A method and system for discriminating transient voltage instability risk of power system

Abstract

The application discloses a method and system for judging transient voltage instability risk of a power system, and belongs to the technical field of power system analysis. The method comprises the following steps: obtaining basic data of a distributed new energy power system, and establishing a comprehensive load model of the distributed new energy power system according to the basic data; an analysis model of the distributed new energy power system is established; a continuous power flow algorithm is used for the analysis model, and a P-V curve of the distributed new energy power system in a distributed new energy operation mode is calculated; and based on the P-V curve, a load level boundary of the distributed new energy power system is determined. The operation state of the current distributed new energy power system is determined, and the transient voltage instability risk of the power system is judged based on the operation state and the load level boundary. The transient voltage instability risk of the distributed new energy power system can be predicted through the P-V curve and the load boundary level.

Description

Technical Field

[0001] This invention relates to the field of power system analysis technology, and more specifically, to a method and system for determining the risk of transient voltage instability in a power system. Background Technology

[0002] In recent years, distributed renewable energy generation, represented by rooftop photovoltaics, has experienced explosive growth in my country, becoming an important structural feature of the power system. The high proportion of distributed renewable energy integration has altered the voltage stability characteristics of the power system, leading to transient voltage risks that require analysis. Current technologies cannot fully address this issue.

[0003] Existing technical solutions cannot provide for the potential transient voltage instability risks that may occur in power systems containing distributed renewable energy sources under different load levels. Summary of the Invention

[0004] To address the above problems, this invention proposes a method for determining the risk of transient voltage instability in a power system, comprising:

[0005] Acquire basic data on distributed renewable energy power systems, and establish a comprehensive load model for distributed renewable energy power systems based on the basic data.

[0006] Based on the distributed renewable energy operation mode, the comprehensive load model is adjusted to establish an analysis model of the power system containing distributed renewable energy.

[0007] Using the continuous power flow algorithm for the analysis model, the PV curve of the power system containing distributed renewable energy is calculated under the distributed renewable energy operation mode, and the load level boundary of the power system containing distributed renewable energy is determined based on the PV curve.

[0008] Determine the current operating status of the power system including distributed renewable energy, and identify the transient voltage instability risk of the power system based on the operating status and load level boundaries.

[0009] Optional distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

[0010] Optionally, PV curves for distributed renewable energy power systems may be included, including: constant power mode PV curves and low voltage ride-through mode PV curves.

[0011] Optionally, based on the PV curve, the load level boundary including the distributed renewable energy power system is determined, including:

[0012] The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 1, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 2.

[0013] Optionally, the transient voltage instability risk level includes four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of disconnection from the grid after continuous low voltage ride-through, and risk of voltage collapse.

[0014] Optionally, determine the current operating status of the power system including distributed renewable energy, and based on the operating status and load level boundaries, identify the transient voltage instability risk of the power system, including:

[0015] Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators;

[0016] If the load level is less than the load level corresponding to boundary 1, then the level of transient voltage instability risk is low.

[0017] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists.

[0018] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is lower than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through.

[0019] If the load level is greater than the load level corresponding to boundary 2, the level of transient voltage instability risk is that there is a risk of voltage collapse.

[0020] Furthermore, this invention also proposes a system for determining the risk of transient voltage instability in a power system, comprising:

[0021] The model building unit is used to acquire basic data of the distributed new energy power system and to build a comprehensive load model of the distributed new energy power system based on the basic data.

[0022] The model adjustment unit is used to adjust the comprehensive load model based on the distributed new energy operation mode in order to establish an analysis model of the power system containing distributed new energy.

[0023] The calculation unit is used to calculate the PV curve of the power system containing distributed new energy under the distributed new energy operation mode using the continuous power flow algorithm for the analysis model, and to determine the load level boundary of the power system containing distributed new energy based on the PV curve.

[0024] The discrimination unit is used to determine the current operating status of the power system including distributed new energy sources, and to discriminate the transient voltage instability risk of the power system based on the operating status and load level boundaries.

[0025] Optional distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

[0026] Optionally, PV curves for distributed renewable energy power systems may be included, including: constant power mode PV curves and low voltage ride-through mode PV curves.

[0027] Optionally, based on the PV curve, the load level boundary including the distributed renewable energy power system is determined, including:

[0028] The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 1, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 2.

[0029] Optionally, the transient voltage instability risk level includes four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of disconnection from the grid after continuous low voltage ride-through, and risk of voltage collapse.

