Method for setting action value of flexible short-circuit current suppression of power grid

Abstract

This invention relates to the field of power system technology, specifically providing a method for setting the operating settings of flexible suppression of short-circuit current in a power grid. The method includes: acquiring the topology and grid parameters of the target voltage side of a target substation; dividing the flexible suppression zone into an area within and outside the zone based on the topology; when a short circuit occurs outside the zone, performing short-circuit calculations based on the first short-circuit fault point to obtain the first short-circuit current flowing through the outgoing line, calculating the phasor sum, and determining the lower limit of the operating settings of the fast circuit breaker; when a short circuit occurs within the zone, performing short-circuit calculations based on the second short-circuit fault point to obtain the second short-circuit current, calculating the phasor sum, and determining the upper limit of the operating settings of the fast circuit breaker; and determining the operating settings of the fast circuit breaker based on the upper and lower limits of the operating settings. This method addresses the problem in related technologies where flexible suppression of short-circuit current may malfunction when the fault point is located outside the target voltage side of the substation, affecting grid operation.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method for setting the action setting value for flexible suppression of short-circuit current in power grids. Background Technology

[0002] With the rapid development of the power grid and the increasing installed capacity of the system, the electrical connections of the power grid have become closer, leading to a continuous rise in short-circuit current levels and the generation of excessive short-circuit currents, which pose a serious threat to the safe and stable operation of the power system and electrical equipment.

[0003] To suppress excessive short-circuit current, related technologies employ flexible short-circuit current suppression by using a fast circuit breaker to disconnect some branches after a short-circuit fault occurs and before the conventional circuit breaker trips, thereby changing the power grid topology and reducing the short-circuit current to within the circuit breaker's breaking capacity. This achieves the technical effect of improving transmission capacity without weakening the grid structure.

[0004] However, the short-circuit current flexible suppression action setting method in related technologies is based solely on the short-circuit current amplitude of local nodes. This requires pre-forming a list of fault locations exceeding the standard through short-circuit calculations, and then calculating the action setting based on this list. This process is computationally intensive and complex. At the same time, related technical solutions do not fully consider selectivity requirements. Relying solely on a single current amplitude threshold makes it difficult to accurately distinguish whether a fault occurs near the target voltage side of the substation or in an adjacent substation or at another voltage level. This can lead to the rapid circuit breaker malfunctioning even when the short-circuit current on the target voltage side of the substation does not exceed the standard, causing unnecessary changes to the power grid topology and affecting the normal operation of the power grid and the reliability of power supply.

[0005] There is currently no effective solution to the problem that flexible suppression of short-circuit current in related technologies may malfunction when the fault point is located outside the target voltage side of the substation, thus affecting the operation of the power grid. Summary of the Invention

[0006] The present invention provides a method for setting the action setting value of flexible suppression of short-circuit current in power grids, which at least solves the problem in related technologies that flexible suppression of short-circuit current may malfunction when the fault point is located in an area outside the target voltage side of the substation, thus affecting the operation of the power grid.

[0007] According to one aspect of the present invention, a method for setting the operating setting value for flexible suppression of short-circuit current in a power grid is provided, comprising: acquiring power grid parameters and the topology of a target voltage side in a target substation, wherein, in the event of a short circuit on the target voltage side of the target substation, flexible suppression of short-circuit current is performed using a corresponding operating setting value; dividing a flexible suppression zone into an area within and an area outside the zone based on the topology, wherein the flexible suppression zone includes a fast circuit breaker, and flexible suppression of short-circuit current is performed by controlling the operation of the fast circuit breaker; in the event of a short circuit outside the zone, based on the power grid parameters and a first short-circuit fault outside the zone... A short-circuit calculation is performed to obtain the first short-circuit current flowing through the outgoing line. The phasor sum of the first short-circuit current is calculated to determine the lower limit of the operating setting of the fast circuit breaker. The outgoing line is a transmission line on the target voltage side bus used to output electrical energy from the target substation. In the event of a short circuit within the area, a short-circuit calculation is performed based on the grid parameters and the second short-circuit fault point within the area to obtain the second short-circuit current flowing through the outgoing line. The phasor sum of the second short-circuit current is calculated to determine the upper limit of the operating setting of the fast circuit breaker. The operating setting of the fast circuit breaker is determined based on the upper and lower limits of the operating setting.

[0008] As an optional approach, in the event of a short circuit outside the designated area, short circuit calculations are performed based on the grid parameters and the first short circuit fault point outside the designated area to obtain the first short circuit current flowing through the outgoing line. The phasor sum of the first short circuit current is calculated, and the lower limit of the operating setting of the fast circuit breaker is determined. This includes: the first short circuit fault point includes fault points on other voltage-side buses in the target substation besides the target voltage-side bus, and fault points on buses connected to the target substation from adjacent substations; the first short circuit current has the positive direction from the target voltage-side bus to the outgoing line; the first phasor sum of the first short circuit current is obtained by calculating and summing the phasors of each first short circuit current; a first coefficient is determined based on the voltage level of the target voltage side and the relay protection setting requirements; and the lower limit of the operating setting is calculated using the operating setting lower limit calculation formula based on the maximum effective value of the first phasor sum and the first coefficient.

[0009] As an optional solution, the formula for calculating the lower limit of the action setpoint is as follows: I set_min = k1*I1; where I set_min It represents the lower limit of the action setpoint; k1 represents the first coefficient; I1 represents the maximum effective value of the first phasor sum.

[0010] As an optional approach, in the event of a short circuit within the area, short circuit calculations are performed based on the grid parameters and the second short-circuit fault point within the area to obtain the second short-circuit current flowing through the outgoing line. The phasor sum of the second short-circuit current is calculated, and the upper limit of the operating setting of the fast circuit breaker is determined. This includes: the second short-circuit fault point includes a fault point on the target voltage side bus and a fault point at the beginning of the outgoing line, wherein the beginning of the outgoing line is a line section within a preset length range along the outgoing line extension direction starting from the target voltage side bus; the second short-circuit current is positively directed from the bus to the outgoing line; the second phasor sum of the second short-circuit current is obtained by calculating and summing the phasors of each second short-circuit current; a second coefficient is determined based on the voltage level of the target voltage side and the relay protection setting requirements; a third coefficient is determined based on the ratio of the effective value of the bus short-circuit current to the circuit breaker breaking current under the maximum operating mode of the target substation; and the upper limit of the operating setting is calculated using the formula for calculating the upper limit of the operating setting based on the minimum value of the second phasor sum, the second coefficient, and the third coefficient.

