Network-configuration-type energy storage control method and system considering short-circuit current constraint and storage medium

Abstract

This application provides a grid-based energy storage control method, system, and storage medium that considers short-circuit current constraints. Upon receiving a fault signal from a critical power grid line, based on the target short-circuit current calculation, it is determined whether switching the energy storage to grid-based control mode before the faulted line is disconnected would cause the short-circuit current at the grid node to exceed the limit. If not, the system switches from grid-following control to a preparatory control mode, and then immediately switches back to grid-based control mode. If yes, it switches from grid-following control to a preparatory control mode, but does not immediately switch back to grid-based control mode. Upon receiving a faulted line disconnection signal, based on the target short-circuit current calculation after the line disconnection, it is determined whether switching the energy storage to grid-based control mode would cause the short-circuit current at the grid node to exceed the limit. If not, it switches from preparatory control mode to grid-based control mode. If yes, it reverts to grid-following control mode. This effectively balances short-circuit current constraints and reactive power voltage support requirements, improving the system's voltage stability.

Description

Technical Field

[0001] This invention relates to the field of power system grid-based control technology, and in particular to a grid-based energy storage control method, system, and storage medium that takes into account short-circuit current constraints. Background Technology

[0002] Grid-based control technology is one of the effective measures to address the problems of insufficient inertia and weakened grid strength in high-proportion renewable energy power systems. However, when applied to power grids in developed regions and around major load centers, grid-based control, especially voltage-supported grid-based control, faces the following technical challenges: On the one hand, the short-circuit current level of the main power grid in developed regions is already close to the critical value of the circuit breaker's breaking capacity. Voltage-supported grid-connected equipment, exhibiting voltage source characteristics, will provide additional large short-circuit currents during faults, easily leading to short-circuit current exceeding limits at grid connection points or critical nodes, threatening the safety of grid equipment. On the other hand, with the increasing penetration rate of new energy sources and the increase in transmission channel load, even in a strong grid environment, when severe faults such as N-2 or Nm (m>2) occur in critical transmission channels, the system still faces the risk of voltage collapse, urgently requiring grid-connected equipment to provide rapid reactive voltage support. Therefore, how to provide necessary voltage support without causing short-circuit current exceeding limits is a key challenge for current grid-connected energy storage applications.

[0003] To address the aforementioned contradictions, existing technologies propose a grid-connected / grid-connected switching technique for grid-connected control elements. This involves real-time monitoring of the grid strength at the connection point, switching to grid-connected mode when the grid strength is weak, and maintaining grid-connected mode when the strength is strong. However, this method has significant limitations: First, the criteria are ambiguous. Existing grid strength indicators such as the short-circuit ratio can only make qualitative judgments and cannot directly reflect the quantitative constraint of whether the short-circuit current value at the grid node exceeds the limit. Second, there are limitations in detection. Existing detection methods are mostly based on local detection at the output side of the grid-connected element. During fault transients, the accuracy of local detection is easily affected, which may lead to false switching or failure to operate, thereby causing short-circuit current exceeding the limit or voltage instability accidents. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a grid-based energy storage control method, system and storage medium that takes into account short-circuit current constraints. For grids with high short-circuit current levels, it can effectively balance short-circuit current constraints and reactive voltage support requirements under severe faults, thereby improving the voltage stability of the system.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A grid-based energy storage control method considering short-circuit current constraints includes: After receiving a fault signal from a critical power grid line, the mode switching signal module determines, based on the first target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching from grid-type energy storage to grid-type control mode before the faulted line is disconnected will cause the short-circuit current of the power grid node to exceed the limit. If not, a first switching signal is sent to the grid-type energy storage. The first switching signal is to switch the energy storage control mode to the preparatory control mode and then immediately switch to the grid-type control mode. If yes, a second switching signal is sent to the grid-type energy storage. The second switching signal is to switch the energy storage control mode to the preparatory control mode but not switch to the grid-type control mode for the time being. After receiving the fault line disconnection signal, the mode switching signal module determines, based on the second target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching the grid-type energy storage to the grid-type control mode after the fault line disconnection will cause the short-circuit current of the grid node to exceed the limit. If not, a third switching signal is sent to the grid-type energy storage, which is to switch the energy storage control mode from the preparatory control mode to the grid-type control mode. If yes, a fourth switching signal is sent to the grid-type energy storage, which is to restore the energy storage control mode to the grid-type control mode. The grid-type energy storage adopts a grid-following control mode under normal operation.

