A single-phase ground fault control method and system

Abstract

The application discloses a single-phase grounding fault control method and system, wherein the method comprises the following steps: collecting first zero sequence voltages, equivalent ground conductance and equivalent ground susceptance of all feeder lines of a power distribution network; analyzing all the first zero sequence voltages to determine corresponding respective fault lines; collecting first zero sequence susceptances of active inverters, second zero sequence susceptances of arc suppression coils and third zero sequence susceptances of respective feeder lines; determining single-line compensation zero sequence susceptances of each fault line; collecting zero sequence currents and second zero sequence voltages of respective pole switches; calculating self zero sequence susceptances of each pole switch; determining fault types of each pole switch; and simulating and verifying fault control measures corresponding to each fault line obtained by each fault type and executing the fault control measures. The single-phase grounding fault control method and system provided by the embodiment of the application improve the real-time performance of single-phase grounding fault control.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method and system for controlling single-phase grounding faults. Background Technology

[0002] Single-phase grounding faults are the most common faults in power distribution systems, often occurring in humid and rainy weather. They are caused by a variety of factors, including tree obstructions, single-phase insulator breakdown on power lines, single-phase wire breaks, and damage from small animals. Single-phase grounding not only affects the normal power supply to users but can also generate overvoltages, burn out equipment, and even cause phase-to-phase short circuits, escalating the accident. Therefore, controlling single-phase grounding faults is of great significance for ensuring stable system operation, reliable power supply, and the safety of personnel and equipment.

[0003] However, existing single-phase ground fault control technologies are unable to respond quickly to transient faults, resulting in insufficient real-time performance in single-phase ground fault control, which affects the stability and reliability of the power system.

[0004] Therefore, improving the real-time performance of single-phase ground fault control has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a single-phase grounding fault control method and system to solve the problem that existing single-phase grounding fault control technologies are unable to respond quickly to transient faults, resulting in insufficient real-time performance in single-phase grounding fault control, which affects the stability and reliability of the power system, and improves the real-time performance of single-phase grounding fault control.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide a single-phase grounding fault control method, applied to a flexible grounding device with an active inverter and an arc suppression coil, comprising:

[0007] Collect the first zero-sequence voltage, equivalent conductance to ground, and equivalent susceptance to ground of all feeders in the distribution network, analyze all the first zero-sequence voltages, and determine the corresponding fault lines.

[0008] The first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil are collected; based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance, the third zero-sequence admittance of each feeder is calculated; according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, the single-line compensation zero-sequence admittance of each faulted line is calculated.

[0009] Collect the zero-sequence current and second zero-sequence voltage of the pole-mounted switch of each faulty line, and calculate the zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage.

[0010] The fault type of each pole-mounted switch is determined based on the differences between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance.

[0011] The fault control measures corresponding to each faulty line obtained from each of the fault types are simulated and verified, and the fault control measures are executed according to the simulation verification results.

[0012] As one preferred embodiment, the fault types include at least intra-zone faults and inter-zone faults. Determining the fault type of each pole-mounted switch based on the difference between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance includes:

[0013] The absolute value of the difference between each of the self-zero sequence admittance and the corresponding single-line compensated zero sequence admittance is used as the fault compensation factor of the corresponding pole-mounted switch.

[0014] The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

[0015] As one preferred embodiment, the fault control measures include at least fault isolation measures and fault recovery measures;

[0016] The fault isolation measures include: shutting down the corresponding pole-mounted switch to isolate the feeder located in the fault section;

[0017] The fault recovery measures include: opening the corresponding pole-mounted switch to restore the normal operation of the feeder located in the non-faulty section.

[0018] As one preferred embodiment, the step of calculating the single-line compensated zero-sequence admittance for each faulted line based on the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance, and all the third zero-sequence admittances includes:

[0019]

[0020] Among them, Yb k Let Yk be the single-line compensation zero-sequence admittance of the k-th faulty line, Yn be the first zero-sequence admittance, Yp be the second zero-sequence admittance, and n be the number of feeders in the distribution network. j For the third zero-sequence admittance of the j-th feed, Yo k It is the third zero-sequence admittance of the k-th faulty line.

[0021] As one preferred embodiment, the simulation verification of the fault control measures corresponding to each faulty line obtained from each of the fault types includes:

[0022] A simulation model of the distribution network was established using power system simulation software;

[0023] Configure the parameters and operating status of each feeder in the simulation model;

[0024] Set up fault scenarios in the simulation model that correspond to the fault type and the faulty line;

[0025] The fault scenario is run in the simulation model, and the simulation results of the fault control measures are analyzed to obtain a second analysis result; the effectiveness of the fault control measures is verified based on the second analysis result.

