Harmonic traceability method, device and harmonic traceability system

Abstract

The application provides a harmonic tracing method, a harmonic tracing device and a harmonic tracing system. The method comprises the following steps: obtaining a plurality of first current values and a plurality of first phase angles; obtaining a plurality of second current values and a plurality of second phase angles; and determining a harmonic direction according to the plurality of first current values, the plurality of second current values, the plurality of first phase angles and the plurality of second phase angles. In the scheme, two detection devices are added in the power grid to detect the harmonic current values on the alternating current line and the corresponding phase angles. Since the harmonic is continuously transmitted in the power grid and is dynamic, the harmonic is collected or flows out to other devices during the transmission process. The corresponding current values are different when the harmonic flows in and out dynamically, and the corresponding phase angles are also different. Therefore, the harmonic direction can be determined according to the current value and the phase angle.

Description

Technical Field

[0001] This application relates to the field of power grid power quality technology, and more specifically, to a harmonic source tracing method, apparatus, computer-readable storage medium, and harmonic source tracing system. Background Technology

[0002] With the construction of new power systems, a large number of power electronic devices are gradually being connected to the existing AC / DC power grids. The harmonics generated by these devices also flow into the AC / DC power grids, where they are amplified and concentrated, having an increasingly significant impact on the grid. Harmonics increase the losses of critical power equipment, causing equipment to overheat, vibrate, and generate harmonics, and can even lead to equipment burnout.

[0003] In traditional power systems, harmonic mitigation primarily addresses the issue by controlling harmonic sources. This involves configuring active and passive filters to absorb harmonics from their sources and prevent them from flowing into the AC system. However, these methods cannot guarantee 100% absorption of harmonic currents; some harmonics will inevitably flow into the AC system. This small amount of harmonics flowing into the AC system is amplified and aggregated by the complex power grid, impacting the power system. This impact becomes increasingly pronounced with the integration of power electronic equipment, and in severe cases, can even lead to the shutdown of some AC equipment and DC systems. Therefore, current solutions often fail to determine the direction of harmonics, resulting in low efficiency in subsequent harmonic mitigation. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, computer-readable storage medium, and harmonic source tracing system to at least solve the problem in the prior art that the direction of harmonics cannot be determined, resulting in low efficiency of subsequent harmonic control.

[0005] To achieve the above objectives, according to one aspect of this application, a method for tracing the source of harmonics is provided, comprising: acquiring a plurality of first current values ​​and a plurality of first phase angles, wherein the first current values ​​are current values ​​of harmonic currents on an AC line collected by a first detection device, and the first phase angles are phase angles of the harmonic currents on the AC line collected by the first detection device, the first current values ​​corresponding one-to-one with the AC line, and the first phase angles corresponding one-to-one with the AC line; acquiring a plurality of second current values ​​and a plurality of second phase angles, wherein the second current values ​​are current values ​​of the harmonic currents on the AC line collected by a second detection device, and the second phase angles are phase angles of the harmonic currents on the AC line collected by the second detection device, the second current values ​​corresponding one-to-one with the AC line, and the second phase angles corresponding one-to-one with the AC line; and determining the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0006] Optionally, determining the harmonic direction based on a plurality of first current values, a plurality of second current values, a plurality of first phase angles, and a plurality of second phase angles includes: determining the largest first current value among the plurality of first current values ​​as a first target current value; determining the largest second current value among the plurality of second current values ​​other than the second target current value as a third target current value, wherein the second target current value is one of the second current values, and the AC line corresponding to the second target current value is the same as the AC line corresponding to the first target current value; calculating the phase difference between the first target phase angle and the second target phase angle, and determining the harmonic direction based on the phase difference, wherein the first target phase angle is the first phase angle corresponding to the first target current value, and the second target phase angle is the second phase angle corresponding to the third target current value.

[0007] Optionally, before determining the largest first current value among multiple first current values ​​as the first target current value, the method further includes: when there are at least two first target current values, selecting one AC line that meets a preset condition from the AC lines corresponding to the at least two first target current values ​​as the first target AC line, wherein the preset condition includes at least one of the following: the number of times the first target current value of the AC line is greater than a preset threshold within a historical time period is greater than a preset number; the transmission rate of the AC line is lower than a preset rate; the fluctuation range of the AC line is greater than a preset fluctuation range; the instantaneous fluctuation degree of the AC line is greater than a preset fluctuation degree; when there are at least two third target current values, selecting one AC line that meets the preset condition from the AC lines corresponding to the at least two third target current values ​​as the second target AC line.

[0008] Optionally, determining the harmonic direction based on the phase difference includes: sequentially executing target steps until the harmonic direction of all the AC lines has been determined, wherein the target step is: selecting a first target AC line and a second target AC line from the plurality of AC lines; if the phase difference is within a preset range, determining the harmonic direction of the first target AC line and the second target AC line as the outflow direction; if the phase difference is not within the preset range, determining the harmonic direction of the first target AC line and the second target AC line as the inflow direction, wherein the first target AC line is the AC line corresponding to the first target phase angle for which the harmonic direction has not been determined, and the second target AC line is the AC line corresponding to the second target phase angle for which the harmonic direction has not been determined.

[0009] Optionally, after determining the harmonic direction based on the phase difference, the method further includes: determining that the harmonic direction is abnormal when the harmonic directions of the two connected AC lines are the same; and determining that the harmonic direction is normal when the harmonic directions of the two connected AC lines are not the same.

