Novel power grid harmonic compensation method and system based on harmonic responsibility division

Abstract

The invention discloses a novel power grid harmonic compensation method and system based on harmonic responsibility division, and relates to the technical field of power grid harmonic compensation, and the method comprises the steps: collecting voltage and current signals at a common connection point of a power grid, and extracting each harmonic component from the voltage and current signals; based on each harmonic component, identifying harmonic impedance of a system side and a user side, and calculating a responsibility factor sequence corresponding to each harmonic; performing statistical analysis on the responsibility factor sequence in a preset time window to generate responsibility fluctuation entropy representing responsibility stability; dynamically correcting the compensation priority of each harmonic according to the responsibility factor and the responsibility fluctuation entropy corresponding to the responsibility factor; generating a harmonic compensation instruction of a non-user responsibility part according to the responsibility factor and the harmonic component after priority correction, and distributing available compensation capacity according to the priority when the capacity of a compensation device is limited; the method is applied to a system comprising a plurality of distributed power supplies with harmonic regulation and control capability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid harmonic compensation, in particular to a novel power grid harmonic compensation method and system based on harmonic responsibility division. BACKGROUND

[0002] The power grid harmonic compensation technology refers to a technology system for suppressing, counteracting or governing the harmonic current or voltage generated by the nonlinear load in the power system through active or passive means to improve the power quality and ensure the safe and stable operation of the power grid. Therefore, how to use advanced technical means to improve the intelligent level and security of file encryption has become one of the current problems to be solved.

[0003] In the field of power grid harmonic compensation, the traditional responsibility division method relies on offline measurement or fixed impedance assumption, but in the new type of distribution network with high proportion of distributed power access, frequent load switching and flexible topology adjustment, the harmonic impedance of the system side and the user side changes in real time, the static model causes the responsibility factor calculation to be seriously distorted, the compensation decision fails, and the existing technology only determines whether to compensate according to the instantaneous harmonic content or a single responsibility factor, without considering the time consistency of responsibility attribution. When a short-time impact, measurement noise or background harmonic mutation occurs, temporary fluctuations are easily misjudged as stable pollution sources, causing overcompensation or reverse injection, which in turn worsens the power quality. SUMMARY

[0004] In view of the above existing problems, the present application is proposed.

[0005] Therefore, the present application provides a novel power grid harmonic compensation method based on harmonic responsibility division to solve the problem that the existing technology only determines whether to compensate according to the instantaneous harmonic content or a single responsibility factor, without considering the time consistency of responsibility attribution. When a short-time impact, measurement noise or background harmonic mutation occurs, temporary fluctuations are easily misjudged as stable pollution sources, causing overcompensation or reverse injection, which in turn worsens the power quality.

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] In the first aspect, the present application provides a novel power grid harmonic compensation method based on harmonic responsibility division, which comprises:

[0008] Collecting voltage and current signals at the power grid point of common connection, and extracting harmonic components from them;

[0009] Based on the harmonic components, identifying the harmonic impedance of the system side and the user side, and calculating the responsibility factor sequence corresponding to each harmonic;

[0010] Statistically analyzing the responsibility factor sequence within a preset time window to generate a responsibility fluctuation entropy representing the responsibility stability.

[0011] According to the responsibility factor and the corresponding responsibility fluctuation entropy, the compensation priority of each harmonic is dynamically corrected;

[0012] According to the responsibility factor and the harmonic component after the priority correction, the harmonic compensation instruction of the non-user responsibility part is generated, and when the compensation device capacity is limited, the available compensation capacity is distributed according to the priority;

[0013] In a system containing multiple distributed power sources with harmonic regulation capability, the compensation instruction after capacity distribution is decomposed to the corresponding node according to the responsibility factor and the responsibility fluctuation entropy of the node, and local collaborative compensation is performed by the node.

[0014] As a preferred scheme of the new power grid harmonic compensation method based on harmonic responsibility division, wherein: the voltage and current signals are collected at the grid common connection point, and each harmonic component is extracted therefrom, and the specific steps are:

[0015] A high-precision synchronous sampling device is configured at the common connection point of the power grid, which synchronously collects three-phase voltage and three-phase current at a sampling rate not lower than 128 times of the fundamental frequency, to obtain time-domain continuous voltage signal sequence and current signal sequence;

[0016] The collected three-phase signals are converted into and components in the two-phase stationary coordinate system through a coordinate transformation module to form voltage vectors and current vectors;

[0017] The voltage vectors and current vectors are respectively subjected to sliding window discrete Fourier transform processing, wherein the window length is set to one or more complete fundamental wave periods to suppress frequency spectrum leakage;

[0018] For a preset harmonic number range, the complex voltage components and current components corresponding to each harmonic are extracted from the transformation results, wherein the voltage component of the first harmonic is denoted as , and the current component is denoted as , is an integer greater than or equal to 2 and less than or equal to a preset upper limit ;

[0019] The extracted and are reserved as basic input data for subsequent impedance identification and responsibility calculation, retaining amplitude and phase information for characterizing the electrical characteristics of the harmonics at the common connection point at this moment.

