Harmonic influence degree determination method and device, computer device, readable storage medium and program product

Abstract

The application relates to a harmonic influence degree determination method and device, computer equipment, a readable storage medium and a program product. The method comprises the following steps: when it is detected that a harmonic source of a power system emits harmonics, a collection time window to which a current moment belongs is defined as a current time window, and the current emission times of the harmonic source are obtained; the same times of historical harmonics in a previous time window and corresponding historical moments are matched, current and historical monitoring voltage values of a harmonic monitoring node are collected respectively, and current and historical injection current values of the harmonic source are collected; voltage value differences and current value differences are calculated, and the influence degree of the harmonics on the monitoring node is solved based on the two types of differences; according to the difference analysis of the electrical quantities of the same source and the same times of the harmonics in the previous and subsequent time windows, the steady-state background harmonic interference is avoided, the harmonic disturbance contribution of each harmonic source is accurately quantified, the harmonic responsibility of different harmonic sources can be reliably distinguished, and accurate basis is provided for power grid harmonic tracing, responsibility judgment and targeted harmonic treatment.

Description

Technical Field

[0001] This application relates to the field of power grid detection technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for determining the degree of harmonic influence. Background Technology

[0002] With the continued advancement of the "dual-carbon" strategic goals, the penetration rate of new energy power generation and power electronic devices in the power system is constantly increasing, and the power grid operation mode is gradually evolving from being dominated by traditional synchronous power sources to a highly power-electronic direction. The large-scale integration of distributed power sources, flexible DC transmission devices, and various nonlinear loads has led to the characteristics of multi-source, strong coupling, and expanded impact range of harmonic problems within the system. At the point of common coupling (PCC), multiple harmonic sources may act simultaneously and superimpose on each other, resulting in significant fluctuations in harmonic levels and increasing the difficulty of harmonic mitigation and liability determination. Summary of the Invention

[0003] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for determining the degree of harmonic influence, which can accurately determine the degree of harmonic influence on harmonic monitoring nodes, in response to the above-mentioned technical problems.

[0004] In a first aspect, this application provides a method for determining the degree of harmonic influence, the method comprising:

[0005] If a harmonic source in the power system is detected emitting a current harmonic at the current moment, the data acquisition time window in which the current moment is located is determined as the current time window, and for any current harmonic source emitting a current harmonic, the current number of times the current harmonic source emits the harmonic within the current time window is obtained;

[0006] For the previous time window before the current time window, determine the historical harmonics corresponding to the current emission number among the harmonics emitted by the current harmonic source in the previous time window, and obtain the historical moment when the current harmonic source emitted the historical harmonics;

[0007] Obtain the current monitoring voltage value of any harmonic monitoring node at the current time and the historical monitoring voltage value at the historical time; and obtain the current injection current value of the current harmonic source injected into the harmonic monitoring node at the current time and the historical injection current value injected into the harmonic monitoring node at the historical time.

[0008] The voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value are obtained. Based on the voltage difference and the current difference, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

[0009] In one embodiment, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference includes:

[0010] For all current harmonic sources emitting harmonics at the current time, obtain the first sum of the current value differences of all current harmonic sources, and obtain the first ratio between the current value difference of any current harmonic source and the first sum.

[0011] Obtain the first product between the first ratio corresponding to the current harmonic source and the voltage difference, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the first product and the voltage difference.

[0012] In one embodiment, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the difference between the first product value and the voltage value includes:

[0013] Based on the voltage difference, the corresponding clustering weight value of the current harmonic source is obtained;

[0014] Based on the clustering weight value and the first product value, all data collection time windows are weighted and clustered to obtain multiple time window categories;

[0015] Based on the clustering weight value and the time window category, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

[0016] In one embodiment, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the clustering weight value and the time window category includes:

[0017] Obtain the second sum of the clustering weights of all current harmonic sources under all data acquisition time windows;

[0018] For any given time window category, obtain the third sum of the clustering weights of all current harmonic sources within the data acquisition time window belonging to that time window category;

[0019] Obtain a second ratio between the third sum and the second sum, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category.

