Harmonic wave responsibility division method and device of alternating-current and direct-current hybrid system, computer equipment, storage medium and computer program product

Abstract

The invention relates to a harmonic wave responsibility division method and device of an AC-DC hybrid system, computer equipment, a storage medium and a computer program product. Relates to the technical field of power systems. The method comprises the following steps: acquiring a first harmonic voltage sequence corresponding to a common connection point in an AC / DC hybrid system, and determining an operation condition corresponding to each harmonic voltage; for each operation condition, determining the harmonic impedance of the operation condition based on the background harmonic wave corresponding to the operation condition, the harmonic current corresponding to the operation condition and the first harmonic voltage corresponding to the operation condition in the first harmonic voltage sequence; based on the harmonic impedance and a pre-obtained harmonic responsibility definition formula, obtaining harmonic responsibility corresponding to the operation condition; and determining the harmonic wave severity corresponding to the operation condition, and based on the harmonic wave responsibility and the harmonic wave severity, obtaining the target harmonic wave responsibility of the AC feeder line corresponding to the operation condition under the long time scale. By adopting the method, the accuracy of the harmonic wave responsibility division method of the alternating-current and direct-current hybrid system can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method, apparatus, computer equipment, storage medium, and computer program product for dividing harmonic responsibilities in an AC / DC hybrid system. Background Art

[0002] The development of high-voltage direct current (HVDC) transmission technology has expanded the scale of AC / DC hybrid power systems, but it has also led to the generation of characteristic and non-characteristic harmonics on both the AC and DC sides, seriously threatening the safe operation of power systems. Therefore, accurately allocating harmonic responsibilities in AC / DC hybrid systems has become an unresolved issue.

[0003] Most current harmonic responsibility allocation methods fail to consider the impact of long-term changes in harmonic source operating conditions. Furthermore, methods that consider operating condition allocation rely on DBSCAN (Density-Based Spatial Clustering of Applications with Noise) clustering, but clustering cannot capture the changing trends of harmonic data over long timescales. Furthermore, most existing harmonic responsibility allocation methods directly weight each operating condition, ignoring the differences in harmonic severity over long timescales. This results in harmonic responsibility allocation results that fail to accurately reflect the actual harmonic impact. Therefore, existing harmonic responsibility allocation methods for AC / DC hybrid systems suffer from low accuracy. Summary of the Invention

[0004] Based on this, it is necessary to address the technical problem of low accuracy in the harmonic responsibility division method of the above-mentioned AC / DC hybrid system, and provide a harmonic responsibility division method, device, computer equipment, computer-readable storage medium and computer program product for an AC / DC hybrid system.

[0005] In a first aspect, the present application provides a method for dividing harmonic responsibilities in an AC / DC hybrid system, comprising:

[0006] Obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system;

[0007] determining, according to the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence;

[0008] For each operating condition, determining the harmonic impedance of the operating condition based on a background harmonic corresponding to the operating condition, a harmonic current corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence;

[0009] Obtaining a harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula;

[0010] A harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, a target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale is obtained.

[0011] In one embodiment, determining the operating conditions corresponding to each harmonic voltage based on the first harmonic voltage sequence includes: obtaining a turning point corresponding to the first harmonic voltage in the first harmonic voltage sequence; obtaining an absolute angle value of a trend segment feature corresponding to the first harmonic voltage based on the turning point corresponding to the first harmonic voltage, and determining an absolute angle change based on the absolute angle value; and determining the operating condition corresponding to the first harmonic voltage based on the absolute angle change.

[0012] In one embodiment, obtaining the turning point corresponding to the first harmonic voltage includes: determining multiple absolute angles of the data change trend in the first harmonic voltage sequence based on the first harmonic voltage sequence, and determining multiple change characteristics of the first harmonic voltage sequence based on the multiple absolute angles; based on the multiple change characteristics, obtaining a turning point corresponding to a single change characteristic that matches the first harmonic voltage in the first harmonic voltage sequence, and determining the trend segment characteristics corresponding to the first harmonic voltage based on the turning point.

[0013] In one embodiment, when the background harmonics corresponding to the operating condition are obtained, the harmonic impedance of the operating condition is determined based on the background harmonics and in combination with the harmonic current corresponding to the operating condition and the first harmonic voltage in the first harmonic voltage sequence, including: obtaining a regression coefficient based on the background harmonics, the harmonic current and the first harmonic voltage; and determining the regression coefficient as the harmonic impedance of the operating condition.

