A novel power distribution system operation state active sensing method, system and device

Abstract

This invention discloses a novel method and system for actively sensing the operating status of a power distribution system. The method includes: identifying multiple monitoring points in the power distribution system; actively injecting a power frequency signal into the neutral point and simultaneously acquiring the three-phase and zero-sequence electrical quantities at each monitoring point; then decomposing the quantities into positive-sequence, negative-sequence, and composite zero-sequence components using the symmetrical component method; and comparing the composite zero-sequence quantity with the measured zero-sequence quantity to accurately determine whether the monitoring terminal is functioning correctly, thereby identifying reliable diagnostic sections and avoiding misjudgments caused by measurement anomalies. Based on this, the load imbalance is quantified by the ratio of negative-sequence to positive-sequence current at normal monitoring points, providing a direct assessment of the economic efficiency of the power grid operation. Simultaneously, the zero-sequence impedance is calculated using the zero-sequence voltage and current under normal conditions to effectively verify the protection settings of the switching equipment. Finally, a state evaluation equation integrating multiple characteristic quantities is established to output the normal or fault state of the power grid in real time. This method can actively sense the operating status of the power distribution system during normal operation.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a novel method, system and device for actively sensing the operating status of a power distribution system. Background Technology

[0002] With the large-scale integration of distributed renewable energy and new loads into power distribution systems, the scale of these systems is constantly expanding and their network structures are becoming increasingly complex. This places higher demands on the accuracy and real-time performance of power distribution system operational status sensing. Currently, power distribution system status sensing mainly relies on electrical quantity data provided by monitoring terminals (such as feeder terminal units, FTUs) and fault indicators installed on the lines. However, existing sensing methods have the following problems: they ignore situations that may occur during long-term operation of the monitoring terminals, such as transformer disconnection, wiring errors, sampling circuit drift, or device malfunctions, and they lack proactive sensing technology. This results in the inability to obtain advance, accurate, and in-depth sensing of the operational status of new power distribution systems, seriously affecting the further improvement of power supply reliability and renewable energy absorption rate.

[0003] Furthermore, this passive response mode is difficult to meet the needs of intelligent operation and maintenance of new power distribution systems, and cannot realize the calculation and prediction of operating status and fault early warning. Summary of the Invention

[0004] Based on this, it is necessary to propose a new method and system for actively sensing the operating status of power distribution systems to address the above problems.

[0005] This application proposes a novel method for actively sensing the operating status of a power distribution system, the method comprising: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and composite zero sequence voltage and composite zero sequence current are calculated using the symmetrical component method for the measurement of three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0006] In the above scheme, the step of evaluating whether the state of the monitoring terminal measurement circuit is normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current specifically includes: When the zero-sequence voltage is measured Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ; When the zero-sequence voltage is measured Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ; When the zero-sequence current is measured Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ; When the zero-sequence current is measured Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ; in, To measure zero-sequence voltage; To synthesize the zero-sequence voltage; To measure zero-sequence current; To calculate the zero-sequence current; Mod() is the modulus function; arg() is the phase angle function; P u P is the voltage amplitude deviation threshold; i The current amplitude deviation threshold; A u Voltage phase angle deviation threshold; A i This is the current phase angle deviation threshold. When both the current measurement circuit and the voltage measurement circuit at the monitoring point are in normal condition, the measurement circuit status of the monitoring terminal is determined to be normal; otherwise, the measurement circuit status of the monitoring terminal is determined to be abnormal.

[0007] In the above scheme, the economic efficiency of determining the power grid operating status downstream of each monitoring terminal by using the ratio of negative-sequence current to positive-sequence current at the normal operating monitoring point includes: S31. Calculate the power grid operation economic coefficient at each monitoring terminal of each line, including:

[0008] in, Let K be the power grid operation economic coefficient at the monitoring terminal of the k-th line. For the negative sequence current component of the monitoring terminal of the k-th line; Let be the positive sequence current component of the monitoring terminal of the k-th line; S32. If the power grid operation economic coefficient at the line monitoring terminal is not greater than the first threshold of power grid operation economic, the power grid operation economic status at the line monitoring terminal is judged to be normal. If the power grid operation economy coefficient at the line monitoring terminal is between the first threshold and the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in an economic attention state. If the power grid operation economy coefficient at the line monitoring terminal is greater than the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in a low economic state. The first threshold for the economic efficiency of power grid operation ranges from 1% to 5%; the second threshold for the economic efficiency of power grid operation ranges from 3% to 15%; and the third threshold for the economic efficiency of power grid operation ranges from 15% to 100%.

