A method and apparatus for improving voltage stability in a power system

Abstract

This application discloses a method and apparatus for improving the voltage stability of a power system. The method includes: establishing a voltage stability assessment model for the power system; collecting real-time data of the power system through a phasor measurement unit; calculating the voltage stability index and angular stability index of the power system using the voltage stability assessment model; identifying all weak nodes in the power system based on the voltage stability index and angular stability index; calculating remedial measures for the power system based on each weak node using a parallel optimization algorithm; and implementing the remedial measures to improve the voltage stability of the power system. Therefore, the voltage stability index and angular stability index provide a faster and more accurate voltage stability assessment. Using a parallel optimization algorithm to calculate remedial measures reduces the optimization calculation time, thereby enabling rapid and accurate voltage stability monitoring and the determination of remedial measures, effectively improving the voltage stability of the power system.

Description

Technical Field

[0001] This application relates to the field of power system stability monitoring and optimization, and more specifically, to a method and apparatus for improving the voltage stability of a power system. Background Technology

[0002] With continuous social development and progress, electricity demand continues to grow. In the existing power system, transmission lines often operate near their transmission capacity limits, which puts enormous pressure on the entire power system and easily leads to voltage collapse. Once voltage collapse occurs, it will cause power supply interruptions, seriously affecting the stability and reliability of the power grid.

[0003] Traditional voltage monitoring and control methods mainly rely on Supervisory Control and Data Acquisition (SCADA) systems and Energy Management Systems (EMS). However, these systems suffer from low data sampling rates, slow communication speeds, and sluggish state estimation processing, making it impossible to acquire voltage and current vectors of the power system in real time, thus hindering effective online voltage control.

[0004] Current voltage stability assessment methods, such as PV and VQ curve analysis and modal analysis, rely heavily on SCADA and EMS data, which limits their ability to acquire system model information and makes them difficult to apply in large-scale power systems. Furthermore, online voltage stability assessment methods based on phasor measurement units (PMUs) are overly reliant on network simplification or require additional information on system topology and generator states, significantly limiting their effectiveness in practical applications.

[0005] Therefore, how to effectively improve the voltage stability of the power system, quickly and accurately monitor voltage stability, and rapidly calculate the optimal solutions for possible remedial measures is a problem that needs to be solved. Summary of the Invention

[0006] In view of the above problems, this application provides a method and apparatus for improving the voltage stability of a power system, so as to effectively improve the voltage stability of the power system, quickly and accurately monitor the voltage stability, and quickly calculate the optimized scheme of possible remedial measures.

[0007] To achieve the above objectives, the following specific solutions are proposed:

[0008] A method for improving the voltage stability of a power system includes:

[0009] Establish a voltage stability assessment model for power systems;

[0010] Real-time data of the power system is acquired through a phasor measurement unit;

[0011] The real-time data is input into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angle stability index of the power system.

[0012] Based on the voltage stability index and the angle stability index, identify all weak points in the power system;

[0013] Based on each weak node, remedial measures to remedy the power system are calculated using a parallel optimization algorithm.

[0014] The remedial measures are performed on the power system to improve the voltage stability of the power system.

[0015] Optionally, based on the voltage stability index and the angle stability index, all weak points in the power system are identified, including:

[0016] In the power system, nodes that exhibit abnormal voltage collapse when the voltage stability index is lower than a first preset threshold or the angle stability index is lower than a second preset threshold are identified as weak nodes.

[0017] Optionally, the real-time data is input into the voltage stability assessment model to enable the voltage stability assessment model to calculate the voltage stability index and angular stability index of the power system, including:

[0018] The real-time data is input into the voltage stability assessment model so that the voltage stability assessment model constructs a Jacobian matrix based on the real-time data, and calculates the voltage stability index of the power system from the inverse and determinant of the Jacobian matrix.

[0019] The Jacobian matrix is ​​transformed to calculate the angular stability index of the power system based on the parameters of the power system and the transformed Jacobian matrix.

[0020] Optionally, the remedial measures for the power system calculated using a parallel optimization algorithm based on each weak node include:

[0021] Based on each weak node, the power system is decomposed into multiple subsystems using the Newton-Raphson algorithm, and the subsystems are interconnected.