[0020] As a preferred embodiment of the novel power grid harmonic compensation method based on harmonic responsibility allocation described in this invention, the specific steps of identifying the harmonic impedances on the system side and the user side based on each harmonic component and calculating the responsibility factor sequence corresponding to each harmonic are as follows:

[0021] The data obtained at each sampling time and The input is fed into an online recursive least squares identifier, which uses... For output variables, The system-side harmonic impedance estimate and the user-side harmonic impedance estimate are dynamically updated using these as input variables.

[0022] According to the Thevenin equivalent model, the harmonic voltage at the point of common coupling is generated by the combined action of the system-side harmonic source and the user-side harmonic source, satisfying the relationship that the product of the system-side harmonic current and the system-side harmonic impedance is equal to the product of the user-side harmonic current and the user-side harmonic impedance, and the total harmonic current is the sum of the two.

[0023] Based on this physical constraint, the identifier iteratively optimizes the estimated impedance to approximate the true value, and outputs the system-side harmonic impedance. Harmonic impedance of the user side ;

[0024] Using the identified impedance values ​​on both sides, calculate the first... The responsible factor for subharmonics It is defined as the ratio of the magnitude of the system-side impedance to the sum of the magnitudes of the impedances on both sides, and its expression is:

[0025] ;

[0026] Among them, responsibility factors Characterizing the user side's connection to the common connection point The contribution ratio of subharmonic current;

[0027] Record continuously at fixed time intervals Forming a length of The responsibility factor sequence serves as the data basis for subsequent stability analysis.

[0028] As a preferred embodiment of the novel power grid harmonic compensation method based on harmonic responsibility allocation described in this invention, the specific steps for performing statistical analysis on the responsibility factor sequence within a preset time window to generate a responsibility fluctuation entropy characterizing responsibility stability are as follows:

[0029] Select containing A time window of consecutive sampling points is used to normalize the sequence of responsibility factors within the window so that their values ​​are distributed within a closed interval.

[0030] Divide the closed interval into Divide the data into equal-width sub-intervals and count the number of times the responsibility factor value appears in each sub-interval.

[0031] The probability of occurrence of each sub-interval is calculated based on the statistical results. After removing the intervals with a probability of zero, a set of non-zero probabilities is constructed.

[0032] Shannon's information entropy is calculated using probability sets and used as the responsibility fluctuation entropy. Its expression is:

[0033] ;

[0034] in, For the first The probability of the occurrence of the responsibility factor in each sub-interval is summed to cover all non-zero probability terms.

[0035] The responsibility fluctuation entropy The time-varying uncertainty used to quantify the user's responsibility for the h-th harmonic includes:

[0036] when When the value approaches 0, it indicates that the attribution of responsibility is highly stable;

[0037] when A larger value indicates frequent fluctuations in responsibility, suggesting the presence of measurement interference or external disturbances.

[0038] The generated With the corresponding Together they constitute a two-dimensional assessment index for harmonic liability.

[0039] As a preferred embodiment of the novel power grid harmonic compensation method based on harmonic responsibility allocation described in this invention, the specific steps of dynamically correcting the compensation priority of each harmonic according to the responsibility factor and its corresponding responsibility fluctuation entropy are as follows:

[0040] Pre-set the threshold for responsibility fluctuation entropy This is used to distinguish between stable and unstable states of responsibility.

[0041] For each harmonic number If the responsibility fluctuation entropy Not greater than If the attribution of responsibility for the harmonics is deemed reliable, a basic priority weight is assigned, which is equal to the proportion of non-user responsibility (1 − 1). ;

[0042] like Greater than Therefore, an exponential decay factor is introduced to reduce its priority. The expression for the decay factor is:

[0043] ;

[0044] wherein, is a preset sensitivity coefficient, used to adjust the influence strength of the entropy value on the priority;

[0045] The modified priority weight is:

[0046] ;

[0047] The modified priority weight reflects the responsibility degree and responsibility stability of the non-user;

[0048] According to the size of all , the harmonic orders are arranged in descending order to form a dynamic compensation priority list.

