A method and system for suppressing short-circuit current in a substation

Abstract

The present invention discloses a method and system for suppressing short-circuit current in a substation. The method includes: obtaining the multiple short-circuit current interruption levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation; comparing each of the multiple short-circuit current interruption levels of each circuit breaker with the maximum short-circuit current level interrupted by the circuit breaker one by one; when there is a short-circuit current interruption level exceeding the maximum short-circuit current level, determining the position where the circuit breaker is located as the position where the short-circuit current exceeds the standard; collecting the current values of each circuit breaker at the position where the short-circuit current exceeds the standard, and calculating the current of each fault position branch based on the current values of each circuit breaker; comparing the current of each fault position branch with a preset current-limiting action setting value, and when there is a current of a fault position branch exceeding the current-limiting action setting value, suppressing the short-circuit current in the substation.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more specifically, to a method and system for suppressing short-circuit current in a substation. Background Art

[0002] With the rapid development of the power grid, the scale of the power grid is increasing day by day, and the short-circuit current level in China's power system has been increasing year by year. Excessive short-circuit current will pose hazards to the safe and stable operation of the power system and the electrical equipment itself. To ensure the safe operation of the power system, it is necessary to strengthen or replace the electrical equipment in the power grid to solve the problem caused by the excessive short-circuit current. On the one hand, this will lead to a significant increase in the investment and technical requirements for electrical equipment in the system. In addition, due to the limitation of the breaking capacity of the circuit breaker, there may be a situation where no suitable circuit breaker can be selected. Therefore, to avoid a series of hazards caused by excessive short-circuit current, how to limit the short-circuit current level within the safety margin has become a problem that must be solved in the development of contemporary power grids.

[0003] The conventional control means for short-circuit current adopted in the actual system mainly include line outage, installation of current-limiting reactance, etc. After adopting the above measures, problems such as decreased power supply reliability and increased system loss often occur. The short-circuit current limiter only operates during a fault and has little impact on the normal operation of the system. Conventional fault current limiters are relatively less applied at the 500 kV level, and they are often costly, occupy a large area, and are difficult to promote and apply. Based on the idea of dynamically adjusting the system topology to limit short-circuit current, the above deficiencies can be avoided. For the control strategy of system topology adjustment, currently, it is mainly based on the action strategy of the conventional short-circuit current limiter. By monitoring the current flowing through the limiting device, it is judged whether a fault occurs, and after judging the occurrence of a fault, the current-limiting device is commanded to act. However, the prior art cannot distinguish the specific fault location, resulting in misoperation of the current-limiting device.

[0004] Therefore, a technology is needed to achieve the suppression of short-circuit current in a substation. Summary of the Invention

[0005] The technical solution of the present invention provides a method and system for suppressing short-circuit current in a substation to solve the problem of how to suppress short-circuit current in a substation.

[0006] To solve the above problems, the present invention provides a method for suppressing short-circuit current in a substation, the method comprising:

[0007] Obtaining the short-circuit current breaking levels of each of a plurality of circuit breakers when a fault occurs at different positions in the substation;

[0008] Compare each of the multiple short - circuit current breaking levels of each circuit breaker with the maximum short - circuit current level broken by the circuit breaker one by one; when there is a short - circuit current breaking level exceeding the maximum short - circuit current level, determine the location of the circuit breaker as the location where the short - circuit current exceeds the standard.

[0009] Collect the current values of each circuit breaker at the location where the short - circuit current exceeds the standard, and calculate the current of each fault - location branch based on the current values of each circuit breaker.

[0010] Compare the current of each fault - location branch with a preset current - limiting action setting value. When the current of a fault - location branch exceeds the current - limiting action setting value, suppress the short - circuit current of the substation.

[0011] Preferably, obtaining the multiple short - circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different locations in the substation includes:

[0012] Establish a simulation model based on the operation data of the power system, and perform simulation calculations based on the simulation model to obtain the multiple short - circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different locations in the substation.

