Method and device for assessing transient voltage stability risk of direct current feeding heavy load area

Abstract

The application provides a method and device for evaluating transient voltage stability risk of direct current feeding heavy load area, the method comprising: constructing an electromagnetic transient simulation model and obtaining initial voltages of all nodes; setting a fault set and constructing bus node voltage response curves; combining a preset threshold value to calculate voltage influence factors, time influence factors and post-fault steady-state voltage influence factors; obtaining transient voltage stability risk indexes of each node under each fault type and then obtaining corresponding risk comprehensive indexes of each node. By constructing the electromagnetic transient simulation model, the transient voltage stability risk indexes of different fault types can be calculated, the influence of different types of faults on the stability risk is effectively considered in the risk evaluation process, the risk comprehensive indexes are obtained through calculation, effective quantification is realized, a reference basis can be provided for control of power system safety and stability, and the application is more suitable for actual production engineering.

Description

Technical Field

[0001] This invention relates to the field of power grid risk assessment, and in particular to a method, apparatus, terminal equipment, and computer-readable storage medium for assessing transient voltage stability risks in DC-fed areas with heavy loads. Background Technology

[0002] DC-fed areas with heavy loads contain various fault scenarios, and how to conduct transient voltage stability risk assessment for these different fault scenarios has become crucial for the stable operation of the power system. Existing transient voltage stability risk assessment methods mainly extract the voltage response trajectory after a fault and then propose corresponding transient voltage stability risk assessment indicators. Common indicators include constructing a binary table consisting of a fixed voltage drop threshold and its maximum allowable duration. However, this method cannot perform refined analysis of transient voltage stability risk assessment. For example, it cannot effectively quantify the risk or consider the impact of different types of faults on the risk, which is not conducive to the research and formulation of safety and stability control measures. Summary of the Invention

[0003] This invention provides a method, apparatus, terminal equipment, and computer-readable storage medium for assessing transient voltage stability risks in DC-fed heavy-load areas. It comprehensively considers the impact of various types of risks on transient voltage stability and quantifies the stability risks, thereby solving the problem that existing technologies cannot perform refined analysis of transient voltage stability risk assessment.

[0004] To address the aforementioned technical problems, embodiments of the present invention provide a method for assessing transient voltage stability risks in DC-fed heavy-load areas, comprising:

[0005] An electromagnetic transient simulation model is constructed for the DC-fed heavy-load region to be evaluated, and the initial voltage of all nodes is obtained based on the electromagnetic transient simulation model.

[0006] A fault set is set up for the fault type to be evaluated. Electromagnetic transient simulation is performed on the fault set, and the bus node voltage response curve under the fault set is constructed based on the initial voltage. The fault set contains several fault types.

[0007] Based on the bus node voltage response curve and a preset voltage threshold value, the voltage influence factor is calculated; based on the bus node voltage response curve and a preset voltage threshold duration, the time influence factor is calculated; based on the bus node voltage response curve and a preset threshold value for voltage recovery to steady state after a fault, the steady-state voltage influence factor after a fault is calculated.

[0008] Based on the calculated voltage influence factor, time influence factor, and post-fault steady-state voltage influence factor, transient voltage stability risk indicators for each node under each fault type are obtained. Based on each transient voltage stability risk indicator and the preset fault factor, a comprehensive risk indicator for each node is obtained.

[0009] As a preferred embodiment, the formula for calculating the transient voltage stability risk index of each node under each of the aforementioned fault types is as follows:

[0010]

[0011] Where i is the i-th node, j is the j-th fault type, and H V H is the voltage influence factor. T H is the time-related factor. Vnew The steady-state voltage influence factor after the fault, t f Voltage V f(i,j) The voltage drops below the voltage threshold value V. TH At that moment, τ f Voltage V f(i,j) Restored to the voltage threshold value V TH At the above times, n represents the voltage V. f(i,j) There are n drops below the voltage threshold value V TH K SSC It is a stable influencing factor and a zero-one variable.