[0030] Optionally, the discrimination unit determines the current operating status of the power system including distributed renewable energy, and based on the operating status and load level boundaries, determines the transient voltage instability risk of the power system, including:

[0031] Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators;

[0032] If the load level is less than the load level corresponding to boundary 1, then the level of transient voltage instability risk is low.

[0033] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists.

[0034] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is lower than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through.

[0035] If the load level is greater than the load level corresponding to boundary 2, the level of transient voltage instability risk is that there is a risk of voltage collapse.

[0036] In another aspect, the present invention also provides a computing device, comprising: one or more processors;

[0037] A processor is used to execute one or more programs;

[0038] When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0039] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention proposes a method for identifying the transient voltage instability risk of a power system, comprising: acquiring basic data of a power system containing distributed renewable energy sources; establishing a comprehensive load model of the power system containing distributed renewable energy sources based on the basic data; adjusting the comprehensive load model based on the operating mode of the distributed renewable energy sources to establish an analytical model of the power system containing distributed renewable energy sources; using a continuous power flow algorithm on the analytical model to calculate the PV curve of the power system containing distributed renewable energy sources under the operating mode of distributed renewable energy sources, and determining the load level boundary of the power system containing distributed renewable energy sources based on the PV curve; determining the current operating state of the power system containing distributed renewable energy sources, and identifying the transient voltage instability risk of the power system based on the operating state and the load level boundary. This invention can predict the transient voltage instability risk of a power system containing distributed renewable energy sources by using the PV curve and the load level boundary. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method of the present invention;

[0043] Figure 2 This is a physical structure diagram of the integrated load model of the method of the present invention;

[0044] Figure 3 This is a physical structure diagram of the analytical model of the method of this invention;

[0045] Figure 4This is a schematic diagram of the PV curve and load level boundary of the method of the present invention;

[0046] Figure 5 This is a schematic diagram illustrating the method of the present invention for determining the risk of transient voltage instability.

[0047] Figure 6 This is a structural diagram of the system of the present invention. Detailed Implementation

[0048] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0049] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0050] Example 1:

[0051] This invention proposes a method for determining the risk of transient voltage instability in power systems, such as... Figure 1 As shown, it includes:

[0052] Step 1: Obtain basic data on distributed renewable energy power systems, and establish a comprehensive load model on distributed renewable energy power systems based on the basic data;

[0053] Step 2: Based on the distributed new energy operation mode, adjust the comprehensive load model to establish an analysis model of the power system containing distributed new energy.

[0054] Step 3: Using the continuous power flow algorithm for the analysis model, calculate the PV curve of the power system containing distributed new energy under the distributed new energy operation mode, and determine the load level boundary of the power system containing distributed new energy based on the PV curve.

[0055] Step 4: Determine the current operating status of the power system including distributed new energy sources, and identify the transient voltage instability risk of the power system based on the operating status and load level boundaries.

[0056] Among them, the distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

[0057] The PV curves for distributed renewable energy power systems include: constant power mode PV curves and low voltage ride-through mode PV curves.

[0058] Among them, determining the load level boundary of the distributed renewable energy power system based on the PV curve includes:

[0059] The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 1, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 2.

[0060] The transient voltage instability risk is classified into four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of disconnection from the grid after continuous low voltage ride-through, and risk of voltage collapse.

[0061] This includes determining the current operating status of the power system including distributed renewable energy, and identifying the transient voltage instability risk of the power system based on the operating status and load level boundaries, including:

[0062] Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators;

[0063] If the load level is less than the load level corresponding to boundary 1, then the level of transient voltage instability risk is low.

[0064] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists.

[0065] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is lower than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through.

[0066] If the load level is greater than the load level corresponding to boundary 2, the level of transient voltage instability risk is that there is a risk of voltage collapse.

[0067] The present invention will be further described below with reference to specific implementations:

[0068] The implementation steps include:

[0069] Step 1: Establish a comprehensive load model including distributed renewable energy sources. The physical structure of the model is as follows: Figure 2 As shown.

[0070] Step 2: Improve the parts of the integrated load model related to renewable energy. Distributed renewable energy has two operating modes: constant power mode and low voltage ride-through mode. In constant power mode, distributed renewable energy is modeled as a constant power source. In low voltage ride-through mode, distributed renewable energy is modeled as a controlled current source, and its characteristics before disconnection are represented by formulas (1)-(2). After a period of continuous low voltage ride-through, it is disconnected from the grid. If the system voltage recovers, the renewable energy switches to constant power mode.

