Shunt electricity larceny prevention device for acquisition terminal

Abstract

The invention relates to the technical field of electric energy metering, and provides a shunt electricity larceny prevention device for an acquisition terminal, which comprises an external mutual inductor secondary circuit wiring, a magnetic core and a signal processing and operation circuit. The magnetic core is composed of a single-power-frequency metering magnetic core and a double-high-frequency magnetic core, and the high-frequency magnetic core comprises a signal injection magnetic core and a signal receiving magnetic core. And the signal processing and operation circuit comprises a power frequency signal detection circuit, a high-frequency signal injection circuit, a high-frequency signal resonance detection circuit and a self-oscillation circuit. The above circuits jointly complete filtering, detection, analysis and processing of signals, and upload the processed signals to an acquisition terminal control center to realize remote monitoring and management. The device can effectively identify various electricity stealing models including a primary side bypass, a secondary side bypass, a secondary side open circuit and secondary side series connection rectification equipment, and has the advantages of high identification precision, strong anti-interference capability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy metering, and in particular to an anti-shunting electricity theft device for a collection terminal. Background Art

[0002] With the in-depth advancement of the construction of energy Internet, energy control, as a control sensor device for trade settlement in the metering system, is being gradually promoted in the power system. It can effectively identify and control abnormal electricity consumption behavior, provide reliable and direct data support for online monitoring, electricity inspection, and fault diagnosis of metering devices, and provide technical means for realizing intelligent diagnosis and comprehensive analysis of the overall electric energy metering device. Existing electric energy metering equipment usually adopts the selection of appropriate CT or PT to transform the load current on the primary circuit to the secondary circuit and connect it to the electric energy meter for metering. The basic principle of electric energy metering is: the product of voltage, current, and power factor. Therefore, illegal users can achieve the purpose of stealing electricity by changing the voltage, current, or power factor connected to the electric energy meter. In the current technology, there are effective solutions for the theft methods such as cutting off voltage and changing the voltage phase relationship. However, the theft method by changing the current of the secondary circuit is concealed, difficult to accurately check, and extremely harmful, which brings huge economic losses to the country.

[0003] At present, the commonly used electricity theft models can be divided into four categories: 1. Short-circuit the primary terminal of the external transformer of the collector; 2. Short-circuit the secondary terminal of the external transformer of the collector; 3. Open or virtual connection of the secondary terminal of the external transformer of the collector; 4. Connect the rectification equipment in series with the secondary terminal of the external transformer of the collector to steal electricity. For the above electricity theft models, the existing mainstream technical solutions are listed as follows: 1. The signal transceiver circuit of the H-bridge driving transformer couples the high-frequency signal to the high-frequency magnetic core through the H-bridge circuit, and samples the signal received through another high-frequency magnetic core coupling to realize the impedance analysis of the secondary side of the external transformer of the collector, and determine the electricity theft model according to the impedance threshold partition. The disadvantage of this solution is that the high-frequency signal coupling and transceiver process has poor anti-interference ability and is easily interfered by high-frequency clutter in the power frequency environment. Therefore, the impedance threshold partition determination is prone to deviation and the recognition accuracy is low. Second, directly sample the virtual impedance size of the secondary side terminals of the external current transformer of the collector. The disadvantage of this solution is that it cannot identify the power theft model of the rectifier equipment connected in series on the secondary side of the external current transformer of the collector and the power theft model of the primary side bypass of the external current transformer of the collector.

[0004] The technical problems existing in the prior art are summarized as follows: the electricity theft method by changing the shunt current of the metering secondary circuit is extremely concealed and difficult to accurately detect, causing huge economic losses to the country and threatening the safe and stable operation of the power system; at the same time, when using the H-bridge to drive the signal transmission and reception circuit of the transformer, the high-frequency signal is easily interfered by the high-frequency clutter in the power frequency environment during the coupling transmission and reception process, resulting in impedance threshold partition judgment deviation, reducing the accuracy and reliability of electricity theft identification; in addition, the method of directly sampling the virtual impedance size of the secondary terminal of the current transformer cannot identify the series rectifier equipment and the primary side bypass electricity theft model, and there is a security loophole; moreover, the existing electricity metering equipment and technical means have obvious limitations in dealing with complex electricity theft behaviors, and it is difficult to effectively ensure the accuracy and fairness of electricity metering; most importantly, there is a lack of high-precision, multi-functional anti-electricity theft devices on the market that can integrate multiple functional modules and achieve high-precision monitoring and identification.

