A harmonic tracing method and device based on power grid topology, a terminal and a medium

Abstract

The application discloses a kind of based on power grid topology harmonic tracing method, device, terminal and medium, in which a kind of based on power grid topology harmonic tracing method includes: acquisition multi-source data, track harmonic reverse propagation path and screen key node;Based on key node acquisition equipment characteristic, waveform characteristic and timing characteristic, construct harmonic source feature library, and the harmonic power characteristic of key node is normalized conversion;Using harmonic source feature library calculates the matching degree of key node and target type equipment in feature library, according to matching degree confirms harmonic source node and potential harmonic source node;Based on normalized value calculation contribution degree, determine target harmonic propagation path and the target harmonic source on path;The application accurately tracks harmonic propagation path by double criterion, filters key node to reduce invalid data processing;Meanwhile, by hierarchical calculation contribution degree, the influence weight of each node is clear, effectively improve the tracing accuracy, reduce power grid harmonic risk.

Description

Technical Field

[0001] This invention relates to the technical field of harmonic control, and in particular to a harmonic source tracing method, device, terminal and medium based on power grid topology. Background Technology

[0002] With the widespread application of power electronic equipment and the large-scale grid connection of new energy sources, harmonic pollution in power systems has become increasingly prominent. Harmonics not only cause overheating and losses in equipment such as transformers and motors, but also interfere with the normal operation of relay protection devices, seriously threatening the safety and stability of the power grid. Therefore, accurately locating harmonic sources and quantifying their contribution has become a key prerequisite for harmonic mitigation.

[0003] In existing technologies, such as the harmonic extraction method based on an improved orthogonal phase-locked loop (PLL) proposed in patent application number CN202210674999.2, although harmonic extraction is achieved by constructing a power supply network topology map, converting per-unit values, and calculating the admittance matrix, the following limitations still exist: First, the power grid topology map constructed by this method has a fixed structure and cannot respond to changes in the power grid topology in real time, resulting in a disconnect between the topology and the actual operating state, and a decrease in the accuracy of source tracing; Second, the observability dependence is too high, as this method only relies on basic electrical quantities such as voltage, current, and power, resulting in insufficient data dimensions; Third, the calculation method based on a fixed admittance matrix and voltage vector does not consider the propagation attenuation characteristics of harmonics at different frequencies, resulting in low accuracy in allocating the contribution of multiple harmonic sources in the coexisting scenario. Summary of the Invention

[0004] The purpose of this invention is to provide a harmonic source tracing method based on power grid topology to solve the problems of static topology, single data dimension, and large contribution error in the prior art.

[0005] To address the aforementioned technical problems, this invention provides the following technical solution: collecting multi-source data, tracing harmonic back propagation paths, and screening key nodes; constructing a harmonic source feature library and converting the harmonic power characteristics of key nodes to per-unit values; using the harmonic source feature library to calculate the matching degree between key nodes and target type equipment, and confirming harmonic source nodes and potential harmonic source nodes based on the matching degree; calculating the contribution based on per-unit values ​​to determine the target harmonic propagation path and the target harmonic sources on the path.

[0006] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, the following steps are taken: Monitoring points and analysis nodes are selected based on the power grid topology; the phase difference of the nth harmonic between monitoring point i and its neighboring node j is calculated based on multi-source data; if the phase difference is greater than 120°, the neighboring node j is initially determined to be an upstream candidate node of monitoring point i; the multi-source data includes harmonic voltage phase, load power, harmonic distortion rate, transient harmonic peak value, and equipment parameters; if a transformer exists between the neighboring node j and the upstream extension node z, the phase abrupt change rate is calculated; if the phase abrupt change rate is less than 10%, the upstream extension node z is the upstream node of the neighboring node j; upstream nodes are recursively traced until any of the following conditions are met and tracing stops: no further upstream nodes; phase difference ≤ 60°; transient peak value multiple greater than 5; a harmonic reverse propagation path is formed after tracing stops.

[0007] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, the selection of key nodes includes: based on the tracing results of the harmonic back propagation path, marking nodes that simultaneously meet any of the following conditions as key nodes: harmonic voltage distortion rate greater than 3%; the node is connected to power electronic equipment with a rated power greater than 100 kVA; and the load fluctuation amplitude is greater than 20%.