[0022] Each subsystem is treated as a single optimization unit, with the goal of minimizing the reactive power loss of each subsystem. Parallel optimization algorithms are used to perform parallel and independent calculations on each subsystem, resulting in parallel optimization calculations for each subsystem.

[0023] Based on the parallel optimization calculation results of each subsystem, calculate remedial measures to improve the voltage stability of that subsystem;

[0024] The remedial measures for improving the voltage stability of each subsystem are combined into a single remedial measure for the power system.

[0025] Optionally, before the step of treating each subsystem as a single optimization unit, minimizing the reactive power loss of each subsystem as the optimization objective, and performing parallel optimization calculations on each subsystem independently and in parallel using a parallel optimization algorithm to obtain the parallel optimization calculation results for each subsystem, the method further includes:

[0026] Set the voltage amplitude of each subsystem to the default value.

[0027] Optionally, the step of treating each subsystem as a single optimization unit, minimizing the reactive power loss of each subsystem as the optimization objective, and using a parallel optimization algorithm to perform parallel and independent calculations on each subsystem to obtain the parallel optimization calculation results for each subsystem includes:

[0028] Each subsystem is treated as a single optimization unit, with the optimization objective being to minimize the reactive power loss of each subsystem. The power transmission of the transmission lines of each subsystem is simulated by virtual generators or virtual loads. The parallel optimization calculations of each subsystem are performed independently to obtain the parallel optimization calculation results of each subsystem, so as to keep the power transmission of the transmission lines of each subsystem constant or as a variable during the parallel optimization process.

[0029] Optionally, the method further includes:

[0030] The overlapping inconsistencies between the various subsystems are resolved by using pre-defined auxiliary problem principles.

[0031] Optionally, performing the remedial measures on the power system to improve the voltage stability of the power system includes:

[0032] Perform corresponding remedial measures on each subsystem to obtain the optimization result of that subsystem;

[0033] By merging the optimization results of each subsystem, the state of the power system is updated to improve the voltage stability of the power system.

[0034] Optionally, after inputting the real-time data into the voltage stability evaluation model, the method further includes:

[0035] Real-time monitoring of the voltage stability index and the angle stability index of the power system;

[0036] When the voltage stability index is below the third critical value, the step of identifying all weak nodes of the power system based on the voltage stability index and the angle stability index is performed.

[0037] A voltage stability enhancement device for a power system, comprising:

[0038] The model building unit is used to build a voltage stability evaluation model for the power system.

[0039] A real-time data acquisition unit is used to acquire real-time data of the power system through a phasor measurement unit.

[0040] An index calculation unit is used to input the real-time data into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angle stability index of the power system.

[0041] A weak node identification unit is used to identify all weak nodes of the power system based on the voltage stability index and the angle stability index.

[0042] The remedial measures calculation unit is used to calculate remedial measures for the power system based on each weak node using a parallel optimization algorithm;

[0043] The remedial action execution unit is used to perform the remedial action on the power system to improve the voltage stability of the power system.

[0044] Optionally, the weak node identification unit includes:

[0045] The weak node identification subunit is used in the power system to identify nodes that exhibit abnormal voltage collapse when the voltage stability index is lower than a first preset threshold or the angle stability index is lower than a second preset threshold.

[0046] Optionally, the index calculation unit includes:

[0047] The voltage stability index calculation unit is used to input the real-time data into the voltage stability evaluation model so that the voltage stability evaluation model constructs a Jacobian matrix based on the real-time data, and calculates the voltage stability index of the power system from the inverse and determinant of the Jacobian matrix.

[0048] An angle stability index calculation unit is used to transform the Jacobian matrix to calculate the angle stability index of the power system based on the parameters of the power system and the transformed Jacobian matrix.

[0049] Optionally, the remedial measure calculation unit includes:

[0050] The subsystem decomposition unit is used to decompose the power system into multiple subsystems based on each weak node using the Newton-Raphson algorithm, and the subsystems are interconnected.

[0051] An optimization unit is used to treat each subsystem as a single optimization unit, with the goal of minimizing the reactive power loss of each subsystem. Parallel optimization algorithms are used to perform parallel and independent calculations on each subsystem, and the parallel optimization calculation results of each subsystem are obtained.

