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

Abstract

The invention discloses a method and system for calculating the influence degree of grid-connected equipment on transient voltage stability of a power system, and relates to the field of safety and stability analysis of the power system, and the method comprises the steps: obtaining a network equation, node voltage and active and reactive power data of the grid-connected equipment during a transient period through one time of time domain simulation; for each time point, calculating the sensitivity of the power of the grid-connected equipment to the node voltage by using a network equation; calculating the influence degree of the grid-connected equipment on the transient voltage stability of the node according to the node voltage, the power of the grid-connected equipment and the sensitivity; and summarizing the transient voltage stability influence degree of each grid-connected device on all the nodes to obtain the transient voltage stability influence degree of the grid-connected devices on the power system. According to the method, the influence of all the grid-connected devices on the transient voltage 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 safety and stability analysis, and in particular to a method and system for calculating the influence of grid-connected equipment on transient voltage stability of a power system. Background Art

[0002] Stable voltage is one of the key indicators to ensure the normal operation of power equipment. Transient voltage stability is defined as the ability of all buses in the system to maintain stable voltage after the power system is subjected to a large disturbance. At present, transient voltage stability is judged based on whether the duration of the bus voltage below the set threshold value during the transient process is greater than the set duration. With the continuous increase in the scale of new energy power generation and DC transmission applications, the impact of new energy units disconnecting from the grid due to high voltage and DC transmission systems being locked due to high voltage on the safe and stable operation of the power system is increasing. Whether the duration of the bus voltage above the set threshold value during the transient process is greater than the set duration should also be used as a judgment indicator for transient voltage stability.

[0003] Existing technologies focus on studying transient low voltage stability, calculating transient low voltage stability margin based on bus transient voltage curve, and using perturbation method to calculate the sensitivity of node reactive compensation or equipment reactive voltage control parameter changes to transient low voltage stability margin as an indicator to measure the impact of node reactive compensation or equipment reactive voltage control parameters on transient low voltage stability. To obtain the impact of a variable based on the perturbation method requires two time domain simulation calculations. For large-scale power systems, the amount of calculation required to obtain the impact of all grid-connected devices is huge. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: how to determine the influence of all grid-connected devices on the transient voltage stability of the power system based on a single time-domain simulation calculation.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for calculating the influence of a grid-connected device on the transient voltage stability of a power system, comprising:

[0008] According to the preset power system operating state and preset disturbance, a time domain simulation is performed to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive power injected into the grid by each preset grid-connected device;

[0009] For each time point in the preset transient period, the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device to the voltage of each preset node is calculated according to the network equation corresponding to each time point;

[0010] For each preset grid-connected device and each preset node, the influence of the preset grid-connected device on the transient voltage stability of the preset node during the preset transient period is calculated according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected device, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device during the preset transient period to the voltage of each preset node;

[0011] For each preset grid-connected device, the influence of the preset grid-connected device on the transient voltage stability of the power system during the preset transient period is calculated according to the influence of the preset grid-connected device on the transient voltage stability of each preset node during the preset transient period.

[0012] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0013] The transient voltage stabilization includes two categories: transient low voltage stabilization and transient high voltage stabilization.

[0014] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0015] The step of calculating the sensitivity of active power and reactive power injected into the grid by each preset grid-connected device to the voltage of each preset node includes:

[0016] For devices that only have reactive power connected to the grid, the sensitivity of the active power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0; for devices that only have active power connected to the grid, the sensitivity of the reactive power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0.

[0017] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0018] The influence degree of the preset grid-connected equipment on the transient voltage stability of the preset node during the preset transient period includes the influence degree of the preset grid-connected equipment on the transient low voltage stability of the preset node during the preset transient period, and the calculation formula is:

[0019]

[0020] Among them, λ b.vd is the transient low voltage stability impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is the setting parameter; S b.v.i.p , S b.v.i.qare the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t i is the time corresponding to the i-th time point in the preset transient period, V d.cr is the voltage threshold value in the transient low voltage stability criterion, and β is the setting parameter.