[0008] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, the construction of the harmonic source feature library includes: collecting harmonic source feature data of key nodes, wherein the harmonic source feature data includes equipment features, waveform features, timing features, and harmonic power features; establishing a mapping based on the harmonic source feature data to construct the harmonic source feature library; calculating the deviation rate between the harmonic source feature data of each cycle and the harmonic source feature library; if the deviation rate is greater than 3%, updating the data in the basic library and re-associating the harmonic frequencies, thereby updating the harmonic source feature library.

[0009] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, the identification of harmonic source nodes and potential harmonic source nodes includes: calculating the feature similarity between key nodes and target type equipment t, including equipment feature similarity, waveform feature similarity, and time series feature similarity; and calculating the total matching degree M based on the feature similarity. q, t If M q, t If M > 0.7, the critical node q is determined to be a harmonic source node; if M < 0.5, the critical node q is determined to be a harmonic source node. q, t If M ≤ 0.7, the critical node q is determined to be a potential harmonic source node; if M q, t If ≤0.5, the critical node q is determined to be a non-harmonic source node.

[0010] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, the calculation of contribution includes:

[0011] The amplitude coupling influence coefficient of the m-th harmonic on the n-th harmonic is calculated based on the harmonic source feature library. :

[0012] ;

[0013] In the formula, The device switching frequency associated with the nth harmonic. The device switching frequency associated with the m-th harmonic. The reference value for the switching frequency. The peak factor of the nth harmonic is... is the peak factor of the m-th harmonic;

[0014] Based on amplitude coupling influence coefficient Calculate the total coupling contribution of the nth harmonic. :

[0015] ;

[0016] In the formula, To measure the voltage distortion rate of the nth harmonic at the monitoring point, To monitor the voltage distortion rate of the k-th harmonic at the monitoring point, The amplitude coupling effect coefficient of the m-th harmonic on the k-th harmonic;

[0017] Calculate the path attenuation correction factor based on the real-time temperature of the line.

[0018] The dynamic contribution of the p-th harmonic back propagation path to the n-th harmonic at the monitoring point is calculated based on the path attenuation correction factor. :

[0019] ;

[0020] In the formula, Let n be the per-unit value of the nth harmonic voltage at the potential source node at the end of the p-th harmonic back propagation path. Let n be the per-unit value of the static total impedance of the nth harmonic along the p-th harmonic's reverse propagation path. is the path attenuation correction coefficient of the nth harmonic for the back propagation path of the pth harmonic; P is the total number of harmonic back propagation paths;

[0021] filter The harmonic reverse propagation path is taken as the target harmonic propagation path. The characteristic coupling contribution of each harmonic source node on the target harmonic propagation path to the nth harmonic of the monitoring point is calculated by combining the per-unit value. The harmonic source node with a characteristic coupling contribution greater than 70% is selected as the target harmonic source.

[0022] As a preferred embodiment of the harmonic source tracing method based on power grid topology described in this invention, it further includes: dividing the governance priority according to the characteristic coupling contribution degree and matching the corresponding governance measures.

[0023] The present invention also provides a harmonic source tracing device based on power grid topology, used to implement the harmonic source tracing method based on power grid topology as described in any of the preceding claims. The harmonic source tracing device based on power grid topology includes: a screening module configured to collect multi-source data, trace the harmonic back propagation path, and screen key nodes; a feature acquisition module configured to construct a harmonic source feature library and perform per-unit value conversion on the harmonic power characteristics of key nodes; a harmonic source node acquisition module configured to calculate the matching degree between key nodes and target type equipment using the harmonic source feature library, and confirm harmonic source nodes and potential harmonic source nodes based on the matching degree; and a harmonic source tracing module configured to calculate the contribution based on per-unit values, and determine the target harmonic propagation path and the target harmonic sources on the path.

[0024] The present invention also provides a terminal device, comprising:

[0025] One or more processors;

[0026] A memory, coupled to the processor, for storing one or more programs;

[0027] When the one or more programs are executed by the one or more processors, the one or more processors implement the harmonic source tracing method based on the power grid topology as described in any of the preceding claims.

[0028] The present invention also provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the harmonic source tracing method based on power grid topology as described in any of the preceding claims.

