Monitoring system for replacing intelligent sensor of mutual inductance type electric energy meter without power cut

Abstract

The invention relates to the technical field of intelligent power grid metering operation and maintenance and electrical hot-line work safety monitoring, in particular to a monitoring system for replacing an intelligent sensor of a mutual inductance type electric energy meter without power cut, and the system comprises a non-contact injection and collection module which collects a loop response signal superposed with a non-power-frequency characteristic perturbation signal in real time; the impedance spectrum feature extraction module is used for generating complex impedance data; the topological fingerprint construction module is used for determining a current physical connection state; the logic locking monitoring module is used for executing monitoring logic; the monitoring logic is configured to output an unlocking signal or output a locking alarm signal; according to the invention, the problem of monitoring instrument failure caused by insufficient load current is effectively solved, and the real-time performance and reliability of physical connection monitoring under all working conditions are ensured.

Description

Technical Field

[0001] This invention relates to the field of smart grid metering and maintenance and electrical live-line work safety monitoring technology, specifically a smart sensor monitoring system for uninterrupted replacement of mutual inductance energy meters. Background Technology

[0002] In the environment of uninterrupted replacement and on-site operation and maintenance of mutual inductance energy meters, operators need to perform strict timing wiring operations and status confirmation on the secondary circuits of current transformers and voltage transformers while they are energized. To monitor the physical connection status of these circuits, existing solutions generally adopt a passive monitoring architecture based on power frequency quantities. This involves measuring the load current amplitude in the circuit using general-purpose instruments or relying solely on visual inspection by operators to determine wiring continuity. While this approach has some detection capability under normal scenarios with stable and sufficient load, it is highly dependent on the load energy of the primary side of the power grid. In extreme conditions such as no-load or low-load power grid operation, the instruments may fail due to weak or even missing signals. Furthermore, it is highly susceptible to random fluctuations in load current, leading to misjudgments of short-circuit or open-circuit states. In addition, traditional static continuity detection cannot effectively identify potential loose connections due to dynamic contact instability, such as contact surface oxidation or loose screws. It is also difficult to provide independent and accurate physical connection reliability criteria in complex, high-electromagnetic-interference environments. Therefore, improving the real-time performance, accuracy, and ability to perceive microscopic contact states of secondary circuit physical connection status monitoring without relying on the power grid load and its operating status has become an urgent technical problem to be solved. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a smart sensor monitoring system for uninterrupted replacement of mutual inductance energy meters. Specifically, the technical solution of the present invention includes: The non-contact injection and acquisition module is configured to be snapped into the wiring circuit of the energy meter, inject non-power frequency characteristic perturbation signals into the circuit, and acquire the circuit response signal superimposed with the non-power frequency characteristic perturbation signals in real time. The impedance spectrum feature extraction module is configured to perform complex frequency domain transformation and deconstruction on the loop response signal, filter out power frequency fundamental wave interference, extract the frequency domain response features corresponding to the non-power frequency characteristic perturbation signal, and generate complex impedance data. The topology fingerprint construction module is configured to construct a topology impedance fingerprint characterizing the complex impedance characteristics of the current loop based on the complex impedance data, and map the topology impedance fingerprint to a preset operation timing state matrix to determine the current physical connection state. The logic interlocking monitoring module is configured to acquire standard operating procedure instructions, compare the current physical connection state with the target state corresponding to the standard operating procedure instructions, and execute monitoring logic. The monitoring logic is configured as follows: if the current physical connection state matches the target state corresponding to the standard operation procedure instruction and meets the preset security unlocking conditions, an unlocking signal is output; if the current physical connection state does not match the target state corresponding to the standard operation procedure instruction, does not meet the security unlocking conditions, or the current physical connection state is determined to be a fault state, a lockout alarm signal is output.

[0004] Preferably, the non-contact injection and acquisition module performs the injection and acquisition method including: Drive the high-frequency signal transmitting coil to generate a sine wave or pseudo-random sequence with a frequency in a preset high-frequency range as a non-power frequency characteristic perturbation signal; The principle of magnetic coupling is used to induce non-power frequency characteristic perturbation signals into the current or voltage circuit of the energy meter; A high-sensitivity pickup coil is used to detect composite electromagnetic waves in the circuit, convert the composite electromagnetic waves into analog voltage signals, and perform analog-to-digital conversion to obtain digital circuit response signals.

[0005] Preferably, the method for generating complex impedance data by the impedance spectrum feature extraction module includes: Perform a Fast Fourier Transform on the loop response signal to obtain full-spectrum data; Locate the characteristic frequency points corresponding to non-power frequency characteristic perturbation signals in the full spectrum data; Extract the amplitude and phase information at the characteristic frequency points, and calculate the reflection coefficient of the loop at the characteristic frequency; Based on the reflection coefficient and the preset sensor transfer function, the real part and imaginary part of the complex impedance of the circuit are calculated and combined to form complex impedance data.

