Method and system for identifying high-frequency harmonic propagation path and key equipment of power system

Abstract

The invention discloses a method and system for identifying a high-frequency harmonic propagation path and key equipment of a power system, and belongs to the technical field of power quality and simulation analysis of the power system, and the method comprises the steps: constructing a high-frequency harmonic propagation potential index based on a power grid topological structure, a node power flow and a branch impedance parameter, and identifying a suspected high-frequency harmonic propagation candidate region; carrying out equivalent modeling on the non-suspected high-frequency harmonic propagation candidate area by adopting a multi-port Thevenin equivalent method; establishing a high-frequency harmonic simulation model based on each electrical device, performing time domain simulation, performing frequency domain analysis on a power signal of each electrical device, identifying a high-frequency harmonic propagation path, and performing visual display; and calculating the harmonic voltage amplitude variation of the head and tail end nodes of each branch in the propagation path, and identifying the key equipment by quantitatively evaluating the influence degree of each electrical equipment on the high-frequency harmonic propagation, thereby solving the problems that the high-frequency harmonic propagation analysis in the prior art depends on whole-network simulation, the calculated amount is large and the key equipment identification capability is lacked.

Description

A method and system for identifying high-frequency harmonic propagation paths and key equipment in power systems Technical Field

[0001] This invention relates to a method and system for identifying high-frequency harmonic propagation paths and key equipment in power systems, belonging to the field of power system power quality and simulation analysis technology. Background Technology

[0002] With the large-scale integration of new energy sources and power electronic equipment into the power grid, the high-frequency characteristics of the system are becoming increasingly complex. Various converters, parallel compensation devices, and filter units may generate abundant high-frequency harmonic components under different operating conditions. These harmonics couple with each other in the power grid and propagate along branches, easily leading to problems such as voltage distortion, equipment overheating, and resonant amplification. Existing research and monitoring methods mainly focus on the analysis of harmonic generation mechanisms and the design of suppression measures, such as optimizing control loops or adding filters to reduce the output of high-frequency harmonic sources. However, in complex power grid environments, the propagation law of high-frequency harmonics depends not only on the intensity of the harmonic source but also on the combined influence of multiple factors such as network topology, node impedance characteristics, and power flow distribution. Even weak harmonic sources may amplify through electrical coupling in specific frequency bands.

[0003] Traditional methods often rely on network-wide electromagnetic transient simulation to study propagation characteristics. However, these methods are computationally intensive, involve complex modeling, and have low analysis efficiency, making them difficult to apply in engineering. Furthermore, existing impedance methods or frequency domain analysis methods cannot analyze the propagation trend of high-frequency harmonics across the entire network. Even after the propagation path is determined, there is a lack of quantitative assessment methods for the impact of various devices on harmonic propagation, making it difficult to identify key amplifying devices during propagation. Therefore, there is an urgent need to propose a method for identifying high-frequency harmonic propagation paths and key devices in power systems. This method would identify the propagation paths of high-frequency harmonics through time-domain simulation of a local power grid. Based on this, the changes in harmonic voltage amplitude during propagation would be used to locate key devices, providing a basis for formulating high-frequency harmonic suppression measures. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for identifying the propagation path of high-frequency harmonics and key equipment in a power system. By performing time-domain simulation of a local power grid, the propagation path of high-frequency harmonics is identified, and the location of key equipment is achieved by measuring the changes in harmonic voltage amplitude during the propagation process. This solves the problems of existing technologies where high-frequency harmonic propagation analysis relies on full-network simulation, involves large computational loads, and lacks the ability to identify key equipment.

[0005] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.

[0006] In a first aspect, the present invention provides a method for identifying high-frequency harmonic propagation paths and key equipment in a power system, comprising:

[0007] High-frequency harmonic propagation potential indices are constructed based on power grid topology, node power flow, and branch impedance parameters, and suspected candidate regions for high-frequency harmonic propagation are identified.

[0008] The multi-port Thevenin equivalent method was used to perform equivalent modeling on candidate regions for non-suspected high-frequency harmonic propagation.

[0009] A high-frequency harmonic simulation model was established for each power device in the suspected high-frequency harmonic propagation candidate region and time-domain simulation was performed. By performing frequency domain analysis on the power signals of each electrical device, the high-frequency harmonic propagation path was identified and visualized.