[0049] As a preferred scheme of the new power grid harmonic compensation method based on harmonic responsibility division, wherein: the harmonic compensation instructions of the non-user responsibility part are generated according to the responsibility factor and the harmonic component after priority modification, and when the compensation device capacity is limited, the available compensation capacity is distributed according to the priority, and the specific steps are:

[0050] According to the dynamic compensation priority list, each harmonic is processed in turn;

[0051] For the current processed harmonic, , the theoretical required compensation current amplitude is calculated, which is equal to the product of the non-user responsibility proportion and the measured harmonic current amplitude of the point of common coupling;

[0052] The allocated compensation capacity is initialized to zero, and the maximum allowed output current amplitude of the compensation device is set as ;

[0053] It is judged whether the sum of the current allocated capacity and the theoretical compensation current of this time exceeds ;

[0054] If not, the compensation instruction of this harmonic is allocated in full, and is added to the allocated capacity;

[0055] If it exceeds, only the remaining available capacity is allocated as the compensation instruction of this harmonic, and the compensation allocation of all subsequent low-priority harmonics is terminated;

[0056] The formed harmonic compensation instruction set constitutes the control target of the compensation device.

[0057] As a preferred scheme of the new power grid harmonic compensation method based on harmonic responsibility division, wherein: in the system containing a plurality of distributed power sources with harmonic regulation capacity, the compensation instruction after capacity allocation is decomposed to the corresponding node according to the responsibility factor and responsibility fluctuation entropy of the node, and the local collaborative compensation is executed by the node, and the specific steps are as follows:

[0058] All distributed nodes with harmonic current injection capacity in the system are identified, including photovoltaic inverters, energy storage converters and local active filters.

[0059] For each distributed node , the responsibility factor and the responsibility fluctuation entropy of the first harmonic in the historical operation are obtained. ;

[0060] Based on the responsibility information of the node, the allocation weight of the node to the global compensation task is calculated, and the weight calculation formula is as follows:

[0061] ;

[0062] Wherein, the summation range covers all the distributed nodes participating in the collaboration ;

[0063] The weight reflects the comprehensive contribution of the node to the non-responsibility degree and responsibility stability of the first harmonic ;

[0064] The global compensation instruction is decomposed into the local compensation instruction of each node according to the weight ;

[0065] After receiving the local instruction, each node combines the real-time available capacity of the inverter or converter to perform amplitude limiting processing, and generates the corresponding PWM driving signal to realize the local harmonic current injection.

[0066] In the second aspect, the application provides a new power grid harmonic compensation system based on harmonic responsibility division, comprising:

[0067] A harmonic signal acquisition module, a harmonic impedance identification module, a responsibility stability analysis module, a compensation priority correction module, a capacity limited instruction generation module and a distributed collaborative execution module.

[0068] The harmonic signal acquisition module is used for synchronously acquiring voltage and current signals at the power grid point of common connection, and extracting harmonic components.

[0069] The harmonic impedance identification module is configured to identify harmonic impedances of the system side and the user side in real time based on the harmonic components, and calculate a responsibility factor sequence corresponding to each harmonic;

[0070] The responsibility stability analysis module is configured to statistically analyze the responsibility factor sequence within a preset time window, and generate a responsibility fluctuation entropy representing responsibility stability;

[0071] The compensation priority correction module is configured to dynamically correct a compensation priority of each harmonic according to the responsibility factor and the corresponding responsibility fluctuation entropy;

[0072] The capacity-limited instruction generation module is configured to generate a harmonic compensation instruction of a non-user responsibility part according to the responsibility factor and the harmonic component after priority correction, and allocate available compensation capacity according to the priority when the compensation device capacity is limited.

[0073] The distributed collaborative execution module is configured to decompose the compensation instruction after capacity allocation to corresponding nodes according to the responsibility factor and the responsibility fluctuation entropy of the nodes, and execute local collaborative compensation by the nodes in a system comprising a plurality of distributed power sources with harmonic control capability.

[0074] In a third aspect, the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, any step of the novel power grid harmonic compensation method based on harmonic responsibility division according to the first aspect of the present application is implemented.

[0075] In a fourth aspect, the present application provides a computer readable storage medium storing a computer program, wherein when the computer program is executed by a processor, any step of the novel power grid harmonic compensation method based on harmonic responsibility division according to the first aspect of the present application is implemented.

[0076] The present application has the following advantages: harmonic signals are collected in real time at a point of common coupling, harmonic impedances of the system side and the user side are dynamically identified, responsibility factors of each harmonic are accurately calculated, responsibility fluctuation entropy generated by statistical analysis on the time sequence of the responsibility factors is introduced, the stability of responsibility attribution is effectively identified, the compensation priority is corrected based on the responsibility factor and the responsibility fluctuation entropy, on-demand and orderly allocation of a non-user responsibility part is realized when the compensation device capacity is limited, the compensation instruction is decomposed to distributed power sources with harmonic control capability according to node responsibility characteristics, and local collaborative governance is completed. BRIEF DESCRIPTION OF DRAWINGS

[0077] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0078] Figure 1 Flow chart of the new power grid harmonic compensation method based on harmonic responsibility division in embodiment 1.