[0011] As an optional approach, the formula for calculating the upper limit of the action setpoint is as follows: I set_max =I² / (k² * k³); where I set_max I1 represents the upper limit of the action setpoint; I2 represents the minimum value of the second phasor and the effective value; k2 represents the second coefficient, and k3 represents the third coefficient.

[0012] As an optional approach, the short-circuit current flexible suppression zone is divided into an inner and outer zone according to the topology, including: dividing the outgoing line and the target voltage side bus into the inner zone according to the topology; dividing the other voltage side buses in the target substation other than the target voltage side bus, and other substations outside the target substation into the outer zone.

[0013] As an optional approach, the final action setting value is determined based on the upper limit and the lower limit of the action setting value, including: simulating possible interference factors of the actual short-circuit current through simulation or dynamic model testing to obtain the actual current carrying range that the short-circuit current flexible suppression device can accurately measure; wherein, the short-circuit current flexible suppression device includes a fast circuit breaker; the action setting value is determined based on the upper limit and the lower limit of the action setting value, combined with the actual current carrying range.

[0014] As an optional approach, after determining the operating setpoint of the fast circuit breaker based on the upper limit and the lower limit of the operating setpoint, the method further includes: storing the operating setpoint; collecting the short-circuit current flowing through the outgoing line in real time and calculating the effective value of the phasor sum of the short-circuit current; and controlling the fast circuit breaker to perform flexible suppression of the short-circuit current when the effective value of the phasor sum is greater than the operating setpoint.

[0015] According to another aspect of the present invention, an electronic device is also provided, comprising: a processor, and a memory storing a program, the program including instructions that, when executed by the processor, cause the processor to perform the method according to any one of the preceding claims.

[0016] According to another aspect of the invention, a non-transitory machine-readable medium storing computer instructions for causing the computer to perform the method according to any one of the preceding claims is also provided.

[0017] According to another aspect of the present invention, a computer program product is also provided, comprising a computer program / instructions that, when executed by a processor, implement the method described in any of the preceding claims.

[0018] The proposed invention provides a method for setting the operating setting value for flexible short-circuit current suppression in power grids. This method clearly divides the protection range of flexible short-circuit current suppression technology into an internal and external zone. Based on the most severe fault point outside the zone, a phasor is calculated to obtain the lower limit of the operating setting value. This ensures that when a short circuit occurs outside the zone, the current will necessarily be less than the operating setting value, and the fast circuit breaker will reliably not operate. Conversely, based on the least severe fault point within the zone, a phasor is calculated to obtain the upper limit of the operating setting value. This ensures that when a short circuit occurs within the zone, the current flowing through the outgoing line will necessarily be greater than the operating setting value, and the fast circuit breaker will reliably operate. By setting the operating setting value within the interval formed by the upper and lower limits, a single setting value can simultaneously cover both busbar faults and line faults. This achieves selective protection where the fault point is reliable within the zone and reliable non-operation is not required outside the zone. This solves the problem in related technologies where flexible short-circuit current suppression may malfunction when the fault point is located outside the target voltage side of the substation, affecting power grid operation. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other embodiments based on these drawings without creative effort.

[0020] Figure 1This is a flowchart of the power grid short-circuit current flexible suppression operation setting method according to an embodiment of the present invention.

[0021] Figure 2 This is a wiring diagram of the target substation according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the electronic device created by this invention. Detailed Implementation

[0023] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0024] However, the setting of the action value for flexible suppression of short-circuit current in related technologies does not fully consider the selectivity requirements. When there is a short-circuit current in the power grid that does not exceed the standard, the flexible suppression device may be misjudged as a fault in the area and triggered to operate, resulting in unnecessary changes to the power grid topology. In other words, there is a problem of insufficient selectivity, which affects the normal operation of the power grid and the reliability of power supply.

[0025] To address the issue that flexible short-circuit current suppression in related technologies may malfunction when the fault point is located outside the target voltage side of the substation, thus affecting grid operation, the embodiments of this invention provide a method for setting the operating setting value of flexible short-circuit current suppression in the power grid, such as... Figure 1 As shown, it includes:

[0026] Step S101: Obtain the grid parameters and the topology of the target voltage side in the target substation. In the event of a short circuit, the target voltage side of the target substation uses the corresponding action setting to flexibly suppress the short circuit current.

[0027] Step S102: Divide the short-circuit current flexible suppression zone into an inner zone and an outer zone according to the topology. The short-circuit current flexible suppression zone includes a fast circuit breaker. By controlling the operation of the fast circuit breaker, the short-circuit current is flexibly suppressed.

[0028] Step S103: In the event of a short circuit outside the zone, short circuit calculation is performed based on the grid parameters and the first short circuit fault point outside the zone to obtain the first short circuit current flowing through the outgoing line, calculate the phasor sum of the first short circuit current, and determine the lower limit of the operating setting of the fast circuit breaker; wherein, the outgoing line is the transmission line on the target voltage side bus used to output electrical energy from the target substation.

[0029] Step S104: In the event of a short circuit within the zone, short circuit calculation is performed based on the grid parameters and the second short circuit fault point within the zone to obtain the second short circuit current flowing through the outgoing line. The phasor sum of the second short circuit current is calculated to determine the upper limit of the operating setting of the fast circuit breaker.

[0030] Step S105: Determine the operating settings of the fast circuit breaker based on the upper limit and lower limit of the operating settings.

[0031] Substations are core nodes in a power grid, responsible for voltage transformation, power collection and distribution, power flow control, and fault isolation. A target substation refers to a specific substation requiring short-circuit current flexible suppression upgrades. The target voltage side refers to a specific voltage level, such as 220kV or 110kV. Within a target substation, the target voltage side refers to the substation level requiring short-circuit current mitigation. Topology is the physical basis for short-circuit current calculations and regional division. Power grid parameters are the input conditions for quantitative short-circuit calculations.