[0013] Preferably, preset the current - limiting action setting value:

[0014] The first preset value range is lower than the difference between the maximum short - circuit current level of the circuit breaker and the first margin;

[0015] The second preset value range is higher than the difference between the maximum current of the fault - location branch during a fault in the adjacent substation and the second margin;

[0016] Take the value that simultaneously satisfies the first preset value range and the second preset value range as the current - limiting action setting value.

[0017] Preferably, the comparison of the current of each fault - location branch with the preset current - limiting action setting value includes:

[0018] Determine the fault - current amplitude through the instantaneous value and the current - rising rate of the current of each fault - location branch, and compare the fault - current amplitude with the current - limiting action setting value.

[0019] Preferably, it further includes: when there is no current of a fault - location branch exceeding the current - limiting action setting value, do not suppress the short - circuit current of the substation.

[0020] Based on another aspect of the present invention, the present invention provides a system for suppressing the short - circuit current of a substation. The system includes:

[0021] An initial unit for obtaining the multiple short - circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different locations in the substation;

[0022] A determination unit, configured to compare one by one the multiple short - circuit breaking current levels of each circuit breaker with the maximum short - circuit current level broken by the circuit breaker; when there is a short - circuit breaking current level exceeding the maximum short - circuit current level, the position where the circuit breaker is located is determined as the position where the short - circuit current exceeds the standard.

[0023] A calculation unit, configured to collect the current values of each circuit breaker at the position where the short - circuit current exceeds the standard, and calculate the current of each fault - position branch based on the current values of each circuit breaker.

[0024] A result unit, configured to compare the current of each fault - position branch with a preset current - limiting action setting value, and when there is a current of a fault - position branch exceeding the current - limiting action setting value, suppress the short - circuit current of the substation.

[0025] Preferably, the initial unit is specifically configured to:

[0026] Establish a simulation model according to the operation data of the power system, and perform simulation calculations based on the simulation model to obtain the multiple short - circuit breaking current levels of each circuit breaker among multiple circuit breakers when a fault occurs at different positions of the substation.

[0027] Preferably, the result unit is specifically configured to preset the current - limiting action setting value:

[0028] The first preset value range is lower than the difference between the maximum short - circuit current level of the circuit breaker and the first margin.

[0029] The second preset value range is higher than the difference between the maximum current of the fault - position branch during a fault in the adjacent substation and the second margin.

[0030] The value that simultaneously satisfies the first preset value range and the second preset value range is used as the current - limiting action setting value.

[0031] Preferably, the comparison of the current of each fault - position branch with the preset current - limiting action setting value includes:

[0032] Determine the fault - current amplitude through the instantaneous value and the current - rising rate of the current of each fault - position branch, and compare the fault - current amplitude with the current - limiting action setting value.

[0033] Preferably, it further includes: when there is no current of a fault - position branch exceeding the current - limiting action setting value, the short - circuit current of the substation is not suppressed.

[0034] The technical solution of the present invention provides a method and a system for suppressing short-circuit current in a substation. The method includes: obtaining the multiple short-circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation; comparing the multiple short-circuit current breaking levels with the maximum short-circuit current level that the circuit breaker can break one by one; when there is a short-circuit current breaking level exceeding the maximum short-circuit current level, determining the position where the circuit breaker is located as the position where the short-circuit current exceeds the standard; collecting the current values of each circuit breaker at the position where the short-circuit current exceeds the standard, and calculating the current of each fault position branch based on the current values of each circuit breaker; comparing the current of each fault position branch with a preset current limiting action setting value, and when there is a fault position branch whose current exceeds the current limiting action setting value, suppressing the short-circuit current in the substation. The present invention proposes a control strategy for current limiting in a substation. By calculating and analyzing, it determines the fault positions of the outgoing lines where the short-circuit current exceeds the standard, collects the currents of each branch in the substation, and commands the current limiting action when it is judged that the branch current exceeds the standard under fault conditions, avoiding unnecessary current limiting actions and reducing the impact on the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0036] Figure 1 FIG. is a flowchart of a method for suppressing short-circuit current in a substation according to a preferred embodiment of the present invention;

[0037] Figure 2 FIG. is a schematic diagram of the application of a current limiting device in a typical 500 kV system according to a preferred embodiment of the present invention;

