Method, system and equipment for calculating influence degree of grid-connected equipment on transient frequency stability of power system and medium

Abstract

The invention discloses a method, a system and equipment for calculating the influence degree of grid-connected equipment on transient frequency stability of a power system, and a medium. The method comprises the following steps: determining a network equation, node frequency and active power data of the grid-connected equipment during a transient period through primary time domain simulation; for each time point, calculating the sensitivity of the active power of the grid-connected equipment to the active power of a branch connected with an inflow node according to a network equation; according to the node frequency, the active power of the grid-connected equipment and the sensitivity, calculating the influence degree of the grid-connected equipment on the transient frequency stability of the node; and summarizing the transient frequency stability influence degrees of the grid-connected equipment on all the nodes to obtain the transient frequency stability influence degree of the grid-connected equipment on the power system. According to the method, the influence of all the grid-connected devices on the transient frequency stability of the power system in different time periods can be evaluated only through one-time simulation, a decision basis is provided for optimization control of the grid-connected devices, and the calculation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of power system security and stability analysis, and particularly to a method, system, device and medium for calculating the influence degree of grid-connected equipment on the transient frequency stability of a power system. Background Art

[0002] Frequency stability is one of the core indicators to ensure the safety of power equipment and the normal operation of a power system. Transient frequency stability refers to the ability of a power system to maintain or restore the system frequency within an acceptable range after being subjected to a large disturbance, without frequency oscillation or collapse. Currently, the transient frequency stability of the system is judged based on whether the duration of the system frequency being lower or higher than a set threshold value after a large disturbance is greater than a set duration. With the large-scale grid connection of new energy and the increasing proportion of DC transmission, the equivalent inertia of the system continues to decrease, the frequency regulation resources are unevenly distributed, and the spatio-temporal distribution characteristics of the system frequency after a large disturbance are becoming more prominent, and the problem of transient frequency stability is becoming increasingly prominent.

[0003] The existing technology calculates the transient frequency margin based on the transient frequency curve of the bus after a disturbance, and uses the perturbation method to calculate the sensitivity of the change in the active power of a node or the frequency regulation control parameter of a device to the transient frequency stability margin, as an index to measure the influence degree of the active power of a node or the control parameter of a device on the transient frequency stability. Using the existing technology to obtain the influence degree of a single variable requires two-time domain simulation calculations. For a large-scale power system, the computational amount for obtaining the influence degrees of all grid-connected equipment is huge, and it is difficult to meet the requirements of online evaluation and decision-making. Summary of the Invention

[0004] Object of the Invention: The present invention aims to provide a calculation method for determining the influence degrees of all grid-connected equipment on the transient frequency stability of a power system based on a single-time domain simulation; another object of the present invention is to provide a system, device and medium for calculating the influence degrees of grid-connected equipment on the transient frequency stability of a power system.

[0005] Technical Solution: The method for calculating the influence degrees of grid-connected equipment on the transient frequency stability of a power system according to the present invention includes:

[0006] For a preset power system operating state and a preset disturbance, obtain the network equations at each time point during the transient process, the frequencies of each preset node, and the active power injected into the power grid by each preset grid-connected equipment through a single-time domain simulation;

[0007] For each time point within a preset transient time period, calculate the sensitivity of the active power injected into the power grid by each preset grid-connected equipment to the active power of each branch connected to each preset node respectively according to the network equation corresponding to each time point;

[0008] For each preset grid-connected device and each preset node, respectively calculate the influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient period according to the preset node frequency, the active power injected into the power grid by the preset grid-connected device, and the sensitivity of the active power of each preset grid-connected device injected into the power grid to the active power flowing into each branch connected to the preset node.

[0009] For each preset grid-connected device, respectively calculate the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period according to the influence degree of the preset grid-connected device on the transient frequency stability of each preset node during the preset transient period.

[0010] As an optimal scheme of the calculation method for the influence degree of grid-connected devices on the transient frequency stability of the power system, wherein: the transient frequency stability is divided into two categories: transient low-frequency stability and transient high-frequency stability.

