Single-phase earth fault control method and system

Abstract

The invention discloses a single-phase earth fault control method and system, and the method comprises the steps: collecting first zero-sequence voltages, equivalent earth conductance and equivalent earth susceptance of all feeder lines of a power distribution network, analyzing all the first zero-sequence voltages, determining corresponding fault lines, and determining the fault lines; 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 line are collected, the single-line compensation zero-sequence admittance of each fault line is determined, the zero-sequence current and the second zero-sequence voltage of each pole-mounted switch are collected, the zero-sequence admittance of each pole-mounted switch is calculated, and the zero-sequence admittance of each pole-mounted switch is calculated; and determining the fault type of each pole-mounted switch, performing simulation verification on the fault control measure corresponding to each fault line obtained by each fault type, and executing the fault control measure. According to the single-phase earth fault control method and system provided by the embodiment of the invention, the real-time performance of single-phase earth fault control is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a single-phase grounding fault control method and system. Background Art

[0002] Single-phase grounding fault is the most common fault in the power distribution system. It often occurs in humid and rainy weather due to tree barriers, single-phase breakdown of insulators on distribution lines, single-phase line breaks, and small animal hazards. Single-phase grounding not only affects the normal power supply of users, but also may generate overvoltage, burn equipment, and even cause phase-to-phase short circuits to expand accidents. Therefore, controlling single-phase grounding faults is of great significance to ensure stable system operation, power supply reliability, and personal and equipment safety.

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

[0004] It can be seen that how to improve the real-time performance of single-phase grounding fault control has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The present invention provides a single-phase grounding fault control method and system to solve the problem that the existing single-phase grounding fault control technology is difficult to respond quickly to transient faults, resulting in insufficient real-time performance in single-phase grounding fault control, affecting the stability and reliability of the power system, and improving the real-time performance of single-phase grounding fault control.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a single-phase grounding fault control method, which is applied to a flexible grounding device having an active inverter and an arc suppression coil, comprising:

[0007] Collecting the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders in the distribution network, analyzing all the first zero-sequence voltages, and determining the corresponding fault lines;

[0008] Collecting the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculating the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent conductance to ground and the equivalent admittance to ground; calculating the single-line compensation zero-sequence admittance of each fault line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances;

[0009] Collecting the zero-sequence current and the second zero-sequence voltage of the pole switch of each of the fault lines, and calculating the zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage;

[0010] Determine the fault type of each of the pole switches based on the difference characteristics of each of the own zero-sequence admittances and the corresponding single-line compensated zero-sequence admittance;

[0011] A simulation is performed on the fault control measure corresponding to each of the fault lines obtained by each of the fault types, and the fault control measure is executed according to the simulation verification result.

[0012] As one of the preferred solutions, the fault type includes at least an in-zone fault and an out-of-zone fault, and the fault type of each pole switch is determined based on the difference characteristics of each of the own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance, including:

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

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

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

[0016] The fault isolation measures include: closing 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-fault section.

[0018] As one preferred solution, the single-line compensation zero-sequence admittance of each of the faulty lines is calculated according to the linear relationship among the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, including:

[0019]

[0020] Among them, Yb k is the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

[0021] As one of the preferred solutions, the simulation verification of the fault control measures corresponding to each of the fault lines obtained by each of the fault types includes:

[0022] Using power system simulation software to establish a simulation model of the distribution network;

[0023] configuring the parameters and operating status of each of the feeders in the simulation model;

[0024] Setting a fault scenario corresponding to the fault type and the fault line in a simulation model;

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

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

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

[0028] A 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; based on the linear relationship between the equivalent conductance to ground and the equivalent admittance to ground, calculate the third zero-sequence admittance of each feeder; according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, calculate the single-line compensation zero-sequence admittance of each of the fault lines;

[0029] A self-admittance calculation module, used for collecting the zero-sequence current and the second zero-sequence voltage of the pole switch of each of the fault lines, and calculating the self-zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage;

[0030] A fault type judgment module, used to determine the fault type of each of the pole switches based on the difference characteristics of each of the own zero-sequence admittances 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 of the fault lines obtained by each of the fault types, and execute the fault control measures according to the simulation verification results.

[0032] As one of the preferred solutions, the fault type includes at least an in-zone fault and an out-of-zone fault, and the fault type of each pole switch is determined based on the difference characteristics of each of the own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance, including:

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

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

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

[0036] The fault isolation measures include: closing 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-fault section.