[0038] Figure 3 FIG. is a schematic diagram of the wiring of a typical 500 kV substation according to a preferred embodiment of the present invention;

[0039] Figure 4 FIG. is a schematic diagram of the control device of a 500 kV substation current limiting device according to a preferred embodiment of the present invention;

[0040] Figure 5 FIG. is a schematic diagram of the application of a current limiting device in a typical 500 kV system according to a preferred embodiment of the present invention;

[0041] Figure 6 FIG. is a schematic diagram of the wiring of a 500 kV substation according to a preferred embodiment of the present invention;

[0042] Figure 7 FIG. is a schematic diagram of the application of short-circuit current suppression according to a preferred embodiment of the present invention; and

[0043] Figure 8 FIG. is a system structure diagram of a method for suppressing short-circuit current in a substation according to a preferred embodiment of the present invention. Detailed Implementation Modes

[0044] Reference is now made to the accompanying drawings to describe exemplary embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not intended to limit the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0045] Unless otherwise specified, the terms used herein (including scientific and technical terms) have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields, and should not be understood as idealized or overly formal meanings.

[0046] Figure 1 FIG. 10 is a flowchart of a method for suppressing short-circuit current in a substation according to a preferred embodiment of the present invention. When a short-circuit grounding fault occurs in the power system, a short-circuit current will pass through the fault point. When the short-circuit current level exceeds the breaking capacity of the circuit breaker, the short circuit may not be interrupted. The current-limiting device generally monitors the current passing through itself. However, this method cannot distinguish the specific fault location. In an actual power system, the short-circuit current levels interrupted by the circuit breaker are different under different fault locations. The above method will cause the current-limiting device to still operate under the condition that the short-circuit current does not exceed the standard, increasing the unnecessary operation times.

[0047] The present invention proposes a control strategy and device for a current-limiting device in a substation, determines the fault location of the outgoing line with an excessive short-circuit current through calculation and analysis, judges the fault location by collecting the currents of each branch in the substation, and commands the current-limiting device to operate when the short-circuit current exceeds the standard under the fault condition, avoiding unnecessary operation of the current-limiting device and reducing the impact on the system.

[0048] As Figure 1 shown, the present invention provides a method for suppressing short-circuit current in a substation, and the method includes:

[0049] Step 101: Obtain the short-circuit current breaking levels of each of a plurality of circuit breakers when faults occur at different positions in the substation; preferably, it includes: establishing a simulation model based on the operation data of the power system, and performing simulation calculations based on the simulation model to obtain the short-circuit current breaking levels of each of a plurality of circuit breakers when faults occur at different positions in the substation.

[0050] Step 102: Compare the multiple short - circuit breaking current levels of each circuit breaker with the maximum short - circuit current level broken by the circuit breaker one by one; when there is a short - circuit breaking current level exceeding the maximum short - circuit current level, determine the position of the circuit breaker as the position where the short - circuit current exceeds the standard.

[0051] Step 103: Collect the current values of each circuit breaker at the position where the short - circuit current exceeds the standard, and calculate the current of each fault - position branch based on the current values of each circuit breaker.

[0052] Step 104: Compare the current of each fault - position branch with a preset current - limiting action setting value. When the current of a fault - position branch exceeds the current - limiting action setting value, suppress the short - circuit current of the substation.

[0053] Preferably, it further includes: presetting the current - limiting action setting value:

[0054] The first preset value range is lower than the difference between the maximum short - circuit current level of the circuit breaker and the first margin.

[0055] The second preset value range is higher than the difference between the maximum current of the fault - position branch during a fault in the adjacent substation and the second margin.

[0056] Take the value that simultaneously satisfies the first preset value range and the second preset value range as the current - limiting action setting value.

[0057] Preferably, comparing the current of each fault - position branch with the preset current - limiting action setting value includes:

[0058] Determine the fault - current amplitude through the instantaneous value and the current - rising rate of the current of each fault - position branch, and compare the fault - current amplitude with the current - limiting action setting value.

[0059] Preferably, it further includes: when there is no current of a fault - position branch exceeding the current - limiting action setting value, do not suppress the short - circuit current of the substation.