[0032] The grid parameters are obtained under the grid's maximum operating mode, i.e., the mode with the highest short-circuit current. If the setpoints calculated based on the grid parameters obtained under the maximum operating mode meet the selectivity requirements, they will also meet them under other operating modes. This ensures that subsequent short-circuit calculations are based on the most stringent boundary conditions, providing sufficient safety margins for the action setpoints and preventing setpoint failure due to changes in operating mode.

[0033] Power grid parameters can be obtained from the power grid operation department. The obtained power grid parameters include equipment parameters of various links such as power generation, transmission, transformation and consumption, as well as electrical parameters and connection relationships of equipment such as generators, transformers, transmission lines and busbars involved in short-circuit current calculation.

[0034] Obtain the topology of the target voltage side, such as double busbar connection, single busbar segmented connection, number of incoming and outgoing lines, and connection method. The topology directly determines the distribution path of short-circuit current and the electrical connection between each outgoing line. Different busbar connection methods will result in different current distribution ratios among the outgoing lines during a fault, thus affecting the phasor sum calculation results. By obtaining an accurate topology, a structural foundation can be provided for subsequent division of the internal and external zones, determination of the positive direction of outgoing lines, and establishment of a short-circuit calculation model, ensuring that the setting method matches the actual engineering scenario.

[0035] This embodiment obtains complete power grid parameters and topology under maximum operating conditions, laying an accurate and reliable data foundation for all subsequent short-circuit calculations, phasor settings, and tuning. It avoids the modeling complexity and computational redundancy caused by excessively large parameter ranges, and eliminates setting deviations due to missing parameters or inadequate consideration of operating conditions. This solves the problem of maloperation or failure to operate caused by inaccurate input data in related technologies, improving the scientific rigor and engineering adaptability of short-circuit current flexible suppression technology tuning.

[0036] The short-circuit current flexible suppression zone is divided into an inner and outer zone based on the topology, which is used to establish selective logic for short-circuit current flexible suppression. The short-circuit current flexible suppression device needs to be able to identify whether the fault occurs inside or outside the zone, and thus adopt different action strategies.

[0037] The short-circuit current flexible suppression zone includes fast circuit breakers because the operating speed of ordinary circuit breakers cannot meet the technical requirements for flexible suppression. The full breaking time of ordinary circuit breakers is typically 40 to 60 milliseconds. By the time an ordinary circuit breaker operates, the short-circuit current has already reached its peak value, and it can only isolate the fault, not suppress the current.

[0038] Fast-acting circuit breakers operate significantly faster than conventional circuit breakers. They can complete the circuit between a portion of the branch and the fault point within the time window after a short-circuit fault occurs and before a conventional circuit breaker completes its tripping, thereby altering the power grid topology and reducing the short-circuit current to within the breaking capacity of conventional circuit breakers. Therefore, fast-acting circuit breakers are included in the suppression zone to perform flexible short-circuit current suppression.

[0039] Flexible short-circuit current suppression refers to a short-circuit current suppression device that, upon detecting a fault current, drives a fast-acting circuit breaker to quickly disconnect the circuit between a portion of the branch and the fault point before the conventional circuit breaker has completed its tripping. This alters the power grid topology, reducing the short-circuit current flowing into the fault point to within the breaking capacity of the conventional circuit breaker. After the fault is cleared, the power grid topology quickly returns to its normal, complete wiring configuration.

[0040] When a fault occurs outside the designated area, although the short-circuit current amplitude is large, this current is essentially through-current to the substation. If the fast-break circuit breaker trips, it will force the fault-free busbars or lines that should be operating normally within the substation to shut down, thereby expanding the scope of the accident and causing a large-scale power outage for users. Therefore, even though the fault current occurring outside the designated area is large, the fast-break circuit breaker must remain stationary to ensure that the power outage is limited to the area within the preset range.

[0041] To prevent the fast circuit breaker from malfunctioning due to potential current flowing through the target voltage side during all external faults, the most severe fault point outside the zone is selected as the calculation benchmark. When a fault occurs at the most severe fault point outside the zone, the total short-circuit current flowing through the outgoing line of the target voltage side reaches its maximum value. Only by using this maximum value as a threshold can it be guaranteed that the fast circuit breaker will not be falsely triggered under any external fault.

[0042] Outgoing lines refer to transmission lines connected to the target voltage side busbar for transmitting power to the next level substation or user. In other words, all outgoing lines are the only channel connecting the busbar within the area to the power grid outside the area.

[0043] Sensitivity analysis can be used to determine the outgoing lines required for setting calculations and real-time data acquisition. The contribution of short-circuit current to each line under different fault locations can be analyzed. That is, when the fault occurs at this station, the short-circuit current level of the selected outgoing line is higher than that of the fault at an adjacent station. This helps to determine the outgoing lines for acquiring current when setting the upper and lower limits of the action setting value.

[0044] Related technologies rely on local nodes for judgment, adjusting settings solely based on the magnitude of short-circuit current at those local nodes. This makes it difficult to accurately distinguish whether a fault occurs within or outside the fault zone, leading to false triggering of fast circuit breakers when faults occur outside the zone due to larger current amplitudes. This embodiment, however, is based on overall boundary conditions. By calculating the phasor sum of all outgoing currents, it directly determines whether a short-circuit fault occurs within the fault zone by utilizing the overall difference in current distribution characteristics between faults within and outside the zone.

[0045] This embodiment uses the minimum phasor sum calculated from the least severe fault point within the zone as the basis for the upper limit of the action setting, and the maximum phasor sum calculated from the most severe fault point outside the zone as the basis for the lower limit of the action setting. This ensures that the phasor sum during a fault within the zone is always greater than the upper limit of the action setting, and the phasor sum during a fault outside the zone is always less than the lower limit of the action setting, thereby achieving selective protection that ensures reliable operation within the zone and reliable non-operation outside the zone.

[0046] Related technologies require pre-calculation of a list of fault locations exceeding the standard through short-circuit calculations, followed by calculation of the action setting value, which is computationally intensive and complex. This embodiment only needs to calculate the setting value using the least severe fault point within the zone and the most severe fault point outside the zone, resulting in less computation and greater convenience. Furthermore, a single setting value can cover both busbar and line faults exceeding the standard, thus making the scope of the short-circuit current flexible suppression effect more clearly defined and more selective, ensuring reliable operation during faults within the zone and reliable non-operation during faults outside the zone.

