Harmonic source positioning method and apparatus, electronic device, and storage medium

Abstract

The present application relates to the technical field of power quality treatment, and particularly relates to a harmonic source positioning method and device, electronic equipment and storage medium. The method comprises the following steps: firstly, obtaining current waveform data sets; then, according to target harmonics, performing harmonic current analysis on a plurality of feeder current waveform data queues in the current waveform data sets to obtain a plurality of harmonic current vectors and construct the harmonic current vectors into harmonic current data sets; then, according to a topology structure formed by a main power supply, a plurality of load feeders and a plurality of power supply feeders and the harmonic current data sets, constructing a harmonic voltage equation set expressing the relationship among harmonic currents, bus section harmonic impedances and harmonic voltage differences between feeders; finally, determining a harmonic source according to a plurality of bus section harmonic impedances and the plurality of harmonic current data sets. The present application is based on harmonic currents and topology structures, analyzes the harmonic current trend and harmonic impedance in the power grid, and finally determines the feeder with the largest harmonic contribution degree, so that the harmonic source positioning is more accurate.

Description

Technical Field

[0001] This invention relates to the field of power quality management technology, and in particular to a method, apparatus, electronic device and storage medium for locating harmonic sources. Background Technology

[0002] The core idea for locating harmonic sources through data analysis is to collect harmonic voltage and current time-series data from various nodes in the power distribution system, combine this data with mathematical models, signal processing, or data mining algorithms to extract harmonic characteristics and quantify harmonic propagation patterns, thereby inferring the specific location of the harmonic source. Traditional model analysis methods have significant technical advantages, but they also face unavoidable drawbacks, specifically as follows: Traditional model analysis (based on a fundamental electrical model and data fitting) is the mainstream technology for harmonic source localization. It relies on the basic electrical laws of power distribution systems (Ohm's law, power conservation, etc.) to locate harmonic sources by fitting the relationship between harmonic voltage and current data and a pre-set model. This mainly includes the following three specific methods: Harmonic power method: The core principle is to determine the location of harmonic sources based on the "harmonic power flow direction". The industry generally follows the rule that "when harmonic power flows in the forward direction (from the feeder to the load), the harmonic source is located on the load side; when it flows in the reverse direction, the harmonic source is located on the power supply side". By traversing the power flow direction at each node, the feeder or region where the harmonic source is located can be pinpointed. This method does not require complex model solving, only basic harmonic voltage and current data, has low computational load, and low engineering implementation cost, making it the most widely used early location method.

[0003] Harmonic impedance method: The core principle is to utilize the significant difference in harmonic impedance between the harmonic source side and the non-harmonic source side (typically, the harmonic impedance on the power supply side is smaller, while the harmonic impedance on the load side is larger). By analyzing data, the equivalent harmonic impedance of the system is estimated, and the harmonic source is located by combining the impedance characteristics. Common data analysis methods include linear regression and least squares methods. These methods involve collecting multiple sets of harmonic voltage and current data, fitting the system's harmonic impedance, and then distinguishing whether the harmonic source is located on the power supply side or the load side based on the impedance amplitude and phase characteristics. Some improved methods introduce harmonic impedance angles to assist in the judgment, but they still essentially rely on the data analysis and fitting of impedance parameters.

[0004] The aforementioned data analysis-based harmonic source localization methods all suffer from unavoidable drawbacks in practical engineering applications. These drawbacks include both individual limitations specific to each method and common industry-wide defects, as detailed below: The drawbacks of the harmonic power method are as follows: First, it fails to locate the source when multiple harmonic sources coexist. When multiple harmonic sources exist in a power distribution system, the harmonic power generated by different sources will superimpose and cancel each other out, leading to errors in the determination of the harmonic power flow direction and making it impossible to accurately distinguish the location of a single harmonic source. Second, it is greatly affected by the system impedance angle. When the system harmonic impedance angle is close to 90°, the calculation error of harmonic active power increases significantly, and even misjudgment of the power flow direction may occur. Third, it cannot pinpoint the specific location of the harmonic source; it can only determine whether the harmonic source is located on the power supply side or the load side, but cannot pinpoint the specific feeder or node, thus limiting its practicality. Fourth, it is sensitive to measurement errors. Measurement errors of voltage and current sensors will directly lead to deviations in harmonic power calculation, affecting the location results.

[0005] The drawbacks of the harmonic impedance method are: First, the dynamic changes in the system's harmonic impedance lead to large estimation errors. The harmonic impedance of the power distribution system changes dynamically with load changes, topology switching, and operating condition adjustments. The harmonic impedance fitted based on historical data or static models cannot match real-time operating conditions, resulting in positioning deviations. Second, the background harmonic voltage interference is large. Traditional impedance estimation methods such as linear regression will exhibit large harmonic impedance estimation errors when the background harmonic voltage fluctuates, thus affecting positioning accuracy.

[0006] Therefore, it is necessary to develop and design a method for locating harmonic sources. Summary of the Invention

[0007] The present invention provides a method, apparatus, electronic device and storage medium for locating harmonic sources, which solves the problem of large positioning deviations of harmonic sources in the prior art.

[0008] In a first aspect, embodiments of the present invention provide a method for locating harmonic sources, comprising: Acquire a current waveform dataset, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply. Harmonic current analysis is performed on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonics, and multiple harmonic current vectors are obtained to construct a harmonic current dataset. Based on the topology consisting of the main power supply, multiple load feeders, and multiple power supply feeders, and the harmonic current dataset, a set of harmonic voltage equations is constructed to express the relationship between harmonic current, bus segment harmonic impedance, and harmonic voltage difference between feeders. The harmonic source is determined based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

[0009] In one possible implementation, the harmonic current analysis is performed on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, and multiple harmonic current vectors are obtained to construct a harmonic current dataset, including: For the multiple feeder current waveform data queues in the current waveform dataset, the following steps are performed respectively: Based on the first formula, the target harmonic, and the feeder current waveform data queue, the harmonic active current and harmonic reactive current are extracted, wherein the first formula is:

[0010] In the formula, Harmonic active current, This is harmonic reactive current. Pi The harmonic order of the target harmonic. The power frequency. The number of times the current data is sampled within the target harmonic period. The first in the feeder current waveform data queue One data point, This represents the total number of data items in the feeder current waveform data queue. The sampling rate of the current waveform data queue; The harmonic active current is used as the real part, and the harmonic reactive current is used as the imaginary part to construct the harmonic current vector.

