Power distribution network harmonic source positioning method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of power distribution network harmonic treatment, in particular to a power distribution network harmonic source positioning method and device, electronic equipment and a storage medium, and the method comprises the steps: firstly obtaining a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes; then waveform distortion analysis is carried out on the first voltage waveform data queue and the second voltage waveform data queue respectively, and a first voltage distortion rate and a second voltage distortion rate are obtained; according to the first voltage distortion rate and the second voltage distortion rate, whether a harmonic source is connected to the power distribution network or not is determined; and finally, when a harmonic source is accessed, extracting a plurality of node current pairs, and determining an area where the harmonic source is located according to the plurality of node current pairs. According to the embodiment of the invention, harmonic source positioning can be completed by using less monitoring equipment for harmonic source positioning, and equipment resources are saved.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution network harmonic control, and in particular to a method, device, electronic equipment and storage medium for locating a harmonic source in a power distribution network. Background Art

[0002] In order to solve the problems of global climate deterioration and the gradual depletion of fossil energy, the world is building a power grid system with new energy as the core. However, due to the "high power electronics" problem of new energy technology, the power grid, especially the distribution network, has serious harmonic problems. On the other hand, with the continuous advancement of control technology, more and more equipment supported by power electronics technology, such as variable frequency air conditioners, fluorescent lamps, etc., have made the harmonic problem of the distribution network increasingly serious.

[0003] At present, the requirement for harmonic problems is "whoever pollutes, whoever controls", and determining the "whoever pollutes" is the harmonic source tracing problem. Due to the coupling between the elements of the power grid, harmonics are transmitted to each other, making harmonic source tracing difficult. Although academia and industry have conducted a lot of harmonic source tracing research in recent years and accumulated many methods and technologies, these methods are more oriented to the main grid and require a large number of monitoring equipment, network topology parameters and other preconditions.

[0004] As we all know, due to the massive number of nodes in the distribution network, most of the current harmonic positioning uses a large number of signal acquisition devices and analysis equipment, which requires a large investment in hardware and construction. Using fewer devices to achieve harmonic positioning can significantly reduce the investment in construction and equipment resources.

[0005] Based on this, it is necessary to develop and design a method for locating harmonic sources in distribution networks. Summary of the invention

[0006] The embodiments of the present invention provide a method, device, electronic device and storage medium for locating harmonic sources in a distribution network, which are used to solve the problem that the prior art requires more equipment to complete the positioning of harmonics.

[0007] In a first aspect, an embodiment of the present invention provides a method for locating harmonic sources in a distribution network, comprising:

[0008] Acquire a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes;

[0009] Performing waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate;

[0010] Determining whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate;

[0011] When a harmonic source is connected, multiple node current pairs are extracted, and the area where the harmonic source is located is determined based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

[0012] In a possible implementation, performing waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate includes:

[0013] Acquire a fundamental frequency, wherein the fundamental frequency is a frequency of a main power supply output voltage;

[0014] The following steps are performed for the first voltage waveform data queue and the second voltage waveform data queue respectively:

[0015] Extracting the fundamental wave amplitude and the fundamental wave phase from the voltage waveform data queue according to the fundamental wave frequency, and performing difference calculation according to the fundamental wave amplitude, the fundamental wave phase and the voltage waveform data queue to generate a harmonic data queue;

[0016] generating a total harmonic amplitude according to the harmonic data queue;

[0017] The ratio of the total harmonic amplitude to the fundamental amplitude is taken as the voltage distortion rate.

[0018] In a possible implementation, extracting the fundamental wave amplitude and the fundamental wave phase from the voltage waveform data queue according to the fundamental wave frequency, and performing a difference operation according to the fundamental wave amplitude, the fundamental wave phase and the voltage waveform data queue to generate a harmonic data queue includes:

[0019] Generate a harmonic data queue according to a first formula, wherein the first formula is:

[0020]

[0021] Wherein, UA is the cosine component of the fundamental amplitude, QD(Wn) is the Wnth data in the voltage waveform data queue, WnMax is the total number of data in the voltage waveform data queue, cos() is the cosine function, sin() is the sine function, ω0 is the fundamental frequency, TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, UB is the sine component of the fundamental amplitude, U0 is the fundamental amplitude, α is the fundamental phase, arccos() is the inverse cosine function, HQD(Wn) is the Wnth data in the harmonic data queue, and π is pi.