[0010] Optionally, after determining the harmonic direction based on the phase difference, the method further includes: marking the harmonic direction of each AC line accordingly to obtain multiple marking information; and, when all the AC lines have been marked, constructing the power grid harmonic power flow direction based on the multiple marking information.

[0011] Optionally, after determining the harmonic direction, the method further includes: obtaining the harmonic order of the AC line; obtaining a reference current value of the AC line; and determining the degree of anomalousness of the AC line harmonics based on the harmonic order and / or the current difference, wherein the current difference is the difference between the reference current value and the current value of the harmonic current.

[0012] According to another aspect of this application, a harmonic tracing device is provided, comprising: a first acquisition unit, configured to acquire a plurality of first current values ​​and a plurality of first phase angles, wherein the first current values ​​are current values ​​of harmonic currents on an AC line collected by a first detection device, and the first phase angles are phase angles of the harmonic currents on the AC line collected by the first detection device, wherein the first current values ​​correspond one-to-one with the AC line, and the first phase angles correspond one-to-one with the AC line; a second acquisition unit, configured to acquire a plurality of second current values ​​and a plurality of second phase angles, wherein the second current values ​​are current values ​​of the harmonic currents on the AC line collected by a second detection device, and the second phase angles are phase angles of the harmonic currents on the AC line collected by the second detection device, wherein the second current values ​​correspond one-to-one with the AC line, and the second phase angles correspond one-to-one with the AC line; and a first determination unit, configured to determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the harmonic source tracing methods described above.

[0014] According to another aspect of this application, a harmonic source tracing system is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any of the harmonic source tracing methods described herein.

[0015] By applying the technical solution of this application, two detection devices are added to the power grid to detect the harmonic current value and the corresponding phase angle on the AC line. Since harmonics are continuously transmitted in the power grid and are dynamic, they will converge or flow out to other devices during the transmission process. The current value and the corresponding phase angle are different when harmonics flow in and out dynamically. Therefore, the direction of harmonics can be determined based on the magnitude of the current and the magnitude of the phase angle. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for performing a harmonic source tracing method according to an embodiment of this application is shown.

[0018] Figure 2 A schematic flowchart of a harmonic source tracing method provided according to an embodiment of this application is shown;

[0019] Figure 3 A partial structural schematic diagram of the substation is shown;

[0020] Figure 4 A structural block diagram of a harmonic tracing device provided according to an embodiment of this application is shown.

[0021] The above figures include the following reference numerals:

[0022] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 10. First detection device; 20. Second detection device. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] Harmonics flowing in AC / DC power grids can be controlled by deploying filters in local areas. However, for AC / DC power grids, the direction of harmonic flow is crucial, and a reasonable and simple mathematical method must be used to determine the direction of harmonic flow in real time.

[0027] As described in the background section, a small amount of harmonics flowing into the AC system in the prior art can also affect the power system after being gathered and amplified by the complex large power grid. This effect becomes more and more obvious with the connection of power electronic equipment, and in severe cases, it can even lead to the shutdown of some AC equipment and DC systems. In order to solve the problem that the direction of harmonics cannot be determined, resulting in low efficiency of subsequent harmonic control, the embodiments of this application provide a harmonic source tracing method, device, computer-readable storage medium and harmonic source tracing system.

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a harmonic source tracing method according to an embodiment of the present invention. For example... Figure 1 As shown, a mobile terminal may include one or more ( Figure 1Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0030] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0031] This embodiment provides a method for tracing the source of harmonics running on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0032] Figure 2 This is a flowchart illustrating a harmonic source tracing method according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0033] Step S201: Obtain multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0034] Specifically, the harmonic currents on the AC lines of the substation can be sampled using a first detection device. This allows the acquisition of the current values ​​and phase angles of the harmonic currents on multiple AC lines in the substation. The maximum value, i.e., the current amplitude, is then selected from the multiple current values ​​on one AC line as the first current value. Furthermore, the harmonic current amplitude (first current value) and phase angle (first phase angle) on each AC line monitored by the first detection device can be recorded.

[0035] Specifically, the first current value and phase angle on each AC line can be recorded as: I n,k =I n,km ∠θ n,km Where n is the harmonic order, k is the node identifier of the AC line, and I n,k I represents the nth harmonic current of the k-th AC line. n,km θ represents the nth current amplitude (first current value) on the k-th AC line. n,km This represents the phase angle of the m-th harmonic on the k-th AC line.

[0036] Specifically, such as Figure 3 As shown, the first detection device 10 is connected to the busbar of the substation. The first detection device 10 can be any feasible harmonic monitoring device, such as a harmonic monitor or a GDON-500C harmonic online monitoring device.

[0037] Step S202: Obtain multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0038] Specifically, the harmonic currents on the AC lines of the substation can also be sampled using a second detection device. This allows the current values ​​and phase angles of the harmonic currents on multiple AC lines of the substation to be obtained. Then, the maximum value, i.e. the current amplitude, is selected from the multiple current values ​​on an AC line as the second current value.

[0039] Specifically, the second current value and phase angle on each AC line can be recorded as: I n,kr =I n,krm ∠θ n,krm Where kr is the node identifier of the AC line, I n,kr I represents the nth harmonic current of the kr-th AC line. n,krm θ represents the nth current amplitude (second current value) on the kr-th AC line. n,krm This represents the phase angle of the m-th harmonic on the kr-th AC line.