[0014] In one embodiment, obtaining the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula includes: obtaining a cosine value of an angle between a first harmonic voltage modulus of the AC feeder and a second harmonic voltage modulus of the common connection point; and determining the harmonic responsibility based on the first harmonic voltage modulus of the AC feeder, the second harmonic voltage modulus of the common connection point, the harmonic impedance modulus of the AC feeder, the harmonic current modulus of the AC feeder, and the cosine value.

[0015] In one embodiment, determining the severity of harmonics corresponding to the operating condition includes: establishing an intuitive fuzzy judgment matrix corresponding to the operating condition; and determining the severity of harmonics corresponding to the operating condition based on the intuitive fuzzy judgment matrix and preset intuitive fuzzy table rules.

[0016] In a second aspect, the present application further provides a harmonic responsibility division device for an AC / DC hybrid system, comprising:

[0017] A harmonic voltage sequence acquisition module is used to obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system;

[0018] an operating condition determining module, configured to determine, based on the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence;

[0019] a harmonic impedance determination module, configured to determine, for each operating condition, the harmonic impedance of the operating condition based on background harmonics corresponding to the operating condition, harmonic currents corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence;

[0020] A harmonic responsibility acquisition module, configured to obtain the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula;

[0021] The harmonic responsibility acquisition module is further used to determine the harmonic severity corresponding to the operating condition, and based on the harmonic responsibility and the harmonic severity, obtain the target harmonic responsibility of the AC feeder corresponding to the operating condition on a long time scale.

[0022] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0023] Obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system;

[0024] determining, according to the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence;

[0025] For each operating condition, determining a harmonic impedance of the operating condition based on a background harmonic corresponding to the operating condition, a harmonic current corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence;

[0026] Obtaining a harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula;

[0027] A harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, a target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale is obtained.

[0028] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the following steps:

[0029] Obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system;

[0030] determining, according to the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence;

[0031] For each operating condition, determining the harmonic impedance of the operating condition based on a background harmonic corresponding to the operating condition, a harmonic current corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence;

[0032] Obtaining a harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula;

[0033] A harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, a target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale is obtained.

[0034] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the following steps:

[0035] Obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system;

[0036] determining, according to the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence;

[0037] For each operating condition, determining the harmonic impedance of the operating condition based on a background harmonic corresponding to the operating condition, a harmonic current corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence;

[0038] Obtaining a harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula;

[0039] A harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, a target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale is obtained.

[0040] The above-mentioned method, device, computer equipment, storage medium and computer program product for dividing the harmonic responsibility of the AC / DC hybrid system, in the process of dividing the harmonic responsibility of the AC / DC hybrid system, first obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system; then, based on the first harmonic voltage sequence, determine the operating conditions corresponding to each harmonic voltage in the first harmonic voltage sequence; then, for each operating condition, determine the harmonic impedance of the operating condition based on the background harmonic corresponding to the operating condition, the harmonic current corresponding to the operating condition and the first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence; then, based on the harmonic impedance of the operating condition and the pre-acquired harmonic responsibility definition formula, obtain the harmonic responsibility corresponding to the operating condition; finally, determine the harmonic severity corresponding to the operating condition, and based on the harmonic responsibility and harmonic severity, obtain the target harmonic responsibility of the AC feeder corresponding to the operating condition on a long time scale. In the above process, by analyzing the first harmonic voltage sequence, the operating conditions corresponding to different harmonic voltages can be accurately identified. When the background harmonics corresponding to the operating conditions are obtained, the harmonic impedance is calculated in combination with the harmonic current and the first harmonic voltage, which can more accurately reflect the dynamic characteristics of the AC / DC hybrid system and improve the calculation accuracy of the harmonic impedance. Moreover, by combining the calculated harmonic impedance with the pre-defined harmonic responsibility formula, the harmonic responsibility of each operating condition can be more accurately evaluated. Therefore, the systematic and comprehensive analysis process in the above process improves the accuracy of the harmonic responsibility division method of the AC / DC hybrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 1 is a flow chart of a method for dividing harmonic responsibilities in an AC / DC hybrid system according to an embodiment;

[0043] Figure 2 1. A schematic flow chart of the steps for dividing harmonic responsibilities of an AC / DC hybrid system in one embodiment;

[0044] Figure 3 A circuit diagram of a multi-harmonic source connected to an equivalent circuit in one embodiment;

[0045] Figure 4 A schematic diagram of a measured long-time-scale harmonic voltage variation trend in one embodiment;

[0046] Figure 5 A structural block diagram of a harmonic responsibility division device for an AC / DC hybrid system in one embodiment;