[0006] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: A grid-based energy storage control system considering short-circuit current constraints includes a mode switching signal module, a short-circuit current calculation module, a grid critical channel fault monitoring module, a communication module, and grid-based energy storage. The mode switching signal module includes a first memory, a first processor, and a first computer program stored in the first memory and executable on the first processor. The short-circuit current calculation module includes a second memory, a second processor, and a second computer program stored in the second memory and executable on the second processor. The grid critical channel fault monitoring module includes a third memory, a third processor, and a third computer program stored in the third memory and executable on the third processor. The communication module includes a fourth memory, a fourth processor, and a fourth computer program stored in the fourth memory and executable on the fourth processor. The grid-based energy storage includes a fifth memory, a fifth processor, and a fifth computer program stored in the fifth memory and executable on the fifth processor. When the processor executes the computer program, it implements the steps of the corresponding modules in the aforementioned grid-based energy storage control method considering short-circuit current constraints.

[0007] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described grid-type energy storage control method considering short-circuit current constraints.

[0008] The beneficial effects of this invention are as follows: After receiving a signal indicating a fault has occurred on a critical power grid line, based on the target short-circuit current calculation, it is determined whether switching the energy storage to a grid-based control mode before the faulted line is disconnected would cause the short-circuit current at the grid node to exceed the limit. If not, the energy storage control mode is switched from grid-following control to a preparatory control mode, and then immediately switched to a grid-based control mode. If yes, the energy storage control mode is switched from grid-following control to a preparatory control mode, but not switched to a grid-based control mode yet. Subsequently, after receiving a signal indicating the faulted line has been disconnected, based on the target short-circuit current calculation after the line disconnection, it is determined whether switching the energy storage to a grid-based control mode would cause the short-circuit current at the grid node to exceed the limit. If not, Switching the energy storage control mode from the preparatory control mode to the grid-based control mode, and then reverting to grid-following control mode if the latter is selected, distinguishes it from the traditional qualitative judgment method. This quantitative decision-making based on fault status and short-circuit current margin improves the reliability of the switching criteria between grid-following and grid-based modes. This allows grid-based energy storage to achieve reasonable switching between grid-following and grid-based control modes under the premise that the short-circuit current does not exceed the limit. This ensures that grid-based energy storage provides reactive voltage support under the safety premise of strictly meeting the short-circuit current limit of the grid nodes. Thus, for grids with high short-circuit current levels, it effectively balances the short-circuit current constraints and the reactive voltage support requirements under severe faults, thereby improving the voltage stability of the system. Attached Figure Description

[0009] Figure 1 This is a flowchart of a grid-type energy storage control method considering short-circuit current constraints according to an embodiment of the present invention; Figure 2 This is a flowchart of the control mode switching in a grid-type energy storage control method considering short-circuit current constraints according to an embodiment of the present invention. Figure 3 This is a block diagram of the energy storage converter following / network mode switching control in a grid-type energy storage control method considering short-circuit current constraints according to an embodiment of the present invention. Figure 4 This is a schematic diagram of a grid-type energy storage control system that considers short-circuit current constraints according to an embodiment of the present invention. Detailed Implementation

[0010] Definitions:

[0011] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0012] In existing technologies, real-time detection of grid strength at the grid connection point enables switching of grid construction mode under weak grid conditions and maintaining grid-following mode under strong grid conditions. However, there are significant limitations: First, the criteria are ambiguous. Grid strength indicators such as short-circuit ratio can only be qualitatively judged and cannot directly reflect the quantitative constraints of whether the short-circuit current at the grid node exceeds the limit. Second, the detection reliability is insufficient. Existing methods mostly rely on local measurements at the output side of grid-type equipment. Under fault transients, they are easily affected by disturbances, which can easily lead to false switching or failure to operate, thereby causing problems such as short-circuit current exceeding the limit and voltage instability.