[0079] Figure 2 Schematic diagram of the new power grid harmonic compensation system based on harmonic responsibility division in embodiment 1. DETAILED DESCRIPTION

[0080] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification.

[0081] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0082] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0083] Embodiment, refer to Figure 1 and Figure 2 , the embodiment of the present application provides a new power grid harmonic compensation method based on harmonic responsibility division, comprising the following steps:

[0084] S1, collecting voltage and current signals at the power grid point of common connection, and extracting each harmonic component therefrom;

[0085] Further, a high-precision synchronous sampling device is configured at the point of common connection of the power grid, and the high-precision synchronous sampling device synchronously collects three-phase voltage and three-phase current at a sampling rate not lower than 128 times of the fundamental frequency, to obtain time-domain continuous voltage signal sequence and current signal sequence;

[0086] The collected three-phase signals are converted into two-phase static coordinate system and components through a coordinate transformation module, to form voltage vector and current vector;

[0087] Sliding window discrete Fourier transform processing is applied to the voltage vector and the current vector respectively, wherein the window length is set to one or more complete fundamental cycles to suppress spectral leakage;

[0088] For a preset harmonic order range, the complex form voltage and current components corresponding to each harmonic are extracted from the transformation results, where the first harmonic is... The voltage component of the subharmonic is denoted as The current component is denoted as , It is greater than or equal to 2 and less than or equal to the preset upper limit. Integers;

[0089] Extracted and As the basic input data for subsequent impedance identification and liability calculation, the amplitude and phase information are retained to characterize the electrical characteristics of harmonics at the point of common coupling at that moment.

[0090] It should be noted that by combining high-precision synchronous sampling with sliding window discrete Fourier transform, not only is the time-domain continuity and frequency-domain accuracy of harmonic component extraction ensured, but the spectral leakage problem caused by non-integer period sampling is also effectively suppressed. This provides a high-fidelity, low-noise raw data foundation for subsequent impedance identification and responsibility allocation, and improves the reliability and real-time performance of the entire harmonic responsibility assessment system.

[0091] S2. Based on each harmonic component, identify the harmonic impedance on the system side and the user side, and calculate the responsibility factor sequence corresponding to each harmonic.

[0092] Furthermore, the data obtained at each sampling time... and The input is fed into the online recursive least squares identifier, which then uses... For output variables, The system-side harmonic impedance estimate and the user-side harmonic impedance estimate are dynamically updated using these as input variables.

[0093] According to the Thevenin equivalent model, the harmonic voltage at the point of common coupling is generated by the combined action of the system-side harmonic source and the user-side harmonic source, satisfying the relationship that the product of the system-side harmonic current and the system-side harmonic impedance is equal to the product of the user-side harmonic current and the user-side harmonic impedance, and the total harmonic current is the sum of the two.

[0094] Based on this physical constraint, the identifier iteratively optimizes the estimated impedance to approximate the true value, and outputs the system-side harmonic impedance. Harmonic impedance of the user side ;

[0095] With the identified two-side impedance amplitudes, the responsibility factor of the 3rd harmonic is calculated which is defined as the ratio of the system-side impedance amplitude to the sum of the two-side impedance amplitudes, expressed as:

[0096]

[0097] wherein the responsibility factor characterizes the contribution proportion of the user-side to the 3rd harmonic current at the point of common coupling (PCC) ;

[0098] is recorded continuously at fixed time intervals, forming a responsibility factor sequence with length , which serves as the data basis for subsequent stability analysis;

[0099] It should be noted that the online recursive least squares impedance identification mechanism based on the Thevenin equivalent model can dynamically track the impedance fluctuations caused by changes in power grid topology and distributed power switching, avoiding the responsibility misjudgment caused by the traditional fixed impedance assumption. The generated responsibility factor sequence truly reflects the actual contribution of the user-side to the harmonic current under different operating conditions, providing a physically interpretable and engineering implementable quantitative basis for realizing compensation according to responsibility.

