Capacity analysis method for networking equipment

Abstract

The present application provides a capacity analysis method for networking equipment, which relates to the technical field of networking equipment capacity planning. The capacity analysis method includes: setting the minimum short-circuit current that the networking equipment needs to provide; according to the capacity and per-unit value of the internal impedance of the networking equipment, the selected short-circuit point and the nominal value of the internal impedance of the networking equipment, determining the system impedance between the networking equipment and the short-circuit point to determine whether the system enters a current limiting state, and calculating the system short-circuit current; determining whether the difference between the system short-circuit current and the minimum short-circuit current meets the judgment condition; if the judgment condition is met, verifying the low-voltage tripping risk of the remaining load in the system, and outputting the final capacity configuration result of the networking equipment. According to the corresponding relationship between the capacity of the networking equipment and the short-circuit current considering the current limiting state, the optimization is carried out to obtain the minimum configuration plan of the networking equipment, so as to solve the problem of insufficient protection sensitivity in the weak power grid and independent microgrid supported by the networking equipment.

Description

Technical Field

[0001] The present application relates to the technical field of capacity planning of networking equipment, and in particular to a capacity analysis method for networking equipment. Background Art

[0002] In recent years, with the acceleration of the construction of new power systems, large-scale new energy and large-capacity power electronic equipment have been connected to the grid one after another, and grid-connected and off-grid high-proportion new energy power systems supported by grid-building equipment have emerged. Unlike strong power grids, the voltage of such weak power grids or independent microgrids is mostly established by grid-building equipment. When a short-circuit fault occurs at the end load, there will be problems such as small short-circuit current, difficulty in avoiding normal load current, and insufficient sensitivity of overcurrent protection. This puts forward certain requirements for the capacity configuration of the grid-building equipment in weak power grids or independent microgrids. In addition, in order to achieve instantaneous power support during transient periods, the grid-building equipment must have a certain overcurrent capacity, that is, output a higher multiple of current in a short time. At the same time, in order to prevent short-circuit current from damaging power electronic devices, grid-building equipment needs to set a current limiting link, that is, the short-circuit current output of the grid-building equipment is a nonlinear response with current limiting characteristics. Conventional relay protection setting methods are difficult to adapt to short-circuit calculations involving single or multiple grid-building devices.

[0003] Therefore, how to judge the current limiting situation of networking equipment under different short-circuit points, calculate the short-circuit current provided by networking equipment with current limiting characteristics under different short-circuit points, quantitatively analyze the minimum networking equipment capacity that meets the protection sensitivity requirements, and take into account the low-voltage tripping risk of the remaining load during short-circuit faults, is the key to determining the networking energy storage capacity in weak power grids and independent microgrids. Summary of the invention

[0004] In order to solve at least one of the above problems, the present application proposes a capacity analysis method for networking equipment.

[0005] According to the first aspect of the present application, at least one embodiment of the present application provides a capacity analysis method for networking equipment, including: A. setting the minimum short-circuit current that the networking equipment needs to provide; B. preliminarily selecting the capacity of the networking equipment, and calculating the nominal value of the internal impedance of the networking equipment based on the capacity of the networking equipment and the nominal value of the internal impedance; C. determining the system impedance between the networking equipment and the short-circuit point based on the selected short-circuit point and the nominal value of the internal impedance of the networking equipment to determine whether the system enters a current limiting state, and calculating the system short-circuit current; D. determining whether the difference between the system short-circuit current and the minimum short-circuit current meets a first judgment condition; E. determining whether the difference between the system short-circuit current and the minimum short-circuit current meets a first judgment condition; and E. determining whether the difference between the system short-circuit current and the minimum short-circuit current meets a first judgment condition. When the first judgment condition is met, determine whether the system short-circuit current is greater than the minimum short-circuit current, and: when the system short-circuit current is less than or equal to the minimum short-circuit current, increase the capacity of the networking equipment and execute step B; F. when the system short-circuit current is greater than the minimum short-circuit current, reduce the capacity of the networking equipment and execute step B; when the difference between the system short-circuit current and the minimum short-circuit current meets the first judgment condition, output the capacity of the networking equipment at this time; G. calculate the voltage at the low-voltage bus of the system after the end short-circuit fault occurs to verify the low-voltage tripping risk of the remaining load in the system, and output the final capacity configuration result of the networking equipment.