[0047] Figure 6 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0048] The development of high-voltage direct current (HVDC) transmission technology has, on the one hand, expanded the scale of AC / DC hybrid systems. On the other hand, the characteristic and non-characteristic harmonics generated on the AC and DC sides pose a serious threat to the safe operation of power systems. Therefore, accurately dividing the harmonic responsibilities at the AC / DC grid connection point can provide an effective basis for harmonic management of AC / DC hybrid systems and the formulation of harmonic reward and punishment schemes. However, the harmonic responsibility division results of existing harmonic responsibility division methods often overwhelm the actual harmonic impact. In the operating condition division research, DBSCAN (Density-Based Spatial Clustering of Applications with Noise) was used to divide the operating conditions. However, the changing trend characteristics of the harmonic sampling data over long time scales cannot be presented through clustering. In addition, most existing harmonic responsibility division methods directly weight each operating condition, ignoring the differences in harmonic severity over long time scales and failing to accurately characterize the actual harmonic impact.

[0049] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0050] In one embodiment, Figure 1 As shown, a method for allocating harmonic responsibilities in an AC / DC hybrid system is provided. This embodiment uses the method applied to a terminal as an example for illustration. It is understood that the method can also be applied to a server, or to a system including a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0051] Step S102: obtaining a first harmonic voltage sequence corresponding to a common connection point in the AC / DC hybrid system.

[0052] Among them, the common connection point refers to the PCC (Point of Common Coupling), which is usually the intersection of multiple users or equipment in the power system; the first harmonic voltage sequence refers to the voltage signal sequence recorded within a specific time period.

[0053] Step S104: determining an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence according to the first harmonic voltage sequence.

[0054] Among them, operating conditions refer to the operating status of equipment or AC / DC hybrid systems under specific conditions, including load type, load degree, load change, etc.

[0055] As an example, multiple harmonic voltages in the first harmonic voltage sequence are obtained, and signal processing is performed on one of the harmonic voltages, which may be feature extraction. The extracted features are compared with predefined operating condition standards to determine the operating condition corresponding to the above harmonic voltage. For example, if it is identified that the voltage continues to rise over a period of time, it can be indicated that the operating condition is high load.

[0056] Step S106 , for each operating condition, determining the harmonic impedance of the operating condition based on the background harmonics corresponding to the operating condition, the harmonic current corresponding to the operating condition, and the first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence.

[0057] Among them, background harmonics refer to the harmonic frequency components of the AC / DC hybrid power system under specific operating conditions; harmonic current refers to the frequency components other than the fundamental component in the current waveform caused by nonlinear loads; the first harmonic voltage refers to one of the voltages in the first harmonic voltage sequence; and harmonic impedance refers to the ratio of harmonic current to the first harmonic voltage.

[0058] Step S108 : obtaining the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and the pre-acquired harmonic responsibility definition formula.

[0059] Among them, harmonic responsibility can be the contribution of a specific device or load to the harmonic current or first harmonic voltage under a certain operating condition. The harmonic responsibility definition is usually a mathematical formula used to calculate the contribution of the harmonic current or first harmonic voltage in a specific device or load, usually involving the relationship between the harmonic impedance and the harmonic current or first harmonic voltage generated by the device.

[0060] Step S110 , determining the harmonic severity corresponding to the operating condition, and obtaining a target harmonic responsibility of the AC feeder corresponding to the operating condition in a long time scale based on the harmonic responsibility and the harmonic severity.

[0061] Among them, harmonic severity is an indicator to measure the impact of harmonic pollution in the power system, which can be defined based on the amplitude and frequency of harmonic current or first harmonic voltage; long time scale refers to the analysis of the operating status of the AC / DC hybrid system over a long period of time, such as several hours, days or longer; target harmonic responsibility refers to the harmonic responsibility division result of the AC / DC hybrid system obtained under specific operating conditions based on the analysis of harmonic severity and harmonic responsibility.

[0062] In the above-mentioned harmonic responsibility division method of the AC / DC hybrid system, in the process of harmonic responsibility division of the AC / DC hybrid system, the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system is first obtained; then, based on the first harmonic voltage sequence, the operating conditions corresponding to each harmonic voltage in the first harmonic voltage sequence are determined; then, for each operating condition, the harmonic impedance of the operating condition is determined based on the background harmonic corresponding to the operating condition, the harmonic current corresponding to the operating condition, and the first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence; then, based on the harmonic impedance of the operating condition and the pre-acquired harmonic responsibility definition formula, the harmonic responsibility corresponding to the operating condition is obtained; finally, the harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, the target harmonic responsibility of the AC feeder corresponding to the operating condition on a long time scale is obtained. In the above process, by analyzing the first harmonic voltage sequence, the operating conditions corresponding to different harmonic voltages can be accurately identified. When the background harmonics corresponding to the operating conditions are obtained, the harmonic impedance is calculated in combination with the harmonic current and the first harmonic voltage, which can more accurately reflect the dynamic characteristics of the AC / DC hybrid system and improve the calculation accuracy of the harmonic impedance. Moreover, by combining the calculated harmonic impedance with the pre-defined harmonic responsibility formula, the harmonic responsibility of each operating condition can be more accurately evaluated. Therefore, the systematic and comprehensive analysis process in the above process improves the accuracy of the harmonic responsibility division method of the AC / DC hybrid system.