[0026] Another embodiment of the present invention provides a single-phase ground fault control system, applied in a flexible grounding device having an active inverter and an arc suppression coil, comprising:

[0027] The fault line identification module collects the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders in the distribution network, analyzes all the first zero-sequence voltages, and determines the corresponding fault lines.

[0028] The compensation admittance calculation module is used to collect the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculate the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance; and calculate the single-line compensation zero-sequence admittance of each faulted line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances.

[0029] The self-admittance calculation module is used to collect the zero-sequence current and the second zero-sequence voltage of the pole-mounted switch of each faulted line, and calculate the self-zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage.

[0030] The fault type determination module is used to determine the fault type of each pole-mounted switch based on the difference characteristics between each of its own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance.

[0031] The fault control module is used to simulate and verify the fault control measures corresponding to each faulty line obtained from each of the fault types, and execute the fault control measures according to the simulation and verification results.

[0032] As one preferred embodiment, the fault types include at least intra-zone faults and inter-zone faults. Determining the fault type of each pole-mounted switch based on the difference between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance includes:

[0033] The absolute value of the difference between each of the self-zero sequence admittance and the corresponding single-line compensated zero sequence admittance is used as the fault compensation factor of the corresponding pole-mounted switch.

[0034] The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

[0035] As one preferred embodiment, the fault control measures include at least fault isolation measures and fault recovery measures;

[0036] The fault isolation measures include: shutting down the corresponding pole-mounted switch to isolate the feeder located in the fault section;

[0037] The fault recovery measures include: opening the corresponding pole-mounted switch to restore the normal operation of the feeder located in the non-faulty section.

[0038] As one preferred embodiment, the step of calculating the single-line compensated zero-sequence admittance for each faulted line based on the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance, and all the third zero-sequence admittances includes:

[0039]

[0040] Among them, Yb k Let Yk be the single-line compensation zero-sequence admittance of the k-th faulty line, Yn be the first zero-sequence admittance, Yp be the second zero-sequence admittance, and n be the number of feeders in the distribution network. j For the third zero-sequence admittance of the j-th feed, Yo k It is the third zero-sequence admittance of the k-th faulty line.

[0041] As one preferred embodiment, the simulation verification of the fault control measures corresponding to each faulty line obtained from each of the fault types includes:

[0042] A simulation model of the distribution network was established using power system simulation software;

[0043] Configure the parameters and operating status of each feeder in the simulation model;

[0044] Set up fault scenarios in the simulation model that correspond to the fault type and the faulty line;

[0045] The fault scenario is run in the simulation model, and the simulation results of the fault control measures are analyzed to obtain a second analysis result; the effectiveness of the fault control measures is verified based on the second analysis result.

[0046] Compared with the prior art, the beneficial effects of the embodiments of the present invention are at least one of the following:

[0047] (1) Collect the first zero-sequence voltage, equivalent ground conductance and equivalent ground susceptance of all feeders in the distribution network, analyze all the first zero-sequence voltages, and determine the corresponding fault lines; the flexible grounding device has an active inverter and an arc suppression coil, and compensates the resistive current, reactive current and harmonic current from the neutral point to the system in reverse, and performs fast full compensation of the grounding current.

[0048] (2) Calculate the single-line compensation zero-sequence admittance of each faulted line based on the linear relationship between the first zero-sequence admittance of the active inverter, the second zero-sequence admittance of the arc suppression coil and the third zero-sequence admittance of each feeder; collect the zero-sequence current and the second zero-sequence voltage of the pole-mounted switch of each faulted line, and calculate the zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage.

[0049] (3) The differences between the zero-sequence admittance of each pole-mounted switch and the single-line compensation zero-sequence admittance of the corresponding fault line are analyzed to determine the fault type of each pole-mounted switch. By analyzing the changes in zero-sequence admittance before and after compensation current, the problem of transient faults not being able to be monitored is avoided, and the real-time control of single-phase ground faults is improved.