[0052] The subsystem remedial measures calculation unit is used to calculate remedial measures to improve the voltage stability of each subsystem based on the parallel optimization calculation results of each subsystem.

[0053] The remedial measures merging unit is used to merge the remedial measures of each subsystem to improve its voltage stability as a remedial measure to remedy the power system.

[0054] Optionally, the device may also include:

[0055] The voltage amplitude setting unit is used to set the voltage amplitude of each subsystem to a default value before the parallel optimization calculation results of each subsystem are obtained by using each subsystem as a single optimization unit and minimizing the reactive power loss of each subsystem as the optimization objective, and by performing parallel optimization calculations on each subsystem independently and in parallel through a parallel optimization algorithm.

[0056] Optionally, the optimization unit includes:

[0057] The optimization sub-unit is used to treat each subsystem as a single optimization unit, with the optimization objective of minimizing the reactive power loss of each subsystem. It simulates the power transmission of the transmission lines of each subsystem through virtual generators or virtual loads, and performs parallel and independent calculations on each subsystem to obtain the parallel optimization calculation results of each subsystem. This ensures that the power transmission of the transmission lines of each subsystem remains constant or is treated as a variable during the parallel optimization process.

[0058] Optionally, the device may also include:

[0059] The subsystem overlap and inconsistency resolution unit is used to resolve overlap and inconsistency between various subsystems through preset auxiliary problem principles.

[0060] Optionally, the remedial action execution unit is configured to:

[0061] The subsystem remedial action execution unit is used to execute the corresponding remedial action for each subsystem and obtain the optimization result of that subsystem.

[0062] The power system update unit is used to update the state of the power system by merging the optimization results of various subsystems, so as to improve the voltage stability of the power system.

[0063] Optionally, the device may also include:

[0064] The monitoring unit is used to monitor the voltage stability index and the angle stability index of the power system in real time after the real-time data is input into the voltage stability evaluation model.

[0065] The trigger execution unit is used to execute the weak node identification unit when the voltage stability index is lower than the third critical value.

[0066] By employing the above technical solution, this application establishes a voltage stability assessment model for the power system. Real-time data of the power system is collected through a phasor measurement unit and input into the voltage stability assessment model to calculate the voltage stability index and angular stability index of the power system. Based on these indices, all weak points in the power system are identified. Based on each weak point, a parallel optimization algorithm is used to calculate remedial measures to improve the voltage stability of the power system. Therefore, the voltage stability index and angular stability index provide a faster and more accurate voltage stability assessment. Utilizing a parallel optimization algorithm to calculate remedial measures reduces optimization computation time, thereby enabling rapid and accurate voltage stability monitoring and the development of remedial measures, effectively improving the voltage stability of the power system. Attached Figure Description

[0067] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0068] Figure 1 This is a schematic diagram of a process for improving the voltage stability of a power system, provided in an embodiment of this application.

[0069] Figure 2 A flowchart illustrating the implementation of remedial measures using a parallel optimization algorithm, provided in an embodiment of this application;

[0070] Figure 3 This is a schematic diagram illustrating the parallel optimization computation process of multiple subsystems provided in an embodiment of this application.

[0071] Figure 4This is a schematic diagram of a device structure for improving the voltage stability of a power system, provided as an embodiment of this application. Detailed Implementation

[0072] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0073] The proposed solution can be implemented based on a terminal with data processing capabilities, such as a computer, server, or cloud platform.

[0074] Next, combined Figure 1 The voltage stability improvement method for power systems described in this application may include the following steps:

[0075] Step S110: Establish a voltage stability assessment model for the power system.

[0076] Specifically, this model can be built using historical data collected from the power system by a phasor measurement unit (PMU). The model can accept data collected by the PMU as input and calculate the output voltage stability index (QV) and angle stability index (γ).

[0077] The voltage stability index (QV) describes the voltage stability of a power system; a higher QV indicates stronger voltage stability, and vice versa. The angular stability index (γ) describes the phase angle stability of a power system; a higher γ indicates stronger phase angle stability, and vice versa.

[0078] Step S120: Collect real-time data of the power system through the phasor measurement unit.

