Power monitoring and early warning method and system

Abstract

The present invention relates to the field of power monitoring technology, and in particular to a power monitoring and early warning method and system. The method of the present invention includes: determining whether the bus should undergo harmonic pollution control by obtaining the harmonic pollution degree of the bus, so as to have a basis for reference; after pollution occurs on the bus, searching for each feeder line connected to the bus to determine the feeder line that should be controlled, which can save procedures and achieve the best control effect. For the feeder line to be controlled, its harmonic pollution parameters are first obtained, and then the harmonic pollution parameters are used to carry out targeted control to reduce or eliminate the pollution of the bus. This implementation path is short, the idea is clear, the procedure is saved, and the control effect is good, which can meet the requirements of harmonic pollution control.

Description

Technical Field

[0001] The present invention relates to the technical field of power monitoring, and in particular to a power monitoring and early warning method and system. Background Art

[0002] Nonlinear loads are those that include a rectifier. In electronic circuits, voltage and current do not have a linear relationship. This relationship constantly changes during the load's operation. Nonlinearity refers to the relationship between the independent variable and the variable, which is not linear but rather a curved or other relationship. Common examples of nonlinear loads include soft starters, switching power supplies, UPSs, inverters, battery chargers, variable-frequency motors, electronic data imaging equipment, controllable lighting, rectifiers, fluorescent lamps, and more.

[0003] From the above examples, we can see that nonlinear loads are widely used in production and life.

[0004] The widespread use of nonlinear loads has led to increasingly severe harmonic pollution in power grids, deteriorating power quality, and placing increasing demands on power system harmonic treatment technologies. Locating harmonic sources in power systems and implementing accurate treatment measures poses a challenge for those skilled in the art.

[0005] Based on this, in order to solve the problem of harmonic pollution in the power grid, it is necessary to develop and design an electric power monitoring and early warning method and system. Summary of the Invention

[0006] The embodiments of the present invention provide a power monitoring and early warning method and system for solving the problem in the prior art that it is difficult to locate the harmonic source and take effective measures.

[0007] In a first aspect, an embodiment of the present invention provides a power monitoring and early warning method, comprising:

[0008] Obtaining a harmonic pollution degree of a bus, wherein the harmonic pollution degree is used to characterize the degree of harmonic pollution;

[0009] If the harmonic pollution degree is greater than the first threshold, a line to be treated is determined, wherein the line to be treated is a feeder line whose harmonic pollution degree is greater than the second threshold, and the feeder line is connected to the busbar;

[0010] Obtaining harmonic pollution parameters of the line to be treated, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution;

[0011] Sending the harmonic pollution parameters and a harmonic pollution exceeding standard warning to the line to be treated;

[0012] Harmonics control is performed on the line to be controlled according to the harmonic pollution parameters.

[0013] In one possible implementation, obtaining the harmonic pollution degree of the bus includes:

[0014] Obtaining the capacity and current waveform of the bus;

[0015] Performing Fourier transform on the current waveform to obtain a fundamental wave and a set of higher harmonics, wherein the set of higher harmonics includes a plurality of higher harmonics of different orders;

[0016] Determining a threshold set according to the capacity, wherein the threshold set includes thresholds for a plurality of different higher-order harmonics;

[0017] Acquire a high-order harmonic ratio set according to the high-order harmonic set and the threshold set, wherein the high-order harmonic ratio set includes high-order harmonic ratios of different high-order harmonics, and the high-order harmonic ratios are used to characterize the harmonic pollution degree of the high-order harmonics;

[0018] The largest high-order harmonic ratio in the high-order harmonic ratio set is selected as the harmonic pollution degree of the bus.

[0019] In one possible implementation, obtaining a high-order harmonic ratio set according to the high-order harmonic set and the threshold set includes:

[0020] The following calculation steps are performed for each of the higher harmonics in the higher harmonic set to obtain a higher harmonic ratio of the corresponding higher harmonic:

[0021] Obtaining a first harmonic ratio and a second harmonic ratio by calculation, respectively, wherein the first harmonic ratio is a ratio of a higher harmonic to a higher harmonic threshold, and the second harmonic ratio is a ratio of a higher harmonic to the fundamental wave;

[0022] A product of the first harmonic ratio and the second harmonic ratio is calculated as a higher harmonic ratio.

[0023] In a possible implementation, the highest harmonic in the high-order harmonic concentration does not exceed the 20th order.