[0029] The beneficial effects of this invention are as follows: This invention accurately tracks the harmonic propagation path through dual criteria, filters key nodes to reduce invalid data processing; establishes a dynamic feature library to adapt to changes in equipment parameters, improving the accuracy of harmonic source matching; and clarifies the influence weight of each node through hierarchical calculation of contribution, effectively improving the source tracing accuracy and reducing the risk of power grid harmonics. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0031] Figure 1This is a schematic diagram of the process for harmonic source tracing based on power grid topology as described in the first embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the process for constructing a harmonic source feature library according to the first embodiment of the present invention. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0036] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0037] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Example 1

[0040] Reference Figures 1-2 This is the first embodiment of the present invention, which provides a harmonic source tracing method based on power grid topology, including:

[0041] S1: Collect multi-source data, trace the harmonic back propagation path, and screen key nodes.

[0042] Multi-source data includes harmonic voltage phase, load power, harmonic distortion rate, transient harmonic peak value, and equipment parameters. Specifically, harmonic voltage phase at each node is acquired through a synchronous phasor measurement unit; real-time load power at each node is acquired through a data acquisition terminal; harmonic distortion rate at each node is acquired through a harmonic analyzer; transient harmonic peak value is acquired through a transient recorder, and the transient peak value multiple is calculated; equipment parameter data includes transformer model between nodes, line impedance, and rated power of the equipment.

[0043] Based on the power grid topology, monitoring points and analysis nodes (adjacent nodes, upstream extension nodes, etc.) are selected. The phase difference of the nth harmonic between monitoring point i and adjacent node j is calculated based on multi-source data. :

[0044] ;

[0045] In the formula, Let n be the phase of the nth harmonic voltage at node i. The phase of the nth harmonic voltage at node j;

[0046] If the phase difference is greater than 120°, then node j is preliminarily determined to be an upstream candidate node of monitoring point i;

[0047] Preferably, the present invention can quickly filter out possible upstream nodes from multiple adjacent nodes through simple phase difference calculation, thereby reducing the number of nodes to be verified and improving the filtering efficiency.

[0048] Furthermore, for the selected upstream candidate node j, verify whether its upstream extension node x has a phase change due to the device, so as to avoid misjudging a node that appears to be upstream due to the device phase shift as a true upstream node.

[0049] Specifically, if there is a transformer between the adjacent node j and the upstream extended node x, calculate the mutation rate of the nth harmonic between nodes j and x. :

[0050] ;

[0051] In the formula, Let n be the phase of the nth harmonic voltage at node x. This represents the theoretical phase offset between node j and node x.

[0052] like If the percentage is less than 10%, then node x is the upstream node of node j, forming the path segment i←j←x; otherwise, node x is determined to be a non-upstream node.

[0053] Furthermore, recursively trace the upstream nodes until any of the following conditions are met, at which point the tracing stops:

[0054] There are no upstream nodes (e.g., node x has no other upstream nodes in the topology);

[0055] When the phase difference is ≤60°, the harmonics attenuate significantly after propagating through the line, and the impact on the monitoring point is ≤5%.

[0056] Transient peak value A value greater than 5 indicates the presence of abnormal transient disturbances (such as equipment short circuits or impulsive load startup). Transient signals can interfere with the stability of harmonic source tracing, requiring priority to troubleshoot the fault. The current path tracing should be stopped, and data should be recollected after the fault is resolved. In the formula, I... tr For transient harmonic peak value, I rate This is the rated current value;

[0057] After tracking stops, a harmonic reverse propagation path is formed.

[0058] Furthermore, based on the tracing results of the harmonic back propagation path, nodes that simultaneously meet any of the following conditions are marked as key nodes:

[0059] Harmonic voltage distortion rate greater than 3%;

[0060] Power electronic equipment with a rated power greater than 100 kVA (such as photovoltaic inverters, frequency converters, etc.) connected to the node have a harmonic emission rate greater than 60%, making them the main harmonic source.

[0061] When the load fluctuation is greater than 20%, the equipment harmonic current fluctuation is greater than 30%, which can easily aggravate the harmonic pollution of the power grid.

[0062] S2: Based on the characteristics of key node acquisition equipment, waveform characteristics, and time sequence characteristics, construct a harmonic source feature library, and perform per-unit value conversion on the harmonic power characteristics of key nodes.

[0063] Reference Figure 2 Harmonic source characteristic data of key nodes are collected. The harmonic source characteristic data includes equipment characteristics, waveform characteristics, timing characteristics, and harmonic power characteristics. Equipment characteristics include switching frequency, modulation ratio, topology, etc. Waveform characteristics include peak factor of harmonics, distribution ratio of harmonic order, etc. Timing characteristics include daily fluctuation amplitude of harmonic current, monthly average value of harmonic power, etc. Harmonic power characteristics include active power and reactive power of each harmonic.