[0012] As a preferred embodiment, the formula for calculating the voltage influence factor is:

[0013]

[0014] Among them, H V(i,j) The voltage influence factor for the j-th fault type at the i-th node.

[0015] As a preferred embodiment, the formula for calculating the post-fault steady-state voltage influence factor is as follows:

[0016]

[0017] Among them, H Vnew V is the post-fault steady-state voltage influence factor. fnew This is the value when the voltage recovers to a steady state after the fault.

[0018] As a preferred embodiment, the formula for calculating the post-fault steady-state voltage influence factor is as follows:

[0019]

[0020] Among them, H VnewV is the post-fault steady-state voltage influence factor. fnew This is the value when the voltage recovers to a steady state after the fault.

[0021] As a preferred embodiment, the formula for calculating the comprehensive risk index is as follows:

[0022]

[0023] Among them, H i Let σ be the comprehensive risk index corresponding to node i. i The fault factor is determined based on operating mode factors and fault probability factors.

[0024] Accordingly, embodiments of the present invention provide a transient voltage stability risk assessment device for DC-fed heavy-load areas, including a simulation module, a curve construction module, a calculation module, and a comprehensive assessment module; wherein,

[0025] The simulation module is used to construct an electromagnetic transient simulation model for the DC-fed heavy load region to be evaluated, and to obtain the initial voltage of all nodes based on the electromagnetic transient simulation model.

[0026] The curve construction module is used to set up a fault set for the fault type to be evaluated, and to construct the bus node voltage response curve under the fault set based on the initial voltage by performing electromagnetic transient simulation on the fault set; wherein, the fault set includes several fault types.

[0027] The calculation module is used to calculate the voltage influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold value; to calculate the time influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold duration; and to calculate the post-fault steady-state voltage influence factor based on the bus node voltage response curve and in combination with a preset threshold value for voltage recovery to steady state after a fault.

[0028] The comprehensive evaluation module is used to obtain transient voltage stability risk indicators for each node under each fault type based on the calculated voltage influence factor, time influence factor, and post-fault steady-state voltage influence factor, and to obtain a comprehensive risk index for each node based on each transient voltage stability risk index combined with a preset fault factor.

[0029] As a preferred embodiment, the formula for calculating the transient voltage stability risk index of each node under each of the aforementioned fault types is as follows:

[0030]

[0031] Where i is the i-th node, j is the j-th fault type, and HV H is the voltage influence factor. T H is the time-related factor. Vnew The steady-state voltage influence factor after the fault, t f Voltage V f(i,j) The voltage drops below the voltage threshold value V. TH At that moment, τ f Voltage V f(i,j) Restored to the voltage threshold value V TH At the above times, n represents the voltage V. f(i,j) There are n drops below the voltage threshold value V TH K SSC It is a stable influencing factor and a zero-one variable.

[0032] Accordingly, embodiments of the present invention also provide a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the transient voltage stability risk assessment method for DC-fed heavy load areas.

[0033] Accordingly, embodiments of the present invention also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the transient voltage stability risk assessment method for DC-fed heavy load areas.