[0040] Specifically, such as Figure 3 Therefore, the second detection device 20 is connected to the bus of the substation. The second detection device 20 can be any feasible reactive power compensation device, such as a passive power filter or a static var compensator.

[0041] Step S203: Determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0042] Specifically, given multiple first current values, multiple second current values, multiple first phase angles, and multiple second phase angles, these four parameters are combined to ultimately determine the harmonic direction. The current values ​​and corresponding phase angles are different when the harmonics dynamically flow in and out, so the harmonic direction can be determined based on the magnitude of the current and the magnitude of the phase angle.

[0043] In this embodiment, two detection devices are added to the power grid to detect the harmonic current value and the corresponding phase angle on the AC line. Since harmonics are continuously transmitted in the power grid and are dynamic, they will converge or flow out to other devices during transmission. The current value and the corresponding phase angle are different when harmonics flow in and out dynamically. Therefore, the direction of harmonics can be determined based on the magnitude of the current and the magnitude of the phase angle.

[0044] Specifically, this application proposes a harmonic source tracing method based on harmonic current measurement, which can be used to determine the direction of harmonic power flow. It can be applied in actual AC / DC power grids to quickly identify harmonic directions and achieve the purpose of harmonic source tracing.

[0045] To further accurately determine the harmonic direction, in the specific implementation process, the harmonic direction is determined based on multiple first current values, multiple second current values, multiple first phase angles, and multiple second phase angles. This can be achieved through the following steps: The largest of the multiple first current values ​​is determined as the first target current value; the largest of the multiple second current values ​​(excluding the second target current value) is determined as the third target current value, wherein the second target current value is one of the second current values, and the AC line corresponding to the second target current value is the same as the AC line corresponding to the first target current value; the phase difference between the first target phase angle and the second target phase angle is calculated, and the harmonic direction is determined based on the phase difference, wherein the first target phase angle is the first phase angle corresponding to the first target current value, and the second target phase angle is the second phase angle corresponding to the third target current value.

[0046] In this scheme, after obtaining the first current value on each line, the largest harmonic can be selected from multiple first current values ​​to obtain the first target current value. If the maximum value of the first current value detected by the first detection device is the same as the maximum value of the second current value detected by the second detection device, the maximum value of the second current value is first determined as the second target current value. Then, the maximum value among multiple second current values ​​other than the second target current value is determined as the third target current value. In this way, the AC lines selected by the first detection device and the second detection device are the same, which further ensures that this scheme can use two AC lines to determine the harmonic direction.

[0047] Of course, if the AC line with the first current value detected by the first detection device is different from the AC line with the second current value detected by the second detection device, then the phase difference can be calculated using the AC line with the first current value detected by the first detection device and the AC line with the second current value detected by the second detection device.

[0048] Specifically, the first target current value corresponding to the AC circuit can be denoted as: I n,k0 =I n,k0m ∠θ n,k0m Where k0 is the node identifier of the AC line corresponding to the first target current value, I n,k0 I represents the nth harmonic current of the k0th AC line. n,k0m θ represents the nth current amplitude (first current value) on the k0th AC line. n,k0m This represents the phase angle of the m-th harmonic on the k0-th AC line.

[0049] Specifically, the formula for calculating the phase difference is: Δθ 0r =θ n,k0m -θ n,krm.

[0050] In the case where at least two AC lines have the same maximum first current value and at least two AC lines have the same maximum second current value, in the specific implementation process, before determining the largest of the multiple first current values ​​as the first target current value, the method further includes the following steps: when there are at least two first target current values, selecting one AC line that meets a preset condition from the AC lines corresponding to the at least two first target current values ​​as the first target AC line, wherein the preset condition includes at least one of the following: the number of times the first target current value of the AC line is greater than a preset threshold in the historical time period is greater than a preset number; the transmission rate of the AC line is lower than a preset rate; the fluctuation range of the AC line is greater than a preset fluctuation range; the instantaneous fluctuation degree of the AC line is greater than a preset fluctuation degree; when there are at least two third target current values, selecting one AC line that meets the preset condition from the AC lines corresponding to the at least two third target current values ​​as the second target AC line.

[0051] In this scheme, when selecting a target AC line (selecting the first target AC line and the second target AC line) from multiple AC lines, if there are two or more lines with the same maximum harmonic amplitude, the selection can be made based on whether the AC line meets the preset conditions. In this way, the selected target AC line has more harmonic characteristics, which can further ensure that the harmonic direction obtained later is more accurate.

[0052] Specifically, the preset conditions are not limited to the above-mentioned types, but can be any other feasible preset conditions in the prior art. The target AC line can be selected based on one of the preset conditions, or multiple preset conditions can be combined to select the target AC line.

[0053] To determine the harmonic direction for all AC lines in a substation, this application's method of determining the harmonic direction based on the aforementioned phase difference can be achieved through the following steps: sequentially executing the target steps until the harmonic direction for all the aforementioned AC lines has been determined. The target steps are: selecting a first target AC line and a second target AC line from among the multiple AC lines; determining the harmonic direction of the first target AC line and the second target AC line as the outflow direction when the phase difference is within a preset range; and determining the harmonic direction of the first target AC line and the second target AC line as the inflow direction when the phase difference is not within the preset range. The first target AC line is the AC line corresponding to the first target phase angle for which the harmonic direction has not been determined, and the second target AC line is the AC line corresponding to the second target phase angle for which the harmonic direction has not been determined.