[0071] I P =K P1 V t +K P2 I P0 +I Pset (1)

[0072] I Q =K Q1 (V L -V t )+I Qset (2)

[0073] In the formula, I P I represents the active current command during the low-voltage ride-through of new energy sources. Q I represents the reactive current command during the low-voltage ride-through period of new energy sources. P0 This represents the active current of the new energy source before it enters the low-voltage ride-through phase, V. t V represents the terminal voltage of the new energy source. L This represents the threshold voltage for new energy sources to enter low-voltage ride-through, while the other variables are the control parameters for new energy sources.

[0074] Step 3: Based on the models obtained in Steps 1 and 2, establish an analysis model for the power system including distributed renewable energy sources. The structure of the model is as follows: Figure 3 As shown.

[0075] Step 4: Use the continuous power flow algorithm to calculate the system PV curve when the renewable energy source is operating at constant power. Here, P represents the system's load active power level, and V represents the voltage at the load's grid connection point.

[0076] Step 5: Use the continuous power flow algorithm to calculate the system PV curve during low-voltage ride-through of the renewable energy source. Here, P represents the system's load active power level, and V represents the voltage at the load's grid connection point.

[0077] Step 6: Plot the obtained PV curves from steps 4-5 as shown in the figure. Figure 4 As shown

[0078] Step 7: Based on Step 6, and considering the system's operating status and... Figure 4 The boundary position in, and Figure 5To determine the risk of transient voltage instability.

[0079] When the system load level is less than the load level corresponding to boundary ①, the output is "low risk of transient voltage instability"; when the system load level is between the load level corresponding to boundary ① and the load level corresponding to boundary ②, if the voltage at the new energy generator terminal is higher than its low voltage ride-through threshold voltage, the output is "risk of continuous low voltage ride-through after fault exists"; if the voltage at the new energy generator terminal is lower than its low voltage ride-through threshold voltage, the output is "risk of grid disconnection after continuous low voltage ride-through exists"; if the system load level is higher than the load level corresponding to boundary ②, the output is "risk of voltage collapse exists".

[0080] Example 2:

[0081] This invention also proposes a system 200 for determining the risk of transient voltage instability in a power system, such as... Figure 6 As shown, it includes:

[0082] Model building unit 201 is used to acquire basic data of distributed new energy power systems and to build a comprehensive load model of distributed new energy power systems based on the basic data.

[0083] The model adjustment unit 202 is used to adjust the comprehensive load model based on the distributed new energy operation mode in order to establish an analysis model of the power system containing distributed new energy.

[0084] The calculation unit 203 is used to calculate the PV curve of the power system containing distributed new energy under the distributed new energy operation mode using the continuous power flow algorithm for the analysis model, and to determine the load level boundary of the power system containing distributed new energy based on the PV curve.

[0085] The discrimination unit 204 is used to determine the current operating status of the power system including distributed new energy sources, and to discriminate the transient voltage instability risk of the power system based on the operating status and load level boundary.

[0086] Among them, the distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

[0087] The PV curves for distributed renewable energy power systems include: constant power mode PV curves and low voltage ride-through mode PV curves.

[0088] Among them, determining the load level boundary of the distributed renewable energy power system based on the PV curve includes:

[0089] The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 1, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as boundary 2.

[0090] The transient voltage instability risk is classified into four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of disconnection from the grid after continuous low voltage ride-through, and risk of voltage collapse.

[0091] The discrimination unit determines the current operating status of the power system including distributed renewable energy, and judges the transient voltage instability risk of the power system based on the operating status and load level boundaries, including:

[0092] Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators;

[0093] If the load level is less than the load level corresponding to boundary 1, then the level of transient voltage instability risk is low.

[0094] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists.

[0095] If the load level is between the load level corresponding to boundary 1 and the load level corresponding to boundary 2, and the distributed new energy generator terminal voltage is lower than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through.

[0096] If the load level is greater than the load level corresponding to boundary 2, the level of transient voltage instability risk is that there is a risk of voltage collapse.

[0097] This invention can predict the transient voltage instability risk of distributed renewable energy power systems by using PV curves and load boundary levels.

