Power system resonance suppression method, device and equipment and storage medium

Abstract

The invention provides a power system resonance suppression method and device, equipment and a storage medium, and relates to the technical field of power quality analysis and control. The method comprises the following steps: acquiring electrical signals of a plurality of nodes in a power system, and identifying a source node which generates harmonic resonance currently and a corresponding resonant frequency based on the electrical signals; a load redistribution scheme is generated with the aim of destroying the resonance condition of the source node, the scheme is used for transferring at least one load under the source node to other nodes so as to change the system impedance of the source node, and the system impedance is equal to the parallel equivalent value of the impedance of all the loads under the source node; a load redistribution scheme is performed to suppress harmonic resonance. Resonance suppression can be realized only by optimizing the existing network load distribution, the system transformation cost is remarkably reduced, the additional operation loss is reduced, the instability risk is controlled, meanwhile, the advantages of rapid response, high adaptability and the like are achieved, and effective technical support is provided for constructing a safe and flexible novel power system.

Description

Technical Field

[0001] This application relates to the field of power quality analysis and control technology, and in particular to a method, device, equipment and storage medium for power system resonance suppression. Background Technology

[0002] In the development of power systems, new energy sources, represented by wind power and photovoltaics, are rapidly being connected to the grid, and the penetration rate of power electronic equipment in the system continues to increase. In distribution networks, a large number of nonlinear loads inject harmonics into the grid, leading to increasingly serious harmonic pollution problems and a sharp increase in the risk of system resonance. When the harmonic frequency coincides with the inherent resonant point of the grid impedance, harmonic resonance will occur, causing abnormal amplification of voltage or current at specific frequencies. This can lead to serious consequences such as insulation flashover of electrical equipment, relay protection malfunction, and voltage transformer burnout, directly threatening the safe and stable operation of the power system and the reliability of power supply. Therefore, how to effectively suppress system resonance has become a key technical challenge to ensure the safe and stable operation of new power systems.

[0003] In related technologies, passive suppression, active mitigation, or system network topology reconfiguration are commonly used to suppress resonance in power systems. Passive suppression schemes reshape the system impedance characteristics by adding passive components such as resistors and reactors at the resonance point to disrupt the resonance condition. Active mitigation schemes inject reverse harmonic current into the system using power electronic converters to dynamically cancel the resonance. System network topology reconfiguration schemes adjust the grid operation mode or connection structure to change system parameters and eliminate resonance. However, these schemes typically rely on hardware modifications or localized control and cannot dynamically adapt to the system impedance changes brought about by the integration of new energy sources into the grid. Summary of the Invention

[0004] This application provides a power system resonance suppression method, apparatus, equipment, and storage medium to improve the problem that related technologies typically rely on hardware modifications or local control, which cannot dynamically adapt to system impedance changes brought about by the grid connection of new energy sources.

[0005] In a first aspect, this application provides a method for suppressing resonance in a power system, comprising:

[0006] Acquire electrical signals from multiple nodes in a power system;

[0007] Based on electrical signals, identify the source nodes and corresponding resonant frequencies of harmonic resonance currently occurring in the power system;

[0008] With the goal of disrupting the resonance condition of the source node, a load redistribution scheme is generated. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of the impedances of all loads under the source node.

[0009] Implement a load redistribution scheme to suppress harmonic resonance.

[0010] In one possible implementation, based on electrical signals, identifying the source nodes and corresponding resonant frequencies of harmonic resonances currently occurring in the power system includes: performing spectral analysis on the electrical signals to obtain harmonic electrical characteristic information of each harmonic at each node, and generating voltage spectra corresponding to each node, wherein the harmonic electrical characteristic information includes voltage amplitude, current amplitude, and phase information; based on the voltage spectra corresponding to each node, identifying and determining frequency points where the voltage amplitude exceeds a preset voltage threshold as suspected resonant frequency points; for each suspected resonant frequency point and its corresponding node, performing impedance amplitude verification and phase analysis verification operations, wherein the impedance amplitude verification operation includes: determining... The process involves determining whether the harmonic impedance at the suspected resonant frequency point is greater than the harmonic impedance at at least one adjacent frequency point of the node at the suspected resonant frequency point. The phase analysis verification operation includes: determining whether the absolute value of the phase difference at the suspected resonant frequency point is less than a preset phase tolerance threshold. The harmonic impedance is determined based on the voltage and current amplitudes at the suspected resonant frequency point, and the phase difference is determined based on the phase information of the harmonic voltage and harmonic current at the suspected resonant frequency point. If the node is at the suspected resonant frequency point and the judgment results of both the impedance amplitude verification operation and the phase analysis verification operation are yes, then the node is determined to be the source node of harmonic resonance, and the suspected resonant frequency point is the corresponding resonant frequency.

[0011] In one possible implementation, spectral analysis of the electrical signal includes: windowing the electrical signal to obtain a windowed signal; and performing a mathematical transformation on the windowed signal to obtain harmonic electrical characteristic information of each harmonic at each node.

[0012] In one possible implementation, the mathematical transformation includes at least one of Fourier transform or wavelet transform.

[0013] In one possible implementation, a load redistribution scheme is generated with the goal of disrupting the resonance condition of the source node. This includes: identifying at least one other node on the same power supply bus as the source node as a collaborative evaluation node; constructing a system resonance risk assessment model based on the network parameters of the source node and the collaborative evaluation node; solving for the corresponding load transfer method with the goal of minimizing the output value of the system resonance risk assessment model; and generating a load redistribution scheme that indicates at least one load under the source node to at least one of the collaborative evaluation nodes based on the solution results.

[0014] In one possible implementation, a system resonance risk assessment model is constructed, including: determining a set of harmonic frequencies requiring resonance risk assessment for the source node and each collaborative assessment node, wherein the set of harmonic frequencies does not include harmonic frequencies that are integer multiples of three; for each node to be assessed among the source node and all collaborative assessment nodes, and for each harmonic frequency in the set of harmonic frequencies corresponding to the node to be assessed, a penalty factor value is assigned to the node to be assessed at the harmonic frequency based on the matching state between the system impedance and the inherent impedance of the capacitor bank at the harmonic frequency after the implementation of the candidate load transfer scheme; wherein, when the system impedance and the inherent impedance of the capacitor bank reach resonance matching, a first value is assigned, otherwise a second value is assigned; the first value is greater than the second value; wherein, the inherent impedance of the capacitor bank includes the inductive reactance of the reactor and the capacitive reactance of the capacitor; and summing all the penalty factor values ​​assigned to the source node and all collaborative assessment nodes at their respective harmonic frequency sets, and using the summation result as the output value of the system resonance risk assessment model.

[0015] In one possible implementation, the corresponding load transfer method is solved by minimizing the output value of the system resonance risk assessment model as the optimization objective. This includes: establishing an optimization problem using the connection relationship of the loads in the source node and all collaborative assessment nodes as decision variables; minimizing the output value of the system resonance risk assessment model as the optimization objective of the optimization problem, and including at least one auxiliary optimization objective or constraint; the auxiliary optimization objective or constraint includes at least one of the following: load balance between nodes, limit on the number of switching operations, and power supply reliability index; solving the optimization problem to obtain a set of load connection relationships as the corresponding load transfer method.

[0016] Secondly, this application provides a power system resonance suppression device, comprising:

[0017] The acquisition module is used to acquire electrical signals from multiple nodes in the power system.

[0018] The identification module is used to identify the source node and corresponding resonant frequency of harmonic resonance in the power system based on electrical signals.

[0019] The load redistribution scheme generation module is used to generate a load redistribution scheme with the goal of disrupting the resonance condition of the source node. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of all load impedances under the source node.