[0034] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0035] This invention provides a method, apparatus, terminal device, and computer-readable storage medium for transient voltage stability risk assessment in a DC-injected heavy-load area. The transient voltage stability risk assessment method includes: constructing an electromagnetic transient simulation model for the DC-injected heavy-load area to be assessed, and obtaining the initial voltage of all nodes based on the electromagnetic transient simulation model; setting a fault set for the fault types to be assessed, and constructing bus node voltage response curves under the fault set based on the initial voltages by performing electromagnetic transient simulation on the fault set; wherein the fault set includes several fault types; and based on the bus node voltage response curves... The system calculates voltage influence factors based on preset voltage threshold values; time influence factors based on the bus node voltage response curve and preset voltage threshold duration; and post-fault steady-state voltage influence factors based on the bus node voltage response curve and preset threshold values ​​for voltage recovery to steady state after a fault. Based on the calculated voltage influence factors, time influence factors, and post-fault steady-state voltage influence factors, transient voltage stability risk indicators for each node under each fault type are obtained. Finally, based on these transient voltage stability risk indicators and preset fault factors, a comprehensive risk indicator for each node is obtained. By implementing this embodiment of the application and constructing an electromagnetic transient simulation model, voltage influence factors, time influence factors, and post-fault steady-state voltage influence factors can be calculated. This allows for the calculation of transient voltage stability risk indicators for different fault types. The risk assessment process effectively considers the impact of different types of faults on stability risk, and the comprehensive risk indicator is calculated, achieving effective quantification. This provides a reference basis for the safe and stable control of power systems and is more suitable for actual production engineering. Attached Figure Description

[0036] Figure 1 : A schematic flowchart of an embodiment of the transient voltage stability risk assessment method for DC-fed heavy-load areas provided by the present invention.

[0037] Figure 2 : A schematic diagram illustrating the effect of one embodiment of the bus node voltage response curve provided by the present invention.

[0038] Figure 3 : A schematic diagram of an embodiment of the transient voltage stability risk assessment device for DC-fed heavy-load areas provided by the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] Please refer to Figure 1 , Figure 1 A transient voltage stability risk assessment method for a DC-fed heavy-load region, provided by an embodiment of the present invention, includes steps S1 to S4; wherein,

[0042] Step S1: Construct an electromagnetic transient simulation model for the DC-fed heavy-load region to be evaluated, and obtain the initial voltage of all nodes based on the electromagnetic transient simulation model.

[0043] In this embodiment, grid data of the DC-feeded heavy-load area to be evaluated can be obtained, and an electromagnetic transient simulation model of the system can be constructed based on the grid data. It should also be noted that the definition of a DC-feeded heavy-load area is as follows: generally, if a fault occurs within a distance of two 500kV substations from the DC feed point, it may lead to transient voltage instability problems, and in this case, the area can be considered a heavy-load area.

[0044] Based on the electromagnetic transient simulation model, the initial voltages of all nodes can be obtained by running the electromagnetic transient simulation model. These are then used in step S2 to construct the bus node voltage response curves.

[0045] Step S2: Set up a fault set for the fault type to be evaluated, and construct the bus node voltage response curve under the fault set based on the initial voltage by performing electromagnetic transient simulation on the fault set; wherein, the fault set contains several fault types.

[0046] In this embodiment, a fault set can be set for the fault type to be evaluated. The fault set to be evaluated generally depends on the fault type that the researchers need to study, or it can be set according to the type of the area to be evaluated.

[0047] Furthermore, based on the initial voltage, the bus node voltage response curve under the fault set is constructed, referring to... Figure 2 Let the initial voltage of node i be V. 0i The voltage response curve after the fault is V f(t) The value of the voltage when it returns to steady state after the fault is V. fnew During the fault, the voltage is lower than the voltage threshold value V.TH The time periods are denoted as T. f1 ,T f2 …T fn .

[0048] The figure also includes the voltage threshold value V. TH Voltage threshold duration T TH and the threshold value V when the voltage recovers to steady state after a fault THnew These three parameters can be preset before step S2, and the specific setting method can be referred to the requirements for the safe and stable operation of the power grid. More specifically, the voltage threshold value and voltage threshold duration are the low voltage threshold value and low voltage threshold duration, respectively.

[0049] Step S3: Based on the bus node voltage response curve and in combination with a preset voltage threshold value, calculate the voltage influence factor; based on the bus node voltage response curve and in combination with a preset voltage threshold duration, calculate the time influence factor; based on the bus node voltage response curve and in combination with a preset threshold value for voltage recovery to steady state after a fault, calculate the steady-state voltage influence factor after a fault.