[0006] For example, in some embodiments of the present application, the setting of the minimum short-circuit current that the networking device needs to provide includes: calculating the minimum short-circuit current according to a setting principle that satisfies the overcurrent protection sensitivity and reliably avoids the overcurrent protection setting value:

[0007]

[0008] in, is the minimum short-circuit current, is the overcurrent protection sensitivity, is the overcurrent protection setting value.

[0009] For example, in some embodiments of the present application, the setting principle that satisfies the overcurrent protection sensitivity and reliably avoids the overcurrent protection setting value includes: avoiding at least one of the maximum load current of the system, avoiding the transformer excitation surge current in the system, and avoiding the maximum starting current of the motor in the system.

[0010] For example, in some embodiments of the present application, in step C, it is determined whether the system enters a current limiting state according to the following formula:

[0011]

[0012]

[0013] in, is the system impedance, is the per unit value of the system impedance based on the network equipment as the reference capacity, The per unit value of the system impedance based on its own capacity or a pre-selected capacity. The per unit internal impedance designed for the networking equipment, , are the rated capacity of the networking equipment and the system benchmark capacity, respectively. Set the overcurrent multiple of the networking device.

[0014] For example, in some embodiments of the present application, in step C, the system short-circuit current is calculated according to the following formula:

[0015] In the case where the system enters the current limiting state:

[0016]

[0017] When the system does not enter the current limiting state:

[0018]

[0019] in, is the system short-circuit current, is the overcurrent multiple setting value of the networking equipment, is the bus voltage reference value of the networking equipment, is the rated capacity of the networking equipment, is the per unit value of the system impedance based on the network equipment as the reference capacity, The per unit value of the internal impedance designed for the networking equipment.

[0020] For example, in some embodiments of the present application, the first determination condition is:

[0021]

[0022] in, is the system short-circuit current, is the minimum short-circuit current, It is the deviation threshold value that satisfies the short-circuit current condition.

[0023] For example, in some embodiments of the present application, the deviation threshold value includes at least one of a set value and a floating value proportional to the system short-circuit current.

[0024] For example, in some embodiments of the present application, when the system short-circuit current is less than or equal to the minimum short-circuit current, the capacity of the networking device is increased; and when the system short-circuit current is greater than the minimum short-circuit current, the capacity of the networking device is reduced, the capacity of the networking device is calculated using the following formula:

[0025]

[0026] in, is the capacity of the networking device, is the increment of networking equipment capacity after each cycle. the capacity of the networking equipment after it is increased or decreased, is the system short-circuit current, is the minimum short-circuit current.

[0027] For example, in some embodiments of the present application, the increment of the networking device capacity after each cycle includes at least one of a set value and a floating step proportional to the increment of the networking device capacity after each cycle.

[0028] For example, in some embodiments of the present application, in step G, the voltage at the low voltage bus is calculated according to the following formula:

[0029]

[0030] in, is the voltage per unit value at the low voltage bus when the end load is short-circuited, is the voltage threshold value for the end load to enter low voltage ride-through, is the system short-circuit current, is the nominal impedance value of the end load, is the voltage reference value of the low-voltage bus.

[0031] According to the second aspect of the present application, at least one embodiment of the present application provides a device, comprising: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors execute a method as described in any one of the first aspects.

[0032] According to a third aspect of the present application, at least one embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method as described in any one of the first aspects is implemented.