[0005] Therefore, it is of great significance to design an anti-shunt electricity theft device for a collection terminal to solve the above problems. Summary of the invention

[0006] In order to solve the problems existing in the background technology, the present invention provides an anti-shunt electricity theft device for a collection terminal, which includes:

[0007] Magnetic core and signal processing and operation circuits;

[0008] The magnetic core comprises a single-frequency measurement magnetic core and a dual-high-frequency magnetic core, and the dual-high-frequency magnetic core comprises a signal injection magnetic core and a signal receiving magnetic core;

[0009] The signal processing and operation circuit includes a power frequency signal detection circuit, a high frequency signal injection circuit, a high frequency signal resonance detection circuit, and a self-excited oscillation circuit composed of a NOT gate.

[0010] The single-frequency metering core and the double-high-frequency core are connected to the secondary circuit wiring of the external transformer;

[0011] The signal processing and operation circuit is connected to the magnetic core through multiple interfaces, including:

[0012] The power frequency signal detection circuit is connected to the sampling interface of the single power frequency metering magnetic core to detect the power frequency signal;

[0013] The high-frequency signal injection circuit is connected to the signal injection magnetic core in the dual high-frequency magnetic core, and a high-frequency signal is generated and injected through the circuit;

[0014] The resonant detection circuit of the high-frequency signal is connected to the signal receiving magnetic core in the double high-frequency magnetic core to receive and detect the high-frequency signal coupled back;

[0015] The self-excited oscillation circuit indirectly receives and processes the signal from the magnetic core through the signal processing and operation circuit to perform state recognition;

[0016] The power frequency signal detection circuit, the high frequency signal injection circuit, the high frequency signal resonance detection circuit and the self-excited oscillation circuit are interconnected inside the signal processing and operation circuit to jointly complete the signal filtering, detection, analysis and processing;

[0017] The processed signal, i.e. the electricity theft model identification result, is uploaded to the acquisition terminal control center through the communication interface at regular intervals to achieve remote monitoring and management.

[0018] In the preferred solution, the power frequency signal detection circuit includes a power frequency sampling interface IN1, the power frequency sampling interface IN1 is connected to a resistor R1, the other end of R1 is connected to a resistor R2 and a capacitor C2, the other end of R2 is connected to a capacitor C1 and an op amp U1-3, the other end of C1 is connected to GND, the other end of C2 is connected to U1-1, a resistor R4, a capacitor C4 and a capacitor C5, a resistor R3 is connected to U1-4 and the other end of resistor R4, the other end of R3 is connected to GND, the other end of C4 is connected to a resistor R5 and an op amp U2-3, the other end of R5 is connected to a reference voltage Vref, U2-4 is connected to a resistor R7 and a resistor R8, and the other end of R7 is connected to Connect capacitor C6, the other end of C6 is connected to GND, the other end of R8 is connected to U1-1 and resistor R10, the other end of R10 is connected to capacitor C7 and signal output OUT1, the other end of C7 is connected to GND, the other end of C5 is connected to resistor R6 and op amp U3-3, the other end of R6 is connected to capacitor C3 and reference voltage Vref, the other end of C3 is connected to GND, U3-4 is connected to U3-1 and resistor R9, the other end of R9 is connected to output signal OUT2, +VCC is connected to U1-5, -VCC is connected to U1-2, VDD is connected to U2-5 and U3-5, GND is connected to U2-2 and U3-2.

[0019] In a preferred embodiment, the high-frequency signal injection circuit includes an input signal IN2, which is connected to one end of a resistor R13, and the other end of R13 is connected to a resistor R14, a capacitor C9, and an op amp U4-4. VDD is connected to a resistor R11, and the other end of R11 is connected to a capacitor C8, a resistor R12, and U4-3. The other end of C8 is connected to GND, and the other end of R12 is connected to GND. U4-1 is connected to the other end of R14, the other end of C9, and a capacitor C11. The other end of C11 is connected to a resistor R15 and an op amp U5-3, and the other end of R15 is connected to GND. U5-4 is connected to U5-1, and an output signal OUT3 is provided. +VCC is connected to capacitors C10, U4-5, capacitors C12, and U5-5. The other end of C10 is connected to GND, and the other end of C12 is connected to GND. -VCC is connected to capacitors C13 and U5-2, and the other end of C13 is connected to GND, and U4-2 is connected to GND.