[0011] As an optimal scheme of the calculation method for the influence degree of grid-connected devices on the transient frequency stability of the power system, wherein:

[0012] The influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient period includes the influence degree of the preset grid-connected device on the transient low-frequency stability of the preset node during the preset transient period, and the calculation formula is:

[0013]

[0014] Wherein, λ b.fd is the influence degree of the preset grid-connected device on the transient low-frequency stability of the preset node b during the preset transient period, n is the number of time points during the preset transient period, f b.i is the frequency of the preset node b at the i-th time point during the preset transient period, f r is the rated frequency of the power grid, α is a set parameter, and α is greater than 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected into the power grid by the preset grid-connected device at the i-th time point during the preset transient period to the active power flowing into the branch l connected to the preset node b, P i 、P i+1 are respectively the active power injected into the power grid by the preset grid-connected device at the i-th time point and the (i + 1)-th time point during the preset transient period, t i 、t i+1 are respectively the moments corresponding to the i-th time point and the (i + 1)-th time point during the preset transient period, f d.cr is the frequency threshold value in the transient low-frequency stability criterion, β is a set parameter, and β is greater than 1;

[0015] If f b.i ≥βf d.cr (i = 1, 2,..., n - 1), then λ b.fd takes the value of 0.

[0016] As an optimal scheme for a calculation method of the influence degree of grid-connected equipment on the transient frequency stability of a power system, where:

[0017] The influence degree of the preset grid-connected equipment on the transient frequency stability of the preset node within the preset transient period further includes the influence degree of the preset grid-connected equipment on the transient high-frequency stability of the preset node within the preset transient period, and the calculation formula is:

[0018]

[0019] Where, λ b.fu is the influence degree of the preset grid-connected equipment on the transient high-frequency stability of the preset node b within the preset transient period, n is the number of time points within the preset transient period, f b.i is the frequency of the preset node b at the i-th time point within the preset transient period, f r is the rated frequency of the power grid, α is a set parameter, and α is greater than 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected by the preset grid-connected equipment into the power grid at the i-th time point within the preset transient period to the active power flowing into the branch l connected to the preset node b, P i 、P i+1 are respectively the active power injected by the preset grid-connected equipment into the power grid at the i-th time point and the (i + 1)-th time point within the preset transient period, t i 、t i+1 are respectively the moments corresponding to the i-th time point and the (i + 1)-th time point within the preset transient period, f u.cr is the frequency threshold value in the transient high-frequency stability criterion, γ is a set parameter, and γ is greater than 0 and less than 1;

[0020] If f b.i ≤γf u.cr (i = 1, 2,..., n - 1), then the value of λ b.fu is 0.

[0021] As an optimal scheme for a calculation method of the influence degree of grid-connected equipment on the transient frequency stability of a power system, where:

[0022] The influence degree of the preset grid-connected equipment on the transient frequency stability of the power system within the preset transient period includes the influence degree of the preset grid-connected equipment on the transient low-frequency stability of the power system within the preset transient period, and the calculation formula is:

[0023]

[0024] Where, λ fd is the influence degree of the preset grid-connected equipment on the transient low-frequency stability of the power system within the preset transient period, and B is a set of preset nodes.

[0025] As a preferred solution for the calculation method of the influence degree of grid-connected equipment on the transient frequency stability of the power system, where:

[0026] The influence degree of the preset grid-connected equipment on the transient frequency stability of the power system within the preset transient period further includes the influence degree of the preset grid-connected equipment on the transient high-frequency stability of the power system within the preset transient period, and the calculation formula is:

[0027]

[0028] where λ fu is the influence degree of the preset grid-connected equipment on the transient high-frequency stability of the power system within the preset transient period, and B is the preset node set.