[0022] In a possible implementation manner, generating the total harmonic amplitude according to the harmonic data queue includes:

[0023] The total harmonic amplitude is generated according to a second formula, wherein the second formula is:

[0024]

[0025] Where TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, WnMax is the total number of data in the voltage waveform data queue, HQD(Wn) is the Wnth data in the harmonic data queue, and U N is the total harmonic amplitude.

[0026] In a possible implementation manner, determining whether a harmonic source is connected to a distribution network according to the first voltage distortion rate and the second voltage distortion rate includes:

[0027] The harmonic distortion change rate is determined according to a third formula, the first voltage distortion rate, and the second voltage distortion rate, wherein the third formula is:

[0028]

[0029] Where ξ is the harmonic distortion change rate, U thd,t is the second voltage distortion rate, U thd,t-1 is the first voltage distortion rate;

[0030] If the harmonic distortion change rate is greater than the change rate threshold, it is determined that a harmonic source is connected to the distribution network.

[0031] In a possible implementation manner, determining the region where the harmonic source is located according to the multiple node current pairs includes:

[0032] Obtain the time when the harmonic source is connected to the distribution network;

[0033] Extracting node currents of the plurality of nodes before and after the harmonic source is connected to the distribution network, and constructing the plurality of node currents into a plurality of node current pairs according to correspondence with the nodes;

[0034] Determine a plurality of current variation amounts according to the plurality of current pairs, wherein each current variation amount corresponds to a node;

[0035] According to the line distance between the node and the main power supply, the multiple current changes are constructed into a change queue;

[0036] Sequentially taking out current variation from the variation queue as variation to be analyzed;

[0037] If the variation to be analyzed is the first current variation in the variation queue and the ratio of the variation to be analyzed to each second variation is greater than the first ratio, the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the second variation is the current variation after the variation to be analyzed in the variation queue;

[0038] If the variation to be analyzed is the current variation after the first current variation in the variation queue, the deviation between the variation to be analyzed and the first variation is less than the current deviation threshold, and the ratio between the variation to be analyzed and each second variation is greater than the first ratio, then the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the first variation is the current variation in the variation queue that is one position before the variation to be analyzed;

[0039] Otherwise, if the traversal of the variation queue is not completed, the process jumps to the step of sequentially taking out the current variation from the variation queue as the variation to be analyzed.

[0040] In a possible implementation, determining a plurality of current variation amounts according to the plurality of current pairs includes:

[0041] For each current pair, the current variation is determined according to the fourth formula, wherein the fourth formula is:

[0042] ΔI m =I post,m -I pre,m

[0043] In the formula, ΔI m is the current change of the mth node, I post,m is the current of the mth node before the harmonic source is connected to the distribution network, I pre,m is the current of the mth node before the harmonic source is connected to the distribution network.

[0044] In a second aspect, an embodiment of the present invention provides a distribution network harmonic source locating device, which is used to implement the distribution network harmonic source locating method described in the first aspect or any possible implementation of the first aspect, and the distribution network harmonic source locating device includes:

[0045] A data acquisition module, used for acquiring a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes;

[0046] A voltage distortion analysis module, used to perform waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively, to obtain a first voltage distortion rate and a second voltage distortion rate;

[0047] A harmonic source access determination module, used to determine whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate;

[0048] as well as,

[0049] The harmonic source positioning module is used to extract multiple node current pairs when a harmonic source is connected, and determine the area where the harmonic source is located based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

[0050] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the steps of the method described in the first aspect or any possible implementation method of the first aspect.