[0011] In one possible implementation, based on the topology consisting of the main power supply, multiple load feeders, and multiple power feeders, and the harmonic current dataset, a set of harmonic voltage equations expressing the relationship between harmonic current, bus segment harmonic impedance, and inter-feeder harmonic voltage difference is constructed, including: Construct multiple through current vectors, where each through current vector is a harmonic current vector originating from a power supply feeder and arriving at a load feeder or originating from the main power supply and arriving at a load feeder. Based on the relationship between the multiple through current vectors and harmonic current vectors, a through current vector equation is constructed, and the through current vector equation is added to the harmonic voltage equation set. From the plurality of load feeders and the plurality of power feeders, feeders are selected one by one as feeders to be processed, and the following steps are performed on each feeder to be processed: Based on the topology, multiple target current vectors are selected from the multiple current vectors, wherein the target current vectors pass through the target bus segment, and the feeder to be processed is connected to the rear end of the target bus segment; For the target bus segment, a target bus segment current vector is constructed based on the plurality of target through current vectors; Based on the harmonic voltage difference between feeder nodes, the harmonic impedance of the target bus segment, and the current vector of the target bus segment, a feeder harmonic voltage equation is constructed, wherein the harmonic voltage difference between feeder nodes is the voltage difference between the current feeder node and the previous feeder node. Add the harmonic voltage equation to the harmonic voltage equation set.

[0012] In one possible implementation, the feeder harmonic voltage equation is:

[0013] In the formula, The harmonic voltage difference between feeder nodes. The harmonic current vector of the target bus segment. The target bus section harmonic impedance, This refers to the sequence number of the last power feeder among multiple power feeders at the front end of the feeder to be processed. This refers to the sequence number of the load feeder located at the forefront among multiple power feeders at the rear of the feeder to be processed. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder To flow from the main power supply to the first The through current vector of the load feeder.

[0014] In one possible implementation, the cross-current vector equation is:

[0015] In the formula, For the first Harmonic current vector of a power supply feeder For the first Harmonic current vector of the load feeder This represents the total number of power feeders. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder.

[0016] In one possible implementation, determining the harmonic source based on the harmonic impedances of multiple bus segments and the multiple harmonic current datasets includes: Solve the harmonic voltage equations to obtain the harmonic impedance values ​​of the multiple bus segments and multiple through current vectors, wherein the through current vector is a harmonic current vector that originates from a power supply feeder and arrives at a load feeder or originates from the main power supply and arrives at a load feeder. For each feeder, multiple first bus segments and multiple first through current vectors are found according to the topology to construct a feeder harmonic parameter set, wherein the first through current vector is a harmonic current vector with the load feeder as the end point or the power feeder as the starting point, and the first bus segment is the bus segment through which the first through current vector flows. Based on the aforementioned topology, a harmonic contribution equation expressing the harmonic contribution degree is constructed; Substitute multiple feeder harmonic parameter sets into the harmonic contribution equation to obtain multiple harmonic contribution degrees, where each harmonic contribution degree corresponds to a feeder. The feeder with the largest harmonic contribution is taken as the feeder where the harmonic source is located.

[0017] In one possible implementation, if the feeder is a power supply feeder, the harmonic contribution equation is:

[0018] In the formula, For the first Harmonic contribution of a power feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each power feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows; If the feeder is a load feeder, the harmonic contribution equation is:

[0019] In the formula, For the first Harmonic contribution of a single load feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each load feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows.

[0020] In a second aspect, embodiments of the present invention provide a harmonic source locating device for implementing the harmonic source locating method as described in the first aspect or any possible implementation thereof, the harmonic source locating device comprising: The feeder current waveform acquisition module is used to acquire a current waveform dataset, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply. The harmonic current analysis module is used to perform harmonic current analysis on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, and construct a harmonic current dataset from the obtained multiple harmonic current vectors. The harmonic voltage equation construction module is used to construct a set of harmonic voltage equations that express the relationship between harmonic current, bus segment harmonic impedance and harmonic voltage difference between feeders, based on the topology consisting of the main power supply, multiple load feeders and multiple power supply feeders and the harmonic current dataset. as well as, The harmonic source location module is used to determine the harmonic source based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

[0021] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program executable on the processor, and the processor executes the computer program to implement the steps of the method as described in the first aspect or any possible implementation of the first aspect.

[0022] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as described in the first aspect or any possible implementation thereof.

[0023] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: This invention discloses a method for locating harmonic sources. The method first acquires a current waveform dataset, which includes multiple feeder current data queues, each corresponding to a power feeder, a load feeder, or the main power supply. Then, it performs harmonic current analysis on the multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, obtaining multiple harmonic current vectors to construct a harmonic current dataset. Next, based on the topology formed by the main power supply, multiple load feeders, and multiple power feeders, and the harmonic current dataset, it constructs a set of harmonic voltage equations expressing the relationship between harmonic current, bus segment harmonic impedance, and the harmonic voltage difference between feeders. Finally, it determines the harmonic source based on the multiple bus segment harmonic impedances and the multiple harmonic current datasets, wherein the bus segment harmonic impedances are determined based on the multiple harmonic current datasets and the harmonic voltage equations. This invention analyzes the direction of harmonic current and harmonic impedance in the power grid based on harmonic current and topology, and finally determines the feeder that contributes the most to harmonics. Its analysis method combines the characteristics of harmonic current and harmonic impedance, making the location of harmonic sources more accurate. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of the harmonic source localization method provided in the embodiments of the present invention; Figure 2 This is an application scenario diagram of the harmonic source localization method provided by the embodiments of the present invention; Figure 3 This is a schematic diagram of the harmonic voltage difference provided in the embodiments of the present invention; Figure 4 This is a functional block diagram of the harmonic source locating device provided in the embodiments of the present invention; Figure 5 This is a functional block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0026] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, so as to provide a thorough understanding of embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0028] The embodiments of the present invention will be described in detail below. This example is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0029] Figure 1 A flowchart of a harmonic source localization method provided for an embodiment of the present invention.