[0047] When calculating the lower limit of the operating setting, the location with the shortest electrical distance and the largest contribution of short-circuit current from the local substation among all faults outside the zone is selected. When a short circuit occurs at these fault points, the phasor sum of the short-circuit current flowing through the local outgoing lines reaches its maximum value, representing the situation where the fast circuit breaker is most likely to malfunction due to an external fault. By accurately quantifying the actual electrical impact of external faults on the local busbar and fast circuit breakers, it can be ensured that the phasor sum under all external faults is less than the lower limit of the setting, thereby guaranteeing that the fast circuit breaker will not operate reliably.

[0048] A short circuit within the zone is a scenario where a fast-acting circuit breaker should trip. By calculating the total current under the least severe fault within the zone (e.g., the one closest to the circuit breaker, with the highest short-circuit impedance and lowest current), an upper limit of the tripping setting can be determined. This upper limit represents the minimum current flowing through the outgoing lines during a fault within the zone. If the measured current exceeds this upper limit, it indicates that the fault is definitely within the zone and is very serious; the device must trip immediately to suppress the short-circuit current and protect the equipment.

[0049] The upper and lower limits of the operating setting are compared and weighed to select a value that falls between the two and has sufficient margin, which is then written as the final operating setting value for the fast circuit breaker controller. The operating setting value is slightly higher than the lower limit to ensure that it will not be falsely triggered, while being much lower than the upper limit to ensure reliable operation under any fault within the zone. The operating setting value setting method for flexible suppression of grid short-circuit current provided by the embodiments of this invention clearly divides the protection range of the flexible suppression of short-circuit current technology into inside and outside the zone. Based on the phasor of the most severe fault point outside the zone, the lower limit of the operating setting value is obtained, so that when a short circuit occurs outside the zone, the current will necessarily be less than the operating setting value, and the fast circuit breaker will reliably not operate. Based on the phasor of the least severe fault point within the zone, the upper limit of the operating setting value is obtained, so that when a short circuit occurs within the zone, the current flowing through the outgoing line will necessarily be greater than the operating setting value, and the fast circuit breaker will reliably operate.

[0050] By setting the action value within the range defined by the upper and lower limits, a single setting value can simultaneously cover both bus faults and line faults, achieving selective protection that ensures reliable operation within the zone and reliable non-operation outside the zone. This solves the problem in related technologies where flexible suppression of short-circuit current may malfunction when the fault point is located outside the target voltage side of the substation, thus affecting the operation of the power grid.

[0051] As an optional approach, in the event of a short circuit outside the designated area, short circuit calculations are performed based on grid parameters and the first short circuit fault point outside the designated area to obtain the first short circuit current flowing through the outgoing line. The phasor sum of the first short circuit current is calculated to determine the lower limit of the operating setting of the fast circuit breaker. This includes: the first short circuit fault point includes fault points on the busbars of other voltage sides in the target substation besides the target voltage side busbar, and fault points on the busbars connecting adjacent substations to the target substation; the first short circuit current is positively oriented from the target voltage side busbar to the outgoing line; the first phasor sum of the first short circuit current is obtained by calculating and summing the phasors of each first short circuit current; the first coefficient is determined based on the voltage level of the target voltage side and the relay protection setting requirements; and the lower limit of the operating setting is calculated using the formula for calculating the lower limit of the operating setting based on the maximum effective value of the first phasor sum and the first coefficient.

[0052] The fault points outside the zone are limited to the fault points on other voltage-side busbars of the target substation and the connecting busbars of adjacent substations. These locations are the electrical points most likely to provide significant short-circuit currents to this zone from external faults, covering all through-fault scenarios that require transmission through the zone's busbars. The first short-circuit fault point ensures that short-circuit calculations cover all critical external fault types, laying the foundation for subsequent calculations of the most severe through-currents, thus avoiding underestimation of settings and malfunctions due to missed fault points.

[0053] The first short-circuit current takes the direction from the target voltage side bus to the outgoing line as the positive direction, which unifies the phase reference of each outgoing line current, making the subsequent phasor sum calculation physically consistent.

[0054] The first coefficient is a reliability coefficient determined according to the voltage level of the target voltage side and the industry's relay protection setting requirements. For example, for a target voltage side of 220kV, the first coefficient is 1.3. The first coefficient is used to account for uncertainties such as errors in short-circuit current calculations, changes in system operating modes, and inaccurate measurements. By calculating the lower limit of the action setting through the first coefficient, sufficient margin can be reserved for flexible suppression of short-circuit current, ensuring that even under the most unfavorable conditions, the measured phasor sum during external faults will not exceed the set value, thereby reliably preventing false tripping.

[0055] By selecting the maximum effective value of the first phasor sum as the basis for calculation, it is ensured that the lower limit of the final operating setting is higher than the current through which all possible external faults pass. On this basis, a reliability coefficient greater than 1 is multiplied, which is equivalent to forming a double guarantee. Ultimately, it is guaranteed that under any external fault, the measured current will not reach the operating setting, thus completely avoiding the false tripping of the fast circuit breaker.

[0056] This embodiment, based on fault points outside the fault zone and using a unified positive direction specification as a benchmark, precisely determines the lower limit of the action setting by using the maximum value of the effective value of the first phasor sum and the first coefficient. This lower limit can reliably avoid the total short-circuit current flowing through the outgoing line during all faults outside the fault zone, thus solving the problem of potential maloperation of the setting during faults outside the fault zone in related technologies. At the same time, the lower limit of the action setting also provides sufficient room for sensitive operation during faults within the fault zone, comprehensively improving the selectivity, reliability, and adaptability of the short-circuit current flexible suppression technology, ensuring accurate control and stable operation of the power grid under fault conditions.

[0057] As an optional approach, the formula for calculating the lower limit of the action setpoint is as follows: I set_min = k1*I1; where I set_min It represents the lower limit of the action setpoint; k1 represents the first coefficient; I1 represents the maximum effective value of the first phasor sum.

[0058] Take the maximum value I1 among the effective values ​​of the sum of the first phasors at all fault points outside the zone, multiply it by the first coefficient k1, and obtain the lower limit of the action setting I. set_min This transforms theoretical calculations into engineering settings, ensuring that the lower limit of the final operating setting is higher than the through-current of all possible external faults, thus guaranteeing that the fast circuit breaker remains blocked during any external short circuit. Simultaneously, by employing the maximum value of the phasor sum, this setting can avoid the most severe external faults without excessively raising it and affecting the identification of internal faults, achieving a balance between selectivity and sensitivity.