[0064] Based on harmonic source feature data, a mapping is established between equipment type, harmonic source features, and harmonic frequencies to construct a harmonic source feature library, including a primary index, a secondary index, and a data layer. The primary index establishes unique identifiers based on the target equipment type classification. Each identifier corresponds to a type of equipment in the power grid with similar harmonic emission patterns, serving as the top-level classification entry point for the feature library. The secondary index further subdivides each equipment type according to its dominant harmonic frequencies. Since the dominant harmonic frequencies differ significantly between different equipment types, this layer can filter out the key interference frequencies for the corresponding equipment type, avoiding meaningless storage of full-frequency features. The data layer stores harmonic source feature data for the scenario at the intersection of equipment type and harmonic frequency, covering four main categories: equipment features, waveform features, time-series features, and harmonic power features.

[0065] Calculate the characteristic data of the harmonic source for each cycle. Deviation rate between the source and the harmonic source feature library :

[0066] ;

[0067] In the formula, Harmonic source feature data from the harmonic source feature library;

[0068] If the deviation rate is greater than 3%, the data in the base library is updated, and the harmonic frequencies are re-associated, thereby updating the harmonic source feature library.

[0069] Furthermore, the per-unit value conversion is performed on the nth harmonic power characteristics of the key nodes:

[0070] ;

[0071] In the formula, Let n be the per-unit value of the power of the nth harmonic. The actual active power of the nth harmonic. For switching frequency, The actual impedance of the nth harmonic of the line connected to the node. The rated power of the node, The reference impedance is the nth harmonic.

[0072] S3: Calculate the matching degree between key nodes and target type equipment using the harmonic source feature library, and confirm the harmonic source nodes and potential harmonic source nodes based on the matching degree.

[0073] Calculate the feature similarity between the key node q and the target type device t, including device feature similarity, waveform feature similarity, and time series feature similarity; specifically:

[0074] Device feature similarity :

[0075] ;

[0076] In the formula, The switching frequency of the key node q-connected device. The switching frequency of the target type device t. The modulation ratio of the key node q-access device. The modulation ratio of the target type device t. For device topology matching coefficients;

[0077] Waveform feature similarity :

[0078] ;

[0079] In the formula, Let be the peak factor of the nth harmonic at the critical node q. The peak factor of the nth harmonic of the target type device t. is the harmonic waveform distortion mode matching coefficient, and n is the harmonic frequency;

[0080] Temporal feature similarity :

[0081] ;

[0082] In the formula, Let be the Pearson correlation coefficient between the nth harmonic active power at critical node q and the real-time load power. Let be the Pearson correlation coefficient between the nth harmonic active power of target type device t and the real-time load power.

[0083] The total matching degree M is calculated based on the feature similarity of the target type device t. q, t :

[0084] ;

[0085] In the formula, The weights for device feature similarity. The weights for waveform feature similarity. The weights for temporal feature similarity.

[0086] If M q, t If the value is greater than 0.7, the critical node q is determined to be a harmonic source node;

[0087] If 0.5 < M q, t If the value is ≤0.7, the critical node q is determined to be a potential harmonic source node;

[0088] If M q, t If ≤0.5, the critical node q is determined to be a non-harmonic source node.

[0089] S4: Calculate the contribution based on the per-unit value to determine the target harmonic propagation path and the target harmonic sources on the path.

[0090] Traditional technical solutions only calculate the contribution of a single frequency, ignoring the coupling effect between multiple harmonics (such as the mutual influence between the 5th and 7th harmonics due to the correlation of equipment switching frequencies). This solution first calculates the coupling contribution of each harmonic frequency to the total harmonic pollution at the monitoring point, and screens the main influencing frequencies to limit the frequency range for subsequent calculations. Specifically, based on the harmonic source feature library, it extracts the multi-frequency harmonic coupling correlation data of key node equipment to calculate the amplitude coupling influence coefficient of the m-th harmonic on the n-th harmonic. :

[0091] ;

[0092] In the formula, The device switching frequency associated with the nth harmonic. The device switching frequency associated with the m-th harmonic. The reference value for the switching frequency. The peak factor of the nth harmonic is... is the peak factor of the m-th harmonic;

[0093] The closer the switching frequencies are and the smaller the difference in peak factors, the stronger the coupling effect is, indicating that the two harmonics are generated by the same device.