[0054] In this scheme, the harmonic direction of each AC line can be determined sequentially until the harmonic direction of all AC lines has been determined. In this way, the harmonic direction of all AC lines in the substation can be determined sequentially.

[0055] For example, there are 6 AC lines, namely A, B, C, D, E, and F. When selecting AC lines for the first time, the current values ​​of A and D are the largest, so the harmonic directions of A and D are determined. Then, the two AC lines with the largest current values ​​are selected from B, C, E, and F. For example, the current values ​​of B and C are the largest, so the harmonic directions of B and C are determined. Finally, the harmonic directions of E and F are determined.

[0056] Specifically, the preset range can be -90° to 90°, if -90° ≤ Δθ 0r If the angle is ≤90°, the harmonic direction is determined as inflow; otherwise, it is outflow. This is the calculation process for the harmonic direction of a single AC line. If there are multiple AC lines, first calculate the phase angle difference Δθ = θ between each pair of AC lines. n,kim -θ n,k0m If Δθ=θ n,kim -θ n,k0m The direction of harmonics is determined as inflow; otherwise, it is outflow.

[0057] To avoid detecting anomalies and further ensure the high effectiveness of this solution, after determining the harmonic direction based on the phase difference, the method further includes the following steps: if the harmonic directions of the two connected AC lines are the same, the harmonic direction is determined to be abnormal; if the harmonic directions of the two connected AC lines are not the same, the harmonic direction is determined to be normal.

[0058] In this scheme, if both directly connected AC lines are either inflows or outflows, then the harmonic direction is abnormal, possibly due to a substation malfunction or reversed installation. Therefore, for AC lines, there should be one inflow and one outflow. This embodiment can further determine the accuracy of the harmonic direction.

[0059] Specifically, such as Figure 3 As shown, AC line 1 and AC line 5 are connected by a circuit breaker. If the harmonic directions of AC line 1 and AC line 5 are the same, then the corresponding harmonic directions of AC line 1 and AC line 5 are abnormal. It should be noted that the determination of whether the harmonic direction is abnormal is based on two directly connected AC lines, while the previous determination of the harmonic direction was based on two non-directly connected AC lines, as shown in... Figure 3 As shown, the first target AC line obtained by the first detection device should be one of AC line 1, AC line 2, AC line 3, and AC line 4, and the second target AC line obtained by the second detection device should be one of AC line 5, AC line 6, AC line 7, and AC line 8.

[0060] In some embodiments, after determining the harmonic direction based on the phase difference, the method further includes the following steps: marking the harmonic direction of each of the AC lines to obtain multiple marking information; and constructing the power grid harmonic flow direction based on the multiple marking information when all the AC lines have been marked.

[0061] In this scheme, after marking the direction of each AC line in sequence, the harmonic power flow direction of the entire power grid can be determined directly and quickly.

[0062] In some embodiments, after determining the harmonic direction, the method further includes the following steps: obtaining the harmonic order of the AC line; obtaining the reference current value of the AC line; and determining the degree of anomalousness of the AC line harmonics based on the harmonic order and / or the current difference, wherein the current difference is the difference between the reference current value and the current value of the harmonic current.

[0063] In this scheme, after determining the direction of harmonics, the degree of harmonic abnormality of the AC line can also be determined. This can be done based on the harmonic order, the current difference, or the harmonic order. This allows for the determination of the degree of harmonic abnormality of the AC line, ensuring that it can be used as a reference for staff in the future.

[0064] Specifically, the harmonic anomaly level of the AC line can be determined as the first anomaly level when the harmonic number is greater than the first threshold, or the harmonic anomaly level of the AC line can be determined as the second anomaly level when the harmonic number is greater than the second threshold, or the harmonic anomaly level of the AC line can be determined as the third anomaly level when the harmonic number is greater than the third threshold, wherein the first threshold < the second threshold < the third threshold.

[0065] Specifically, the harmonic anomaly level of the AC line can be determined as the first anomaly level when the current difference is greater than the first difference threshold, or the harmonic anomaly level of the AC line can be determined as the second anomaly level when the current difference is greater than the second difference threshold, or the harmonic anomaly level of the AC line can be determined as the third anomaly level when the current difference is greater than the third difference threshold, wherein the first difference threshold is less than the second difference threshold and less than the third difference threshold.

[0066] Specifically, the degree of harmonic anomaly in an AC line can also be determined by combining the harmonic order and the current difference. Several scenarios are described below:

[0067] When the harmonic order is greater than the first threshold and the current difference is greater than the first difference threshold, the harmonic anomaly level of the AC line is determined to be the first anomaly level.

[0068] When the harmonic order is greater than the first threshold and the current difference is greater than the second threshold, the harmonic anomaly level of the AC line is determined to be the first anomaly level.

[0069] When the harmonic order is greater than the first threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0070] When the harmonic order is greater than the second threshold and the current difference is greater than the first threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0071] When the harmonic order is greater than the second threshold and the current difference is greater than the second difference threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0072] When the harmonic order is greater than the second threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the third anomaly level.