[0020] In one embodiment, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category includes:

[0021] Obtain the first influence coefficient of the harmonics emitted by the current harmonic source on any harmonic monitoring node under all data acquisition time windows;

[0022] Based on the voltage difference, the current difference, and the clustering weight, a second influence coefficient is obtained on the harmonics emitted by the current harmonic source on the harmonic monitoring node under all data acquisition time windows included in the time window category to which the current time window belongs;

[0023] Based on the second ratio, the first influence coefficient, and the second influence coefficient, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

[0024] In one embodiment, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio, the first influence coefficient, and the second influence coefficient includes:

[0025] Obtain a third ratio between the second influence coefficient and the first influence coefficient, and a second product between the second ratio and the third ratio;

[0026] The degree of influence of the current harmonic on the harmonic monitoring node is determined based on the second product value.

[0027] Secondly, this application also provides a device for determining the degree of harmonic influence, the device comprising:

[0028] The first determining module is used to determine the data acquisition time window at the current moment as the current time window when a harmonic source in the power system is detected to be emitting the current harmonic at the current moment, and to obtain the current number of times the current harmonic source emits the harmonic within the current time window for any current harmonic source emitting the current harmonic.

[0029] The second determining module is used to determine, for the previous time window before the current time window, the historical harmonics corresponding to the current number of emissions among the harmonics emitted by the current harmonic source in the previous time window, and to obtain the historical time when the current harmonic source emitted the historical harmonics.

[0030] The first acquisition module is used to acquire the current monitoring voltage value of any harmonic monitoring node at the current time and the historical monitoring voltage value at the historical time, and to acquire the current injection current value injected by the current harmonic source into the harmonic monitoring node at the current time and the historical injection current value injected into the harmonic monitoring node at the historical time.

[0031] The second acquisition module is used to acquire the voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value, and to determine the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference.

[0032] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the methods in any of the above embodiments.

[0033] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the methods in any of the above embodiments.

[0034] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps of the methods in any of the above embodiments.

[0035] The aforementioned method, apparatus, computer equipment, computer-readable storage medium, and computer program product for determining the degree of harmonic influence, when detecting the presence of a harmonic source in the power system emitting a current harmonic at the current moment, define the data acquisition time window at the current moment as the current time window, and for any harmonic source emitting a current harmonic, obtain the current emission count of the harmonic emitted by the current harmonic source within the current time window; for the previous time window preceding the current time window, determine the historical harmonics among the harmonics emitted by the current harmonic source within the previous time window that correspond to the current emission count, and obtain... The method involves obtaining the historical moment when the current harmonic source emitted historical harmonics; acquiring the current monitoring voltage value of any harmonic monitoring node at the current moment and its historical monitoring voltage value at a historical moment; acquiring the current injected current value of the current harmonic source into the harmonic monitoring node at the current moment and its historical injected current value at a historical moment; acquiring the voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value; and determining the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and current difference. The method provided in this application can accurately determine the degree of influence of harmonics on harmonic monitoring nodes, thereby accurately determining the degree of responsibility of different harmonic sources in harmonic problems, and thus reasonably managing harmonic problems. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart illustrating a method for determining the degree of harmonic influence in one embodiment;

[0038] Figure 2 This is a flowchart illustrating the steps for determining the degree of influence in one embodiment;

[0039] Figure 3 This is a schematic diagram of the equivalent circuit of the three-feeder model in another embodiment;

[0040] Figure 4 This is a structural block diagram of a device for determining the degree of harmonic influence in one embodiment;

[0041] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0044] In one embodiment, such as Figure 1 As shown, a method for determining the degree of harmonic influence is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and further to a system including both a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0045] S102. When it is detected that a harmonic source in the power system is emitting the current harmonic at the current moment, the data acquisition time window at the current moment is determined as the current time window, and for any harmonic source emitting the current harmonic, the current number of times the harmonic is emitted by the current harmonic source within the current time window is obtained.