[0020] The execution module is used to implement the load redistribution scheme to suppress harmonic resonance.

[0021] Thirdly, this application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0022] Memory is used to store instructions executed by the computer;

[0023] A processor for executing computer-executable instructions stored in memory to implement any of the methods of the first aspect.

[0024] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed, are used to implement the method of any one of the first aspects.

[0025] Fifthly, this application provides a computer program product, including a computer program that, when executed, implements the method of any one of the first aspects.

[0026] The power system resonance suppression method, apparatus, device, and storage medium provided in this application include: acquiring electrical signals from multiple nodes in a power system; identifying the source node and corresponding resonant frequency of the current harmonic resonance in the power system based on the electrical signals; generating a load redistribution scheme with the goal of disrupting the resonance conditions of the source node, the load redistribution scheme being used to transfer at least one load under the source node to other nodes to change the system impedance of the source node, the system impedance being numerically equal to the parallel equivalent value of the impedances of all loads under the source node; and executing the load redistribution scheme to suppress harmonic resonance. In this process, by real-time monitoring of electrical signals at multiple nodes in the power system and by diagnosing these signals, the source node and corresponding resonant frequency causing grid resonance can be quickly located. Based on this, a load redistribution strategy aimed at disrupting the physical conditions of resonance is proposed. Specifically, by transferring some of the load under the source node to other nodes, the system impedance of the source node is directly changed, thereby disrupting the original resonance matching relationship and effectively reducing the risk of resonance. Moreover, no passive filtering or active mitigation devices are required; resonance suppression can be achieved simply by optimizing the existing network load distribution. This approach significantly reduces system transformation costs, minimizes additional operating losses and control instability risks, while also offering advantages such as rapid response, strong adaptability, and ease of engineering implementation. It provides effective technical support for building a safe and flexible new power system. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 A schematic diagram of a power system parallel resonance analysis model provided for an exemplary embodiment of this application;

[0029] Figure 2 A schematic flowchart of a power system resonance suppression method provided as an exemplary embodiment of this application;

[0030] Figure 3 A schematic diagram of a 110kV power system topology model provided for an exemplary embodiment of this application;

[0031] Figure 4 Another schematic diagram of the power system resonance suppression method provided for an exemplary embodiment of this application;

[0032] Figure 5 A schematic diagram of a power system resonance suppression device provided as an exemplary embodiment of this application;

[0033] Figure 6 A schematic diagram of the structure of an electronic device provided as an exemplary embodiment of this application.

[0034] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0036] The terms “first,” “second,” etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, products, or apparatus.

[0037] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0038] In related technologies, passive suppression schemes reshape the system impedance characteristics to disrupt resonance conditions by adding passive components such as resistors and reactors at the resonance point, but this introduces additional power frequency losses and may induce new resonance risks. Active mitigation schemes use power electronic converters to inject reverse harmonic current into the system to achieve dynamic cancellation of resonance, but this relies on high-cost, high-power power electronic equipment, and there are problems such as high control complexity and a greater risk of system instability when multiple machines are connected in parallel. System network topology reconfiguration schemes change system parameters to eliminate resonance by adjusting the grid operation mode or connection structure, but this usually relies on manual experience-based decision-making, lacks accurate modeling and optimization mechanisms, and is difficult to achieve fast adaptive resonance suppression.

[0039] During their research, the inventors discovered that capacitive and inductive components in power systems, under specific parameter combinations, can form inherent resonant frequencies. When a voltage or current disturbance occurs in the power system at this resonant frequency, it triggers a resonant amplification of the voltage or current signals, causing a sudden change in voltage or current. To elucidate this mechanism, a device was constructed as follows... Figure 1 The power system parallel resonance analysis model is shown. Figure 1 As shown, in this model, R represents the harmonic source, indicating that a certain load injects h-th harmonic current into the system; R+jhX represents the system impedance as seen from the harmonic source, where R is the equivalent resistance of the system and X is the equivalent inductive reactance of the system (unit: Ω). The capacitive reactance of a parallel capacitor bank This refers to the capacitance value of the capacitor bank (unit: F). This is the system's fundamental angular frequency; L represents the inductive reactance of the reactor connected in series with the capacitor bank, and L is the inductance of the reactor (unit: H). and These represent the h-th harmonic current phasors flowing into the impedance branch and capacitor branch of the system, respectively.

[0040] Based on circuit theory, the current flowing into the system impedance and the current flowing into the capacitor bank Satisfy the following formula:

[0041]

[0042]

[0043] in, and These are the harmonic current amplification factors (complex numbers) for the system branch and the capacitor branch, respectively, and their magnitudes are... and It characterizes the degree to which harmonic currents are amplified; when When >1, the system harmonic current is amplified; when When the harmonic frequency is greater than 1, the harmonic current of the capacitor bank is amplified. Correspondingly, when the harmonic frequency injected into the system by the harmonic source is exactly equal to the inherent resonant frequency of the system impedance and the capacitor bank impedance, harmonic parallel resonance will occur between the system impedance and the parallel capacitor bank. The necessary and sufficient condition for resonance to occur is satisfied by the following formula:

[0044]

[0045] in, The equivalent inductive reactance of the system is a key variable that determines the resonant frequency. When the condition shown in formula (3) is met, the total admittance of the circuit is at its maximum (impedance is at its minimum). and Reaching the maximum value leads to and Significant amplification, but due to the presence of system resistance, and It will not reach infinity.

[0046] Based on the above analysis of the resonance mechanism, especially the key role of the system inductive reactance X revealed by formula (3) in resonance, this application provides a power system resonance suppression scheme. By monitoring the electrical signals of multiple nodes in the power system in real time, the resonance region and frequency are dynamically identified, and the system impedance is reconstructed based on the load redistribution strategy, thereby achieving resonance suppression without additional hardware investment. The resonance suppression problem is transformed into a global optimization problem of system impedance reconstruction, which effectively improves the limitations of existing technologies that rely on hardware modification or local control. While significantly reducing system modification costs, reducing additional operating losses and control instability risks, it also has the advantages of rapid response, strong adaptability and easy engineering implementation, providing effective technical support for building a safe and flexible new power system.

[0047] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0048] Figure 2A schematic flowchart of a power system resonance suppression method provided for an exemplary embodiment of this application is shown. Figure 2 As shown, the power system resonance suppression method includes the following steps:

[0049] S201. Acquire electrical signals from multiple nodes in the power system.

[0050] Among them, electrical signals refer to instantaneous voltage and current values ​​that contain fundamental and harmonic components, measured from a specific location in the power system; a node refers to a location point in the power network that has independent voltage measurement and electrical connection status.

[0051] For example, within a target area (e.g., a power supply zone containing multiple distribution transformers), key electrical connection points are selected as monitoring nodes. These nodes are typically the low-voltage side busbars of the distribution transformers or important load connection points. Accordingly, at each monitoring node, the instantaneous three-phase AC voltage and current signals of that monitoring node are synchronously acquired using installed voltage and current transformers. The acquisition process utilizes phase-locked loop (PLL) technology to track and lock the system fundamental frequency in real time, ensuring that the sampling period is an integer multiple of the signal period to eliminate non-integer truncation errors and ensure that the sampling frequency is synchronized with the system fundamental frequency, thereby obtaining a complete periodic signal. These continuous-time analog signals are converted from analog to digital to form discrete digital signal sequences, which are then transmitted to the central processing unit of the distribution network via a communication network as a unified data source for subsequent analysis.

[0052] S202. Based on electrical signals, identify the source node and corresponding resonant frequency of the current harmonic resonance in the power system.