[0073] When the harmonic order is greater than the third threshold and the current difference is greater than the first difference threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0074] When the harmonic order is greater than the third threshold and the current difference is greater than the second threshold, the harmonic anomaly of the AC line is determined to be the third anomaly.

[0075] When the harmonic order is greater than the second threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the third anomaly level.

[0076] This application also provides a harmonic tracing device. It should be noted that the harmonic tracing device of this application can be used to execute the harmonic tracing method provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0077] The following describes the harmonic tracing device provided in the embodiments of this application.

[0078] Figure 4 This is a structural block diagram of a harmonic tracing device according to an embodiment of this application. Figure 4 As shown, the device includes:

[0079] The first acquisition unit 100 is used to acquire multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0080] Specifically, the harmonic currents on the AC lines of the substation can be sampled using a first detection device. This allows the acquisition of the current values ​​and phase angles of the harmonic currents on multiple AC lines in the substation. The maximum value, i.e., the current amplitude, is then selected from the multiple current values ​​on one AC line as the first current value. Furthermore, the harmonic current amplitude (first current value) and phase angle (first phase angle) on each AC line monitored by the first detection device can be recorded.

[0081] Specifically, the first current value and phase angle on each AC line can be recorded as: I n,k =I n,km ∠θ n,km Where n is the harmonic order, k is the node identifier of the AC line, and I n,k I represents the nth harmonic current of the k-th AC line. n,km θ represents the nth current amplitude (first current value) on the k-th AC line. n,km This represents the phase angle of the m-th harmonic on the k-th AC line.

[0082] Specifically, such as Figure 3 As shown, the first detection device is connected to the busbar of the substation. The first detection device can be any feasible harmonic monitoring device, such as a harmonic monitor or a GDON-500C harmonic online monitoring device.

[0083] The second acquisition unit 200 is used to acquire multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0084] Specifically, the harmonic currents on the AC lines of the substation can also be sampled using a second detection device. This allows the current values ​​and phase angles of the harmonic currents on multiple AC lines of the substation to be obtained. Then, the maximum value, i.e. the current amplitude, is selected from the multiple current values ​​on an AC line as the second current value.

[0085] Specifically, the second current value and phase angle on each AC line can be recorded as: I n,kr =I n,krm ∠θ n,krm Where kr is the node identifier of the AC line, I n,kr I represents the nth harmonic current of the kr-th AC line. n,krm θ represents the nth current amplitude (second current value) on the kr-th AC line. n,krm This represents the phase angle of the m-th harmonic on the kr-th AC line.

[0086] Specifically, such as Figure 3 Therefore, the second detection device is connected to the busbar of the substation. The second detection device can be any feasible reactive power compensation device, such as a passive power filter or a static var compensator.

[0087] The first determining unit 300 is used to determine the harmonic direction based on a plurality of the aforementioned first current values, a plurality of the aforementioned second current values, a plurality of the aforementioned first phase angles, and a plurality of the aforementioned second phase angles.

[0088] Specifically, given multiple first current values, multiple second current values, multiple first phase angles, and multiple second phase angles, these four parameters are combined to ultimately determine the harmonic direction. The current values ​​and corresponding phase angles are different when the harmonics dynamically flow in and out, so the harmonic direction can be determined based on the magnitude of the current and the magnitude of the phase angle.

[0089] In this embodiment, two detection devices are added to the power grid to detect the harmonic current value and the corresponding phase angle on the AC line. Since harmonics are continuously transmitted in the power grid and are dynamic, they will converge or flow out to other devices during transmission. The current value and the corresponding phase angle are different when harmonics flow in and out dynamically. Therefore, the direction of harmonics can be determined based on the magnitude of the current and the magnitude of the phase angle.

[0090] Specifically, this application proposes a harmonic source tracing method based on harmonic current measurement, which can be used to determine the direction of harmonic power flow. It can be applied in actual AC / DC power grids to quickly identify harmonic directions and achieve the purpose of harmonic source tracing.

[0091] To further accurately determine the harmonic direction, in the specific implementation process, the first determining unit includes a first determining module, a second determining module, and a third determining module. The first determining module is used to determine the largest of the multiple first current values ​​as the first target current value. The second determining module is used to determine the largest of the multiple second current values ​​other than the second target current value as the third target current value. The second target current value is one of the second current values, and the AC line corresponding to the second target current value is the same as the AC line corresponding to the first target current value. The third determining module is used to calculate the phase difference between the first target phase angle and the second target phase angle, and determine the harmonic direction based on the phase difference. The first target phase angle is the first phase angle corresponding to the first target current value, and the second target phase angle is the second phase angle corresponding to the third target current value.

[0092] In this scheme, after obtaining the first current value on each line, the largest harmonic can be selected from multiple first current values ​​to obtain the first target current value. If the maximum value of the first current value detected by the first detection device is the same as the maximum value of the second current value detected by the second detection device, the maximum value of the second current value is first determined as the second target current value. Then, the maximum value among multiple second current values ​​other than the second target current value is determined as the third target current value. In this way, the AC lines selected by the first detection device and the second detection device are the same, which further ensures that this scheme can use two AC lines to determine the harmonic direction.

[0093] Of course, if the AC line with the first current value detected by the first detection device is different from the AC line with the second current value detected by the second detection device, then the phase difference can be calculated using the AC line with the first current value detected by the first detection device and the AC line with the second current value detected by the second detection device.