[0046] Optionally, the current emission count h refers to the number of harmonics emitted by the current harmonic source within the current time window up to the current moment.

[0047] Optionally, during the monitoring of harmonic data in the power system, the monitoring period can be divided into multiple data acquisition time windows, and the index of the time window can be denoted as w=1, 2, ..., N, where N represents the total number of time windows within the monitoring period. The length of the data acquisition time window can be, but is not limited to, 1 min or 3 min.

[0048] S104. For the previous time window before the current time window, determine the historical harmonics corresponding to the current emission number among the harmonics emitted by the current harmonic source in the previous time window, and obtain the historical moment when the current harmonic source emitted the historical harmonics.

[0049] Optionally, historical harmonics refer to the h-th harmonic emitted by the current harmonic source in the previous time window.

[0050] S106. Obtain the current monitoring voltage value of any harmonic monitoring node at the current moment and the historical monitoring voltage value at a historical moment, and obtain the current injection current value of the current harmonic source injected into the harmonic monitoring node at the current moment and the historical injection current value of the current harmonic source injected into the harmonic monitoring node at a historical moment.

[0051] Optionally, the harmonic monitoring node may be, but is not limited to, a PCC or a user-side monitoring point.

[0052] Optionally, the monitored voltage value may be, but is not limited to, an RMS statistic, and the injected current value may be, but is not limited to, an RMS statistic.

[0053] Optionally, during the operation of the power system, the coexistence of multiple harmonic sources will cause the harmonic voltage at the PCC to fluctuate and vary with time. In order to characterize the influence of each harmonic source on the change of the harmonic level of the PCC, the monitoring data is first constructed and preprocessed.

[0054] S108. Obtain the voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injection current value and the historical injection current value, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference.

[0055] Optionally, to highlight the characteristics of harmonic disturbances caused by changes in the operation of the harmonic source, the change is constructed using a differential form of adjacent time windows. If the harmonic monitoring node is a PCC, the voltage difference can be expressed as follows:

[0056]

[0057] In the formula, Indicates the voltage difference. This indicates the current monitored voltage value. This represents the historical monitoring voltage value, w is the index of the current time window, w-1 is the index of the previous time window, and h is the current transmission count.

[0058] Alternatively, the current difference can be expressed as follows:

[0059]

[0060] In the formula, The difference in current values. The current injected current value, The historical injected current value; k is the kth harmonic source among all harmonic sources, that is, k is the current harmonic source.

[0061] Alternatively, differential operation can effectively reduce the impact of background harmonics and the slow changes in load levels and operating conditions, allowing subsequent analysis to focus more on the dynamic changes caused by harmonic sources.

[0062] In the above method for determining the degree of harmonic impact, when a harmonic source in the power system is detected emitting the current harmonic at the current moment, the data acquisition time window at the current moment is determined as the current time window. For any harmonic source emitting the current harmonic, the current emission count of the harmonic emitted by the current harmonic source within the current time window is obtained. For the previous time window before the current time window, the historical harmonics corresponding to the current emission count among the harmonics emitted by the current harmonic source in the previous time window are determined, and the historical time when the current harmonic source emitted the historical harmonics is obtained. The current monitoring voltage value of any harmonic monitoring node at the current moment and the historical monitoring voltage value at the historical time are obtained. The current injected current value of the harmonic source into the harmonic monitoring node at the current moment and the historical injected current value into the harmonic monitoring node at the historical time are also obtained. The voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value are obtained. The degree of impact of the current harmonic on the harmonic monitoring node is determined based on the voltage difference and the current difference. The method provided in this application can accurately determine the degree of influence of harmonics on harmonic monitoring nodes, thereby accurately determining the degree of responsibility of different harmonic sources in harmonic problems, and thus reasonably managing harmonic problems.

[0063] In some embodiments, such as Figure 2 As shown, the degree of influence of the current harmonic on the harmonic monitoring node is determined based on the voltage and current differences, including:

[0064] S202. For all current harmonic sources that emit harmonics at the current moment, obtain the first sum of the current value differences of all current harmonic sources, and obtain the first ratio between the current value difference of any current harmonic source and the first sum.