[0030] like Figure 1 The diagram illustrates the implementation flowchart of the harmonic source localization method provided by the embodiments of the present invention, which is described in detail below: In step 101, a current waveform dataset is obtained, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply.

[0031] In step 102, harmonic current analysis is performed on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, and multiple harmonic current vectors are obtained to construct a harmonic current dataset.

[0032] In some implementations, the step of performing harmonic current analysis on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, and constructing multiple harmonic current vectors into a harmonic current dataset, includes: For the multiple feeder current waveform data queues in the current waveform dataset, the following steps are performed respectively: Based on the first formula, the target harmonic, and the feeder current waveform data queue, the harmonic active current and harmonic reactive current are extracted, wherein the first formula is:

[0033] In the formula, Harmonic active current, This is harmonic reactive current. Pi The harmonic order of the target harmonic. The power frequency. The number of times the current data is sampled within the target harmonic period. The first in the feeder current waveform data queue One data point, This represents the total number of data items in the feeder current waveform data queue. The sampling rate of the current waveform data queue; The harmonic active current is used as the real part, and the harmonic reactive current is used as the imaginary part to construct the harmonic current vector.

[0034] For example, such as Figure 2 As shown in the figure, this figure illustrates an application scenario of an embodiment of the present invention. In the figure, the main power supply 201 is connected to multiple power feeders 204 and multiple load feeders 206 via a bus 202. The other end of the power feeder 204 is connected to the distributed power supply 203, meaning that the distributed power supply 203 generates electricity through the power feeder 204. The other end of the load feeder 206 is connected to the load, meaning that the load feeder 206 is responsible for transmitting electrical energy to each load end 205.

[0035] Busbar 202 is divided into busbar segments by two adjacent feeders. The rightmost number of the busbar segments shown in the diagram (which is also the total number of busbar segments) is... The maximum value of the serial number of power feeder 204 (which is also the total number of power feeders 204) is The maximum value required for load feeder 206 (which is also the total number of load feeders) is As can be seen from the scene shown in the image above... .

[0036] For ease of description, the front end and the back end are defined in this invention according to the direction of electrical energy transmission on the bus 202. That is, the end closer to the main power supply 201 is the front end, and the opposite end is the back end.

[0037] The current flows in the direction of the arrows shown in the diagram. On bus 202, the current flows from the main power source 201 side to the right. On load feeder 206, the current flows from bus 202 side to load end 205, and on power feeder 204, the current flows from distributed power source 203 end to bus 202.

[0038] Obtaining a current waveform dataset is fundamental for subsequent harmonic current analysis. This dataset comprises multiple independent feeder current data queues, each with a unique associated object, which can be a power supply feeder, a load feeder, or the main power source. Specifically, the current waveform data queue corresponding to a power supply feeder reflects the current variation characteristics of the power supply side feeder, the current waveform data queue corresponding to a load feeder reflects the current fluctuations of the power consumption side feeder, and the current waveform data queue corresponding to the main power source characterizes the current operating status of the entire power distribution system's main power supply end. All of these feeder current waveform data queues are time-series data sequences, continuously acquired by current sensors at corresponding locations at a preset sampling frequency, ensuring data continuity and accuracy, and providing reliable data support for subsequent accurate harmonic current analysis.

[0039] Based on the known harmonics of the power grid, i.e., the target harmonics, harmonic current analysis is performed on multiple feeder current waveform data queues contained in the current waveform dataset. Through this analysis, the core characteristic parameter of each feeder current waveform data queue under the target harmonics—the harmonic current vector—can be extracted. Subsequently, the multiple harmonic current vectors corresponding to all feeders are organized and combined according to preset rules to construct a harmonic current dataset for subsequent analysis (such as harmonic source tracing, harmonic mitigation effect evaluation, etc.). Among them, the target harmonics are specific harmonics (e.g., the 7th typical characteristic harmonic) preset according to the actual monitoring needs of the distribution system and the key points of harmonic mitigation. The core purpose of harmonic current analysis is to separate the fundamental component and non-target harmonic components from the current waveform and accurately extract the current characteristics corresponding to the target harmonics. The harmonic current vector is a quantitative representation of the target harmonic current characteristics, which contains key information such as the amplitude and phase of the current under the target harmonics. The constructed harmonic current dataset can realize centralized control and batch analysis of the target harmonic status of each feeder in the entire distribution system.

[0040] Based on the target harmonics, harmonic current analysis is performed on multiple feeder current waveform data queues in the current waveform dataset. The resulting multiple harmonic current vectors are then constructed into a harmonic current dataset. This can be achieved in the following way: The first step involves calculating and extracting the harmonic active current and harmonic reactive current of the feeder under the target harmonic based on the preset first formula, the pre-determined target harmonic parameters, and the currently processed feeder current waveform data queue. The first formula used to calculate the harmonic active current and harmonic reactive current is as follows:

[0041] The specific meanings of each parameter in the formula are as follows: The active harmonic current represents the harmonic current corresponding to the target harmonic, which reflects the component of the target harmonic current that does work externally. The harmonic reactive current corresponding to the target harmonic reflects the component in the target harmonic current that does not do external work but only generates energy exchange. Pi (usually 3.14159). The harmonic order of the target harmonic is determined by a preset target harmonic (e.g., when the target harmonic is the 7th harmonic). ); This refers to the power frequency; in some countries, the standard power frequency is 50Hz, corresponding to... rad / s; The number of times the current data is sampled within the target harmonic period is determined by the sampling rate and the target harmonic frequency, and is a key parameter to ensure the accuracy of harmonic current calculation. The current feeder current waveform data queue is the first one being processed. One sampled data; The index of the sampled data (value range from 0 to IN-1); This is the total number of current sampling data contained in the current waveform data queue of the feeder, which depends on the data acquisition duration and sampling frequency; The sampling rate is the number of samples taken per unit time for the current waveform data queue. The sampling rate setting must satisfy the Nyquist sampling theorem to ensure that the waveform characteristics of the target harmonics can be fully captured and to avoid frequency aliasing from affecting the analysis results.