[0013] To at least address the aforementioned problems, the technical solution adopted in this invention is as follows: Upon receiving a signal indicating a fault has occurred on a critical power grid line, based on the target short-circuit current calculation, it is determined whether switching the energy storage to a grid-based control mode before the faulty line is disconnected would cause the short-circuit current at the power grid node to exceed the limit. If not, the energy storage control mode is switched from grid-following control to a preparatory control mode, and then immediately switched to grid-based control mode. If yes, the energy storage control mode is switched from grid-following control to a preparatory control mode, but not switched to grid-based control mode yet. Subsequently, upon receiving a signal indicating the faulty line has been disconnected, based on the target short-circuit current calculation after the line disconnection, it is determined whether switching the energy storage to a grid-based control mode would cause the short-circuit current at the power grid node to exceed the limit. If not, the energy storage control mode is switched from a preparatory control mode to grid-based control mode. If yes, the energy storage control mode reverts to grid-following control. In this way, the reliability of the switching criteria between grid and network modes can be improved, ensuring that grid-connected energy storage provides reactive voltage support under the safety premise of strictly meeting the short-circuit current limit of the grid node. Thus, for grids with high short-circuit current levels, it can effectively take into account both short-circuit current constraints and reactive voltage support requirements under severe faults, thereby improving the voltage stability of the system.

[0014] The following details a grid-based energy storage control method considering short-circuit current constraints, applicable to grid-based energy storage control mode switching scenarios. Please refer to [link / reference]. Figure 1 The method 100 includes steps 101 to 102: Step 101: After receiving the fault signal of the critical line of the power grid, the mode switching signal module determines, based on the first target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching the grid-type energy storage to the grid-type control mode before the fault line is disconnected will cause the short-circuit current of the power grid node to exceed the limit. If not, a first switching signal is sent to the grid-type energy storage. The first switching signal is: switch the energy storage control mode to the preparatory control mode, and then immediately switch to the grid-type control mode. If yes, a second switching signal is sent to the grid-type energy storage. The second switching signal is: switch the energy storage control mode to the preparatory control mode, but do not switch to the grid-type control mode for the time being.

[0015] Among them, determining whether the switching from grid-type energy storage to grid-type control mode before the fault line is disconnected, based on the first target short-circuit current calculation result sent by the short-circuit current calculation module, causes the short-circuit current of the grid node to exceed the limit includes: Before determining whether a faulty line has been disconnected, if the grid-type energy storage system switches to grid-type control mode, is there a target short-circuit current calculation result sent by the short-circuit current calculation module that is greater than or equal to the node short-circuit current upper limit? I max .

[0016] like Figure 2 As shown, specifically, before the faulty line is disconnected, if the grid-type energy storage switches to the grid-type control mode, and the target short-circuit current calculation result sent by the short-circuit current calculation module is greater than or equal to the node short-circuit current upper limit, then... I max This indicates that switching the energy storage to grid-based control will not cause short-circuit current exceeding the limit. In this case, after the energy storage completes synchronization through the switching preparation control, it immediately switches from the grid-following control mode to the grid-based control mode. Conversely, this indicates that there is a risk of node short-circuit current exceeding the limit during the switch, and the energy storage maintains grid-following operation and switches to the switching preparation control (corresponding to...). Figure 2 The command "Keep running with the network and switch to standby control" is executed, and the fault is cleared.

[0017] Step 102: After receiving the fault line disconnection signal, the mode switching signal module determines, based on the second target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching the grid-type energy storage to the grid-type control mode after the fault line disconnection causes the short-circuit current of the grid node to exceed the limit. If not, a third switching signal is sent to the grid-type energy storage. The third switching signal is to switch the energy storage control mode from the preparatory control mode to the grid-type control mode. If yes, a fourth switching signal is sent to the grid-type energy storage. The fourth switching signal is to restore the energy storage control mode to the grid-type control mode.

[0018] The grid-type energy storage adopts a grid-following control mode under normal operation.

[0019] Among them, determining whether the switching of grid-type energy storage to grid-type control mode after the fault line is disconnected, based on the second target short-circuit current calculation result sent by the short-circuit current calculation module, causes the short-circuit current of the grid node to exceed the limit includes: After the faulty line is disconnected, if the grid-type energy storage switches to grid-type control mode, is the target short-circuit current calculation result sent by the short-circuit current calculation module greater than or equal to the node short-circuit current upper limit? I max .