[0065] S204. Obtain the first product between the first ratio of the current harmonic source and the voltage difference, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the first product and the voltage difference.

[0066] Optionally, under phase-free conditions, to characterize the relative impact of different harmonic source variations on the system, a non-negative share feature is introduced; the first ratio between the current difference of any current source and the first sum is the non-negative share of the change injected by the k-th harmonic source under time windows w and h; the first ratio can be expressed as follows:

[0067]

[0068] In the formula, Let δ be the first sum of the differences in the current values ​​corresponding to all current harmonic sources, K be the total number of all harmonic sources, and δ be a very small positive number to prevent the denominator from being zero.

[0069] Optionally, the proportions of all harmonic sources are used to form an eigenvector, which reflects the relative proportion of each harmonic source injection change to the system within the time window w. This eigenvector is shown in the following equation:

[0070]

[0071] Optionally, to measure the significance of the PCC harmonic response within time window w and to distinguish between different time windows, a response intensity index based on root mean square normalization is introduced to normalize the voltage difference, as shown in the following formula:

[0072]

[0073] In the formula, This represents the difference in voltage values ​​after normalization.

[0074] Optionally, the harmonic source injection variation structure is combined with the PCC response significance to construct clustering features for operating condition classification, that is, to obtain the first product between the first ratio corresponding to the current harmonic source and the voltage value difference, as shown in the following formula:

[0075]

[0076] Optionally, to eliminate dimensional differences, f(w) is normalized to 0-1 to eliminate dimensional differences at different nodes, as shown in the following equation:

[0077]

[0078] In this embodiment, the PCC voltage difference (global harmonic disturbance) is assigned to a single harmonic source by weighting the ratio of the current difference of each harmonic source to the total current difference. This accurately quantifies the actual harmonic contribution of each harmonic source to the monitoring node and avoids the judgment bias of using only voltage or current as a single indicator.

[0079] In some embodiments, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the first product value and the voltage difference includes: obtaining the corresponding clustering weight value of the current harmonic source based on the voltage difference; performing weighted clustering on all data acquisition time windows based on the clustering weight value and the first product value to obtain multiple time window categories; and determining the degree of influence of the current harmonic on the harmonic monitoring node based on the clustering weight value and the time window category.

[0080] Optionally, since the power grid operating status is affected by factors such as changes in load level, operating mode and control strategy, the propagation coupling characteristics of harmonics may vary significantly in different time periods. If a unified responsibility decomposition is performed directly across the entire time scale, it may easily lead to the overlap of different coupling mechanisms. Therefore, this embodiment performs clustering division of time windows.

[0081] Optionally, the process of obtaining the cluster weight values ​​is shown in the following formula:

[0082]

[0083] In the formula, These are the clustering weight values; This is the weight adjustment coefficient, used to adjust the cluster weight values. The extent of the impact on clustering and liability estimation It can be, but is not limited to, within the range of 0.5-3. If , it means that no sample weighting is introduced, and the samples in each time window participate in clustering and liability estimation with equal weight.

[0084] Optionally, to give greater weight to the time windows with significant harmonic responses in the operating condition classification, the following weighted clustering objective function can be used to perform weighted clustering on all time windows:

[0085]

[0086]

[0087]

[0088] In the formula, Ω is the index set of all data acquisition time windows, Ω={1, 2, ..., N}, and C is the total number of time window categories. Let c be the set of indices for data acquisition time windows under any given time window category. Let c be the center vector of the c-th time window category.

[0089] In this embodiment, clustering weights are adaptively generated based on voltage differences to highlight time windows where harmonic disturbances are significant, thereby improving the accuracy of operating condition classification. By combining the influence of weights and categories, the results are more stable, more interpretable, and adaptable to multi-harmonic source scenarios.