[0100] S3, statistically analyzing the responsibility factor sequence within a preset time window to generate a responsibility fluctuation entropy that characterizes the responsibility stability;

[0101] Further, a time window containing consecutive sampling points is selected, and the responsibility factor sequence within the window is normalized so that its numerical value is distributed in a closed interval;

[0102] The closed interval is divided into equal-width subintervals, and the number of times the responsibility factor value appears in each subinterval is counted;

[0103] Based on the statistical results, the appearance probability of each subinterval is calculated, and after eliminating the intervals with zero probability, a non-zero probability set is constructed;

[0104] The Shannon information entropy is calculated using the probability set as the responsibility fluctuation entropy , whose expression is:

[0105]

[0106] wherein is the responsibility factor appearance probability of the th subinterval, and the summation range covers all non-zero probability terms;

[0107] The responsibility fluctuation entropy​​​​​ For quantifying the time-varying uncertainty of user responsibility for the hth harmonic, including:

[0108] When approaches 0, it indicates that the responsibility attribution is highly stable;

[0109] When is larger, it indicates that the responsibility fluctuates frequently, and there is a measurement disturbance or external disturbance effect;

[0110] The generated and the corresponding together constitute a two-dimensional evaluation index of harmonic responsibility;

[0111] It should be noted that the introduction of the responsibility fluctuation entropy index based on Shannon information entropy breaks through the limitation of relying only on instantaneous responsibility factors for judgment, and for the first time, the stability of harmonic responsibility is quantitatively evaluated from the time evolution dimension. The two-dimensional evaluation mechanism can effectively identify the abnormal fluctuations of responsibility caused by measurement disturbance, load mutation or background harmonic disturbance, thereby avoiding excessive or incorrect compensation for unstable responsibility sources, and enhancing the robustness and decision-making credibility of the method under complex disturbance conditions.

[0112] S4, according to the responsibility factor and its corresponding responsibility fluctuation entropy, dynamically corrects the compensation priority of each harmonic;

[0113] Furthermore, a threshold value of responsibility fluctuation entropy is preset for distinguishing between stable and unstable states of responsibility;

[0114] For each harmonic order , if the responsibility fluctuation entropy is not greater than , it is determined that the responsibility attribution of the harmonic is reliable, and a basic priority weight is given, which is equal to the non-user responsibility proportion 1− ;

[0115] If is greater than , an exponential decay factor is introduced to reduce its priority, and the expression of the decay factor is:

[0116] ;

[0117] wherein, is a preset sensitivity coefficient for adjusting the influence strength of the entropy value on the priority;

[0118] The corrected priority weight is:

[0119] ;

[0120] The corrected priority weight reflecting the degree of non-user responsibility and responsibility stability;

[0121] according to all the harmonic order is arranged in descending order according to the size, forming a dynamic compensation priority list;

[0122] It should be noted that by fusing the responsibility fluctuation entropy and the responsibility factor to generate a dynamic priority weight, the compensation strategy is realized from a static responsibility response to a stable responsibility priority. The mechanism not only guarantees the fairness of governance, but also automatically suppresses the compensation investment for harmonics with ambiguous responsibility attribution, optimizes the allocation efficiency of limited governance resources, and is especially suitable for practical engineering scenarios where power quality standards are increasingly stringent and compensation capacity is limited.

[0123] S5, generating harmonic compensation instructions for the non-user responsibility part according to the priority corrected responsibility factor and harmonic component, and distributing the available compensation capacity according to the priority when the compensation device capacity is limited;

[0124] Further, each harmonic is processed in turn according to the dynamic compensation priority list;

[0125] for the current processing of the first harmonic, the theoretical required compensation current amplitude is calculated, which is equal to the product of the non-user responsibility proportion and the measured harmonic current amplitude at the point of common coupling;

[0126] Initialize the allocated compensation capacity to zero, and set the maximum allowed output current amplitude of the compensation device as ;

[0127] determine whether the sum of the current allocated capacity and the theoretical compensation current exceeds ;

[0128] If not, the compensation instruction for this harmonic is allocated in full, and the allocated capacity is accumulated;

[0129] If it exceeds, only the remaining available capacity is allocated as the compensation instruction for this harmonic, and the compensation allocation for all subsequent low-priority harmonics is terminated;

[0130] The formed harmonic compensation instruction set constitutes the control target of the compensation device;

[0131] It should be noted that under the capacity constraint condition, the dynamic priority is used for ordered allocation, which ensures that the compensation device always preferentially offsets the external harmonic components with clear and stable responsibility, not only meets the key harmonic governance needs, but also avoids device overload or invalid action caused by blind full compensation. The amplitude limiting allocation logic enables the system to achieve optimal governance efficiency within the hardware capability boundary, improving the practicality and economy of the compensation strategy.

[0132] S6. In a system containing multiple distributed power sources with harmonic regulation capabilities, the compensation command after capacity allocation is decomposed to the corresponding nodes according to the node's responsibility factor and responsibility fluctuation entropy, and the nodes perform local collaborative compensation.