[0079] Specifically, the PMU can access system signals through voltage and current transformers, perform filtering, amplification, and other conditioning on the signals, and use a clock synchronized with GPS and other systems for synchronous sampling. After sampling, the signals are converted from analog to digital and calculated using algorithms such as Discrete Fourier Transform. Finally, the phasor data is stored and transmitted to the master station system through a communication network. The master station system monitors and analyzes the data for power system dispatch control, fault diagnosis, and other purposes. It can also make control decisions based on the analysis results to ensure the safe and stable operation of the power system.

[0080] Step S130: Input the real-time data into the voltage stability evaluation model so that the voltage stability evaluation model can calculate the voltage stability index and angle stability index of the power system.

[0081] Specifically, the voltage stability assessment model can calculate QV and γ based on real-time data of the power system collected by the PMU.

[0082] Step S140: Identify all weak points in the power system based on the voltage stability index and the angle stability index.

[0083] Specifically, a weak node can be defined as the node in a power system that first experiences a problem during a voltage collapse.

[0084] Step S150: Based on each weak node, calculate remedial measures to remedy the power system using a parallel optimization algorithm.

[0085] Specifically, the power system can be decomposed into multiple subsystems, and then parallel optimization algorithms can be applied to each subsystem for independent optimization calculations.

[0086] Understandably, when performing parallel optimization calculations on multiple subsystems, the optimization calculation time can be reduced, thereby enabling rapid and accurate monitoring of voltage stability and the development of remedial measures.

[0087] Remedial measures may include adjusting the reactive power output of the generator, changing the position of the transformer taps, etc.

[0088] Step S160: Perform the remedial measures on the power system to improve the voltage stability of the power system.

[0089] The voltage stability improvement method for power systems provided in this embodiment establishes a voltage stability assessment model for the power system. Real-time data of the power system is collected through a phasor measurement unit and input into the voltage stability assessment model to calculate the voltage stability index and angular stability index of the power system. Based on the voltage stability index and angular stability index, all weak nodes in the power system are identified. Based on each weak node, a parallel optimization algorithm is used to calculate remedial measures to improve the voltage stability of the power system. Therefore, the voltage stability index and angular stability index provide a faster and more accurate voltage stability assessment. Using a parallel optimization algorithm to calculate remedial measures reduces the optimization calculation time, thereby enabling rapid and accurate voltage stability monitoring and the determination of remedial measures, effectively improving the voltage stability of the power system.

[0090] In some embodiments of this application, the process of identifying all weak nodes of the power system based on the voltage stability index and the angle stability index in step S140 described above is introduced. This process may include:

[0091] In the power system, nodes that exhibit abnormal voltage collapse when the voltage stability index is lower than a first preset threshold or the angle stability index is lower than a second preset threshold are identified as weak nodes.

[0092] Specifically, the first preset threshold value can represent the minimum critical value for maintaining voltage stability in a power system. When the voltage stability index is below this value, it indicates that the voltage of the power system is unstable. The second preset threshold value can represent the minimum critical value for maintaining voltage phase angle stability in a power system. When the phase angle stability index is below this value, it indicates that the voltage phase angle of the power system is unstable. It can be understood that a weak node can represent the node in the power system that first experiences a problem during a voltage collapse. Therefore, when at least one of the above conditions occurs in a power system, the node exhibiting anomalies due to voltage collapse can be identified as a weak node.

[0093] In some embodiments of this application, the process of step S130 above, which involves inputting the real-time data into the voltage stability assessment model to enable the voltage stability assessment model to calculate the voltage stability index and angle stability index of the power system, is described. This process may include:

[0094] S1301. Input the real-time data into the voltage stability evaluation model so that the voltage stability evaluation model constructs a Jacobian matrix based on the real-time data, and calculates the voltage stability index of the power system from the inverse and determinant of the Jacobian matrix.

[0095] Specifically, the construction of the Jacobian matrix can be adjusted according to the characteristics of the power system.

[0096] S1302. Transform the Jacobian matrix to calculate the angular stability index of the power system based on the parameters of the power system and the transformed Jacobian matrix.