[0090] In some embodiments, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the clustering weight value and the time window category includes: obtaining a second sum of the corresponding clustering weight values ​​of all current harmonic sources under all data acquisition time windows; for any time window category, obtaining a third sum of the corresponding clustering weight values ​​of all current harmonic sources under the data acquisition time window belonging to the time window category; obtaining a second ratio between the third sum and the second sum, and determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category.

[0091] Optionally, the second ratio represents the weight of the c-th time window category within the monitoring period. The second ratio reflects the significance of the time window category and harmonic disturbances, and can be expressed as follows:

[0092]

[0093] In the formula, The third sum, This is the second sum.

[0094] In this embodiment, weighted statistics are performed according to time window categories to distinguish the harmonic contributions under different time windows, and the results are more in line with the actual power grid characteristics. Based on clustering categories and weighted calculations, the interference of operating condition fluctuations is reduced, and the stability and robustness of the results are improved.

[0095] In some embodiments, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category includes: obtaining a first degree of influence coefficient of the harmonic emitted by the current harmonic source on any harmonic monitoring node under all data acquisition time windows; obtaining a second degree of influence coefficient of the harmonic emitted by the current harmonic source on the harmonic monitoring node under all data acquisition time windows included in the time window category to which the current time window belongs, based on the voltage difference, current difference, and clustering weight value; and determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio, the first degree of influence coefficient, and the second degree of influence coefficient.

[0096] Alternatively, the second degree of influence coefficient can be estimated using a weighted nonnegative least squares model, as shown in the following equation:

[0097]

[0098]

[0099]

[0100] In the formula, The second influence coefficient is calculated, which is the responsibility coefficient of harmonic source k for the h-th harmonic under time window category c.

[0101] Optionally, a non-negative contribution model can be established within time window category c, as shown in the following equation:

[0102]

[0103] Optionally, to enhance the stability of the solution, a L2 regularization term can be introduced, as shown in the following equation:

[0104]

[0105] In the formula, λ≥0 is the regularization parameter.

[0106] In this embodiment, the contribution of harmonic source disturbance is comprehensively quantified from multiple dimensions by combining the joint calculation of the two-layer influence coefficient, avoiding the one-sidedness of evaluation by a single coefficient; the coefficient is calculated based on the time window category differentiation to adapt to different power grid operating conditions and improve the accuracy of harmonic influence quantification.

[0107] In some embodiments, determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio, the first influence coefficient, and the second influence coefficient includes: obtaining a third ratio between the second influence coefficient and the first influence coefficient, and a second product between the second ratio and the third ratio; and determining the degree of influence of the current harmonic on the harmonic monitoring node based on the second product.

[0108] Alternatively, the third ratio is shown in the following formula:

[0109]

[0110] In the formula, This is the coefficient representing the degree of first-order influence.

[0111] Optionally, all time window categories are weighted and summed according to their weights to obtain the initial impact value of the h-th harmonic during the entire monitoring period, as shown in the following formula:

[0112]

[0113] In the formula, The second product between the second ratio and the third ratio. This represents the initial level of influence.

[0114] Optionally, the final value of the influence of the current harmonic on the harmonic monitoring node is shown in the following formula:

[0115]

[0116] In the formula, This represents the final value indicating the degree of influence.

[0117] Optionally, the final output includes the responsibility ratio of each harmonic source under the h-th harmonic. The results of the ranking can be used for harmonic liability determination, governance decisions, and operational evaluation.

[0118] In this embodiment, the harmonic characteristics of the global and time window categories are integrated through multi-layer ratio and product coupling calculation, and the quantification dimension of harmonic influence is refined. The calculation logic is simple and regular, suppressing random fluctuations of the power grid and steady-state background interference, and enhancing the stability and robustness of the results.

[0119] In one exemplary embodiment, another method for determining the degree of harmonic influence is provided, the method comprising the following:

[0120] This embodiment uses a typical three-feeder equivalent circuit model as an example, and builds a system on the MATLAB / Simulink platform as follows: Figure 3 The three-feeder multi-harmonic source system shown is used to analyze and compare the harmonic responsibility under a single harmonic order.