[0133] Furthermore, identify all distributed nodes in the system that have harmonic current injection capability, including photovoltaic inverters, energy storage converters, and local active filters.

[0134] For each distributed node To obtain its historical operation data for the first The responsible factor for subharmonics and responsibility fluctuation entropy ;

[0135] Based on the node's responsibility information, its weight in the global compensation task is calculated. The weight calculation formula is as follows:

[0136] ;

[0137] The summation covers all distributed nodes participating in the collaboration. ;

[0138] Weight Reflecting the nodes For the The combined contribution of the non-liability degree of subharmonics and the liability stability;

[0139] Global compensation commands are weighted. It is decomposed into local compensation instructions for each node;

[0140] After receiving local instructions, each node performs amplitude limiting processing based on the real-time available capacity of its own inverter or converter, and generates corresponding PWM drive signals to achieve local harmonic current injection.

[0141] It should be noted that by intelligently decomposing the global compensation task to distributed power sources according to the node responsibility characteristics, and making full use of the harmonic control potential of existing power electronic equipment such as photovoltaic inverters and energy storage converters, a collaborative governance model of on-site generation and on-site governance is realized. The architecture not only reduces the dependence on centralized high-capacity active filters, but also avoids the erroneous participation of unstable nodes through the responsibility fluctuation entropy weighting mechanism, thus promoting the evolution of harmonic governance towards a new paradigm of distributed, intelligent, and resource reuse.

[0142] This embodiment also provides a novel power grid harmonic compensation system based on harmonic responsibility allocation, including:

[0143] Harmonic signal acquisition module, harmonic impedance identification module, responsibility stability analysis module, compensation priority correction module, capacity-limited instruction generation module, and distributed collaborative execution module;

[0144] a harmonic signal acquisition module, configured to synchronously acquire voltage and current signals at a point of common coupling and extract harmonic components;

[0145] a harmonic impedance identification module, configured to identify harmonic impedances of a system side and a user side in real time based on the harmonic components and calculate a responsibility factor sequence corresponding to each harmonic;

[0146] a responsibility stability analysis module, configured to statistically analyze the responsibility factor sequence in a preset time window and generate a responsibility fluctuation entropy representing responsibility stability;

[0147] a compensation priority correction module, configured to dynamically correct compensation priorities of the harmonics according to the responsibility factors and the corresponding responsibility fluctuation entropies;

[0148] a capacity limitation instruction generation module, configured to generate harmonic compensation instructions for a non-user responsibility part according to the responsibility factors and the harmonic components after the priority correction, and allocate available compensation capacity according to the priorities when the compensation device capacity is limited;

[0149] a distributed collaborative execution module, configured to decompose the compensation instructions after the capacity allocation to corresponding nodes according to the responsibility factors and the responsibility fluctuation entropies of the nodes in a system including multiple distributed power sources with harmonic regulation capabilities, and execute local collaborative compensation by the nodes.

[0150] The embodiment also provides a computer device suitable for the new power grid harmonic compensation method based on harmonic responsibility division, including a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to realize the new power grid harmonic compensation method based on harmonic responsibility division proposed in the above embodiment.

[0151] The computer device can be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to perform wired or wireless communication with external terminals. The wireless communication can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device. In addition, the input device can be an external keyboard, touchpad or mouse, etc.

[0152] The embodiment also provides a storage medium on which a computer program is stored, the program being executed by a processor to implement the new power grid harmonic compensation method based on harmonic responsibility division proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk, or an optical disk.

[0153] To sum up, the application accurately calculates the responsibility factor of each harmonic by collecting harmonic signals in real time at the common connection point and dynamically identifying the harmonic impedance of the system side and the user side, effectively identifies the stability of the responsibility attribution by introducing the responsibility fluctuation entropy generated by statistical analysis on the time sequence of the responsibility factor, corrects the compensation priority based on the responsibility factor and the responsibility fluctuation entropy, realizes the on-demand and orderly distribution of the non-user responsibility part when the capacity of the compensation device is limited, decomposes the compensation instruction to the distributed power supply with harmonic control capability according to the node responsibility characteristics, and completes the local collaborative governance.

[0154] It should be noted that the above embodiments are only used to illustrate the technical solutions of the application rather than limit the application. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the application, and all of them should be covered in the scope of the claims of the application.