[0053] Among them, the resonant frequency refers to the frequency corresponding to a specific harmonic order (such as the 5th or 7th) that causes a significant amplification of voltage or current in the power system; the source node refers to the electrical node where the resonance phenomenon is first detected and the characteristics are most obvious, usually the electrical center of the resonant circuit.

[0054] Correspondingly, the central processing unit processes and analyzes the received electrical signals from each node to locate resonance events. Specifically, it performs signal transformation and decomposition on the voltage and current signals of each node, separating and obtaining the amplitude and phase information of each harmonic component. Subsequently, based on this information, it analyzes the electrical response characteristics of each node at different frequencies, identifying frequency points where the voltage response shows abnormal enhancement as suspected resonance points. For each suspected resonance point and its corresponding node, it comprehensively analyzes the impedance characteristics and voltage-current phase relationship at that frequency point to verify whether it conforms to the typical electrical characteristics of harmonic parallel resonance. When a node is verified to have undergone harmonic parallel resonance at a specific frequency, that node is determined to be the source node of the current resonance, and that specific frequency is the corresponding resonant frequency.

[0055] S203. With the goal of disrupting the resonance condition of the source node, a load redistribution scheme is generated. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of all load impedances under the source node.

[0056] The resonance condition refers to a matching relationship between the impedance parameters of inductive and capacitive elements in a power system at a specific harmonic frequency. When this relationship is met, the total impedance of the system at that frequency is purely resistive and extremely small, causing the injected harmonic current to be abnormally amplified, thus forming resonance. The system impedance specifically refers to the Thevenin equivalent impedance seen from the node of interest (such as the resonant source node S) towards the power source side of the system. Its key physical characteristic is that the value of this impedance, especially its reactance (inductive reactance) component, is numerically equal to the equivalent value obtained by parallel calculation of the impedances of all loads connected downstream of this node. Therefore, by changing the parallel combination of loads (i.e., load redistribution), the system impedance of this node can be directly changed, thereby affecting whether the resonance condition is met.

[0057] Accordingly, after accurately identifying the resonant source node (e.g., node S) and the resonant frequency (h times), the suppression decision-making process is initiated. Specifically, 1) Considering the correlation of power grid operation, other relevant electrical nodes within the power supply area of ​​node S are included in the decision-making scope, forming a collaboratively optimized network. 2) A resonant risk assessment model for the entire decision-making network is established. This model can simulate and predict: if one or more loads under node S are transferred to other nodes in the network, what impact will it have on the resonant risk of node S itself and other nodes at different harmonic frequencies? This model characterizes this impact by defining a quantitative "risk value." Its core logic is: when the simulation predicts that a node will meet the physical conditions for resonance at a certain frequency, then a higher risk value is assigned to that node at that frequency; otherwise, a lower risk value is assigned. 3) With minimizing the total risk value of all nodes in the entire decision-making network at all relevant harmonic frequencies as the optimization objective, and using the connection relationship between loads and network nodes as an adjustable decision variable, a mathematical optimization problem is constructed and solved. The optimization process aims to find an optimal load connection adjustment scheme that must first ensure the elimination of the resonance risk of node S at frequency h (even if its risk value is reduced to a low level), while minimizing the possibility of inducing new resonance risks throughout the network.

[0058] Furthermore, based on the results of the above optimization solution, one or more specific load transfer operation instructions are directly output. For example, the instruction might be explicitly stated as: "Switch the power supply of load device Lx under node S to node T within the network." This set of instructions constitutes the final load redistribution scheme.

[0059] S204. Implement a load redistribution scheme to suppress harmonic resonance.

[0060] Accordingly, after the load redistribution scheme is generated, the central processing unit of the distribution network parses the scheme into a series of specific, atomized switching operation command sequences and sends them to the corresponding field execution terminals through the distribution automation system. Correspondingly, after receiving and verifying the commands, the execution terminals remotely operate the relevant circuit breakers, load switches, or tie switches according to preset safety logic and operation sequence. Taking the typical command "switch the power supply of load device Lx under node S to node T" as an example, first, the switching device connecting load Lx and source node S is disconnected, and then the tie switch connecting load Lx and target node T is closed. This operation process accurately completes the physical switching of the load power supply path while ensuring power supply continuity (e.g., by adopting a strategy of closing before opening or rapid recovery after a brief interruption) and operational safety (e.g., performing electrical interlocking verification). Correspondingly, after the load transfer operation is completed, the parallel combination of loads downstream of source node S changes instantly. According to the definition of system impedance, its value is equal to the parallel equivalent value of all load impedances under that node, causing the system impedance of node S to be reconstructed. This reconstruction directly changes the impedance characteristics of the node at a specific harmonic frequency, thereby disrupting the original resonance matching relationship (i.e., the resonance condition is no longer satisfied). As the resonance physical condition disappears, the abnormal amplification of the original harmonic voltage and current at the source node S is effectively suppressed, the relevant electrical quantities are restored to normal levels, and the system harmonic resonance is eliminated.

[0061] The power system resonance suppression method provided in this application can quickly locate the source node and corresponding resonant frequency that causes grid resonance by real-time monitoring of electrical signals of multiple nodes in the power system and diagnosing the electrical signals. Based on this, a load redistribution strategy aimed at disrupting the physical conditions of resonance is proposed. Specifically, by transferring part of the load under the source node to other nodes, the system impedance of the source node is directly changed, thereby disrupting the original resonance matching relationship and effectively reducing the resonance risk. Moreover, no passive filtering or active control devices are required. Resonance suppression can be achieved simply by optimizing the existing network load distribution. While significantly reducing system transformation costs, reducing additional operating losses and control instability risks, it also has the advantages of rapid response, strong adaptability, and ease of engineering implementation, providing effective technical support for building a safe and flexible new power system.

[0062] In some embodiments, identifying the source node and corresponding resonant frequency of harmonic resonance in the power system based on electrical signals includes: performing spectral analysis on the electrical signals to obtain harmonic electrical characteristic information of each harmonic at each node, and generating voltage spectra corresponding to each node, wherein the harmonic electrical characteristic information includes voltage amplitude, current amplitude, and phase information; identifying and determining frequency points where the voltage amplitude exceeds a preset voltage threshold as suspected resonant frequencies based on the voltage spectra corresponding to each node; and performing impedance amplitude verification and phase analysis verification operations for each suspected resonant frequency and its corresponding node, wherein the impedance amplitude verification operation includes: determining the suspected resonant frequency. The harmonic impedance at the resonant frequency is greater than the harmonic impedance at at least one adjacent frequency of the node at the suspected resonant frequency. The phase analysis verification operation includes: determining whether the absolute value of the phase difference at the suspected resonant frequency is less than a preset phase tolerance threshold. The harmonic impedance is determined based on the voltage and current amplitudes at the suspected resonant frequency, and the phase difference is determined based on the phase information of the harmonic voltage and harmonic current at the suspected resonant frequency. If the node is at the suspected resonant frequency and the judgment results of both the impedance amplitude verification operation and the phase analysis verification operation are yes, then the node is determined to be the source node of harmonic resonance, and the suspected resonant frequency is the corresponding resonant frequency.

[0063] In some embodiments, spectral analysis of the electrical signal includes: windowing the electrical signal to obtain a windowed signal; and performing mathematical transformation on the windowed signal to obtain harmonic electrical characteristic information of each harmonic at each node.

[0064] Among them, windowing processing refers to a mathematical processing method in digital signal processing that applies a specific weighting function (window function) to both ends of the original data sequence to reduce the error caused by data truncation during spectrum analysis; harmonic electrical characteristic information is obtained through spectrum analysis and is a set of core electrical parameters used to describe each harmonic component, including at least amplitude and phase.