[0050] (4) The fault control measures corresponding to each fault line obtained from each fault type are simulated and verified. The fault control measures are executed according to the simulation verification results. This makes up for the shortcomings of single-phase grounding fault judgment after the traditional neutral point non-effective grounding method is modified. It can quickly perform fault judgment, section location and feeder automatic protection, and ensure the power supply reliability of the distribution line. Attached Figure Description

[0051] Figure 1 This is a flowchart illustrating a single-phase grounding fault control method in one embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of a flexible grounding device in one embodiment of the present invention;

[0053] Figure 3 This is a structural block diagram of a single-phase ground fault control system in one embodiment of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0055] In the description of this application, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0056] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. The terms "vertical," "horizontal," "left," "right," "upper," "lower," and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0058] One embodiment of the present invention provides a single-phase grounding fault control method, applied to a flexible grounding device with an active inverter and an arc suppression coil. For details, please refer to [link to relevant documentation]. Figure 1 , Figure 1 The diagram shown illustrates a flowchart of a single-phase ground fault control method according to one embodiment of the present invention. For details, please refer to [link to relevant documentation]. Figure 2 , Figure 2 The diagram shown is a schematic representation of a flexible grounding device in one embodiment of the present invention.

[0059] Step S1: Collect the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders in the distribution network, analyze all the first zero-sequence voltages, and determine the corresponding faulty lines.

[0060] It should be noted that the nodes include several trunk road nodes and several branch road nodes.

[0061] Specifically, voltage sensors, conductivity meters, and impedance analyzers are installed on all feeders of the distribution network to collect the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders. When the first zero-sequence voltage of a feeder is greater than a preset voltage threshold, the corresponding feeder is determined to be a faulty line.

[0062] Step S2: Collect the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculate the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance; calculate the single-line compensation zero-sequence admittance of each faulted line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all third zero-sequence admittances.

[0063] Specifically, the product of the equivalent ground conductance and the preset coefficient for each feeder, plus the equivalent ground susceptance, is used as the corresponding third zero-sequence admittance. The specific calculation formula for the zero-sequence admittance of a single line compensation is as follows:

[0064]

[0065] Among them, Yb k Let Yk be the single-line compensation zero-sequence admittance of the k-th faulty line, Yn be the first zero-sequence admittance, Yp be the second zero-sequence admittance, and n be the number of feeders in the distribution network. j For the third zero-sequence admittance of the j-th feed, Yo k It is the third zero-sequence admittance of the k-th faulty line.

[0066] Step S3: Collect the zero-sequence current and second zero-sequence voltage of the pole-mounted switch for each faulty line. Based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage, calculate the zero-sequence admittance of each pole-mounted switch.

[0067] Specifically, current sensors and voltage sensors are used to collect the zero-sequence current and the second zero-sequence voltage of each pole-mounted switch, and the ratio of the zero-sequence current and the second zero-sequence voltage of each pole-mounted switch is used as its corresponding zero-sequence admittance.

[0068] Step S4: Determine the fault type of each pole switch based on the differences between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance.

[0069] Specifically, the absolute value of the difference between each individual zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance is used as the fault compensation factor for the corresponding pole-mounted switch. The fault compensation factor is analyzed to obtain the first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

[0070] As an embodiment of this application, when the fault compensation factor is less than or equal to a preset threshold, the fault type of the corresponding pole-mounted switch is determined to be an intra-zone fault; otherwise, the fault type of the corresponding pole-mounted switch is determined to be an extra-zone fault.

[0071] Step S5: Simulate and verify the fault control measures corresponding to each faulted line obtained from each fault type, and execute the fault control measures according to the simulation verification results.

[0072] Specifically, fault control measures include at least fault isolation measures and fault recovery measures. Fault isolation measures involve closing the corresponding pole-mounted switch to isolate the feeder located in the faulty section; fault recovery measures involve opening the corresponding pole-mounted switch to restore the normal operation of the feeder located in the non-faulty section.

[0073] As an embodiment of this application, when the fault type of the pole-mounted switch is an intra-zone fault, the corresponding pole-mounted switch is closed to isolate the feeder located in the fault zone; when the fault type of the pole-mounted switch is an inter-zone fault, the corresponding pole-mounted switch is opened to restore the normal operation of the feeder located in the non-fault zone.

[0074] Furthermore, a power system simulation software is used to establish a simulation model of the distribution network. In the simulation model, the parameters and operating status of each feeder are configured, and fault scenarios corresponding to fault types and fault lines are set. The corresponding fault scenarios are run in the simulation model, and the simulation results of the obtained fault control measures are analyzed to obtain a second analysis result. The effectiveness of the fault control measures is verified based on the second analysis result, and the corresponding fault control measures are implemented.