[0020] In the preferred embodiment, the resonance detection circuit of the high-frequency signal includes a high-frequency coupling signal IN3, the high-frequency coupling signal IN3 is connected to the capacitor C14, the other end of C14 is connected to the capacitor C15 and the resistor R16, the other end of C15 is connected to the resistor R17 and the operational amplifier U6-3, the other end of R17 is connected to GND, the other end of R16 is connected to U6-1, the capacitor C16 and the resistor R19, the other end of R19 is connected to the resistor R18 and U6-4, the other end of R18 is connected to GND, the other end of C16 is connected to the capacitor C17 and the resistor R21, and the other end of C17 is connected to the resistor R20 , op amp U7-3, the other end of R20 is connected to GND, the other end of R21 is connected to U7-1, resistor R24, resistor R23, the other end of R23 is connected to resistor R22, U7-4, the other end of R22 is connected to GND, the other end of R24 is connected to capacitor C18, resistor R25, the other end of R25 is connected to capacitor C19, op amp U8-3, the other end of C19 is connected to GND, the other end of C18 is connected to U8-1, resistor R28, resistor R27, the other end of R27 is connected to resistor R26, U8-4, the other end of R26 is connected to GND, R28 is connected to GND. One end is connected to resistor R29 and resistor R30, the other end of R29 is connected to capacitor C20, op amp U9-4, capacitor C21, the other end of C20 is connected to GND, the other end of R30 is connected to U9-1, the other end of capacitor C21, capacitor C22, capacitor C23, U9-3 is connected to GND, the other end of C22 is connected to resistor R32 and op amp U10-3, the other end of R32 is connected to Vref, U10-4 is connected to resistor R33 and resistor R34, the other end of R33 is connected to capacitor C24, the other end of C24 is connected to GND, the other end of R34 is connected to U1 0-1, resistor R35, the other end of R35 is connected to the output signal OUT4, the other end of C23 is connected to resistor R31, op amp U11-3, the other end of R31 is connected to Vref, U11-4 is connected to U11-1, resistor R36, the other end of R36 is connected to the output signal OUT5, +VCC is connected to U6-5, U7-5, U8-5, U9-5, -VCC is connected to U6-2, U7-2, U8-2, U9-2, VDD is connected to U10-5, U11-5, U10-2 is connected to GND, and U11-2 is connected to GND.

[0021] In the preferred scheme, the self-excited oscillation circuit composed of a NOT gate has a high-frequency coupling signal IN4+ and a high-frequency coupling signal IN4-, and the high-frequency coupling signal IN4+ is connected to a resistor R37, a capacitor C26, and inverters U12-1 and U12-6, and one end of C26 is connected to GND, and the high-frequency coupling signal IN4- is connected to a resistor R38, a capacitor C27, and an inverter U12-3, and one end of C27 is connected to GND, and a capacitor C25 is connected to the other end of R37 and the other end of R38, and the other end of C25 is connected to GND, and U12-2 is connected to GND, and the input control signal IN5 is connected to a resistor R40, and the other end of R40 is connected to a transistor Q1-b, and Q1-e is connected to VDD, and Q1-c is connected to capacitors C28 and U12-5, and the other end of C28 is connected to GND, and U12-4 is connected to a resistor R39, and the other end of R39 is connected to the output signal OUT6.

[0022] The beneficial effects achieved by the present invention are:

[0023] The present invention integrates multiple functional modules such as power frequency metering, high-frequency signal injection and detection, and self-excited oscillation detection, and realizes comprehensive and high-precision monitoring of the external current loop of the acquisition terminal. Through the carefully designed power frequency signal detection circuit, high-frequency signal injection circuit, high-frequency signal resonance detection circuit, and self-excited oscillation circuit composed of non-gates, it not only ensures the accurate detection of power frequency signals, but also realizes flexible injection and efficient detection of high-frequency signals, and uses self-excited oscillation circuits to assist in state identification. The anti-interference ability of the device is significantly improved, ensuring the accuracy and reliability of identifying electricity theft. The device has significant advantages such as multi-functional integration, high-precision identification, strong anti-interference ability, flexibility and scalability, and has demonstrated strong core competitiveness in the field of electric energy metering and anti-electricity theft, providing a strong guarantee for the safe and stable operation of the power system.