[0097] In some embodiments of this application, the process of calculating remedial measures for the power system based on each weak node using a parallel optimization algorithm in step S150 is described, such as... Figure 2 As shown, the process may include:

[0098] Step S1501: Based on each weak node, the power system is decomposed into multiple subsystems using the Newton-Raphson algorithm.

[0099] The various subsystems are interconnected.

[0100] Step S1502: Taking each subsystem as a single optimization unit, with the goal of minimizing the reactive power loss of each subsystem, the parallel optimization algorithm is used to perform parallel and independent calculations on each subsystem to obtain the parallel optimization calculation results of each subsystem.

[0101] Before performing parallel optimization on each subsystem, the voltage amplitude of each subsystem can be set to the default value.

[0102] Specifically, because multiple subsystems perform parallel optimization calculations, each subsystem can be optimized by its corresponding optimization algorithm execution module, such as... Figure 3 As shown. Parallel optimization algorithms can include using virtual generators or virtual loads to simulate the power transmission of transmission lines, keeping the power transmission of the transmission lines constant during the optimization process or adjusting it as a variable. Therefore, the parallel optimization process can be:

[0103] Each subsystem is treated as a single optimization unit, with the optimization objective being to minimize the reactive power loss of each subsystem. The power transmission of the transmission lines of each subsystem is simulated by virtual generators or virtual loads. The parallel optimization calculations of each subsystem are performed independently to obtain the parallel optimization calculation results of each subsystem, so as to keep the power transmission of the transmission lines of each subsystem constant or as a variable during the parallel optimization process.

[0104] Understandably, unlike traditional optimization objective functions, the objective of parallel optimization computation is to minimize the reactive power loss of the system, which helps to increase the voltage stability margin and thus improve the power system's resistance to voltage collapse.

[0105] In addition, during the parallel optimization calculation of each subsystem, the overlapping inconsistencies between the subsystems can be resolved through the pre-defined auxiliary problem principles.

[0106] Step S1503: Based on the parallel optimization calculation results of each subsystem, calculate remedial measures to improve the voltage stability of that subsystem.

[0107] Step S1504: Combine the remedial measures for improving the voltage stability of each subsystem into a remedial measure for the power system.

[0108] This demonstrates that by applying parallel optimization algorithms to power systems, weak points in the power grid can be quickly identified and remedial measures calculated, allowing action to be taken before voltage stability issues arise, thereby improving the operational safety of the power system.

[0109] In some embodiments of this application, the process of performing the remedial measures on the power system in step S160 above to improve the voltage stability of the power system is described, and this process may include:

[0110] S1. Perform corresponding remedial measures on each subsystem to obtain the optimization result of that subsystem.

[0111] It is understandable that after decomposing the power system into multiple subsystems and optimizing each one independently, the remedial measures corresponding to each subsystem can be implemented within the subsystem itself, thereby obtaining the optimization results of the subsystem.

[0112] S2. By merging the optimization results of each subsystem, the state of the power system is updated to improve the voltage stability of the power system.

[0113] Understandably, after all subsystems have been optimized through their respective remedial measures, the state update of the power system shows that the voltage stability of the power system has been improved because each subsystem of the power system has been optimized in terms of voltage stability index and angle stability index.

[0114] To enable more real-time identification of power system voltage stability, and to obtain the power system's voltage stability index and angular stability index in real time for faster response, some embodiments of this application, after inputting the real-time data into the voltage stability evaluation model as mentioned in the foregoing embodiments, may include:

[0115] S1. Monitor the voltage stability index and angle stability index of the power system in real time.

[0116] Specifically, this monitoring module is compatible with power grid monitoring and control systems, thus adapting to power systems of different sizes and complexities, and has good scalability.

[0117] S2. When the voltage stability index is lower than the third critical value, perform step S140 as mentioned in the previous embodiment, which is to identify all weak nodes of the power system based on the voltage stability index and the angle stability index.

[0118] The apparatus for improving the voltage stability of a power system provided in the embodiments of this application will be described below. The apparatus for improving the voltage stability of a power system described below can be referred to in correspondence with the method for improving the voltage stability of a power system described above.

[0119] See Figure 4 , Figure 4This is a schematic diagram of a device structure for improving the voltage stability of a power system, as disclosed in an embodiment of this application.