[0063] In an exemplary embodiment, determining the operating conditions corresponding to each harmonic voltage according to the first harmonic voltage sequence includes:

[0064] Obtain a turning point corresponding to a first harmonic voltage in a first harmonic voltage sequence; obtain an absolute angle value of a trend segment characteristic corresponding to the first harmonic voltage based on the turning point corresponding to the first harmonic voltage, and determine an absolute angle change based on the absolute angle value; and determine an operating condition corresponding to the first harmonic voltage based on the absolute angle change.

[0065] The absolute angle change can be the change amplitude of the absolute angle value between different trend segments. The absolute angle change can be obtained by comparing the absolute angle values of adjacent trend segments, which can reflect the amplitude, speed and specific operating characteristics of the first harmonic voltage change.

[0066] As an example, the corresponding operating condition can be determined based on the obtained absolute angle change. If the absolute angle change is large, it may mean that the operating condition of the AC / DC hybrid system is changing rapidly, and attention should be paid to its stability.

[0067] In this embodiment, by analyzing the absolute angle variation, the future trend of the first harmonic voltage sequence can be predicted, thereby providing decision support for load scheduling and power management.

[0068] Furthermore, in one embodiment, before determining the operating conditions corresponding to the respective harmonic voltages according to the first harmonic voltage sequence, the method further includes:

[0069] Based on the first harmonic voltage sequence, multiple absolute angles of the data change trend in the first harmonic voltage sequence are determined, and based on the multiple absolute angles, multiple change characteristics of the first harmonic voltage sequence are determined; based on the multiple change characteristics, a turning point corresponding to a single change characteristic matching the first harmonic voltage in the first harmonic voltage sequence is obtained, and based on the turning point, a trend segment characteristic corresponding to the first harmonic voltage is determined.

[0070] Among them, the data change trend refers to the rise, fall or stability of the data value within a certain time range; the absolute angle can be to analyze the data change trend from multiple dimensions, such as evaluating the changes in the first harmonic voltage sequence from multiple aspects such as time, amplitude, frequency, etc.; the change characteristics can be key indicators or parameters reflecting the changes in the data sequence, such as peak value, valley value, average value, rate of change, etc.; the turning point can be the location where a significant change occurs in the first harmonic voltage sequence, which is usually manifested as a change in trend, such as from rising to falling or from falling to rising; the trend segment can be the characteristics of different trend segments divided based on the turning point.

[0071] In this embodiment, by identifying and analyzing the changing trends, turning points, and trend segment characteristics of the first harmonic voltage sequence, the dynamic changes in power quality can be fully understood. Monitoring turning points can also help detect abnormal conditions early and respond quickly, preventing equipment damage and system failures, thereby improving the reliability and safety of the AC / DC hybrid system.

[0072] In one embodiment, when background harmonics corresponding to the operating condition are obtained, determining the harmonic impedance of the operating condition based on the background harmonics and in combination with the harmonic current corresponding to the operating condition and the first harmonic voltage in the first harmonic voltage sequence includes:

[0073] A regression coefficient is obtained based on background harmonics, harmonic currents, and first harmonic voltage; and the regression coefficient is determined as the harmonic impedance of the operating condition.

[0074] The regression coefficient refers to the parameter determined in the regression analysis, which can be used to indicate how one variable affects another variable. It can also be used to indicate the degree of influence of factors such as background harmonics and harmonic currents on the first harmonic voltage, reflecting the sensitivity of the AC / DC hybrid system to changes in factors such as background harmonics, harmonic currents, and first harmonic voltage.

[0075] In this embodiment, through the above process, the AC / DC hybrid system can have a deeper understanding of the impact and behavior of harmonics, and formulate appropriate measures to reduce the interference of harmonics on the system, ensuring the safety and stability of power quality. This can not only guide the selection and configuration of equipment, but also provide support for optimizing the operation and management strategy of the AC / DC hybrid system.