[0033] Through the above-mentioned example embodiments, the present application provides a capacity analysis method for networking equipment, which judges the current limiting state through the overall impedance of the system between the short-circuit point and the ideal voltage source of the network, solves the problem that traditional relay protection setting is difficult to adapt to the nonlinear response of the current limiting characteristics of the networking equipment, and carries out optimization according to the correspondence between the capacity of the networking equipment and the short-circuit current considering the current limiting state, so as to obtain the minimum configuration scheme of the networking equipment that meets the sensitivity requirements, and solves the problem of insufficient protection sensitivity in the weak power grid and independent microgrid supported by the networking equipment. The method has a clear process and logic, and is easy to program to realize the automatic generation of the capacity configuration scheme of the networking equipment considering the current limiting characteristics under the protection sensitivity constraint.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] By describing in detail exemplary embodiments thereof with reference to the accompanying drawings, the above and other objects, features and advantages of the present application will become more apparent. The accompanying drawings described below are only some embodiments of the present application, and are not intended to limit the present application.

[0036] Figure 1 The first embodiment of an exemplary schematic diagram of capacity analysis of networking equipment is shown;

[0037] Figure 2 A second embodiment of an exemplary schematic diagram of network equipment capacity analysis is shown;

[0038] Figure 3 A flow chart showing a method for capacity analysis of a networking device according to an exemplary embodiment;

[0039] Figure 4 A structural diagram of an electronic device provided by the present application is shown. DETAILED DESCRIPTION

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0041] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices, etc. may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0042] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0043] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0044] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present application, and therefore cannot be used to limit the scope of protection of the present application.

[0045] Figure 1 The first embodiment of an exemplary schematic diagram of capacity analysis of networking equipment is shown.

[0046] like Figure 1 As shown, the schematic diagram of the capacity analysis method of networking equipment considering the current limiting characteristics under the protection sensitivity constraint includes: a networking ideal voltage source 101, a networking equipment internal impedance 102 and a system impedance 103.

[0047] Figure 2 Structure and Figure 1 Similar, the only difference is that Figure 2 Also included: a load impedance 104 . Figure 1 Applicable to the capacity analysis method of network equipment without considering the low-voltage load tripping constraint; Figure 2 It is applicable to the capacity analysis method of network equipment under the condition of considering the low-voltage load tripping constraint.

[0048] The networking equipment mentioned in this application can maintain the internal potential amplitude and phase angle without significant changes within a certain period of time after the fault occurs, but its DC power supply side must have relatively stable energy support. The DC power supply side can be energy storage, capacitors, supercapacitors, wind power, photovoltaic and other components, corresponding to networking equipment, networking SVG, static synchronous phase regulator, networking wind power, networking photovoltaic and other types of networking equipment. In order to achieve instantaneous power support during transient periods, the networking equipment must have a certain overcurrent capacity, that is, output a higher multiple of current for a short time. At the same time, in order to prevent short-circuit current from damaging power electronic devices, the networking equipment needs to be equipped with a current limiting link, that is, the short-circuit current output of the networking equipment is a nonlinear response with current limiting characteristics, which will bring challenges to the setting of conventional relay protection.

[0049] Figure 3 A flow chart of a method for capacity analysis of a networking device according to an exemplary embodiment is shown.

[0050] like Figure 3 As shown, the capacity analysis method for networking equipment includes steps S301-S307.

[0051] In step S301, the minimum short-circuit current that the networking equipment needs to provide is set.

[0052] According to the setting principle of satisfying the overcurrent protection sensitivity and reliably avoiding the overcurrent protection setting value, calculate the minimum short-circuit current:

[0053]

[0054] in, is the minimum short-circuit current, is the overcurrent protection sensitivity, It is the setting value of overcurrent protection.

[0055] According to some embodiments, the setting principle of satisfying the overcurrent protection sensitivity and reliably avoiding the overcurrent protection setting value includes: avoiding at least one of the maximum load current of the system, avoiding the transformer excitation inrush current in the system, and avoiding the maximum starting current of the motor in the system.

[0056] In step S302, the capacity of the networking device is preliminarily selected, and the nominal value of the internal impedance of the networking device is calculated according to the capacity of the networking device and the per unit value of the internal impedance.

[0057] In step S303, the system impedance between the networking device and the short-circuit point is determined according to the selected short-circuit point and the nominal value of the internal impedance of the networking device to determine whether the system enters a current limiting state and calculate the system short-circuit current.