[0020] like Figure 2As shown, specifically, after the faulty line is disconnected, if the grid-type energy storage switches to the grid-type control mode, there is no short-circuit current calculation result sent by the short-circuit current calculation module that is greater than or equal to the node short-circuit current upper limit. I max This indicates that after the fault is cleared, switching the energy storage to grid-type control will not cause the short-circuit current to exceed the limit. At this time, the grid-type energy storage can be switched from the grid-following control mode to the grid-type control mode to support voltage recovery. Conversely, this indicates that switching to the grid-type control mode will still cause the short-circuit current of some nodes to exceed the limit. Therefore, the grid-type energy storage will maintain the grid-following control mode throughout the process and will not be switched.

[0021] The grid-type energy storage system has the capability to provide voltage-supported grid-type control and also has the function of switching between grid-based and grid-based control, such as... Figure 3 As shown, the grid-connected and grid-connected control share a common inner current loop. After receiving the switching signal sent by the mode switching signal module, the grid-connected and grid-connected modes are switched through the outer loop control and phase output. The red box shows the control block diagram of the pre-switching control mode. Its purpose is to achieve pre-synchronization of the grid-connected control and the grid-connected control in phase and voltage amplitude when the energy storage converter mode switches from grid-connected to grid-connected, so as to reduce the current and power surges during the switching process. The pre-switching control mode is specifically as follows: ; In the formula, This represents the amount of phase compensation required for network pre-synchronization. This indicates the amount of voltage compensation required for pre-synchronization of the network. , , , All represent proportional-integral (PI) controller parameters. This indicates that the phase-locked loop follows the phase of the power grid. Indicates the output phase of the network. This indicates the actual voltage value at the grid connection point. This indicates the output voltage of the network.

[0022] Figure 3 middle, Indicates the phase with the output of the grid. , These represent active power output and reactive power output, respectively. , These represent the active power setpoint and the reactive power setpoint, respectively. This indicates the grid voltage.

[0023] As described above, when determining whether switching from grid-based energy storage to grid-based control mode causes the short-circuit current of the grid node to exceed the limit, based on the current grid state, it is determined whether the target short-circuit current calculation result sent by the short-circuit current calculation module is greater than or equal to the node short-circuit current limit after the grid-based energy storage switches to grid-based control mode. This is faster and more accurate, and can maximize the grid support capability of energy storage while ensuring that the grid short-circuit current does not exceed the limit.

[0024] In one embodiment of the present invention, it further includes: During normal operation of the power grid, the short-circuit current calculation module pre-establishes a set of short-circuit current calculation results for each node of the power grid under various typical operating modes based on the current power grid structure and using offline calculation.

[0025] As described above, the short-circuit current calculation result set of each node of the power grid under various typical operating modes is established offline in advance to improve the efficiency of subsequent mode switching judgment.

[0026] Please refer to Figure 2 In one embodiment of the present invention, it further includes: After a fault occurs on a critical power grid line and before the faulty line is disconnected, the critical power grid channel fault monitoring module sends the fault occurrence signal to the mode switching signal module and the short-circuit current calculation module through the communication module when it detects the occurrence of a critical fault. The short-circuit current calculation module obtains the current operating mode of the power grid and matches the current operating mode of the power grid with the short-circuit current calculation result set of each node of the power grid under the various typical operating modes to obtain the short-circuit current calculation result of each node of the power grid under the current operating mode of the power grid. The current operating mode of the power grid is based on the fact that the grid-type energy storage adopts the grid-type control mode as the calculation premise. The short-circuit current calculation module, based on the short-circuit current calculation results of each node of the power grid under the current operating mode of the power grid, selects the short-circuit current calculation results of the power grid nodes with high short-circuit current levels and risks of exceeding limits, as the first target short-circuit current calculation results. The power grid nodes with high short-circuit current levels and risks of exceeding limits are the power grid nodes whose short-circuit current values ​​reach a preset percentage of their upper limit. The short-circuit current calculation module sends the calculation result of the first target short-circuit current to the mode switching signal module.

[0027] In one alternative implementation, the preset percentage is 90%.

[0028] In one alternative implementation, the grid node with a high short-circuit current level and the risk of exceeding the limit can also be determined based on the capacity of the grid-type energy storage in the specific grid and the magnitude of the short-circuit current it provides.