[0076] In an exemplary embodiment, based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula, the harmonic responsibility corresponding to the operating condition is obtained, including:

[0077] Obtain the cosine value of the angle between the first harmonic voltage modulus of the AC feeder and the second harmonic voltage modulus of the common connection point; and determine the harmonic responsibility based on the first harmonic voltage modulus of the AC feeder, the second harmonic voltage modulus of the common connection point, the harmonic impedance modulus of the AC feeder, the harmonic current modulus of the AC feeder, and the cosine value.

[0078] The first harmonic voltage modulus of the AC feeder is the effective value or peak value of the fundamental voltage on the AC feeder, indicating the normal voltage level of the AC feeder; the second harmonic voltage modulus at the common connection point is the effective value or peak value of the second harmonic voltage measured at the connection point shared by multiple loads or devices; the cosine of the angle refers to the cosine of the phase angle between two voltage quantities and can be used to indicate the phase relationship between the voltages; and the harmonic current modulus refers to the effective value of the current caused by the harmonic load.

[0079] In this embodiment, by obtaining the cosine value of the angle between the first harmonic voltage modulus of the AC feeder and the second harmonic voltage modulus of the common connection point, it can help analyze the impact of harmonics in the AC / DC hybrid system on power quality; it can also more accurately identify and evaluate harmonic problems, and take effective measures to optimize power quality.

[0080] Furthermore, in one embodiment, determining the severity of harmonics corresponding to the operating condition includes:

[0081] An intuitive fuzzy judgment matrix corresponding to the operating condition is established; based on the intuitive fuzzy judgment matrix and preset intuitive fuzzy table rules, the severity of the harmonics corresponding to the operating condition is determined.

[0082] Among them, the intuitive fuzzy judgment matrix is a tool for decision analysis and multivariate comparison; the preset intuitive fuzzy table rules can be a set of rules or standards used in the decision-making process, which can help to clearly classify fuzzy data; the harmonic severity is an indicator to measure the impact of harmonics on power quality and equipment performance in AC / DC hybrid systems, which can include harmonic content, waveform distortion degree, etc.

[0083] In this embodiment, the above process can effectively identify and evaluate harmonic problems under different operating conditions. When it is identified that the harmonic severity of a certain operating condition is high, the manager can consider taking harmonic control measures, such as installing filters or optimizing the AC / DC hybrid system, to reduce the impact of harmonics on equipment and systems.

[0084] This application provides a method for dividing harmonic responsibilities of an AC / DC hybrid system. In order to better understand the process of the above-mentioned method for dividing harmonic responsibilities of an AC / DC hybrid system, combined with Figure 2 As shown, the following describes in detail a specific process of the harmonic responsibility division method of the AC / DC hybrid system of the present application, including the following steps:

[0085] Step S202: Acquire a harmonic sample data set.

[0086] The harmonic sample data set represents the first harmonic voltage sequence, including X={X1, X2, ...X n};

[0087] Step S204: dividing the working conditions based on the turning points and trend segments.

[0088] As an example, the working condition classification process includes quantifying the change characteristics of the time series based on the absolute angle of the data change trend for the PCC point harmonic voltage dataset. , turning point definition: ,in, Indicates the position of the point in the sequence of interest, represents the j-th turning point, The following conditions are met:

[0089]

[0090]

[0091] in, is the angle threshold, αi is the angle change value of the point, and the turning point connection line constitutes a trend segment, which represents the trend change characteristics of the time series.

[0092] More, Indicates the position of the point in the sequence of interest, represents the j-th turning point, The following conditions are met:

[0093]

[0094]

[0095]

[0096] in, is the angle threshold, αi is the angle change value of the point, the turning point connection constitutes a trend segment, and the trend segment represents the trend change characteristics of the time series; by calculating the angle change between adjacent turning points, the trend of the trend segment is measured. Indicates calculating the absolute angle value of two adjacent points, that is, converting the slope of the two points into radians. The formula is Since the obtained radians are both positive and negative, we will discuss them in categories.

[0097] In addition, for the PCC point harmonic voltage dataset , its turning point sequence can define the trend segment as: ,in, Indicates two trend points , The absolute angle value of the line segment connected between them is used to divide the final operating conditions according to the absolute angle change of the determined trend segment.

[0098] Step S206: dividing the operating conditions into long time scales.

[0099] Among them, the long-term operating conditions are divided into M1, M2, ...M3;

[0100] Step S208: Perform linear regression on each operating condition to determine the harmonic impedance.