[0021] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0022] The influence of the preset grid-connected equipment on the transient voltage stability of the preset node during the preset transient period also includes the influence of the preset grid-connected equipment on the transient high voltage stability of the preset node during the preset transient period, and the calculation formula is:

[0023]

[0024] Among them, λ b.vu is the transient high voltage impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is a setting parameter, and α is greater than 0; S b.v.i.p , S b.v.i.q are the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t i is the time corresponding to the i-th time point in the preset transient period, V u.cr is the voltage threshold value in the transient high voltage stability criterion, and γ is the setting parameter.

[0025] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0026] The influence degree of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period includes the influence degree of the preset grid-connected equipment on the transient low voltage stability of the power system during the preset transient period, and the calculation formula is:

[0027]

[0028] Among them, λ vd It is the impact of transient low voltage stability of the power system by the preset grid-connected equipment during the preset transient period.

[0029] As a preferred solution for calculating the influence of grid-connected equipment on transient voltage stability of power system:

[0030] The influence degree of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period also includes the influence degree of the preset grid-connected equipment on the transient high voltage stability of the power system during the preset transient period, and the calculation formula is:

[0031]

[0032] Among them, λ vu It is the impact of the transient high voltage stability of the power system on the preset grid-connected equipment during the preset transient period.

[0033] In a second aspect, an embodiment of the present invention provides a system for calculating the influence of a grid-connected device on transient voltage stability of a power system, comprising:

[0034] The time domain simulation calculation module is used to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive 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;

[0035] A voltage sensitivity calculation module is used to calculate the sensitivity of active and reactive power injected into the power grid by each preset grid-connected device to each preset node voltage at each time point within the preset transient period according to the network equation corresponding to each time point;

[0036] A node influence calculation module is used to calculate the influence of the preset grid-connected equipment on the transient voltage stability of the preset nodes during the preset transient period according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected equipment, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected equipment during the preset transient period to the voltage of each preset node, for each preset grid-connected equipment and each preset node;

[0037] The power system impact calculation module is used to calculate the impact of the preset grid-connected equipment on the transient voltage stability of the power system within the preset transient period according to the impact of the preset grid-connected equipment on the transient voltage stability of each preset node within the preset transient period.

[0038] In a third aspect, an embodiment of the present invention provides a computing device, including:

[0039] Memory and processor;

[0040] 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 method for calculating the influence of grid-connected equipment on the transient voltage stability of the power system as described in any embodiment of the present invention.

[0041] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the method for calculating the influence of grid-connected equipment on transient voltage stability of a power system.

[0042] The beneficial effects of the present invention are as follows: the present invention can give the influence of all grid-connected devices in the power grid on the transient low voltage stability and transient high voltage stability of the power system in different time periods of the transient process with only one time-domain simulation calculation, and provide a decision-making basis for various grid-connected devices such as power supply, load, energy storage, reactive power compensation, etc. for transient voltage stability optimization control, which can improve the calculation efficiency of optimization decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0044] Figure 1 It is an overall flow chart of the method for calculating the influence of grid-connected equipment on transient voltage stability of power system described in the first embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0048] Example 1

[0049] Reference Figure 1 , which is the first embodiment of the present invention, and provides a method for calculating the influence of a grid-connected device on the transient voltage stability of a power system, comprising:

[0050] S1: For the preset power system operating state and preset disturbance, a time domain simulation is performed to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive power injected into the grid by each preset grid-connected device;

[0051] It should be noted that the change in active and reactive power injected into the power grid by power equipment and the voltage sensitivity of active and reactive power to nodes in the power grid are two key factors affecting node voltages by power equipment. When the voltage of each node in the power grid is near the rated value, the active voltage sensitivity is relatively small compared to the reactive voltage sensitivity, and when the change in active and reactive power is not much different, the effect of active change on node voltage can be ignored. However, node voltage fluctuates greatly during transient processes, and the effect of active change on node voltage needs to be considered. In addition, the degree of deviation of node voltage relative to the normal value during transient processes and the cumulative effect of the impact of equipment on node voltage need to be considered.

[0052] S2: for each time point in the preset transient period, according to the network equation corresponding to each time point, calculate the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device to the voltage of each preset node;

[0053] In the embodiment of the present application, calculating the sensitivity of active power and reactive power injected into the grid by each preset grid-connected device to each preset node voltage includes:

[0054] For devices that only have reactive power connected to the grid, the sensitivity of the active power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0; for devices that only have active power connected to the grid, the sensitivity of the reactive power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0.