[0075] Another embodiment of the present invention provides a single-phase ground fault control system, applied in a flexible grounding device with an active inverter and an arc suppression coil. For details, please refer to [link to relevant documentation]. Figure 3 , Figure 3 The diagram shown is a structural block diagram of a single-phase ground fault control system according to one embodiment of the present invention.

[0076] Fault line judgment module 11: used to collect the first zero-sequence voltage, equivalent ground conductance and equivalent ground susceptance of all feeders in the distribution network, analyze all the first zero-sequence voltages, and determine the corresponding fault lines.

[0077] Compensation admittance calculation module 12: used to collect the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculate the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance; calculate the single-line compensation zero-sequence admittance of each faulted line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all third zero-sequence admittances.

[0078] Self-admittance calculation module 13: used to collect the zero-sequence current and second zero-sequence voltage of the pole-mounted switch of each faulted line, and calculate the self-zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage.

[0079] Fault type determination module 14: used to determine the fault type of each pole switch based on the difference characteristics of its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance;

[0080] Fault control module 15: Used to simulate and verify the fault control measures corresponding to each faulty line obtained from each fault type, and execute the fault control measures according to the simulation verification results.

[0081] Furthermore, in the above embodiments, the step of collecting the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders in the distribution network, analyzing all the first zero-sequence voltages, and determining the corresponding faulty lines includes:

[0082] Voltage sensors, conductivity meters, and impedance analyzers are installed on all feeders of the distribution network to collect the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders. When the first zero-sequence voltage of a feeder is greater than a preset voltage threshold, the corresponding feeder is determined to be a faulty line.

[0083] Furthermore, in the above embodiments, the calculation of the third zero-sequence admittance of each feeder based on the linear relationship between equivalent ground conductance and equivalent ground susceptance includes:

[0084] The product of the equivalent ground conductance and the preset coefficient of each feeder, plus the equivalent ground susceptance, is used as the corresponding third zero-sequence admittance.

[0085] Furthermore, in the above embodiments, the step of calculating the single-line compensated zero-sequence admittance for each faulted line based on the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance, and all third zero-sequence admittances includes:

[0086]

[0087] Among them, Yb kLet Yk be the single-line compensation zero-sequence admittance of the k-th faulty line, Yn be the first zero-sequence admittance, Yp be the second zero-sequence admittance, and n be the number of feeders in the distribution network. j For the third zero-sequence admittance of the j-th feed, Yo k It is the third zero-sequence admittance of the k-th faulty line.

[0088] Furthermore, in the above embodiments, calculating the self-zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage includes:

[0089] The ratio of the zero-sequence current and the second zero-sequence voltage of each on-pole switch is taken as its corresponding zero-sequence admittance.

[0090] Furthermore, in the above embodiments, determining the fault type of each pole-mounted switch based on the differences between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance includes:

[0091] The absolute value of the difference between each individual zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance is used as the fault compensation factor for the corresponding pole-mounted switch. The fault compensation factor is analyzed to obtain the first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

[0092] Furthermore, in the above embodiments, the fault control measures include at least fault isolation measures and fault recovery measures, and the simulation verification of the fault control measures corresponding to each faulty line obtained from each fault type includes:

[0093] A simulation model of the distribution network is established using power system simulation software. The parameters and operating status of each feeder are configured in the simulation model, and fault scenarios corresponding to fault types and fault lines are set. The corresponding fault scenarios are run in the simulation model, and the simulation results of the obtained fault control measures are analyzed to obtain a second analysis result. The effectiveness of the fault control measures is verified based on the second analysis result, and the corresponding fault control measures are implemented.

[0094] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for controlling single-phase grounding faults, characterized in that, The method, applied to a flexible grounding device with an active inverter and an arc suppression coil, includes: Collect the first zero-sequence voltage, equivalent conductance to ground, and equivalent susceptance to ground of all feeders in the distribution network, analyze all the first zero-sequence voltages, and determine the corresponding fault lines. The first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil are collected; based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance, the third zero-sequence admittance of each feeder is calculated; according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, the single-line compensation zero-sequence admittance of each faulted line is calculated. The step of calculating the single-line compensated zero-sequence admittance for each faulted line based on the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance, and all the third zero-sequence admittances includes: in, For the single-line compensation zero-sequence admittance of the k-th faulty line, For the first zero-sequence admittance, The second zero-sequence admittance is given, where n is the number of feeders in the distribution network. The third zero-sequence admittance of the j-th feeder. The third zero-sequence admittance of the k-th faulty line; Collect the zero-sequence current and second zero-sequence voltage of the pole-mounted switch of each faulty line, and calculate the zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage. The fault type of each pole-mounted switch is determined based on the differences between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance. The fault control measures corresponding to each faulty line obtained from each of the fault types are simulated and verified, and the fault control measures are executed according to the simulation verification results.