[0101] As an example, the harmonic impedance calculation includes: using Tikhonov regularization to calculate the regression coefficient of the harmonic current of each feeder and the harmonic voltage data of the PCC point within the divided working conditions. The regression coefficient is the harmonic impedance of the AC feeder. The basic idea of Tikhonov regularization is to balance the accuracy of data fitting and the complexity of the model by introducing a regularization term to avoid overfitting or unstable solutions. Figure 3 Taking the multi-harmonic source equivalent circuit shown in the figure as an example, the regression equation is: ,in is the regression coefficient, i.e. the harmonic impedance corresponding to feeder i, is the background harmonic, is the feeder harmonic current.

[0102] Furthermore, Tikhonov regularization can be used to deal with ill-conditioned regression problems. If the multi-harmonic source equivalent circuit regression equation is: , where A is the regression coefficient matrix, x is the feeder harmonic current matrix, and b is the PCC point harmonic voltage measurement matrix. Performing singular value decomposition on the regression coefficient matrix A yields: ,in and is an orthogonal matrix, m is the matrix dimension, If A is the regression coefficient, then it is the singular value matrix; the solution vector of the regression equation of the multi-harmonic source equivalent circuit after regularization is , where is the regularization parameter, and L is the regularization matrix. When the regularization parameter is appropriate, a balance is achieved between the minimum error of data fitting and stability. At this time, the above formula is equivalent to solving the following overdetermined equation: , whose solution is of the form: , the regularization parameter Determined by the L-curve method.

[0103] Step S210 , dividing the operating harmonic responsibility according to the harmonic impedance responsibility definition.

[0104] As an example, the harmonic liability definition is:

[0105]

[0106] in, represents the hth harmonic voltage modulus (first harmonic voltage modulus) of the ith feeder, Indicates the hth harmonic voltage modulus at PCC point (second harmonic voltage modulus), express and The cosine of the angle, represents the hth harmonic impedance modulus of feeder i (the harmonic impedance modulus of AC feeder), Indicates the modulus of the hth harmonic current of feeder i (the modulus of the harmonic current of the AC feeder).

[0107] In step S212 , the severity of harmonics in each operating condition is considered, and the weight of each operating condition is determined by using the intuitive fuzzy hierarchical analysis method.

[0108] As an example, the harmonic responsibility of feeder i under various operating conditions is: ,in, Represents the harmonic responsibility under the kth operating condition.

[0109] Furthermore, the steps for calculating the harmonic severity weights of each operating condition are as follows: establishing an intuitive fuzzy complementary judgment matrix of the harmonic responsibility severity of each feeder; performing a consistency test on the intuitive fuzzy complementary judgment matrix to determine the rationality of the evaluation index; determining the weights between the various indicators based on the intuitive fuzzy judgment matrix, and determining the intuitive fuzzy judgment matrix of the evaluation indexes between each hierarchical structure based on the intuitive fuzzy table rules. The intuitive fuzzy table is shown in Table 1. , ,in, ; When comparing the importance of indicators, Indicates the decision maker's hesitation. Indicates the degree to which decision makers value i more. Indicates the degree to which the decision maker values j.

[0110] As an example, taking the less important evaluation as an example, among its intuitionistic fuzzy numbers (0.40, 0.45, 0.15), the decision maker's degree of recognition of the thing is 0.4, the decision maker's degree of disagreement of the thing is 0.45, and the decision maker's degree of suspicion of the thing is 0.15, that is, the decision maker's degree of disapproval of the thing is higher; among the extremely important intuitionistic fuzzy numbers (0.90, 0.10, 0.00), the decision maker's degree of recognition of the thing is 0.9, the decision maker's degree of disagreement of the thing is 0.1, and the decision maker's degree of suspicion of the thing is 0, that is, the decision maker fully recognizes the thing.

[0111] Table 1 Intuitionistic fuzzy table

[0112]

[0113] In addition, in order to ensure the rationality of the evaluation indicators, the fuzzy consistency matrix is used to perform consistency test on the intuitive fuzzy complementary judgment matrix. The fuzzy consistency matrix is as follows:

[0114]

[0115] in, , ,If the fuzzy consistent matrix meets the consistency requirements, it means that the ,intuitionistic fuzzy complementary judgment matrix passes the consistency test.

[0116] In addition, the weights between the indicators are calculated as follows:

[0117]

[0118] in, represents the harmonic severity weight of the kth operating condition.

[0119] In step S214, the harmonic responsibility of each operating condition is comprehensively weighted with the operation weight to obtain the comprehensive harmonic responsibility on a long time scale.

[0120] The comprehensive harmonic responsibility refers to the multiple target harmonic responsibilities corresponding to multiple AC feeders and is calculated based on the following formula: , Indicates the comprehensive harmonic responsibility, represents the transpose of the weight matrix.