[0058] System impedance It is the impedance between the short-circuit point and the networking equipment. It comprehensively reflects the impedance characteristics of the system grid structure and each component in the network. It is a representation of the electrical distance between the short-circuit point and the networking equipment.

[0059] This application determines whether the system enters the current limiting state according to the following formula:

[0060]

[0061]

[0062] in, is the system impedance, is the per unit value of the system impedance based on the network equipment capacity, The per unit value of the system impedance based on its own capacity or a pre-selected capacity. The per unit value of the internal impedance designed for the networking equipment, , They are the rated capacity of the network equipment and the system benchmark capacity. Set the overcurrent multiple value for the networking equipment.

[0063] When the system enters the current limiting state, the system short-circuit current is calculated according to the following formula:

[0064]

[0065] When the system does not enter the current limiting state, calculate the system short-circuit current according to the following formula:

[0066]

[0067] in, is the system short-circuit current, It is the setting value of the overcurrent multiple of the network equipment. is the bus voltage reference value of the network equipment, is the rated capacity of the network equipment, is the per unit value of the system impedance based on the network equipment capacity, The per unit value of internal impedance designed for networking equipment.

[0068] In step S304, it is determined whether the difference between the system short-circuit current and the minimum short-circuit current satisfies a first determination condition.

[0069] According to an example embodiment, the first determination condition is:

[0070]

[0071] in, is the system short-circuit current, is the minimum short-circuit current, It is the deviation threshold value that satisfies the short-circuit current condition.

[0072] According to an exemplary embodiment, the deviation threshold value includes: a set value, and at least one of a floating value proportional to the system short-circuit current. The present application only takes this as an example, but is not limited thereto.

[0073] If the first determination condition is met, go to step S306; if the first determination condition is not met, go to step S305.

[0074] In step S305 , when the difference between the system short-circuit current and the minimum short-circuit current does not satisfy the first determination condition, it is determined whether the system short-circuit current is greater than the minimum short-circuit current.

[0075] In step S3051, when the system short-circuit current is less than or equal to the minimum short-circuit current, the capacity of the networking equipment is increased, the capacity of the networking equipment is calculated using the following formula, and the process returns to step S302.

[0076]

[0077] In step S3052, when the system short-circuit current is greater than the minimum short-circuit current, the capacity of the networking equipment is reduced, the capacity of the networking equipment is calculated using the following formula, and the process returns to step S302.

[0078]

[0079] in, To build the capacity of the network equipment, is the increment of networking equipment capacity after each cycle. To increase or decrease the capacity of network equipment, is the system short-circuit current, is the minimum short-circuit current.

[0080] According to some embodiments, the increment of the networking device capacity after each cycle includes: a set value, and at least one of a floating step proportional to the increment of the networking device capacity after each cycle. This application only takes this as an example, but is not limited to this.

[0081] According to some embodiments, comparing the system short circuit current With minimum short circuit current Afterwards, when modifying the capacity of the network equipment, you can increase or decrease the fixed or floating step after each cycle. (i.e. the method above), you can also use the input network equipment capacity At least one of the dichotomy method and the trial position method, this application only takes this as an example, but is not limited to this.

[0082] In step S306, when the difference between the system short-circuit current and the minimum short-circuit current meets the first determination condition, the capacity of the networked device at this time is output.

[0083] In step S307, the voltage condition at the low-voltage bus after the terminal short-circuit fault occurs is calculated to check the low-voltage tripping risk of the remaining loads in the system, and output the final capacity configuration result of the network equipment.

[0084] The low-voltage load tripping constraint refers to the low-voltage tripping risk constraint of other loads on the connected busbar after a short-circuit fault occurs at the end of a single load.

[0085] According to an example embodiment, the voltage at the low voltage bus is calculated as follows:

[0086]

[0087] in, is the voltage per unit value at the low voltage bus when the end load is short-circuited, is the voltage threshold value for the end load to enter low voltage ride-through, is the system short-circuit current, is the nominal impedance value of the end load, It is the voltage reference value of the low voltage bus.