[0065] For example, preprocessing is required to improve accuracy before performing spectral analysis on electrical signals. Specifically, windowing is applied to the acquired discrete voltage and current sequences. For instance, a Blackman window function is used to weight and attenuate the two ends of the signal sequence to reduce spectral leakage caused by non-integer period truncation, resulting in a windowed signal sequence. Correspondingly, a mathematical transformation is performed on the windowed signal to convert the time-domain signal to the frequency domain. Through this transformation, the harmonic components contained in the signal can be accurately separated and extracted, thereby obtaining the voltage amplitude, current amplitude, and phase information corresponding to each harmonic frequency point. This information is collectively referred to as harmonic electrical characteristic information, which is the basic data for subsequent resonance identification.

[0066] Accordingly, based on the amplitude information in the harmonic electrical characteristic information, a corresponding voltage spectrum diagram is generated for each node, and the set of all detected harmonic components under each node, i.e., the set of harmonic orders, is recorded. , where i represents the i-th bus node in the power system.

[0067] Considering that during normal operation of the power system, neither voltage nor current signals undergo abrupt changes, and the voltage spectrum remains stable; however, when parallel resonance occurs, the voltage amplitude at a specific frequency will experience an abnormal surge. The system tracks the voltage spectrum of each node in real time, automatically scanning and identifying frequency points where the voltage amplitude exceeds a preset voltage threshold (which can be set, for example, based on historical normal operation data or background harmonic levels), and marking these frequency points as suspected resonance frequencies. To confirm whether resonance has occurred, a rigorous double verification is performed on each suspected resonance frequency point and its corresponding node to determine whether harmonic resonance at that frequency has occurred at that node. Specifically:

[0068] (1) Perform impedance amplitude verification operation: Based on the voltage amplitude and current amplitude at this frequency point, calculate the h-th harmonic impedance of the node according to the following formula. The calculation formula satisfies the following formula:

[0069]

[0070] in, Let h be the h-th harmonic voltage of the node. Let h be the h-th harmonic current of the node; then, this... Compare the harmonic impedance calculated at at least one adjacent frequency (e.g., h-1 and h+1 harmonics) of the node at the suspected resonant frequency; if The harmonic impedance is greater than that of its adjacent frequency points, exhibiting a "maximum" characteristic, meaning it is detected. If a maximum value is found, the impedance amplitude verification is passed.

[0071] (2) Perform phase analysis verification: Calculate the phase difference between the harmonic voltage and harmonic current at the specified frequency, and take its absolute value. If the absolute value of the phase difference is less than the preset phase tolerance threshold, it is determined that the voltage and current are close to being in phase, and the phase analysis verification operation is passed. The phase tolerance threshold, for example, is 5°, used to define the engineering range of "close to" 0 degrees. It should be noted that the phase tolerance threshold (e.g., set to 5°) is a preset engineering parameter used to physically quantify the judgment criterion that "voltage and current are close to being in phase (0°)". The setting of this threshold needs to comprehensively consider factors such as measurement accuracy, signal noise level, system imbalance, and safety margin. Its purpose is to achieve a balance between accurately identifying resonance (ideal phase difference of 0°) and tolerating normal measurement fluctuations. In practical applications, this threshold can be calibrated and optimized according to the specific system's measurement accuracy requirements and operating experience.

[0072] Correspondingly, the system ultimately determines that a node has undergone h-th harmonic resonance if and only if a node at a suspected resonant frequency simultaneously meets the conditions for impedance amplitude verification and phase analysis verification. At this point, the node is identified as the source node of the current resonance, and the suspected resonant frequency (h-th harmonic) is confirmed as the corresponding resonant frequency. The system outputs the identifier of the resonant source node, the resonant frequency h, and the set of harmonic orders for that node. This provides precise input for subsequent suppression strategies.

[0073] This application embodiment achieves accurate and reliable localization of power system resonance events by combining spectrum analysis and dual electrical feature verification. Specifically, a voltage spectrum is generated based on comprehensive harmonic electrical feature information, providing an intuitive and objective data foundation for initial resonance screening, effectively reducing the possibility of missed or false judgments that may be caused by relying on a single threshold or human experience in the traditional method. Secondly, through dual electrical feature verification of "impedance amplitude verification" and "phase analysis verification," the accuracy, robustness, and anti-interference capability of resonance identification are significantly improved. This enables the system to quickly, automatically, and accurately locate the true resonance source node and resonant frequency from a complex harmonic background, providing a prerequisite for the subsequent implementation of accurate and effective suppression strategies, thereby ensuring the final effect of the entire resonance suppression scheme.

[0074] In some embodiments, the mathematical transformation includes at least one of Fourier transform or wavelet transform.

[0075] In spectrum analysis, the mathematical transformations used can be selected and implemented based on the characteristics of the signal being analyzed and engineering requirements. For example, one implementation uses the Fourier Transform (FFT) as the mathematical transformation tool. The Fourier Transform is a core mathematical method for mapping time-domain signals to frequency-domain representations. By decomposing the signal into a sum of sine and cosine components with different frequencies, amplitudes, and phases, it can accurately and stably reveal the frequency components and energy distribution of each harmonic in the signal. It is a classic and efficient method for processing periodic or steady-state harmonic signals.

[0076] Another implementation uses wavelet transform (WT) as the mathematical transformation tool. Wavelet transform is a multi-scale analysis tool with good localization properties in both the time and frequency domains. It decomposes the signal using a set of scalable and translational basis functions (called wavelets), simultaneously capturing local details and abrupt changes in the signal's time and frequency dimensions. This approach is typically suitable for analyzing non-stationary harmonic signals whose amplitude or frequency changes dynamically over time, such as harmonics caused by fluctuations in power output from renewable energy generation.

[0077] Another implementation method combines Fourier transform and wavelet transform. For example, wavelet transform can be used to preprocess the signal to separate the frequency band of interest or transient components, and then Fourier transform can be applied to specific components for precise harmonic parameter extraction. This combination approach can achieve both the capture of non-stationary features and the accurate measurement of steady-state harmonic parameters.

[0078] In actual engineering deployment, the corresponding transformation method can be configured according to the main characteristics of the harmonic sources in the target power grid (such as steady-state harmonics of traditional industrial loads, or fluctuating and intermittent harmonics brought about by photovoltaic and wind power grid connection). Alternatively, an adaptive algorithm can be designed to dynamically select the most suitable transformation strategy based on real-time signal characteristics, so as to achieve optimal extraction and analysis of signal characteristics under complex and variable harmonic environments.

[0079] Based on the above embodiments, in some embodiments, a load redistribution scheme is generated with the goal of disrupting the resonance condition of the source node, including: identifying at least one other node on the same power supply bus as the source node as a collaborative evaluation node; constructing a system resonance risk assessment model based on the network parameters of the source node and the collaborative evaluation node; solving for the corresponding load transfer method with the goal of minimizing the output value of the system resonance risk assessment model; and generating a load redistribution scheme that indicates at least one load under the source node to at least one of the collaborative evaluation nodes based on the solution results.

[0080] For example, Figure 3A schematic diagram of a 110kV power system topology model provided for an exemplary embodiment of this application. Figure 3 As shown in the power system topology model, both transformer I and transformer II are 110kV transformers. Capacitor banks and grounding transformers are connected to the low-voltage side of both transformers. Transformer I has N loads on its low-voltage side, and the impedance of each load under its h-th harmonic is as follows: , , , and Transformer II has K loads on its low-voltage side, and the impedance of each load under the h-th harmonic is as follows: , , , .