[0006] Preferably, the method for constructing a topological impedance fingerprint using the topological fingerprint construction module includes: The real part of the complex impedance is taken as the resistive characteristic component, and the imaginary part of the complex impedance is taken as the inductive / capacitive characteristic component. Construct a two-dimensional impedance eigenvector and use the projection trajectory of the two-dimensional impedance eigenvector on the complex plane as a topological impedance fingerprint; The evolution path of the topological impedance fingerprint in the complex plane is tracked in real time, the rate of change of the evolution path is calculated, and the rate of change is used as the fingerprint stability index.

[0007] Preferably, the method by which the topology fingerprint construction module determines the current physical connection state includes: Access the preset operation timing state matrix, which contains standard fingerprint intervals corresponding to normal operation state, short-circuit transition state and open circuit fault state. Calculate the Euclidean distance between the topological impedance fingerprint and each standard fingerprint interval; The state corresponding to the standard fingerprint interval with the smallest Euclidean distance is determined as the current physical connection state; When the standard operating procedure instruction is to short-circuit the secondary side of the current transformer, the current physical connection state is confirmed to be a reliable short-circuit state only when the topological impedance fingerprint falls into the low impedance closed interval corresponding to the short-circuit transition state and the real part of the complex impedance is less than the preset safe short-circuit threshold.

[0008] Preferably, the method by which the logic-locked monitoring module performs the voltage loop monitoring includes: When the standard operating procedure instruction indicates that voltage loop wiring should be performed, the ground impedance modulus value corresponding to the topological impedance fingerprint should be obtained; If the ground impedance modulus is greater than the preset neutral line connection threshold, it is identified as a neutral line disconnection state, and a blocking alarm signal for phase line connection is output. If the ground impedance modulus is less than or equal to the preset neutral line connection threshold, it is identified as a neutral line connection state, and an unlocking signal for phase line connection is output to force the connection sequence of neutral line first and then phase line.

[0009] Preferably, the method by which the logic lockout monitoring module performs the current loop monitoring includes: When the standard operating procedure command instructs to remove the old meter current line, activate the active perturbation detection mode. Real-time monitoring of the real part of the complex impedance and the fingerprint stability index; If the real part of the complex impedance is greater than the preset safety short-circuit threshold, or if the real part of the complex impedance is less than or equal to the preset safety short-circuit threshold but the fingerprint stability index is greater than or equal to the preset fluctuation threshold, it is determined that the external short-circuit wire has a risk of being loose, not connected, or having unstable contact, and a command to prohibit disconnection is output. If the real part of the complex impedance is less than or equal to the preset safe short-circuit threshold, and the fingerprint stability index is less than the preset fluctuation threshold, the external short-circuit connection is determined to be reliable, and a disconnection command is output.

[0010] Preferred options also include: An environment-adaptive calibration module is used to acquire background noise signals during idle periods when no non-power frequency characteristic perturbation signals are injected. Analyze the spectral distribution of background noise signals to identify environmental interference frequencies; The transmission frequency of the non-power frequency characteristic perturbation signal is dynamically adjusted to avoid environmental interference frequencies and power frequency harmonic frequencies, and the operating parameters of the non-contact injection and acquisition module are updated.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention adopts non-contact active injection of non-power frequency micro-perturbation signal technology, which gets rid of the dependence of traditional solutions on power grid load energy; even under extreme conditions of no-load or small load on the power grid, the system can still act as an active source to accurately sense the connection status through the detection loop response, effectively solving the problem of monitoring instrument failure caused by insufficient load current, and ensuring the real-time performance and reliability of physical connection monitoring under all operating conditions. 2. This invention elevates the dimension of connection status identification from a single current amplitude to complex frequency domain impedance characteristics by constructing complex impedance spectra and topological impedance fingerprints. This technology can accurately distinguish between the resistive and inductive characteristics of a circuit, avoiding misjudgments of short circuit or open circuit states caused by random fluctuations in load current from the physical level, and significantly improving the accuracy of physical connection status judgment in complex circuit networks. 3. This invention introduces impedance fingerprint evolution path tracking and dynamic stability index, upgrading the traditional static continuity detection to dynamic contact characteristic analysis; the system can keenly capture micro impedance fluctuations caused by contact surface oxidation, loose screws, etc., effectively identify potential problems of loose connections or unstable contacts, prevent overheating or open circuit faults caused by poor contact, and fill the gap in the existing technology for dynamic contact quality monitoring. 4. This invention establishes a logic interlocking monitoring mechanism based on the operation timing state matrix, realizing real-time comparison between physical connection status and standard operating procedures; by forcibly executing safety logic such as neutral line before phase line and reliable short-circuiting before disconnection, an interlocking alarm is immediately output when a state mismatch or fault risk is detected, providing on-site operators with an automated safety barrier independent of human judgment. Attached Figure Description