[0024] In one possible implementation, determining the line to be managed includes:

[0025] Obtaining the polluted harmonic order, the number of feeder lines, and the polluted harmonic amplitude, wherein the polluted harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution, and the polluted harmonic amplitude is the amplitude of the higher harmonic with the most serious bus harmonic pollution;

[0026] determining the second threshold value according to the amplitude of the polluting harmonics and the number of the feeder lines;

[0027] For each feeder line, the following calculation steps are performed to obtain the amplitude of the higher harmonics corresponding to the feeder line:

[0028] Obtain the current waveform of the feeder line;

[0029] Performing Fourier transform on the current waveform to obtain the amplitude of a higher harmonic with the same order as the polluting harmonic as the amplitude of the first harmonic of the feeder;

[0030] If the amplitude of the first harmonic of the feeder is greater than the second threshold, the feeder line is determined to be a line to be treated.

[0031] In one possible implementation, the harmonic pollution parameter includes at least one of the following: the pollution harmonic order, the feeder line pollution harmonic amplitude, and the feeder line pollution harmonic phase angle, wherein the pollution harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution; the feeder line pollution harmonic amplitude is the amplitude of the higher harmonic of the feeder line corresponding to the pollution harmonic order; the feeder line pollution harmonic phase angle is the phase angle of the higher harmonic of the feeder line corresponding to the pollution harmonic order.

[0032] In one possible implementation, the harmonic pollution parameters include: the pollution harmonic order, the feeder line pollution harmonic amplitude, and the feeder line pollution harmonic phase angle. The harmonic control of the line to be controlled according to the harmonic pollution parameters includes:

[0033] A control current is generated according to the pollution harmonic order, the feeder line pollution harmonic amplitude and the feeder line pollution harmonic phase angle, wherein the order of the control current is the same as the pollution harmonic order, the amplitude of the control current is the same as the feeder line pollution harmonic amplitude, and the control current is opposite to the feeder line pollution harmonic phase angle.

[0034] In a second aspect, an embodiment of the present invention provides a power detection and early warning system, comprising:

[0035] A bus monitoring device, configured to obtain a harmonic pollution degree of the bus, wherein the harmonic pollution degree is used to characterize the extent of harmonic pollution; if the harmonic pollution degree is greater than a first threshold, determining a line to be treated, wherein the line to be treated is a feeder line having harmonic pollution greater than a second threshold, the feeder line being connected to the bus; obtaining harmonic pollution parameters of the line to be treated, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution; sending the harmonic pollution parameters and a harmonic pollution exceeding standard warning to the line to be treated; and,

[0036] A feeder line control device is used to perform harmonic control on the line to be controlled according to the harmonic pollution parameters.

[0037] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0038] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0039] The embodiment of the present invention discloses an implementation method for an electric power monitoring and early warning method. By obtaining the harmonic pollution degree of the busbar, it determines whether the busbar should be subjected to harmonic pollution control, which provides a basis for reference. After pollution occurs on the busbar, each feeder line connected to the busbar is searched to determine the feeder line that should be treated. This can save procedures and achieve the best treatment effect. For the feeder line to be treated, its harmonic pollution parameters are first obtained. Then, the harmonic pollution parameters are used to carry out targeted treatment to reduce or eliminate the pollution of the busbar. This implementation path is short, the idea is clear, the procedures are saved, and the treatment effect is good, which can meet the requirements of harmonic pollution treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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 any creative labor.

[0041] Figure 1 This is a typical power grid architecture diagram provided by an embodiment of the present invention;

[0042] Figure 2 This is a flow chart of the power monitoring and early warning method provided by an embodiment of the present invention;

[0043] Figure 3 This is a functional block diagram of the power detection and early warning system provided by an embodiment of the present invention;

[0044] Figure 4 This is a functional block diagram of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in alternative embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clear, the following will be described through specific implementation methods in conjunction with the accompanying drawings.

[0047] The following is a detailed description of an embodiment of the present invention. This example is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiment.

[0048] Figure 1 A typical power grid architecture is shown in the figure. In the figure, a busbar 101 is connected to multiple feeders 102, and the feeders 102 are connected to power loads 103 to supply power to the loads 103. When a load 103 in one of the feeders 102 generates harmonics, the entire power grid is polluted by the harmonics.

[0049] Since harmonic pollution caused by any load 103 is reflected in the bus 101, the embodiment of the present invention obtains the current waveform of the bus 101 to determine whether harmonic pollution has occurred and the degree of pollution. When the pollution degree is about to exceed the control capacity of the bus 101, the current waveform of the feeder 102 is obtained and analyzed to determine the feeder line where the harmonic pollution load 103 is located, thereby locating and controlling the pollution source.

[0050] The following is a detailed description with reference to the accompanying drawings.

[0051] Figure 2 This is a flow chart of the power monitoring and early warning method provided by an embodiment of the present invention.

[0052] like Figure 2 As shown, it shows a flow chart of the implementation of the power monitoring and early warning method provided by an embodiment of the present invention, which is detailed as follows:

[0053] In step 201, the harmonic pollution degree of the bus is obtained, wherein the harmonic pollution degree is used to characterize the degree of harmonic pollution.