[0094] Specifically, the first target current value corresponding to the AC circuit can be denoted as: I n,k0 =I n,k0m ∠θ n,k0m Where k0 is the node identifier of the AC line corresponding to the first target current value, I n,k0 I represents the nth harmonic current of the k0th AC line. n,k0m θ represents the nth current amplitude (first current value) on the k0th AC line. n,k0m This represents the phase angle of the m-th harmonic on the k0-th AC line.

[0095] Specifically, the formula for calculating the phase difference is: Δθ 0r =θ n,k0m -θ n,krm .

[0096] In the case where at least two AC lines have the same and maximum first current value, and at least two AC lines have the same and maximum second current value, the device further includes a first processing unit and a second processing unit. The first processing unit, before determining the largest of the multiple first current values ​​as the first target current value, selects an AC line that meets preset conditions from the AC lines corresponding to at least two first target current values ​​as the first target AC line, provided there are at least two first target current values. The preset conditions include at least one of the following: the number of times the first target current value of the AC line exceeds a preset threshold within a historical time period exceeds a preset number; the transmission rate of the AC line is lower than a preset rate; the fluctuation range of the AC line is greater than a preset fluctuation range; or the instantaneous fluctuation degree of the AC line is greater than a preset fluctuation degree. The second processing unit, when there are at least two third target current values, selects an AC line that meets the preset conditions from the AC lines corresponding to at least two third target current values ​​as the second target AC line.

[0097] In this scheme, when selecting a target AC line (selecting the first target AC line and the second target AC line) from multiple AC lines, if there are two or more lines with the same maximum harmonic amplitude, the selection can be made based on whether the AC line meets the preset conditions. In this way, the selected target AC line has more harmonic characteristics, which can further ensure that the harmonic direction obtained later is more accurate.

[0098] Specifically, the preset conditions are not limited to the above-mentioned types, but can be any other feasible preset conditions in the prior art. The target AC line can be selected based on one of the preset conditions, or multiple preset conditions can be combined to select the target AC line.

[0099] In order to determine the harmonic direction of all AC lines in a substation, the third determination module of this application includes an execution submodule. The execution submodule is used to sequentially execute the target steps until the harmonic direction of all the aforementioned AC lines has been determined. The target steps are as follows: selecting a first target AC line and a second target AC line from a plurality of the aforementioned AC lines; if the phase difference is within a preset range, determining the harmonic direction of the first target AC line and the second target AC line as the outflow direction; if the phase difference is not within the preset range, determining the harmonic direction of the first target AC line and the second target AC line as the inflow direction. The first target AC line is the AC line corresponding to the first target phase angle for which the harmonic direction has not been determined, and the second target AC line is the AC line corresponding to the second target phase angle for which the harmonic direction has not been determined.

[0100] In this scheme, the harmonic direction of each AC line can be determined sequentially until the harmonic direction of all AC lines has been determined. In this way, the harmonic direction of all AC lines in the substation can be determined sequentially.

[0101] For example, there are 6 AC lines, namely A, B, C, D, E, and F. When selecting AC lines for the first time, the current values ​​of A and D are the largest, so the harmonic directions of A and D are determined. Then, the two AC lines with the largest current values ​​are selected from B, C, E, and F. For example, the current values ​​of B and C are the largest, so the harmonic directions of B and C are determined. Finally, the harmonic directions of E and F are determined.

[0102] Specifically, the preset range can be -90° to 90°, if -90° ≤ Δθ 0r If the angle is ≤90°, the harmonic direction is determined as inflow; otherwise, it is outflow. This is the calculation process for the harmonic direction of a single AC line. If there are multiple AC lines, first calculate the phase angle difference Δθ = θ between each pair of AC lines. n,kim -θ n,k0m If Δθ=θ n,kim -θ n,k0m The direction of harmonics is determined as inflow; otherwise, it is outflow.

[0103] To avoid detecting anomalies and further ensure the high effectiveness of this solution, the above-mentioned device also includes a second determining unit and a third determining unit. The second determining unit is used to determine that the harmonic direction is abnormal when the harmonic directions of the two connected AC lines are the same after determining the harmonic direction based on the phase difference. The third determining unit is used to determine that the harmonic direction is normal when the harmonic directions of the two connected AC lines are not the same.

[0104] In this scheme, if both directly connected AC lines are either inflows or outflows, then the harmonic direction is abnormal, possibly due to a substation malfunction or reversed installation. Therefore, for AC lines, there should be one inflow and one outflow. This embodiment can further determine the accuracy of the harmonic direction.

[0105] Specifically, such as Figure 3 As shown, AC line 1 and AC line 5 are connected by a circuit breaker. If the harmonic directions of AC line 1 and AC line 5 are the same, then the corresponding harmonic directions of AC line 1 and AC line 5 are abnormal. It should be noted that the determination of whether the harmonic direction is abnormal is based on two directly connected AC lines, while the previous determination of the harmonic direction was based on two non-directly connected AC lines, as shown in... Figure 3 As shown, the first target AC line obtained by the first detection device should be one of AC line 1, AC line 2, AC line 3, and AC line 4, and the second target AC line obtained by the second detection device should be one of AC line 5, AC line 6, AC line 7, and AC line 8.