[0012] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a structural diagram of the system of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0014] Example 1: Please see Figure 1 A smart sensor monitoring system for uninterrupted replacement of mutual inductance energy meters, comprising: The non-contact injection and acquisition module is configured to be snapped into the wiring circuit of the energy meter, inject non-power frequency characteristic perturbation signals into the circuit, and acquire the circuit response signal superimposed with the non-power frequency characteristic perturbation signals in real time. The impedance spectrum feature extraction module is configured to perform complex frequency domain transformation and deconstruction on the loop response signal, filter out power frequency fundamental wave interference, extract the frequency domain response features corresponding to non-power frequency characteristic perturbation signals, and generate complex impedance data. The topology fingerprint construction module is configured to construct a topology impedance fingerprint that characterizes the complex impedance characteristics of the current loop based on complex impedance data, and map the topology impedance fingerprint to a preset operation timing state matrix to determine the current physical connection state. The logic interlocking monitoring module is configured to acquire standard operating procedure instructions, compare the current physical connection status with the target status corresponding to the standard operating procedure instructions, and execute monitoring logic. The monitoring logic is configured as follows: if the current physical connection state matches the target state corresponding to the standard operation procedure instruction and meets the preset security unlocking conditions, then an unlocking signal is output. If the current physical connection status does not match the target status corresponding to the standard operating procedure instruction, does not meet the safety unlocking conditions, or the current physical connection status is determined to be a fault state, an interlocking alarm signal will be output.

[0015] This embodiment details the overall architecture and core functional logic of the system, aiming to solve the safety hazards caused by the inability to intuitively judge the physical connection status during the replacement of electricity meters without power interruption in the existing technology; the non-contact injection and acquisition module is configured as a clamp-shaped hardware device that can be clamped to the current input / output line or voltage terminal of the electricity meter. It does not rely on the original power frequency energy of the power grid, but acts as an active source to inject non-power frequency characteristic perturbation signals into the circuit under test. This signal is a low-voltage, high-frequency detection signal with a frequency significantly different from the fundamental frequency and major harmonics of the power grid. Its function is to act as a tracer particle to propagate in the circuit network, and its source is generated by the signal generator inside the system. The module simultaneously acquires the loop response signal superimposed on the perturbation signal in real time. The response signal contains information on the loop's reflection, attenuation, and phase shift of the perturbation signal. The impedance spectrum feature extraction module receives the circuit response signal, uses digital signal processing technology to perform complex frequency domain transformation on the signal, filters out high-energy power frequency fundamental wave interference, separates the weak non-power frequency characteristic signal, calculates its response characteristics in the frequency domain, and finally generates complex impedance data. The topology fingerprint construction module constructs a topology impedance fingerprint that characterizes the physical properties of the current loop based on complex impedance data, and maps the fingerprint to a preset operation timing state matrix; The operation timing state matrix is ​​a pre-stored data structure containing the set of ideal impedance parameters corresponding to each standard step in the entire process of replacing the electricity meter; The logic interlocking monitoring module acquires the current standard operating procedure instructions and compares the real-time measured current physical connection status with the target status required by the instructions. The specific execution method of the monitoring logic is as follows: In response to the current physical connection state matching the target state and meeting the preset security unlocking conditions, the system outputs an unlocking signal, allowing the operator to proceed with the next action; In response to a mismatch in status, failure to meet safety conditions, or a fault condition, the system immediately outputs a lockout alarm signal. This embodiment constructs a closed-loop monitoring system based on active non-power frequency perturbation signals. In the scenario of replacing electricity meters without power interruption, by upgrading the traditional passive monitoring based on current amplitude to active topology monitoring based on complex impedance spectrum, the system can still accurately determine the wiring status through the intrinsic impedance characteristics of the circuit even under extreme conditions where the power grid is unloaded or the load is extremely small, causing traditional multimeters to fail. This architecture effectively avoids the problem of misjudging short-circuit status caused by load current fluctuations from the physical level, providing operators with a safety barrier independent of the power grid operation status, and eliminating high-risk accidents such as open circuit on the secondary side of the CT or short circuit on the secondary side of the PT.

[0016] Example 2: The non-contact injection and acquisition module performs injection and acquisition using the following methods: Drive the high-frequency signal transmitting coil to generate a sine wave or pseudo-random sequence with a frequency in a preset high-frequency range as a non-power frequency characteristic perturbation signal; The principle of magnetic coupling is used to induce non-power frequency characteristic perturbation signals into the current or voltage circuit of the energy meter; A high-sensitivity pickup coil is used to detect composite electromagnetic waves in the circuit, convert the composite electromagnetic waves into analog voltage signals, and perform analog-to-digital conversion to obtain digital circuit response signals.