[0121] In one embodiment, Figure 3 The circuit diagram of the multi-harmonic source connected to the equivalent circuit shown in the figure includes the DC side, rectification, AC / DC grid connection point and the corresponding current I pc and voltage U pcc , AC feeder 1 and the corresponding current I1 and impedance Z1, AC feeder 2 and the corresponding current I2 and impedance Z2, AC feeder 3 and the corresponding current I3 and impedance Z3.

[0122] Furthermore, in another embodiment, Figure 4 The figure shows the schematic diagram of the measured long-time harmonic voltage variation trend, including the number of sampling points and voltage.

[0123] In an exemplary embodiment, the harmonic voltage at the PCC point of the AC / DC grid and the harmonic current of each AC feeder are collected to construct an input sample data set. Based on the input sample data set, the harmonic voltage at the PCC point is divided into operating conditions using its turning point and trend segment characteristics. The Tikhonov regularization method is used to calculate the harmonic impedance for each divided condition, and the harmonic responsibility of the feeder under each operating condition is calculated using the harmonic responsibility definition formula. The intuitive fuzzy hierarchical analysis method is used to calculate the harmonic severity weight of each operating condition, and the comprehensive harmonic responsibility of each feeder on a long time scale is obtained by weighting it with the harmonic responsibility of each feeder.

[0124] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0125] Based on the same inventive concept, an embodiment of the present application further provides a harmonic responsibility division device for an AC / DC hybrid system for implementing the aforementioned method for dividing harmonic responsibility for an AC / DC hybrid system. The implementation solution provided by this device is similar to the implementation solution described in the aforementioned method. Therefore, the specific limitations in the embodiments of one or more AC / DC hybrid system harmonic responsibility division devices provided below can be found in the limitations of the AC / DC hybrid system harmonic responsibility division method described above and will not be repeated here.

[0126] In an exemplary embodiment, Figure 5 As shown, a harmonic responsibility division device for an AC / DC hybrid system is provided, comprising: a harmonic voltage sequence acquisition module 501, an operating condition determination module 502, a harmonic impedance determination module 503, and a harmonic responsibility acquisition module 504, wherein:

[0127] The harmonic voltage sequence acquisition module 501 is used to acquire the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system.

[0128] The operating condition determination module 502 is configured to determine the operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence according to the first harmonic voltage sequence.

[0129] The harmonic impedance determination module 503 is used to determine the harmonic impedance of each operating condition based on the background harmonics corresponding to the operating condition, the harmonic current corresponding to the operating condition, and the first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence.

[0130] The harmonic responsibility acquisition module 504 is configured to obtain the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula.

[0131] The harmonic responsibility acquisition module 504 is further configured to determine the harmonic severity corresponding to the operating condition, and based on the harmonic responsibility and the harmonic severity, obtain the target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale.

[0132] Furthermore, in one embodiment, the operating condition determination module 502 is also used to obtain a turning point corresponding to the first harmonic voltage in the first harmonic voltage sequence; based on the turning point corresponding to the first harmonic voltage, obtain the absolute angle value of the trend segment feature corresponding to the first harmonic voltage, and determine the absolute angle change based on the absolute angle value; based on the absolute angle change, determine the operating condition corresponding to the first harmonic voltage.

[0133] Furthermore, in one embodiment, the operating condition determination module 502 is also used to determine multiple absolute angles of the data change trend in the first harmonic voltage sequence based on the first harmonic voltage sequence, and determine multiple change characteristics of the first harmonic voltage sequence based on the multiple absolute angles; based on the multiple change characteristics, obtain a turning point corresponding to a single change characteristic matching the first harmonic voltage in the first harmonic voltage sequence, and determine the trend segment characteristics corresponding to the first harmonic voltage based on the turning point.

[0134] Furthermore, in one embodiment, the harmonic impedance determination module 503 is further configured to obtain a regression coefficient based on the background harmonics, the harmonic current, and the first harmonic voltage; and determine the regression coefficient as the harmonic impedance of the operating condition.

[0135] Furthermore, in one embodiment, the harmonic responsibility acquisition module 504 is further configured to obtain a cosine value of an angle between a first harmonic voltage modulus of the AC feeder and a second harmonic voltage modulus of the common connection point; and determine the harmonic responsibility based on the first harmonic voltage modulus of the AC feeder, the second harmonic voltage modulus of the common connection point, the harmonic impedance modulus of the AC feeder, the harmonic current modulus of the AC feeder, and the cosine value.