[0055] S3: for each preset grid-connected device and each preset node, respectively, according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected device, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device to the voltage of each preset node during the preset transient period, calculate the influence of the preset grid-connected device on the transient voltage stability of the preset node during the preset transient period;

[0056] In the embodiment of the present application, the influence of the preset grid-connected device on the transient voltage stability of the preset node during the preset transient period includes the influence of the preset grid-connected device on the transient low voltage stability of the preset node during the preset transient period, and the calculation formula is:

[0057]

[0058] Among them, λ b.vd is the transient low voltage stability impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is the setting parameter; S b.v.i.p , S b.v.i.q are the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t i is the time corresponding to the i-th time point in the preset transient period, V d.cr is the voltage threshold value in the transient low voltage stability criterion, and β is the setting parameter.

[0059] In the embodiment of the present application, the influence of the preset grid-connected device on the transient voltage stability of the preset node during the preset transient period also includes the influence of the preset grid-connected device on the transient high voltage stability of the preset node during the preset transient period, and the calculation formula is:

[0060]

[0061] Among them, λ b.vu is the transient high voltage impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is a setting parameter, and α is greater than 0; S b.v.i.p , S b.v.i.q are the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t iis the time corresponding to the i-th time point in the preset transient period, V u.cr is the voltage threshold value in the transient high voltage stability criterion, and γ is the setting parameter.

[0062] Specifically, α is a setting parameter, which is greater than 0 and is usually set to 2; β is a setting parameter, which is greater than 1 and is usually set to 1.1; γ is a setting parameter, which is less than 1 and is usually set to 0.9.

[0063] S4: For each preset grid-connected device, calculate the influence of the preset grid-connected device on the transient voltage stability of the power system during the preset transient period according to the influence of the preset grid-connected device on the transient voltage stability of each preset node during the preset transient period.

[0064] In the embodiment of the present application, the influence of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period includes the influence of the preset grid-connected equipment on the transient low voltage stability of the power system during the preset transient period, and the calculation formula is:

[0065]

[0066] Among them, λ vd It is the impact of transient low voltage stability of the power system by the preset grid-connected equipment during the preset transient period.

[0067] In the embodiment of the present application, the influence of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period also includes the influence of the preset grid-connected equipment on the transient high voltage stability of the power system during the preset transient period, and the calculation formula is:

[0068]

[0069] Among them, λ vu It is the impact of the transient high voltage stability of the power system on the preset grid-connected equipment during the preset transient period.

[0070] It should be noted that in the embodiment of the present application, transient voltage stabilization includes two types: transient low voltage stabilization and transient high voltage stabilization.

[0071] The above is a schematic scheme of the method for calculating the influence of the grid-connected equipment on the transient voltage 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 voltage stability of the power system and the technical scheme of the method for calculating the influence of the grid-connected equipment on the transient voltage stability of the power system in the above embodiment 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 voltage 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 voltage stability of the power system.

[0072] The system for calculating the influence of grid-connected equipment on transient voltage stability of power system in this embodiment includes:

[0073] The time domain simulation calculation module is used to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive 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;

[0074] A voltage sensitivity calculation module is used to calculate the sensitivity of active and reactive power injected into the power grid by each preset grid-connected device to each preset node voltage at each time point within the preset transient period according to the network equation corresponding to each time point;

[0075] A node influence calculation module is used to calculate the influence of the preset grid-connected equipment on the transient voltage stability of the preset nodes during the preset transient period according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected equipment, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected equipment during the preset transient period to the voltage of each preset node, for each preset grid-connected equipment and each preset node;

[0076] The power system impact calculation module is used to calculate the impact of the preset grid-connected equipment on the transient voltage stability of the power system within the preset transient period according to the impact of the preset grid-connected equipment on the transient voltage stability of each preset node within the preset transient period.

[0077] This embodiment further provides a computing device, which is applicable to the method for calculating the influence of grid-connected equipment on transient voltage stability of power system, and includes:

[0078] A memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method for calculating the influence of grid-connected equipment on transient voltage stability of the power system as proposed in the above embodiment.

[0079] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for calculating the influence of grid-connected equipment on transient voltage stability of the power system proposed in the above embodiment is implemented.