[0010] Calculate the changes in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path, and identify key equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

[0011] Furthermore, based on the power grid topology, node power flow, and branch impedance parameters, a high-frequency harmonic propagation potential index is constructed, and suspected candidate regions for high-frequency harmonic propagation are identified, including:

[0012] For each node in the power grid, perform the following steps:

[0013] Obtain the power flow and branch impedance parameters of each node in the power grid, as well as the topology of the power grid;

[0014] Calculate the node excitation potential term based on the power grid topology and power flow calculation results of each node;

[0015] Calculate the node impedance transmission potential term based on the power grid topology and branch impedance parameters;

[0016] The node excitation potential term and the node impedance transmission potential term are normalized, and the high-frequency harmonic propagation potential index is calculated based on the normalized excitation potential term and the normalized impedance transmission potential term.

[0017] Based on the high-frequency harmonic propagation potential index of all nodes, suspected high-frequency harmonic propagation candidate regions are identified according to the judgment rules for suspected high-frequency harmonic propagation candidate regions.

[0018] The rule for determining the suspected high-frequency harmonic propagation candidate region is as follows:

[0019] If the high-frequency harmonic propagation potential index value of the current node exceeds a set multiple of the average high-frequency harmonic propagation potential index value of all nodes in the power grid, then the current node and its connected branches are determined to be suspected high-frequency harmonic propagation candidate areas.

[0020] Furthermore, the node excitation potential term is expressed as:

[0021] ;

[0022] In the formula, Represents a node Incentive potential items, Represents a node The meritorious trend, Represents a node The maximum power flow value within its adjacent node set, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The difference, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The maximum value of the difference Indicates harmonic source To the node electrical distance, Indicates harmonic source Maximum electrical distance to any node;

[0023] The node impedance transmission potential term is expressed as:

[0024] ;

[0025] In the formula, Represents a node The impedance transfer potential term, Represents a node and nodes The impedance amplitude of the branch in which it is located, This represents the baseline value for branch impedance, taking the maximum branch impedance value. Represents an exponential function. , Representing nodes respectively and nodes Thevenin equivalent impedance magnitude, This represents the baseline value of the node's equivalent impedance, taking the maximum value of the node's equivalent impedance. This represents the penalty coefficient for matching discrepancies. The default value is 0.5.

[0026] Furthermore, the normalized excitation potential term and the normalized impedance transfer potential term are respectively expressed as:

[0027] ;

[0028] In the formula, Represents the normalized node Incentive potential items, Represents the normalized node The impedance transfer potential term, This represents the function that takes the maximum value.

[0029] The high-frequency harmonic propagation potential index is expressed as follows:

[0030] ;

[0031] In the formula, Represents a node High-frequency harmonic propagation potential index, This represents the weighting coefficient used to balance the effects of tidal currents. This represents the weighting factor used to balance the effects of impedance, satisfying... , , The value is calculated based on the subjective and objective weighting method;

[0032] The rule for determining the candidate region of suspected high-frequency harmonic propagation is expressed as follows:

[0033] ;

[0034] In the formula, This indicates the set multiplier, which is an empirical threshold coefficient with a value of 0.01. This represents the average value of the high-frequency harmonic propagation potential index for all nodes in the power grid.

[0035] Furthermore, the multi-port Thevenin equivalent method is used to perform equivalent modeling on the non-suspected high-frequency harmonic propagation candidate regions, including:

[0036] The boundary nodes of the suspected high-frequency harmonic propagation candidate region are used as multi-port interfaces.

[0037] Based on the power flow and impedance parameters of the non-suspected high-frequency harmonic propagation candidate region, the equivalent voltage source and equivalent impedance model of the multi-port are established to replace the non-suspected high-frequency harmonic propagation candidate region for equivalent modeling.

[0038] Furthermore, by performing frequency domain analysis on the power signals of various electrical devices, the propagation paths of high-frequency harmonics are identified and visualized, including:

[0039] Time-domain simulation was performed on the established high-frequency harmonic simulation model. Fast Fourier Transform (FFT) analysis results of each electrical device were obtained by performing FFT on the power signals of each electrical device.

