CN115754462A - Electricity stealing prevention system and method - Google Patents

Abstract

The invention relates to a current sampling electricity larceny prevention system and a method, wherein the system comprises: the sampling circuit is used for monitoring each phase of electrical parameters of the ammeter; the signal processing circuit is used for performing superposition operation and/or analog-to-digital conversion on at least part of the electrical parameters acquired by the sampling circuit and outputting a digital signal and a non-full wave identification signal; the non-full-wave identification circuit is used for performing integral amplification operation on the non-full-wave identification signal output by the signal processing circuit and outputting a driving signal; the controller responds to the digital signals of the signal processing circuit, performs single-phase and phase-combination electric energy metering operation on the circuit and judges the electricity utilization state of the circuit where the electricity meter is located based on time sequence change analysis of the digital signals; the controller can also judge whether the circuit where the ammeter is located has non-full-wave power consumption by combining with the non-full-wave identification circuit, so that the system can accurately and effectively identify the non-full-wave power consumption and other forms of power stealing behaviors on the basis of obtaining high-quality electric energy metering data.

Description

Electricity stealing prevention system and method

Technical Field

The invention relates to the technical field of electric energy metering and electricity consumption monitoring, in particular to electric parameter monitoring and electricity stealing prevention of an ammeter, and specifically relates to an electricity stealing prevention system and method.

Background

With the progress and development of the times, electric energy becomes an indispensable part of life, and the fairness and the accuracy of electric energy metering relate to the legal rights and interests of the nation, electric power enterprises and vast electric power customers; however, some users often forbid the electricity stealing behavior for capturing the improper benefit, and the electricity stealing means are numerous. The electricity stealing modes aiming at the electric energy metering device mainly comprise the following two types: firstly, an external electric field and a magnetic field are applied to interfere the electric energy metering device, so that the electric energy meter cannot work normally; and secondly, the electric load nonlinear transformation output of the current transformer of the metering device in an extreme state is applied to cause the loss of electric quantity.

Because a large number of harmonic elements are arranged on the load side, such as the one-way conduction characteristic of a high-power diode, and the conduction control of a thyristor, the load current becomes non-full-wave current containing fundamental waves and multiple harmonics, and the metering principle of an electronic electric energy meter internally adopting electromagnetic induction type current sampling is extremely sensitive to the harmonic component of input current voltage, the main reason is the magnetic saturation principle of an iron core in a current transformer, when a non-full-wave rectifying device is additionally arranged on the load side, the current waveform output by the secondary side of the transformer does not keep a linear transformation relation any more, distortion and serious distortion can occur, and at the moment, the current signal can be approximately regarded as a direct current signal with a larger ripple coefficient. The current transformers are mostly arranged in electric energy meters adopted in China at present, and when electric energy waveform acquisition with extremely large harmonic components is carried out, the metering devices generate huge errors according to waveform distortion conditions, and even lose the metering function; a large number of repeated experiments show that due to the limitation of the frequency spectrum range of the iron core, the originally metered non-full wave of the mutual inductor is only metered to about 30% of normal electric energy due to the influence of waveform distortion in practice. Therefore, some illegal users utilize the magnetic saturation characteristic of the iron core current transformer when the iron core current transformer is not in full-wave load, a non-full-wave rectification circuit is added on one side of the rear load of the electric energy meter to convert sine wave current in a power supply circuit into non-full-wave current, and the iron core of the current transformer is saturated by direct current components in the non-full-wave current, so that load waveform distortion is caused, the electric energy metering device cannot meter normally, and the purpose of reducing the pay fee is achieved.

In the prior art, for example, a patent with publication number CN110308314A discloses a low-voltage anti-theft switch, which includes a voltage sampling module, a current sampling module, a power module, a controller module, a clock module and a communication module; the low-voltage anti-theft switch is connected in series with the power line and is positioned at the front end of the electric energy meter; the power supply module supplies power; the voltage sampling module samples a power line voltage signal and uploads the power line voltage signal to the controller module; the current sampling module samples a current signal of the power line and uploads the current signal to the controller module; the clock module provides a clock signal; the controller module receives the voltage and current sampling signals to measure the electric energy and communicates with the outside through the communication module. The low-voltage electricity stealing prevention circuit is additionally provided with the low-voltage electricity stealing prevention switch with the metering and communication functions in front of the electric energy meter, and the prevention, discovery and uploading of electricity stealing behaviors are realized in a mode of comparing the metering data of the low-voltage electricity stealing prevention switch with the metering data of the electric energy meter; however, the additional switch and the ammeter in the patent have repeated functions, which causes cost increase, and the detection mode is not suitable for a non-full-wave load type electricity stealing circuit.

The patent with publication number CN2716844 discloses a multifunctional electricity larceny prevention power monitoring device, which comprises a power circuit and a single chip microcomputer, wherein the periphery of the single chip microcomputer comprises a memory, a clock circuit, a switch circuit for protecting equipment and the like, and the multifunctional electricity larceny prevention power monitoring device is structurally characterized in that a current transformer and a voltage transformer are adopted to respectively collect the current quantity and the voltage quantity of each phase line, and the current transformer is adopted to collect the current quantity of a zero line G; the acquired current quantity and voltage quantity are respectively sent to an analog-to-digital converter in the single chip microcomputer, the single chip microcomputer processes the current quantity and the voltage quantity according to a mathematical operation model, the voltage, the current direction and the current unbalance degree of the load are obtained through calculation, and the nature, the state and the circuit of the load are judged to determine whether the electricity stealing and leakage conditions exist; the technical scheme of the patent acquires and converts circuit parameters of each phase to obtain information for judging whether the circuit is normal or not.

Patent with publication number CN113567720A discloses a serial direct current half-wave electricity stealing behavior detection method and system based on big dipper, including: acquiring the load current of the user side in the abnormal line based on the Beidou short message communication mode; carrying out harmonic content analysis on the load current to obtain a direct current component value; and judging whether the direct current injection quantity is abnormal or not according to the direct current component value so as to obtain a judgment result of the series direct current half-wave electricity stealing behavior.

Based on the above analysis, most of the conventional electricity larceny prevention monitoring circuits based on electric parameter analysis of the electric meter are based on direct sampling measurement of single-phase or three-phase electric parameters of the electric meter to obtain initial signals for judgment and analysis, and the structures and connection relations of the sampling measurement circuits are improved less to improve the initial signal acquisition precision and improve the overcurrent capacity and the load capacity of the electric meter, i.e., most of the conventional electricity larceny prevention devices or systems are arranged in a single channel aiming at the monitoring circuits of each phase of electric parameters, so that the monitoring circuits are prone to generate an overheating phenomenon and are not beneficial to accurate sampling of current and voltage data in a high-load state.

And the signal processing circuit and the analysis circuit in the prior art are not suitable for the situation that a multi-channel monitoring circuit is adopted for each phase, namely, the signal sampling circuit and the signal processing and analysis circuit are redesigned to obtain high-quality electrical data, and non-full-wave power utilization and other forms of power stealing behaviors are accurately and effectively identified according to the high-quality electrical data.