[0080] The storage medium proposed in this embodiment and the method for calculating the influence of grid-connected equipment on transient voltage stability of power system proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0081] Example 2

[0082] Referring to Tables 1 to 4, an embodiment of the present invention provides a method for calculating the influence of grid-connected equipment on transient voltage stability of a power system. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation experiments.

[0083] Step 1: Time domain simulation and data preparation

[0084] 1. Set simulation parameters:

[0085] Preset the operating status and disturbance conditions of the power system.

[0086] Assume that the power system consists of 5 nodes and 3 grid-connected devices. Each device injects active and reactive power at different time points.

[0087] 2. Perform time domain simulation:

[0088] Run the simulation program to obtain the network equations at each time point in the transient process.

[0089] The voltage of each node and the active and reactive power data injected into the grid by the grid-connected equipment are obtained, as shown in Table 1:

[0090] Table 1 Node voltage and grid-connected equipment power injection data

[0091]

[0092] Step 2: Sensitivity calculation

[0093] 1. Calculate voltage sensitivity:

[0094] For each time point, the network equation is used to calculate the sensitivity of the active and reactive power injected into the grid by the preset grid-connected equipment to the voltage of each preset node.

[0095] For grid-connected devices with only reactive power, the sensitivity of active power to node voltage is set to 0; for grid-connected devices with only active power, the sensitivity of reactive power to node voltage is set to 0. The results are shown in Table 2:

[0096] Table 2 Node voltage sensitivity calculation results

[0097]

[0098] Step 3: Calculate the impact

[0099] 1. Calculate the impact of low voltage stability:

[0100] For each preset node, within the preset transient period, the influence of the preset grid-connected equipment on the transient low voltage stability is calculated based on the voltage and sensitivity at each time point.

[0101] Record the calculation results and consider whether the node voltage is below the low voltage threshold.

[0102] 2. Calculate the impact of high voltage stability:

[0103] For each preset node, within the preset transient period, the influence of the preset grid-connected equipment on the transient high voltage stability is calculated based on the voltage and sensitivity at each time point.

[0104] Record the calculation results and consider whether the node voltage is above the high voltage threshold. The results are shown in Table 3:

[0105] Table 3 Voltage stability impact assessment results

[0106]

[0107]

[0108] Step 4: Calculate system impact

[0109] 1. Calculate the impact of grid-connected equipment on transient voltage stability of the power system:

[0110] For each grid-connected device, the impact of the device on the transient low voltage and high voltage stability of the entire power system is calculated in combination with its impact on the transient voltage stability of all preset nodes.

[0111] The results are summarized to evaluate the contribution and impact of each grid-connected device on system stability. The results are shown in Table 4:

[0112] Table 4 System impact calculation results

[0113] Grid-connected equipment number Total low voltage stability impact Total high voltage stability impact 1 -0.000659 0 2 -0.000707 0 … … …

[0114] Simulation results:

[0115] 1. Data Collection:

[0116] Assume that the data obtained by simulation includes the voltage value of each node at different time points and the injected power data of the grid-connected equipment.

[0117] The calculated sensitivity value of each node and the influence of each grid-connected device on the node voltage.

[0118] 2. Impact Assessment:

[0119] The calculation results of low voltage stability impact and high voltage stability impact show that some grid-connected equipment has a greater impact on node voltage stability, especially under high disturbance conditions.

[0120] Through system impact calculation, the impact of grid-connected equipment on the overall stability of the power system was evaluated, and it was found that some equipment had a significant impact on the system voltage stability during transient processes.

[0121] This simulation example successfully calculated the impact of grid-connected equipment on the transient voltage stability of the power system. Through system sensitivity analysis and impact assessment, we can better understand the role of each grid-connected equipment on the stability of the power system, thereby providing data support for the optimization management of the power grid.

[0122] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for calculating the influence of grid-connected equipment on transient voltage stability of power system, characterized in that: include: According to the preset power system operating state and preset disturbance, a time domain simulation is performed to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive power injected into the grid by each preset grid-connected device; For each time point in the preset transient period, the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device to the voltage of each preset node is calculated according to the network equation corresponding to each time point; For each preset grid-connected device and each preset node, the influence of the preset grid-connected device on the transient voltage stability of the preset node during the preset transient period is calculated according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected device, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected device during the preset transient period to the voltage of each preset node; For each preset grid-connected device, the influence of the preset grid-connected device on the transient voltage stability of the power system during the preset transient period is calculated according to the influence of the preset grid-connected device on the transient voltage stability of each preset node during the preset transient period.

2. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 1, characterized in that: The transient voltage stabilization includes two categories: transient low voltage stabilization and transient high voltage stabilization.

3. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 2, characterized in that: The step of calculating the sensitivity of active power and reactive power injected into the grid by each preset grid-connected device to each preset node voltage includes: For devices that only have reactive power connected to the grid, the sensitivity of the active power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0; for devices that only have active power connected to the grid, the sensitivity of the reactive power injected into the grid by the preset grid-connected device to the voltage of each preset node is set to 0.

4. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 3, characterized in that: The influence degree of the preset grid-connected equipment on the transient voltage stability of the preset node during the preset transient period includes the influence degree of the preset grid-connected equipment on the transient low voltage stability of the preset node during the preset transient period, and the calculation formula is: Among them, λ b.vd is the transient low voltage stability impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is the setting parameter; S b.v.i.p , S b.v.i.q are the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, and P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t i is the time corresponding to the i-th time point in the preset transient period, V d.cr is the voltage threshold value in the transient low voltage stability criterion, and β is the setting parameter.

5. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 4, characterized in that: The influence of the preset grid-connected equipment on the transient voltage stability of the preset node during the preset transient period also includes the influence of the preset grid-connected equipment on the transient high voltage stability of the preset node during the preset transient period, and the calculation formula is: Among them, λ b.vu is the transient high voltage impact of the preset grid-connected equipment on the preset node b during the preset transient period, n is the number of time points in the preset transient period, V b.u 、V b.d are the upper and lower limits of the steady-state voltage of node b, V b.i is the voltage of the preset node b at the i-th time point in the preset transient period, α is a setting parameter, and α is greater than 0; S b.v.i.p , S b.v.i.q are the sensitivity of the active power and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period to the preset node b voltage, respectively, and P i , Q i are respectively the active and reactive power injected into the grid by the preset grid-connected equipment at the i-th time point in the preset transient period, t i is the time corresponding to the i-th time point in the preset transient period, V u.cr is the voltage threshold value in the transient high voltage stability criterion, and γ is the setting parameter.

6. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 5, characterized in that: The influence degree of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period includes the influence degree of the preset grid-connected equipment on the transient low voltage stability of the power system during the preset transient period, and the calculation formula is: Among them, λ vd It is the impact of transient low voltage stability of the power system by the preset grid-connected equipment during the preset transient period.

7. The method for calculating the influence of grid-connected equipment on transient voltage stability of power system according to claim 6, characterized in that: The influence degree of the preset grid-connected equipment on the transient voltage stability of the power system during the preset transient period also includes the influence degree of the preset grid-connected equipment on the transient high voltage stability of the power system during the preset transient period, and the calculation formula is: Among them, λ vu It is the impact of the transient high voltage stability of the power system on the preset grid-connected equipment during the preset transient period.

8. A system using the method for calculating the influence of grid-connected equipment on transient voltage stability of power system as claimed in any one of claims 1 to 7, characterized in that: include: The time domain simulation calculation module is used to obtain the network equations at each time point in the transient process, the voltage of each preset node, and the active and reactive 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; A voltage sensitivity calculation module is used to calculate the sensitivity of active and reactive power injected into the power grid by each preset grid-connected device to each preset node voltage at each time point within the preset transient period according to the network equation corresponding to each time point; A node influence calculation module is used to calculate the influence of the preset grid-connected equipment on the transient voltage stability of the preset nodes during the preset transient period according to the preset node voltage, the active and reactive power injected into the grid by the preset grid-connected equipment, and the sensitivity of the active and reactive power injected into the grid by each preset grid-connected equipment during the preset transient period to the voltage of each preset node, for each preset grid-connected equipment and each preset node; The power system impact calculation module is used to calculate the impact of the preset grid-connected equipment on the transient voltage stability of the power system within the preset transient period according to the impact of the preset grid-connected equipment on the transient voltage stability of each preset node within the preset transient period.

9. A computing device comprising: Memory and 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 of grid-connected equipment on the transient voltage stability of the power system as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for calculating the influence of a grid-connected device on the transient voltage stability of a power system as described in any one of claims 1 to 7.

Images