[0040] Based on the fast Fourier transform analysis results of each electrical device, candidate harmonic components are obtained by judging through harmonic component identification criteria.

[0041] Candidate harmonic components with amplitudes greater than or equal to the threshold value are retained as the final harmonic components;

[0042] To obtain the final harmonic components and the electrical equipment containing the harmonic components;

[0043] Based on the topology of the power grid and the electrical equipment containing harmonic components, the propagation paths of each harmonic component are identified, and the propagation paths of each harmonic component are visualized in a graph structure.

[0044] Furthermore, the harmonic component identification criterion is expressed as follows:

[0045] ;

[0046] In the formula, Indicates the first The first electrical device One frequency, The power frequency of the grid is 50Hz. For the first The allowable frequency deviation for the subharmonics is 0.5 Hz.

[0047] Furthermore, the changes in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path are calculated. Key equipment is identified by quantitatively assessing the impact of each electrical device on high-frequency harmonic propagation, including:

[0048] Based on the high-frequency harmonic propagation path, the change in harmonic voltage amplitude at the first and last nodes of each branch is calculated.

[0049] If the change in harmonic voltage amplitude at the beginning and end nodes of the current branch is greater than the preset threshold for the change in harmonic voltage amplitude, then the power equipment corresponding to the current branch is identified as a key device that has a significant impact on the propagation of high-frequency harmonics.

[0050] Furthermore, the change in the harmonic voltage amplitude is expressed as:

[0051] ;

[0052] In the formula, For the first The change in the amplitude of the second harmonic voltage For nodes The Second harmonic amplitude; For nodes The Second harmonic amplitude.

[0053] In a second aspect, the present invention provides a power system high-frequency harmonic propagation path and key equipment identification system, used to implement the power system high-frequency harmonic propagation path and key equipment identification method described in the first aspect, comprising:

[0054] The candidate region identification module is used to construct high-frequency harmonic propagation potential indices based on the power grid topology, node power flow, and branch impedance parameters, and to identify suspected high-frequency harmonic propagation candidate regions.

[0055] The non-candidate region modeling module is used to perform equivalent modeling of non-suspected high-frequency harmonic propagation candidate regions using the multi-port Thevenin equivalent method.

[0056] The propagation path visualization module is used to establish high-frequency harmonic simulation models and perform time-domain simulations for each power device based on suspected high-frequency harmonic propagation candidate areas. By performing frequency domain analysis on the power signals of each electrical device, the high-frequency harmonic propagation path is identified and visualized.

[0057] The critical equipment identification module is used to calculate the change in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path, and to identify critical equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

[0058] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0059] 1. This invention constructs a high-frequency harmonic propagation potential index and identifies potential candidate regions for high-frequency harmonic propagation. By combining the multi-port Thevenin equivalent method to perform equivalent modeling on non-candidate regions, it can achieve rapid and accurate positioning of the high-frequency harmonic propagation range and simplify the processing of complex power grid models. This effectively improves the efficiency and pertinence of high-frequency harmonic propagation path analysis and provides reliable preliminary support for subsequent visualization of high-frequency harmonic propagation paths and identification of key equipment based on time-domain simulation and frequency-domain analysis. It solves the problems of existing technologies where high-frequency harmonic propagation analysis relies on full-network simulation, has a large computational load, and lacks the ability to identify key equipment.

[0060] 2. This invention constructs a high-frequency harmonic propagation potential index based on the power grid topology, node power flow, and branch impedance parameters. Combined with the normalization of node excitation potential and node impedance transmission potential terms and the judgment rules for suspected high-frequency harmonic propagation candidate regions, it can accurately identify high-frequency harmonic propagation candidate regions, reduce the amount of invalid calculations for non-candidate regions, and achieve rapid and accurate positioning of the propagation range, providing efficient pre-screening for subsequent time-domain simulation and frequency-domain analysis.

[0061] 3. This invention uses the multi-port Thevenin equivalent method to perform equivalent modeling on non-suspected high-frequency harmonic propagation candidate regions, simplifying them into equivalent voltage source and equivalent impedance models. While preserving the electrical characteristics of boundary nodes, it reduces system complexity and effectively improves the efficiency of high-frequency harmonic propagation path analysis, making it particularly suitable for rapid analysis scenarios in large-scale power grids.