[0009] In the above scheme, the step of calculating the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current of the normal state monitoring point, and determining the protection setting state of the switchgear based on the zero-sequence impedance, includes: S41. Determine the zero-sequence impedance during normal operation based on the amplitude of the zero-sequence voltage and zero-sequence current at the normal state monitoring point; S42. The reference zero-sequence protection setting value of the monitoring terminal is calculated according to the following formula:

[0010] in, This is the accurate zero-sequence protection setting when the monitoring terminal of the k-th line fails; m is the reliability coefficient, typically taken as 1.1~4; The rated voltage of the power distribution system; The measured or synthesized zero-sequence current amplitude of the monitoring terminal of the k-th line; The measured or synthesized zero-sequence voltage amplitude of the monitoring terminal of the k-th line; S43. If the deviation between the protection setting value of the switchgear and the reference zero-sequence protection setting value exceeds 30%, the protection setting value of the switchgear is determined to be in an abnormal state; otherwise, it is in a normal state.

[0011] In the above scheme, before establishing the power grid state evaluation equation, the phase impedance of each monitoring point is obtained, including: S51. During normal operation, different power frequency signals are actively injected into the neutral point three times to obtain the measured three-phase voltage and three-phase current at each monitoring point; S52. Solve the following equations to obtain the phase impedance at each monitoring point;

[0012] in, , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is first injected into the neutral point for the first time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is first injected into the neutral point for the first time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the second time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is injected into the neutral point for the second time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the third time; , , The three-phase current vector of the k-th monitoring terminal is obtained when the power frequency signal is injected into the neutral point for the third time. , , These are the phase impedances at the kth monitoring terminal, respectively.

[0013] In the above scheme, the step of establishing a power grid state evaluation equation, calculating the power grid state in real time, and determining whether the power grid state is normal or faulty includes: S61. The power grid state evaluation equations for each monitoring point are established as follows:

[0014] in, , , These are the three-phase voltage vectors of the k-th monitoring terminal obtained in real time; , , These are the three-phase current vectors of the k-th monitoring terminal obtained in real time; The zero-sequence voltage vector of the k-th monitoring terminal is obtained in real time; The zero-sequence current vector of the k-th monitoring terminal is obtained in real time; , , These are the phase impedances at the kth monitoring terminal, respectively; Let be the parallel impedance of the three-phase impedance of the k-th monitoring terminal; S62. Calculate the first obtained vector A according to the following formulas. k Second obtain vector B k for:

[0015] S63. If the first obtained vector A k Second obtain vector B k The amplitudes of all vectors are not greater than the amplitude threshold, and the first obtained vector A k Second obtain vector B k If the absolute value of the phase angle is not greater than the phase angle threshold, it is determined that the power grid after the kth monitoring terminal is in a normal state; otherwise, it is in a fault state. The amplitude threshold is 5mA; the phase angle threshold is 30°.

[0016] In the above scheme, the zero-sequence voltage and zero-sequence current are obtained according to the following steps: Injecting power frequency voltage and current into the neutral point of the power distribution system; Adjust the amplitude of the power frequency voltage and power frequency current so that the neutral point displacement voltage in the power distribution system exceeds the zero-sequence voltage start-up setting value of each monitoring terminal; When the monitoring terminal detects that the zero-sequence voltage exceeds the start-up setting value, the measured zero-sequence voltage and measured zero-sequence current at the injection moment will be used as the measured zero-sequence voltage and measured zero-sequence current.

[0017] This application also proposes a novel active sensing system for the operating status of a power distribution system, comprising: Several monitoring terminals are installed on the power distribution line, arranged in order from the power supply side to the load side, to collect the zero-sequence voltage and zero-sequence current at their respective locations; The neutral point active injection device is installed at the neutral point of the power distribution system and is used to actively inject power frequency voltage signals and power frequency current signals into the neutral point of the power distribution system under normal operating conditions. The main data processing platform is communicatively connected to the multiple monitoring terminals and the neutral point active injection device, and includes: The data acquisition module is used to acquire the measured zero-sequence voltage and measured zero-sequence current uploaded by each monitoring terminal, as well as the synthesized zero-sequence voltage and calculated zero-sequence current corresponding to each monitoring terminal. The measurement loop status judgment module is used to determine whether the measurement loop status of each monitoring point is normal based on the amplitude deviation and phase angle deviation between the synthesized zero-sequence voltage and the calculated zero-sequence current and the measured zero-sequence voltage and the measured zero-sequence current. The economic evaluation module for operating status is used to determine the economic efficiency of the power grid operating status behind each monitoring terminal by using the ratio of negative sequence current to positive sequence current of the normal state monitoring terminal. The protection setting status judgment module is used to calculate the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current of the normal state monitoring point, obtain an accurate zero-sequence impedance value, and judge the protection setting status of the switchgear. The power grid status evaluation module is used to obtain the impedance of each phase of the power grid, establish the power grid status evaluation equation, calculate the power grid status in real time, and determine whether the power grid status is normal or faulty.