[0029] For example, let For a set of power grid nodes with high short-circuit current levels and a risk of exceeding limits, for each typical operating mode, the following exists: i b,f0,gfm For nodes b The short-circuit current of the energy storage system operating in grid-type control mode before the critical fault line is cleared.

[0030] As described above, after a critical fault occurs, the short-circuit current calculation results of each power grid node that is closest to the current operating mode are matched, and then the short-circuit current calculation results of the power grid nodes with high short-circuit current levels and risks of exceeding limits are selected as the target short-circuit current calculation results. Subsequently, only these calculation results need to be used as the criterion, which improves the judgment efficiency.

[0031] Please refer to Figure 2 In one embodiment of the present invention, it further includes: After a fault occurs on a critical power grid line and the faulty line is disconnected, the critical power grid channel fault monitoring module, upon detecting the disconnection of the faulty line, sends the fault disconnection signal to the mode switching signal module and the short-circuit current calculation module via the communication module. The short-circuit current calculation module matches the short-circuit current calculation result set of each node of the power grid under the various typical operating modes with the power grid operation mode after the fault line is disconnected, and obtains the short-circuit current calculation result of each node of the power grid after the fault line is disconnected. The power grid operation mode after the fault line is disconnected is based on the calculation premise that the grid-type energy storage adopts the grid-type control mode. The short-circuit current calculation module, based on the short-circuit current calculation results of each node in the power grid after the fault line is disconnected, selects the short-circuit current calculation results of power grid nodes with high short-circuit current levels and risks of exceeding limits, as the second target short-circuit current calculation results. The power grid nodes with high short-circuit current levels and risks of exceeding limits are power grid nodes whose short-circuit current values ​​reach a preset percentage of their upper limit. The short-circuit current calculation module sends the calculation result of the second target short-circuit current to the mode switching signal module.

[0032] For example, let For a set of power grid nodes with high short-circuit current levels and a risk of exceeding limits, for each typical operating mode, the following exists: i b,f1,gfm For nodes b The short-circuit current when the energy storage operates in grid-type mode after the critical fault line is disconnected.

[0033] As described above, after the critical fault is cleared, the short-circuit current calculation results of each power grid node that is closest to the current operating mode are matched, and then the short-circuit current calculation results of the power grid nodes with high short-circuit current levels and risk of exceeding limits are selected as the target short-circuit current calculation results to participate in the subsequent switching of the grid-type control mode, thereby improving the judgment efficiency.

[0034] The critical line fault is a three-phase permanent N-2 or Nm fault in an important transmission channel of the power grid, where m>2, and the fault may cause voltage instability risks.

[0035] Please refer to Figure 4 The present invention also provides a grid-based energy storage control system 200 considering short-circuit current constraints, including a mode switching signal module 201, a short-circuit current calculation module 202, a grid critical channel fault monitoring module 203, a communication module 204, and a grid-based energy storage 205. The mode switching signal module 201 includes a first memory, a first processor, and a first computer program stored in the first memory and executable on the first processor. The short-circuit current calculation module 202 includes a second memory, a second processor, and a second computer program stored in the second memory and executable on the second processor. The grid critical channel fault monitoring module 203 includes a third memory, a third processor, and a third computer program stored in the third memory and executable on the third processor. The communication module 204 includes a fourth memory, a fourth processor, and a fourth computer program stored in the fourth memory and executable on the fourth processor. The grid-based energy storage 205 includes a fifth memory, a fifth processor, and a fifth computer program stored in the fifth memory and executable on the fifth processor. When the processor executes the computer program, it implements the steps of the corresponding modules in the above-described grid-based energy storage control method considering short-circuit current constraints.

[0036] The fault monitoring module 203 for critical power grid channels is configured in transmission channels that have a significant impact on the voltage stability of the main power grid. The grid-type energy storage 205 includes an energy storage converter.

[0037] In one optional implementation, the grid critical channel fault monitoring module 203 and the grid-type energy storage 205 can be one or more. If multiple grid-type energy storage and multiple grid critical channel fault monitoring modules are included, when a monitored critical fault occurs in any transmission channel, a fault occurrence signal and a fault clearing signal are sent to each grid-type energy storage.