[0062] 4. Based on the time-domain simulation and frequency-domain analysis of the high-frequency harmonic simulation model, this invention combines harmonic component identification criteria and harmonic voltage amplitude variation calculation to intuitively and visually display the high-frequency harmonic propagation path. By quantitatively assessing the impact of each electrical device on harmonic propagation, it can accurately identify key equipment and provide a basis for harmonic control and equipment optimization in power grid operation and maintenance. Attached Figure Description

[0063] Figure 1 is a flowchart illustrating a method for identifying high-frequency harmonic propagation paths and key equipment in a power system, provided by an embodiment of the present invention. Detailed Implementation

[0064] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0065] Example 1

[0066] As shown in Figure 1, this embodiment introduces a method for identifying high-frequency harmonic propagation paths and key equipment in power systems, including:

[0067] Step 1: Construct a high-frequency harmonic propagation potential index based on the power grid topology, node power flow, and branch impedance parameters, and identify potential candidate regions for high-frequency harmonic propagation.

[0068] This invention constructs a high-frequency harmonic propagation potential index based on power grid topology, node power flow, and branch impedance parameters. By normalizing the node excitation potential term and the node impedance transmission potential term, and using the judgment rules for suspected high-frequency harmonic propagation candidate regions, it can accurately screen out suspected high-frequency harmonic propagation candidate regions, achieve rapid positioning of the propagation range, reduce the amount of invalid calculations for non-suspected high-frequency harmonic propagation candidate regions, provide an efficient preliminary screening basis for subsequent high-frequency harmonic propagation path analysis, and improve the overall analysis efficiency and pertinence.

[0069] Step 2: Use the multi-port Thevenin equivalent method to perform equivalent modeling on the non-suspected high-frequency harmonic propagation candidate regions.

[0070] This invention employs the multi-port Thevenin equivalent method to perform equivalent modeling on non-suspected high-frequency harmonic propagation candidate regions, simplifying them into equivalent voltage source and equivalent impedance models. While preserving the electrical characteristics of boundary nodes, it reduces system complexity and effectively improves the efficiency of high-frequency harmonic propagation path analysis, making it particularly suitable for rapid analysis scenarios in large-scale power grids.

[0071] Step 3: Establish high-frequency harmonic simulation models for each power device in the suspected high-frequency harmonic propagation candidate region and perform time-domain simulation. By performing frequency domain analysis on the power signals of each electrical device, identify the high-frequency harmonic propagation path and visualize it.

[0072] This invention establishes a high-frequency harmonic simulation model for each power device in a suspected high-frequency harmonic propagation candidate region and performs time-domain simulation. It achieves frequency-domain analysis of power signals through fast Fourier transform, filters effective harmonic components by combining harmonic component identification criteria, identifies high-frequency harmonic propagation paths, and visualizes them in a graph structure, intuitively presenting the harmonic propagation trajectory and providing an intuitive path basis for harmonic management in power grid operation and maintenance.

[0073] Step 4: Calculate the change in harmonic voltage amplitude at the first and last nodes of each branch in the high-frequency harmonic propagation path, and identify key equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

[0074] This invention calculates the changes in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path and performs quantitative evaluation by combining preset thresholds. This can accurately identify key equipment that has a significant impact on high-frequency harmonic propagation, providing quantitative data support for power grid equipment optimization and harmonic mitigation strategy formulation, and improving the pertinence and effectiveness of mitigation measures.

[0075] Example 2

[0076] Based on the same inventive concept as Embodiment 1, this embodiment describes the implementation steps of a method for identifying high-frequency harmonic propagation paths and key equipment in power systems:

[0077] Step 1: Construct a high-frequency harmonic propagation potential index based on the power grid topology, node power flow and branch impedance parameters, and identify suspected high-frequency harmonic propagation candidate regions.

[0078] Step 1.1: Perform the following steps for each node in the power grid.

[0079] Step 1.1.1: Obtain the power flow and branch impedance parameters of each node in the power grid and the topology of the power grid.

[0080] Step 1.1.2: Calculate the node excitation potential terms based on the power grid topology and the power flow calculation results of each node.