[0081] Accordingly, once the resonant source node (e.g., the low-voltage side of transformer I, denoted as node I) and its resonant frequency h are identified, the suppression decision-making process is initiated. Specifically, 1) the collaborative evaluation nodes are determined. Based on the grid topology, other electrically related nodes located on the same 110kV power supply bus as source node I are identified, for example, in... Figure 3 In the system topology model shown, the low-voltage side of transformer II (node ​​II) is electrically tightly coupled with node I, therefore it is determined as the collaborative evaluation node. Node I and node II together constitute the domain of this optimization decision. 2) Construct a system resonance risk assessment model, for example, based on the network parameters of nodes I and II (including the harmonic impedance of each load). , , , and , , , , and 3) Establish a mathematical model that can quantitatively assess the system resonance risk under different load distributions, taking into account the parameters of their respective capacitor banks. 4) Perform optimization solutions, for example, using minimizing the output value of the above risk assessment model as the core optimization objective, perform mathematical optimization solutions on the connection relationship between loads at nodes I and II. This solution process aims to find an optimal load connection adjustment method. 5) Based on the optimization solution results, generate executable load redistribution instructions. For example, the solution result might indicate: "Transfer the Nth load under node I to node II for power supply." This instruction constitutes a specific load redistribution scheme for suppressing h resonances at node I.

[0082] In some embodiments, a system resonance risk assessment model is constructed, including: determining a set of harmonic frequencies requiring resonance risk assessment for the source node and each collaborative assessment node, wherein the set of harmonic frequencies does not include harmonic frequencies that are integer multiples of three; for each node to be assessed among the source node and all collaborative assessment nodes, and for each harmonic frequency in the set of harmonic frequencies corresponding to the node to be assessed, a penalty factor value is assigned to the node to be assessed at the harmonic frequency based on the matching state between the system impedance and the inherent impedance of the capacitor bank at the harmonic frequency after the implementation of the candidate load transfer scheme; wherein, when the system impedance and the inherent impedance of the capacitor bank reach resonance matching, a first value is assigned, otherwise a second value is assigned; the first value is greater than the second value; wherein, the inherent impedance of the capacitor bank includes the inductive reactance of the reactor and the capacitive reactance of the capacitor; and summing all the penalty factor values ​​assigned to the source node and all collaborative assessment nodes at their respective harmonic frequency sets, and using the summation result as the output value of the system resonance risk assessment model.

[0083] For example, for the source node (such as the low-voltage side of transformer I, denoted as node I) and the collaborative assessment node (such as the low-voltage side of transformer II, denoted as node II), the set of harmonic frequencies for which resonance risk assessment needs to be performed is determined respectively. and This set is typically determined based on analysis of the harmonic spectrum monitored in real time at the nodes. Furthermore, the harmonic frequency set excludes harmonic frequencies that are integer multiples of the third, i.e., h ≠ 3t (where t is a positive integer). This is because, given that a grounding transformer (such as...) is already in place on the low-voltage side of the system topology... Figure 3 As shown in the figure, the grounding transformer can provide an effective discharge path for the third, ninth and other harmonics, so that the resonance risk of these frequencies has been significantly suppressed, and therefore there is no need to include them in the optimization calculation.

[0084] For example, for node i (i can be I or II), when a load injects an h-th harmonic current into it, and the impedance relationship between the system impedance and the capacitor bank satisfies equation (5), the system will generate parallel resonance, and the voltage in the system will change, where the equivalent inductive reactance... The expression is shown in equation (6), where H equals N or K.

[0085]

[0086]

[0087] Accordingly, based on the aforementioned analysis of the resonance mechanism, when the h-th harmonic resonance is detected on the low-voltage side of transformer i, a load under its low-voltage side is transferred to the low-voltage side of another transformer (such as from node I to node II) for absorption, and the system impedance is reconstructed, so that X in equation (6) iWhen the value changes, the result of equation (5) is not 0, thus destroying the condition for resonance of the system under transformer i, and suppressing its resonance.

[0088] Correspondingly, during load redistribution, in addition to the detected h-th harmonic that causes resonance, other harmonics may also exist in the transformer. Simultaneously, non-third-order harmonics on the low-voltage side of the transformer can be transmitted between the transformer and the transmission line, resulting in a set of harmonic orders on the 10kV low-voltage side of each transformer detected on the same 110kV busbar. The harmonics should be the same. Therefore, while suppressing the h-th harmonic resonance of system nodes, it is also necessary to ensure that when load is transferred between system nodes, the harmonics of the relevant nodes are offset from the resonance point of the transformed system impedance, that is, the harmonic orders of the target node and the source node do not coincide with the new resonance point of the system impedance.

[0089] To measure whether harmonic resonance occurs at power system nodes, a penalty factor variable is established. , represents the penalty factor for the h-th harmonic at the i-th power system node, and its expression is shown in equation (7):

[0090]

[0091] in, This represents the system impedance at the i-th node after load redistribution.

[0092] Furthermore, in order to uniformly evaluate whether all harmonics at each power system node will cause resonance, variables are established. , The sum of the penalty factor evaluations for all harmonics existing under the i-th node is calculated as shown in Equation (8). This formula can traverse all harmonics under the i-th node to measure whether they will cause system resonance under the node.

[0093] (8)

[0094] in, This represents the sum of penalty factors included in the i-th node harmonic.

[0095] In optimizing load redistribution, an objective function is established that minimizes the sum of penalty factors across all nodes:

[0096] (9)

[0097] in, This represents the sum of penalty factors included in all harmonics of node I; This represents the sum of penalty factors included in all harmonics of node I; This represents the sum of penalty factors included in all harmonics at all nodes. The optimization process aims to minimize... The objective function is defined as follows: through mathematical optimization, a load redistribution scheme is sought that minimizes the overall risk of resonance between the source node and cooperating nodes at all relevant harmonic frequencies under the modified network topology, thereby systematically avoiding resonance that may be induced at any node. After the optimization solution is completed, the load redistribution operation is performed according to the optimal scheme to form a new network topology, ultimately achieving cooperative and global suppression of system resonance.

[0098] In summary, the construction and output process of the system resonance risk assessment model is as follows: For node I and node II, for each harmonic frequency in their respective harmonic frequency sets, the model is calculated based on the results obtained after the implementation of the candidate load transfer scheme. Determine whether it meets the resonance condition, and allocate the penalty factor value according to formula (7); then, sum up all the penalty factor values ​​of all nodes under their respective frequency sets to obtain the total. This serves as the final output value of the model. This output value directly and quantitatively reflects the total resonance risk faced by the entire associated system under a specific load transfer scheme, providing a precise objective function for subsequent optimization decisions.

[0099] In this embodiment, the constructed system resonance risk assessment model, by introducing a penalty factor mechanism and a global accumulation criterion, achieves scientific quantification and collaborative assessment of resonance risks in complex power grids. Specifically, by excluding third harmonics and focusing on actual high-risk frequency bands, the pertinence and efficiency of the assessment are effectively improved. Secondly, the abstract "resonance risk" is transformed into a binary penalty factor based on specific physical conditions (system impedance and capacitor bank impedance matching), achieving a precise mapping of risk from qualitative to quantitative. Furthermore, by traversing all cooperating nodes and all relevant harmonic frequencies and globally accumulating the penalty factor, the optimization decision must simultaneously consider the dual requirements of eliminating source node resonance and preventing resonance risks across the entire network. This ensures that the load redistribution scheme is not only locally effective but also globally safe, fundamentally overcoming the shortcomings of traditional local governance that may lead to secondary risks. This provides a solid mathematical and physical foundation for generating safe and reliable resonance suppression strategies.