[0094] Furthermore, based on the amplitude coupling influence coefficient Calculate the total coupling contribution of the nth harmonic. :

[0095] ;

[0096] In the formula, To measure the voltage distortion rate of the nth harmonic at the monitoring point, To monitor the voltage distortion rate of the k-th harmonic at the monitoring point, The amplitude coupling effect coefficient of the m-th harmonic on the k-th harmonic;

[0097] Will Frequency >20% is considered the main influencing frequency. Subsequent calculations will only focus on the path and node contribution for these frequencies, reducing computational load while taking into account coupling effects.

[0098] Calculate the path attenuation correction factor based on the real-time temperature of the line. ;

[0099] ;

[0100] In the formula, This is the path attenuation correction coefficient for the nth harmonic via the back propagation path of the p-th harmonic, used to optimize the path contribution. The reference temperature for the line. Let be the real-time temperature of the line along the p-th harmonic back propagation path. This is the line aging correction factor for the p-th harmonic reverse propagation path;

[0101] For the main influencing frequencies selected, the dynamic contribution of the p-th harmonic back propagation path to the n-th harmonic at the monitoring point is calculated based on the path attenuation correction coefficient. :

[0102] ;

[0103] In the formula, Let n be the per-unit value of the nth harmonic voltage at the potential source node at the end of the p-th harmonic back propagation path. Let n be the per-unit value of the static total impedance of the nth harmonic along the p-th harmonic's reverse propagation path. is the path attenuation correction coefficient of the nth harmonic for the back propagation path of the pth harmonic; P is the total number of harmonic back propagation paths;

[0104] filter The harmonic back propagation path is used as the target harmonic propagation path. The characteristic coupling contribution of each harmonic source node y on the target harmonic propagation path to the nth harmonic at the monitoring point is calculated by combining the per-unit value. :

[0105] ;

[0106] In the formula, Let be the per-unit value of the nth harmonic power at the harmonic source node y. Let y be the matching degree between the harmonic source node and the target type device t. y is the characteristic coupling factor of the harmonic source node y with respect to the nth harmonic;

[0107] ;

[0108] In the formula, The actual switching frequency of the harmonic source node y device. Let be the standard switching frequency associated with the nth harmonic, and be the actual modulation ratio of the harmonic source node y.

[0109] Harmonic source nodes with a characteristic coupling contribution greater than 70% are selected as target harmonic sources.

[0110] S5: Prioritize governance based on the contribution of feature coupling and match corresponding governance measures.

[0111] Main harmonic source nodes: Hardware-based solutions (filtering, compensation, etc.) are required.

[0112] Secondary harmonic source nodes: Priority software (control strategy adjustment, etc.);

[0113] Potential harmonic source nodes: They will only be included in dynamic monitoring and will not be treated for the time being.

[0114] Example 2

[0115] This invention provides a harmonic source tracing device based on power grid topology, used to implement the steps of the harmonic source tracing method based on power grid topology as described in any of the above embodiments. The harmonic source tracing device based on power grid topology includes:

[0116] The filtering module is configured to collect multi-source data, track the back propagation path of harmonics, and filter key nodes.

[0117] The feature acquisition module is configured to acquire device features, waveform features, and time sequence features based on key nodes, construct a harmonic source feature library, and perform per-unit value conversion on the harmonic power features of key nodes.

[0118] The module for obtaining harmonic source nodes is configured to perform calculations using a harmonic source feature library to determine the matching degree between key nodes and target type devices in the feature library, and to confirm harmonic source nodes and potential harmonic source nodes based on the matching degree.

[0119] The harmonic source tracing module is configured to perform contribution calculations based on per-unit values ​​to determine the target harmonic propagation path and the target harmonic sources on the path.

[0120] Example 3

[0121] This embodiment provides a terminal device, including:

[0122] One or more processors;

[0123] A memory, coupled to the processor, for storing one or more programs;

[0124] When the one or more programs are executed by the one or more processors, the one or more processors implement the harmonic source tracing method based on the power grid topology as described above.