Furthermore, on the one hand, due to the differences in understanding to the person skilled in the art; on the other hand, as the inventor studies a lot of documents and patents while making the present invention, but the space is not detailed to list all the details and contents, however, this invention doesn't have these prior art features, but this invention has all the features of the prior art, and the applicant reserves the right to add related prior art in the background art.

Disclosure of Invention

Aiming at least part of the defects proposed by the prior art, the application provides an electricity larceny prevention system which can be used for electricity larceny prevention detection and identification of a single-phase, three-phase three-wire or three-phase four-wire electric meter, and the system comprises: the sampling circuit is used for monitoring each phase of electrical parameters of the electric meter and is provided with a multi-channel bridge circuit with a plurality of alloy bridges, so that the sampling circuit can obtain the electrical parameters of the multi-channel bridge circuit, wherein the electrical parameters at least comprise bridge circuit current/bridge circuit voltage and/or access voltage output by the alloy bridges after linear conversion; the signal processing circuit is used for performing superposition operation and/or analog-to-digital conversion on at least part of the electrical parameters acquired by the sampling circuit and outputting a digital signal and a non-full wave identification signal; the non-full-wave identification circuit is used for performing integral amplification operation on the non-full-wave identification signal output by the signal processing circuit and outputting a driving signal; the controller responds to the digital signal of the signal processing circuit and performs single-phase and/or three-phase electric energy metering operation on the circuit; under the condition that the non-full-wave identification circuit outputs a driving signal based on the non-full-wave identification signal and transmits the driving signal to the controller, the controller performs non-full-wave identification on the digital signal in response to the driving signal of the non-full-wave identification circuit, and when the digital signal sampling value has unipolar distribution, the circuit where the electricity meter is located is judged to be in non-full-wave electricity utilization.

The application applies the linear sensing sampling characteristic of a multi-channel bridge type alloy material to realize the electricity larceny prevention system and the electricity larceny prevention method aiming at the condition that the nonlinear conversion relation of primary current and secondary current of the current electromagnetic induction type metering current sensor under a non-full wave load results in less metering electricity consumption. The system comprises: the sampling circuit is used for monitoring each phase of electrical parameters of the electric meter, the voltage signal adopts a conventional sampling method, and the current realizes the linear transformation relation of the primary current and the secondary current by applying multichannel bridge type alloy material distributed sampling; the signal processing circuit is used for performing superposition operation and/or analog-to-digital conversion on secondary signal parameters of each alloy material bridge linear transformation acquired by each phase current distributed sampling circuit and outputting a digital signal and a non-full wave identification signal; the non-full-wave identification circuit is used for performing integral amplification operation on the non-full-wave identification signal output by the signal processing circuit and outputting a driving signal; the controller responds to the digital signal of the signal processing circuit, performs single-phase and phase-combination electric energy metering operation on the circuit and judges the power utilization state of the circuit where the electric meter is located based on time sequence change analysis of the digital signal; the controller can also judge whether the circuit where the ammeter is located has non-full electricity by combining with the non-full wave identification circuit, so that the system can accurately and effectively identify the electricity stealing behavior of the non-full electricity and the phenomenon that the load waveform distortion causes less electricity metering of the electric energy metering device due to the fact that the distributed energy is connected into a public power grid system on the basis of obtaining high-quality electric energy metering data.

Aiming at the problem that a sampling circuit of an ammeter is subjected to structural transformation to improve overcurrent capacity and load capacity in the prior art, the anti-theft system configures the sampling circuit of each phase into a multi-channel bridge circuit structure, namely, the sampling detection position does not only directly act on an access conductor connected with an ammeter terminal, the access conductor can be separately arranged to form two ends for input and output, corresponding alloy bridge circuits are arranged between the two ends as required, the number and specification of the alloy bridges can be determined according to the capacity of the ammeter, the multi-channel alloy bridge not only can improve the overcurrent capacity of the ammeter based on parallel arrangement, but also can reduce the heat productivity of the alloy bridge based on shunt effect, especially under the condition that the ammeter operates in a high load state for a long time, for example, when the current is constant, the single-channel power loss is P1= I ² * And R, when R of the multiple channels is constant, the power of the multiple channels is as follows: p2= n (I/n) ² ×R＝I ² N R, then P2 can be much smaller than P1 depending on the number of channels. Meanwhile, when a certain channel sampled by the same phase current fails, the current of the failed channel automatically flows through other channels in the same phase, and the probability of the complete machine failure can be reduced based on multi-channel setting on the basis of not influencing the sampling result. For example, the maximum load capacity of a manganin resistance single-bridge sampling element adopted at present is 80A, but various faults are easily caused due to overhigh circuit temperature rise caused by the power loss of the manganin resistance single-bridge sampling element. Meanwhile, as the number of electric equipment of users is increased, the utilization rate of the equipment is unpredictable, and a load overload situation appears in many times, the method is a main reason for causing the faults of the metering device at present. Therefore, when the multi-loop alloy bridge is adopted, the sampling precision during heavy load is improved, and the overcurrent and overload capacity of the sampling loop is improved. In addition, when one bridge circuit is in fault, the load current can pass through other bridges, so that the fault-tolerant capability of the sampling circuit is ensured.

The arrangement of the multi-channel alloy bridge also provides more alternatives for the electrical parameter sampling arrangement, detection positions or monitoring points can be set in a targeted manner according to different analysis side points to obtain electrical parameters such as current and voltage of multiple channels, the applicability of the sampling circuit can be obviously improved, more levels of electrical parameters can be obtained for analysis and processing, and the method has important significance for the effectiveness and the accuracy of electricity larceny prevention identification based on electrical parameter analysis; the multi-level high-quality electrical data can also be used as a data source for single-phase and three-phase electric energy metering operation of the electric meter, and the accuracy of the electric energy metering operation of the electric meter can be obviously improved. The system is matched with a setting mode that a sampling circuit carries out multichannel electrical data acquisition on each phase based on a multichannel bridge circuit, a signal processing circuit is arranged on each phase, the signal processing circuit comprises a superposition circuit and an analog-to-digital conversion circuit, the superposition circuit is used for carrying out superposition operation on unidirectional multichannel data to obtain single-phase data, the single-phase data can integrate and superpose data characteristics of each channel, including amplitude, frequency, waveform and the like, the data quantity of subsequent processing can be reduced while the data detail is enriched, the requirement of the system on circuit hardware is reduced, and the system conforms to the requirements of energy consumption and cost control; part of the analog signals processed by the superposition circuit are converted into digital signals under the action of an analog-to-digital conversion circuit, and the digital signals are transmitted to a controller for electric energy metering, analysis and operation, storage and communication and the like; the part of analog signals after being acted by the signal processing circuit are used as input signals of the non-full-wave identification circuit, the non-full-wave identification circuit carries out non-full-wave electricity utilization detection based on integral amplification operation, under the condition that circuit abnormality is detected, a driving signal is output to the controller, non-full-wave identification analysis is carried out on the digital signals, and when the digital signals are detected to be in a unipolar distributed mode in a plurality of time periods, the circuit where the electricity meter is located is judged to be in a non-full-wave electricity utilization state.