[0038] According to another aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the various steps of the above-described grid-type energy storage control method considering short-circuit current constraints.

[0039] In summary, the grid-based energy storage control method, system, and storage medium of this invention, which considers short-circuit current constraints, upon receiving a fault signal from a critical power grid line, determines, based on the target short-circuit current calculation, whether switching the energy storage to grid-based control mode before the faulted line is disconnected would cause the short-circuit current at the power grid node to exceed the limit. If not, the energy storage control mode is switched from grid-following control to a preparatory control mode, and then immediately switched to grid-based control mode. If yes, the energy storage control mode is switched from grid-following control to a preparatory control mode, but not immediately switched to grid-based control mode. Subsequently, upon receiving a faulted line disconnection signal, based on the target short-circuit current calculation after the line disconnection, it determines whether switching the energy storage to grid-based control mode would cause the short-circuit current at the power grid node to exceed the limit. If not, the energy storage control mode is switched from the preparatory control mode to grid-based control mode. If yes, the energy storage control mode reverts to grid-following control. This approach, distinct from traditional qualitative judgment methods, utilizes quantitative decision-making based on fault conditions and short-circuit current margins. It improves the reliability of the criteria for switching between grid-connected and grid-connected modes, enabling grid-connected energy storage to rationally switch between grid-connected and grid-connected control modes without exceeding short-circuit current limits. This ensures that grid-connected energy storage provides reactive power and voltage support while strictly adhering to the safety requirement of grid node short-circuit current limits. For grids with high short-circuit current levels, it effectively balances short-circuit current constraints with reactive power and voltage support requirements under severe faults, improving system voltage stability. Furthermore, after a critical fault occurs / is cleared, the short-circuit current calculation results of each grid node closest to the current operating mode are matched. Then, the short-circuit current calculation results of grid nodes with high short-circuit current levels and potential for exceeding limits are selected as target short-circuit current calculation results. Subsequent decisions only require using these calculation results as criteria, improving judgment efficiency.

[0040] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A grid-type energy storage control method considering short-circuit current constraints, characterized in that, include: After receiving a fault signal from a critical power grid line, the mode switching signal module determines, based on the first target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching from grid-type energy storage to grid-type control mode before the faulted line is disconnected will cause the short-circuit current of the power grid node to exceed the limit. If not, a first switching signal is sent to the grid-type energy storage. The first switching signal is to switch the energy storage control mode to the preparatory control mode and then immediately switch to the grid-type control mode. If yes, a second switching signal is sent to the grid-type energy storage. The second switching signal is to switch the energy storage control mode to the preparatory control mode but not switch to the grid-type control mode for the time being. After receiving the fault line disconnection signal, the mode switching signal module determines, based on the second target short-circuit current calculation result sent by the short-circuit current calculation module, whether switching the grid-type energy storage to the grid-type control mode after the fault line disconnection will cause the short-circuit current of the grid node to exceed the limit. If not, a third switching signal is sent to the grid-type energy storage, which is to switch the energy storage control mode from the preparatory control mode to the grid-type control mode. If yes, a fourth switching signal is sent to the grid-type energy storage, which is to restore the energy storage control mode to the grid-type control mode. The grid-type energy storage adopts a grid-following control mode under normal operation.

2. The method of claim 1, wherein, Also includes: During normal operation of the power grid, the short-circuit current calculation module pre-establishes a set of short-circuit current calculation results for each node of the power grid under various typical operating modes based on the current power grid structure and using offline calculation.

3. The method of claim 2, wherein, Also includes: After a fault occurs on a critical power grid line and before the faulty line is disconnected, the critical power grid channel fault monitoring module sends the fault occurrence signal to the mode switching signal module and the short-circuit current calculation module through the communication module when it detects the occurrence of a critical fault. The short-circuit current calculation module obtains the current operating mode of the power grid and matches the current operating mode of the power grid with the short-circuit current calculation result set of each node of the power grid under the various typical operating modes to obtain the short-circuit current calculation result of each node of the power grid under the current operating mode of the power grid. The current operating mode of the power grid is based on the fact that the grid-type energy storage adopts the grid-type control mode as the calculation premise. The short-circuit current calculation module, based on the short-circuit current calculation results of each node of the power grid under the current operating mode of the power grid, selects the short-circuit current calculation results of the power grid nodes with high short-circuit current levels and risks of exceeding limits, as the first target short-circuit current calculation results. The power grid nodes with high short-circuit current levels and risks of exceeding limits are the power grid nodes whose short-circuit current values ​​reach a preset percentage of their upper limit. The short-circuit current calculation module sends the calculation result of the first target short-circuit current to the mode switching signal module.