[0029] The calculation system for the influence degree of the grid-connected equipment on the transient frequency stability of the power system according to the present invention includes:

[0030] A time-domain simulation calculation module, configured to obtain the network equations at each time point, the frequencies of each preset node, and the active power injected into the power grid by each preset grid-connected equipment during the transient process through a single time-domain simulation for a preset power system operating state and a preset disturbance;

[0031] An active power sensitivity calculation module, configured to calculate the active power sensitivity of the active power injected into the power grid by each preset grid-connected equipment to the active power flowing into each branch connected to each preset node according to the network equations corresponding to each time point within the preset transient period;

[0032] A node influence degree calculation module, configured to calculate the influence degree of the preset grid-connected equipment on the transient frequency stability of the preset node within the preset transient period according to the preset node frequency, the active power injected into the power grid by the preset grid-connected equipment, and the sensitivity of the active power injected into the power grid by each preset grid-connected equipment to the active power flowing into each branch connected to each preset node within the preset transient period;

[0033] A power system influence degree calculation module, configured to calculate the influence degree of the preset grid-connected equipment on the transient frequency stability of the power system within the preset transient period according to the influence degree of the preset grid-connected equipment on the transient frequency stability of each preset node within the preset transient period.

[0034] The calculation device according to the present invention includes:

[0035] A memory and a processor;

[0036] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the one or more programs are executed by the one or more processors, the one or more processors implement the calculation method for the influence degree of the grid-connected equipment on the transient frequency stability of the power system as described in any embodiment of the present invention.

[0037] The computer-readable storage medium of the present invention stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system is realized.

[0038] Beneficial effects: The present invention can give the influence degrees of all grid-connected devices in the power grid on the transient low-frequency stability and transient high-frequency stability of the power system at different time periods during the transient process with only one-time time-domain simulation calculation, providing a decision-making basis for various grid-connected devices such as power sources, loads, energy storage, and direct current for transient frequency stability optimization control, and can improve the calculation efficiency of the optimization decision-making. Description of the Drawings

[0039] Figure 1 It is a flowchart of the calculation method of the present invention. Detailed Embodiments

[0040] The method for calculating the influence degree of the grid-connected device of the present invention on the transient frequency stability of the power system includes:

[0041] S1: For a preset power system operating state and a preset disturbance, obtain the network equations at each time point during the transient process, the frequencies of each preset node, and the active power injected into the power grid by each preset grid-connected device through one-time time-domain simulation;

[0042] It should be noted that the change amount of the active power injected by the power device into the power grid and the sensitivity of the active power injected by the power device into the power grid to the active power of the branch connected to the inflow node are two key factors for the power device to affect the node frequency.

[0043] S2: For each time point within a preset transient time period, calculate the sensitivity of the active power injected by each preset grid-connected device into the power grid to the active power of each branch connected to each preset node according to the network equation corresponding to each time point;

[0044] S3: For each preset grid-connected device and each preset node, calculate the influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient time period according to the preset node frequency, the active power injected by the preset grid-connected device into the power grid, and the sensitivity of the active power injected by each preset grid-connected device into the power grid to the active power of each branch connected to each preset node during the preset transient time period;

[0045] In the embodiment of the present application, the influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient time period includes the influence degree of the preset grid-connected device on the transient low-frequency stability of the preset node, and the calculation formula is:

[0046]

[0047] Where λ b.fdis the transient low-frequency stability influence degree of the preset grid-connected device on the preset node b within the preset transient period, n is the number of time points within the preset transient period, and f b.i is the frequency of the preset node b at the i-th time point within the preset transient period, f r is the rated grid frequency, α is a set parameter, and α > 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected by the preset grid-connected device into the grid at the i-th time point within the preset transient period to the active power flowing into the branch l connected to the preset node b, P i 、P i+1 are the active powers injected by the preset grid-connected device into the grid at the i-th time point and the (i + 1)-th time point within the preset transient period respectively, t i 、t i+1 are the corresponding moments at the i-th time point and the (i + 1)-th time point within the preset transient period respectively, f d.cr is the frequency threshold value in the transient low-frequency stability criterion, β is a set parameter, and β > 1;

[0048] If f b.i ≥βf d.cr (i = 1, 2,..., n - 1), then λ b.fd takes the value of 0.