[0088] When the voltage per unit value at the low-voltage bus is less than the voltage reference value of the low-voltage bus, it is considered that other loads enter low-voltage penetration, and the entire system is at risk of losing a large number of loads. At this time, it is necessary to further increase the capacity of the network equipment until the low-voltage penetration conditions are no longer met, or to make further requirements on the low-voltage penetration characteristics of the load.

[0089] The networking equipment capacity analysis method provided in this application is based on a single networking device and off-grid operation mode. However, according to the "superposition theorem" (the response of any branch of a linear circuit containing multiple independent sources is equal to the algebraic sum of the responses of each independent source acting alone), this application is also applicable to the capacity analysis of networking equipment with multiple networking devices and grid-connected modes. It is only necessary to superimpose the responses of multiple networking power sources or equivalent power sources of the large power grid.

[0090] The present application provides a capacity analysis method for networking equipment, which determines the current limiting state through the overall impedance of the system from the short-circuit point to the ideal voltage source of the networking, solves the problem that traditional relay protection setting is difficult to adapt to the nonlinear response of the current limiting characteristics of the networking equipment, and optimizes the corresponding relationship between the capacity of the networking equipment and the short-circuit current considering the current limiting state to obtain the minimum configuration scheme of the networking equipment that meets the sensitivity requirements, thereby solving the problem of insufficient protection sensitivity in the weak power grid and independent microgrid supported by the networking equipment. The method has a clear process and logic, and is easy to program to realize the automatic generation of the capacity configuration scheme of the networking equipment considering the current limiting characteristics under the protection sensitivity constraint.

[0091] Figure 4 A structural diagram of an electronic device provided by the present application is shown.

[0092] See also Figure 4 , Figure 4 An electronic device is provided, comprising a processor and a memory. The memory stores computer instructions. When the computer instructions are executed by the processor, the processor executes the computer instructions to achieve the following Figure 3 The method and refinement scheme shown.

[0093] It should be understood that the above-mentioned device embodiments are only illustrative, and the device disclosed in the present application can also be implemented in other ways. For example, the division of units / modules in the above-mentioned embodiments is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0094] In addition, unless otherwise specified, each functional unit / module in each embodiment of the present application may be integrated into one unit / module, each unit / module may exist physically separately, or two or more units / modules may be integrated together. The above-mentioned integrated unit / module may be implemented in the form of hardware or in the form of a software program module.

[0095] If the integrated unit / module is implemented in the form of hardware, the hardware may be a digital circuit, an analog circuit, etc. The physical implementation of the hardware structure includes but is not limited to transistors, memristors, etc. Unless otherwise specified, the processor or chip may be any appropriate hardware processor, such as CPU, GPU, FPGA, DSP, and ASIC, etc. Unless otherwise specified, the on-chip cache, off-chip memory, and storage may be any appropriate magnetic storage medium or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random-Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc.

[0096] If the integrated unit / module is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present disclosure. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0097] The present application also provides a non-transitory computer storage medium storing a computer program. When the computer program is executed by multiple processors, the processors execute the following Figure 3 The method and refinement scheme shown.

[0098] It should be clearly understood that the present application describes how to form and use specific examples, but the present application is not limited to any details of these examples. On the contrary, based on the teaching of the content disclosed in the present application, these principles can be applied to many other embodiments.

[0099] In addition, it should be noted that the above figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is easy to understand that the processes shown in the above figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0100] The exemplary embodiments of the present application are specifically shown and described above. It should be understood that the present application is not limited to the detailed structures, configurations or implementations described herein; on the contrary, the present application is intended to cover various modifications and equivalent configurations included in the spirit and scope of the appended claims.