[0120] like Figure 4 As shown, the device may include:

[0121] Model building unit 11 is used to build a voltage stability evaluation model for the power system.

[0122] Real-time data acquisition unit 12 is used to acquire real-time data of the power system through phasor measurement unit;

[0123] The index calculation unit 13 is used to input the real-time data into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angle stability index of the power system.

[0124] The weak node identification unit 14 is used to identify all weak nodes of the power system based on the voltage stability index and the angle stability index.

[0125] The remedial measure calculation unit 15 is used to calculate remedial measures to remedy the power system based on each weak node using a parallel optimization algorithm.

[0126] The remedial action execution unit 16 is used to perform the remedial action on the power system to improve the voltage stability of the power system.

[0127] Optionally, the weak node identification unit includes:

[0128] The weak node identification subunit is used in the power system to identify nodes that exhibit abnormal voltage collapse when the voltage stability index is lower than a first preset threshold or the angle stability index is lower than a second preset threshold.

[0129] Optionally, the index calculation unit includes:

[0130] The voltage stability index calculation unit is used to input the real-time data into the voltage stability evaluation model so that the voltage stability evaluation model constructs a Jacobian matrix based on the real-time data, and calculates the voltage stability index of the power system from the inverse and determinant of the Jacobian matrix.

[0131] An angle stability index calculation unit is used to transform the Jacobian matrix to calculate the angle stability index of the power system based on the parameters of the power system and the transformed Jacobian matrix.

[0132] Optionally, the remedial measure calculation unit includes:

[0133] The subsystem decomposition unit is used to decompose the power system into multiple subsystems based on each weak node using the Newton-Raphson algorithm, and the subsystems are interconnected.

[0134] An optimization unit is used to treat each subsystem as a single optimization unit, with the goal of minimizing the reactive power loss of each subsystem. Parallel optimization algorithms are used to perform parallel and independent calculations on each subsystem, and the parallel optimization calculation results of each subsystem are obtained.

[0135] The subsystem remedial measures calculation unit is used to calculate remedial measures to improve the voltage stability of each subsystem based on the parallel optimization calculation results of each subsystem.

[0136] The remedial measures merging unit is used to merge the remedial measures of each subsystem to improve its voltage stability as a remedial measure to remedy the power system.

[0137] Optionally, the device may also include:

[0138] The voltage amplitude setting unit is used to set the voltage amplitude of each subsystem to a default value before the parallel optimization calculation results of each subsystem are obtained by using each subsystem as a single optimization unit and minimizing the reactive power loss of each subsystem as the optimization objective, and by performing parallel optimization calculations on each subsystem independently and in parallel through a parallel optimization algorithm.

[0139] Optionally, the optimization unit includes:

[0140] The optimization sub-unit is used to treat each subsystem as a single optimization unit, with the optimization objective of minimizing the reactive power loss of each subsystem. It simulates the power transmission of the transmission lines of each subsystem through virtual generators or virtual loads, and performs parallel and independent calculations on each subsystem to obtain the parallel optimization calculation results of each subsystem. This ensures that the power transmission of the transmission lines of each subsystem remains constant or is treated as a variable during the parallel optimization process.

[0141] Optionally, the device may also include:

[0142] The subsystem overlap and inconsistency resolution unit is used to resolve overlap and inconsistency between various subsystems through preset auxiliary problem principles.

[0143] Optionally, the remedial action execution unit is configured to:

[0144] The subsystem remedial action execution unit is used to execute the corresponding remedial action for each subsystem and obtain the optimization result of that subsystem.

[0145] The power system update unit is used to update the state of the power system by merging the optimization results of various subsystems, so as to improve the voltage stability of the power system.

[0146] Optionally, the device may also include:

[0147] The monitoring unit is used to monitor the voltage stability index and the angle stability index of the power system in real time after the real-time data is input into the voltage stability evaluation model.

[0148] The trigger execution unit is used to execute the weak node identification unit 14 when the voltage stability index is lower than the third critical value.