[0017] This embodiment further specifies the non-contact injection and acquisition module, and elaborates on the hardware collaboration steps in detail; The non-contact injection and acquisition module adopts an open-close clamp structure. The core material is preferably high-frequency ferrite or nanocrystalline alloy to ensure the permeability stability and magnetic circuit closure under high-frequency perturbation signals. The system drives a high-frequency signal transmitting coil, which is wound on a high-permeability magnetic core and driven by a power amplifier circuit to generate a sine wave or pseudo-random sequence with a frequency in a preset high-frequency range as the excitation source. This frequency band is selected to avoid interference from the power frequency and its low-order harmonics, while also avoiding the impact of distributed capacitance on the accuracy of impedance measurement caused by excessively high frequencies. Utilizing the principle of magnetic coupling, the transmitting coil serves as the primary side of the transformer, while the circuit wires of the measured energy meter serve as the secondary side. Through electromagnetic induction, non-power frequency characteristic perturbation signals are coupled and induced into the current or voltage circuit of the energy meter. This non-invasive injection method ensures electrical isolation between the sensor and the high-voltage circuit, guaranteeing the safety of equipment and personnel. A high-sensitivity pickup coil is used to detect composite electromagnetic waves in the circuit. The pickup coil is located downstream of the injection point or coaxially and is responsible for sensing the current change in the circuit. The coil converts the detected composite electromagnetic waves into an analog voltage signal. After passing through a conditioning circuit, the signal is sent to a high-precision analog-to-digital converter for analog-to-digital conversion, thereby obtaining a digital circuit response signal. This embodiment employs a combined strategy of magnetic coupling injection and high-sensitivity pickup technology to achieve complete electrical isolation from the high-voltage circuit under test in the complex electromagnetic environment of live-line operation. By utilizing a sine wave or pseudo-random sequence of a specific frequency as the detection signal, and in conjunction with the frequency response characteristics of the high-frequency transmitting and pickup coils, it is possible to clearly extract the detection signal at the microamp to milliamp level under background noise of power frequency load currents of up to tens of amperes. This design greatly improves the signal-to-noise ratio and the anti-interference capability of the measurement, ensuring the purity and safety of signal acquisition during uninterrupted power replacement operations.

[0018] Example 3: The methods for generating complex impedance data by the impedance spectrum feature extraction module include: Perform a Fast Fourier Transform on the loop response signal to obtain full-spectrum data; Locate the characteristic frequency points corresponding to non-power frequency characteristic perturbation signals in the full spectrum data; The amplitude and phase information at the characteristic frequency points are extracted, and the reflection coefficient of the circuit at the characteristic frequency is calculated. Based on the reflection coefficient and the preset sensor transfer function, the real part and imaginary part of the complex impedance of the circuit are calculated and combined to form complex impedance data.

[0019] This embodiment further specifies the impedance spectrum feature extraction module, and elaborates in detail the mathematical implementation process of how to extract complex impedance data from mixed signals; The time-domain loop response signal acquired by the ADC The formula for performing a Fast Fourier Transform is as follows: ; in, The total length of the sampling sequence. For time-domain sampling point index, For frequency domain spectral line indexing, The imaginary unit is used to convert the signal from the time domain to the frequency domain; In the full spectrum data, based on the frequency set by the transmitter. Locate its corresponding spectrum index ; The amplitude and phase data at this characteristic frequency point are extracted, and combined with the known injected signal reference source within the system, the complex voltage phasor at the characteristic frequency point is separated and obtained. With complex current phasor The specific mapping solution method is as follows: Assume the Thevenin equivalent output impedance of the non-contact injection module, pre-calibrated and converted to the loop side, is... Given that the ideal voltage phasor of the injection source is The current phasor obtained by the pickup coil and ADC acquisition and FFT transformation is denoted as... Based on the circuit equivalent model, the port voltage phasor at the characteristic frequency point The calculation formula is: ; At this time, the voltage phasor at this frequency With current phasor It was established for use in subsequent reflection coefficient calculations; The system calculates the reflection coefficient of the loop at the characteristic frequency based on the transmission line boundary condition model. The calculation formula is: ; in, For non-contact injection modules at characteristic frequencies The complex characteristic impedance is expressed as follows: This parameter is determined by snapping the device into the standard calibration loop at the factory and using the standard load on the loop side, including open circuit, short circuit, and... The standard resistor was measured using the three-point calibration method and stored in the system's non-volatile memory; Based on the reflection coefficient and a preset sensor transfer function Solve for the complex impedance of the circuit. The solution formula is: ; in, It is the pre-calibrated complex gain compensation coefficient of the sensor at the operating frequency; considering that the uncertainty of the closed air gap of the clamp core in field operation will affect the coupling efficiency, the system introduces a dynamic compensation mechanism: before injecting the perturbation signal, the non-contact injection and acquisition module first outputs a detection pulse to measure the real-time equivalent inductance of the transmitting coil. ; The detection pulse is configured as a low-voltage step signal with a preset rising edge, and its spectral energy is concentrated in a frequency band much higher than the power frequency, such as above 20kHz. After the system is configured with a high-pass digital filter at the acquisition end to filter out the power frequency component, the time constant is extracted from the transient response waveform of the step signal through the acquisition loop. ,based on The relational inversion calculation yields the real-time equivalent inductance under the current core closed state. ,in This is the total resistance value, including the DC resistance of the transmitting coil and the equivalent series resistance of the circuit. Read the standard inductance value stored in the memory when the magnetic core is fully closed. Calculate the coupling state coefficients: ; Based on the linear approximation assumption that the air gap in the magnetic core primarily affects the coupling amplitude, the dimensionless coupling state coefficient is used to correct the preset transfer function, resulting in the corrected transfer function. and will Substitute into the above formula and replace The system performs calculations to eliminate impedance measurement errors caused by incomplete jaw closure; the system then calculates the complex number... Decompose into real part With the imaginary part These are respectively used as the resistance component and the reactance component, which are combined to form complex impedance data; This embodiment utilizes FFT transform and complex frequency domain solution algorithms to construct a spectrum scalpel for mixed signals, accurately eliminating strong power frequency interference through the aforementioned analytical formula. This processing method enables the system to accurately distinguish the resistive and reactive characteristics of a circuit, providing a high-precision quantitative data foundation for subsequent identification of whether a short-circuit connection is loose and mainly affects resistance or whether an transformer is open and mainly affects reactance. Thus, refined fault diagnosis is achieved in complex circuit networks.