[0042] The second step is to calculate the harmonic active current using the first formula mentioned above. As the real part of a complex vector, the harmonic reactive current As the imaginary part of a complex vector, combined with the rules for constructing complex vectors, the harmonic current vector corresponding to the target harmonic of the feeder is formed.

[0043] This harmonic current vector can fully characterize the amplitude (obtained by the square root of the sum of the squares of the real and imaginary parts) and phase (obtained by the arctangent of the imaginary and real parts) of the target harmonic current, realizing the accurate quantification of the target harmonic current characteristics and laying the foundation for the subsequent integration of the harmonic current vectors of all feeders into a harmonic current dataset.

[0044] In step 103, based on the topology consisting of the main power supply, multiple load feeders, and multiple power supply feeders, and the harmonic current dataset, a set of harmonic voltage equations is constructed to express the relationship between harmonic current, bus segment harmonic impedance, and harmonic voltage difference between feeders.

[0045] In some implementations, based on the topology consisting of the main power supply, multiple load feeders, and multiple power feeders, and the harmonic current dataset, a set of harmonic voltage equations expressing the relationship between harmonic current, bus segment harmonic impedance, and inter-feeder harmonic voltage difference is constructed, including: Construct multiple through current vectors, where each through current vector is a harmonic current vector originating from a power supply feeder and arriving at a load feeder or originating from the main power supply and arriving at a load feeder. Based on the relationship between the multiple through current vectors and harmonic current vectors, a through current vector equation is constructed, and the through current vector equation is added to the harmonic voltage equation set. From the plurality of load feeders and the plurality of power feeders, feeders are selected one by one as feeders to be processed, and the following steps are performed on each feeder to be processed: Based on the topology, multiple target current vectors are selected from the multiple current vectors, wherein the target current vectors pass through the target bus segment, and the feeder to be processed is connected to the rear end of the target bus segment; For the target bus segment, a target bus segment current vector is constructed based on the plurality of target through current vectors; Based on the harmonic voltage difference between feeder nodes, the harmonic impedance of the target bus segment, and the current vector of the target bus segment, a feeder harmonic voltage equation is constructed, wherein the harmonic voltage difference between feeder nodes is the voltage difference between the current feeder node and the previous feeder node. Add the harmonic voltage equation to the harmonic voltage equation set.

[0046] In some implementations, the feeder harmonic voltage equation is:

[0047] In the formula, The harmonic voltage difference between feeder nodes. The harmonic current vector of the target bus segment. The target bus section harmonic impedance, This refers to the sequence number of the last power feeder among multiple power feeders at the front end of the feeder to be processed. This refers to the sequence number of the load feeder located at the forefront among multiple power feeders at the rear of the feeder to be processed. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder To flow from the main power supply to the first The through current vector of the load feeder.

[0048] In some implementations, the through current vector equation is:

[0049] In the formula, For the first Harmonic current vector of a power supply feeder For the first Harmonic current vector of the load feeder This represents the total number of power feeders. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder.

[0050] For example, based on the power distribution system topology obtained in the aforementioned steps (i.e., the actual connection relationship between the main power supply, multiple load feeders and multiple power supply feeders), and combined with the completed harmonic current dataset, by sorting out the inherent electrical correlation between the three, a set of harmonic voltage equations can be constructed that can accurately express the quantitative relationship between the three core electrical parameters: harmonic current, bus section harmonic impedance and harmonic voltage difference between feeders.

[0051] The core purpose of this step is to transform the topological characteristics and harmonic current features of the power distribution system into a solvable mathematical model. By solving this set of equations, key parameters such as the harmonic impedance of the bus section and the harmonic voltage difference of the feeder can be further obtained.

[0052] The topology specifically refers to the connection method between the main power supply, power feeders, load feeders and bus segments. Typically, the main power supply is directly connected to the core bus segment, multiple power feeders are connected in parallel to the corresponding bus segments to achieve multi-path power supply, and multiple load feeders are led out from the bus segments to connect various electrical loads. As the core node for current distribution and voltage bearing, the harmonic impedance of the bus segment directly affects the harmonic voltage difference between feeders, while the flow characteristics of harmonic current are jointly determined by the topology and the load characteristics of each feeder. The relationship between the three can be systematically quantified through the harmonic voltage equation set.

[0053] Regarding the construction of harmonic voltage equations: The first step is to construct multiple through-current vectors. The core definition of a through-current vector is: a harmonic current vector originating from any power supply feeder and ultimately arriving at any load feeder, or a harmonic current vector originating from the main power supply and directly arriving at any load feeder. The essence of constructing through-current vectors is to decompose the actual flow paths of harmonic currents in the power distribution system. Since harmonic currents in the power distribution system mainly flow from the power supply end (main power supply, power supply feeder) to the power consumption end (load feeder), and there are multiple parallel flow paths between different power supply ends and power consumption ends, through-current vectors can accurately quantify the magnitude and phase of the harmonic current on each flow path, providing basic variables for the subsequent construction of the equation system. It should be noted that there is a clear relationship between the through-current vector and the harmonic current vector mentioned earlier: the harmonic current vector is a representation of the overall harmonic current of a certain feeder (power supply feeder, load feeder, or main power supply), while the through-current vector is a decomposition of the harmonic current vector on a specific flow path. The two can be derived from each other through quantitative relationships.

[0054] The second step involves constructing a through-current vector equation based on the inherent quantitative relationship between the multiple through-current vectors and the harmonic current vectors extracted earlier. This through-current vector equation is then added to the harmonic voltage equation set as one of the core equations. The core function of this equation is to establish the constraint relationship between the through-current vector and the feeder harmonic current vector, ensuring that the equation set reflects the electrical law that "the overall harmonic current of the feeder is equal to the sum of the through-currents of all its branches," thus avoiding problems such as unconstrained variables and unsolvable equation sets.

[0055] The third step involves sequentially selecting each of the multiple load feeders and multiple power feeders as the feeder to be processed, and constructing the corresponding feeder harmonic voltage equation: First, based on the topology of the power distribution system, the connection location of the feeder to be processed is determined—focusing on identifying the bus segment to which the feeder to be processed is connected (i.e., the target bus segment), and the connection relationship between the feeder to be processed and the target bus segment (the feeder to be processed is connected to the rear end of the target bus segment, meaning that the current of the feeder to be processed originates from the target bus segment). Then, from the multiple current vectors constructed in the first step, all current vectors passing through the target bus segment are selected and used as the target current vector. The core logic of this selection is that the harmonic current of the target bus segment is the superposition of all current vectors passing through the bus segment, and the harmonic current of the feeder to be processed originates from the target bus segment; therefore, the target current vector directly determines the harmonic state of the bus segment corresponding to the feeder to be processed.