[0121] The PCC (Power Control Center) connects three user-side feeders and one system-side background branch. Harmonic currents may be injected into each feeder and the system side, creating a multi-harmonic source operating scenario. A power quality monitoring device is installed at the PCC to collect the effective values ​​of the h-th harmonic voltage and the h-th harmonic current injected into each feeder. This embodiment uses the 7th harmonic as an example for illustration.

[0122] The observation period is divided into equal-length windows, with time window indices w=1, 2, ..., 160, where 160 represents the total number of time windows within the entire observation period. There are three feeders, designated as Feeder 1, Feeder 2, and Feeder 3. There is one system-side background branch. The PCC equivalent harmonic impedance varies segmentally within the observation period, set to 2+3j for the first 80 time windows and 4+5j for the last 80 time windows. The system-side background harmonic source is equivalent to the 7th harmonic current source, whose effective harmonic current value varies stepwise within the observation period according to the time windows, specifically [6, 12, 6, 12] within the time window intervals [0~40, 41~80, 81~120, 121~160]. The effective value of the 7th harmonic current of each feeder exhibits random fluctuation characteristics with load changes, used to simulate actual operating conditions. The average harmonic current of each feeder in different operating scenarios is set as follows, with random disturbances not exceeding ±10% of the average: In operating scenario 1, feeders 1 / 2 / 3 are 8A, 6A, and 10A respectively; in operating scenario 2, feeders 1 / 2 / 3 are 12A, 5A, and 9A respectively; in operating scenario 3, feeders 1 / 2 / 3 are 7A, 9A, and 11A respectively; and in operating scenario 4, feeders 1 / 2 / 3 are 10A, 6A, and 12A respectively.

[0123] According to the method described in the specific embodiment of the present invention, the time window within the observation period is first characterized. The feature vector consists of the change in the 7th harmonic voltage at the PCC and the change in the 7th harmonic current of each branch, and is then normalized.

[0124] Based on the above characteristics, cluster analysis was performed on all time window samples. The number of operating conditions was set to C=4 during the clustering process. The clustering results divided the time windows within the observation period into four operating conditions, with relatively consistent harmonic propagation characteristics and coupling relationships within each operating condition. Considering the segmented changes in system parameters, the time window ranges corresponding to the four operating conditions are as follows:

[0125] Running scenario 1: w=1~40; Running scenario 2: w=41~80; Running scenario 3: w=81~120; Running scenario 4: w=121~160.

[0126] The above-mentioned division of operating scenarios ensures that the system's equivalent harmonic impedance and background harmonic injection level remain relatively stable in each scenario, meeting the prerequisite for independently carrying out harmonic liability calculations within the operating conditions.

[0127] In each operating scenario, the responsibility share of feeder 1, feeder 2, feeder 3 and system-side background branch for the 7th harmonic voltage of PCC is calculated according to the non-negative constraint contribution decomposition model given in the specific embodiments of the present invention.

[0128] The following parameters are set during the liability calculation process:

[0129] Time window weight η(w): Calculated from the harmonic response significance index, used to reflect the importance of different time windows to the liability calculation;

[0130] Operating condition weighting adjustment coefficient ρ: with a value of 0.5, used to balance the duration ratio of each operating condition with the severity of harmonics;

[0131] Constraints: All responsibility coefficients must satisfy the non-negativity constraint to avoid responsibility distortion caused by the mutual cancellation of contributions from multiple harmonic sources.

[0132] After obtaining the responsibility coefficients for each operating scenario, the results were normalized so that the sum of the responsibility shares within the same operating scenario was 100%. The final responsibility allocation results for multiple harmonic sources in each operating scenario were obtained. The calculation results are shown in Table 1.

[0133] Table 1

[0134]

[0135] As shown in Table 1, the harmonic responsibility allocation results obtained by the method of the present invention under different operating scenarios are generally consistent with the theoretical reference values, and the responsibility ranking remains unchanged, indicating that the method conforms to the basic electrical mechanism. Furthermore, the method of the present invention can stably output responsibility allocation results that satisfy non-negativity and additivity in various operating conditions, and achieves accurate assessment of the responsibility of multiple harmonic sources throughout the entire observation period through weighted summarization of operating conditions, providing a reliable basis for harmonic responsibility identification, over-limit control, and operational decision-making.