[0049] In the embodiment of the present application, the influence degree of the preset grid-connected device on the transient frequency stability of the preset node within the preset transient period further includes the influence degree of the preset grid-connected device on the transient high-frequency stability of the preset node, and the calculation formula is:

[0050]

[0051] where λ b.fu is the transient high-frequency stability influence degree of the preset grid-connected device on the preset node b within the preset transient period, n is the number of time points within the preset transient period, and f b.i is the frequency of the preset node b at the i-th time point within the preset transient period, f r is the rated grid frequency, α is a set parameter, and α > 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected by the preset grid-connected device into the grid at the i-th time point within the preset transient period to the active power flowing into the branch l connected to the preset node b, P i 、P i+1 are the active powers injected by the preset grid-connected device into the grid at the i-th time point and the (i + 1)-th time point within the preset transient period respectively, t i 、t i+1 are the corresponding moments at the i-th time point and the (i + 1)-th time point within the preset transient period respectively, f u.cris the frequency threshold value in the transient high-frequency stability criterion, γ is a set parameter, where γ is greater than 0 and less than 1;

[0052] If f b.i ≤ γf u.cr (i = 1, 2,..., n - 1), then λ b.fu takes the value of 0.

[0053] Specifically, α is usually set to 2; β is usually set to [1 + 0.8(f r - f d.cr ) / f d.cr ], γ is usually set to [1 - 0.8(f u.cr - f r ) / f u.cr ], where f r is the rated frequency of the power grid.

[0054] S4: For each preset grid-connected device, calculate the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period respectively according to the influence degree of the preset grid-connected device on the transient frequency stability of each preset node during the preset transient period.

[0055] In the embodiment of the present application, the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period includes the influence degree of the preset grid-connected device on the transient low-frequency stability of the power system during the preset transient period, and the calculation formula is:

[0056]

[0057] Among them, λ fd is the influence degree of the preset grid-connected device on the transient low-frequency stability of the power system during the preset transient period, and B is the preset node set.

[0058] In the embodiment of the present application, the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period further includes the influence degree of the preset grid-connected device on the transient high-frequency stability of the power system during the preset transient period, and the calculation formula is:

[0059]

[0060] Among them, λ fu is the influence degree of the preset grid-connected device on the transient high-frequency stability of the power system during the preset transient period, and B is the preset node set.

[0061] The influence degree of the preset grid-connected equipment on the transient low-frequency (high-frequency) stability of the power system obtained by the above method can determine the direction of the influence of the grid-connected equipment on the transient low-frequency (high-frequency) stability of the power system according to the positive and negative. A positive influence degree indicates that the grid-connected equipment is beneficial to the transient low-frequency (high-frequency) stability of the power system, and a negative influence degree indicates that the grid-connected equipment is not conducive to the transient low-frequency (high-frequency) stability of the power system. At the same time, the degree of influence of the grid-connected equipment on the transient low-frequency (high-frequency) stability of the power system can also be determined according to the magnitude of the influence degree. If the influence degree is positive, the larger the value, the more beneficial the grid-connected equipment is to the transient low-frequency (high-frequency) stability of the power system; if the influence degree is negative, the smaller the value, the more unfavorable the grid-connected equipment is to the transient low-frequency (high-frequency) stability of the power system; if the influence degree is 0, it indicates that the grid-connected equipment has no influence on the transient low-frequency (high-frequency) stability of the power system.

[0062] After obtaining the influence of all grid-connected devices on the transient low-frequency (high-frequency) stability of the power system through the above method, for grid-connected devices with positive influence, the influence can be sorted from large to small. Under the condition of a certain adjustment amount, the higher the influence of the grid-connected devices with higher ranking injected into the grid on the transient low-frequency stability of the power system, the better, and the higher the influence of the grid-connected devices with higher ranking injected into the grid on the transient high-frequency stability of the power system, the better. For grid-connected devices with negative influence, the influence can be sorted from small to large. Under the condition of a certain adjustment amount, the higher the influence of the grid-connected devices with higher ranking injected into the grid on the transient low-frequency stability of the power system, the better, and the higher the influence of the grid-connected devices with higher ranking injected into the grid on the transient high-frequency stability of the power system, the better.