[0051] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0052] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0053] The embodiment of the present invention discloses a method for locating harmonic sources in a distribution network, which first obtains a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes; then respectively performs waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue to obtain a first voltage distortion rate and a second voltage distortion rate; then determines whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate; finally, when a harmonic source is connected, extracts multiple node current pairs, and determines the area where the harmonic source is located according to the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes node currents before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes. The embodiment of the present invention determines whether a harmonic source is connected based on the distortion of the voltage waveform, and when a harmonic source is connected, extracts the node current according to the time when the harmonic source is connected, and locates the harmonic source through the current change rate. The embodiment of the present invention can complete the harmonic source positioning with less monitoring equipment for harmonic source positioning, saving equipment resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] Figure 1 is a flow chart of a method for locating harmonic sources in a distribution network provided by an embodiment of the present invention;

[0056] Figure 2 is a typical distribution network schematic diagram provided by an embodiment of the present invention;

[0057] Figure 3 is a schematic diagram of a distribution network equipped with a power quality device provided in an embodiment of the present invention;

[0058] Figure 4 It is a schematic diagram of the distribution network area division provided by an embodiment of the present invention;

[0059] Figure 5 It is a functional block diagram of a harmonic source locating device for a distribution network provided by an embodiment of the present invention;

[0060] Figure 6 It is a functional block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and methods are omitted so as not to obscure the description of the present invention with unnecessary details.

[0062] In order to make the purpose, technical solutions and advantages of the present invention more clear, a specific implementation method will be described below in conjunction with the accompanying drawings.

[0063] The following is a detailed description of an embodiment of the present invention. This example is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0064] Figure 1 A flow chart of a method for locating harmonic sources in a distribution network provided in an embodiment of the present invention.

[0065] like Figure 1As shown, it shows a flow chart of the implementation of the method for locating harmonic sources in a distribution network provided by an embodiment of the present invention, which is described in detail as follows:

[0066] In step 101, a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes are obtained.

[0067] Exemplarily, the present invention proposes a harmonic source tracing method for distribution networks that relies on only 3-4 power quality monitoring devices. The method requires low investment and is easy to implement and promote.

[0068] The implementation mode of the present invention firstly needs to configure a certain amount of power quality monitoring equipment, through which the power quality information of the monitored object can be obtained.

[0069] like Figure 2 As shown, the distribution network usually presents a radial power supply mode, and there are many distribution network nodes. Due to limited investment capacity, only some nodes are currently equipped with power quality monitoring equipment.

[0070] The present invention does not require a large number of power quality devices, but at least 3-4 devices (set as M, numbered 1, 2...M from left to right) are needed to divide the power distribution into multiple sub-areas (the first node in the network must be configured), and the power quality monitoring devices are configured approximately evenly along the radial network main line. Figure 3 For example, the starting point and the subsequent two middle nodes in the figure are configured with power quality equipment, and the black nodes in the figure represent nodes configured with power quality monitoring equipment.

[0071] Subsequently, the distribution network is divided into multiple areas based on the power quality equipment. Specifically, along the power supply direction, two adjacent power quality devices are directly divided into one area. Figure 4 For example, the power grid is divided into three areas through three power quality monitoring devices.

[0072] The implementation mode of the present invention obtains two waveform data queues from the source of the distribution network. The two waveform data queues are adjacent to each other at the time node. Through the distortion analysis of the two waveform data queues, it can be analyzed whether there is a harmonic source connected to the distribution network. The specific method is discussed in detail in the following steps.

[0073] In step 102, waveform distortion analysis is performed on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate.

[0074] In some implementations, performing waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue to obtain a first voltage distortion rate and a second voltage distortion rate includes:

[0075] Acquire a fundamental frequency, wherein the fundamental frequency is a frequency of a main power supply output voltage;

[0076] The following steps are performed for the first voltage waveform data queue and the second voltage waveform data queue respectively:

[0077] Extracting the fundamental wave amplitude and the fundamental wave phase from the voltage waveform data queue according to the fundamental wave frequency, and performing difference calculation according to the fundamental wave amplitude, the fundamental wave phase and the voltage waveform data queue to generate a harmonic data queue;

[0078] generating a total harmonic amplitude according to the harmonic data queue;

[0079] The ratio of the total harmonic amplitude to the fundamental amplitude is taken as the voltage distortion rate.