[0018] This application also proposes a readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the following steps: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and composite zero sequence voltage and composite zero sequence current are calculated using the symmetrical component method for the measurement of three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0019] This application also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor in the following steps: Perform the following steps: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and composite zero sequence voltage and composite zero sequence current are calculated using the symmetrical component method for the measurement of three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0020] The present invention has the following beneficial effects: By actively injecting power frequency signals into the neutral point and simultaneously acquiring the three-phase and zero-sequence electrical quantities of each monitoring point, and then using the symmetrical component method to decompose the positive-sequence, negative-sequence, and synthetic zero-sequence components, the present invention can decouple the monitoring terminal's own circuit state from the power grid's operating state for evaluation. First, the synthetic zero-sequence is compared with the measured zero-sequence to determine whether the monitoring terminal is normal, thereby screening out reliable diagnostic sections and avoiding misjudgments due to measurement anomalies. On this basis, the ratio of negative-sequence current to positive-sequence current at normal monitoring points directly reflects the load imbalance and economy. The measured zero-sequence impedance is used to determine whether the protection setting is reasonable. Finally, a state evaluation equation integrating multiple characteristic quantities is established, realizing a closed-loop reasoning from terminal self-testing—section division—economic judgment—protection setting verification—global state identification. It can actively perceive the operating state of the power distribution system during normal operation, significantly improving the accuracy of state evaluation and self-diagnosis capabilities. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] in,: Figure 1 This is a schematic flowchart of a novel active sensing method for the operating status of a power distribution system in one embodiment. Figure 2 This is a schematic diagram of a structure in one embodiment where multiple monitoring points are deployed on a power distribution line; Figure 3 This is a schematic diagram of a novel active sensing system for the operating status of a power distribution system in one embodiment. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention; however, it will be apparent to those skilled in the art that the invention may be practiced without one or more of these details; in other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the invention. It should be understood that the invention can be practiced in different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms, unless the context clearly indicates otherwise. The terms “comprising” and / or “including,” when used in this specification, identify the presence of said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0026] To fully understand the present invention, a detailed structure will be presented in the following description in order to illustrate the technical solution proposed by the present invention; optional embodiments of the present invention are described in detail below, however, in addition to these detailed descriptions, the present invention may have other embodiments.

[0027] like Figure 1 As shown, in one embodiment, a novel method and system for actively sensing the operating status of a power distribution system are provided. The novel method for actively sensing the operating status of a power distribution system includes steps S101 to S106, which are detailed below: S101. Determine multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. This method establishes a complete and synchronous data acquisition foundation for subsequent active signal injection and state perception by identifying multiple monitoring points in the power distribution system capable of simultaneously monitoring three-phase voltage, three-phase current, and zero-sequence voltage and current. The multi-point deployment not only supports the calculation of positive-sequence, negative-sequence, and synthetic zero-sequence components using the symmetrical component method, effectively distinguishing between normal operation and fault precursors, but also enables self-testing of monitoring terminals and diagnostic section division through comparison of measured and synthetic zero-sequence values. Simultaneously, the parallel acquisition of three-phase and zero-sequence quantities significantly improves the accuracy of unbalance assessment, zero-sequence impedance calculation, and protection setting verification. This allows for closed-loop perception from terminal state self-testing and economic judgment to overall power grid state identification during normal operation, greatly enhancing the accuracy, reliability, and fault early warning capabilities of the power distribution system's state assessment.

[0028] like Figure 2 As shown, by deploying multiple monitoring points along the power distribution line from the power source side to the load side, the power distribution line, which was originally monitored as a whole, is physically divided into multiple independently monitorable units. This segmented monitoring architecture is the foundation for subsequent precise location of fault sections.

[0029] By arranging the monitoring points in order from the power source to the load side, a clear upstream and downstream topological relationship is assigned. This orderliness allows the system to understand the power supply direction of the distribution system, providing a topological basis for subsequent logical judgments based on electrical quantity characteristics, such as determining the direction of fault current and identifying which segment the fault is located in. Compared to setting up a single monitoring point only at the substation outlet, the multi-point deployment scheme allows the monitoring system to be flexibly expanded to branch lines and end loads, resulting in wider coverage and finer monitoring granularity.

[0030] Preferably, dual monitoring points are set up in critical sections (such as branch lines connecting important users, and connection points between cables and overhead lines). This involves two independent terminals on the same tower, each receiving data from different CT and voltage sensors. Under normal conditions, the data from the two terminals are used to verify each other. If the measured zero sequence of one terminal does not match the synthesized zero sequence, that terminal is marked as abnormal, but the other terminal still ensures the diagnostic capability of that section. This arrangement effectively avoids the situation where a single-point measurement loop failure leads to an unknown status of the entire section, improving the availability of the sensing system.

[0031] S102. During normal operation, actively inject power frequency signals into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point. In some embodiments, the zero-sequence voltage and zero-sequence current are obtained according to the following steps: Injecting power frequency voltage and current into the neutral point of the power distribution system; Adjust the amplitude of power frequency voltage and power frequency current so that the neutral point displacement voltage in the power distribution system exceeds the zero-sequence voltage start-up setting value of each monitoring terminal; When the monitoring terminal detects that the zero-sequence voltage exceeds the start-up setting value, the measured zero-sequence voltage and measured zero-sequence current at the injection moment will be used as the measured zero-sequence voltage and measured zero-sequence current.