[0060] The schematic diagram of the application of the current - limiting device in the typical 500kV system of the present invention is as Figure 2 shown. The schematic diagram of the wiring of the typical 500kV substation is as Figure 3 shown.

[0061] The control strategy for the current - limiting device in the substation proposed by the present invention includes:

[0062] Determine the fault type and fault position where the short - circuit current exceeds the standard by calculation;

[0063] First, according to the system operation data, establish a detailed simulation model considering the substation wiring topology, consider the different action time sequences of the circuit breakers, and calculate the short - circuit breaking current levels when faults occur at different positions.

[0064] Compare the calculated breaker interrupting current level with the breaker interrupting capacity. If it exceeds the breaker interrupting capacity, then the fault location is the location where the short-circuit current exceeds the standard. For example, Figure 3 As shown, typical fault locations include: Bus 1, Bus 2, Branches L1 - L6.

[0065] This invention collects the switch currents in the substation, calculates the fault branch current, and determines whether a short-circuit current exceeding the standard fault has occurred.

[0066] This invention collects the current of each breaker in the substation. For CBx, its current is i CBx , and the current direction can be as Figure 3 shown.

[0067] According to the collected breaker currents, calculate the fault branch current of the short-circuit current exceeding the standard location determined in the above steps; where:

[0068] The fault current of Bus 1, i FM1 = i CB1 + i CB4 + i CB7 ;

[0069] The fault current of Bus 2, i FM2 = i CB3 + i CB7 + i CB9 ;

[0070] The fault current of Branch 1, i FM2 = i CB2 - i CB1 , and so on for other branches.

[0071] This invention judges the fault current amplitude through the instantaneous value and rising rate of the fault current of each branch, and compares it with the action setting value. When the action setting value requirement is met, it is judged that a short-circuit current exceeding the standard fault has occurred, and the current-limiting device acts; otherwise, it does not act.

[0072] The determination of the fault current action setting value Iset of this invention considers the following factors:

[0073] The action setting value is lower than the breaker interrupting capacity and has a certain margin.

[0074] The action setting value is greater than the maximum branch current during a fault in the adjacent substation and has a certain margin to ensure that it does not act during a fault in the adjacent substation.

[0075] Within the above range, take the relatively lower value.

[0076] Figure 4 is a schematic diagram of the control device of the current-limiting device for a 500 kV substation according to the preferred embodiment of this invention. As Figure 4As shown, the control device of the substation current-limiting device specifically includes the following parts:

[0077] Acquisition unit: It acquires the electrical quantities of substation voltage and current, and the status of switchgear in real time.

[0078] System calculation unit: According to the system operation mode and the operation status of substation equipment, it calculates the fault exceeding-standard branch and the action setting value in real time, and provides them to the judgment unit. This part can be implemented by real-time calculation and real-time update, or by off-line calculation and early input.

[0079] Judgment unit: Based on the acquired current, it calculates the current of each branch and compares it with the action setting value to judge whether a fault of short-circuit current exceeding the standard occurs.

[0080] Control unit: It sends control commands according to the judgment of whether a fault occurs.

[0081] The schematic diagram of the wiring principle of the current-limiting device applied to the typical 500 kV system provided by the present invention is as Figure 5 shown. Among them, when a short-circuit fault occurs at substation A, the maximum short-circuit current is 70 kA, and when a fault occurs at substation B, the maximum short-circuit current is 55 kA. Among them, the short-circuit current at substation A exceeds the breaking capacity of the circuit breaker at substation A, and limiting measures need to be taken. It is considered to install a current-limiting device at the outgoing line from substation A to substation B.

[0082] When the present invention adopts the conventional control strategy, the current flowing through the current-limiting device is used as the fault criterion. When a fault occurs at substation A, the fault current on the A-B line is 15 kA. In order to ensure the reliable operation of the current limiter, the fault current action setting value should be lower than 15 kA. When a fault occurs at substation B, the fault current on the A-B line is 25 kA, which exceeds the action setting value. Although the short-circuit current at substation B does not exceed the standard, the current-limiting device still operates at this time. In addition, when a fault occurs near substation B on the outgoing line of substation B, the fault current on the A-B line may still exceed 15 kA, and when a fault occurs on the outgoing line of substation B, the current-limiting device may also operate. It can be seen that when adopting the conventional strategy, it is impossible to distinguish whether the current at the fault location exceeds the standard, resulting in unnecessary operation of the current-limiting device.