The controller can also judge whether the circuit where the ammeter is located has non-full-wave power consumption by combining with the non-full-wave identification circuit, and the power consumption state of the circuit where the ammeter is located is judged based on the time sequence change analysis of the digital signals; the time sequence change analysis of the digital signals can carry out multi-dimensional analysis on the electric energy data and the electric parameters of the circuit where the electric meter is located based on modes of electric energy accumulated data comparison or load curve prediction analysis and the like, so that the system can accurately and effectively identify electricity stealing behaviors in other forms on the basis of obtaining high-quality electric energy metering data.

Preferably, in order to ensure accurate identification of unipolar distribution in the digital signal and eliminate the condition that the digital signal sampling value has unipolar distribution due to power grid fluctuation caused by new energy and other factors, the unipolar distribution is the condition that one or more sampling points of the sampling amplitude before and after the digital signal sampling value has zero-crossing suddenly change to zero within the same cycle and continuously appear within a set number of cycles or more. For example, when the sampling values of the digital signals have unipolar distribution or one or more sampling points of the sampling amplitude before and after zero crossing suddenly change to 0 in the same cycle, the circuit where the ammeter is located is judged to be not full-wave power utilization in the cycle. In order to eliminate power grid fluctuation interference caused by new energy and other factors, when the circuit where the electric meter is located is judged to be non-full-wave power utilization, the circuit is determined to be non-full-wave power utilization after the similar conditions of the set number and above cycles occur, otherwise, the circuit is judged to be power grid disturbance, and the set number can be set according to the fluctuation frequency reported by the power grid, for example, whether the power grid continuously appears in a range of 10 cycles or not is judged. Specifically, the non-full wave refers to a case where the power load is not a zero-crossing 0 when the power supply is a normal line-frequency sine wave, or a case where the waveform suddenly drops to 0 before and after the waveform crosses 0. In the judgment logic, the time length of each cycle of the power frequency sine wave is 20 milliseconds, the continuous measurement time length is 200 milliseconds and 10 cycles are total, and similar situations continuously occur, the operation is determined to be non-full wave operation, otherwise, the power grid disturbance is judged. The multichannel alloy bridge circuit is arranged on the basis of single-bridge current control to reduce circuit heating loss and thermal offset, so that the alloy bridge keeps more stable physical characteristics, multichannel parameters are favorably superposed to form fine electrical data, actual electrical parameters and waveform changes of a circuit where an electricity meter is located are accurately reflected, waveform data judgment in a non-full-wave identification process can be assisted, especially under the condition that non-full-wave electricity utilization needs to be continuously judged in terms of amplitude and time domain, the accuracy of non-full-wave electricity utilization identification can be remarkably improved on the basis of judgment specifications of a sampling circuit and a non-full-wave identification circuit of the multichannel alloy bridge in the non-full-wave electricity utilization identification process, and on the basis of effectively filtering power grid fluctuation signals, the identification accuracy can be improved by 30% -50% compared with the prior art.

Preferably, the sampling circuit is provided with an access conductor connected with the electric meter terminal, the access conductor comprises an input end and an output end which are separately arranged, the input end and the output end are respectively connected with the electric meter terminal in a detachable mode, and a plurality of alloy bridges are arranged between the input end and the output end in parallel, wherein the alloy bridges are configured to be identical or proportional in the electric parameters and can be adjusted to structures with different electric parameters under specific conditions. Under the condition that two ends of a plurality of alloy bridges are respectively connected with the input end and the output end of the access conductor in a welding or integrated forming mode, each alloy bridge is provided with a first detection position for monitoring bridge circuit current or bridge circuit voltage of the alloy bridge, wherein a plurality of detection points of the first detection position are arranged in an axisymmetric or centrosymmetric mode relative to the alloy bridge. In the case of an input or output of the access conductor equipped with a second detection bit for monitoring the access voltage, several alloy bridges are arranged in parallel between the input and the output in the same physical specification or in a scaled configuration of the physical specification. The arrangement quantity and physical parameters of the alloy bridges can be comprehensively determined according to the capacity of the electric meter, and when the resistance determined by the physical parameters and materials of the alloy bridges is smaller, the current which can flow through the alloy bridges is larger, namely the combination and matching of the multiple alloy bridges can be suitable for the electric meters with different capacities, and the modularized manufacturing is facilitated.

Preferably, the non-full wave identification circuit is further at least communicatively coupled to a processing unit for receiving a non-full wave identification signal of the non-full wave identification circuit to obtain a continuously detected identification result, wherein the processing unit is only configured to obtain a sampling accuracy of the sampled data. The processing unit forms a sampling precision fluctuation curve based on the sampling precision of the sampling data, confirms the alloy bridge over-current condition of the current data source based on the slope of the current data point position in the curve, and sends an instruction for adjusting the over-current parameters to the alloy bridge based on the over-current condition. Based on the adjustment, the over-current capacity guarantee of the sampler bridge is realized, the accuracy of the sampled data is considered, the sampled data is directly analyzed to form an adjustment decision of the over-current capacity of the sampling bridge, the adjustment decision can be directly formed at a line level of a sampling circuit more quickly, and the problems of low measurement precision caused by external loop detection, especially inaccurate data caused by sampling bridge loss or sampling data precision loss due to the fact that adjustment cannot be fed back in time are avoided.

Preferably, in a case where the input terminal and the output terminal of the incoming conductor are configured in a symmetrical structure with each other, the alloy bridge may be configured in a circular or polygonal sectional shape, wherein when the alloy bridge is configured in a polygonal sectional shape, the input terminal, the output terminal, and the alloy bridge may be configured in a rectangular sheet shape having a thickness smaller than a length and a width. The alloy bridge and the access conductor of the rectangular sheet structure can be conveniently processed, the isolation structures among all the phase sampling circuits are conveniently arranged, the volume requirement of the device is reduced on the basis of ensuring the collection of electrical parameters, and the device is suitable for miniaturization, integration and modularized installation of an electric meter.

Preferably, the signal processing circuit is configured with a superimposing circuit that performs a superimposing operation on the bridge voltage or the bridge current based on the adder and outputs the non-full-wave identifying signal and the analog signal to the non-full-wave identifying circuit and the analog-to-digital converting circuit, respectively, and an analog-to-digital converting circuit. The analog-to-digital conversion circuit converts an analog signal input by the superposition circuit into a digital signal and transmits the digital signal to the controller, wherein the controller is provided with a clock module, and the clock module provides a main clock signal for realizing synchronous sampling to the sampling circuit, the signal processing circuit and the non-full wave identification circuit through the controller. In order to realize three-phase synchronous sampling, the main clock signals adopted by the sampling circuit, the signal processing circuit and the non-full-wave identification circuit for each phase are uniformly provided by the controller, so that the sampling calculation precision can be further improved.