[0032] By actively injecting adjustable amplitude power frequency voltage and current into the neutral point of the distribution system, and ensuring that the neutral point displacement voltage exceeds the zero-sequence voltage start-up setting value of each monitoring terminal, all monitoring terminals are forced to synchronously record and measure the zero-sequence voltage and zero-sequence current at the same injection time. This transforms the passive waiting for the occurrence of fault zero-sequence components into the active creation of a controllable zero-sequence excitation source, enabling the power grid to obtain synchronous, sufficiently large, and high signal-to-noise ratio zero-sequence electrical quantities across the entire network during normal operation. This effectively overcomes the problem of weak or missing zero-sequence signals during normal operation, providing reliable and repeatable active test data for subsequent monitoring terminal circuit status self-checking, accurate calculation of zero-sequence impedance, and protection setting verification based on the comparison of synthetic and measured zero-sequence, significantly improving the initiative of status perception and the reliability of diagnosis.

[0033] S103. The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and composite zero sequence voltage and composite zero sequence current are calculated using the symmetrical component method for measuring three-phase voltage and three-phase current. By applying the symmetrical component method to the measured three-phase voltage and three-phase current, the actual collected asymmetrical electrical quantities can be decomposed into positive-sequence, negative-sequence, and composite zero-sequence components. The positive-sequence component reflects the normal energy transmission state and provides a benchmark for economic evaluation. This step provides a characteristic parameter with strong anti-interference capability for subsequent diagnostic section division, economic judgment, and protection setting verification.

[0034] S104. Evaluate the status of the monitoring terminal's measurement circuit as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current, and divide the diagnostic sections according to the normal state of the monitoring terminal. By comparing the calculated composite zero-sequence voltage and current with the directly measured zero-sequence voltage and current, the status of each monitoring terminal's measurement circuit can be effectively assessed. Under the excitation of an actively injected signal, if the composite zero-sequence voltage and the measured zero-sequence voltage and current of a certain monitoring terminal are consistent in amplitude and phase, the terminal is determined to be in a normal state; otherwise, it is in an abnormal state, thus realizing the online self-testing and fault identification of the monitoring terminal itself. Based on this, only the monitoring terminals in a normal state are selected, and the distribution network is divided into several reliable diagnostic sections based on their locations.

[0035] This avoids misjudging the status of the entire power grid section due to abnormalities in individual terminal measurement circuits (such as CT disconnection or PT drift), ensuring that the data sources used for subsequent economic judgments, protection setting verification, and status evaluation are authentic and reliable, and significantly improving the fault tolerance and diagnostic accuracy of global perception.

[0036] Furthermore, before fault diagnosis, the data source is cleaned and monitoring points with normal measurement loop status are selected as the basis for subsequent analysis. This fundamentally eliminates the risk of misjudgment or failure of the entire positioning system due to the failure of a single monitoring point, and significantly improves the accuracy and reliability of fault location results.

[0037] In some embodiments, the status of the monitoring terminal measurement circuit is evaluated as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Specifically, this includes: When measuring zero-sequence voltage Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ; When measuring zero-sequence voltage Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ; When measuring zero-sequence current Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ; When measuring zero-sequence current Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ; in, To measure zero-sequence voltage; To synthesize the zero-sequence voltage; To measure zero-sequence current; To calculate the zero-sequence current; Mod() is the modulus function; arg() is the phase angle function; Pu is the voltage amplitude deviation threshold; Pi is the current amplitude deviation threshold; Au is the voltage phase angle deviation threshold; Ai is the current phase angle deviation threshold; When both the current measurement circuit and the voltage measurement circuit at the monitoring point are in normal condition, the measurement circuit status of the monitoring terminal is determined to be normal; otherwise, the measurement circuit status of the monitoring terminal is determined to be abnormal.

[0038] This embodiment transforms the comparison between the synthesized zero sequence and the measured zero sequence from a qualitative judgment to a quantitative one by introducing specific amplitude deviation thresholds and phase angle deviation thresholds. This significantly improves the rigor and operability of the monitoring terminal's measurement circuit status assessment. It independently verifies the voltage and current circuits, accurately pinpointing whether the anomaly is in voltage or current measurement, rather than simply labeling the terminal as faulty. By setting reasonable deviation thresholds, it effectively filters out normal measurement errors and minor disturbances, avoiding misjudgments. Furthermore, it quickly identifies anomalies such as transformer drift, wiring errors, or sampling circuit faults once the deviation exceeds the limit. Only when both the voltage and current circuits are in a normal state is the monitoring terminal considered to be in overall normal condition, ensuring the complete reliability of the data source upon which subsequent diagnostic segmentation relies.