[0081] In this embodiment, the node excitation potential term is represented as:

[0082] ;

[0083] In the formula, Represents a node Incentive potential items, Represents a node The meritorious trend, Represents a node The maximum power flow value within its adjacent node set, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The difference, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The maximum value of the difference Indicates harmonic source To the node electrical distance, Indicates harmonic source The maximum electrical distance to any node.

[0084] Step 1.1.3: Calculate the node impedance transmission potential term based on the power grid topology and branch impedance parameters.

[0085] In this embodiment, the node impedance transmission potential term is expressed as:

[0086] ;

[0087] In the formula, Represents a node The impedance transfer potential term, Represents a node and nodes The impedance amplitude of the branch in which it is located, This represents the baseline value for branch impedance, taking the maximum branch impedance value. Represents an exponential function. , Representing nodes respectively and nodes Thevenin equivalent impedance magnitude, This represents the baseline value of the node's equivalent impedance, taking the maximum value of the node's equivalent impedance. This represents the penalty coefficient for matching discrepancies. The default value is 0.5.

[0088] Step 1.1.4: Normalize the node excitation potential term and the node impedance transmission potential term, and calculate the high-frequency harmonic propagation potential index based on the normalized excitation potential term and the normalized impedance transmission potential term.

[0089] In this embodiment, the normalized excitation potential term and the normalized impedance transfer potential term are respectively expressed as:

[0090] ;

[0091] In the formula, Represents the normalized node Incentive potential items, Represents the normalized node The impedance transfer potential term, This represents the function that takes the maximum value.

[0092] In this embodiment, the high-frequency harmonic propagation potential index is expressed as:

[0093] ;

[0094] In the formula, Represents a node High-frequency harmonic propagation potential index, This represents the weighting coefficient used to balance the effects of tidal currents. This represents the weighting factor used to balance the effects of impedance, satisfying... , , The value is calculated based on the subjective and objective weighting method.

[0095] Step 1.2: Based on the high-frequency harmonic propagation potential index of all nodes, identify the suspected high-frequency harmonic propagation candidate regions according to the judgment rules for suspected high-frequency harmonic propagation candidate regions.

[0096] In this embodiment, the rule for determining the suspected high-frequency harmonic propagation candidate region is as follows:

[0097] If the high-frequency harmonic propagation potential index value of the current node exceeds a set multiple of the average high-frequency harmonic propagation potential index value of all nodes in the power grid, then the current node and its connected branches are determined to be suspected high-frequency harmonic propagation candidate areas.

[0098] In this embodiment, the rule for determining the suspected high-frequency harmonic propagation candidate region is expressed as follows:

[0099] ;

[0100] In the formula, This indicates the set multiplier, which is an empirical threshold coefficient with a value of 0.01. This represents the average value of the high-frequency harmonic propagation potential index for all nodes in the power grid.

[0101] Step 2: Use the multi-port Thevenin equivalent method to perform equivalent modeling on the candidate regions for non-suspected high-frequency harmonic propagation.

[0102] Step 2.1: Use the boundary nodes of the suspected high-frequency harmonic propagation candidate region as multi-port interfaces.

[0103] Step 2.2: Based on the power flow and impedance parameters of the non-suspected high-frequency harmonic propagation candidate region, establish the equivalent voltage source and equivalent impedance model of the multi-port, replace the non-suspected high-frequency harmonic propagation candidate region, and perform equivalent modeling.

[0104] Step 3: Establish high-frequency harmonic simulation models for each power device in the suspected high-frequency harmonic propagation candidate region and perform time-domain simulation. By performing frequency domain analysis on the power signals of each electrical device, identify the high-frequency harmonic propagation path and visualize it.

[0105] Step 3.1: Establish high-frequency harmonic simulation models for each power device in the suspected high-frequency harmonic propagation candidate region.

[0106] Step 3.2: Perform time-domain simulation on the established high-frequency harmonic simulation model. By performing fast Fourier transform on the power signals of each electrical device, obtain the fast Fourier transform analysis results of each electrical device.

[0107] Step 3.3: Based on the Fast Fourier Transform analysis results of each electrical device, candidate harmonic components are obtained by judging through the harmonic component identification criteria.