[0083] When adopting the control strategy proposed by the present invention, first according to system calculation, when a fault occurs at the bus and each branch of the substation, the breaking current level of the circuit breaker exceeds its breaking capacity. Therefore, the current of each branch and the bus are used as fault judgment quantities.

[0084] Further calculations show that the maximum fault current of the branch is 70 kA, while when a fault occurs at the adjacent substation, the maximum short-circuit current of the branch is 25 kA. Considering the above factors, the fault current action setting value is selected as 35 kA. When a fault occurs at the bus or the outgoing line branch of substation A, the branch current at the fault location exceeds 35 kA, which can ensure the reliable operation of the current-limiting device. When a fault occurs at the adjacent substation B, the maximum current of the branch does not exceed 25 kA, which can avoid unnecessary operation of the current-limiting device.

[0085] Table 2 Application Effect

[0086]

[0087]

[0088] Figure 7 The best example of the application is given. Taking the typical wiring of a 500 kV substation as an example, a fast-breaking device is installed on the outgoing line 1 branch. Under normal operating conditions, the fast current-limiting device is closed. When a short-circuit fault occurs in the substation, the fast current-limiting device is first opened to limit the short-circuit current. After the fault is cleared, the fast current-limiting device is closed to restore the normal operation of the system.

[0089] Figure 8 This is a system structure diagram for suppressing the short-circuit current of a substation according to a preferred embodiment of the present invention. As Figure 8 shown, the present invention provides a system for suppressing the short-circuit current of a substation, the system includes:

[0090] An initial unit 801, configured to obtain the multiple short-circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation;

[0091] Preferably, the initial unit 801 is further configured to:

[0092] Establish a simulation model according to the operation data of the power system, and perform simulation calculations based on the simulation model to obtain the multiple short-circuit current breaking levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation.

[0093] A determination unit 802, configured to compare the multiple short-circuit current breaking levels of each circuit breaker with the maximum short-circuit current level broken by the circuit breaker one by one; when there is a short-circuit current breaking level exceeding the maximum short-circuit current level, determine the position where the circuit breaker is located as the position where the short-circuit current exceeds the standard;

[0094] A calculation unit 803, configured to collect the current values of each circuit breaker at the position where the short-circuit current exceeds the standard, and calculate the current of each fault position branch based on the current values of each circuit breaker;

[0095] A result unit 804, configured to compare the current of each fault position branch with a preset current-limiting action setting value, and when there is a current of a fault position branch exceeding the current-limiting action setting value, suppress the short-circuit current of the substation.

[0096] Preferably, the result unit 804 is specifically configured to: preset the current-limiting action setting value:

[0097] The first preset value range is lower than the difference between the maximum short-circuit current level of the circuit breaker and the first margin;

[0098] The second preset value range is higher than the difference between the maximum current of the fault location branch when a fault occurs in the adjacent substation and the second margin;

[0099] The value that simultaneously satisfies the first preset value range and the second preset value range is used as the current-limiting action setting value.

[0100] Preferably, comparing the current of each fault location branch with the preset current-limiting action setting value includes:

[0101] Determining the fault current amplitude through the instantaneous value and the current rise rate of the current of each fault location branch, and comparing the fault current amplitude with the current-limiting action setting value.

[0102] Preferably, it further includes: when there is no current of the fault location branch exceeding the current-limiting action setting value, the short-circuit current of the substation is not suppressed.

[0103] A system 800 for suppressing the short-circuit current of a substation according to a preferred embodiment of the present invention corresponds to a method 100 for suppressing the short-circuit current of a substation according to a preferred embodiment of the present invention, and will not be elaborated here.

[0104] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0105] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 one process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0106] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more of the procedures Figure 1 one or more procedures and / or blocks Figure 1 specified in a block or blocks.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the procedures Figure 1 one or more procedures and / or blocks Figure 1 specified in a block or blocks.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the scope of its protection. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent replacements to the specific implementation manners of the invention, but these changes, modifications or equivalent replacements are all within the scope of the claims of the invention pending approval.