[0100] In some embodiments, minimizing the output value of the system resonance risk assessment model is used as the optimization objective to solve for the corresponding load transfer method. This includes: establishing an optimization problem using the connection relationship of the loads in the source node and all collaborative assessment nodes as decision variables; minimizing the output value of the system resonance risk assessment model as the optimization objective of the optimization problem, and including at least one auxiliary optimization objective or constraint; the auxiliary optimization objective or constraint includes at least one of the following: load balance between nodes, limit on the number of switching operations, and power supply reliability index; solving the optimization problem to obtain a set of load connection relationships as the corresponding load transfer method.

[0101] For example, the connection status of all loads in the source node (e.g., the low-voltage side of transformer I, node I) and all collaborative evaluation nodes (e.g., the low-voltage side of transformer II, node II) are used as decision variables; the connection status of each load can be represented by a binary variable (e.g., 0 represents connection to node I, 1 represents connection to node II). Based on this, a mathematical optimization problem is constructed, the core objective function of which is to minimize the output value of the system resonance risk assessment model, that is, to minimize the sum of penalty factors defined by formula (9). This objective directly corresponds to the ultimate goal of "minimizing global resonance risk".

[0102] Meanwhile, to ensure the engineering feasibility and cost controllability of the solution, at least one auxiliary optimization objective or constraint is also included in this optimization problem, such as: 1) Load balance constraint / objective: The load rate (e.g., apparent power) of node I and node II should be as balanced as possible after optimization to reduce the probability of one node being overloaded while the other is lightly loaded due to load transfer, thereby improving the overall operating efficiency of the system; 2) Switch operation limit: Minimize or limit the number of switches that need to change state to a certain threshold to reduce operating costs, reduce operating risks, and reduce the impact on the lifespan of switching equipment; 3) Power supply reliability index: Ensure that the load transfer scheme does not cause power outages for any important users or meets specific power supply reliability requirements. Furthermore, a suitable optimization algorithm is employed to solve the aforementioned (multi-objective) optimization problem. Given that the decision variables are discrete binary variables and the solution space is enormous, intelligent optimization algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) can be used, or mathematical programming methods such as Mixed-Integer Linear Programming (MILP) can be employed for linearized models. The solution process intelligently searches through all possible load connection combinations, ultimately obtaining a set of optimal load connection relationships. This set of optimal load connection relationships clearly indicates which node each load should be connected to after optimization. For example, the solution result may be a decision vector [0, 1, 0, ..., 1], which means "Load 1, Load 3, etc. remain connected to node I, Load 2, Load N, etc. are transferred to node II." This directly defines the corresponding load transfer method, becoming the precise basis for generating specific switching operation instructions and executing network reconfiguration.

[0103] This application's embodiments elevate load redistribution decisions from empirical operations to scientific and precise intelligent decisions by establishing and solving an optimization problem centered on minimizing global resonance risk while considering multiple engineering constraints. By using load connection relationships as decision variables, optimization directly impacts the fundamental aspects of grid topology reconfiguration. The core objective function ensures the optimality of the scheme in terms of resonance suppression, while the introduction of auxiliary objectives and constraints allows the scheme to simultaneously meet multiple practical engineering requirements such as operational safety and cost control, reducing the sacrifice of other important system performance in pursuit of resonance suppression. The employed optimization algorithm can efficiently handle large-scale discrete combinatorial problems, ensuring high-quality feasible solutions even in complex scenarios, thereby outputting clear and quantifiable load transfer commands, providing crucial decision support for achieving automated, adaptive, and safe resonance suppression.

[0104] Figure 4Another schematic flowchart of a power system resonance suppression method provided for an exemplary embodiment of this application is shown. Figure 4 As shown, the power system resonance suppression method includes the following steps:

[0105] S401. Acquire electrical signals from multiple nodes in the power system.

[0106] S402. Perform spectrum analysis on the electrical signal to obtain the harmonic electrical characteristic information of each harmonic at each node, and generate the voltage spectrum corresponding to each node. The harmonic electrical characteristic information includes voltage amplitude, current amplitude and phase information.

[0107] For example, an electrical signal is windowed to obtain a windowed signal; the windowed signal is then mathematically transformed to obtain the harmonic electrical characteristic information of each harmonic at each node. The mathematical transformation includes at least one of Fourier transform or wavelet transform.

[0108] S403. Based on the voltage spectrum corresponding to each node, identify and determine the frequency points where the voltage amplitude exceeds the preset voltage threshold as suspected resonant frequency points.

[0109] S404. For each suspected resonant frequency and its corresponding node, perform impedance amplitude verification and phase analysis verification operations.

[0110] S405. Determine whether both the impedance amplitude verification operation and the phase analysis verification operation have passed.

[0111] If so, execute S406;

[0112] If not, execute S401.

[0113] S406. The node is determined to be the source node where harmonic resonance occurs, and the suspected resonant frequency is the corresponding resonant frequency.

[0114] S407. Identify at least one other node that is on the same power supply bus as the source node as a collaborative evaluation node.

[0115] S408. Based on the network parameters of the source node and the collaborative evaluation node, a system resonance risk assessment model is constructed.

[0116] For example, for the source node and each collaborative evaluation node, a set of harmonic frequencies requiring resonance risk assessment is determined. This set does not include harmonic frequencies that are integer multiples of three. For each node to be evaluated among the source node and all collaborative evaluation nodes, and for each harmonic frequency in the corresponding harmonic frequency set, a penalty factor is assigned to the node at the harmonic frequency based on the matching state between the system impedance and the inherent impedance of the capacitor bank at the harmonic frequency after the implementation of the candidate load transfer scheme. Specifically, a first value is assigned when the system impedance and the inherent impedance of the capacitor bank achieve resonance matching; otherwise, a second value is assigned. The first value is greater than the second value. The inherent impedance of the capacitor bank includes the inductive reactance of the reactor and the capacitive reactance of the capacitor. All penalty factor values ​​assigned to the source node and all collaborative evaluation nodes at their respective harmonic frequency sets are summed, and the summation result is used as the output value of the system resonance risk assessment model.

[0117] S409. With minimizing the output value of the system resonance risk assessment model as the optimization objective, solve for the corresponding load transfer mode.

[0118] For example, an optimization problem is established using the connection relationship of the load in the source node and all collaborative evaluation nodes as decision variables. The optimization problem takes minimizing the output value of the system resonance risk assessment model as the optimization objective and includes at least one auxiliary optimization objective or constraint. The auxiliary optimization objective or constraint includes at least one of the following: load balance between nodes, limit on the number of switching operations, and power supply reliability index. The optimization problem is solved to obtain a set of load connection relationships, which serve as the corresponding load transfer methods.

[0119] S410. Based on the solution results, generate a load redistribution scheme that indicates at least one load under the source node to at least one of the collaborative evaluation nodes.

[0120] S411. Implement a load redistribution scheme to suppress harmonic resonance.

[0121] In this embodiment, resonance sensing analysis based on Fourier transform or wavelet transform is used to determine the resonance region distribution and resonance frequency points according to voltage spectrum diagrams, impedance calculations, and phase analysis. When resonance is detected in the power system, based on the analysis of the resonance mechanism and the power grid network structure, the load impedance under the node is dynamically optimized and adjusted with the objective function of minimizing the sum of penalty factors under all nodes. A load under the bus node where resonance occurs is transferred, changing the system impedance and thus breaking the resonance condition at that point, thereby suppressing the target resonance. Since this process requires no additional hardware investment and can adapt to changes in system operating status, adaptive control and active suppression of system resonance can be achieved solely through real-time monitoring and dynamic adjustment.