[0056] Then, for the selected target bus segment, a target bus segment current vector is constructed based on the superposition pattern of multiple target current vectors. Since multiple target current vectors all pass through the target bus segment, their current directions on the target bus segment are consistent (both flowing from the front end to the rear end of the bus segment, or vice versa, depending on the topology). Therefore, the target bus segment current vector is equal to the vector sum of all target current vectors. This vector sum accurately represents the magnitude and phase of the total harmonic current of the target bus segment under the target harmonics, and is the core intermediate parameter for subsequent calculations of the bus segment harmonic impedance and the harmonic voltage difference between feeders.

[0057] Next, based on Ohm's law relationships between the harmonic voltage difference between feeder nodes, the harmonic impedance of the target bus segment, and the current vector of the target bus segment, a feeder harmonic voltage equation is constructed. The harmonic voltage difference between feeder nodes is explicitly defined as the harmonic voltage difference between the current feeder node (the connection node between the feeder to be processed and the target bus segment) and the previous feeder node (the connection node at the front end of the target bus segment). This difference is essentially the voltage drop generated in the target bus segment under the influence of harmonic current, and its magnitude is directly related to the harmonic impedance and current vector of the target bus segment.

[0058] Finally, the constructed feeder harmonic voltage equations are added to the harmonic voltage equation set. By performing the above steps on each feeder to be processed, multiple feeder harmonic voltage equations can be constructed. Combined with the through current vector equations from the second step, a complete harmonic voltage equation set is finally formed. This equation set covers all the key harmonic electrical relationships in the power distribution system and can be used to subsequently solve core parameters such as bus section harmonic impedance and inter-feeder harmonic voltage difference.

[0059] like Figure 3 As shown in the figure, this diagram illustrates the principle of the harmonic voltage difference between the feeder nodes corresponding to the feeder to be processed. The harmonic voltage difference between the feeder to be processed and the front-end feeder in the figure is shown. It is generated by the harmonic current flowing through the corresponding busbar segment and the impedance of the busbar segment. The current flowing through this busbar segment is the combined current of the harmonic currents that originate from the power supply at the front end of the busbar segment and terminate at the load end at the rear end of the busbar segment. Here, the last number in the power supply feeder at the front end of the busbar segment is... The first number in the load terminal at the rear end of the busbar section is .

[0060] The feeder harmonic voltage equation uses the following quantitative expression, which is derived based on Ohm's law and accurately quantifies the relationship between the harmonic voltage difference between feeder nodes, the harmonic current vector of the target bus segment, and the harmonic impedance of the target bus segment:

[0061] The specific meanings of each parameter in the formula are as follows: It represents the harmonic voltage difference between feeder nodes corresponding to the feeder to be processed. The unit is the same as the voltage unit (usually V). Its value is equal to the voltage drop generated by the target bus section under the action of harmonic current. Let be the harmonic current vector of the target bus segment, which is the vector sum of all target crossing current vectors, representing the total harmonic current of the target bus segment under the target harmonics, and its amplitude. This is the effective value of the total harmonic current; The target bus section harmonic impedance is the equivalent impedance of the target bus section at the target harmonic frequency. Its value is determined by parameters such as the resistance and inductance of the bus section and is a core parameter reflecting the harmonic loss and voltage drop characteristics of the bus section. This refers to the sequence number of the last power feeder among multiple power feeders at the front end of the feeder to be processed. The sequence number can be set sequentially from left to right or from the main power supply side to the load side according to the topology, in order to clarify the range of power feeders to be superimposed and calculated. The sequence number of the foremost load feeder among multiple load feeders at the rear end of the feeder to be processed is used to clarify the starting range of the load feeders for superposition calculation. This represents the total number of load feeders in the power distribution system, used to define the upper limit for the superposition calculation of load feeders; For from the first The power feeder flows to the first The magnitude and phase of the through current vector of the load feeder are derived from the harmonic current vectors of the two feeders, and are the basis for constructing the current vector of the bus segment. To flow from the main power supply to the first The through current vector of the load feeder.

[0062] The vector equation for the current flowing through is as follows:

[0063] The specific meanings of each parameter in the formula are as follows: For the first The harmonic current vector of the power feeder is exactly the same as the harmonic current vector of the power feeder extracted in step 102, representing the harmonic current vector of the power feeder. Total harmonic current of a power supply feeder under the target harmonic; For the first The harmonic current vector of the load feeder is exactly the same as the harmonic current vector of the load feeder extracted in step 102 above, representing the first... Total harmonic current of a load feeder under the target harmonic; This represents the total number of power supply feeders in the power distribution system, used to define the upper limit for the superposition calculation of power supply feeders; This represents the total number of load feeders in the power distribution system, consistent with the meaning of the parameters mentioned above. For from the first The power feeder flows to the first The through current vector of the load feeder is consistent with the previous definition.

[0064] The core logic of this equation is that the total harmonic current of a power supply feeder is equal to the sum of the current vectors flowing from that power supply feeder to all load feeders; the total harmonic current of a load feeder is equal to the sum of the current vectors flowing from all power supply feeders to that load feeder. This fully conforms to the conservation law of harmonic current in the power distribution system and provides key constraints for the harmonic voltage equation set.

[0065] In step 104, the harmonic source is determined based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

[0066] In some implementations, determining the harmonic source based on the harmonic impedances of multiple bus segments and the multiple harmonic current datasets includes: Solve the harmonic voltage equations to obtain the harmonic impedance values ​​of the multiple bus segments and multiple through current vectors, wherein the through current vector is a harmonic current vector that originates from a power supply feeder and arrives at a load feeder or originates from the main power supply and arrives at a load feeder. For each feeder, multiple first bus segments and multiple first through current vectors are found according to the topology to construct a feeder harmonic parameter set, wherein the first through current vector is a harmonic current vector with the load feeder as the end point or the power feeder as the starting point, and the first bus segment is the bus segment through which the first through current vector flows. Based on the aforementioned topology, a harmonic contribution equation expressing the harmonic contribution degree is constructed; Substitute multiple feeder harmonic parameter sets into the harmonic contribution equation to obtain multiple harmonic contribution degrees, where each harmonic contribution degree corresponds to a feeder. The feeder with the largest harmonic contribution is taken as the feeder where the harmonic source is located.