[0024] The present invention can identify various electricity theft models with high precision, including primary side bypass, secondary side bypass, secondary side open circuit, secondary side series rectifier equipment, etc., through the cooperation of dual high-frequency magnetic cores and signal processing and operation circuits. Through filtering, amplification and other processing in the signal processing and operation circuit, the anti-interference ability of the signal is improved, and the accuracy and reliability of identification are ensured. Through the carefully designed power frequency signal detection circuit, the power frequency signal can be accurately detected and processed, providing reliable data support for subsequent analysis. The high-frequency signal injection circuit can generate and inject high-frequency signals of different frequencies and amplitudes as needed, providing a diversified signal source for electricity theft detection. Through the resonance detection circuit of the high-frequency signal, the high-frequency signal coupled back can be efficiently received and detected, providing an important basis for the analysis of electricity theft behavior. The self-excited oscillation circuit composed of the NOT gate can generate a stable oscillation signal, the frequency and amplitude of which are closely related to the state of the current loop, providing a powerful auxiliary means for state identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a structural block diagram of the working relationship of an anti-shunt electricity theft device used in a collection terminal.

[0026] Figure 2 It is a structural diagram of the industrial frequency signal detection circuit of the present invention.

[0027] Figure 3 This is a structural diagram of the high-frequency signal injection circuit of the present invention.

[0028] Figure 4 This is the structural diagram of the resonance detection circuit for high-frequency signals.

[0029] Figure 5 This is a structural diagram of a self-excited oscillation circuit composed of a NOT gate. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative, and the present invention is not limited to the various structures recorded in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0031] Reference Figure 1 , the present invention provides an anti-shunt electricity theft device for a collection terminal, which includes a magnetic core and a signal processing and operation circuit;

[0032] The magnetic core comprises a single-frequency measurement magnetic core and a dual-high-frequency magnetic core, and the dual-high-frequency magnetic core comprises a signal injection magnetic core and a signal receiving magnetic core;

[0033] The signal processing and operation circuit includes a power frequency signal detection circuit, a high frequency signal injection circuit, a high frequency signal resonance detection circuit and a self-excited oscillation circuit composed of a NOT gate.

[0034] The single-frequency metering core and the double-high-frequency core are connected to the secondary circuit wiring of the external transformer;

[0035] The signal processing and operation circuit is connected to the magnetic core through multiple interfaces, including:

[0036] The power frequency signal detection circuit is connected to the sampling interface of the single power frequency metering magnetic core to detect the power frequency signal;

[0037] The high-frequency signal injection circuit is connected to the signal injection magnetic core in the dual high-frequency magnetic core, and a high-frequency signal is generated and injected through the circuit;

[0038] The resonant detection circuit of the high-frequency signal is connected to the signal receiving magnetic core in the double high-frequency magnetic core to receive and detect the high-frequency signal coupled back;

[0039] The self-excited oscillation circuit indirectly receives and processes the signal from the magnetic core through the signal processing and operation circuit to perform state recognition;

[0040] The power frequency signal detection circuit, the high frequency signal injection circuit, the high frequency signal resonance detection circuit and the self-excited oscillation circuit are interconnected inside the signal processing and operation circuit to jointly complete the signal filtering, detection, analysis and processing;

[0041] The processed signal, i.e. the electricity theft model identification result, is uploaded to the acquisition terminal control center through the communication interface at regular intervals to achieve remote monitoring and management.