[0080] In some implementations, extracting a fundamental wave amplitude and a fundamental wave phase from a voltage waveform data queue according to the fundamental wave frequency, and performing a difference operation according to the fundamental wave amplitude, the fundamental wave phase, and the voltage waveform data queue to generate a harmonic data queue includes:

[0081] Generate a harmonic data queue according to a first formula, wherein the first formula is:

[0082]

[0083] Wherein, UA is the cosine component of the fundamental amplitude, QD(Wn) is the Wnth data in the voltage waveform data queue, WnMax is the total number of data in the voltage waveform data queue, cos() is the cosine function, sin() is the sine function, ω0 is the fundamental frequency, TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, UB is the sine component of the fundamental amplitude, U0 is the fundamental amplitude, α is the fundamental phase, arccos() is the inverse cosine function, HQD(Wn) is the Wnth data in the harmonic data queue, and π is pi.

[0084] In some implementations, generating a total harmonic amplitude according to the harmonic data queue includes:

[0085] The total harmonic amplitude is generated according to a second formula, wherein the second formula is:

[0086]

[0087] Where TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, WnMax is the total number of data in the voltage waveform data queue, HQD(Wn) is the Wnth data in the harmonic data queue, and U N is the total harmonic amplitude.

[0088] Exemplarily, in terms of extracting the voltage waveform distortion rate, the embodiment of the present invention first obtains the fundamental frequency, then extracts the fundamental amplitude and fundamental phase for each voltage waveform data queue, and then performs a difference operation based on the fundamental amplitude, fundamental phase and voltage waveform data queue to generate a harmonic data queue. Specifically, the first formula is applied:

[0089]

[0090] Wherein, UA is the cosine component of the fundamental amplitude, QD(Wn) is the Wnth data in the voltage waveform data queue, WnMax is the total number of data in the voltage waveform data queue, cos() is the cosine function, sin() is the sine function, ω0 is the fundamental frequency, TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, UB is the sine component of the fundamental amplitude, U0 is the fundamental amplitude, α is the fundamental phase, arccos() is the inverse cosine function, HQD(Wn) is the Wnth data in the harmonic data queue, and π is pi.

[0091] Then, the total harmonic amplitude is generated according to the second formula, wherein the second formula is:

[0092]

[0093] Where TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, WnMax is the total number of data in the voltage waveform data queue, HQD(Wn) is the Wnth data in the harmonic data queue, and U N is the total harmonic amplitude.

[0094] The ratio of the total harmonic amplitude to the fundamental amplitude is taken as the voltage distortion rate.

[0095] In this way, the first voltage distortion rate and the second voltage distortion rate are obtained.

[0096] In step 103, it is determined whether a harmonic source is connected to the power distribution network according to the first voltage distortion rate and the second voltage distortion rate.

[0097] In some implementations, determining whether a harmonic source is connected to a distribution network according to the first voltage distortion rate and the second voltage distortion rate includes:

[0098] The harmonic distortion change rate is determined according to a third formula, the first voltage distortion rate, and the second voltage distortion rate, wherein the third formula is:

[0099]

[0100] Where ξ is the harmonic distortion change rate, Uthd，t is the second voltage distortion rate, U thd，t-1 is the first voltage distortion rate;

[0101] If the harmonic distortion change rate is greater than the change rate threshold, it is determined that a harmonic source is connected to the distribution network.

[0102] Exemplarily, the change in the harmonic voltage content rate of the first node is used to determine whether a harmonic source is connected. In other words, when a harmonic source uses electricity, the harmonic voltage content rate will change significantly.

[0103] The harmonic distortion change rate is captured and calculated periodically by the third formula, which is:

[0104]

[0105] Where ξ is the harmonic distortion change rate, U thd，t is the second voltage distortion rate, U thd，t-1 is the first voltage distortion rate; when ξ is greater than a certain threshold (usually 0.2, which can also be reasonably adjusted according to the load characteristics), it is determined that a harmonic source is connected.