[0149] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0150] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0151] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for improving the voltage stability of a power system, characterized in that, include: Establish a voltage stability assessment model for power systems; Real-time data of the power system is acquired through a phasor measurement unit; The real-time data is input into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angle stability index of the power system. Based on the voltage stability index and the angle stability index, identify all weak points in the power system; Based on each weak node, remedial measures to remedy the power system are calculated using a parallel optimization algorithm. The remedial measures are performed on the power system to improve the voltage stability of the power system; The remedial measures for the power system, calculated using a parallel optimization algorithm based on each weak node, include: Based on each weak node, the power system is decomposed into multiple subsystems using the Newton-Raphson algorithm, and the subsystems are interconnected. Each subsystem is treated as a single optimization unit, with the goal of minimizing the reactive power loss of each subsystem. Parallel optimization algorithms are used to perform parallel and independent calculations on each subsystem, resulting in parallel optimization calculations for each subsystem. Based on the parallel optimization calculation results of each subsystem, calculate remedial measures to improve the voltage stability of that subsystem; The remedial measures for improving the voltage stability of each subsystem are combined into a remedial measure for the power system. The optimization process, which treats each subsystem as a single optimization unit and aims to minimize the reactive power loss of each subsystem, employs a parallel optimization algorithm to perform independent parallel calculations on each subsystem, yielding the parallel optimization results for each subsystem, including: Each subsystem is treated as a single optimization unit, with the optimization objective being to minimize the reactive power loss of each subsystem. The power transmission of the transmission lines of each subsystem is simulated by virtual generators or virtual loads. The parallel optimization calculations of each subsystem are performed independently to obtain the parallel optimization calculation results of each subsystem, so as to keep the power transmission of the transmission lines of each subsystem constant or as a variable during the parallel optimization process.

2. The method according to claim 1, characterized in that, Based on the voltage stability index and the angle stability index, all weak points in the power system are identified, including: In the power system, nodes that exhibit abnormal voltage collapse when the voltage stability index is lower than a first preset threshold or the angle stability index is lower than a second preset threshold are identified as weak nodes.

3. The method according to claim 1, characterized in that, The real-time data is input into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angular stability index of the power system, including: The real-time data is input into the voltage stability assessment model so that the voltage stability assessment model constructs a Jacobian matrix based on the real-time data, and calculates the voltage stability index of the power system from the inverse and determinant of the Jacobian matrix. The Jacobian matrix is ​​transformed to calculate the angular stability index of the power system based on the parameters of the power system and the transformed Jacobian matrix.

4. The method according to claim 1, characterized in that, Before the step of treating each subsystem as a single optimization unit, minimizing the reactive power loss of each subsystem as the optimization objective, and performing parallel optimization calculations on each subsystem independently and in parallel using a parallel optimization algorithm to obtain the parallel optimization calculation results for each subsystem, the following steps are also included: Set the voltage amplitude of each subsystem to the default value.

5. The method according to claim 1, characterized in that, Also includes: The overlapping inconsistencies between the various subsystems are resolved by using pre-defined auxiliary problem principles.

6. The method according to claim 1, characterized in that, Performing the remedial measures on the power system to improve the voltage stability of the power system includes: Perform corresponding remedial measures on each subsystem to obtain the optimization result of that subsystem; By merging the optimization results of each subsystem, the state of the power system is updated to improve the voltage stability of the power system.

7. The method according to any one of claims 1-6, characterized in that, After inputting the real-time data into the voltage stability evaluation model, the method further includes: Real-time monitoring of the voltage stability index and the angle stability index of the power system; When the voltage stability index is below the third critical value, the step of identifying all weak nodes of the power system based on the voltage stability index and the angle stability index is performed.

8. A voltage stability improvement device for a power system, characterized in that, The voltage stability improvement method for a power system as described in claim 1, wherein the voltage stability improvement device comprises: The model building unit is used to build a voltage stability evaluation model for the power system. A real-time data acquisition unit is used to acquire real-time data of the power system through a phasor measurement unit. An index calculation unit is used to input the real-time data into the voltage stability assessment model so that the voltage stability assessment model can calculate the voltage stability index and angle stability index of the power system. A weak node identification unit is used to identify all weak nodes of the power system based on the voltage stability index and the angle stability index. The remedial measures calculation unit is used to calculate remedial measures for the power system based on each weak node using a parallel optimization algorithm; The remedial action execution unit is used to perform the remedial action on the power system to improve the voltage stability of the power system.

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