[0059] As an optional approach, in the event of a short circuit within the zone, short circuit calculations are performed based on grid parameters and the second short-circuit fault point within the zone to obtain the second short-circuit current flowing through the outgoing line. The phasor sum of the second short-circuit current is calculated, and the upper limit of the operating setting of the fast circuit breaker is determined. This includes: the second short-circuit fault point includes the fault point on the target voltage side bus and the fault point at the beginning of the outgoing line, wherein the beginning of the outgoing line is a line section within a preset length range along the outgoing line extension direction starting from the target voltage side bus; the second short-circuit current is positive from the bus to the outgoing line; the second phasor sum of the second short-circuit current is obtained by calculating and summing the phasors of each second short-circuit current; a second coefficient is determined based on the voltage level of the target voltage side and the relay protection setting requirements; a third coefficient is determined based on the ratio of the effective value of the bus short-circuit current to the circuit breaker breaking current under the maximum operating mode of the target substation; and the upper limit of the operating setting is calculated based on the minimum value of the second phasor sum, the second coefficient, and the third coefficient using the formula for calculating the upper limit of the operating setting.

[0060] In engineering practice, the preset length range can be taken as 5% to 10% of the total line length, or a fixed absolute length. This area is very close to the busbar in terms of electrical distance. Because the short-circuit current level on the outgoing line is extremely high when a short circuit occurs within the preset length range, it is very close to the current value of a metallic short circuit on the busbar. Therefore, using the outgoing line's starting end as a representative calculation point for faults within the area can cover extreme short-circuit conditions within the area. The phasor sum calculated based on this point can reflect the overall level of the phasor sum during a fault within the area, providing a reliable boundary basis for subsequently setting the upper limit of the action setting value to the minimum value.

[0061] By using the outgoing line's starting end as a representative calculation point for faults within the zone, and selecting the minimum value of the second phasor and effective value among all fault points at the starting end, reliable operation can be ensured even for the least sensitive faults at the starting end. This improves the sensitivity of the action setting selection while guaranteeing operational reliability and ensures sufficient operational margin.

[0062] The second short-circuit current takes the direction from the target voltage side busbar to the outgoing line as the positive direction, unifying the phase reference of each outgoing line current and ensuring physical consistency in subsequent phasor sum calculations. During faults within the zone, since the fault point is located on the zone busbar or at the beginning of the outgoing line, all outgoing line currents flow from the busbar to the fault point, in the same positive direction. Therefore, the phases of each current phasor are essentially consistent. By unifying the positive direction, this in-phase relationship can be accurately reflected in phasor calculations, creating conditions for utilizing the phasor superposition characteristic.

[0063] When a short circuit occurs within the zone, the current from each outgoing line flows towards the fault point in essentially the same direction. By calculating the phasor sum for each fault point within the zone and using the minimum phasor sum across all fault points as the setting basis for the upper limit of the operating setting, it can be ensured that the actual phasor sum is greater than the upper limit when a fault occurs at any location within the zone. This ensures reliable operation of the fast circuit breaker while providing sufficient margin for setting selection.

[0064] Because faults at different locations within the zone can cause differences in the amplitude and phase of the short-circuit current flowing through each outgoing line, the calculated phasor sums will also differ. Therefore, it is necessary to take the minimum effective value of the second phasor sum at all fault points within the zone as the basis for calculation. This is to ensure that the fast circuit breaker can still operate reliably even when the impact on the zone is relatively small.

[0065] The second coefficient is a reliability coefficient determined according to the voltage level of the target voltage side and the industry's relay protection setting requirements. For example, for a target voltage side of 220kV, the second coefficient is usually taken as 1.3 to 1.5. The second coefficient is used to account for uncertainties such as errors in short-circuit current calculations, changes in system operating modes, and inaccurate measurements.

[0066] The third coefficient is the ratio of the effective value of the bus short-circuit current to the circuit breaker breaking current under the maximum operating mode of the target substation. It is used to reflect the relationship between the actual short-circuit current level and the equipment's breaking capacity, ensuring that the operating settings match the actual breaking capacity of the equipment. Introducing the third coefficient allows the upper limit of the operating settings to fully consider the degree to which the short-circuit current exceeds the circuit breaker's breaking capacity, improving the relevance and reliability of the operating settings.

[0067] This embodiment, based on the fault point within the zone and using a unified positive direction specification as a benchmark, precisely determines the upper limit of the operating setting through comprehensive calculation of the minimum value of the second phasor and the effective value, as well as the second and third coefficients. This upper limit ensures that the total short-circuit current flowing through the outgoing line exceeds this setting in all zone faults, thus resolving the issue of potential failure to operate under zone fault conditions in related technologies. Simultaneously, when used in conjunction with the lower limit of the operating setting, it comprehensively improves the selectivity, reliability, and adaptability of the flexible short-circuit current suppression technology, ensuring precise control and stable operation of the power grid under fault conditions.

[0068] As an optional approach, the formula for calculating the upper limit of the action setpoint is as follows: I set_max =I² / (k²*k³); where I set_max I1 represents the upper limit of the action setpoint; I2 represents the minimum value of the second phasor and the effective value; k2 represents the second coefficient, and k3 represents the third coefficient.

[0069] This embodiment uses the minimum value I2 of the sum of the second phasors and effective values ​​at all fault points within the zone as a benchmark, and then divides it by a reliability coefficient k2 and a third coefficient k3, both greater than 1, to obtain the upper limit of the operating setting. This calculation method transforms theoretical calculations into engineering settings, ensuring that the final upper limit of the operating setting is lower than the sum of all possible fault phasors within the zone. This guarantees that the fast circuit breaker can operate reliably during any short circuit within the zone, thus solving the problem in related technologies where the setting may fail to operate during faults within the zone.

[0070] As an optional approach, the short-circuit current flexible suppression zone is divided into an inner and outer zone based on the topology, including: the outgoing lines and the target voltage side busbars are divided into the inner zone based on the topology; other voltage side buses in the target substation besides the target voltage side busbars, as well as other substations outside the target substation, are divided into the outer zone.