[0020] Example 4: The methods for constructing topological impedance fingerprints using the topological fingerprint construction module include: The real part of the complex impedance is taken as the resistive characteristic component, and the imaginary part of the complex impedance is taken as the inductive / capacitive characteristic component. Construct a two-dimensional impedance eigenvector and use the projection trajectory of the two-dimensional impedance eigenvector on the complex plane as a topological impedance fingerprint; The evolution path of the topological impedance fingerprint in the complex plane is tracked in real time, the rate of change of the evolution path is calculated, and the rate of change is used as the fingerprint stability index.

[0021] This embodiment further specifies the topological fingerprint construction module and clarifies the algorithmic definitions of fingerprints and stability indicators; The real part of the complex impedance obtained from the above calculation With the imaginary part of the complex impedance At any moment Constructed as a two-dimensional impedance eigenvector , where the superscript T indicates the vector transpose operation; The continuous projection trajectory of this vector onto the complex plane is defined as the topological impedance fingerprint; to quantify the reliability of the connection, the system calculates the instantaneous rate of change of the evolution path in real time, i.e., the fingerprint movement rate. The calculation formula is the difference of the Euclidean distance: ; This embodiment will use fingerprint stability indicators Defined as rate of change In the sliding time window The root mean square value within the range is calculated using the following formula: ; in The number of sampling points included in the sliding time window. For the summation variable, This is the current sampling time point; this indicator The physical meaning is the dynamic jitter energy of the impedance fingerprint per unit time; This embodiment upgrades traditional static impedance measurement to dynamic trajectory analysis by constructing a topological impedance fingerprint and introducing a well-defined dynamic stability index. In wiring operation scenarios, loose connections or poor contact often manifest as severe fluctuations in impedance values ​​on the complex plane, leading to... The value increases significantly; this embodiment can keenly capture this micro-vibration through the above algorithm, thereby effectively identifying potential risks of false connection or unstable contact, and preventing potential overheating failures caused by oxidation of the contact surface or loose screws.

[0022] Example 5: The methods used by the topology fingerprint building module to determine the current physical connection state include: Before the system is officially put into operation, an operation sequence state matrix is ​​pre-established: standard operation drills are conducted using the same type of energy meter, and the complex impedance data under each step is recorded. A sample set is constructed with the real and imaginary parts of the complex impedance as feature dimensions, and the standard fingerprint center for each state is generated using the K-Means clustering algorithm. and cluster radius The data is stored in the database. During the monitoring process, the preset operation timing state matrix is ​​accessed. The operation timing state matrix contains the standard fingerprint intervals corresponding to the normal operation state, short-circuit transition state and open circuit fault state. Calculate topological impedance fingerprint With respect to each standard state center point Euclidean distance , ; Select Euclidean distance The minimum value in is denoted as ,Right now ; and will The corresponding standard state is denoted as the candidate state. ;like Less than the preset cluster radius threshold Then the candidate state Determine the current physical connection state; if If so, it is determined to be an unknown state; When the standard operating procedure instruction is to short-circuit the secondary side of the current transformer, the current physical connection state is confirmed to be a reliable short-circuit state only when the topological impedance fingerprint falls into the low impedance closed interval corresponding to the short-circuit transition state and the real part of the complex impedance is less than the preset safe short-circuit threshold.