Claims

1. A novel power grid harmonic compensation method based on harmonic responsibility allocation, characterized in that, include: Voltage and current signals are collected at the point of common coupling of the power grid, and harmonic components are extracted from them. Based on each harmonic component, the harmonic impedance on the system side and the user side is identified, and the responsibility factor sequence corresponding to each harmonic is calculated. Statistical analysis is performed on the responsibility factor sequence within a preset time window to generate responsibility fluctuation entropy, which characterizes the stability of responsibility. The compensation priority of each harmonic is dynamically adjusted based on the responsibility factor and its corresponding responsibility fluctuation entropy. Based on the priority-corrected responsibility factor and harmonic components, a harmonic compensation instruction for the non-user responsibility portion is generated, and the available compensation capacity is allocated according to the priority when the compensation device capacity is limited. In a system containing multiple distributed power sources with harmonic regulation capabilities, the compensation command after capacity allocation is decomposed to the corresponding nodes according to the node's responsibility factor and responsibility fluctuation entropy, and the nodes perform local collaborative compensation.

2. The novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 1, characterized in that: The specific steps for acquiring voltage and current signals at the power grid's point of common coupling and extracting harmonic components are as follows: A high-precision synchronous sampling device is configured at the common connection point of the power grid. The high-precision synchronous sampling device synchronously collects the three-phase voltage and three-phase current at a sampling rate of not less than 128 times the fundamental frequency to obtain a time-domain continuous voltage signal sequence and current signal sequence. The acquired three-phase signals are converted into two-phase stationary coordinates using a coordinate transformation module. and The components form voltage and current vectors; Sliding window discrete Fourier transform processing is applied to the voltage vector and the current vector respectively, wherein the window length is set to one or more complete fundamental cycles to suppress spectral leakage; For a preset harmonic order range, the complex form voltage and current components corresponding to each harmonic are extracted from the transformation results, where the first harmonic is... The voltage component of the subharmonic is denoted as The current component is denoted as , It is greater than or equal to 2 and less than or equal to the preset upper limit. Integers; Extracted and As the basic input data for subsequent impedance identification and liability calculation, the amplitude and phase information are retained to characterize the electrical characteristics of harmonics at the point of common coupling at that moment.

3. A novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 2, characterized in that: The specific steps for identifying the harmonic impedance on the system side and the user side based on each harmonic component, and calculating the responsibility factor sequence corresponding to each harmonic, are as follows: The data obtained at each sampling time and The input is fed into an online recursive least squares identifier, which uses... For output variables, The system-side harmonic impedance estimate and the user-side harmonic impedance estimate are dynamically updated using these as input variables. According to the Thevenin equivalent model, the harmonic voltage at the point of common coupling is generated by the combined action of the system-side harmonic source and the user-side harmonic source, satisfying the relationship that the product of the system-side harmonic current and the system-side harmonic impedance is equal to the product of the user-side harmonic current and the user-side harmonic impedance, and the total harmonic current is the sum of the two. Based on this physical constraint, the identifier iteratively optimizes the estimated impedance to approximate the true value, and outputs the system-side harmonic impedance. Harmonic impedance of the user side ; Using the identified impedance values ​​on both sides, calculate the first... The responsible factor for subharmonics It is defined as the ratio of the magnitude of the system-side impedance to the sum of the magnitudes of the impedances on both sides, and its expression is: ； Among them, responsibility factors Characterizing the user side's connection to the common connection point The contribution ratio of subharmonic current; Record continuously at fixed time intervals Forming a length of The responsibility factor sequence serves as the data basis for subsequent stability analysis.

4. A novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 3, characterized in that: The specific steps for performing statistical analysis on the responsibility factor sequence within a preset time window to generate a responsibility fluctuation entropy characterizing responsibility stability are as follows: Select containing A time window of consecutive sampling points is used to normalize the sequence of responsibility factors within the window so that their values ​​are distributed within a closed interval. Divide the closed interval into Divide the data into equal-width sub-intervals and count the number of times the responsibility factor value appears in each sub-interval. The probability of occurrence of each sub-interval is calculated based on the statistical results. After removing the intervals with a probability of zero, a set of non-zero probabilities is constructed. Shannon's information entropy is calculated using probability sets and used as the responsibility fluctuation entropy. Its expression is: ； in, For the first The probability of the occurrence of the responsibility factor in each sub-interval is summed to cover all non-zero probability terms. The responsibility fluctuation entropy The time-varying uncertainty used to quantify the user's responsibility for the h-th harmonic includes: when When the value approaches 0, it indicates that the attribution of responsibility is highly stable; when A larger value indicates frequent fluctuations in responsibility, suggesting the presence of measurement interference or external disturbances. The generated With the corresponding Together they constitute a two-dimensional assessment index for harmonic liability.