[0067] In some implementations, the harmonic contribution equation is:

[0068] In the formula, For the first Harmonic contribution of a power feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each power feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows; If the feeder is a load feeder, the harmonic contribution equation is:

[0069] In the formula, For the first Harmonic contribution of a single load feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each load feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows.

[0070] For example, based on the multiple bus segment harmonic impedances and multiple harmonic current datasets obtained from the previous steps, the specific location of the harmonic source in the power distribution system is finally determined by quantitatively analyzing the contribution of each feeder to the system harmonics.

[0071] This step is the core objective of the entire harmonic current analysis process. It is important to clarify that the harmonic impedance of the bus section is not a pre-known parameter. It needs to be obtained through mathematical solutions using multiple harmonic current datasets (containing harmonic current vectors for each feeder) constructed in the aforementioned steps, combined with the constructed harmonic voltage equations. The solution process must satisfy the electrical constraints of the power distribution system to ensure the accuracy and rationality of the bus section harmonic impedance value.

[0072] The process of determining the harmonic source based on multiple bus segment harmonic impedances and multiple harmonic current datasets is as follows: The first step is to solve the constructed harmonic voltage equations, and finally obtain two core parameters: multiple bus segment harmonic impedance values ​​and multiple through current vectors.

[0073] Among them, the harmonic impedance value of the bus section corresponds to the equivalent impedance of each bus section in the power distribution system under the target harmonic. Its value directly reflects the bus section's ability to impede harmonic current and its loss characteristics. It is the core parameter for quantifying harmonic propagation loss. The definition of the current vector is completely consistent with the definition in step 103 above, that is, the harmonic current vector that starts from any power supply feeder and arrives at any load feeder, or the harmonic current vector that starts from the main power supply and arrives at any load feeder.

[0074] It should be noted that solving the harmonic voltage equations requires considering the actual operating conditions of the power distribution system and employing appropriate mathematical methods (such as the least squares method, the Newton-Raphson method, etc.). Due to the large number of feeders and busbar segments in the power distribution system, the harmonic voltage equations are usually overdetermined. Using the least squares method can effectively reduce the impact of data measurement errors and sampling errors on the solution results, ensuring the accuracy of the harmonic impedance values ​​and through current vectors of the busbar segments, and providing reliable basic parameters for subsequent steps.

[0075] The second step is to systematically analyze and integrate the parameters of each feeder in the power distribution system (including all power feeders and all load feeders) to construct the corresponding feeder harmonic parameter set.

[0076] Specifically, firstly, based on the topology of the power distribution system, the connection relationship and current flow of the current feeder are clarified. Then, multiple first busbar segments and multiple first through current vectors related to the feeder are found. After integrating the two, a feeder-specific harmonic parameter set is formed, realizing centralized control of the harmonic parameters related to a single feeder, which facilitates subsequent targeted calculation of its harmonic contribution.

[0077] The definition of the first through current vector needs to be clearly distinguished in conjunction with the type of the current feeder: If the current feeder is a load feeder, then the first through current vector is all through current vectors that flow to the load feeder (i.e., all through current vectors that flow from the main power supply or power feeder to the load feeder). If the current feeder is a power feeder, then the first through current vector is all through current vectors that originate from the power feeder (i.e., all through current vectors that flow from the power feeder to each load feeder).

[0078] The first bus segment is all the bus segments through which the first through current vectors flow during their flow. Since the flow path of the first through current vector is determined by the topology, the bus segments through which it flows are all directly electrically related to the current feeder. The harmonic impedance of these bus segments will directly affect the harmonic loss of the current feeder's related through current, so they need to be included in the feeder harmonic parameter set.

[0079] The third step is to construct a harmonic contribution equation that can accurately express the harmonic contribution of each feeder, based on the topology of the power distribution system and the laws of harmonic propagation and active power loss.

[0080] The core meaning of harmonic contribution is: the harmonic voltage loss generated by a single feeder when it flows through the corresponding bus segment through its associated through current vector. The greater the loss, the greater the contribution of the feeder to the system harmonics, and the higher the probability that it becomes a harmonic source.

[0081] Therefore, the core of constructing the harmonic contribution equation is to quantify the voltage loss relationship between the "through current vector" and the "bus segment harmonic impedance", and to clarify the through current path and bus segment range corresponding to each feeder in combination with the topology, so as to ensure that the equation can truly reflect the harmonic contribution of a single feeder.

[0082] It should be noted that the harmonic contribution equation needs to be constructed separately according to the feeder type (power feeder, load feeder) because the current start and end points and the definition of the through current vector differ between the two.

[0083] The fourth step involves substituting the multiple feeder harmonic parameter sets constructed in the second step into the corresponding harmonic contribution equations constructed in the third step, calculating the harmonic contribution degree for each feeder. This results in multiple harmonic contribution degree data sets, with each harmonic contribution degree uniquely corresponding to a single feeder (a one-to-one correspondence). During the calculation, the feeder harmonic parameter sets for power feeders are substituted into the corresponding harmonic contribution equations, and the feeder harmonic parameter sets for load feeders are substituted into the corresponding harmonic contribution equations.

[0084] The fifth step is to sort and compare the calculated harmonic contributions, select the feeder with the largest harmonic contribution, and identify the feeder where the harmonic source is located.

[0085] The core logic of this step is that the feeder with the largest harmonic contribution will generate the largest harmonic voltage loss when the harmonic current flows through the relevant bus section, indicating that the feeder is the main source of system harmonics, i.e., the location of the harmonic source.

[0086] It should be noted that if the harmonic contribution of multiple feeders is relatively small (e.g., the difference is within the preset threshold range), these feeders can be determined to be harmonic sources (i.e., multiple harmonic sources coexist), and harmonic mitigation should be carried out on them separately. If the harmonic contribution of a certain feeder is much greater than that of other feeders (e.g., exceeding the preset threshold), then the feeder can be determined to be the main harmonic source, and it should be prioritized for mitigation to quickly reduce the harmonic content of the system.