[0042] Figure 2 The power frequency signal detection circuit of the present invention is shown, the power frequency sampling interface IN1 is connected to the resistor R1, the other end of R1 is connected to the resistor R2 and the capacitor C2, the other end of R2 is connected to the capacitor C1 and the operational amplifier U1-3, the other end of C1 is connected to GND, the other end of C2 is connected to U1-1, the resistor R4, the capacitor C4 and the capacitor C5, the resistor R3 is connected to U1-4 and the other end of the resistor R4, the other end of R3 is connected to GND, the other end of C4 is connected to the resistor R5 and the operational amplifier U2-3, the other end of R5 is connected to the reference voltage Vref, U2-4 is connected to the resistor R7 and the resistor R8, and the other end of R7 is connected to the capacitor C6 , the other end of C6 is connected to GND, the other end of R8 is connected to U1-1 and resistor R10, the other end of R10 is connected to capacitor C7 and signal output OUT1, the other end of C7 is connected to GND, the other end of C5 is connected to resistor R6 and operational amplifier U3-3, the other end of R6 is connected to capacitor C3 and reference voltage Vref, the other end of C3 is connected to GND, U3-4 is connected to U3-1 and resistor R9, the other end of R9 is connected to output signal OUT2, +VCC is connected to U1-5, -VCC is connected to U1-2, VDD is connected to U2-5 and U3-5, GND is connected to U2-2 and U3-2. Among them, the parameters of resistors R1 and R2, capacitors C1 and C2 can be adjusted, the cutoff frequency of the second-order low-pass filter of the voltage-controlled voltage source can be adjusted, and the filtering depth can be adjusted. Adjust the ratio of R7 and R8 to adjust the voltage amplification factor of the integrated operational amplifier circuit to achieve an ideal power frequency signal recognition effect;

[0043] Figure 3The high-frequency signal injection circuit of the present invention is shown, the input signal IN2 is connected to the resistor R13, the other end of R13 is connected to the resistor R14, the capacitor C9, and the operational amplifier U4-4, VDD is connected to the resistor R11, the other end of R11 is connected to the capacitor C8, the resistor R12, and U4-3, the other end of C8 is connected to GND, the other end of R12 is connected to GND, U4-1 is connected to the other end of R14, the other end of C9, and the capacitor C11, and the other end of C11 is connected to the resistor R15, the operational amplifier U5-3, R15 The other end is connected to GND, U5-4 is connected to U5-1, output signal OUT3, +VCC is connected to capacitor C10, U4-5, capacitor C12, U5-5, the other end of C10 is connected to GND, the other end of C12 is connected to GND, -VCC is connected to capacitor C13, U5-2, the other end of C13 is connected to GND, and U4-2 is connected to GND; Among them, the input signal IN2 can adjust the idle and hetero-frequency signal transmission interval, and can set the hetero-frequency signal sweep round and different frequency modulation strategies. Adjust the ratio of R13 and R14 to adjust the error amplification factor of the differential operational amplifier circuit to achieve the ideal hetero-frequency signal injection effect.

[0044] Figure 4The high-frequency signal resonance detection circuit of the present invention is shown, the high-frequency coupling signal IN3 is connected to the capacitor C14, the other end of C14 is connected to the capacitor C15 and the resistor R16, the other end of C15 is connected to the resistor R17 and the operational amplifier U6-3, the other end of R17 is connected to GND, the other end of R16 is connected to U6-1, the capacitor C16 and the resistor R19, the other end of R19 is connected to the resistor R18 and U6-4, the other end of R18 is connected to GND, the other end of C16 is connected to the capacitor C17 and the resistor R21, the other end of C17 is connected to the resistor R20 and the operational amplifier U7-3, The other end of R20 is connected to GND, the other end of R21 is connected to U7-1, resistor R24, and resistor R23, the other end of R23 is connected to resistor R22 and U7-4, the other end of R22 is connected to GND, the other end of R24 is connected to capacitor C18 and resistor R25, the other end of R25 is connected to capacitor C19 and op amp U8-3, the other end of C19 is connected to GND, the other end of C18 is connected to U8-1, resistor R28, and resistor R27, the other end of R27 is connected to resistor R26 and U8-4, the other end of R26 is connected to GND, and the other end of R28 is connected to capacitor C19 and op amp U8-3. Resistor R29, resistor R30, the other end of R29 is connected to capacitor C20, op amp U9-4, capacitor C21, the other end of C20 is connected to GND, the other end of R30 is connected to U9-1, the other end of capacitor C21, capacitor C22, capacitor C23, U9-3 is connected to GND, the other end of C22 is connected to resistor R32, op amp U10-3, the other end of R32 is connected to Vref, U10-4 is connected to resistor R33, resistor R34, the other end of R33 is connected to capacitor C24, the other end of C24 is connected to GND, the other end of R34 is connected to U10- 1. Resistor R35, the other end of R35 is connected to the output signal OUT4, the other end of C23 is connected to resistor R31, op amp U11-3, the other end of R31 is connected to Vref, U11-4 is connected to U11-1, resistor R36, the other end of R36 is connected to the output signal OUT5, +VCC is connected to U6-5, U7-5, U8-5, U9-5, -VCC is connected to U6-2, U7-2, U8-2, U9-2, VDD is connected to U10-5, U11-5, U10-2 is connected to GND, and U11-2 is connected to GND. Among them, the parameters such as resistors R16, R17, R20, R21, R24, R25, capacitors C14, C15, C16, C17, C18, C19 can be adjusted to adjust the cutoff frequency of the second-order high-pass filter and the voltage-controlled voltage source second-order low-pass filter, and adjust the filtering depth. Adjust the ratio of R33 and R34 to adjust the voltage amplification factor of the integrated operational amplifier circuit to achieve the ideal hetero-frequency signal recognition effect;