[0023] This embodiment is a further specification of how the topology fingerprint construction module determines the current physical connection state; The system access operation timing state matrix pre-stores the standard fingerprint range of each state, including normal operation state, short-circuit transition state and open circuit fault state. Calculate the Euclidean distance between the real-time acquired topological impedance fingerprint and the center point of each standard fingerprint interval; The state corresponding to the standard fingerprint interval with the smallest Euclidean distance is determined as the current physical connection state. On this basis, when the standard operation procedure instruction is a short-circuit operation on the secondary side of the current transformer, the system executes a stricter judgment logic: only when the topological impedance fingerprint falls into the low impedance closed interval corresponding to the short-circuit transition state, and at the same time satisfies that the real part of the complex impedance is less than the preset safe short-circuit threshold, is the current physical connection state confirmed as a reliable short-circuit state. Among them, the preset safety short-circuit threshold The value is set according to the contact resistance specification of the secondary circuit of the current transformer, and the preferred range is [range missing]. to This threshold must be much smaller than the rated load impedance on the secondary side of the current transformer, typically 1. to This is to ensure the effectiveness of short-circuit splitting; that is... ,in The statistical standard deviation of the real part of the complex impedance data of the pre-collected shorting piece under reliable connection state is based on the statistical law of normal distribution. This threshold covers about 99.73% of the normal fluctuation samples in the data distribution and can effectively remove outlier noise caused by transient electromagnetic interference. This embodiment utilizes the concept of cluster analysis to transform complex circuit state identification into distance calculation in geometric space, thereby achieving automated classification and identification of states. In particular, for the high-risk operation of CT short-circuiting, a hard constraint of the real part threshold of complex impedance is added to ensure that the operation is only considered successful when the physical connection resistance is small enough to effectively shunt the secondary current of the CT. This dual determination mechanism avoids misjudgment caused by inductive interference and ensures the electrical effectiveness of the short-circuiting operation.

[0024] Example 6: The logic interlock monitoring module performs voltage loop monitoring using the following methods: When the standard operating procedure instruction indicates to perform voltage loop wiring, obtain the ground impedance magnitude value corresponding to the topological impedance fingerprint; If the ground impedance modulus is greater than the preset neutral line connection threshold, it is identified as a neutral line disconnection state, and a blocking alarm signal for phase line connection is output. If the impedance modulus to ground is less than or equal to the preset neutral line connection threshold, it is identified as a neutral line connection state, and an unlocking signal is output for the phase line connection, forcibly executing the connection sequence of neutral line first and then phase line.

[0025] This embodiment further specifies the voltage loop monitoring performed by the logic interlock monitoring module; when the standard operating procedure instruction indicates that voltage loop wiring should be performed, the system pays attention to the connection status of the neutral line; Based on the currently constructed topological impedance fingerprint, the system resolves the equivalent ground impedance magnitude of the loop, which is the total impedance magnitude of the loop including the neutral grounding loop obtained by non-contact injection signal sensing. Since the neutral line is usually grounded, this impedance magnitude can reflect the degree of loop closure to ground through the neutral line. Execute threshold comparison logic: In response to the ground impedance modulus being greater than the preset neutral line connection threshold, it indicates that the circuit is in a high resistance state to ground, that is, the circuit is not effectively closed through the neutral line, and is identified as a neutral line unconnected state. At this time, the system outputs a lockout alarm signal for phase line connection, prohibiting the operator from connecting the live wire first. When the impedance modulus to ground is less than or equal to the preset neutral line connection threshold, it indicates that the loop has been effectively grounded through the N line to form a low-resistance path, and the system is identified as having a neutral line connection. At this time, the system outputs an unlocking signal for the phase line connection. In this embodiment, in the wiring scenario of a three-phase four-wire energy meter, the physical characteristic that the N line is usually grounded is used to enforce the wiring sequence of neutral line first and phase line second. This logic interlocking mechanism fundamentally eliminates the risk of neutral point drift caused by incorrect operation sequence, prevents accidents such as burning out the energy meter or load due to the instantaneous rise of some phase voltage to line voltage, and ensures the safety of valuable metering equipment and user load.

[0026] Example 7: The methods by which the logic-locked monitoring module performs current loop monitoring include: When the standard operating procedure command instructs to remove the old meter current line, the active perturbation detection mode is activated; the real part of the complex impedance and fingerprint stability index are monitored in real time. If the real part of the complex impedance is greater than the preset safety short-circuit threshold, or if the real part of the complex impedance is less than or equal to the preset safety short-circuit threshold but the fingerprint stability index is greater than or equal to the preset fluctuation threshold, it is determined that there is a risk of loose connection, no connection or unstable contact in the external short-circuit wire, and a command to prohibit disconnection is output. If the real part of the complex impedance is less than or equal to the preset safe short-circuit threshold, and the fingerprint stability index is less than the preset fluctuation threshold, the external short-circuit connection is determined to be reliable, and a disconnection command is output.