2. The single-phase ground fault control method according to claim 1, characterized in that, The fault types include at least intra-zone faults and extra-zone faults. Determining the fault type of each pole-mounted switch based on the difference between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance includes: The absolute value of the difference between each of the self-zero sequence admittance and the corresponding single-line compensated zero sequence admittance is used as the fault compensation factor of the corresponding pole-mounted switch. The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

3. The single-phase ground fault control method according to claim 1, characterized in that, The fault control measures include at least fault isolation measures and fault recovery measures; The fault isolation measures include: shutting down the corresponding pole-mounted switch to isolate the feeder located in the fault section; The fault recovery measures include: opening the corresponding pole-mounted switch to restore the normal operation of the feeder located in the non-faulty section.

4. The single-phase grounding fault control method according to claim 1, characterized in that, The simulation verification of the fault control measures corresponding to each faulty line obtained from each of the fault types includes: A simulation model of the distribution network was established using power system simulation software; Configure the parameters and operating status of each feeder in the simulation model; Set up fault scenarios in the simulation model that correspond to the fault type and the faulty line; The fault scenario is run in the simulation model, and the simulation results of the fault control measures are analyzed to obtain a second analysis result; the effectiveness of the fault control measures is verified based on the second analysis result.

5. A single-phase ground fault control system, characterized in that, A flexible grounding device with an active inverter and an arc suppression coil is applied, the system comprising: The fault line identification module collects the first zero-sequence voltage, equivalent ground conductance, and equivalent ground susceptance of all feeders in the distribution network, analyzes all the first zero-sequence voltages, and determines the corresponding fault lines. The compensation admittance calculation module is used to collect the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculate the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent ground conductance and the equivalent ground susceptance; and calculate the single-line compensation zero-sequence admittance of each faulted line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances. The step of calculating the single-line compensated zero-sequence admittance for each faulted line based on the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance, and all the third zero-sequence admittances includes: in, For the single-line compensation zero-sequence admittance of the k-th faulty line, For the first zero-sequence admittance, The second zero-sequence admittance is given, where n is the number of feeders in the distribution network. The third zero-sequence admittance of the j-th feeder. The third zero-sequence admittance of the k-th faulty line; The self-admittance calculation module is used to collect the zero-sequence current and the second zero-sequence voltage of the pole-mounted switch of each faulted line, and calculate the self-zero-sequence admittance of each pole-mounted switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage. The fault type determination module is used to determine the fault type of each pole-mounted switch based on the difference characteristics between each of its own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance. The fault control module is used to simulate and verify the fault control measures corresponding to each faulty line obtained from each of the fault types, and execute the fault control measures according to the simulation and verification results.

6. A single-phase ground fault control system according to claim 5, characterized in that, The fault types include at least intra-zone faults and extra-zone faults. Determining the fault type of each pole-mounted switch based on the difference between its own zero-sequence admittance and the corresponding single-line compensated zero-sequence admittance includes: The absolute value of the difference between each of the self-zero sequence admittance and the corresponding single-line compensated zero sequence admittance is used as the fault compensation factor of the corresponding pole-mounted switch. The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole-mounted switch is determined based on the first analysis result.

7. A single-phase ground fault control system according to claim 5, characterized in that, The fault control measures include at least fault isolation measures and fault recovery measures; The fault isolation measures include: shutting down the corresponding pole-mounted switch to isolate the feeder located in the fault section; The fault recovery measures include: opening the corresponding pole-mounted switch to restore the normal operation of the feeder located in the non-faulty section.

8. A single-phase ground fault control system according to claim 5, characterized in that, The simulation verification of the fault control measures corresponding to each faulty line obtained from each of the fault types includes: A simulation model of the distribution network was established using power system simulation software; Configure the parameters and operating status of each feeder in the simulation model; Set up fault scenarios in the simulation model that correspond to the fault type and the faulty line; The fault scenario is run in the simulation model, and the simulation results of the fault control measures are analyzed to obtain a second analysis result; the effectiveness of the fault control measures is verified based on the second analysis result.

Images