Preferably, where the controller is provided with a digital isolator, the signal processing circuitry and non-full wave identification circuitry of each phase are connected to different ports of the digital isolator in a manner to enable independent power supplies and independent signal paths to be obtained. The system supplies power to the signal processing circuit and the non-full wave identification circuit of each phase independently, realizes the transmission of energy and signals in a multi-path magnetic, field and optical isolation mode, and can finish the sampling, processing and conversion of single-phase current and voltage signals and the identification of non-full wave signals aiming at the sampling circuit, the signal processing circuit and the non-full wave identification circuit of each phase.

The application also proposes a method of preventing fraudulent use of electricity, implemented on the basis of the aforementioned system of preventing fraudulent use of electricity, comprising one or more of the following steps:

setting a sampling circuit, a signal processing circuit and a non-full wave identification circuit for each phase of the ammeter;

the sampling circuit is provided with a multi-channel bridge circuit with a plurality of alloy bridges, the sampling circuit can acquire electrical parameters of each phase, and the electrical parameters at least comprise bridge current/bridge voltage and access voltage of each alloy bridge;

at least part of the electrical parameters acquired by the sampling circuit are subjected to superposition operation and/or analog-to-digital conversion, a digital signal and a non-full-wave identification signal are output, and a controller is used for performing single-phase and phase-combining electric energy metering operation in response to the digital signal;

under the condition that the non-full-wave identification circuit outputs a driving signal based on the non-full-wave identification signal and transmits the driving signal to the controller, the controller performs non-full-wave identification on the digital signal in response to the driving signal of the non-full-wave identification circuit, and when a sampling value of the digital signal is in unipolar distribution, the circuit where the ammeter is located is judged to be in non-full-wave power utilization;

the unipolar distribution is the condition that one or more sampling points of the sampling amplitude of the digital signal sampling value are suddenly changed into zero before and after the zero crossing of the same cycle and continuously appear in the range of the set number and above cycles;

the signal processing circuit comprises a superposition circuit and an analog-to-digital conversion circuit, and the signal processing circuit and the non-full wave identification circuit are connected with the controller in a mode of acquiring a main clock signal and an independent power supply;

the sampling circuit transmits the acquired electrical parameters to the signal processing circuit, and the superposition circuit superposes a plurality of alloy bridge circuit currents/bridge circuit voltages acquired by the sampling circuit based on the adder to acquire single-phase currents/one-way voltages and non-full-wave identification signals;

the bridge circuit current/bridge circuit voltage obtained by the sampling circuit is processed by the superposition circuit and then respectively output to the non-full-wave identification circuit and the analog-to-digital conversion circuit, the access voltage obtained by the sampling circuit is processed by the superposition circuit and then output to the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit can convert the single-phase current/unidirectional voltage and the access voltage into digital signals and transmit the digital signals to the controller.

Drawings

FIG. 1 is a schematic diagram of the system of a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a sampling circuit according to a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a signal processing circuit according to a preferred embodiment of the present invention;

fig. 4 is a schematic diagram of a non-full wave identification circuit according to a preferred embodiment of the present invention.

List of reference numerals

1: an electricity meter terminal; 2: a phase A terminal; 3: a B-phase terminal; 4: a C-phase terminal; 5: an N-phase terminal; 6: a sampling circuit; 7: connecting a conductor; 8: an input end; 9: an output end; 10: hole site; 11: an alloy bridge; 12: a first sampling bridge; 13: a second sampling bridge; 14: a first detection bit; 15: a second detection bit; 16: a signal processing circuit; 17: a controller; 18: a non-full wave identification circuit; 19: and a communication module.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

The application provides an electricity larceny prevention system, as shown in fig. 1, the system comprises a sampling circuit 6 connected with a single-phase or three-phase electric meter, the sampling circuit 6 can monitor and sample each phase of the electric meter to obtain electric data for electric energy metering, the electric data can be voltage signals or current signals, the current signals or the voltage signals obtained by the sampling circuit 6 are transmitted to a signal processing circuit 16, the signal processing circuit 16 can convert analog signals such as electric signals into digital signals and perform corresponding digital operation, so that a controller 17 can apply the processed signals to electric energy metering, circuit state analysis, non-full-wave identification and the like, the multi-dimensional analysis of the system on electricity larceny behaviors is improved to improve the accuracy and effectiveness of electricity larceny investigation, and the electric data can be compared with historical data or predicted data to evaluate the electricity utilization state. Specifically, the connection position of the sampling circuit 6 and the electric meter may be the electric meter terminal 1 of the electric meter, taking a three-phase electric meter as an example, the electric meter terminal 1 includes an a-phase terminal 2, a B-phase terminal 3, a C-phase terminal 4 and an N-phase terminal 5, each phase electric meter terminal 1 includes an input terminal and an output terminal, so that the sampling circuit 6 can perform electric data monitoring on each phase of the electric meter to acquire more detailed electric data, and the single-phase electric meter only includes the a-phase terminal 2 and the N-phase terminal 5.

Aiming at the problems that most of the existing sampling circuits 6 for monitoring the electric data of the electric meter obtain initial signals for judgment and analysis based on the direct sampling measurement of single-phase or three-phase electric parameters of the electric meter, and the sampling circuit structure and the connection relation are improved less to improve the initial signal acquisition precision and improve the overcurrent capacity and the load capacity of the electric meter, the sampling circuits 6 are set to be of a multi-channel bridge structure aiming at each phase of the electric meter, compared with a single-channel structure, multi-group components of the electric data can be obtained by acquiring information through a plurality of groups of sampling channels, and the accuracy of the electric data analysis result can be improved by the combined analysis of the multi-group components; the multi-combination alloy bridge 11 type circuit arranged in parallel in the sampling circuit 6 can also obviously improve the overcurrent capacity and the load capacity of the ammeter; specifically, as shown in fig. 2, for the a/B/C phases of the electric meter, the sampling circuit 6 is provided with an access conductor 7 for inputting and outputting electric energy for each phase, the access conductor 7 includes an input end 8 and an output end 9, which are separately arranged, and the input end 8 and the output end 9 are both provided with hole sites 10 for connecting terminals of a terminal knob box of the electric meter, so that the sampling circuit 6 can be detachably connected with the electric meter terminal 1, and the hole sites 10 can be arranged at positions opposite to the input end 8 and the output end 9 to enhance the stability of the connection; the split input end 8 and the split output end 9 are connected through a plurality of alloy bridges 11 which are arranged in parallel, two ends of each alloy bridge 11 are respectively connected with the input end 8 and the output end 9 of the access conductor 7 in a welding or integrated forming mode, each alloy bridge 11 is provided with a first detection position 14 for monitoring the voltage of two ends of each alloy bridge 11, and the input end 8 or the output end 9 of the access conductor 7 is provided with a second detection position 15 for monitoring the voltage of the access conductor 7; for the N-phase of the electricity meter, the sampling circuit 6 also has an input 8 for the supply conductor 7 and a second detection location 15 for monitoring the voltage of the supply conductor 7, the second detection location 15 being arranged at the input 8.