[0045] Figure 5The self-excited oscillation circuit composed of a NOT gate of the present invention is shown, the high-frequency coupling signal IN4+ is connected to a resistor R37, a capacitor C26, and inverters U12-1 and U12-6, one end of C26 is connected to GND, the high-frequency coupling signal IN4- is connected to a resistor R38, a capacitor C27, and an inverter U12-3, one end of C27 is connected to GND, the capacitor C25 is connected to the other end of R37 and the other end of R38, the other end of C25 is connected to GND, U12-2 is connected to GND, the input control signal IN5 is connected to a resistor R40, the other end of R40 is connected to a transistor Q1-b, Q1-e is connected to VDD, Q1-c is connected to capacitors C28 and U12-5, the other end of C28 is connected to GND, U12-4 is connected to a resistor R39, and the other end of R39 is connected to the output signal OUT6; wherein, the switching state of the input control signal IN5 can be set to adjust the cut-in state of the self-excited oscillation circuit and the high-frequency signal resonance detection circuit.

[0046] The anti-shunt electricity theft device for a collection terminal of the present invention has a working process involving the close cooperation of the secondary circuit wiring of the external transformer, the magnetic core, and the signal processing and operation circuit. The following is its detailed working process:

[0047] 1. Initial stage of current signal introduction and processing;

[0048] The current in the power system is transformed through an external transformer, which proportionally reduces the large current on the primary side to a small current on the secondary side.

[0049] The secondary circuit wiring of the external transformer introduces this reduced current signal into the anti-shunt power theft device.

[0050] The introduced current signal first passes through the single-frequency measuring magnetic core. The magnetic core generates corresponding magnetic field changes according to the changes in current, realizing the conversion of current signal into magnetic field signal.

[0051] At the same time, the signal injection core in the dual high-frequency core is ready to receive the high-frequency signal from the high-frequency signal injection circuit and couple it to the secondary circuit of the external transformer.

[0052] 2. Signal processing and operation stage;

[0053] The power frequency signal detection circuit receives the magnetic field signal (ie, the power frequency signal) output by the single power frequency metering magnetic core through a sampling interface.

[0054] The signal is filtered, amplified, and processed to improve the signal-to-noise ratio and stability of the signal, and the processed signal is output to the subsequent circuit.

[0055] The high-frequency signal injection circuit generates a high-frequency signal of preset frequency and amplitude, and couples the high-frequency signal into the secondary circuit of the external transformer through the signal injection magnetic core.

[0056] When a high-frequency signal propagates in a loop, it interacts with the impedance in the loop to form a high-frequency signal that is coupled back.

[0057] The signal receiving magnetic core receives the coupled high frequency signals and outputs them to the resonant detection circuit of the high frequency signal.

[0058] The resonance detection circuit of the high-frequency signal performs resonance detection on the received high-frequency signal and analyzes the characteristics of the signal such as frequency, amplitude and phase.

[0059] These characteristics can be used to determine whether there is an abnormal state in the current loop, such as power theft.

[0060] The self-excited oscillation circuit composed of the NOT gate generates a stable oscillation signal, the frequency and amplitude of which are related to the state of the current loop.

[0061] By analyzing the characteristics of the oscillation signal, it is possible to further assist in identifying abnormal conditions in the current loop.