4. The method of claim 2, wherein, Also includes: After a fault occurs on a critical power grid line and the faulty line is disconnected, the critical power grid channel fault monitoring module, upon detecting the disconnection of the faulty line, sends the fault disconnection signal to the mode switching signal module and the short-circuit current calculation module via the communication module. The short-circuit current calculation module matches the short-circuit current calculation result set of each node of the power grid under the various typical operating modes with the power grid operation mode after the fault line is disconnected, and obtains the short-circuit current calculation result of each node of the power grid after the fault line is disconnected. The power grid operation mode after the fault line is disconnected is based on the calculation premise that the grid-type energy storage adopts the grid-type control mode. The short-circuit current calculation module, based on the short-circuit current calculation results of each node in the power grid after the fault line is disconnected, selects the short-circuit current calculation results of power grid nodes with high short-circuit current levels and risks of exceeding limits, as the second target short-circuit current calculation results. The power grid nodes with high short-circuit current levels and risks of exceeding limits are power grid nodes whose short-circuit current values ​​reach a preset percentage of their upper limit. The short-circuit current calculation module sends the calculation result of the second target short-circuit current to the mode switching signal module.

5. The method of claim 1, wherein, Based on the first target short-circuit current calculation result sent by the short-circuit current calculation module, it is determined whether the switching from grid-type energy storage to grid-type control mode before the fault line is disconnected causes the short-circuit current of the grid node to exceed the limit, including: Before determining whether the faulty line is disconnected, if the grid-type energy storage switches to the grid-type control mode, is there a first target short-circuit current calculation result sent by the short-circuit current calculation module that is greater than or equal to the node short-circuit current upper limit? 6. The method of claim 1, wherein, Based on the second target short-circuit current calculation result sent by the short-circuit current calculation module, it is determined whether the switching of grid-type energy storage to grid-type control mode after the fault line is disconnected causes the short-circuit current of the grid node to exceed the limit, including: After the faulty line is disconnected, if the grid-type energy storage switches to the grid-type control mode, is there a second target short-circuit current calculation result sent by the short-circuit current calculation module that is greater than or equal to the node short-circuit current upper limit? 7. The method of claim 1, wherein, The critical line fault is a three-phase permanent N-2 or Nm fault in an important transmission channel of the power grid, where m>2, and the fault may cause voltage instability risks.

8. The method of claim 1, wherein, The preparatory control mode is specifically as follows: ； In the formula, This represents the amount of phase compensation required for network pre-synchronization. This indicates the amount of voltage compensation required for pre-synchronization of the network. , , , All of these represent parameters of the proportional-integral controller. This indicates that the phase-locked loop follows the phase of the power grid. Indicates the output phase of the network. This indicates the actual voltage value at the grid connection point. This indicates the output voltage of the network.

9. A grid-based energy storage control system considering short-circuit current constraints, comprising a mode switching signal module, a short-circuit current calculation module, a grid critical channel fault monitoring module, a communication module, and grid-based energy storage, wherein the mode switching signal module includes a first memory, a first processor, and a first computer program stored in the first memory and executable on the first processor; the short-circuit current calculation module includes a second memory, a second processor, and a second computer program stored in the second memory and executable on the second processor; the grid critical channel fault monitoring module includes a third memory, a third processor, and a third computer program stored in the third memory and executable on the third processor; the communication module includes a fourth memory, a fourth processor, and a fourth computer program stored in the fourth memory and executable on the fourth processor; and the grid-based energy storage includes a fifth memory, a fifth processor, and a fifth computer program stored in the fifth memory and executable on the fifth processor, characterized in that... When the processor executes the computer program, it implements the steps of the corresponding module in the grid-type energy storage control method considering short-circuit current constraints according to any one of claims 1 to 8.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by the processor, it implements each step of the grid-type energy storage control method considering short-circuit current constraints as described in any one of claims 1 to 8.

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