[0136] Furthermore, in one embodiment, the harmonic responsibility acquisition module 504 is further configured to establish an intuitionistic fuzzy judgment matrix corresponding to the operating condition; and determine the severity of the harmonics corresponding to the operating condition based on the intuitionistic fuzzy judgment matrix and preset intuitionistic fuzzy table rules.

[0137] Each module in the harmonic responsibility division device for the AC / DC hybrid system can be implemented in whole or in part via software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0138] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 6As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. 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, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store harmonic responsibility division data of an AC / DC hybrid system. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a harmonic responsibility division method for an AC / DC hybrid system is implemented.

[0139] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0140] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0141] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0142] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0143] 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, stored data, displayed data, 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 relevant data must comply with relevant regulations.

[0144] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile 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 various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0145] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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 specification.

[0146] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for dividing harmonic responsibilities in an AC / DC hybrid system, characterized in that: The method comprises: Obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system; determining, according to the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence; For each operating condition, determining the harmonic impedance of the operating condition based on a background harmonic corresponding to the operating condition, a harmonic current corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence; Obtaining a harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula; A harmonic severity corresponding to the operating condition is determined, and based on the harmonic responsibility and the harmonic severity, a target harmonic responsibility of the AC feeder corresponding to the operating condition over a long time scale is obtained.

2. The method according to claim 1, characterized in that The determining, based on the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage includes: Obtaining a turning point corresponding to a first harmonic voltage in the first harmonic voltage sequence; acquiring, based on a turning point corresponding to the first harmonic voltage, an absolute angle value of a trend segment feature corresponding to the first harmonic voltage, and determining an absolute angle change amount based on the absolute angle value; Based on the absolute angle change, the operating condition corresponding to the first harmonic voltage is determined.

3. The method according to claim 2, characterized in that The obtaining of the turning point corresponding to the first harmonic voltage includes: determining, based on the first harmonic voltage sequence, a plurality of absolute angles of a data change trend in the first harmonic voltage sequence, and determining, based on the plurality of the absolute angles, a plurality of change features of the first harmonic voltage sequence; Based on the multiple change characteristics, a turning point corresponding to a single change characteristic matching the first harmonic voltage in the first harmonic voltage sequence is obtained, and a trend segment characteristic corresponding to the first harmonic voltage is determined based on the turning point.

4. The method according to claim 1, wherein The determining, when background harmonics corresponding to the operating condition are obtained, the harmonic impedance of the operating condition based on the background harmonics and in combination with the harmonic current corresponding to the operating condition and the first harmonic voltage in the first harmonic voltage sequence, includes: A regression coefficient is obtained based on the background harmonics, the harmonic current, and the first harmonic voltage; and the regression coefficient is determined as the harmonic impedance of the operating condition.

5. The method according to claim 1, wherein The obtaining of the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula includes: Obtaining a cosine value of an angle between a first harmonic voltage modulus of the AC feeder and a second harmonic voltage modulus of the common connection point; The harmonic responsibility is determined based on a first harmonic voltage modulus of the AC feeder, a second harmonic voltage modulus of the common connection point, a harmonic impedance modulus of the AC feeder, a harmonic current modulus of the AC feeder, and the cosine value.

6. The method according to claim 1, characterized in that Determining the severity of harmonics corresponding to the operating condition includes: Establishing an intuitive fuzzy judgment matrix corresponding to the operating condition; Based on the intuitionistic fuzzy judgment matrix and preset intuitionistic fuzzy table rules, the severity of the harmonics corresponding to the operating condition is determined.

7. A harmonic responsibility division device for an AC / DC hybrid system, characterized in that: The device comprises: A harmonic voltage sequence acquisition module is used to obtain the first harmonic voltage sequence corresponding to the common connection point in the AC / DC hybrid system; an operating condition determination module, configured to determine, based on the first harmonic voltage sequence, an operating condition corresponding to each harmonic voltage in the first harmonic voltage sequence; a harmonic impedance determination module, configured to determine, for each operating condition, the harmonic impedance of the operating condition based on background harmonics corresponding to the operating condition, harmonic currents corresponding to the operating condition, and a first harmonic voltage corresponding to the operating condition in the first harmonic voltage sequence; A harmonic responsibility acquisition module, configured to obtain the harmonic responsibility corresponding to the operating condition based on the harmonic impedance of the operating condition and a pre-acquired harmonic responsibility definition formula; The harmonic responsibility acquisition module is further used to determine the harmonic severity corresponding to the operating condition, and based on the harmonic responsibility and the harmonic severity, obtain the target harmonic responsibility of the AC feeder corresponding to the operating condition on a long time scale.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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

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

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