[0087] The specific form of the harmonic contribution equation differs for different types of feeders (power feeders, load feeders), as follows: If the feeder to be calculated is a power supply feeder, the harmonic contribution equation is:

[0088] The specific meanings of each parameter in the formula are as follows: For the first The harmonic contribution of a power feeder is such that the larger the value, the greater the contribution of the power feeder to the system harmonics. For from the first The power feeder flows to the first The through current vector of the load feeder; This is the magnitude (RMS value) of the through current vector; For the first The total number of through currents corresponding to a power feeder, that is, the total number of through current vectors flowing from the power feeder to all load feeders, is equal to the total number of load feeders in the power distribution system (if the power feeder is not electrically connected to some load feeders, then it is the number of load feeders that are actually connected). For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first Harmonic impedance of each busbar segment; For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of a load feeder flows is determined by the flow path of that through current in the topology; the longer the path, the more bus segments it flows through. The larger the value, the better.

[0089] The core logic of this equation is: the first The total harmonic contribution of a power feeder is equal to the sum of harmonic voltage losses generated by all its through current vectors as they flow through each bus segment on their respective paths. The total loss is the harmonic contribution of the feeder.

[0090] If the feeder to be calculated is a load feeder, the harmonic contribution equation is:

[0091] The specific meanings of each parameter in the formula are as follows: For the first The harmonic contribution of a load feeder is such that the larger the value, the greater the contribution of the load feeder to the system harmonics. For from the first The power feeder flows to the first The through current vector of the load feeder; For the first The total number of through currents corresponding to a load feeder, that is, the total number of all through current vectors flowing from the power supply feeder (or main power supply) to the load feeder, is equal to the total number of power supply feeders in the power distribution system (if the load feeder is not electrically connected to some power supply feeders, then it is the number of power supply feeders that are actually connected). For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first Harmonic impedance of each busbar segment; For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of a load feeder flows is determined by the flow path of that through current in the topology, and is related to the contribution equation of the power supply feeder. The logic is consistent.

[0092] The core logic of this equation is: the first The total harmonic contribution of a load feeder is equal to the sum of harmonic voltage losses generated by all through current vectors flowing to that load feeder as they pass through each bus segment on their respective paths. The sum of these losses is the harmonic contribution of that load feeder.

[0093] The implementation method of the harmonic source localization method of this invention first acquires a current waveform dataset, which includes multiple feeder current data queues, each corresponding to a power feeder, a load feeder, or the main power source. Then, based on the target harmonic, harmonic current analysis is performed on the multiple feeder current waveform data queues in the current waveform dataset, resulting in multiple harmonic current vectors that form a harmonic current dataset. Next, based on the topology formed by the main power source, multiple load feeders, and multiple power feeders, and the harmonic current dataset, a set of harmonic voltage equations expressing the relationship between harmonic current, bus segment harmonic impedance, and the harmonic voltage difference between feeders is constructed. Finally, the harmonic source is determined based on the multiple bus segment harmonic impedances and the multiple harmonic current datasets, where the bus segment harmonic impedance is determined based on the multiple harmonic current datasets and the harmonic voltage equations. This invention, based on harmonic current and topology, analyzes the direction of harmonic current and harmonic impedance in the power grid, ultimately identifying the feeder with the largest harmonic contribution. Its analysis method combines the characteristics of harmonic current and harmonic impedance, resulting in more accurate harmonic source localization.

[0094] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0095] The following are embodiments of the apparatus of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0096] Figure 4 This is a functional block diagram of the harmonic source locating device provided in the embodiments of the present invention, with reference to... Figure 4 The harmonic source location device includes: a feeder current waveform acquisition module 401, a harmonic current analysis module 402, a harmonic voltage equation construction module 403, and a harmonic source location module 404, wherein: The feeder current waveform acquisition module 401 is used to acquire a current waveform dataset, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply. The harmonic current analysis module 402 is used to perform harmonic current analysis on multiple feeder current waveform data queues in the current waveform dataset according to the target harmonic, and construct a harmonic current dataset by obtaining multiple harmonic current vectors. The harmonic voltage equation construction module 403 is used to construct a set of harmonic voltage equations that express the relationship between harmonic current, bus segment harmonic impedance and harmonic voltage difference between feeders, based on the topology consisting of the main power supply, multiple load feeders and multiple power supply feeders and the harmonic current dataset. as well as, The harmonic source location module 404 is used to determine the harmonic source based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

[0097] Figure 5 This is a functional block diagram of the electronic device provided in an embodiment of the present invention. For example... Figure 5 As shown, the electronic device 5 of this embodiment includes a processor 500 and a memory 501, wherein the memory 501 stores a computer program 502 that can run on the processor 500. When the processor 500 executes the computer program 502, it implements the steps of the various harmonic source localization methods and embodiments described above, for example... Figure 1 Steps 101 to 104 are shown.

[0098] For example, the computer program 502 may be divided into one or more modules / units, which are stored in the memory 501 and executed by the processor 500 to complete the present invention.

[0099] The electronic device 5 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device 5 may include, but is not limited to, a processor 500 and a memory 501. Those skilled in the art will understand that... Figure 5 This is merely an example of electronic device 5 and does not constitute a limitation on electronic device 5. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 5 may also include input / output devices, network access devices, buses, etc.

[0100] The processor 500 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0101] The memory 501 can be an internal storage unit of the electronic device 5, such as a hard disk or memory. The memory 501 can also be an external storage device of the electronic device 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory 501 can include both internal and external storage units of the electronic device 5. The memory 501 is used to store the computer program 502 and other programs and data required by the electronic device 5. The memory 501 can also be used to temporarily store data that has been output or will be output.

[0102] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the aforementioned method embodiments, and will not be repeated here.