[0027] This embodiment further specifies the current loop monitoring performed by the logic lockout monitoring module, focusing on the safety verification of CT secondary side short circuit; when the standard operating procedure instruction indicates the removal of the old meter current line, the system activates the active perturbation detection mode and automatically increases the sampling rate of the injected signal; The system monitors the real part of the complex impedance and the aforementioned fingerprint stability index in real time; it executes risk judgment logic: if the real part of the complex impedance is greater than the preset safe short-circuit threshold, it indicates that the resistance of the short-circuit circuit is too large and the current shunting capacity is insufficient; or, if the real part of the complex impedance meets the standard but the fingerprint stability index is greater than or equal to the preset fluctuation threshold, it indicates that the shorting wire has instability caused by jitter, poor connection or oxidation of the contact surface; in any of the above situations, the system determines that the external shorting wire has a risk of poor connection, no connection or unstable contact, and immediately outputs a command to prohibit disconnection. Only when the real part of the complex impedance is less than or equal to the preset safe short-circuit threshold and the fingerprint stability index is less than the preset fluctuation threshold, it indicates that the short-circuit connection is both low-impedance and stable. The system determines that the external short-circuit connection is reliable and outputs a command to allow disconnection. This embodiment innovatively introduces a dual verification mechanism of low impedance and high stability for the high-risk step of removing the shorting wire on the CT secondary side. Existing technologies often only focus on the static resistance of continuity, while ignoring the dynamic contact characteristics of stability. This solution can identify hidden high-risk conditions such as hands pressing on the shorting wire but not tightening it, preventing operators from rashly removing the old meter when the shorting wire is not completely and reliably fixed, thereby avoiding the high-voltage arc caused by the instantaneous open circuit on the CT secondary side, which could cause injury to personnel.

[0028] Example 8: The system also includes: An environment-adaptive calibration module is used to acquire background noise signals during idle periods when no non-power frequency characteristic perturbation signals are injected. Analyze the spectral distribution of background noise signals to identify environmental interference frequencies; the specific frequency optimization logic is as follows: set the system's operating frequency band range. and search step size In the background noise spectrum, with bandwidth Preferably, the frequency range is 500Hz to 1kHz, which is used for calculating the noise energy spectral density integral at each frequency point using a sliding window. The calculation formula is: ; Here For frequency integral variables, This represents the noise spectrum amplitude density, i.e., the voltage amplitude spectrum after the background noise has undergone FFT transformation. Traversing the entire frequency band, the search enables minimum frequency point ;judge Whether it falls within the protection band of the power frequency and its odd harmonics; if it does not fall within the protection band, then... Lock onto the target transmission frequency of the non-power frequency characteristic perturbation signal; if it falls within the guard band, then... The system continues to search for the next smallest frequency point until a clean frequency point that meets the requirements is found. The system dynamically adjusts the transmission frequency of the non-power frequency characteristic perturbation signal to avoid environmental interference frequencies and power frequency harmonic frequencies, and updates the working parameters of the non-contact injection and acquisition module.

[0029] This embodiment supplements the system's environmental adaptive capability and involves an environmental adaptive calibration module; During idle periods when no non-power frequency characteristic perturbation signals are injected, the environmental adaptive calibration module controls the non-contact acquisition module to operate in pure receiving mode and acquire the current loop electromagnetic environment noise. Spectral analysis of the collected noise is performed to identify environmental interference frequencies, such as specific subharmonics in the power grid or high-frequency carrier interference generated by nearby frequency converters. The system automatically and dynamically adjusts the transmission frequency of non-power frequency characteristic perturbation signals to avoid the environmental interference frequencies and power frequency harmonic frequencies identified above, and updates the operating parameters of the non-contact injection and acquisition module to ensure a high signal-to-noise ratio in subsequent measurements. This embodiment achieves adaptive frequency hopping of the detection frequency through a spectrum sensing mechanism of listening before transmitting, effectively solving the problem of fixed frequency detection failure caused by the complex and ever-changing electromagnetic environment on site. In industrial sites with a large number of nonlinear loads or high-frequency interference sources, this mechanism ensures that the system can still avoid interference frequency bands and maintain extremely high measurement accuracy and reliability, verifying the robustness of this technical solution under complex working conditions.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system, characterized in that, The application relates to a non-contact injection and collection module configured to be connected to a power meter wiring loop, inject a non-power frequency characteristic perturbation signal into the loop, and collect a loop response signal superimposed with the non-power frequency characteristic perturbation signal in real time. An impedance spectrum feature extraction module is configured to perform complex frequency domain transformation and deconstruction on the loop response signal, filter out power frequency fundamental wave interference, extract frequency domain response features corresponding to the non-power frequency characteristic perturbation signal, and generate complex impedance data. A topology fingerprint construction module is configured to construct a topology impedance fingerprint representing current loop complex impedance characteristics based on the complex impedance data, map the topology impedance fingerprint to a preset operation timing state matrix, and determine a current physical connection state. A logic lock monitoring module is configured to obtain standard operation process instructions, compare the current physical connection state with a target state corresponding to the standard operation process instructions, and execute monitoring logic. The monitoring logic is configured to output an unlock signal if the current physical connection state matches the target state corresponding to the standard operation process instructions and meets a preset safety unlocking condition, and output a lock alarm signal if the current physical connection state does not match the target state corresponding to the standard operation process instructions, does not meet the safety unlocking condition, or is determined to be a fault state. The method for the non-contact injection and collection module to perform injection and collection comprises the following steps.

2. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 1, characterized in that, A high-frequency signal transmitting coil is driven to generate a sine wave or a pseudo-random sequence with a frequency in a preset high-frequency interval as a non-power frequency characteristic perturbation signal. The non-power frequency characteristic perturbation signal is inducted into a current loop or a voltage loop of the power meter by using a magnetic coupling principle. A high-sensitivity pickup coil is used to detect the composite electromagnetic wave in the loop, convert the composite electromagnetic wave into an analog voltage signal, and perform analog-digital conversion to obtain a digitized loop response signal. The method for the impedance spectrum feature extraction module to generate complex impedance data comprises the following steps.

3. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 2, characterized in that, Fast Fourier transform is performed on the loop response signal to obtain full spectrum data. A characteristic frequency point corresponding to the non-power frequency characteristic perturbation signal is located in the full spectrum data. Amplitude information and phase information at the characteristic frequency point are extracted, and a reflection coefficient of the loop at the characteristic frequency is calculated. Based on the reflection coefficient and a preset sensor transfer function, the real part and the imaginary part of the complex impedance of the loop are calculated to form the complex impedance data. The method for the topology fingerprint construction module to construct a topology impedance fingerprint comprises the following steps.

4. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 3, characterized in that, The real part of the complex impedance is taken as a resistive characteristic component, and the imaginary part of the complex impedance is taken as an inductive / capacitive characteristic component. A two-dimensional impedance characteristic vector is constructed, and a projection trajectory of the two-dimensional impedance characteristic vector on a complex plane is taken as the topology impedance fingerprint. An evolution path of the topology impedance fingerprint on the complex plane is tracked in real time, a change rate of the evolution path is calculated, and the change rate is taken as a fingerprint stability index. The method for the topology fingerprint construction module to determine a current physical connection state comprises the following steps.

5. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 4, characterized in that, A preset operation timing state matrix is accessed, and the operation timing state matrix contains standard fingerprint intervals corresponding to a normal operation state, a short-circuit transition state and an open-circuit fault state. The Euclidean distance between the topology impedance fingerprint and each standard fingerprint interval is calculated. ​ The state corresponding to the standard fingerprint interval with the minimum Euclidean distance is determined as the current physical connection state; When the standard operation flow instruction is a current transformer secondary side short-circuit operation, only when the topology impedance fingerprint falls into a low-impedance closed interval corresponding to a short-circuit transition state, and the real part of the complex impedance is less than a preset safe short-circuit threshold, it is determined that the current physical connection state is a short-circuit reliable state.

6. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 5, characterized in that, The method for the logic lockout monitoring module to perform the voltage loop monitoring includes: When the standard operation flow instruction indicates a voltage loop wiring, the modulus of the topology impedance fingerprint corresponding to the ground impedance is obtained; If the modulus of the ground impedance is greater than a preset neutral line connection threshold, it is identified as a neutral line unconnected state, and a lockout alarm signal for phase line wiring is outputted; If the modulus of the ground impedance is less than or equal to the preset neutral line connection threshold, it is identified as a neutral line connected state, and an unlock signal for phase line wiring is outputted, and the wiring sequence of neutral line first and phase line second is forcedly executed.

7. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 5, characterized in that, The method for the logic lockout monitoring module to perform the current loop monitoring includes: When the standard operation flow instruction indicates the removal of an old meter current line, an active disturbance detection mode is activated; The real part of the complex impedance and the fingerprint stability index are monitored in real time; If the real part of the complex impedance is greater than a preset safe short-circuit threshold, or the real part of the complex impedance is less than or equal to the preset safe short-circuit threshold but the fingerprint stability index is greater than or equal to a preset fluctuation threshold, it is determined that there is a risk of virtual connection, non-connection or unstable connection of an external short-circuit line, and a disconnection prohibition instruction is outputted; If the real part of the complex impedance is less than or equal to the preset safe short-circuit threshold, and the fingerprint stability index is less than the preset fluctuation threshold, it is determined that the external short-circuit line is reliably connected, and a disconnection permission instruction is outputted.

8. The mutual inductance type electric energy meter non-stop power replacement intelligent sensor monitoring system according to claim 1, characterized in that, Further comprising: An environment adaptive calibration module is configured to collect background noise signals in an idle period without injecting non-power frequency characteristic disturbance signals; Analyze the frequency spectrum distribution of the background noise signals to identify environmental interference frequencies; Dynamically adjust the emission frequency of the non-power frequency characteristic disturbance signals to avoid environmental interference frequencies and power frequency harmonic frequencies, and update the working parameters of the non-contact injection and collection module.

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