In order to improve the structural arrangement effect of the sampling circuit 6, so that the sampling circuit 6 can adapt to the internal space of the electric meter and acquire multi-channel electrical parameter information in terms of manufacturing, matching installation and arrangement structure, as shown in fig. 2, an alloy bridge 11 of the sampling circuit 6 is at least provided with a first sampling bridge 12 and a second sampling bridge 13, the first sampling bridge 12 and the second sampling bridge 13 are arranged in parallel, and two ends of the first sampling bridge 12 and the second sampling bridge 13 are respectively connected with an input end 8 and an output end 9 of the access conductor 7, so that the first sampling bridge 12 and the second sampling bridge 13 form parallel connection in circuit connection relation; the arrangement quantity and the physical parameters of the alloy bridges 11 can be comprehensively determined according to the capacity of the electric meter, when the resistance determined by the physical parameters and the materials of the alloy bridges 11 is smaller, the current which can flow through the alloy bridges 11 is larger, namely the combination and the collocation of the multiple alloy bridges 11 can be suitable for the electric meters with different capacities, and the modular manufacturing is convenient, for example, the specification of the access conductor 7 can be divided into three-phase use and single-phase use according to different voltages, and multiple specifications suitable for different current fluxes are respectively set for two conditions, the alloy bridges 11 can be set into a single specification, and the corresponding matching installation quantity is determined according to the specification of the access conductor 7; the alloy bridges 11 may also be provided with a plurality of specifications such that increasing the number of alloy bridges 11 enables the current flux to increase in a power function manner, for example, the length of the second sampling bridge 13 is equal to the length of the first sampling bridge 12, the cross-sectional area of the second sampling bridge 13 is in a first proportion to the cross-sectional area of the first sampling bridge 12, the current flux of the second sampling bridge 13 is in a second proportion to the current flux of the first sampling bridge 12, and the second proportion is equal to the first proportion in the case that other conditions are consistent.

In order to facilitate installation and arrangement, the input end 8 and the output end 9 of the sampling circuit 6, which are connected with the conductor 7, are configured to be mutually symmetrical structures, the input end 8 and the output end 9 are configured to be holes 10 used for matching with the electric meter terminal 1, and the holes 10 are configured to be circular, so that the holes 10 can be quickly installed with the electric meter terminal 1; a plurality of alloy bridges 11 are arranged between the input end 8 and the output end 9 in a parallel equidistant mode, the arrangement direction of the alloy bridges 11 is perpendicular to the arrangement direction of the access conductor 7, the cross section of each alloy bridge 11 can be configured into a circle or a polygon, the arrangement volume of the sampling circuit 6 in the electricity meter is reduced, the access conductor 7 and the alloy bridges 11 can also be configured into rectangular sheets with the thickness smaller than the length and the width, the alloy bridges 11 and the access conductor 7 of the rectangular sheet structures can be conveniently processed, the isolation structures among the sampling circuits 6 of all phases are convenient to arrange, on the basis of ensuring the collection of electrical parameters, the volume requirement of the device is reduced, and the device is suitable for miniaturization, integration and modularized installation of the electricity meter.

Preferably, as shown in fig. 2, the sampling circuit 6 is configured with a first detection position 14 for monitoring the voltage formed by the current of each alloy bridge 11 of each phase, the first detection position 14 includes a plurality of measurement points arranged on the alloy bridge 11, and the measurement points can be arranged symmetrically with respect to the center line of the alloy bridge 11 or arranged in a centrosymmetric manner with respect to the center point of the alloy bridge 11, so that the measurement points of the first detection position 14 can accurately monitor and sample the voltage data of the alloy bridge 11; the sampling circuit 6 is further provided with a second detection site 15 for monitoring the voltage of the access conductor 7, the detection point of the second detection site 15 being arranged on the input end 8 of the access conductor 7.

Preferably, as shown in fig. 1 to 3, the sampling circuit 6 passes several voltage signals or current signals of each phase to the signal processing circuit 16 for the superposition processing and the analog-to-digital conversion processing. Specifically, for the a phase, the B phase and the C phase, the first detection bit 14 obtains bridge circuit voltages IL1 and IL2 of the plurality of alloy bridges 11 through the measurement points arranged on the alloy bridges 11, and the plurality of bridge circuit voltages IL1 and IL2 are used as input signals of the signal processing circuit 16; the second detection bit 15 obtains an access voltage N for each phase through a measuring point provided at the access conductor 7 for the a-phase, B-phase, C-phase, and N-phase, the access voltage N being an input signal of the signal processing circuit 16.

The signal processing circuit 16 comprises a superposition circuit and an analog-to-digital conversion circuit, wherein the superposition circuit is provided with an adder U1, and the analog-to-digital conversion circuit is provided with an analog-to-digital converter; bridge circuit voltages IL1 and IL2 are used as input signals of the integrator U1, a port 2 and a port 5 of the adder U1 are respectively connected with a power supply end and a grounding end, and the IL1 and the IL2 are respectively connected with a resistor and then are connected to a port 3 of the adder U1; IA + and IA-output by the superposition circuit are used as input signals of an analog-to-digital converter, and IH1 output by the superposition circuit is used as an input signal of a non-full wave identification circuit 18; UA1+ and UA 1-output by the superposition circuit are used as input signals of the analog-to-digital converter; the model of the analog-to-digital converter can be selected from CS5361, the conversion rate is 196kHz, the dynamic range is 114Db, and the requirement of measurement sampling conversion can be met.

Preferably, as shown in fig. 4, IH1 output by the superimposing circuit is used as an input signal of the non-full-wave identifying circuit 18, the non-full-wave identifying circuit 18 is configured with an integrator U12B and an amplifier U12A, wherein the cutoff frequency of the integrator U12B is less than 16kHz, the input signal IH1 is connected to the port 5 and the port 6 of the integrator U12B, the output port 7 is connected to the port 2 and the port 1 of the amplifier U12A, when the input signal IH1 is interrupted, the port 7 of the integrator U12B outputs a spike signal, which is used as an input signal of the amplifier U12A, the output signal det1 of the amplifier U12A is used as a driving signal of the optical coupler, and the driving signal of the optical coupler is transmitted to the controller 17; the non-full wave identification driving signal trigger controller 17 which is detected by the phase splitting carries out non-full wave identification on the current sampling data, namely when the sampling value is distributed in a single polarity, the circuit at the moment can be judged to be non-full wave power utilization, the identification accuracy can be improved, and the software calculation can be simplified to improve the reliability of the system; the type of the optical coupler is EL816, the transmission delay is less than 10us, and the transmission requirement of a control signal can be met.