[0136] It should be understood that although the steps in the flowcharts of the embodiments described above 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 flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0137] Based on the same inventive concept, this application also provides a harmonic influence degree determination device for implementing the harmonic influence degree determination method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the harmonic influence degree determination device provided below can be found in the limitations of the harmonic influence degree determination method described above, and will not be repeated here.

[0138] In one exemplary embodiment, such as Figure 4 As shown, a harmonic influence degree determination device 400 is provided, including: a first determination module 401, a second determination module 402, a first acquisition module 403, and a second acquisition module 404, wherein:

[0139] The first determining module 401 is used to determine the data acquisition time window at the current moment as the current time window when a harmonic source in the power system is detected to be emitting the current harmonic at the current moment, and to obtain the current number of times the current harmonic source emits the harmonic within the current time window for any current harmonic source emitting the current harmonic.

[0140] The second determining module 402 is used to determine, for the previous time window before the current time window, the historical harmonics corresponding to the current emission number among the harmonics emitted by the current harmonic source in the previous time window, and to obtain the historical moment when the current harmonic source emitted the historical harmonics.

[0141] The first acquisition module 403 is used to acquire the current monitoring voltage value of any harmonic monitoring node at the current time and the historical monitoring voltage value at the historical time, and to acquire the current injection current value injected by the current harmonic source into the harmonic monitoring node at the current time and the historical injection current value injected into the harmonic monitoring node at the historical time.

[0142] The second acquisition module 404 is used to acquire the voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value, and to determine the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference.

[0143] In some embodiments, the second acquisition module 404 is further configured to acquire, for all current harmonic sources emitting harmonics at the current time, a first sum of the current value differences corresponding to all current harmonic sources, and acquire a first ratio between the current value difference corresponding to any current harmonic source and the first sum; acquire a first product between the first ratio corresponding to the current harmonic source and the voltage value difference, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the first product and the voltage value difference.

[0144] In some embodiments, the second acquisition module 404 is further configured to acquire the clustering weight value corresponding to the current harmonic source based on the voltage difference; perform weighted clustering on all data acquisition time windows based on the clustering weight value and the first product value to obtain multiple time window categories; and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the clustering weight value and the time window category.

[0145] In some embodiments, the second acquisition module 404 is further configured to acquire a second sum of the clustering weight values ​​of all current harmonic sources under all data acquisition time windows; for any time window category, acquire a third sum of the clustering weight values ​​of all current harmonic sources under the data acquisition time window belonging to the time window category; acquire a second ratio between the third sum and the second sum, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category.

[0146] In some embodiments, the second acquisition module 404 is further configured to acquire a first influence coefficient of the harmonic emitted by the current harmonic source on any harmonic monitoring node under all data acquisition time windows; based on the voltage difference, the current difference, and the clustering weight value, acquire a second influence coefficient of the harmonic emitted by the current harmonic source on the harmonic monitoring node under all data acquisition time windows included in the time window category to which the current time window belongs; and determine the influence degree of the current harmonic on the harmonic monitoring node based on the second ratio, the first influence coefficient, and the second influence coefficient.

[0147] In some embodiments, the second acquisition module 404 is further configured to acquire a third ratio between the second influence degree coefficient and the first influence degree coefficient, and a second product between the second ratio and the third ratio; and determine the influence degree value of the current harmonic on the harmonic monitoring node based on the second product.

[0148] The modules in the aforementioned harmonic influence determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0149] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for determining the degree of harmonic influence.