[0122] In summary, this application has at least the following advantages:

[0123] I. By real-time monitoring of electrical signals at multiple nodes in a power system and diagnostic analysis of these signals, the source node and corresponding resonant frequency causing grid resonance can be quickly located. Based on this, a load redistribution strategy aimed at disrupting the physical conditions of resonance is proposed. Specifically, by transferring a portion of the load under the source node to other nodes, the system impedance of the source node is directly altered, thereby disrupting the original resonance matching relationship and effectively reducing resonance risk. Furthermore, no passive filtering or active mitigation devices are required; resonance suppression can be achieved simply by optimizing the existing network load distribution. This approach significantly reduces system modification costs, minimizes additional operating losses and control instability risks, while also offering advantages such as rapid response, strong adaptability, and ease of engineering implementation. It provides effective technical support for building a safe and flexible new power system.

[0124] Second, by combining spectrum analysis and dual electrical feature verification, accurate and reliable location of power system resonance events is achieved. Specifically, a voltage spectrum is generated based on comprehensive harmonic electrical feature information, providing an intuitive and objective data foundation for initial resonance screening, effectively reducing the possibility of missed or false judgments that may be caused by relying on a single threshold or human experience in the traditional method. Secondly, through dual electrical feature verification of "impedance amplitude verification" and "phase analysis verification," the accuracy, robustness, and anti-interference capability of resonance identification are significantly improved. This enables the system to quickly, automatically, and accurately locate the true resonance source node and resonant frequency from a complex harmonic background, providing a prerequisite for the subsequent implementation of accurate and effective suppression strategies, thereby ensuring the final effect of the entire resonance suppression scheme.

[0125] Third, the constructed system resonance risk assessment model, by introducing a penalty factor mechanism and a global accumulation criterion, achieves scientific quantification and collaborative assessment of resonance risks in complex power grids. Specifically, by excluding third harmonics and focusing on actual high-risk frequency bands, the model effectively improves the pertinence and efficiency of the assessment. Secondly, it transforms the abstract "resonance risk" into a binary penalty factor based on specific physical conditions (system impedance and capacitor bank impedance matching), achieving a precise mapping of risk from qualitative to quantitative. Furthermore, by traversing all cooperating nodes and all relevant harmonic frequencies and globally accumulating the penalty factor, the optimization decision must simultaneously consider the dual requirements of eliminating source node resonance and preventing network-wide resonance risks. This ensures that the load redistribution scheme is not only locally effective but also globally safe, fundamentally overcoming the shortcomings of traditional local governance that may lead to secondary risks. This provides a solid mathematical and physical foundation for generating safe and reliable resonance suppression strategies.

[0126] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0127] Figure 5 A schematic diagram of a power system resonance suppression device provided as an exemplary embodiment of this application. Figure 5 As shown, the power system resonance suppression device 50 includes an acquisition module 51, an identification module 52, a load redistribution scheme generation module 53, and an execution module 54, wherein:

[0128] Acquisition module 51 is used to acquire electrical signals from multiple nodes in the power system;

[0129] The identification module 52 is used to identify the source node and corresponding resonant frequency of the current harmonic resonance in the power system based on electrical signals.

[0130] The load redistribution scheme generation module 53 is used to generate a load redistribution scheme with the goal of disrupting the resonance condition of the source node. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of all load impedances under the source node.

[0131] Execution module 54 is used to execute a load redistribution scheme to suppress harmonic resonance.

[0132] In one possible implementation, the identification module 52 is specifically used for: performing spectral analysis on the electrical signal to obtain harmonic electrical characteristic information of each harmonic at each node, and generating voltage spectra corresponding to each node, wherein the harmonic electrical characteristic information includes voltage amplitude, current amplitude, and phase information; based on the voltage spectra corresponding to each node, identifying and determining frequency points where the voltage amplitude exceeds a preset voltage threshold as suspected resonant frequency points; for each suspected resonant frequency point and its corresponding node, performing impedance amplitude verification and phase analysis verification operations, wherein the impedance amplitude verification operation includes: determining whether the harmonic impedance at the suspected resonant frequency point is... The phase analysis verification operation includes determining whether the absolute value of the phase difference at the suspected resonant frequency point is less than a preset phase tolerance threshold. The harmonic impedance is determined based on the voltage and current amplitudes at the suspected resonant frequency point, and the phase difference is determined based on the phase information of the harmonic voltage and current at the suspected resonant frequency point. If the node is at the suspected resonant frequency point, and both the impedance amplitude verification operation and the phase analysis verification operation result are yes, then the node is determined to be the source node of harmonic resonance, and the suspected resonant frequency point is the corresponding resonant frequency.

[0133] In one possible implementation, the identification module 52 can also be used to: window the electrical signal to obtain the windowed signal; and perform mathematical transformation on the windowed signal to obtain the harmonic electrical characteristic information of each harmonic at each node.

[0134] In one possible implementation, the mathematical transformation includes at least one of Fourier transform or wavelet transform.

[0135] In one possible implementation, the load redistribution scheme generation module 53 may be specifically used to: determine at least one other node on the same power supply bus as the source node as a collaborative evaluation node; construct a system resonance risk assessment model based on the network parameters of the source node and the collaborative evaluation node; solve for the corresponding load transfer method with the goal of minimizing the output value of the system resonance risk assessment model; and generate a load redistribution scheme that indicates at least one load under the source node to at least one of the collaborative evaluation nodes based on the solution results.

[0136] In one possible implementation, the load redistribution scheme generation module 53 can also be used to: determine a set of harmonic frequencies for resonance risk assessment for the source node and each collaborative assessment node, wherein the set of harmonic frequencies does not include harmonic frequencies that are integer multiples of three; for each node to be assessed among the source node and all collaborative assessment nodes, and for each harmonic frequency in the set of harmonic frequencies corresponding to the node to be assessed, according to the matching state between the system impedance and the inherent impedance of the capacitor bank at the harmonic frequency after the implementation of the candidate load transfer scheme, assign a penalty factor value to the node to be assessed at the harmonic frequency; wherein, when the system impedance and the inherent impedance of the capacitor bank reach resonance matching, a first value is assigned, otherwise a second value is assigned; the first value is greater than the second value; wherein, the inherent impedance of the capacitor bank includes the inductive reactance of the reactor and the capacitive reactance of the capacitor; accumulate all the penalty factor values ​​assigned to the source node and all collaborative assessment nodes at their respective harmonic frequency sets, and use the accumulation result as the output value of the system resonance risk assessment model.

[0137] In one possible implementation, the load redistribution scheme generation module 53 can also be used to: establish an optimization problem using the connection relationship of the loads in the source node and all collaborative evaluation nodes as decision variables; the optimization problem takes minimizing the output value of the system resonance risk assessment model as the optimization objective, and includes at least one auxiliary optimization objective or constraint; the auxiliary optimization objective or constraint includes at least one of the load balance between nodes, the number of switching operations limit, and the power supply reliability index; and solve the optimization problem to obtain a set of load connection relationships as the corresponding load transfer method.

[0138] The power system resonance suppression device provided in this application embodiment can execute the technical solution shown in the above power system resonance suppression method embodiment. Its implementation principle and beneficial effects are similar, and will not be described again here.