[0071] Outgoing lines and the target voltage side busbar are the core areas with the highest risk of excessive short-circuit current. The target voltage side busbar is the central node where short-circuit current converges; once a fault occurs, the short-circuit current flowing through the busbar is the largest. Outgoing lines are the only channel connecting the busbar to the external power grid. When a fault occurs at the beginning of an outgoing line, the short-circuit current level is extremely close to that of a fault on the busbar, requiring the use of fast circuit breakers to disconnect part of the outgoing lines to alter the topology and achieve suppression. Therefore, including outgoing lines and the target voltage side busbar, which are directly related to the effectiveness of short-circuit current suppression, within this area ensures that fast circuit breakers accurately cover all fault scenarios requiring operation.

[0072] In the target substation, the busbars of other voltage levels besides the target voltage side are electrically isolated from the target voltage side by transformers, and the transformer impedance significantly reduces the transmission of short-circuit current.

[0073] Substations outside the target substation and their connected busbars are outside the protection range of the local fast-acting circuit breakers. Their fault currents are through-currents. If these faults are disconnected by the local circuit breakers, not only will the actual fault point not be isolated, but it will also force power outages on fault-free busbars and outgoing lines, artificially expanding the scope of the accident. Therefore, classifying substations outside the target substation and their connected busbars as outside the zone ensures that the fast-acting circuit breakers only operate in the zone during faults, achieving precise selective isolation and avoiding disruption to the power grid's reliability due to cascading tripping.

[0074] This embodiment clarifies the operating region of the fast circuit breaker through precise topology-based partitioning, providing clear boundary conditions for subsequent calculations of phasor sums under faults within and outside the region. This solves the problem of false tripping or failure to trip caused by unclear fault location identification, ensuring that the short-circuit current flexible suppression technology can achieve the selective goals of precise operation under faults within the region and reliable blocking under faults outside the region.

[0075] As an optional approach, the final action setting value is determined based on the upper and lower limits of the action setting value. This includes: simulating potential interference factors in the actual short-circuit current through simulation or dynamic model testing to obtain the actual current carrying range that the short-circuit current flexible suppression device can accurately measure; wherein, the short-circuit current flexible suppression device includes a fast circuit breaker; and determining the action setting value based on the upper and lower limits of the action setting value, combined with the actual current carrying range.

[0076] The actual current carrying range refers to the range of short-circuit current amplitude that the short-circuit current flexible suppression device can accurately measure, reliably judge, and effectively execute in the actual operating environment.

[0077] Because the short-circuit current in the actual power grid is not an ideal sine wave, it may contain complex interference factors such as harmonics, DC components, noise, and measurement errors. These factors can affect the accuracy of the device in measuring the current amplitude and the reliability of its action judgment.

[0078] This embodiment, through simulation or dynamic model testing, introduces interference factors under controlled conditions to systematically test the operational behavior of the short-circuit current flexible suppression device under different current amplitudes and interference levels. This allows for the determination of the minimum current setting that ensures the device's operation and the maximum current setting that ensures it does not operate. These two boundary values ​​jointly define the actual current-carrying range within which the device can reliably operate under real-world conditions, thus transforming the theoretical setting into an engineering-usable setting.

[0079] The final operating setpoint must fall within the range defined by the theoretically calculated lower and upper limits of the operating setpoint to ensure selectivity; simultaneously, it must fall within the actual current-carrying range of the device, i.e., greater than the "maximum current setpoint to ensure no operation" and less than the "minimum current setpoint to ensure operation," to ensure accurate measurement and reliable operation of the device. The operating setpoint is the intersection of these two ranges, and a value that balances safety margin and engineering convenience is selected from the intersection.

[0080] This embodiment combines the theoretically calculated upper and lower limits of the action setting with the actual current carrying range of the short-circuit current flexible suppression device, thus completing the transformation from theoretical values ​​to engineering values. This ensures that the final action setting not only satisfies selectivity but also possesses engineering feasibility, i.e., it accommodates device errors and remains within the measurement range. This solves the problem of actual setting failure caused by neglecting the physical characteristics of the device, guaranteeing the reliability and accuracy of the short-circuit current flexible suppression technology in actual power grids.

[0081] As an optional approach, after determining the operating setpoint of the fast circuit breaker based on the upper and lower limits of the operating setpoint, the method further includes: storing the operating setpoint; collecting the short-circuit current flowing through the outgoing line in real time and calculating the effective value of the phasor sum of the short-circuit current; and controlling the fast circuit breaker to perform flexible suppression of the short-circuit current when the effective value of the phasor sum is greater than the operating setpoint.

[0082] After completing the setting calculations for the action settings, the final determined action settings are stored in the control unit of the short-circuit current flexible suppression device, i.e., the fast circuit breaker controller. This is a crucial step in converting the theoretical calculation results into executable logical instructions for the short-circuit current flexible suppression device, ensuring that the device can make judgments based on preset thresholds during operation. The stored settings are typically fixed in non-volatile memory in digital form to prevent loss of settings due to power outages or restarts, providing a reliable comparison benchmark for subsequent real-time monitoring.

[0083] The short-circuit current flexible suppression device enters real-time monitoring mode, continuously collecting the instantaneous values ​​of the short-circuit current flowing through each outgoing line via sampling devices such as current transformers. Since the operating setting is based on the effective value of the phasor sum of the short-circuit currents, after collecting the current from each outgoing line, the flexible suppression device needs to calculate the phasor of each outgoing line current in real time, taking the direction from the busbar to the outgoing line as positive, summing the phasors, and then calculating the effective value of the phasor sum. The effective value of the phasor sum of each outgoing line current must be highly consistent with the algorithm used in the setting calculation to avoid setting failure due to algorithm differences.

[0084] After obtaining the real-time phasor sum and RMS value, it is compared with the pre-stored action setting value. When the RMS value of the phasor sum is detected to be greater than the action setting value, it can be determined that the current fault characteristics meet the criteria for an in-zone fault, that is, the current amplitude is large enough to exceed the maximum value that an out-of-zone fault may occur. The short-circuit current flexible suppression device immediately issues a tripping command to the operating mechanism of the fast circuit breaker. After receiving the command, after the short-circuit fault occurs, before the conventional circuit breaker completes its tripping, the fast circuit breaker quickly disconnects the circuit between some branches and the fault point, thereby suppressing the short-circuit current within the allowable range by changing the power grid topology, thus realizing the short-circuit current flexible suppression function.