[0098] Example 3:

[0099] Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0100] Example 4:

[0101] Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0102] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention 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 invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0103] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0104] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0105] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0106] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0107] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for determining the risk of transient voltage instability in a power system, characterized in that, The method includes: Acquire basic data on distributed renewable energy power systems, and establish a comprehensive load model for distributed renewable energy power systems based on the basic data. Based on the distributed renewable energy operation mode, the comprehensive load model is adjusted to establish an analysis model of the power system containing distributed renewable energy. Using the continuous power flow algorithm for the analysis model, the PV curve of the power system containing distributed renewable energy is calculated under the distributed renewable energy operation mode, and the load level boundary of the power system containing distributed renewable energy is determined based on the PV curve. Determine the current operating status of the power system including distributed renewable energy sources, and identify the transient voltage instability risk of the power system based on the operating status and load level boundaries; The determination of the load level boundary of the distributed renewable energy power system based on the PV curve includes: The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as the first boundary, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as the second boundary.

2. The method according to claim 1, characterized in that, The distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

3. The method according to claim 1, characterized in that, The PV curves of the distributed renewable energy power system include: constant power mode PV curves and low voltage ride-through mode PV curves.

4. The method according to claim 1, characterized in that, The transient voltage instability risk is classified into four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of grid disconnection after continuous low voltage ride-through, and risk of voltage collapse.

5. The method according to claim 1, characterized in that, The process of determining the current operating status of the power system including distributed renewable energy, and judging the transient voltage instability risk of the power system based on the operating status and load level boundaries, includes: Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators; If the load level is less than the load level corresponding to the first boundary, the transient voltage instability risk level is considered to be low. If the load level is between the load level corresponding to the first boundary and the load level corresponding to the second boundary, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists. If the load level is between the load level corresponding to the first boundary and the load level corresponding to the second boundary, and the voltage at the distributed renewable energy generator terminal is lower than the low voltage ride-through threshold voltage for distributed renewable energy, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through. If the load level is greater than the load level corresponding to the second boundary, the level of transient voltage instability risk is that there is a risk of voltage collapse.

6. A system for determining the risk of transient voltage instability in a power system, characterized in that, The system includes: The model building unit is used to acquire basic data of the distributed new energy power system and to build a comprehensive load model of the distributed new energy power system based on the basic data. The model adjustment unit is used to adjust the comprehensive load model based on the distributed new energy operation mode in order to establish an analysis model of the power system containing distributed new energy. The calculation unit is used to calculate the PV curve of the power system containing distributed new energy under the distributed new energy operation mode using the continuous power flow algorithm for the analysis model, and to determine the load level boundary of the power system containing distributed new energy based on the PV curve. The discrimination unit is used to determine the current operating status of the power system including distributed new energy sources, and to discriminate the transient voltage instability risk of the power system based on the operating status and load level boundary. The determination of the load level boundary of the distributed renewable energy power system based on the PV curve includes: The intersection of the constant power mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as the first boundary, and the intersection of the low voltage ride-through mode PV curve and the low voltage ride-through threshold voltage of distributed renewable energy is taken as the second boundary.

7. The system according to claim 6, characterized in that, The distributed renewable energy operation modes include: constant power mode and low voltage ride-through mode.

8. The system according to claim 6, characterized in that, The PV curves of the distributed renewable energy power system include: constant power mode PV curves and low voltage ride-through mode PV curves.

9. The system according to claim 6, characterized in that, The transient voltage instability risk is classified into four levels: low transient voltage instability risk, risk of continuous low voltage ride-through after a fault, risk of grid disconnection after continuous low voltage ride-through, and risk of voltage collapse.

10. The system according to claim 6, characterized in that, The discrimination unit determines the current operating status of the power system including distributed renewable energy, and judges the transient voltage instability risk of the power system based on the operating status and load level boundaries, including: Based on the aforementioned operating status, determine the current load level of the power system including distributed renewable energy and the terminal voltage of the distributed renewable energy generators; If the load level is less than the load level corresponding to the first boundary, the transient voltage instability risk level is considered to be low. If the load level is between the load level corresponding to the first boundary and the load level corresponding to the second boundary, and the distributed new energy generator terminal voltage is higher than the distributed new energy low voltage ride-through threshold voltage, then the level of transient voltage instability risk is the risk of continuous low voltage ride-through after a fault exists. If the load level is between the load level corresponding to the first boundary and the load level corresponding to the second boundary, and the voltage at the distributed renewable energy generator terminal is lower than the low voltage ride-through threshold voltage for distributed renewable energy, then the level of transient voltage instability risk is the risk of grid disconnection after continuous low voltage ride-through. If the load level is greater than the load level corresponding to the second boundary, the level of transient voltage instability risk is that there is a risk of voltage collapse.

11. A computer device, characterized in that, include: One or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described in any one of claims 1-5 is implemented.

12. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the method as described in any one of claims 1-5.

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