[0108] In this embodiment, the harmonic component identification criterion is expressed as:

[0109] ;

[0110] In the formula, Indicates the first The first electrical device One frequency, The power frequency of the grid is 50Hz. For the first The allowable frequency deviation for the subharmonics is 0.5 Hz.

[0111] Step 3.4: Retain candidate harmonic components with amplitudes greater than or equal to the threshold value as the final harmonic components.

[0112] Step 3.5: Obtain the final harmonic components and the electrical equipment containing the harmonic components.

[0113] Step 3.6: Identify the propagation path of each harmonic component based on the topology of the power grid and the electrical equipment containing harmonic components, and visualize the propagation path of each harmonic component in a graph structure.

[0114] Step 4: Calculate the change in harmonic voltage amplitude at the first and last nodes of each branch in the high-frequency harmonic propagation path, and identify key equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

[0115] Step 4.1: Based on the high-frequency harmonic propagation path, calculate the change in harmonic voltage amplitude at the first and last nodes of each branch.

[0116] In this embodiment, the change in the harmonic voltage amplitude is expressed as:

[0117] ;

[0118] In the formula, For the first The change in the amplitude of the second harmonic voltage For nodes The Second harmonic amplitude; For nodes The Second harmonic amplitude.

[0119] Step 4.2: If the change in harmonic voltage amplitude at the first and last nodes of the current branch is greater than the preset threshold for the change in harmonic voltage amplitude, then the power equipment corresponding to the current branch is identified as a key device that has a significant impact on the propagation of high-frequency harmonics.

[0120] Example 3

[0121] Based on the same inventive concept as other embodiments, this embodiment introduces a power system high-frequency harmonic propagation path and key equipment identification system, used to implement the power system high-frequency harmonic propagation path and key equipment identification method described in Embodiment 1 or 2, including:

[0122] The candidate region identification module is used to construct high-frequency harmonic propagation potential indices based on the power grid topology, node power flow, and branch impedance parameters, and to identify suspected high-frequency harmonic propagation candidate regions.

[0123] The non-candidate region modeling module is used to perform equivalent modeling of non-suspected high-frequency harmonic propagation candidate regions using the multi-port Thevenin equivalent method.

[0124] The propagation path visualization module is used to establish high-frequency harmonic simulation models and perform time-domain simulations for each power device based on suspected high-frequency harmonic propagation candidate areas. By performing frequency domain analysis on the power signals of each electrical device, the high-frequency harmonic propagation path is identified and visualized.

[0125] The critical equipment identification module is used to calculate the change in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path, and to identify critical equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

[0126] The specific functions of each module described above are explained in the relevant content of Embodiment 1 or 2, and will not be repeated here.

[0127] Example 4

[0128] Based on the same inventive concept as other embodiments, this embodiment describes a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the methods of Embodiment 1 or 2 described above.

[0129] Example 5

[0130] Based on the same inventive concept as other embodiments, this embodiment introduces a computer program product, including computer instructions that, when executed by a processor, implement the steps of the methods described in Embodiment 1 or 2 above.

[0131] In summary, this invention constructs a high-frequency harmonic propagation potential index and identifies potential candidate regions for high-frequency harmonic propagation. By combining the multi-port Thevenin equivalent method to perform equivalent modeling on non-candidate regions, it can achieve rapid and accurate positioning of the high-frequency harmonic propagation range and simplify the processing of complex power grid models. This effectively improves the efficiency and relevance of high-frequency harmonic propagation path analysis, and provides reliable preliminary support for subsequent visualization of high-frequency harmonic propagation paths and identification of key equipment based on time-domain simulation and frequency-domain analysis. It solves the problems of existing technologies where high-frequency harmonic propagation analysis relies on full-network simulation, involves large computational loads, and lacks the ability to identify key equipment.

[0132] This invention constructs a high-frequency harmonic propagation potential index based on power grid topology, node power flow, and branch impedance parameters. By combining the normalization of node excitation potential and node impedance transmission potential terms with the judgment rules for suspected high-frequency harmonic propagation candidate regions, it can accurately identify high-frequency harmonic propagation candidate regions, reduce the amount of invalid computation in non-candidate regions, and achieve rapid and accurate positioning of the propagation range, providing efficient pre-screening for subsequent time-domain simulation and frequency-domain analysis.