[0038] As one preferred solution, the single-line compensation zero-sequence admittance of each of the faulty lines is calculated according to the linear relationship among the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, including:

[0039]

[0040] Among them, Yb k is the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

[0041] As one of the preferred solutions, the simulation verification of the fault control measures corresponding to each of the fault lines obtained by each of the fault types includes:

[0042] Using power system simulation software to establish a simulation model of the distribution network;

[0043] configuring the parameters and operating status of each of the feeders in the simulation model;

[0044] Setting a fault scenario corresponding to the fault type and the fault line in a simulation model;

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

[0046] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0047] (1) collecting the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders in the distribution network, analyzing all the first zero-sequence voltages, and determining the corresponding fault lines; the flexible grounding device has an active inverter and an arc suppression coil, which reversely compensates the resistive current, reactive current and harmonic current from the neutral point to the system, and quickly and fully compensates the grounding current;

[0048] (2) calculating the single-line compensation zero-sequence admittance of each fault 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; collecting the zero-sequence current and the second zero-sequence voltage of the pole switch of each fault line, and calculating the zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage;

[0049] (3) The difference characteristics between the zero-sequence admittance of each pole switch and the single-line compensation zero-sequence admittance of the corresponding fault line are analyzed to determine the fault type of each pole switch. The grounding is judged by the change of zero-sequence admittance before and after the compensation current, thus avoiding the problem of transient faults that cannot be monitored and improving the real-time control of single-phase grounding faults.

[0050] (4) The fault control measures corresponding to each fault line obtained by each fault type are simulated and verified, and the fault control measures are executed according to the simulation verification results, which makes up for the shortcomings of single-phase grounding fault analysis after the traditional neutral point non-effective grounding method is changed. It can quickly perform fault analysis, section positioning and feeder automation protection to ensure the power supply reliability of the distribution line. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow chart of a single-phase grounding fault control method in one embodiment of the present invention;

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

[0053] Figure 3 It is a structural block diagram of a single-phase grounding fault control system in one embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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 ordinary technicians in this field without creative work 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 are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0056] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used in this article are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

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

[0058] An embodiment of the present invention provides a single-phase ground fault control method, which is applied to a flexible grounding device having an active inverter and an arc suppression coil. For details, see Figure 1 , Figure 1 FIG. 1 is a flow chart of a single-phase ground fault control method in one embodiment of the present invention. Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a flexible grounding device in one embodiment of the present invention.

[0059] Step S1: collecting the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders in the distribution network, analyzing all the first zero-sequence voltages, and determining the corresponding fault lines.

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

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

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

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

[0064]

[0065] Among them, Yb k is the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

[0066] Step S3: collecting the zero-sequence current and the second zero-sequence voltage of the pole switches of each fault line, and calculating the zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage.

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

[0068] Step S4: Determine the fault type of each pole switch based on the difference characteristics of each own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance.

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

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

[0071] Step S5: Perform simulation verification on the fault control measures corresponding to each fault line obtained by each fault type, and execute the fault control measures according to the simulation verification results.

[0072] Specifically, the fault control measures include at least fault isolation measures and fault recovery measures. The fault isolation measures are: turning off the corresponding pole switch to isolate the feeder in the fault section; the fault recovery measures are: turning on the corresponding pole switch to restore the normal operation of the feeder in the non-fault section.

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

[0074] Furthermore, 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, fault scenarios corresponding to the fault type and the fault line are set, the corresponding fault scenarios are run in the simulation model, the simulation results of the fault control measures obtained 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 executed.

[0075] Another embodiment of the present invention provides a single-phase ground fault control system, which is applied to a flexible grounding device having an active inverter and an arc suppression coil. For details, see Figure 3 , Figure 3 Shown is a structural block diagram of a single-phase grounding fault control system in one embodiment of the present invention.

[0076] Fault line judgment module 11: used to 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;

[0077] The compensation admittance calculation module 12 is used to collect the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; based on the linear relationship between the equivalent conductance to ground and the equivalent admittance to ground, 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 fault line is calculated;

[0078] Self-admittance calculation module 13: used to collect the zero-sequence current and the second zero-sequence voltage of the pole switch of each fault line, and calculate the self-zero-sequence admittance of each pole 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 each own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance;

[0080] The fault control module 15 is used to simulate and verify the fault control measures corresponding to each fault line obtained by each fault type, and execute the fault control measures according to the simulation verification results.

[0081] Furthermore, in the above embodiment, the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders of the distribution network are collected, all first zero-sequence voltages are analyzed, and corresponding fault lines are determined, including:

[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 conductance to ground and equivalent susceptance to ground of all feeders of the distribution network. When the first zero-sequence voltage of a feeder is greater than a preset voltage threshold, the corresponding feeder is determined to be a fault line.

[0083] Further, in the above embodiment, the calculating of the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent conductance to ground and the equivalent susceptance to ground includes:

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

[0085] Further, in the above embodiment, the calculating of the single-line compensation zero-sequence admittance of each fault line according to the linear relationship among the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances includes:

[0086]

[0087] Among them, Yb kis the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

[0088] Further, in the above embodiment, the calculating of the zero-sequence admittance of each pole 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 pole switch is taken as the corresponding zero-sequence admittance.

[0090] Furthermore, in the above embodiment, the method of determining the fault type of each pole switch based on the difference characteristics of each own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance includes:

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

[0092] Furthermore, in the above embodiment, 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 fault line obtained by each fault type includes:

[0093] A simulation model of the distribution network is established using power system simulation software, parameters and operating status of each feeder are configured in the simulation model, fault scenarios corresponding to the fault type and fault line are set, corresponding fault scenarios are run in the simulation model, 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 according to the second analysis result, and the corresponding fault control measures are executed.