[0063] It should be noted that in the embodiment of the present application, transient frequency stabilization includes two types: transient low-frequency stabilization and transient high-frequency stabilization.

[0064] The above is a schematic scheme of the method for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system in this embodiment. It should be noted that the technical scheme of the system for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system and the technical scheme of the method for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system are of the same concept. For details not described in detail in the technical scheme of the system for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system in this embodiment, please refer to the description of the technical scheme of the method for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system.

[0065] The system for calculating the influence of the grid-connected equipment on the transient frequency stability of the power system of the present invention comprises:

[0066] The time domain simulation calculation module is used to obtain the network equations at each time point in the transient process, the frequency of each preset node, and the active power injected into the grid by each preset grid-connected device through a time domain simulation for the preset power system operating state and preset disturbance;

[0067] An active power sensitivity calculation module, which is used to calculate the active power sensitivity of the active power injected into the power grid by each preset grid-connected device to each branch connected to each preset node according to the network equations corresponding to each time point during a preset transient period for each time point.

[0068] A node influence degree calculation module, which is used to calculate the influence degree of a preset grid-connected device on the transient frequency stability of a preset node during a preset transient period according to the preset node frequency, the active power injected into the power grid by the preset grid-connected device, and the sensitivity of the active power injected into the power grid by each preset grid-connected device to each branch connected to each preset node during the preset transient period for each preset grid-connected device and each preset node.

[0069] A power system influence degree calculation module, which is used to calculate the influence degree of a preset grid-connected device on the transient frequency stability of the power system during a preset transient period according to the influence degree of the preset grid-connected device on the transient frequency stability of each preset node during the preset transient period for each preset grid-connected device.

[0070] This embodiment also provides a computing device applicable to the case of calculating the influence degree of grid-connected devices on the transient frequency stability of the power system, including:

[0071] A memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the method for calculating the influence degree of grid-connected devices on the transient frequency stability of the power system as proposed in the above embodiment.

[0072] This embodiment also provides a storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the method for calculating the influence degree of grid-connected devices on the transient frequency stability of the power system as proposed in the above embodiment.

[0073] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0074] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0075] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0076] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

Claims

1. A method for calculating the influence degree of grid-connected equipment on the transient frequency stability of a power system, characterized in that, It includes the following steps: (1) For a preset power system operating state and a preset disturbance, obtain the network equations at each time point during the transient process, the frequencies of each preset node, and the active power injected into the power grid by each preset grid-connected device through a single-time domain simulation; (2) For each time point during the transient process, calculate the sensitivity of the active power injected into the power grid by each preset grid-connected device to the active power flowing into each branch connected to each preset node according to the network equation corresponding to each time point; (3) For each preset grid-connected device and each preset node, calculate the influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient period according to the frequency of the preset node obtained in step (1), the active power injected into the power grid by the preset grid-connected device, and the sensitivity of the active power injected into the power grid by each preset grid-connected device to the active power flowing into each branch connected to each preset node obtained in step (2); (4) For each preset grid-connected device, calculate the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period according to the influence degree of the preset grid-connected device on the transient frequency stability of each preset node during the preset transient period obtained in step (3).

2. The calculation method for the influence degree of the grid-connected device on the transient frequency stability of the power system according to claim 1, wherein The transient frequency stability includes transient low-frequency stability and transient high-frequency stability.

3. The method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system according to claim 2, wherein, The influence degree of the preset grid-connected device on the transient low-frequency stability of the preset node during the preset transient period is Among them, λ b.fd is the transient low-frequency stability influence degree of the preset grid-connected equipment on the preset node b during the preset transient period, n is the total number of time points during the preset transient period, f b.i is the frequency of the preset node b at the i-th time point during the preset transient period, f r is the rated frequency of the power grid, α is a set parameter, and α is greater than 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected by the preset grid-connected equipment into the power grid at the i-th time point during the preset transient period to the active power flowing into the branch l connected to the preset node b, P i and P i+1 respectively represent the active power injected by the preset grid-connected equipment into the power grid at the i-th time point and the (i + 1)-th time point during the preset transient period, t i and t i+1 respectively represent the moments corresponding to the i-th time point and the (i + 1)-th time point during the preset transient period, f d.cr is the frequency threshold value in the transient low-frequency stability criterion, and β is a set parameter, and β is greater than 1; If f b.i ≥βf d.cr (i = 1, 2, ..., n - 1), then λ b.fd takes the value of 0.