[0039] S105. Use the ratio of negative sequence current to positive sequence current at the monitoring point under normal operation to determine the economic efficiency of the power grid operation status behind each monitoring terminal. In some embodiments, the economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative-sequence current to positive-sequence current at monitoring points in normal operation, including: S31. Calculate the power grid operation economic coefficient at each monitoring terminal of each line, including:

[0040] in, Let K be the power grid operation economic coefficient at the monitoring terminal of the k-th line. For the negative sequence current component of the monitoring terminal of the k-th line; Let be the positive sequence current component of the monitoring terminal of the k-th line; S32. If the power grid operation economic coefficient at the line monitoring terminal is not greater than the first threshold of power grid operation economic, the power grid operation economic status at the line monitoring terminal is judged to be normal. If the power grid operation economy coefficient at the line monitoring terminal is between the first threshold and the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in an economic attention state. If the power grid operation economy coefficient at the line monitoring terminal is greater than the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in a low economic state. Among them, the first threshold for the economic efficiency of power grid operation ranges from 1% to 5%; the second threshold for the economic efficiency of power grid operation ranges from 3% to 15%; and the third threshold for the economic efficiency of power grid operation ranges from 15% to 100%.

[0041] By calculating the ratio of negative-sequence current to positive-sequence current at monitoring points under normal operating conditions and setting tiered thresholds, the economic efficiency of power grid operation is quantified into three levels: normal, warning, and low. The negative-sequence current directly reflects the additional losses and reverse-field braking effect caused by three-phase unbalanced loads. The smaller the ratio, the closer the system is to symmetrical operation, and the better the power quality and economy. Compared to traditional methods that rely solely on power factor or total current, this indicator has a clear physical meaning, is simple to calculate, and only requires existing monitoring data without additional investment. The ratio obtained through normal-state monitoring terminals can accurately pinpoint specific sections of economic degradation, providing a quantitative basis for reactive power optimization, load dispatching, or three-phase imbalance management in the distribution network, enabling the assessment and early warning of hidden economic losses in the power grid during normal operation.

[0042] S106. Calculate the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current of the normal state monitoring point, and determine the protection setting status of the switchgear based on the zero-sequence impedance. In some embodiments, the zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance, including: S41. Determine the zero-sequence impedance during normal operation based on the amplitude of the zero-sequence voltage and zero-sequence current at the normal state monitoring point; S42. The reference zero-sequence protection setting value of the monitoring terminal is calculated according to the following formula:

[0043] in, This is the accurate zero-sequence protection setting when the monitoring terminal of the k-th line fails; m is the reliability coefficient, typically taken as 1.1~4; This is the rated voltage of the distribution network system; The measured or synthesized zero-sequence current amplitude of the monitoring terminal of the k-th line; The measured or synthesized zero-sequence voltage amplitude of the monitoring terminal of the k-th line; S43. If the deviation between the protection setting value of the switchgear and the reference zero-sequence protection setting value exceeds 30%, the protection setting value of the switchgear is determined to be in an abnormal state; otherwise, it is in a normal state.

[0044] By using the zero-sequence voltage and zero-sequence current measured at the normal state monitoring point under active injection signal, the actual zero-sequence impedance in operation is calculated, and the reference zero-sequence protection setting value that should be set for the line is deduced accordingly. Then, it is compared with the current setting value of the switch equipment. This transforms the protection setting value verification that originally relied on offline calculation or experience estimation into online verification based on real-time active injection test data.

[0045] Since the normal-state monitoring points have eliminated abnormal interference from the measurement circuit, the calculated zero-sequence impedance truly reflects the current zero-sequence parameters of the line, thus the obtained reference setting is highly targeted and timely. This method can effectively detect setting mismatch problems caused by changes in line parameters, grounding method adjustments, or incorrect protection setting, preventing protection devices from failing to operate or maloperating during single-phase grounding faults, and significantly improving the reliability and proactive maintenance level of power distribution system relay protection.

[0046] S107. Establish power grid state evaluation equations, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0047] In some embodiments, obtaining the phase impedance of each monitoring point before establishing the power grid state evaluation equation includes: S51. During normal operation, different power frequency signals are actively injected into the neutral point three times to obtain the measured three-phase voltage and three-phase current at each monitoring point; S52. Solve the following equations to obtain the phase impedance at each monitoring point;

[0048] in, , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is first injected into the neutral point for the first time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is first injected into the neutral point for the first time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the second time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is injected into the neutral point for the second time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the third time; , , The three-phase current vector of the k-th monitoring terminal is obtained when the power frequency signal is injected into the neutral point for the third time. , , These are the phase impedances at the kth monitoring terminal, respectively.