[0133] This invention employs the multi-port Thevenin equivalent method to perform equivalent modeling of non-suspected high-frequency harmonic propagation candidate regions, simplifying complex structures such as external networks into equivalent voltage sources and equivalent impedance models. While preserving the electrical characteristics of boundary nodes, it reduces system complexity and effectively improves the efficiency of high-frequency harmonic propagation path analysis, making it particularly suitable for rapid analysis scenarios in large-scale power grids.

[0134] This invention is based on time-domain simulation and frequency-domain analysis of a high-frequency harmonic simulation model. Combined with harmonic component identification criteria and calculation of harmonic voltage amplitude changes, it can intuitively and visually display the propagation path of high-frequency harmonics. Furthermore, by quantitatively assessing the impact of each electrical device on harmonic propagation, it can accurately identify key equipment and provide a basis for harmonic control and equipment optimization in power grid operation and maintenance.

[0135] 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 embodied 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.

[0136] 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, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0137] 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 that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0138] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0139] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for identifying high-frequency harmonic propagation paths and key equipment in a power system, characterized in that, include: High-frequency harmonic propagation potential indices are constructed based on power grid topology, node power flow, and branch impedance parameters, and suspected candidate regions for high-frequency harmonic propagation are identified. The multi-port Thevenin equivalent method is used to perform equivalent modeling on non-suspected high-frequency harmonic propagation candidate regions; high-frequency harmonic simulation models are established for each power device based on the suspected high-frequency harmonic propagation candidate regions and time-domain simulation is performed; by performing frequency domain analysis on the power signals of each electrical device, the high-frequency harmonic propagation path is identified and visualized. Calculate the changes in harmonic voltage amplitude at the beginning and end nodes of each branch in the high-frequency harmonic propagation path, and identify key equipment by quantitatively assessing the impact of each electrical device on the high-frequency harmonic propagation.

2. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 1, characterized in that, A high-frequency harmonic propagation potential index is constructed based on the power grid topology, node power flow, and branch impedance parameters, and suspected high-frequency harmonic propagation candidate regions are identified. This includes: for each node in the power grid, the following steps are performed: obtaining the power flow, branch impedance parameters, and topology of each node; calculating the node excitation potential term based on the power grid topology and the power flow calculation results of each node; calculating the node impedance transmission potential term based on the power grid topology and branch impedance parameters; normalizing the node excitation potential term and the node impedance transmission potential term, and calculating the high-frequency harmonic propagation potential index based on the normalized excitation potential term and the normalized impedance transmission potential term; identifying suspected high-frequency harmonic propagation candidate regions based on the high-frequency harmonic propagation potential index of all nodes according to the suspected high-frequency harmonic propagation candidate region determination rules; wherein, the suspected high-frequency harmonic propagation candidate region determination rules are: if the high-frequency harmonic propagation potential index value of the current node exceeds a set multiple of the average high-frequency harmonic propagation potential index of all nodes in the power grid, then the current node and its connected branches are determined to be suspected high-frequency harmonic propagation candidate regions.

3. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 2, characterized in that, The node excitation potential term is represented as follows: In the formula, Represents a node Incentive potential items, Represents a node The meritorious trend, Represents a node The maximum power flow value within its adjacent node set, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The difference, Represents a node voltage phase angle Voltage phase angle with the node where the high-frequency harmonic source is located The maximum value of the difference Indicates harmonic source To the node electrical distance, Indicates harmonic source The maximum electrical distance to any node; the node impedance transmission potential term is expressed as: In the formula, Represents a node The impedance transfer potential term, Represents a node and nodes The impedance amplitude of the branch in which it is located, This represents the baseline value for branch impedance, taking the maximum branch impedance value. Represents an exponential function. 、 Representing nodes respectively and nodes Thevenin equivalent impedance magnitude, This represents the baseline value of the node's equivalent impedance, taking the maximum value of the node's equivalent impedance. This represents the penalty coefficient for matching discrepancies. The default value is 0.

5.

4. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 3, characterized in that, The normalized excitation potential term and the normalized impedance transport potential term are respectively expressed as: In the formula, Represents the normalized node Incentive potential items, Represents the normalized node The impedance transfer potential term, The function represents the maximum value; the high-frequency harmonic propagation potential index is expressed as: In the formula, Represents a node High-frequency harmonic propagation potential index, This represents the weighting coefficient used to balance the effects of tidal currents. This represents the weighting factor used to balance the effects of impedance, satisfying... ， 、 The value is calculated based on the subjective and objective weighting method; the rule for determining the suspected high-frequency harmonic propagation candidate region is expressed as follows: In the formula, This indicates the set multiplier, which is an empirical threshold coefficient with a value of 0.

01. This represents the average value of the high-frequency harmonic propagation potential index for all nodes in the power grid.

5. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 1, characterized in that, The multi-port Thevenin equivalent method is used to perform equivalent modeling of non-suspected high-frequency harmonic propagation candidate regions, including: using the boundary nodes of the suspected high-frequency harmonic propagation candidate regions as multi-port interfaces; and establishing the equivalent voltage source and equivalent impedance model of the multi-port based on the power flow and impedance parameters of the non-suspected high-frequency harmonic propagation candidate regions to replace the non-suspected high-frequency harmonic propagation candidate regions for equivalent modeling.

6. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 1, characterized in that, By performing frequency domain analysis on the power signals of various electrical devices, the propagation paths of high-frequency harmonics are identified and visualized. This includes: performing time-domain simulation on the established high-frequency harmonic simulation model; obtaining the Fast Fourier Transform (FFT) analysis results for each electrical device by performing FFT on the power signals of each device; determining candidate harmonic components based on the FFT analysis results of each device using harmonic component identification criteria; retaining candidate harmonic components with amplitudes greater than or equal to a threshold value as the final harmonic components; obtaining the final harmonic components and the electrical devices containing harmonic components; identifying the propagation paths of each harmonic component based on the power grid topology and the electrical devices containing harmonic components, and visualizing the propagation paths of each harmonic component in a graph structure.

7. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 6, characterized in that, The harmonic component identification criterion is expressed as follows: In the formula, Indicates the first The first electrical device One frequency, The power frequency of the grid is 50Hz. For the first The allowable frequency deviation for the subharmonics is 0.5 Hz.

8. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 1, characterized in that, The calculation of harmonic voltage amplitude changes at the beginning and end nodes of each branch in the high-frequency harmonic propagation path is used to identify key equipment by quantitatively assessing the impact of each electrical device on high-frequency harmonic propagation. This includes: calculating the harmonic voltage amplitude changes at the beginning and end nodes of each branch based on the high-frequency harmonic propagation path; if the harmonic voltage amplitude changes at the beginning and end nodes of the current branch are greater than a preset threshold for harmonic voltage amplitude changes, then the electrical equipment corresponding to the current branch is identified as a key device that has a significant impact on high-frequency harmonic propagation.

9. The method for identifying high-frequency harmonic propagation paths and key equipment in power systems according to claim 8, characterized in that, The change in the amplitude of the harmonic voltage is expressed as follows: In the formula, For the first The change in the amplitude of the second harmonic voltage For nodes The Second harmonic amplitude; For nodes The Second harmonic amplitude.

10. A power system high-frequency harmonic propagation path and key equipment identification system, characterized in that, The method for identifying high-frequency harmonic propagation paths and key equipment in a power system according to any one of claims 1-9 comprises: a candidate region identification module, used to construct a high-frequency harmonic propagation potential index based on the power grid topology, node power flow, and branch impedance parameters, and to identify suspected high-frequency harmonic propagation candidate regions; a non-candidate region modeling module, used to perform equivalent modeling of non-suspected high-frequency harmonic propagation candidate regions using the multi-port Thevenin equivalent method; a propagation path visualization module, used to establish high-frequency harmonic simulation models for each power device in the suspected high-frequency harmonic propagation candidate regions and perform time-domain simulation, identify high-frequency harmonic propagation paths and visualize them by performing frequency-domain analysis on the power signals of each electrical device; and a key equipment identification module, used to calculate the harmonic voltage amplitude changes at the first and last nodes of each branch in the high-frequency harmonic propagation path, and identify key equipment by quantitatively assessing the degree of influence of each electrical device on high-frequency harmonic propagation.

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