Claims

1. A capacity analysis method for networking equipment, characterized in that: include: A. Setting the minimum short-circuit current required to be provided by the network equipment; B. preliminarily selecting the capacity of the networking device, and calculating the nominal value of the internal impedance of the networking device according to the capacity of the networking device and the per unit value of the internal impedance; C. According to the selected short-circuit point and the nominal value of the internal impedance of the networking device, determine the system impedance between the networking device and the short-circuit point to determine whether the system enters a current limiting state, and calculate the system short-circuit current, wherein: Determine whether the system has entered the current limiting state according to the following formula: in, is the system impedance, is the per unit value of the system impedance based on the network equipment as the reference capacity, The per unit value of the system impedance based on its own capacity or a pre-selected capacity. The per unit internal impedance designed for the networking equipment, , are the rated capacity of the networking equipment and the system benchmark capacity, respectively. Setting a value for the overcurrent multiple of the networking equipment; D. determining whether the difference between the system short-circuit current and the minimum short-circuit current satisfies a first determination condition; E. When the difference between the system short-circuit current and the minimum short-circuit current does not satisfy the first determination condition, determine whether the system short-circuit current is greater than the minimum short-circuit current, and: When the system short-circuit current is less than or equal to the minimum short-circuit current, the capacity of the networking equipment is increased, and step B is performed; When the system short-circuit current is greater than the minimum short-circuit current, reducing the capacity of the networking equipment and executing step B; F. When the difference between the system short-circuit current and the minimum short-circuit current satisfies the first determination condition, outputting the capacity of the networking device at this time; G. Calculate the voltage at the low-voltage bus of the system after a terminal short-circuit fault occurs to verify the low-voltage tripping risk of the remaining load in the system, and output the final capacity configuration result of the network equipment.

2. The capacity analysis method according to claim 1, characterized in that: The step of setting the minimum short-circuit current that the networking equipment needs to provide includes: According to the setting principle of satisfying the overcurrent protection sensitivity and reliably avoiding the overcurrent protection setting value, the minimum short-circuit current is calculated: in, is the minimum short-circuit current, is the overcurrent protection sensitivity, is the overcurrent protection setting value.

3. The capacity analysis method according to claim 2, characterized in that: The setting principles for satisfying the overcurrent protection sensitivity and reliably avoiding the overcurrent protection setting value include: At least one of avoiding a maximum load current of the system, avoiding a transformer excitation inrush current in the system, and avoiding a maximum starting current of a motor in the system is avoided.

4. The capacity analysis method according to claim 1, characterized in that: In step C, the system short-circuit current is calculated according to the following formula: In the case where the system enters a current limiting state: When the system does not enter the current limiting state: in, is the system short-circuit current, is the overcurrent multiple setting value of the networking equipment, is the bus voltage reference value of the networking equipment, is the rated capacity of the networking equipment, is the per unit value of the system impedance based on the network equipment as the reference capacity, The per unit value of the internal impedance designed for the networking equipment.

5. The capacity analysis method according to claim 1, characterized in that: The first determination condition is: in, is the system short-circuit current, is the minimum short-circuit current, It is the deviation threshold value that satisfies the short-circuit current condition.

6. The capacity analysis method according to claim 5, characterized in that: The deviation threshold value includes at least one of a set value and a floating value proportional to the system short-circuit current.

7. The capacity analysis method according to claim 1, characterized in that: When the system short-circuit current is less than or equal to the minimum short-circuit current, increasing the capacity of the networking equipment; And in the step of reducing the capacity of the networking equipment when the system short-circuit current is greater than the minimum short-circuit current, the capacity of the networking equipment is calculated using the following formula: in, is the capacity of the networking device, is the increment of the capacity of the networking equipment after each cycle. the capacity of the networking equipment after it is increased or decreased, is the system short-circuit current, is the minimum short-circuit current.

8. The capacity analysis method according to claim 7, characterized in that: The increment of the networking device capacity after each cycle includes at least one of a set value and a floating step that is proportional to the increment of the networking device capacity after each cycle.

9. The capacity analysis method according to claim 1, characterized in that: In step G, calculate the voltage at the low voltage bus according to the following formula: in, is the voltage per unit value at the low voltage bus when the end load is short-circuited, is the voltage threshold value for the end load to enter low voltage ride-through, is the system short-circuit current, is the nominal impedance value of the end load, is the voltage reference value of the low-voltage bus.

10. A capacity analysis device for networking equipment, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors execute the method according to any one of claims 1 to 9.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 9 is implemented.

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