[0049] This embodiment actively injects power frequency signals with different amplitudes and phases into the neutral point three times, and simultaneously collects the three-phase voltage and three-phase current at each monitoring point under each injection. Then, it solves for the impedance of each phase by simultaneously establishing a set of three-phase impedance equations. This overcomes the limitations of traditional methods that can only measure positive-sequence or zero-sequence parameters, achieving online and accurate identification of the independent impedances of phases A, B, and C at each monitoring point in the distribution network. Since the three injected power frequency signals are distinguishable and their amplitudes are controllable, the symmetrical component method can effectively decouple the mutual inductance between the three phases, obtaining high-precision impedance values ​​for each phase. These phase impedances can directly reflect whether there are asymmetrical degradation problems such as line breaks, poor contact, conductor aging, or corrosion. This provides richer and finer-grained characteristic parameters for subsequent power grid condition evaluation equations than a single-sequence component, significantly enhancing the early identification capability of asymmetrical faults and latent defects, while avoiding parameter estimation errors caused by load fluctuations or system disturbances.

[0050] In some embodiments, a power grid state evaluation equation is established to calculate the power grid state in real time and determine whether the power grid state is normal or faulty, including: S61. The power grid state evaluation equations for each monitoring point are established as follows:

[0051] in, , , These are the three-phase voltage vectors of the k-th monitoring terminal obtained in real time; , , These are the three-phase current vectors of the k-th monitoring terminal obtained in real time; The zero-sequence voltage vector of the k-th monitoring terminal is obtained in real time; The zero-sequence current vector of the k-th monitoring terminal is obtained in real time; , , These are the phase impedances at the kth monitoring terminal, respectively; Let be the parallel impedance of the three-phase impedance of the k-th monitoring terminal; S62. Calculate the first obtained vector A according to the following formulas. kSecond obtain vector B k for:

[0052] S63. If the first obtained vector A k Second obtain vector B k The magnitudes of all vectors are not greater than the magnitude threshold, and the first vector A is obtained. k Second obtain vector B k If the absolute value of the phase angle is not greater than the phase angle threshold, it is determined that the power grid after the kth monitoring terminal is in a normal state; otherwise, it is in a fault state. The amplitude threshold is 5mA; the phase angle threshold is 30°.

[0053] This embodiment establishes a power grid state evaluation equation that includes three-phase voltage, three-phase current, zero-sequence voltage, zero-sequence current, and the identified phase impedances and three-phase parallel impedances, and calculates the first obtained vector A based on this equation. k Second obtain vector B k Using the amplitude not exceeding 5mA and the absolute value of the phase angle not exceeding 30° as the normal state criteria, a comprehensive state discrimination model with multiple electrical quantities and multiple constraints was constructed, which integrates the characteristic parameters obtained from all previous steps into a unified equation.

[0054] First obtained vector A k Second obtain vector B k This reflects the deviation between the actual measured value and the theoretical prediction value based on impedance parameters. When both the amplitude and phase angle meet the threshold requirements, it indicates that the power grid is in a symmetrical, stable, and fault-free normal operating state. Once any deviation exceeds the standard, it can be quickly identified as a fault state. This evaluation equation is highly sensitive to anomalies such as asymmetrical faults, high-resistance grounding, open circuits, and sudden load changes.

[0055] Preferably, when the power grid is determined to be in a fault state, the diagnostic section where the fault is located is further determined.

[0056] This application also proposes a novel active sensing system for the operating status of a power distribution system, comprising: Several monitoring terminals are installed on the power distribution line, arranged in order from the power supply side to the load side, to collect the zero-sequence voltage and zero-sequence current at their respective locations; The neutral point active injection device is installed at the neutral point of the power distribution system and is used to actively inject power frequency voltage signals and power frequency current signals into the neutral point of the power distribution system under normal operating conditions. The main data processing platform is connected to multiple monitoring terminals and neutral point active injection devices, including: The data acquisition module is used to acquire the measured zero-sequence voltage and measured zero-sequence current uploaded by each monitoring terminal, as well as the synthesized zero-sequence voltage and calculated zero-sequence current corresponding to each monitoring terminal. The measurement loop status judgment module is used to determine whether the measurement loop status of each monitoring point is normal based on the amplitude deviation and phase angle deviation between the synthesized zero-sequence voltage and the calculated zero-sequence current and the measured zero-sequence voltage and the measured zero-sequence current. The economic evaluation module for operating status is used to determine the economic efficiency of the power grid operating status behind each monitoring terminal by using the ratio of negative sequence current to positive sequence current of the normal state monitoring terminal. The protection setting status judgment module is used to calculate the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current of the normal state monitoring point, obtain an accurate zero-sequence impedance value, and judge the protection setting status of the switchgear.

[0057] The power grid status evaluation module is used to obtain the impedance of each phase of the power grid, establish the power grid status evaluation equation, calculate the power grid status in real time, and determine whether the power grid status is normal or faulty.