[0085] This embodiment transforms action settings into actual control logic through a complete closed-loop process of storage, acquisition, calculation, comparison, and execution. This process ensures that the fast circuit breaker only operates when the fault criteria within the zone are met, while remaining locked during external faults or normal load fluctuations. This achieves a perfect connection between setting theory and engineering practice, ultimately ensuring that the short-circuit current flexible suppression technology can accurately and quickly play its expected role in actual operation.

[0086] It should be noted that this embodiment also provides an optional implementation method, which will be described in detail below.

[0087] This embodiment uses a 220kV target substation as a specific example, with wiring as follows: Figure 2 As shown, it consists of two sections of double busbars, upper and lower, which are interconnected by bus tie 1 and bus tie 2. Bus branch 1 and bus branch 2 are the fast circuit breaker installation positions specified in this embodiment, which are used to quickly interrupt the circuit in case of a fault in the zone to suppress the short circuit current.

[0088] The upper busbar connects to seven outgoing lines (L1 to L7) and main transformers T1 and T3, while the lower busbar connects to six outgoing lines (L8 to L13) and main transformer T2. All outgoing lines are equipped with conventional circuit breakers. In this embodiment, L1 and L5 are representative outgoing lines of the upper busbar, L12 is a representative outgoing line of the lower busbar, and T2 is the branch of the main transformer on the lower busbar, covering the core electrical branches on both sides of the double busbars to ensure the reliability of fault diagnosis and setting.

[0089] Short-circuit current calculations show that the short-circuit current level on the target voltage side under maximum operating conditions is 51.04 kA, exceeding the circuit breaker's breaking capacity. Flexible short-circuit current suppression measures are implemented at the target substation. Fast-acting circuit breakers are installed at the two target voltage side busbars (Bus Branch 1 and Bus Branch 2), and the currents of the four outgoing lines L1, L5, L12, and T2 are collected as the basis for fault diagnosis.

[0090] Simultaneously, short-circuit current calculations were performed on short-circuit faults within the zone. The results show that when a fault occurs on the target voltage side busbar, the phasor sum of the second short-circuit currents collected from the outgoing lines is 25.54 kA; when a fault occurs at the beginning of the outgoing lines on the target voltage side, the minimum phasor sum of the second short-circuit currents collected from the outgoing lines is 25.50 kA. Therefore, the minimum effective value I2 of the second phasor sum at all fault points within the zone is taken as 25.50 kA.

[0091] Short-circuit current calculations for faults outside the fault zone reveal that when a fault occurs on the busbar of an adjacent substation, the maximum phasor sum of the first short-circuit current collected from the outgoing lines is 3.35 kA. Therefore, the maximum effective value I1 of the first phasor sum at all fault points outside the fault zone is taken as 3.35 kA.

[0092] According to the setting method of the present invention, the first coefficient k1 is 1.5, and the lower limit of the action setting is 3.35×1.5=5.02kA; the second coefficient k2 is 1.05, and the third coefficient k3 is the ratio of the maximum short-circuit current level to the circuit breaker breaking current, 51.04 / 50, and the upper limit of the action setting is 25.50 / (1.05×51.04 / 50)=23.8kA.

[0093] Therefore, the final operating setting can be determined within the range defined by the lower limit of 5.02kA and the upper limit of 23.8kA. Within this setting range, the selective objective of reliable operation of the fast circuit breaker in the event of a short circuit within the zone and reliable cessation of operation in the event of a short circuit outside the zone can be achieved.

[0094] Embodiments of the present invention also provide a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform a method according to an embodiment of the present invention.

[0095] Embodiments of the present invention also provide a computer program product, including a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform the method of an embodiment of the present invention.

[0096] An embodiment of the present invention also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, which, when executed by the at least one processor, causes the electronic device to perform the method of the embodiment of the present invention.

[0097] refer to Figure 3 The present invention will now describe a structural block diagram of an electronic device that can serve as an embodiment of the present invention, serving as an example of a hardware device applicable to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0098] like Figure 3 As shown, the electronic device includes a computing unit 301, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 302 or a computer program loaded from a storage unit 308 into a random access memory (RAM) 303. The RAM 303 may also store various programs and data required for the operation of the electronic device. The computing unit 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0099] Multiple components in the electronic device are connected to I / O interface 305, including: input unit 306, output unit 307, storage unit 308, and communication unit 309. Input unit 306 can be any type of device capable of inputting information into the electronic device. Input unit 306 can receive input digital or character information and generate key signal inputs related to user settings and / or function control of the electronic device. Output unit 307 can be any type of device capable of presenting information and may include, but is not limited to, a display, speaker, video / audio output terminal, vibrator, and / or printer. Storage unit 308 may include, but is not limited to, disks and optical discs. Communication unit 309 allows the electronic device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks, and may include, but is not limited to, modems, network cards, infrared communication devices, and / or wireless communication transceivers, such as Bluetooth devices, WiFi devices, WiMax devices, cellular communication devices, and / or the like.

[0100] The computing unit 301 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, CPUs, graphics processing units (GPUs), various special-purpose artificial intelligence (AI) computing units, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any suitable processors, controllers, microcontrollers, etc. The computing unit 301 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present invention can be implemented as computer programs tangibly contained in a machine-readable medium, such as storage unit 308. In some embodiments, part or all of the computer program can be loaded and / or installed on an electronic device via ROM 302 and / or communication unit 309. In some embodiments, the computing unit 301 can be configured to perform the methods described above by any other suitable means (e.g., by means of firmware).

[0101] Computer programs for implementing the methods of embodiments of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0102] In the context of embodiments of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, or infrared systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0103] It should be noted that the term "comprising" and its variations used in the embodiments of this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality" mentioned in the embodiments of this invention are illustrative and not restrictive, and those skilled in the art should understand that unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0104] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of this invention are subject to strict compliance with relevant laws, regulations, and regulatory requirements in their collection, storage, use, processing, transmission, provision, and disclosure, and adhere to the principles of legality, legitimacy, necessity, and good faith. The acquisition of relevant information and data is premised on the user's explicit consent or other legitimate reasons, and a clear and convenient authorization management approach is provided to the user, allowing the user to independently choose to consent, withdraw consent, or refuse to provide relevant information. For functions that rely on user information, if the user does not authorize or withdraws authorization, the corresponding technical function cannot be implemented, and the technical solution of this invention is not applicable in this scenario.