[0062] 3. Comprehensive analysis and result uploading stage;

[0063] The signal processing and operation circuit comprehensively analyzes the output signals of the power frequency signal detection circuit, the high frequency signal resonance detection circuit and the self-excited oscillation circuit.

[0064] Through complex algorithms and logical judgments, specific electricity theft models or other abnormal conditions in the current loop can be identified.

[0065] Once an abnormal state is identified, the device will upload the results to the acquisition terminal control center through the communication interface at a regular interval.

[0066] The control center can monitor the status of the current loop in real time and take corresponding measures to deal with it, such as alarming, cutting off power supply, etc.

[0067] The anti-shunt electricity theft device of the present invention introduces current signals through the secondary circuit wiring of an external transformer, uses a magnetic core to couple and transform signals, and then performs complex signal processing and state recognition through a signal processing and operation circuit, ultimately achieving accurate monitoring of the current circuit state and timely detection and processing of abnormal states.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preventing electricity theft from being shunted for a collection terminal, characterized in that: It includes a magnetic core and a signal processing and operation circuit, wherein: The magnetic core comprises a single-frequency measurement magnetic core and a dual-high-frequency magnetic core, and the dual-high-frequency magnetic core comprises a signal injection magnetic core and a signal receiving magnetic core; The signal processing and operation circuit includes a power frequency signal detection circuit, a high frequency signal injection circuit, a high frequency signal resonance detection circuit, and a self-excited oscillation circuit composed of a NOT gate. The single-frequency metering core and the double-high-frequency core are connected to the secondary circuit wiring of the external transformer; The signal processing and operation circuit is connected to the magnetic core through multiple interfaces, including: The power frequency signal detection circuit is connected to the sampling interface of the single power frequency metering magnetic core to detect the power frequency signal; The high-frequency signal injection circuit is connected to the signal injection magnetic core in the dual high-frequency magnetic core, and a high-frequency signal is generated and injected through the circuit; The resonant detection circuit of the high-frequency signal is connected to the signal receiving magnetic core in the double high-frequency magnetic core to receive and detect the high-frequency signal coupled back; The self-excited oscillation circuit indirectly receives and processes the signal from the magnetic core through the signal processing and operation circuit to perform state recognition; The power frequency signal detection circuit, the high frequency signal injection circuit, the high frequency signal resonance detection circuit and the self-excited oscillation circuit are interconnected inside the signal processing and operation circuit to jointly complete the signal filtering, detection, analysis and processing; The processed signal, i.e. the electricity theft model identification result, is uploaded to the acquisition terminal control center through the communication interface at regular intervals to achieve remote monitoring and management.

2. The anti-shunt electricity theft device for a collection terminal according to claim 1, characterized in that: The power frequency signal detection circuit includes a power frequency sampling interface IN1, the power frequency sampling interface IN1 is connected to a resistor R1, the other end of R1 is connected to a resistor R2 and a capacitor C2, the other end of R2 is connected to a capacitor C1 and an op amp U1-3, the other end of C1 is connected to GND, the other end of C2 is connected to U1-1, a resistor R4, a capacitor C4 and a capacitor C5, a resistor R3 is connected to U1-4 and the other end of resistor R4, the other end of R3 is connected to GND, the other end of C4 is connected to a resistor R5 and an op amp U2-3, the other end of R5 is connected to a reference voltage Vref, U2-4 is connected to a resistor R7 and a resistor R8, and the other end of R7 is connected to a capacitor C6, the other end of C6 is connected to GND, the other end of R8 is connected to U1-1 and resistor R10, the other end of R10 is connected to capacitor C7 and signal output OUT1, the other end of C7 is connected to GND, the other end of C5 is connected to resistor R6 and op amp U3-3, the other end of R6 is connected to capacitor C3 and reference voltage Vref, the other end of C3 is connected to GND, U3-4 is connected to U3-1 and resistor R9, the other end of R9 is connected to output signal OUT2, +VCC is connected to U1-5, -VCC is connected to U1-2, VDD is connected to U2-5 and U3-5, and GND is connected to U2-2 and U3-2.