5. A novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 4, characterized in that: The specific steps for dynamically adjusting the compensation priority of each harmonic based on the responsibility factor and its corresponding responsibility fluctuation entropy are as follows: Pre-set the threshold for responsibility fluctuation entropy This is used to distinguish between stable and unstable states of responsibility. For each harmonic number If the responsibility fluctuation entropy Not greater than If the attribution of responsibility for the harmonics is deemed reliable, a basic priority weight is assigned, which is equal to the proportion of non-user responsibility (1 − 1). ; like Greater than Therefore, an exponential decay factor is introduced to reduce its priority. The expression for the decay factor is: ; in, This is a preset sensitivity coefficient used to adjust the intensity of the entropy value's influence on priority. The revised priority weights are: ; The corrected priority weight This reflects the degree of responsibility and stability of responsibility not borne by the user. According to all The values ​​of the harmonics are sorted in descending order to form a dynamic compensation priority list.

6. A novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 5, characterized in that: The process involves generating harmonic compensation instructions for the non-user-responsible portion based on the priority-corrected responsibility factor and harmonic components, and allocating available compensation capacity according to the priority when the compensation device capacity is limited. The specific steps are as follows: Each harmonic is processed sequentially according to the dynamic compensation priority list; For the currently processed number The theoretically required compensation current amplitude for subharmonics is calculated. The theoretically required compensation current amplitude is equal to the product of the non-user liability ratio and the measured harmonic current amplitude at the point of common coupling. Initialize the allocated compensation capacity to zero, and set the maximum allowable output current amplitude of the compensation device to be zero. ; Determine whether the sum of the currently allocated capacity and the theoretical compensation current exceeds [the limit]. ; If the limit is not exceeded, the compensation command for that harmonic will be fully allocated and added to the allocated capacity. If the limit is exceeded, only the remaining available capacity will be allocated as the compensation instruction for that harmonic, and the compensation allocation for all subsequent low-priority harmonics will be terminated. The set of harmonic compensation commands formed constitutes the control target of the compensation device.

7. A novel power grid harmonic compensation method based on harmonic responsibility allocation as described in claim 6, characterized in that: In a system containing multiple distributed power sources with harmonic regulation capabilities, the compensation command after capacity allocation is decomposed to the corresponding nodes according to the node's responsibility factor and responsibility fluctuation entropy, and the nodes perform local collaborative compensation. The specific steps are as follows: Identify all distributed nodes in the system that have harmonic current injection capability, including photovoltaic inverters, energy storage converters, and local active filters; For each distributed node To obtain its historical operation data for the first The responsible factor for subharmonics and responsibility fluctuation entropy ; Based on the node's responsibility information, its weight in the global compensation task is calculated. The weight calculation formula is as follows: ; The summation covers all distributed nodes participating in the collaboration. ; Weight Reflecting the nodes For the The combined contribution of the non-liability degree of subharmonics and the liability stability; Global compensation commands are weighted. It is decomposed into local compensation instructions for each node; After receiving local instructions, each node performs amplitude limiting processing based on the real-time available capacity of its own inverter or converter, and generates corresponding PWM drive signals to achieve local harmonic current injection.

8. A novel power grid harmonic compensation system based on harmonic responsibility allocation, comprising the novel power grid harmonic compensation method based on harmonic responsibility allocation as described in any one of claims 1 to 7, characterized in that, include: Harmonic signal acquisition module, harmonic impedance identification module, responsibility stability analysis module, compensation priority correction module, capacity-limited instruction generation module, and distributed collaborative execution module; The harmonic signal acquisition module is used to synchronously acquire voltage and current signals at the power grid common connection point and extract each harmonic component. The harmonic impedance identification module is used to identify the harmonic impedance of the system side and the user side in real time based on the harmonic components, and to calculate the responsibility factor sequence corresponding to each harmonic. The responsibility stability analysis module is used to perform statistical analysis on the responsibility factor sequence within a preset time window to generate responsibility fluctuation entropy, which characterizes responsibility stability. The compensation priority correction module is used to dynamically correct the compensation priority of each harmonic based on the responsibility factor and its corresponding responsibility fluctuation entropy. The capacity-limited instruction generation module is used to generate harmonic compensation instructions for the non-user-responsible part based on the responsibility factor and harmonic components after priority correction, and to allocate available compensation capacity according to the priority when the compensation device capacity is limited. The distributed collaborative execution module is used in a system containing multiple distributed power sources with harmonic regulation capabilities to decompose the compensation instructions after capacity allocation to the corresponding nodes according to the responsibility factor and responsibility fluctuation entropy of the nodes, and the nodes perform local collaborative compensation.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the novel power grid harmonic compensation method based on harmonic responsibility allocation as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the novel power grid harmonic compensation method based on harmonic responsibility allocation as described in any one of claims 1 to 7.

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