[0105] The steps described in the method embodiments provided by the present invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0106] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0107] The above-described embodiments 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 protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive 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 the present invention should be determined by the appended claims.

Claims

1. A method for setting the operating setting value for flexible suppression of short-circuit current in a power grid, characterized in that, include: The grid parameters and the topology of the target voltage side in the target substation are obtained. In the event of a short circuit, the target voltage side of the target substation uses the corresponding action setting to flexibly suppress the short circuit current. The short-circuit current flexible suppression zone is divided into an inner zone and an outer zone according to the topology. The short-circuit current flexible suppression zone includes a fast circuit breaker. The short-circuit current is flexibly suppressed by controlling the operation of the fast circuit breaker. In the event of a short circuit outside the specified area, a short circuit calculation is performed based on the grid parameters and the first short circuit fault point outside the specified area to obtain the first short circuit current flowing through the outgoing line. The phasor sum of the first short circuit current is calculated to determine the lower limit of the operating setting of the fast circuit breaker. The outgoing line is a transmission line on the target voltage side bus used to output electrical energy from the target substation. In the event of a short circuit in the area, a short circuit calculation is performed based on the power grid parameters and the second short circuit fault point in the area to obtain the second short circuit current flowing through the outgoing line. The phasor sum of the second short circuit current is calculated to determine the upper limit of the operating setting of the fast circuit breaker. The operating settings of the fast circuit breaker are determined based on the upper limit and the lower limit of the operating settings.

2. The method for setting the action setting value for flexible suppression of short-circuit current in power grids according to claim 1, characterized in that, In the event of a short circuit outside the specified area, short circuit calculations are performed based on the grid parameters and the first short circuit fault point outside the specified area to obtain the first short circuit current flowing through the outgoing line. The phasor sum of the first short circuit current is calculated, and the lower limit of the operating setting of the fast circuit breaker is determined, including: The first short-circuit fault point includes fault points on other voltage-side buses in the target substation besides the target voltage-side bus, and fault points on the bus connecting the adjacent substation to the target substation; The first short-circuit current is positively oriented with the target voltage side busbar pointing towards the outgoing line; The first phasor sum of the first short-circuit currents is obtained by calculating and summing the phasors of each of the first short-circuit currents. Based on the voltage level of the target voltage side, the first coefficient is determined according to the relay protection setting requirements; Based on the maximum effective value of the first phasor and the first coefficient, the lower limit of the action setpoint is calculated using the action setpoint lower limit calculation formula.

3. The method for setting the action setting value for flexible suppression of short-circuit current in power grids according to claim 2, characterized in that, The formula for calculating the lower limit of the action setpoint is as follows: I set_min = k1*I1; Among them, I set_min It represents the lower limit of the action setpoint; k1 represents the first coefficient; I1 represents the maximum effective value of the first phasor sum.

4. The method for setting the action setting value for flexible suppression of power grid short-circuit current according to claim 1, characterized in that, In the event of a short circuit within the zone, short circuit calculations are performed based on the grid parameters and the second short circuit fault point within the zone to obtain the second short circuit current flowing through the outgoing line. The phasor sum of the second short circuit current is calculated, and the upper limit of the operating setting of the fast circuit breaker is determined, including: The second short-circuit fault point includes a fault point on the target voltage side bus and a fault point at the beginning of the outgoing line, wherein the beginning of the outgoing line is a line section within a preset length range along the outgoing line extension direction starting from the target voltage side bus. The second short-circuit current is in the positive direction from the busbar to the outgoing line; The second phasor sum of the second short-circuit currents is obtained by calculating and summing the phasors of each of the second short-circuit currents. Based on the voltage level of the target voltage side, the second coefficient is determined according to the relay protection setting requirements; The third coefficient is determined based on the ratio of the effective value of the bus short-circuit current to the circuit breaker breaking current under the maximum operating mode of the target substation. The upper limit of the action setpoint is calculated using the action setpoint upper limit calculation formula based on the minimum value of the second phasor and the effective value, the second coefficient and the third coefficient.

5. The method for setting the action setting value for flexible suppression of power grid short-circuit current according to claim 4, characterized in that, The formula for calculating the upper limit of the action setpoint is as follows: I set_max =I2 / (k2*k3); Among them, I set_max I1 represents the upper limit of the action setpoint; I2 represents the minimum value of the second phasor and the effective value; k2 represents the second coefficient, and k3 represents the third coefficient.

6. The method for setting the action setting value for flexible suppression of short-circuit current in power grids according to claim 1, characterized in that, The short-circuit current flexible suppression region is divided into an inner and outer region based on the aforementioned topology, including: Based on the topology, the outgoing line and the target voltage side bus are divided into zones; Other voltage-side buses in the target substation besides the target voltage-side bus, as well as other substations outside the target substation, are classified as outside the zone.

7. The method for setting the action setting value for flexible suppression of short-circuit current in power grids according to claim 1, characterized in that, Determining the operating setting of the fast circuit breaker based on the upper limit and the lower limit of the operating setting also includes: Through simulation or dynamic model testing, the interference factors that may occur in the actual short-circuit current are simulated to obtain the actual current carrying range that the short-circuit current flexible suppression device can accurately measure; wherein, the short-circuit current flexible suppression device includes a fast circuit breaker. The action setpoint is determined based on the upper limit and lower limit of the action setpoint, combined with the actual current flow range.

8. The method for setting the action setting value for flexible suppression of short-circuit current in power grids according to claim 1, characterized in that, After determining the operating setting value of the fast circuit breaker based on the upper limit and the lower limit of the operating setting value, the method further includes: Store the action settings; The short-circuit current flowing through the outgoing line is collected in real time, and the effective value of the phasor sum of the short-circuit current is calculated. When the effective value of the sum of the phasors is greater than the setpoint, the fast circuit breaker is controlled to perform flexible suppression of short-circuit current.

9. An electronic device, comprising: A processor and a memory storing a program, characterized in that the program includes instructions that, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 8.

10. A non-transitory machine-readable medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method according to any one of claims 1 to 8.

11. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the method of any one of claims 1 to 8.

Images