[0150] Those skilled in the art will understand that Figure 5The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0151] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0152] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0153] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0154] 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, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0155] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0156] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0157] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for determining the degree of harmonic influence, characterized in that, The method includes: If a harmonic source in the power system is detected emitting a current harmonic at the current moment, the data acquisition time window in which the current moment is located is determined as the current time window, and for any current harmonic source emitting a current harmonic, the current number of times the current harmonic source emits the harmonic within the current time window is obtained; For the previous time window before the current time window, determine the historical harmonics corresponding to the current emission number among the harmonics emitted by the current harmonic source in the previous time window, and obtain the historical moment when the current harmonic source emitted the historical harmonics; Obtain the current monitoring voltage value of any harmonic monitoring node at the current time and the historical monitoring voltage value at the historical time; and obtain the current injection current value of the current harmonic source injected into the harmonic monitoring node at the current time and the historical injection current value injected into the harmonic monitoring node at the historical time. The voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value are obtained. Based on the voltage difference and the current difference, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

2. The method according to claim 1, characterized in that, The determination of the impact of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference includes: For all current harmonic sources emitting harmonics at the current time, obtain the first sum of the current value differences of all current harmonic sources, and obtain the first ratio between the current value difference of any current harmonic source and the first sum. Obtain the first product between the first ratio corresponding to the current harmonic source and the voltage difference, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the first product and the voltage difference.

3. The method according to claim 2, characterized in that, The step of determining the degree of influence of the current harmonic on the harmonic monitoring node based on the difference between the first product value and the voltage value includes: Based on the voltage difference, the corresponding clustering weight value of the current harmonic source is obtained; Based on the clustering weight value and the first product value, all data collection time windows are weighted and clustered to obtain multiple time window categories; Based on the clustering weight value and the time window category, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

4. The method according to claim 3, characterized in that, The step of determining the degree of influence of the current harmonic on the harmonic monitoring node based on the clustering weight value and the time window category includes: Obtain the second sum of the clustering weights of all current harmonic sources under all data acquisition time windows; For any given time window category, obtain the third sum of the clustering weights of all current harmonic sources within the data acquisition time window belonging to that time window category; Obtain a second ratio between the third sum and the second sum, and determine the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category.

5. The method according to claim 4, characterized in that, The determination of the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio and the time window category includes: Obtain the first influence coefficient of the harmonics emitted by the current harmonic source on any harmonic monitoring node under all data acquisition time windows; Based on the voltage difference, the current difference, and the clustering weight, a second influence coefficient is obtained on the harmonics emitted by the current harmonic source on the harmonic monitoring node under all data acquisition time windows included in the time window category to which the current time window belongs; Based on the second ratio, the first influence coefficient, and the second influence coefficient, the degree of influence of the current harmonic on the harmonic monitoring node is determined.

6. The method according to claim 5, characterized in that, The determination of the degree of influence of the current harmonic on the harmonic monitoring node based on the second ratio, the first influence coefficient, and the second influence coefficient includes: Obtain a third ratio between the second influence coefficient and the first influence coefficient, and a second product between the second ratio and the third ratio; The degree of influence of the current harmonic on the harmonic monitoring node is determined based on the second product value.

7. A device for determining the degree of harmonic influence, characterized in that, The device includes: The first determining module is used to determine the data acquisition time window at the current moment as the current time window when a harmonic source in the power system is detected to be emitting the current harmonic at the current moment, and to obtain the current number of times the current harmonic source emits the harmonic within the current time window for any current harmonic source emitting the current harmonic. The second determining module is used to determine, for the previous time window before the current time window, the historical harmonics corresponding to the current number of emissions among the harmonics emitted by the current harmonic source in the previous time window, and to obtain the historical time when the current harmonic source emitted the historical harmonics. The first acquisition module is used to acquire the current monitoring voltage value of any harmonic monitoring node at the current time and the historical monitoring voltage value at the historical time, and to acquire the current injection current value injected by the current harmonic source into the harmonic monitoring node at the current time and the historical injection current value injected into the harmonic monitoring node at the historical time. The second acquisition module is used to acquire the voltage difference between the current monitoring voltage value and the historical monitoring voltage value, and the current difference between the current injected current value and the historical injected current value, and to determine the degree of influence of the current harmonic on the harmonic monitoring node based on the voltage difference and the current difference.

8. 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 method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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