[0125] The processor controls the overall operation of the terminal device to complete all or part of the steps of the aforementioned harmonic source tracing method based on power grid topology. The memory stores various types of data to support the operation of the terminal device. This data may include, for example, instructions for any application or method operating on the terminal device, as well as application-related data. The memory can be implemented using any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0126] The terminal device can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the harmonic source tracing method based on power grid topology as described in any of the above embodiments, and achieve the same technical effect as the above method.

[0127] Example 4

[0128] This embodiment provides a computer-readable storage medium whose program instructions, when executed by a processor, implement the steps of the harmonic source tracing method based on power grid topology as described in any of the above embodiments. For example, the computer-readable storage medium can be the memory including the program instructions, which can be executed by the processor of a terminal device to complete the harmonic source tracing method based on power grid topology as described in any of the above embodiments, and achieve the same technical effect as the above method.

[0129] It should be recognized that embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable storage medium. The method can be implemented using standard programming techniques—including a non-transitory computer-readable storage medium configured with a computer program, wherein such a storage medium causes the computer to operate in a specific and predefined manner—according to the methods and drawings described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Furthermore, for this purpose, the program can run on a programmed application-specific integrated circuit (ASIC).

[0130] Furthermore, the procedures described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by the context. The procedures described herein (or variations and / or combinations thereof) may be executed under the control of one or more computer systems configured with executable instructions, and may be implemented by hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that commonly executes on one or more processors. The computer program comprises a plurality of instructions executable by one or more processors.

[0131] Furthermore, the method can be implemented in any suitable type of computing platform, including but not limited to personal computers, minicomputers, mainframes, workstations, networked or distributed computing environments, standalone or integrated computer platforms, or in communication with charged particle tools or other imaging devices, etc. Aspects of the invention can be implemented as machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and / or write storage medium, RAM, ROM, etc., such that it is readable by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. Furthermore, the machine-readable code, or portions thereof, can be transmitted via wired or wireless networks. The invention described herein includes these and other different types of non-transitory computer-readable storage media when such media comprises instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor. When programmed according to the methods and techniques described herein, the invention also includes the computer itself. A computer program can be applied to input data to perform the functions described herein, thereby transforming the input data to generate output data stored in non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the invention, the converted data represents physical and tangible objects, including specific visual depictions of physical and tangible objects generated on a display.

[0132] As used herein, the terms “component,” “module,” “system,” etc., are intended to refer to a computer-related entity, which may be hardware, firmware, a combination of hardware and software, software, or running software. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a running thread, a program, and / or a computer. As an example, an application running on a computing device and the computing device itself can both be components. One or more components may reside in a running process and / or thread, and components may be located in a single computer and / or distributed among two or more computers. Furthermore, these components are capable of execution from various computer-readable media having various data structures thereon. These components may communicate locally and / or remotely via signals, such as those containing one or more data packets (e.g., data from a component that interacts with a local system, another component in a distributed system, and / or signals that interact with other systems via a network such as the Internet).