[0106] In step 104, when a harmonic source is connected, multiple node current pairs are extracted, and the area where the harmonic source is located is determined based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

[0107] In some implementations, determining the region where the harmonic source is located according to the plurality of node current pairs includes:

[0108] Obtain the time when the harmonic source is connected to the distribution network;

[0109] Extracting node currents of the plurality of nodes before and after the harmonic source is connected to the distribution network, and constructing the plurality of node currents into a plurality of node current pairs according to correspondence with the nodes;

[0110] Determine a plurality of current variation amounts according to the plurality of current pairs, wherein each current variation amount corresponds to a node;

[0111] According to the line distance between the node and the main power supply, the multiple current changes are constructed into a change queue;

[0112] Sequentially taking out current variation from the variation queue as variation to be analyzed;

[0113] If the variation to be analyzed is the first current variation in the variation queue and the ratio of the variation to be analyzed to each second variation is greater than the first ratio, the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the second variation is the current variation after the variation to be analyzed in the variation queue;

[0114] If the variation to be analyzed is the current variation after the first current variation in the variation queue, the deviation between the variation to be analyzed and the first variation is less than the current deviation threshold, and the ratio between the variation to be analyzed and each second variation is greater than the first ratio, then the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the first variation is the current variation in the variation queue that is one position before the variation to be analyzed;

[0115] Otherwise, if the traversal of the variation queue is not completed, the process jumps to the step of sequentially taking out the current variation from the variation queue as the variation to be analyzed.

[0116] In some implementations, determining a plurality of current variation amounts according to the plurality of current pairs comprises:

[0117] For each current pair, the current variation is determined according to the fourth formula, wherein the fourth formula is:

[0118] ΔI m =I post，m -I pre，m

[0119] In the formula, ΔI m is the current change of the mth node, I post，m is the current of the mth node before the harmonic source is connected to the distribution network, I pre，m is the current of the mth node before the harmonic source is connected to the distribution network.

[0120] For example, the characteristic changes before and after the harmonic source is connected are finally calculated. After the harmonic source is connected, the current and other factors will change. The current collected by each power quality monitoring device m before and after the harmonic source is connected is calculated by the following formula:

[0121] ΔI m =I post，m -I pre，m

[0122] In the formula, ΔI m is the current change of the mth node, I post，m is the current of the mth node before the harmonic source is connected to the distribution network, I pre，m is the current of the mth node before the harmonic source is connected to the distribution network.

[0123] by Figure 4 Take the example of the harmonic source area as an example, according to the following principles:

[0124] If ΔI1>>ΔI m , then the harmonic source is considered to be in region 1, because the harmonic change in the region to which the harmonic source belongs is the largest. Usually, the standard for judging that it is far greater than (>>) is that ΔI1 is ΔI m More than 3 times;

[0125] If ΔI1≈ΔI m , ΔI2>>ΔI m (here m does not include node 1), the harmonic source is considered to be in area 2.

[0126] If Δi1≈ΔI2≈ΔI3, ΔI3>>ΔI m (here m does not include nodes 1 and 2), it is considered that the harmonic source is in area 3, and so on, the area where the harmonic source is located can be determined.

[0127] The embodiment of the method for locating harmonic sources in a distribution network of the present invention first obtains a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes; then respectively performs waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue to obtain a first voltage distortion rate and a second voltage distortion rate; then determines whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate; finally, when a harmonic source is connected, extracts multiple node current pairs, and determines the area where the harmonic source is located according to the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes. The embodiment of the present invention determines whether a harmonic source is connected based on the distortion of the voltage waveform, and when a harmonic source is connected, extracts the node current according to the time when the harmonic source is connected, and locates the harmonic source through the current change rate. The embodiment of the present invention can complete the harmonic source positioning with less monitoring equipment for harmonic source positioning, saving equipment resources.

[0128] It should be understood that the size of the serial numbers of the steps in the above implementation does not mean 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 implementation method of the present invention.

[0129] The following is an implementation of the device of the present invention. For details not described in detail, reference may be made to the corresponding method implementation described above.