[0139] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0140] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0141] It should be noted that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways; and it should be understood that the division of the various modules of the above device is only a logical functional division, and in actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can all be implemented in software through processing element calls; they can all be implemented in hardware; or some modules can be implemented by processing element calls to software, and some modules can be implemented in hardware. For example, the load redistribution scheme generation module can be a separately established processing element, or it can be integrated into a chip of the above device. Alternatively, it can be stored as program code in the memory of the above device, and its function can be called and executed by a processing element of the above device. The implementation of other modules is similar. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed by the integrated logic circuit in the hardware of the processor element or by software instructions.

[0142] For example, these modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs). As another example, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a System-On-a-Chip (SOC).

[0143] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Video Discs, DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0144] Figure 6 A schematic diagram of the structure of an electronic device provided as an exemplary embodiment of this application. For example... Figure 6 As shown, the electronic device 60 in this embodiment includes:

[0145] At least one processor 61; and a memory 62 communicatively connected to the at least one processor;

[0146] The memory 62 stores instructions that can be executed by at least one processor 61 to cause the electronic device to perform the method as described in any of the above embodiments.

[0147] Alternatively, the memory 62 can be either standalone or integrated with the processor 61.

[0148] The memory 62 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device.

[0149] The processor 61 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. Specifically, when implementing the power system resonance suppression method described in the foregoing method embodiments, the electronic device may be, for example, an electronic device with processing capabilities such as a server.

[0150] Optionally, the electronic device may also include a communication interface 63. In specific implementations, if the communication interface 63, memory 62, and processor 61 are implemented independently, they can be interconnected via a bus to complete communication. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc., but this does not imply that there is only one bus or one type of bus.

[0151] Optionally, in a specific implementation, if the communication interface 63, memory 62, and processor 61 are integrated on a single chip, then the communication interface 63, memory 62, and processor 61 can communicate through an internal interface.

[0152] The implementation principle and technical effects of the electronic device provided in this embodiment can be found in the foregoing embodiments, and will not be repeated here.

[0153] This application also provides a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are executed, they are used to implement the method steps as described in the above method embodiments. The specific implementation methods and technical effects are similar, and will not be repeated here.

[0154] The aforementioned computer-readable storage media can be implemented from 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. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0155] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in a power system resonance suppression device.

[0156] This application also provides a computer program product, including a computer program that, when executed, implements the method steps as described in the above method embodiments. The specific implementation and technical effects are similar and will not be repeated here.

[0157] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0158] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0159] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for suppressing resonance in a power system, characterized in that, include: Acquire electrical signals from multiple nodes in a power system; Based on the electrical signal, identify the source node and corresponding resonant frequency of the current harmonic resonance in the power system; With the goal of disrupting the resonance condition of the source node, a load redistribution scheme is generated. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of the impedances of all loads under the source node. The load redistribution scheme is implemented to suppress harmonic resonance.

2. The power system resonance suppression method according to claim 1, characterized in that, The step of identifying the source node and corresponding resonant frequency of harmonic resonance currently occurring in the power system based on the electrical signal includes: The electrical signal is subjected to spectrum analysis to obtain the harmonic electrical characteristic information of each harmonic under each node, and the voltage spectrum corresponding to each node is generated. The harmonic electrical characteristic information includes voltage amplitude, current amplitude and phase information. Based on the voltage spectrum corresponding to each node, frequency points where the voltage amplitude exceeds a preset voltage threshold are identified and determined as suspected resonant frequency points; For each suspected resonant frequency and its corresponding node, impedance amplitude verification and phase analysis verification operations are performed. The impedance amplitude verification operation includes: determining whether the harmonic impedance at the suspected resonant frequency is greater than the harmonic impedance of the node at at least one adjacent frequency at the suspected resonant frequency. The phase analysis verification operation includes: determining whether the absolute value of the phase difference at the suspected resonant frequency is less than a preset phase tolerance threshold. The harmonic impedance is determined based on the voltage and current amplitudes at the suspected resonant frequency, and the phase difference is determined based on the phase information of the harmonic voltage and harmonic current at the suspected resonant frequency. If the node is at the suspected resonant frequency point, and the judgment results of the impedance amplitude verification operation and the phase analysis verification operation are both yes, then the node is determined to be the source node where harmonic resonance occurs, and the suspected resonant frequency point is the corresponding resonant frequency.

3. The power system resonance suppression method according to claim 2, characterized in that, The spectral analysis of the electrical signal includes: The electrical signal is windowed to obtain a windowed signal; The windowed signal is mathematically transformed to obtain the harmonic electrical characteristic information of each harmonic at each node.

4. The power system resonance suppression method according to claim 3, characterized in that, The mathematical transformation includes at least one of Fourier transform or wavelet transform.

5. The power system resonance suppression method according to any one of claims 1 to 4, characterized in that, The method of generating a load redistribution scheme with the goal of disrupting the resonance condition of the source node includes: Identify at least one other node that is on the same power supply bus as the source node as a collaborative evaluation node; Based on the network parameters of the source node and the collaborative evaluation node, a system resonance risk assessment model is constructed; The corresponding load transfer mode is solved by minimizing the output value of the system resonance risk assessment model. Based on the solution results, a load redistribution scheme is generated that instructs at least one load under the source node to at least one of the collaborative evaluation nodes.

6. The power system resonance suppression method according to claim 5, characterized in that, The system resonance risk assessment model includes: For the source node and each of the collaborative evaluation nodes, a set of harmonic frequencies that need to be resonant risk assessed is determined. The set of harmonic frequencies does not include harmonic frequencies that are integer multiples of the third. For each node to be evaluated among the source node and all collaborative evaluation nodes, and for each harmonic frequency in the set of harmonic frequencies corresponding to the node to be evaluated, a penalty factor value is assigned to the node to be evaluated at the harmonic frequency based on the matching state between the system impedance and the inherent impedance of the capacitor bank at the harmonic frequency after the implementation of the candidate load transfer scheme. Specifically, a first value is assigned when the system impedance and the inherent impedance of the capacitor bank reach resonant matching; otherwise, a second value is assigned. The first value is greater than the second value. The system impedance is determined by the load impedance of the node to be evaluated, and the inherent impedance of the capacitor bank includes the inductive reactance of the reactor and the capacitive reactance of the capacitor bank. The values ​​of all penalty factors assigned to the source node and all collaborative evaluation nodes under their respective harmonic frequency sets are summed, and the summation result is used as the output value of the system resonance risk assessment model.

7. The power system resonance suppression method according to claim 5, characterized in that, The optimization objective of minimizing the output value of the system resonance risk assessment model to solve for the corresponding load transfer mode includes: An optimization problem is established using the connection relationships of the loads in the source node and all collaborative evaluation nodes as decision variables. The optimization problem takes minimizing the output value of the system resonance risk assessment model as the optimization objective and includes at least one auxiliary optimization objective or constraint. The auxiliary optimization objective or constraint includes at least one of the following: load balance between nodes, limit on the number of switching operations, and power supply reliability index. Solving the optimization problem yields a set of load connection relationships, which serve as the corresponding load transfer method.

8. A power system resonance suppression device, characterized in that, include: The acquisition module is used to acquire electrical signals from multiple nodes in the power system. The identification module is used to identify the source node and corresponding resonant frequency of the current harmonic resonance in the power system based on the electrical signal. A load redistribution scheme generation module is used to generate a load redistribution scheme with the goal of disrupting the resonance condition of the source node. The load redistribution scheme is used to transfer at least one load under the source node to other nodes to change the system impedance of the source node. The system impedance is numerically equal to the parallel equivalent value of the impedances of all loads under the source node. An execution module is used to execute the load redistribution scheme to suppress harmonic resonance.

9. An electronic device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory is used to store computer-executed instructions; The processor is configured to execute the computer execution instructions to implement the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed, are used to implement the method as described in any one of claims 1 to 7.

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