[0050] As a further preferred embodiment, the formula for calculating the voltage influence factor is:

[0051]

[0052] Among them, H V(i,j) The voltage influence factor for the j-th fault type at the i-th node.

[0053] The formula for calculating the time influence factor is as follows:

[0054]

[0055] Among them, H T Let T be the time-related factor. f This indicates that the voltage is lower than the voltage threshold value V. TH The time period.

[0056] The formula for calculating the steady-state voltage influence factor after the fault is as follows:

[0057]

[0058] Among them, H Vnew V is the post-fault steady-state voltage influence factor. fnewThis represents the value when the voltage recovers to a steady state after a fault. Implementing this embodiment, based on the bus node voltage response curve and pre-set threshold values, allows for the acquisition of voltage influence factors, time influence factors, and post-fault steady-state voltage influence factors for different nodes and fault types. These three influence factors are used to assess transient voltage stability risk, taking into account factors before, after, and during the fault, thus effectively improving the accuracy of the assessment compared to existing technical solutions.

[0059] Step S4: Based on the calculated voltage influence factor, time influence factor, and post-fault steady-state voltage influence factor, obtain the transient voltage stability risk index of each node under each fault type, and obtain the comprehensive risk index corresponding to each node based on each transient voltage stability risk index combined with the preset fault factor.

[0060] In step S4 above, the formula for calculating the transient voltage stability risk index of each node under each of the aforementioned fault types is as follows:

[0061]

[0062] Where i is the i-th node, j is the j-th fault type, and H V H is the voltage influence factor. T H is the time-related factor. Vnew The steady-state voltage influence factor after the fault, t f Voltage V f(i,j) The voltage drops below the voltage threshold value V. TH At that moment, τ f Voltage V f(i,j) Restored to the voltage threshold value V TH At the above times, n represents the voltage V. f(i,j) There are n drops below the voltage threshold value V TH K SSC For example, when node i is protected by stability control measures under fault j, K is a stability influencing factor and is a zero-to-one variable. SSC(i,j) = 0, otherwise it is 1. The max function represents the value when the voltage drops below V n times after a fault. TH The calculation method is as follows: In implementing the embodiments of this application, the stability impact factor is used to consider whether a safety and stability control system has been put into use in the power grid or not. The calculation of voltage impact factor, time impact factor and post-fault steady-state voltage impact factor is used for evaluation to take into account the main voltage factors, time factors and recovery factors that affect stability risks. This can encompass as many types of fault scenarios in the considered area as possible, which is conducive to the research and formulation of corresponding safety and stability control measures.

[0063] Furthermore, the formula for calculating the comprehensive risk index is as follows:

[0064]

[0065] Among them, H i Let σ be the comprehensive risk index corresponding to node i. i The fault factor is determined based on operating mode factors and fault probability factors.

[0066] By calculating the comprehensive risk index, the weak points of system transient voltage stability risk under fault j in the area to be evaluated can be further identified as max(H). i,j ), i = 1, 2, ... k; and, the comprehensive weak node of the system transient voltage stability risk in the region to be evaluated is max(H i (i = 1, 2, ..., k, etc.) to achieve rapid node location.

[0067] Accordingly, refer to Figure 3 This invention provides a transient voltage stability risk assessment device for DC-fed heavy-load areas, including a simulation module 101, a curve construction module 102, a calculation module 103, and a comprehensive assessment module 104; wherein,

[0068] The simulation module 101 is used to construct an electromagnetic transient simulation model for the DC-fed heavy load region to be evaluated, and to obtain the initial voltage of all nodes based on the electromagnetic transient simulation model.

[0069] The curve construction module 102 is used to set a fault set for the fault type to be evaluated, and to construct the bus node voltage response curve under the fault set based on the initial voltage by performing electromagnetic transient simulation on the fault set; wherein, the fault set includes several fault types.