[0103] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0104] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0105] In the embodiments provided by this invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0106] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0107] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0108] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-described embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various methods and apparatus embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0109] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for locating harmonic sources, characterized in that, include: Acquire a current waveform dataset, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply. Harmonic current analysis is performed on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonics, and multiple harmonic current vectors are obtained to construct a harmonic current dataset. Based on the topology consisting of the main power supply, multiple load feeders, and multiple power supply feeders, and the harmonic current dataset, a set of harmonic voltage equations is constructed to express the relationship between harmonic current, bus segment harmonic impedance, and harmonic voltage difference between feeders. The harmonic source is determined based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

2. The harmonic source localization method according to claim 1, characterized in that, The step involves performing harmonic current analysis on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, obtaining multiple harmonic current vectors to construct a harmonic current dataset, including: For the multiple feeder current waveform data queues in the current waveform dataset, the following steps are performed respectively: Based on the first formula, the target harmonic, and the feeder current waveform data queue, the harmonic active current and harmonic reactive current are extracted, wherein the first formula is: In the formula, Harmonic active current, This is harmonic reactive current. Pi The harmonic order of the target harmonic. The power frequency. The number of times the current data is sampled within the target harmonic period. The first in the feeder current waveform data queue One data point, This represents the total number of data items in the feeder current waveform data queue. The sampling rate of the current waveform data queue; The harmonic active current is used as the real part, and the harmonic reactive current is used as the imaginary part to construct the harmonic current vector.

3. The harmonic source localization method according to claim 1, characterized in that, Based on the topology consisting of the main power supply, multiple load feeders, and multiple power feeders, and the aforementioned harmonic current dataset, a set of harmonic voltage equations expressing the relationship between harmonic current, bus segment harmonic impedance, and inter-feeder harmonic voltage difference is constructed, including: Construct multiple through current vectors, where each through current vector is a harmonic current vector originating from a power supply feeder and arriving at a load feeder or originating from the main power supply and arriving at a load feeder. Based on the relationship between the multiple through current vectors and harmonic current vectors, a through current vector equation is constructed, and the through current vector equation is added to the harmonic voltage equation set. From the plurality of load feeders and the plurality of power feeders, feeders are selected one by one as feeders to be processed, and the following steps are performed on each feeder to be processed: Based on the topology, multiple target current vectors are selected from the multiple current vectors, wherein the target current vectors pass through the target bus segment, and the feeder to be processed is connected to the rear end of the target bus segment; For the target bus segment, a target bus segment current vector is constructed based on the plurality of target through current vectors; Based on the harmonic voltage difference between feeder nodes, the harmonic impedance of the target bus segment, and the current vector of the target bus segment, a feeder harmonic voltage equation is constructed, wherein the harmonic voltage difference between feeder nodes is the voltage difference between the current feeder node and the previous feeder node. Add the harmonic voltage equation to the harmonic voltage equation set.

4. The harmonic source localization method according to claim 3, characterized in that, The equation for the feeder harmonic voltage is: In the formula, The harmonic voltage difference between feeder nodes. The harmonic current vector of the target bus segment. The target busbar segment harmonic impedance, This refers to the sequence number of the last power feeder among multiple power feeders at the front end of the feeder to be processed. This refers to the sequence number of the load feeder located at the forefront among multiple power feeders at the rear of the feeder to be processed. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder For the flow from the main power supply to the first The through current vector of the load feeder.

5. The harmonic source localization method according to claim 3, characterized in that, The vector equation for the through current is: In the formula, For the first Harmonic current vector of a power feeder. For the first Harmonic current vector of the load feeder This represents the total number of power feeders. This represents the total number of load feeders. For from the first The power feeder flows to the first The through current vector of the load feeder.

6. The harmonic source localization method according to any one of claims 1-5, characterized in that, The step of determining the harmonic source based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets includes: Solve the harmonic voltage equations to obtain the harmonic impedance values ​​of the multiple bus segments and multiple through current vectors, wherein the through current vector is a harmonic current vector that originates from a power supply feeder and arrives at a load feeder or originates from the main power supply and arrives at a load feeder. For each feeder, multiple first bus segments and multiple first through current vectors are found according to the topology to construct a feeder harmonic parameter set, wherein the first through current vector is a harmonic current vector with the load feeder as the end point or the power feeder as the starting point, and the first bus segment is the bus segment through which the first through current vector flows. Based on the aforementioned topology, a harmonic contribution equation expressing the harmonic contribution degree is constructed; Substitute multiple feeder harmonic parameter sets into the harmonic contribution equation to obtain multiple harmonic contribution degrees, where each harmonic contribution degree corresponds to a feeder. The feeder with the largest harmonic contribution is taken as the feeder where the harmonic source is located.

7. The harmonic source localization method according to claim 6, characterized in that, If the feeder is a power supply feeder, the harmonic contribution equation is: In the formula, For the first Harmonic contribution of a power feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each power feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows; If the feeder is a load feeder, the harmonic contribution equation is: In the formula, For the first Harmonic contribution of a single load feeder For from the first The power feeder flows to the first The through current vector of the load feeder For the first The total number of through currents corresponding to each load feeder. For from the first The power feeder flows to the first The through current vector of the load feeder flows through the first The impedance of each busbar segment For from the first The power feeder flows to the first The total number of bus segments through which the through current vector of the load feeder flows.

8. A harmonic source locating device, characterized in that, For implementing the harmonic source localization method as described in any one of claims 1-7, the harmonic source localization device comprises: The feeder current waveform acquisition module is used to acquire a current waveform dataset, wherein the current waveform dataset includes multiple feeder current data queues, and each feeder current waveform data queue corresponds to a power feeder, a load feeder, or a main power supply. The harmonic current analysis module is used to perform harmonic current analysis on multiple feeder current waveform data queues in the current waveform dataset based on the target harmonic, and construct a harmonic current dataset from the obtained multiple harmonic current vectors. The harmonic voltage equation construction module is used to construct a set of harmonic voltage equations that express the relationship between harmonic current, bus segment harmonic impedance and harmonic voltage difference between feeders, based on the topology consisting of the main power supply, multiple load feeders and multiple power supply feeders and the harmonic current dataset. as well as, The harmonic source location module is used to determine the harmonic source based on the harmonic impedance of multiple bus segments and the multiple harmonic current datasets, wherein the harmonic impedance of the bus segments is determined based on the multiple harmonic current datasets and the harmonic voltage equations.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 7 above.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7 above.

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