4. The method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system according to claim 3, wherein, α is 2; β is [1 + 0.8(f r - f d.cr ) / f d.cr .

5. The method for calculating the influence degree of grid-connected equipment on the transient frequency stability of a power system according to claim 2, characterized in that, The influence degree of the preset grid-connected device on the transient high-frequency stability of the preset node during the preset transient period is Among them, λ b.fu is the transient high-frequency stability influence degree of the preset grid-connected equipment on the preset node b during the preset transient period, n is the total number of time points during the preset transient period, f b.i is the frequency of the preset node b at the i-th time point during the preset transient period, f r is the rated frequency of the power grid, α is a set parameter, and α is greater than 0; m b is the number of branches connected to the preset node b, S b.f.l.i is the sensitivity of the active power injected by the preset grid-connected equipment into the power grid at the i-th time point during the preset transient period to the active power flowing into the branch l connected to the preset node b, P i and P i+1 respectively represent the active power injected by the preset grid-connected equipment into the power grid at the i-th time point and the (i + 1)-th time point during the preset transient period, t i and t i+1 respectively represent the corresponding moments at the i-th time point and the (i + 1)-th time point during the preset transient period, f u.cr is the frequency threshold value in the transient high-frequency stability criterion, and γ is a set parameter, where γ is greater than 0 and less than 1; If f b.i ≤γf u.cr (i = 1, 2, ..., n - 1), then λ b.fu takes the value of 0.

6. The method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system according to claim 5, wherein α is 2 and γ is [1 - 0.8(f u.cr - f r ) / f u.cr .

7. The method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system according to claim 3 or 4, characterized in that, The influence degree of the preset grid-connected device on the transient low-frequency stability of the power system during the preset transient period is Among them, λ fd is the transient low-frequency stability influence degree of the preset grid-connected equipment on the power system during the preset transient period, and B is the preset node set.

8. The method for calculating the influence degree of grid-connected equipment on the transient frequency stability of a power system according to claim 5 or 6, characterized in that, The influence degree of the preset grid-connected device on the transient high-frequency stability of the power system during the preset transient period is Among them, λ fu is the transient high-frequency stability influence degree of the preset grid-connected equipment on the power system during the preset transient period, and B is the preset node set.

9. A system for calculating the influence degree of the grid-connected device according to any one of claims 1 to 8 on the transient frequency stability of the power system, characterized in that, It includes: A time-domain simulation calculation module, which is used to obtain the network equations at each time point during the transient process, the frequencies of each preset node, and the active power injected into the power grid by each preset grid-connected device through a single-time domain simulation for a preset power system operating state and a preset disturbance; An active power sensitivity calculation module, which is used to calculate the sensitivity of the active power injected into the power grid by each preset grid-connected device to the active power flowing into each branch connected to each preset node according to the network equation corresponding to each time point during the preset transient period; A node influence degree calculation module, which is used to calculate the influence degree of the preset grid-connected device on the transient frequency stability of the preset node during the preset transient period for each preset grid-connected device and each preset node according to the frequency of the preset node, the active power injected into the power grid by the preset grid-connected device, and the sensitivity of the active power injected into the power grid by each preset grid-connected device to the active power flowing into each branch connected to each preset node during the preset transient period; A power system influence degree calculation module, which is used to calculate the influence degree of the preset grid-connected device on the transient frequency stability of the power system during the preset transient period for each preset grid-connected device according to the influence degree of the preset grid-connected device on the transient frequency stability of each preset node during the preset transient period; 10. A computing device, comprising: A memory and a processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system described in any one of claims 1 to 8 are implemented.

11. A computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are executed by a processor, the steps of the method for calculating the influence degree of the grid-connected device on the transient frequency stability of the power system according to any one of claims 1 to 8 are implemented.

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