[0070] The calculation module 103 is used to calculate the voltage influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold value; to calculate the time influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold duration; and to calculate the post-fault steady-state voltage influence factor based on the bus node voltage response curve and in combination with a preset threshold value for voltage recovery to steady state after a fault.

[0071] The comprehensive evaluation module 104 is used to obtain transient voltage stability risk indicators for each node under each fault type based on the calculated voltage influence factor, time influence factor and post-fault steady-state voltage influence factor, and to obtain the comprehensive risk index corresponding to each node based on each transient voltage stability risk index combined with the preset fault factor.

[0072] As a preferred embodiment, the formula for calculating the transient voltage stability risk index of each node under each of the aforementioned fault types is as follows:

[0073]

[0074] Where i is the i-th node, j is the j-th fault type, and H V H is the voltage influence factor. T H is the time-related factor. Vnew The steady-state voltage influence factor after the fault, t f Voltage V f(i,j) The voltage drops below the voltage threshold value V. TH At that moment, τ f Voltage V f(i,j) Restored to the voltage threshold value V TH At the above times, n represents the voltage V. f(i,j) There are n drops below the voltage threshold value V TH K SSC It is a stable influencing factor and a zero-one variable.

[0075] Accordingly, embodiments of the present invention also provide a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the transient voltage stability risk assessment method for DC-fed heavy load areas.

[0076] The processor can 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. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal, connecting various parts of the terminal via various interfaces and lines.

[0077] The memory can be used to store the computer program. The processor implements various functions of the terminal by running or executing the computer program stored in the memory and calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0078] Accordingly, embodiments of the present invention also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the transient voltage stability risk assessment method for DC-fed heavy load areas.

[0079] The module integrated into the transient voltage stability risk assessment device for the DC-fed heavy-load area, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0080] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0081] This invention provides a method, apparatus, terminal device, and computer-readable storage medium for transient voltage stability risk assessment in a DC-injected heavy-load area. The transient voltage stability risk assessment method includes: constructing an electromagnetic transient simulation model for the DC-injected heavy-load area to be assessed, and obtaining the initial voltage of all nodes based on the electromagnetic transient simulation model; setting a fault set for the fault types to be assessed, and constructing bus node voltage response curves under the fault set based on the initial voltages by performing electromagnetic transient simulation on the fault set; wherein the fault set includes several fault types; and based on the bus node voltage response curves... The system calculates voltage influence factors based on preset voltage threshold values; time influence factors based on the bus node voltage response curve and preset voltage threshold duration; and post-fault steady-state voltage influence factors based on the bus node voltage response curve and preset threshold values ​​for voltage recovery to steady state after a fault. Based on the calculated voltage influence factors, time influence factors, and post-fault steady-state voltage influence factors, transient voltage stability risk indicators for each node under each fault type are obtained. Finally, based on these transient voltage stability risk indicators and preset fault factors, a comprehensive risk indicator for each node is obtained. By implementing this embodiment of the application and constructing an electromagnetic transient simulation model, voltage influence factors, time influence factors, and post-fault steady-state voltage influence factors can be calculated. This allows for the calculation of transient voltage stability risk indicators for different fault types. The risk assessment process effectively considers the impact of different types of faults on stability risk, and the comprehensive risk indicator is calculated, achieving effective quantification. This provides a reference basis for the safe and stable control of power systems and is more suitable for actual production engineering.