[0106] In some embodiments, the above-described apparatus further includes a marking unit and a construction unit. The marking unit is used to mark the harmonic direction of each of the AC lines after determining the harmonic direction based on the phase difference, thereby obtaining multiple marking information. The construction unit is used to construct the power grid harmonic power flow direction based on the multiple marking information when all the AC lines have been marked.

[0107] In this scheme, after marking the direction of each AC line in sequence, the harmonic power flow direction of the entire power grid can be determined directly and quickly.

[0108] In some embodiments, the above-described apparatus further includes a third acquisition unit, a fourth acquisition unit, and a fourth determination unit. The third acquisition unit is used to acquire the harmonic order of the AC line after determining the harmonic direction. The fourth acquisition unit is used to acquire a reference current value of the AC line. The fourth determination unit is used to determine the degree of aberration of the harmonics in the AC line by the harmonic order and / or the current difference, wherein the current difference is the difference between the reference current value and the current value of the harmonic current.

[0109] In this scheme, after determining the direction of harmonics, the degree of harmonic abnormality of the AC line can also be determined. This can be done based on the harmonic order, the current difference, or the harmonic order. This allows for the determination of the degree of harmonic abnormality of the AC line, ensuring that it can be used as a reference for staff in the future.

[0110] Specifically, the harmonic anomaly level of the AC line can be determined as the first anomaly level when the harmonic number is greater than the first threshold, or the harmonic anomaly level of the AC line can be determined as the second anomaly level when the harmonic number is greater than the second threshold, or the harmonic anomaly level of the AC line can be determined as the third anomaly level when the harmonic number is greater than the third threshold, wherein the first threshold < the second threshold < the third threshold.

[0111] Specifically, the harmonic anomaly level of the AC line can be determined as the first anomaly level when the current difference is greater than the first difference threshold, or the harmonic anomaly level of the AC line can be determined as the second anomaly level when the current difference is greater than the second difference threshold, or the harmonic anomaly level of the AC line can be determined as the third anomaly level when the current difference is greater than the third difference threshold, wherein the first difference threshold is less than the second difference threshold and less than the third difference threshold.

[0112] Specifically, the degree of harmonic anomaly in an AC line can also be determined by combining the harmonic order and the current difference. Several scenarios are described below:

[0113] When the harmonic order is greater than the first threshold and the current difference is greater than the first difference threshold, the harmonic anomaly level of the AC line is determined to be the first anomaly level.

[0114] When the harmonic order is greater than the first threshold and the current difference is greater than the second threshold, the harmonic anomaly level of the AC line is determined to be the first anomaly level.

[0115] When the harmonic order is greater than the first threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0116] When the harmonic order is greater than the second threshold and the current difference is greater than the first threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0117] When the harmonic order is greater than the second threshold and the current difference is greater than the second difference threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0118] When the harmonic order is greater than the second threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the third anomaly level.

[0119] When the harmonic order is greater than the third threshold and the current difference is greater than the first difference threshold, the harmonic anomaly level of the AC line is determined to be the second anomaly level.

[0120] When the harmonic order is greater than the third threshold and the current difference is greater than the second threshold, the harmonic anomaly of the AC line is determined to be the third anomaly.

[0121] When the harmonic order is greater than the second threshold and the current difference is greater than the third threshold, the harmonic anomaly level of the AC line is determined to be the third anomaly level.

[0122] The aforementioned harmonic tracing device includes a processor and a memory. The first acquisition unit, the second acquisition unit, and the first determination unit are all stored as program units in the memory. The processor executes the program units stored in the memory to achieve the corresponding functions. All of the above modules are located in the same processor; alternatively, the modules may be located in different processors in any combination.

[0123] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can address the problem in existing technologies where the direction of harmonics cannot be determined, leading to low efficiency in subsequent harmonic mitigation.

[0124] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0125] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the harmonic source tracing method.

[0126] Specifically, methods for tracing the source of harmonics include:

[0127] Step S201: Obtain multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0128] Step S202: Obtain multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0129] Step S203: Determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0130] This invention provides a processor for running a program, wherein the program executes the harmonic source tracing method.

[0131] Specifically, methods for tracing the source of harmonics include:

[0132] Step S201: Obtain multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0133] Step S202: Obtain multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0134] Step S203: Determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0135] This application also provides a harmonic tracing system, including one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include a method for performing any of the harmonic tracing methods described above.

[0136] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0137] Step S201: Obtain multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0138] Step S202: Obtain multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0139] Step S203: Determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0140] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0141] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0142] Step S201: Obtain multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line.

[0143] Step S202: Obtain multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line.

[0144] Step S203: Determine the harmonic direction based on the plurality of first current values, the plurality of second current values, the plurality of first phase angles, and the plurality of second phase angles.

[0145] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0146] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0147] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0148] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0149] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0150] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0151] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0152] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0153] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0154] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0155] 1) The harmonic source tracing method of this application adds two detection devices to the power grid to detect the harmonic current value and the corresponding phase angle on the AC line respectively. Since the harmonics are continuously transmitted in the power grid and are dynamic, they will converge or flow out to other equipment during the transmission process. The current value and the corresponding phase angle are different when the harmonics flow in and out dynamically. Therefore, the harmonic direction can be determined according to the current magnitude and phase angle.