Preferably, the system supplies power to the signal processing circuit 16 and the non-full wave identification circuit 18 of each phase individually, realizes energy and signal transmission in a multi-path magnetic, field and optical isolation mode, and can complete sampling, processing and conversion of single-phase current and voltage signals and identification of non-full wave signals for the sampling circuit 6, the signal processing circuit 16 and the non-full wave identification circuit 18 of each phase. Specifically, the digital isolator CA-IS3640 has four forward channels, which may respectively supply power to the sampling circuit 6, the signal processing circuit 16, and the non-full-wave identification circuit 18 of a/B/C/N phases in the three-phase electric meter, and the controller 17 IS respectively connected to the signal processing circuit 16 and the non-full-wave identification circuit 18, so that the controller 17 can perform power supply management based on an integrated CA-IS3640 chip, for example, as shown in fig. 3 to 4, the port 5 of the adder U1 of the signal processing circuit 16, the port 3 of the amplifier U12A of the non-full-wave identification circuit 18, the port 5 of the integrator U12B, and the controller 17 are respectively connected to the output end of the digital isolator CA-IS3640 for the same phase, so that the sampling circuit 6, the signal processing circuit 16, the controller 17, and the non-full-wave identification circuit 18 for the single phase of the electric meter can obtain power supply of the digital isolator CA-IS3640, and the specifically adopted digital isolator chip IS CA-IS a type 3640, the maximum output current 20mA, the maximum transfer rate IS 150Mbps, and the analog-to-digital conversion rate of the analog-to-digital converter IS greater than the analog-to-digital converter; the method has 1ns pulse width distortion, 2ns propagation delay deviation, wide input voltage range: 3V-5.5V, wide working temperature range: 40-125 degrees, integrated with high efficiency DC-DC converter and on-chip transformer, optional output voltage: the 3.3V or 5.0V soft start circuit is built in to prevent surge current and output overshoot, and the soft start circuit has overload and short circuit protection functions, an overheat turn-off protection function, excellent electromagnetic compatibility (EMC), low radiation and excellent isolation performance, the isolation voltage is up to 5kV-RMS, the service life of the isolation gate is more than 40 years, and the RoHS packaging standard is met. Therefore, the system independently supplies power to the circuit of each phase through the digital isolator CA-IS3640 and realizes the energy signal transmission of magnetic field optical isolation based on a physical circuit separation mode.

Preferably, in order to realize three-phase synchronous sampling, the main clock signals adopted by the sampling circuit 6, the signal processing circuit 16 and the non-full-wave identification circuit 18 for each phase are uniformly provided by the controller 17, so that the sampling calculation accuracy can be further improved, the system can calculate split-phase voltage, current, power and electric energy of the digital signals obtained by three-way sampling, and can also perform phase combination calculation to obtain high-quality electric energy metering data; the controller 17 is integrated with a clock module, and the clock module provides a main clock signal to a circuit provided for each phase through a connection structure of the controller 17 to realize synchronous sampling of three phases; the controller 17 is also connected with a communication module 19, the communication module 19 can transmit data or receive instructions in a wireless or wired mode, so that the controller 17 can transmit electric energy metering data and electricity stealing identification data through the communication module 19, and can also receive instructions of a control center to perform operations such as positioning, circuit breaking, checking prompt and the like.

Preferably, the application can realize the corresponding electricity larceny prevention method based on the electricity larceny prevention system, and the working principle and the steps comprise: the method comprises the steps that a sampling circuit 6, a signal processing circuit 16 and a non-full-wave identification circuit 18 are arranged for each phase of the ammeter, and the signal processing circuit 16 comprises a superposition circuit and an analog-to-digital conversion circuit; the signal processing circuit 16 and the non-full-wave discrimination circuit 18 are connected to the controller 17 so as to be able to acquire a master clock signal and an independent power supply; the sampling circuit 6 is provided with a multi-channel bridge circuit with a plurality of alloy bridges 11, the sampling circuit 6 can obtain the electrical parameters of each phase, and the electrical parameters at least comprise bridge current/bridge voltage and access voltage of each alloy bridge 11; the sampling circuit 6 transmits the obtained electrical parameters to the signal processing circuit 16, the signal processing circuit 16 comprises a superposition circuit and an analog-to-digital conversion circuit, and the superposition circuit superposes the bridge current/bridge voltage of the plurality of alloy bridges 11 obtained by the sampling circuit 6 based on an adder to obtain single-phase current/unidirectional voltage and non-full-wave identification signals.

The bridge current/bridge voltage obtained by the sampling circuit 6 is processed by the superposition circuit and then respectively output to the non-full wave identification circuit 18 and the analog-to-digital conversion circuit, the access voltage obtained by the sampling circuit 6 is processed by the superposition circuit and then output to the analog-to-digital conversion circuit, and under the condition that the analog-to-digital conversion circuit can convert the single-phase current/unidirectional voltage and the access voltage into digital signals and transmit the digital signals to the controller 17, the controller 17 responds to the digital signals of the analog-to-digital conversion circuit and performs single-phase and phase-combination electric energy metering operation.

In the case where the non-full-wave identifying circuit 18 outputs a drive signal based on the non-full-wave identifying signal and transmits the drive signal to the controller 17, the controller 17 performs non-full-wave identification on the digital signal in response to the drive signal of the non-full-wave identifying circuit 18, and determines that the circuit in which the electricity meter is located is not full-wave electricity when the digital signal sampling value has a unipolar distribution.

For example, taking a three-phase electric meter and 2-way arrangement of the alloy bridge 11 as an example, as shown in fig. 3, the specific structure of the signal processing circuit 16 is as follows: the signal processing circuit 16 includes a superimposing circuit provided with the adder U1 and an analog-to-digital conversion circuit provided with an analog-to-digital converter, and the sampling circuit 6 of each phase delivers an input signal to the superimposing circuit.

For the superimposing circuit, the input signal comprises: for bridge circuit voltages IL1 and IL2 of two alloy bridges 11, a voltage N and an N-phase voltage L1 are accessed, input signals IL1 and IL2 are respectively merged and input to a port 3 of an adder U1 after passing through resistors R3 and R5, a port 4 is connected with the port 1 of the adder, the port 5 and the port 2 of the adder are respectively connected with a power supply and a grounding terminal, so that a plurality of groups of bridge circuit voltages can be superposed based on the action of the adder to obtain the superposed voltage, the output end of the superposed voltage is divided into three output signals, a first output signal IH1 is obtained by connecting output voltages C1 and R1, and IH1 is used as an input signal of a non-full-wave identification circuit 18; the second output signal IA1+ is obtained by connecting a superposed voltage with a resistor R2, and the third output signal IA 1-is obtained by connecting IA1+ with C2, C3, R4 and R6, wherein IA1+ and IA 1-are used as input signals of an analog-to-digital converter; the input signal access voltage N obtains an output signal UA1+ by connecting R7 to R12, and the UA1+ obtains an output signal UA 1-by connecting C4, C5, R13 and R14, wherein the UA1+ and the UA 1-are used as input signals of an analog-to-digital converter; the input signal N-phase voltage L1 is connected with Z1 and grounded; for an analog-to-digital conversion circuit, the input signal comprises: IA1+, IA1-, UA1+ and UA1-, so that the analog signal is converted into a digital signal by an analog-to-digital converter and connected with the controller 17.