[0082] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for assessing transient voltage stability risk in a DC-fed heavy-load area, characterized in that, include: An electromagnetic transient simulation model is constructed for the DC-fed heavy-load region to be evaluated, and the initial voltage of all nodes is obtained based on the electromagnetic transient simulation model. A fault set is set up for the fault type to be evaluated. Electromagnetic transient simulation is performed on the fault set, and the bus node voltage response curve under the fault set is constructed based on the initial voltage. The fault set contains several fault types. Based on the bus node voltage response curve and a preset voltage threshold value, the voltage influence factor is calculated; based on the bus node voltage response curve and a preset voltage threshold duration, the time influence factor is calculated; based on the bus node voltage response curve and a preset threshold value for voltage recovery to steady state after a fault, the steady-state voltage influence factor after a fault is calculated. Based on the calculated voltage influence factor, time influence factor, and post-fault steady-state voltage influence factor, the transient voltage stability risk index of each node under each fault type is obtained. Based on each transient voltage stability risk index and the preset fault factor, the comprehensive risk index corresponding to each node is obtained. The formula for calculating the transient voltage stability risk index of each node under each fault type is as follows: ； Where i represents the i-th node, and j represents the j-th fault type. Voltage influence factor, As a time-related factor, This is the influence factor of steady-state voltage after the fault. For voltage Drop below the voltage threshold value At that moment, For voltage Restored to the voltage threshold value At the above times, n represents voltage. There are n drops below the stated voltage threshold value , It is a stable influencing factor and a zero-one variable.

2. The transient voltage stability risk assessment method for DC-fed heavy-load areas as described in claim 1, characterized in that, The formula for calculating the voltage influence factor is as follows: ； in, The voltage influence factor for the j-th fault type at the i-th node.

3. The transient voltage stability risk assessment method for DC-fed heavy-load areas as described in claim 2, characterized in that, The formula for calculating the time influence factor is as follows: ； in, The time-related factor, This indicates that the voltage is below the voltage threshold value. The time period.

4. The transient voltage stability risk assessment method for DC-fed heavy-load areas as described in claim 3, characterized in that, The formula for calculating the steady-state voltage influence factor after the fault is as follows: ； in, V is the post-fault steady-state voltage influence factor. fnew This is the value when the voltage recovers to a steady state after the fault.

5. The transient voltage stability risk assessment method for DC-fed heavy-load areas as described in claim 4, characterized in that, The formula for calculating the comprehensive risk index is as follows: ； Among them, H i Let i be the comprehensive risk index corresponding to node i. The fault factor is determined based on operating mode factors and fault probability factors.

6. A transient voltage stability risk assessment device for DC-fed heavy-load areas, characterized in that, It includes a simulation module, a curve construction module, a calculation module, and a comprehensive evaluation module; among which, The simulation module is used to construct an electromagnetic transient simulation model for the DC-fed heavy load region to be evaluated, and to obtain the initial voltage of all nodes based on the electromagnetic transient simulation model. The curve construction module is used to set up a fault set for the fault type to be evaluated, and to construct the bus node voltage response curve under the fault set based on the initial voltage by performing electromagnetic transient simulation on the fault set; wherein, the fault set includes several fault types. The calculation module is used to calculate the voltage influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold value; to calculate the time influence factor based on the bus node voltage response curve and in combination with a preset voltage threshold duration; and to calculate the post-fault steady-state voltage influence factor based on the bus node voltage response curve and in combination with a preset threshold value for voltage recovery to steady state after a fault. The comprehensive evaluation module is used to obtain transient voltage stability risk indicators for each node under each fault type based on the calculated voltage influence factor, time influence factor and post-fault steady-state voltage influence factor, and to obtain the comprehensive risk index corresponding to each node based on each transient voltage stability risk index combined with the preset fault factor. The formula for calculating the transient voltage stability risk index of each node under each fault type is as follows: ； Where i represents the i-th node, and j represents the j-th fault type. Voltage influence factor, As a time-related factor, This is the influence factor of steady-state voltage after the fault. For voltage Drop below the voltage threshold value At that moment, For voltage Restored to the voltage threshold value At the above times, n represents voltage. There are n drops below the stated voltage threshold value , It is a stable influencing factor and a zero-one variable.

7. A terminal device, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the transient voltage stability risk assessment method for DC-fed heavy-load areas as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform the transient voltage stability risk assessment method for DC-fed heavy-load areas as described in any one of claims 1 to 5.

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