[0156] 2) The harmonic source tracing device of this application adds two detection devices to the power grid to detect the harmonic current value and the corresponding phase angle on the AC line respectively. Since the harmonics are continuously transmitted in the power grid and are dynamic, they will converge or flow out to other equipment during the transmission process. The current value and the corresponding phase angle are different when the harmonics flow in and out dynamically. Therefore, the harmonic direction can be determined according to the current magnitude and phase angle.

[0157] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for tracing the source of harmonics, characterized in that, include: Multiple first current values ​​and multiple first phase angles are obtained, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line. Multiple second current values ​​and multiple second phase angles are obtained, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line. The harmonic direction is determined based on a plurality of first current values, a plurality of second current values, a plurality of first phase angles, and a plurality of second phase angles. Determining the harmonic direction based on multiple first current values, multiple second current values, multiple first phase angles, and multiple second phase angles includes: determining the largest first current value among the multiple first current values ​​as a first target current value; determining the largest second current value among the multiple second current values ​​other than the second target current value as a third target current value, wherein the second target current value is one of the second current values, and the AC line corresponding to the second target current value is the same as the AC line corresponding to the first target current value; calculating the phase difference between the first target phase angle and the second target phase angle, and determining the harmonic direction based on the phase difference, wherein the first target phase angle is the first phase angle corresponding to the first target current value, and the second target phase angle is the second phase angle corresponding to the third target current value.

2. The method according to claim 1, characterized in that, Before determining the largest of the plurality of first current values ​​as the first target current value, the method further includes: In the case of at least two first target current values, one AC line that meets a preset condition is selected from the AC lines corresponding to the at least two first target current values ​​as the first target AC line. The preset condition includes at least one of the following: the number of times the first target current value of the AC line is greater than a preset threshold within a historical time period is greater than a preset number; the transmission rate of the AC line is lower than a preset rate; the fluctuation range of the AC line is greater than a preset fluctuation range; and the instantaneous fluctuation degree of the AC line is greater than a preset fluctuation degree. In the case of at least two third target current values, one AC line that meets the preset condition is selected from the AC lines corresponding to the at least two third target current values ​​as the second target AC line.

3. The method according to claim 1, characterized in that, Determining the harmonic direction based on the phase difference includes: The target steps are executed sequentially until the harmonic directions of all the AC lines have been determined. The target steps are as follows: selecting a first target AC line and a second target AC line from the plurality of AC lines; if the phase difference is within a preset range, determining the harmonic directions of the first target AC line and the second target AC line as the outflow direction; if the phase difference is not within the preset range, determining the harmonic directions of the first target AC line and the second target AC line as the inflow direction. The first target AC line is the AC line corresponding to the first target phase angle for which the harmonic direction has not been determined, and the second target AC line is the AC line corresponding to the second target phase angle for which the harmonic direction has not been determined.

4. The method according to claim 1, characterized in that, After determining the harmonic direction based on the phase difference, the method further includes: If the harmonic directions of two connected AC lines are the same, the harmonic direction is determined to be abnormal. If the harmonic directions of two connected AC lines are not the same, the harmonic direction is determined to be normal.

5. The method according to claim 1, characterized in that, After determining the harmonic direction based on the phase difference, the method further includes: The harmonic direction of each AC line is marked accordingly, resulting in multiple marking information; With all the AC lines marked, the power grid harmonic flow direction is constructed based on the multiple marking information.

6. The method according to any one of claims 1 to 5, characterized in that, After determining the harmonic direction, the method further includes: Obtain the harmonic order of the AC line; Obtain the reference current value of the AC line; The degree of harmonic abnormality of the AC line is determined based on the harmonic order and / or current difference, wherein the current difference is the difference between the reference current value and the current value of the harmonic current.

7. A harmonic source tracing device, characterized in that, include: The first acquisition unit is used to acquire multiple first current values ​​and multiple first phase angles, wherein the first current value is the current value of the harmonic current on the AC line collected by the first detection device, and the first phase angle is the phase angle of the harmonic current on the AC line collected by the first detection device. The first current value corresponds one-to-one with the AC line, and the first phase angle corresponds one-to-one with the AC line. The second acquisition unit is used to acquire multiple second current values ​​and multiple second phase angles, wherein the second current value is the current value of the harmonic current on the AC line collected by the second detection device, and the second phase angle is the phase angle of the harmonic current on the AC line collected by the second detection device. The second current value corresponds one-to-one with the AC line, and the second phase angle corresponds one-to-one with the AC line. The first determining unit is configured to determine the harmonic direction based on a plurality of first current values, a plurality of second current values, a plurality of first phase angles, and a plurality of second phase angles; The first determining unit includes a first determining module, a second determining module, and a third determining module. The first determining module is used to determine the largest first current value among a plurality of first current values ​​as a first target current value. The second determining module is used to determine the largest second current value among a plurality of second current values ​​other than the second target current value as a third target current value, wherein the second target current value is one of the second current values, and the AC line corresponding to the second target current value is the same as the AC line corresponding to the first target current value. The third determining module is used to calculate the phase difference between the first target phase angle and the second target phase angle, and determine the harmonic direction based on the phase difference, wherein the first target phase angle is the first phase angle corresponding to the first target current value, and the second target phase angle is the second phase angle corresponding to the third target current value.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the harmonic source tracing method according to any one of claims 1 to 6.

9. A harmonic source tracing system, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including a method for performing the harmonic tracing method according to any one of claims 1 to 6.

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