, which is connected to the ends of the secondary winding of the current voltage transformer 2, measures zero difference between the supplied and returned currents, by inlet 13, which is connected to terminals of the secondary winding of the thermo-compensated current transformer 3, measures the value of the supplied current and constantly calculates the power consumption (P) in kilowatts and consumed electric energy in kilowatt-hours (kWh) according to the values of the supplied voltage (U) measured in volts (V) and supplied current (I) measured in amperes (A) and the cosine of the angle phi; transfers the measured and calculated data to the digital indicator 17 in order to display them on the screen and to the remote two-way switching module 14 in order to transfer them to the supplier's measurement centre and does not formulate any control commands. If at least one of the controlled parameters violates the preset value, the processor 10, by comparing the parameters, records a violation of the permitted value of the certain parameter and formulates a control command, which by outlet 15, which is connected to the DC voltage contacts of the bridge rectifier, informs the electromechanical activator 8 with the threshold control circuit 9 to switch off the automated switch 1, which disconnects the supplier's grid 22. Besides, when the use of unaccounted electric energy is started, the supplier's grid 22 is also disconnected by the automated switch 1 because of activation of the circuit of the protection from the unaccounted electric energy usage module as the terminals of the secondary winding of the current voltage transformer 2 are also connected with the AC voltage contacts of the bridge rectifier 6, and the contacts of the DC voltage are connected with the electrolytic capacitor 7 in parallel to which the electromechanical activator 8 with the threshold control circuit 9 is connected in parallel. The AC current induced in the secondary winding of the current voltage transformer is proportional to the difference between supplied and returned currents; the bridge rectifier 6 transforms the induced AC current into DC current. The measured and calculated data for the remote two-way switching module 18 are transferred by the outlet 16 of the processor 10 to the electricity supplier's management centre, where the remote control commands are determined or the permitted values of the controlled parameters are corrected, the signal to switch off the automated switch 1 is transferred to the remote two-way switching module 18 which transfers them to the processor 10 through inlet 14. The digital indicator 17 displays the following data on the screen: the power consumption in watts (W), the supplied electric current in amperes (A), the supplied electric voltage in volts (V), the discharge electric current occurred (the difference between the supplied and returned currents) in amperes (A), the electric energy consumption in kilowatt-hours (kWh). Furthermore, after switching on the automated switch 6, the screen of the digital indicator 17 displays the reasons of the previous disconnection and the data about the disconnection reasons can be stored in the memory of the processor 10 for one year.

The multifunctional electric energy meter of the proposed configuration, compared to the closest technical solution, protects from unaccounted electric energy consumption and from malfunctioning of the electricity supply circuit much more effectively, performs more functions: accounts the consumed electric energy, measures the voltage and current supplied, the difference between the supplied and returned currents, which occurs when an unaccounted consumption of the electric energy starts, calculates the power of consumption and the consumed electric energy, displays the measured and calculated data on the screen, compiles and stores data for a set period of time, compares data with their preset values, remotely transfers and receives the remote control commands, formulates control commands when electricity supply circuit is malfunctioning or when at least one of the controlled parameters violates its permitted value, transfers the received and the formulated control commands to the electromechanical activator in order to switch off the automated switch after the switching off of which the electricity supply to the consumer is terminated. Besides, all the units are mounted in one casing, a multifunctional electric energy meter, which can be consumed instead of the inlet accounting panel of the electricity consumer and which effectively protects the electricity supply circuit and the consumer devices connected to it from the following malfunctions: current overload, short-circuit, unacceptably high discharge current which can generate a fire, unacceptably high or low voltage of the grid, which can damage the electrical equipment connected to the consumer's grid and to start a fire. It also allows for the electricity supplier to compare the readings of the electric energy meter 4 with the calculated data of the processor 4, to remotely control and manage electricity supply, to protect their interests from higher power consumption than permitted and from influence of dishonest consumers on the readings of the meter in order to reduce them.