[0130] Figure 5 is a functional block diagram of a harmonic source locating device for a distribution network provided by an embodiment of the present invention, referring to Figure 5 The distribution network harmonic source positioning device includes: a data acquisition module 501, a voltage distortion analysis module 502, a harmonic source access determination module 503 and a harmonic source positioning module 504, wherein:

[0131] The data acquisition module 501 is used to acquire a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes;

[0132] A voltage distortion analysis module 502 is used to perform waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate;

[0133] A harmonic source access determination module 503, configured to determine whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate;

[0134] The harmonic source positioning module 504 is used to extract multiple node current pairs when a harmonic source is connected, and determine the area where the harmonic source is located based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

[0135] Figure 6 is a functional block diagram of an electronic device provided by an embodiment of the present invention. Figure 6 As shown, the electronic device 6 of this embodiment includes: a processor 600 and a memory 601, wherein the memory 601 stores a computer program 602 that can be run on the processor 600. When the processor 600 executes the computer program 602, the steps in the above-mentioned distribution network harmonic source location method and implementation method are implemented, for example Figure 1 Steps 101 to 104 are shown.

[0136] Exemplarily, the computer program 602 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 601 and executed by the processor 600 to implement the present invention.

[0137] The electronic device 6 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device 6 may include, but is not limited to, a processor 600 and a memory 601. Those skilled in the art will appreciate that Figure 6 It is only an example of the electronic device 6 and does not constitute a limitation of the electronic device 6. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 6 may also include input and output devices, network access devices, buses, etc.

[0138] The processor 600 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) 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, etc.

[0139] The memory 601 may be an internal storage unit of the electronic device 6, such as a hard disk or memory of the electronic device 6. The memory 601 may also be an external storage device of the electronic device 6, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 6. Further, the memory 601 may also include both an internal storage unit and an external storage device of the electronic device 6. The memory 601 is used to store the computer program 602 and other programs and data required by the electronic device 6. The memory 601 may also be used to temporarily store data that has been output or is to be output.

[0140] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned function allocation can be completed by 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 implementation method can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method implementation method, which will not be repeated here.

[0141] In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0142] Those skilled in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0143] In the embodiments provided by the present 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 only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0144] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0145] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0146] If the integrated module / unit is implemented in the form of 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, the present invention implements all or part of the processes in the above-mentioned implementation method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned various methods and device implementation methods. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium.

[0147] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for locating harmonic sources in a distribution network, characterized in that: include: Acquire a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes; Performing waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate; Determining whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate; When a harmonic source is connected, multiple node current pairs are extracted, and the area where the harmonic source is located is determined based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

2. The method for locating harmonic sources in a distribution network according to claim 1, characterized in that: The performing waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively to obtain a first voltage distortion rate and a second voltage distortion rate includes: Acquire a fundamental frequency, wherein the fundamental frequency is a frequency of a main power supply output voltage; The following steps are performed for the first voltage waveform data queue and the second voltage waveform data queue respectively: Extracting the fundamental wave amplitude and the fundamental wave phase from the voltage waveform data queue according to the fundamental wave frequency, and performing difference calculation according to the fundamental wave amplitude, the fundamental wave phase and the voltage waveform data queue to generate a harmonic data queue; generating a total harmonic amplitude according to the harmonic data queue; The ratio of the total harmonic amplitude to the fundamental amplitude is taken as the voltage distortion rate.

3. The method for locating harmonic sources in a distribution network according to claim 2, characterized in that: The extracting the fundamental wave amplitude and the fundamental wave phase of the voltage waveform data queue according to the fundamental wave frequency, and performing a difference operation according to the fundamental wave amplitude, the fundamental wave phase and the voltage waveform data queue to generate a harmonic data queue, including: Generate a harmonic data queue according to a first formula, wherein the first formula is: Wherein, UA is the cosine component of the fundamental amplitude, QD(Wn) is the Wnth data in the voltage waveform data queue, WnWax is the total number of data in the voltage waveform data queue, cos() is the cosine function, sin() is the sine function, ω0 is the fundamental frequency, TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, UB is the sine component of the fundamental amplitude, U0 is the fundamental amplitude, α is the fundamental phase, arccos() is the inverse cosine function, HQD(Wn) is the Wnth data in the harmonic data queue, and π is pi.