[0058] This application also proposes a readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the following steps: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and combined zero sequence voltage and combined zero sequence current are calculated using the symmetrical component method for measuring three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0059] This application also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor in the following steps: Perform the following steps: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and combined zero sequence voltage and combined zero sequence current are calculated using the symmetrical component method for measuring three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

[0060] Those skilled in the art will understand that implementing all or part of the processes in the above embodiments can be accomplished by instructing related hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application's patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. The embodiments disclosed above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made according to the claims of this invention are still within the scope of this invention.

Claims

1. A novel method for actively sensing the operating status of a power distribution system, characterized in that, The method includes: Identify multiple three-phase voltage monitoring points, three-phase current monitoring points, zero-sequence voltage monitoring points, and zero-sequence current monitoring points in the power distribution system. The monitoring points are points set on the power distribution lines that can monitor the voltage of each phase to ground, the voltage current of each phase to ground, and the zero-sequence voltage and zero-sequence current. During normal operation, a power frequency signal is actively injected into the neutral point to obtain the three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current of each monitoring point; The positive sequence voltage, positive sequence current, negative sequence voltage, negative sequence current, and composite zero sequence voltage and composite zero sequence current are calculated using the symmetrical component method for the measurement of three-phase voltage and three-phase current. The state of the monitoring terminal's measurement circuit is assessed as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current. Diagnostic sections are then defined based on the normal state of the monitoring terminal. The economic efficiency of the power grid operation status downstream of each monitoring terminal is determined by using the ratio of negative sequence current to positive sequence current at monitoring points with normal operating status. The zero-sequence impedance during normal operation is calculated using the zero-sequence voltage and zero-sequence current at the normal state monitoring point, and the protection setting status of the switchgear is determined based on the zero-sequence impedance. Establish a power grid state evaluation equation, calculate the power grid state in real time, and determine whether the power grid state is normal or faulty.

2. The novel active sensing method for the operating status of a power distribution system according to claim 1, characterized in that, The process of evaluating the status of the monitoring terminal's measurement circuit as normal or abnormal based on the synthesized zero-sequence voltage, synthesized zero-sequence current, and measured zero-sequence voltage and measured zero-sequence current specifically includes: When the zero-sequence voltage is measured Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ； When the zero-sequence voltage is measured Synthesized zero-sequence voltage The voltage measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ； When the zero-sequence current is measured Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in a normal state when the following formula is met: ； When the zero-sequence current is measured Calculate the zero-sequence current The current measurement circuit of the monitoring terminal is considered to be in an abnormal state when the following formula is met: ； in, To measure zero-sequence voltage; To synthesize the zero-sequence voltage; To measure zero-sequence current; To calculate the zero-sequence current; Mod() is the modulus function; arg() is the phase angle function; P u P is the voltage amplitude deviation threshold; i The current amplitude deviation threshold; A u Voltage phase angle deviation threshold; A i This is the current phase angle deviation threshold. When both the current measurement circuit and the voltage measurement circuit at the monitoring point are in normal condition, the measurement circuit status of the monitoring terminal is determined to be normal; otherwise, the measurement circuit status of the monitoring terminal is determined to be abnormal.

3. The novel active sensing method for the operating status of a power distribution system according to claim 2, characterized in that, The method of determining the economic efficiency of the power grid operation status downstream of each monitoring terminal by using the ratio of negative-sequence current to positive-sequence current at monitoring points in normal operation includes: S31. Calculate the power grid operation economic coefficient at each monitoring terminal of each line, including: in, Let K be the power grid operation economic coefficient at the monitoring terminal of the k-th line. For the negative sequence current component of the monitoring terminal of the k-th line; Let be the positive sequence current component of the monitoring terminal of the k-th line; S32. If the power grid operation economic coefficient at the line monitoring terminal is not greater than the first threshold of power grid operation economic, the power grid operation economic status at the line monitoring terminal is judged to be normal. If the power grid operation economy coefficient at the line monitoring terminal is between the first threshold and the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in an economic attention state. If the power grid operation economy coefficient at the line monitoring terminal is greater than the second threshold of power grid operation economy, the power grid operation economy at the line monitoring terminal is judged to be in a low economic state. The first threshold for the economic efficiency of power grid operation ranges from 1% to 5%; the second threshold for the economic efficiency of power grid operation ranges from 3% to 15%; and the third threshold for the economic efficiency of power grid operation ranges from 15% to 100%.

4. The novel active sensing method for the operating status of a power distribution system according to claim 3, characterized in that, The calculation of the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current at normal monitoring points, and the determination of the protection setting status of the switchgear based on the zero-sequence impedance, includes: S41. Determine the zero-sequence impedance during normal operation based on the amplitude of the zero-sequence voltage and zero-sequence current at the normal state monitoring point; S42. The reference zero-sequence protection setting value of the monitoring terminal is calculated according to the following formula: in, This is the accurate zero-sequence protection setting when the monitoring terminal of the k-th line fails; m is the reliability coefficient, typically taken as 1.1~4; The rated voltage of the power distribution system; The measured or synthesized zero-sequence current amplitude of the monitoring terminal of the k-th line; The measured or synthesized zero-sequence voltage amplitude of the monitoring terminal of the k-th line; S43. If the deviation between the protection setting value of the switchgear and the reference zero-sequence protection setting value exceeds 30%, the protection setting value of the switchgear is determined to be in an abnormal state; otherwise, it is in a normal state.