[0094] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A single-phase grounding fault control method, characterized in that: Applied to a flexible grounding device having an active inverter and an arc suppression coil, the method comprises: Collecting the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders in the distribution network, analyzing all the first zero-sequence voltages, and determining the corresponding fault lines; Collecting the first zero-sequence admittance of the active inverter and the second zero-sequence admittance of the arc suppression coil; calculating the third zero-sequence admittance of each feeder based on the linear relationship between the equivalent conductance to ground and the equivalent admittance to ground; calculating the single-line compensation zero-sequence admittance of each fault line according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances; Collecting the zero-sequence current and the second zero-sequence voltage of the pole switch of each of the fault lines, and calculating the zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage; Determine the fault type of each of the pole switches based on the difference characteristics of each of the own zero-sequence admittances and the corresponding single-line compensated zero-sequence admittance; A simulation is performed on the fault control measure corresponding to each of the fault lines obtained by each of the fault types, and the fault control measure is executed according to the simulation verification result.

2. A single-phase grounding fault control method according to claim 1, characterized in that: The fault type includes at least an in-zone fault and an out-of-zone fault, and the determining of the fault type of each pole switch based on the difference characteristics of each of the own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance includes: The absolute value of the difference between each of the self zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance is used as a fault compensation factor of the corresponding pole switch; The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole switch is determined according to the first analysis result.

3. A single-phase grounding fault control method according to claim 1, characterized in that: The fault control measures at least include fault isolation measures and fault recovery measures; The fault isolation measures include: closing 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-fault section.

4. A single-phase grounding fault control method according to claim 1, characterized in that: The calculating the single-line compensation zero-sequence admittance of each of the fault lines according to the linear relationship among the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances comprises: Among them, Yb k is the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

5. A single-phase grounding fault control method according to claim 1, characterized in that: The simulating and verifying the fault control measures corresponding to each of the fault lines obtained by each of the fault types includes: Using power system simulation software to establish a simulation model of the distribution network; configuring the parameters and operating status of each of the feeders in the simulation model; Setting a fault scenario corresponding to the fault type and the fault line in a simulation model; The fault scenario is run in a simulation model, and the obtained simulation results of the fault control measures are analyzed to obtain a second analysis result; and the effectiveness of the fault control measures is verified according to the second analysis result.

6. A single-phase ground fault control system, characterized in that: Applied to a flexible grounding device having an active inverter and an arc suppression coil, the system comprises: A fault line judgment module collects the first zero-sequence voltage, equivalent conductance to ground and equivalent susceptance to ground of all feeders in the distribution network, analyzes all the first zero-sequence voltages, and determines the corresponding fault lines; A 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; based on the linear relationship between the equivalent conductance to ground and the equivalent admittance to ground, calculate the third zero-sequence admittance of each feeder; according to the linear relationship between the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances, calculate the single-line compensation zero-sequence admittance of each of the fault lines; A self-admittance calculation module, used for collecting the zero-sequence current and the second zero-sequence voltage of the pole switch of each of the fault lines, and calculating the self-zero-sequence admittance of each pole switch based on the linear relationship between each zero-sequence current and the corresponding second zero-sequence voltage; A fault type judgment module, used to determine the fault type of each of the pole switches based on the difference characteristics of each of the own zero-sequence admittances 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 of the fault lines obtained by each of the fault types, and execute the fault control measures according to the simulation verification results.

7. A single-phase grounding fault control system according to claim 6, characterized in that: The fault type includes at least an in-zone fault and an out-of-zone fault, and the determining of the fault type of each pole switch based on the difference characteristics of each of the own zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance includes: The absolute value of the difference between each of the self zero-sequence admittance and the corresponding single-line compensation zero-sequence admittance is used as a fault compensation factor of the corresponding pole switch; The fault compensation factor is analyzed to obtain a first analysis result, and the fault type of the corresponding pole switch is determined according to the first analysis result.

8. A single-phase grounding fault control system according to claim 6, characterized in that: The fault control measures at least include fault isolation measures and fault recovery measures; The fault isolation measures include: closing 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-fault section.

9. A single-phase ground fault control system according to claim 6, characterized in that: The calculating the single-line compensation zero-sequence admittance of each of the fault lines according to the linear relationship among the first zero-sequence admittance, the second zero-sequence admittance and all the third zero-sequence admittances comprises: Among them, Yb k is the single line compensation zero-sequence admittance of the kth fault line, Yinv is the first zero-sequence admittance, Yp is the second zero-sequence admittance, n is the number of feeders in the distribution network, Yo j is the third zero-sequence admittance of the j-th feeder, Yo k is the third zero-sequence admittance of the kth fault line.

10. A single-phase ground fault control system according to claim 6, characterized in that: The simulating and verifying the fault control measures corresponding to each of the fault lines obtained by each of the fault types includes: Using power system simulation software to establish a simulation model of the distribution network; configuring the parameters and operating status of each of the feeders in the simulation model; Setting a fault scenario corresponding to the fault type and the fault line in a simulation model; The fault scenario is run in a simulation model, and the obtained simulation results of the fault control measures are analyzed to obtain a second analysis result; and the effectiveness of the fault control measures is verified according to the second analysis result.

Images