For the non-full wave identification circuit 18, as shown in fig. 4, the input signals are IH1, IH1 IS connected to R1 and R2 and IS connected to port 6 of integrator U12B, ih1 IS connected to port 5 of integrator U12B by connecting R1, R14, R9 and C36 arranged in series and parallel, port 7 of integrator U12B IS connected to port 7 by connecting R3 and C24 arranged in parallel to form a feedback loop, so as to realize the integration function of integrator U12B, and the output signal of port 7 IS proportional to the time integration result of input signal IH1, port 5 of integrator U12B IS connected to a reference VREF voltage after resistor R9, and the reference voltage IS provided by digital isolator CA-IS 3640; port 7 of integrator U12B is connected via C39 and R52 to port 2 of amplifier U12A, port 2 is connected via R42 to port 1 of amplifier U12A to form a feedback loop, port 3 of amplifier U12A is connected to a reference voltage, port 1 is connected to R18 and forms an output signal IHDET1, which IHDET1 acts as a drive signal for the opto-coupler and is passed to controller 17.

According to a preferred embodiment, in this embodiment, an improvement is further provided based on the multi-bridge circuit configuration described above. Based on the above, the scheme adopts a multi-bridge circuit mode, so that the current output from the terminal can flow in a plurality of sampling bridges in the same sampling circuit 6, and based on the detection of the electrical parameters of each sampling bridge, the non-full wave identification circuit 18 can judge that the circuit is powered by non-full wave when analyzing the unipolar distribution of the sampling values. Further, based on the parallel multi-bridge sampling circuit 6 structure of the present structure, when receiving a large current in a loop formed by connecting two terminals, each sampling bridge thereof equally divides a certain current, and in general, each sampling bridge equally divides the current, that is, the current on each sampling bridge is ideally consistent. However, on the one hand, the sampling bridges themselves may be different in material, and on the other hand, the sampling bridges themselves may be set to different overcurrent capabilities according to different purposes, because the device is used for connecting to the position of the power transmission end general gate, which generally bears the power output end of the whole user or even the whole user, so that the output current of the power transmission end general gate is generally larger. The signal identification requirement based on non-full-wave power utilization has certain requirements on the accuracy of the electrical parameter sampling value of the sampling bridge, and the accuracy of the electrical parameter acquired by the sampling bridge with high overcurrent capacity is relatively poor, so that fluctuation which can be at least obviously sensed can be generated on the acquired data. In general, the use condition of a municipal power grid at a user end is not constant, and both civil power and commercial power may generate large power consumption fluctuation periodically or aperiodically in certain periods, so that the overcurrent condition of the device is changed, and based on the above, each sampling bridge bears the overcurrent of at least a part of current, but the precision fluctuation of sampling data generated by each sampling bridge under the influence of the overcurrent and the influence of the overcurrent on the service life and the structural strength of the sampling bridge are different.

In view of the above problem, the present embodiment provides a preferred implementation manner, each sampling circuit 6 at least has several sampling bridges, and each sampling bridge is configured to be different from each other at least in the over-voltage parameters and can be adjusted to different over-voltage parameters under specific conditions. There are various optional ways to adjust the over-current parameter of the sampling bridge, wherein, when the over-current parameter mainly passes through the current, the way to adjust the over-current parameter of the sampling bridge may be to adjust the resistance of the sampling bridge, or may be to adjust the pass range of the sampling bridge itself. The resistance of the sampling bridge can be adjusted by, for example, connecting a potentiometer in series on the sampling bridge, where the potentiometer is a device capable of adjusting resistance, and when the potentiometer is connected in series to a sampling bridge loop, the potentiometer can adjust the resistance of the sampling bridge circuit connected in series with the potentiometer, and then based on ohm's law, under the condition that the voltage is relatively fixed, the current can change along with the adjustment of the resistance, and the two are in an anti-correlation relationship. The resistance of the sampling bridge can be adjusted by changing the shape of the sampling bridge, the resistance of the conductor is related to the shape and the material of the sampling bridge, the bearing overcurrent size is related to the material and the shape, and when the material is relatively fixed, the larger the cross-sectional area of the conductor is, the larger the relative resistance is, and the overcurrent capacity is stronger. Further, in the present embodiment, the non-full wave identification circuit 18 is further at least communicatively coupled to a processing unit for receiving the non-full wave identification signal of the non-full wave identification circuit 18 to obtain the identification result of the continuous detection, wherein the processing unit is only configured to obtain the sampling precision of the sampled data. Furthermore, the processing unit forms a sampling precision fluctuation curve based on the sampling precision of the sampling data, confirms the sampling bridge over-current condition of the current data source based on the slope of the current data point position in the curve, and sends an instruction to the sampling bridge over-current parameter adjustment based on the over-current condition. Specifically, the sampling precision fluctuation curve has at least two extension trends, namely upward extension and downward extension, wherein the upward extension represents that the sampling precision is increased, and the downward extension represents that the sampling precision is reduced. Therefore, the result that the current sampling precision fluctuates up and down can be obtained based on the confirmation of the slope of the current data point position, so that the over-current condition of the current sampling bridge is released, and the over-current parameter of the sampling bridge is adjusted based on the over-current condition, so that the over-current of the sampling bridge can be guaranteed to be in a reasonable range while relatively accurate collection electrical parameters are kept. In detail, when the slope of the current data point position is a negative number and has a tendency of continuously increasing towards the negative number at the next moment (namely, when the second-order conductance is positive), the processing unit adjusts the sampling bridge electrical parameter to increase within a first-order range, namely, adjusts in an anti-correlation manner; when the slope of the current data point position is a negative number and the next time has a trend of increment reduction (namely when the second-order conductance is negative), the processing unit adjusts the sampling bridge electrical parameter to reduce in a first-order range, namely adjusts in an anti-correlation mode; when the current data point position slope is positive and the trend of continuously increasing towards the positive is provided at the next moment (namely the second derivative is positive), the processing unit adjusts the sampling bridge electrical parameter to increase in a second-stage range, namely the sampling bridge electrical parameter is adjusted according to a positive correlation mode; when the current data point position slope is a positive number and has a trend of continuously decreasing towards the positive number increment at the next moment (namely when the second derivative is negative), the processing unit adjusts the sampling bridge electrical parameter to decrease in the second-stage range, namely, adjusts according to a positive correlation mode.