4. The method for locating harmonic sources in a distribution network according to claim 2, characterized in that: Generating the total harmonic amplitude according to the harmonic data queue includes: The total harmonic amplitude is generated according to a second formula, wherein the second formula is: Where TN is the number of data in the voltage waveform data queue corresponding to the fundamental cycle length, WnMax is the total number of data in the voltage waveform data queue, HQD(Wn) is the Wnth data in the harmonic data queue, and U N is the total harmonic amplitude.

5. The method for locating harmonic sources in a distribution network according to claim 1, characterized in that: The determining, according to the first voltage distortion rate and the second voltage distortion rate, whether a harmonic source is connected to the distribution network includes: The harmonic distortion change rate is determined according to a third formula, the first voltage distortion rate, and the second voltage distortion rate, wherein the third formula is: Where ξ is the harmonic distortion change rate, U thd,t is the second voltage distortion rate, U thd,t-1 is the first voltage distortion rate; If the harmonic distortion change rate is greater than the change rate threshold, it is determined that a harmonic source is connected to the distribution network.

6. The method for locating harmonic sources in a distribution network according to any one of claims 1 to 5, characterized in that: The determining the region where the harmonic source is located according to the plurality of node current pairs comprises: Obtain the time when the harmonic source is connected to the distribution network; Extracting node currents of the plurality of nodes before and after the harmonic source is connected to the distribution network, and constructing the plurality of node currents into a plurality of node current pairs according to correspondence with the nodes; Determine a plurality of current variation amounts according to the plurality of current pairs, wherein each current variation amount corresponds to a node; According to the line distance between the node and the main power supply, the multiple current changes are constructed into a change queue; Sequentially taking out current variation from the variation queue as variation to be analyzed; If the variation to be analyzed is the first current variation in the variation queue and the ratio of the variation to be analyzed to each second variation is greater than the first ratio, the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the second variation is the current variation after the variation to be analyzed in the variation queue; If the variation to be analyzed is the current variation after the first current variation in the variation queue, the deviation between the variation to be analyzed and the first variation is less than the current deviation threshold, and the ratio between the variation to be analyzed and each second variation is greater than the first ratio, then the area of ​​the node corresponding to the variation to be analyzed is used as the area where the harmonic source is located, wherein the first variation is the current variation in the variation queue that is one position before the variation to be analyzed; Otherwise, if the traversal of the variation queue is not completed, the process jumps to the step of sequentially taking out the current variation from the variation queue as the variation to be analyzed.

7. The method for locating harmonic sources in a distribution network according to claim 6, characterized in that: The step of determining a plurality of current variation amounts according to the plurality of current pairs comprises: For each current pair, the current variation is determined according to the fourth formula, wherein the fourth formula is: ΔI m =I post,m -I pre,m In the formula, ΔI m is the current change of the mth node, i post,m is the current of the mth node before the harmonic source is connected to the distribution network, I pre,m is the current of the mth node before the harmonic source is connected to the distribution network.

8. A device for locating harmonic sources in a distribution network, characterized in that: Used to implement the method for locating a harmonic source in a distribution network as described in any one of claims 1 to 7, the distribution network harmonic source locating device comprises: A data acquisition module, used for acquiring a first voltage waveform data queue and a second voltage waveform data queue corresponding to two adjacent time nodes; A voltage distortion analysis module, used to perform waveform distortion analysis on the first voltage waveform data queue and the second voltage waveform data queue respectively, to obtain a first voltage distortion rate and a second voltage distortion rate; A harmonic source access determination module, used to determine whether a harmonic source is connected to the distribution network according to the first voltage distortion rate and the second voltage distortion rate; as well as, The harmonic source positioning module is used to extract multiple node current pairs when a harmonic source is connected, and determine the area where the harmonic source is located based on the multiple node current pairs, wherein each node current pair corresponds to a node, and the node current pair includes the node current before and after the harmonic source is connected, and the distribution network is divided into multiple areas through multiple nodes.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method as claimed in any one of claims 1 to 7 are implemented.

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