3. The anti-shunt electricity theft device for a collection terminal according to claim 1, characterized in that: The high-frequency signal injection circuit includes an input signal IN2, which is connected to one end of a resistor R13, and the other end of R13 is connected to a resistor R14, a capacitor C9, and an op amp U4-4. VDD is connected to a resistor R11, and the other end of R11 is connected to a capacitor C8, a resistor R12, and U4-3. The other end of C8 is connected to GND, and the other end of R12 is connected to GND. U4-1 is connected to the other end of R14, the other end of C9, and a capacitor C11. The other end of C11 is connected to a resistor R15 and an op amp U5-3, and the other end of R15 is connected to GND. U5-4 is connected to U5-1, and an output signal OUT3 is provided. +VCC is connected to capacitors C10, U4-5, capacitors C12, and U5-5. The other end of C10 is connected to GND, and the other end of C12 is connected to GND. -VCC is connected to capacitors C13 and U5-2, and the other end of C13 is connected to GND, and U4-2 is connected to GND.

4. The anti-shunting electricity theft device for a collection terminal according to claim 1, characterized in that: The resonance detection circuit of the high-frequency signal includes a high-frequency coupling signal IN3, the high-frequency coupling signal IN3 is connected to the capacitor C14, the other end of C14 is connected to the capacitor C15 and the resistor R16, the other end of C15 is connected to the resistor R17 and the operational amplifier U6-3, the other end of R17 is connected to GND, the other end of R16 is connected to U6-1, the capacitor C16 and the resistor R19, the other end of R19 is connected to the resistor R18 and U6-4, the other end of R18 is connected to GND, the other end of C16 is connected to the capacitor C17 and the resistor R21, the other end of C17 is connected to the resistor R20 and the operational amplifier U7 -3, the other end of R20 is connected to GND, the other end of R21 is connected to U7-1, resistor R24, and resistor R23, the other end of R23 is connected to resistor R22 and U7-4, the other end of R22 is connected to GND, the other end of R24 is connected to capacitor C18 and resistor R25, the other end of R25 is connected to capacitor C19 and op amp U8-3, the other end of C19 is connected to GND, the other end of C18 is connected to U8-1, resistor R28, and resistor R27, the other end of R27 is connected to resistor R26 and U8-4, the other end of R26 is connected to GND, and the other end of R28 is connected to Connect resistor R29 and resistor R30. The other end of R29 is connected to capacitor C20, op amp U9-4 and capacitor C21. The other end of C20 is connected to GND. The other end of R30 is connected to U9-1, the other end of capacitor C21, capacitor C22 and capacitor C23. U9-3 is connected to GND. The other end of C22 is connected to resistor R32 and op amp U10-3. The other end of R32 is connected to Vref. U10-4 is connected to resistor R33 and resistor R34. The other end of R33 is connected to capacitor C24. The other end of C24 is connected to GND. The other end of R34 is connected to U10 -1, resistor R35, the other end of R35 is connected to the output signal OUT4, the other end of C23 is connected to resistor R31, op amp U11-3, the other end of R31 is connected to Vref, U11-4 is connected to U11-1, resistor R36, the other end of R36 is connected to the output signal OUT5, +VCC is connected to U6-5, U7-5, U8-5, U9-5, -VCC is connected to U6-2, U7-2, U8-2, U9-2, VDD is connected to U10-5, U11-5, U10-2 is connected to GND, and U11-2 is connected to GND.

5. The anti-shunting electricity theft device for a collection terminal according to claim 1, characterized in that: The self-excited oscillation circuit composed of a NOT gate has a high-frequency coupling signal IN4+ and a high-frequency coupling signal IN4-. The high-frequency coupling signal IN4+ is connected to a resistor R37, a capacitor C26, and inverters U12-1 and U12-6. One end of C26 is connected to GND. The high-frequency coupling signal IN4- is connected to a resistor R38, a capacitor C27, and an inverter U12-3. One end of C27 is connected to GND. The capacitor C25 is connected to the other end of R37 and the other end of R38. The other end of C25 is connected to GND. U12-2 is connected to GND. The input control signal IN5 is connected to a resistor R40. The other end of R40 is connected to a transistor Q1-b. Q1-e is connected to VDD. Q1-c is connected to capacitors C28 and U12-5. The other end of C28 is connected to GND. U12-4 is connected to a resistor R39. The other end of R39 is connected to the output signal OUT6.

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