5. The novel active sensing method for the operating status of a power distribution system according to claim 4, characterized in that, Before establishing the power grid state evaluation equation, the phase impedance of each monitoring point is obtained, including: S51. During normal operation, different power frequency signals are actively injected into the neutral point three times to obtain the measured three-phase voltage and three-phase current at each monitoring point; S52. Solve the following equations to obtain the phase impedance at each monitoring point; in, , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is first injected into the neutral point for the first time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is first injected into the neutral point for the first time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the second time; , , The three-phase current vector of the k-th monitoring terminal is given when the power frequency signal is injected into the neutral point for the second time. , , These are the three-phase voltage vectors of the k-th monitoring terminal when the power frequency signal is injected into the neutral point for the third time; , , The three-phase current vector of the k-th monitoring terminal is obtained when the power frequency signal is injected into the neutral point for the third time. , , These are the phase impedances at the kth monitoring terminal, respectively.

6. The novel active sensing method for the operating status of a power distribution system according to claim 5, characterized in that, The process of establishing a power grid state evaluation equation, calculating the power grid state in real time, and determining whether the power grid state is normal or faulty includes: S61. The power grid state evaluation equations for each monitoring point are established as follows: in, , , These are the three-phase voltage vectors of the k-th monitoring terminal obtained in real time; , , These are the three-phase current vectors of the k-th monitoring terminal obtained in real time; The zero-sequence voltage vector of the k-th monitoring terminal is obtained in real time; The zero-sequence current vector of the k-th monitoring terminal is obtained in real time; , , These are the phase impedances at the kth monitoring terminal, respectively; Let be the parallel impedance of the three-phase impedance of the k-th monitoring terminal; S62. Calculate the first obtained vector Ak and the second obtained vector Bk according to the following formulas: S63. If the first obtained vector A k Second obtain vector B k The amplitudes of all vectors are not greater than the amplitude threshold, and the first obtained vector A k Second obtain vector B k If the absolute value of the phase angle is not greater than the phase angle threshold, it is determined that the power grid after the kth monitoring terminal is in a normal state; otherwise, it is in a fault state. The amplitude threshold is 5mA; the phase angle threshold is 30°.

7. A novel method for actively sensing the operating status of a power distribution system according to claim 6, characterized in that, The zero-sequence voltage and zero-sequence current are obtained by following these steps: Injecting power frequency voltage and current into the neutral point of the power distribution system; Adjust the amplitude of the power frequency voltage and power frequency current so that the neutral point displacement voltage in the power distribution system exceeds the zero-sequence voltage start-up setting value of each monitoring terminal; When the monitoring terminal detects that the zero-sequence voltage exceeds the start-up setting value, the measured zero-sequence voltage and measured zero-sequence current at the injection moment will be used as the measured zero-sequence voltage and measured zero-sequence current.

8. A novel active sensing system for the operating status of a power distribution system, characterized in that, include: Several monitoring terminals are installed on the power distribution line, arranged in order from the power supply side to the load side, to collect the zero-sequence voltage and zero-sequence current at their respective locations; The neutral point active injection device is installed at the neutral point of the power distribution system and is used to actively inject power frequency voltage signals and power frequency current signals into the neutral point of the power distribution system under normal operating conditions. The main data processing platform is communicatively connected to the multiple monitoring terminals and the neutral point active injection device, and includes: The data acquisition module is used to acquire the measured zero-sequence voltage and measured zero-sequence current uploaded by each monitoring terminal, as well as the synthesized zero-sequence voltage and calculated zero-sequence current corresponding to each monitoring terminal. The measurement loop status judgment module is used to determine whether the measurement loop status of each monitoring point is normal based on the amplitude deviation and phase angle deviation between the synthesized zero-sequence voltage and the calculated zero-sequence current and the measured zero-sequence voltage and the measured zero-sequence current. The economic evaluation module for operating status is used to determine the economic efficiency of the power grid operating status behind each monitoring terminal by using the ratio of negative sequence current to positive sequence current of the normal state monitoring terminal. The protection setting status judgment module is used to calculate the zero-sequence impedance during normal operation using the zero-sequence voltage and zero-sequence current of the normal state monitoring point, obtain an accurate zero-sequence impedance value, and judge the protection setting status of the switchgear. The power grid status evaluation module is used to obtain the impedance of each phase of the power grid, establish the power grid status evaluation equation, calculate the power grid status in real time, and determine whether the power grid status is normal or faulty.

9. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, the processor performs the steps of the method as described in any one of claims 1 to 7.

10. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

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