[0109] The present invention has been described by reference to a few embodiments. However, as is well known to those skilled in the art, other embodiments equivalent to those disclosed above of the present invention equally fall within the scope of the present invention as defined by the appended patent claims.

[0110] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless otherwise clearly defined therein. All references to "a / the [device, component, etc.]" are to be construed openly as at least one instance of the device, component, etc., unless otherwise clearly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless clearly stated.

Claims

1. A method for suppressing short - circuit current in a substation, the method comprising: Obtaining the multiple short - circuit current interruption levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation, including: Establishing a simulation model based on the operation data of the power system, and performing simulation calculations based on the simulation model to obtain the multiple short - circuit current interruption levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation; Comparing each of the multiple short - circuit current interruption levels with the maximum short - circuit current level that the circuit breaker can interrupt one by one; when there is a short - circuit current interruption level exceeding the maximum short - circuit current level, determining the position where the circuit breaker is located as the position where the short - circuit current exceeds the standard; Collecting the current values of each circuit breaker at the position where the short - circuit current exceeds the standard, and calculating the current of each fault - position branch based on the current values of each circuit breaker; Presetting the current - limiting action setting value: The first preset value range is lower than the difference between the maximum short - circuit current level of the circuit breaker and the first margin; The second preset value range is higher than the difference between the maximum current of the fault - position branch during a fault in the adjacent substation and the second margin; Taking the value that simultaneously satisfies the first preset value range and the second preset value range as the current - limiting action setting value; Comparing the current of each fault - position branch with the preset current - limiting action setting value, and when there is a current of a fault - position branch exceeding the current - limiting action setting value, suppressing the short - circuit current in the substation.

2. According to the method of claim 1, comparing the current of each fault - position branch with the preset current - limiting action setting value includes: Determining the fault - current amplitude through the instantaneous value and the current - rising rate of the current of each fault - position branch, and comparing the fault - current amplitude with the current - limiting action setting value.

3. The method according to claim 1, further comprising: When there is no current of a fault - position branch exceeding the current - limiting action setting value, not suppressing the short - circuit current in the substation.

4. A system for suppressing short - circuit current in a substation, the system comprising: An initial unit for obtaining the multiple short - circuit current interruption levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation; The initial unit is specifically used for: Establishing a simulation model based on the operation data of the power system, and performing simulation calculations based on the simulation model to obtain the multiple short - circuit current interruption levels of each circuit breaker among multiple circuit breakers when faults occur at different positions in the substation; A determination unit for comparing each of the multiple short - circuit current interruption levels of each circuit breaker with the maximum short - circuit current level that the circuit breaker can interrupt one by one; when there is a short - circuit current interruption level exceeding the maximum short - circuit current level, determining the position where the circuit breaker is located as the position where the short - circuit current exceeds the standard; A calculation unit for collecting the current values of each circuit breaker at the position where the short - circuit current exceeds the standard, and calculating the current of each fault - position branch based on the current values of each circuit breaker; The result unit is specifically used for presetting the current limiting action setting value: the first preset value range is lower than the difference between the maximum short-circuit current level of the circuit breaker and the first margin; the second preset value range is higher than the difference between the maximum current of the fault location branch when a fault occurs in the adjacent substation and the second margin; the value that simultaneously satisfies the first preset value range and the second preset value range is used as the current limiting action setting value; The result unit is used to compare the current of each fault location branch with the preset current limiting action setting value, and when the current of a fault location branch exceeds the current limiting action setting value, suppress the short-circuit current of the substation.

5. The system according to claim 4, wherein comparing the current of each fault location branch with the preset current limiting action setting value includes: Determining the fault current amplitude through the instantaneous value and the current rising rate of the current of each fault location branch, and comparing the fault current amplitude with the current limiting action setting value.

6. The system according to claim 4, further comprising: When there is no current of a fault location branch exceeding the current limiting action setting value, the short-circuit current of the substation is not suppressed.

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