[0133] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A harmonic source tracing method based on power grid topology, characterized in that, include: Collect multi-source data, trace the back propagation path of harmonics, and screen key nodes; Construct a harmonic source feature library and perform per-unit value conversion on the harmonic power characteristics of key nodes; The matching degree between key nodes and target type equipment is calculated using a harmonic source feature library, and the harmonic source nodes and potential harmonic source nodes are identified based on the matching degree. The contribution is calculated based on the per-unit value to determine the target harmonic propagation path and the target harmonic sources on the path. The path of harmonic back propagation includes: Based on the power grid topology, monitoring points and analysis nodes are selected. The phase difference of the nth harmonic between monitoring point i and its neighboring node j is calculated based on multi-source data. If the phase difference is greater than 120°, the neighboring node j is initially determined to be an upstream candidate node of monitoring point i. The multi-source data includes harmonic voltage phase, load power, harmonic distortion rate, transient harmonic peak value, and equipment parameters. If there is a transformer between the adjacent node j and the upstream extension node z, calculate the phase mutation rate. If the phase mutation rate is less than 10%, then the upstream extension node z is the upstream node of the adjacent node j. Recursively trace upstream nodes until any of the following conditions are met and tracing stops: no upstream node; phase difference ≤ 60°; transient peak multiple greater than 5. After tracking stops, a harmonic reverse propagation path is formed; The calculation of contribution includes: The amplitude coupling influence coefficient of the m-th harmonic on the n-th harmonic is calculated based on the harmonic source feature library. : ; In the formula, The device switching frequency associated with the nth harmonic. The device switching frequency associated with the m-th harmonic. The reference value for the switching frequency. The peak factor of the nth harmonic is... The peak factor of the m-th harmonic; Based on amplitude coupling influence coefficient Calculate the total coupling contribution of the nth harmonic. : ; In the formula, To measure the voltage distortion rate of the nth harmonic at the monitoring point, To monitor the voltage distortion rate of the k-th harmonic at the monitoring point, The amplitude coupling effect coefficient of the m-th harmonic on the k-th harmonic; Calculate the path attenuation correction factor based on the real-time temperature of the line. The dynamic contribution of the p-th harmonic back propagation path to the n-th harmonic at the monitoring point is calculated based on the path attenuation correction factor. : ; In the formula, Let n be the per-unit value of the nth harmonic voltage at the potential source node at the end of the p-th harmonic back propagation path. Let be the per-unit value of the static total impedance of the nth harmonic along the p-th harmonic's back propagation path. is the path attenuation correction coefficient of the nth harmonic for the p-th harmonic back propagation path; P is the total number of harmonic back propagation paths; filter The harmonic reverse propagation path is taken as the target harmonic propagation path, and the characteristic coupling contribution of each harmonic source node y on the target harmonic propagation path to the nth harmonic at the monitoring point is calculated by combining the per-unit value. : ; In the formula, Let be the per-unit value of the nth harmonic power at the harmonic source node y. Let be the matching degree between the harmonic source node y and the target type device t. Let y be the characteristic coupling factor of the harmonic source node to the nth harmonic; Harmonic source nodes with a characteristic coupling contribution greater than 70% are selected as target harmonic sources.

2. The harmonic source tracing method based on power grid topology as described in claim 1, characterized in that, Key screening nodes include: Based on the tracing results of the harmonic back propagation path, nodes that simultaneously meet any of the following conditions are marked as critical nodes: Harmonic voltage distortion rate greater than 3%; The node connects to power electronic equipment with a rated power greater than 100 kVA; The load fluctuation range is greater than 20%.

3. The harmonic source tracing method based on power grid topology as described in claim 2, characterized in that, The construction of the harmonic source feature library includes: Harmonic source characteristic data of key nodes are collected, including equipment characteristics, waveform characteristics, timing characteristics and harmonic power characteristics; A mapping is established based on harmonic source feature data to construct a harmonic source feature library; Calculate the deviation rate between the harmonic source feature data for each cycle and the harmonic source feature library. If the deviation rate is greater than 3%, update the data in the base library and re-associate the harmonic frequencies, thereby updating the harmonic source feature library.

4. The harmonic source tracing method based on power grid topology as described in claim 3, characterized in that, The identified harmonic source nodes and potential harmonic source nodes include: Calculate the feature similarity between key nodes and target type device t, including device feature similarity, waveform feature similarity, and time series feature similarity; The total matching degree M is calculated based on feature similarity. q, t ; If M q, t If the value is greater than 0.7, the critical node q is determined to be a harmonic source node; If 0.5 < M q, t If the value is ≤0.7, the critical node q is determined to be a potential harmonic source node; If M q, t If ≤0.5, the critical node q is determined to be a non-harmonic source node.

5. The harmonic source tracing method based on power grid topology as described in claim 4, characterized in that, Also includes: Governance priorities are determined based on the contribution of feature coupling, and corresponding governance measures are matched accordingly.

6. A harmonic source tracing device based on power grid topology, used to implement the harmonic source tracing method based on power grid topology as described in any one of claims 1 to 5, characterized in that, The harmonic source tracing device based on power grid topology includes: The filtering module is configured to collect multi-source data, track the back propagation path of harmonics, and filter key nodes. The feature acquisition module is configured to build a harmonic source feature library and perform per-unit conversion on the harmonic power features of key nodes. The module for obtaining harmonic source nodes is configured to perform calculations of the matching degree between key nodes and target type devices using a harmonic source feature library, and to confirm harmonic source nodes and potential harmonic source nodes based on the matching degree. The harmonic source tracing module is configured to perform contribution calculations based on per-unit values ​​to determine the target harmonic propagation path and the target harmonic sources on the path.

7. A terminal device, characterized in that, include: One or more processors; A memory, coupled to the processor, for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the harmonic source tracing method based on power grid topology as described in any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor to implement the harmonic source tracing method based on power grid topology as described in any one of claims 1 to 5.

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