Based on the adjustment, the bridge over-current capacity guarantee of the sampler is realized, the accuracy of the sampled data is considered, the sampled data is directly analyzed to form an adjustment decision on the bridge over-current capacity, the adjustment decision can be directly formed at the line level of the sampling circuit 6 more quickly, and the problems of low measurement precision caused by external loop detection, especially inaccurate data caused by sampling bridge loss or sampled data precision loss due to the fact that adjustment cannot be fed back in time are avoided.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims (10)

1. An electricity larceny prevention system for electricity larceny prevention detection and identification of a single-phase, three-phase three-wire or three-phase four-wire electric meter, the system comprising:

the sampling circuit (6) is used for monitoring the electrical parameters of each phase of the electric meter, the sampling circuit (6) is provided with a multi-channel bridge circuit with a plurality of alloy bridges (11), so that the sampling circuit (6) can acquire the electrical parameters of the multi-channel bridge circuit, wherein the electrical parameters at least comprise bridge current/bridge voltage and/or access voltage output by the alloy bridges (11) after linear conversion;

the signal processing circuit (16) is used for carrying out superposition operation and/or analog-to-digital conversion on at least part of the electrical parameters acquired by the sampling circuit (6) and outputting a digital signal and a non-full-wave identification signal;

a non-full-wave identification circuit (18) for performing an integral amplification operation on the non-full-wave identification signal output by the signal processing circuit (16) and outputting a drive signal;

a controller (17) responsive to the digital signal of the signal processing circuit (16), the controller (17) performing single-phase and/or three-phase electric energy metering operation on the circuit;

in the case where the non-full-wave identification circuit (18) outputs the drive signal based on the non-full-wave identification signal and transmits the drive signal to the controller (17), the controller (17) performs non-full-wave identification on the digital signal in response to the drive signal of the non-full-wave identification circuit (18), and determines that the circuit in which the electricity meter is located is not full-wave power when a unipolar distribution occurs in digital signal sampling values.

2. The system of claim 1, wherein the unipolar distribution is a condition that one or more sampling points of the sampling amplitude of the digital signal sampling value before and after the zero crossing of the same cycle are suddenly changed to zero and continuously appear in a set number and above of a cycle range.

3. The system according to claim 1 or 2, wherein the non-full wave identification circuit (18) is further at least communicatively coupled connected to a processing unit for receiving a non-full wave identification signal of the non-full wave identification circuit (18) to obtain a continuously detected identification result, wherein the processing unit is only configured to obtain a sampling accuracy of the sampled data.

4. The system according to any one of the preceding claims 1 to 3, wherein the processing unit forms a sampling precision fluctuation curve based on the sampling precision of the sampled data, confirms the over-current condition of the alloy bridge (11) from which the current data is derived based on the slope of the current data point in the curve, and issues an instruction for adjusting the over-current parameter to the alloy bridge (11) based on the over-current condition.

5. System according to one of the preceding claims 1 to 4, characterized in that the sampling circuit (6) is provided with an access conductor (7) for connection to an electricity meter terminal (1), the access conductor (7) comprising an input (8) and an output (9) arranged separately, the input (8) and the output (9) each establishing a detachable connection with the electricity meter terminal (1), a number of the alloy bridges (11) being arranged in parallel between the input (8) and the output (9), wherein,

the alloy bridges (11) are configured in a structure that is identical or proportional in the over-current parameters and that can be adjusted to different over-current parameters in specific cases.

6. System according to one of the preceding claims 1 to 5, characterized in that, in the case of several of said alloy bridges (11) being connected at both ends by welding or by being integrally formed with the input (8) and output (9) respectively of the access conductor (7), each of said alloy bridges (11) is provided with a first detection bit (14) for monitoring the bridge current or bridge voltage of said alloy bridge (11), wherein,

a plurality of detection points of the first detection position (14) are arranged in an axisymmetric or centrosymmetric manner relative to the alloy bridge (11).

7. The system according to one of the preceding claims 1 to 6, characterized in that the signal processing circuit (16) is configured with a superimposing circuit and an analog-to-digital conversion circuit, the superimposing circuit superimposing the bridge voltage or the bridge current based on an adder and outputting a non-full wave identification signal and an analog signal to the non-full wave identification circuit (18) and the analog-to-digital conversion circuit, respectively.

8. The system according to one of the preceding claims 1 to 7, characterized in that the analog-to-digital conversion circuit converts the analog signal input by the superposition circuit into a digital signal and passes the digital signal to the controller (17), wherein the controller (17) is configured with a clock module which provides a master clock signal for realizing synchronous sampling to the sampling circuit (6), the signal processing circuit (16) and the non-full wave identification circuit (18) via the controller (17).

9. An electricity stealing prevention method, characterized in that it is implemented based on a system as claimed in one of the preceding claims 1 to 8, and in that it comprises the following steps:

setting a sampling circuit (6), a signal processing circuit (16) and a non-full wave identification circuit (18) for each phase of the electric meter;

the sampling circuit (6) is provided with a multi-channel bridge circuit with a plurality of alloy bridges (11), the sampling circuit (6) can acquire electrical parameters of each phase, and the electrical parameters at least comprise bridge current/bridge voltage and access voltage of each alloy bridge (11);

at least part of the electrical parameters acquired by the sampling circuit (6) are subjected to superposition operation and/or analog-to-digital conversion, digital signals and non-full-wave identification signals are output, and a controller (17) is used for performing single-phase and phase-combination electric energy metering operation in response to the digital signals;

under the condition that the non-full-wave identification circuit (18) outputs a driving signal based on a non-full-wave identification signal and transmits the driving signal to the controller (17), the controller (17) performs non-full-wave identification on the digital signal in response to the driving signal of the non-full-wave identification circuit (18), and when a unipolar distribution occurs in digital signal sampling values, the circuit where the electricity meter is located is judged to be non-full-wave electricity utilization.

10. The system of claim 9, wherein the method further comprises one or more of the following steps:

the unipolar distribution is the condition that one or more sampling points of the sampling amplitude of the digital signal sampling value before and after the zero crossing of the same cycle are suddenly changed into zero and continuously appear in a set number and more than a cycle range;

the signal processing circuit (16) comprises a superposition circuit and an analog-to-digital conversion circuit, and the signal processing circuit (16) and the non-full-wave identification circuit (18) are connected with the controller (17) in a mode of acquiring a main clock signal and an independent power supply;

the sampling circuit (6) transmits the acquired electrical parameters to the signal processing circuit (16), and the superposition circuit superposes a plurality of bridge currents/bridge voltages of the alloy bridge (11) acquired by the sampling circuit (6) based on an adder to obtain single-phase currents/unidirectional voltages and non-full-wave identification signals;

the bridge circuit current/bridge circuit voltage obtained by the sampling circuit (6) is processed by the superposition circuit and then is respectively output to the non-full-wave identification circuit (18) and the analog-to-digital conversion circuit, the access voltage obtained by the sampling circuit (6) is processed by the superposition circuit and then is output to the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit can convert the single-phase current/unidirectional voltage and the access voltage into digital signals and transmit the digital signals to the controller (17).

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