[0054] In some possible implementations, step 201 includes:

[0055] Obtaining the capacity and current waveform of the busbar;

[0056] Performing Fourier transform on the current waveform to obtain a fundamental wave and a set of higher harmonics, wherein the set of higher harmonics includes a plurality of higher harmonics of different orders;

[0057] Determining a threshold set according to the capacity, wherein the threshold set includes thresholds for a plurality of different higher-order harmonics;

[0058] Acquire a high-order harmonic ratio set according to the high-order harmonic set and the threshold set, wherein the high-order harmonic ratio set includes high-order harmonic ratios of different high-order harmonics, and the high-order harmonic ratios are used to characterize the harmonic pollution degree of the high-order harmonics;

[0059] The largest high-order harmonic ratio in the high-order harmonic ratio set is selected as the harmonic pollution degree of the bus.

[0060] In some possible implementations, obtaining a high-order harmonic ratio set according to the high-order harmonic set and the threshold set includes:

[0061] The following calculation steps are performed for each of the higher harmonics in the higher harmonic set to obtain a higher harmonic ratio of the corresponding higher harmonic:

[0062] Obtaining a first harmonic ratio and a second harmonic ratio by calculation, respectively, wherein the first harmonic ratio is a ratio of a higher harmonic to a higher harmonic threshold, and the second harmonic ratio is a ratio of a higher harmonic to the fundamental wave;

[0063] A product of the first harmonic ratio and the second harmonic ratio is calculated as a higher harmonic ratio.

[0064] In some possible implementations, the highest harmonic in the high-order harmonic concentration does not exceed the 20th order.

[0065] For example, the current waveform can be obtained through the current transformer of bus 101. Some bus 101 line systems are equipped with an oscilloscope that can record the waveform of the bus 101 current. These are all ways to obtain the bus 101 circuit waveform.

[0066] After Fourier transform of the current waveform, there will be a fundamental wave and usually higher harmonics. Different thresholds are set according to the number of higher harmonics, and the threshold is also related to the capacity of the bus.

[0067] In order to reduce unnecessary calculations, the number of harmonics actually occurring in the bus is taken into consideration, and the first 20 harmonics are usually obtained from the values ​​of higher harmonics.

[0068] Since the harmonic damage is related not only to the degree of harmonic occurrence but also to the harmonic order, the higher the order, the greater the damage. Therefore, when setting the threshold, the higher the harmonic order, the lower the threshold.

[0069] The pollution level in the embodiment of the present invention is indicated by the higher harmonic ratio. The higher harmonic ratio is the ratio of the higher harmonics to the higher harmonic threshold, multiplied by the second harmonic ratio to obtain the ratio of the higher harmonics to the fundamental wave. Therefore, the higher harmonic ratio (i.e., harmonic pollution level) can simultaneously reflect the ratio of the higher harmonics to the fundamental wave and the ratio of the higher harmonics to the threshold, making the pollution level more representative.

[0070] In step 202, if the harmonic pollution level is greater than a first threshold, a line to be controlled is determined, wherein the line to be controlled is a feeder line whose harmonic pollution level is greater than a second threshold, and the feeder line is connected to the busbar.

[0071] In some possible implementations, determining the line to be managed includes:

[0072] Obtaining the polluted harmonic order, the number of feeder lines, and the polluted harmonic amplitude, wherein the polluted harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution, and the polluted harmonic amplitude is the amplitude of the higher harmonic with the most serious bus harmonic pollution;

[0073] determining the second threshold value according to the amplitude of the polluting harmonics and the number of the feeder lines;

[0074] For each feeder line, the following calculation steps are performed to obtain the amplitude of the higher harmonics corresponding to the feeder line:

[0075] Obtain the current waveform of the feeder line;

[0076] Performing Fourier transform on the current waveform to obtain the amplitude of a higher harmonic with the same order as the polluting harmonic as the amplitude of the first harmonic of the feeder;

[0077] If the amplitude of the first harmonic of the feeder is greater than the second threshold, the feeder line is determined to be a line to be treated.

[0078] For example, after determining that the busbar has generated a certain degree of harmonic pollution, it is necessary to perform harmonic analysis on each feeder line to determine the feeder line that needs to be treated.

[0079] In order to treat harmonic pollution in a targeted manner, first, the harmonic order and amplitude of the busbar pollution harmonics are obtained.

[0080] As mentioned above, in some solutions of step 201, the high-order harmonics that mainly affect the bus harmonic pollution have been obtained through Fourier transform. Here, we can directly use the amplitude and order of the high-order harmonics.

[0081] Correspondingly, after Fourier transforming the current waveform of the feeder line, multiple high-order harmonics are generated. Among them, we only focus on the same harmonics as the high-order harmonics that have a major impact on the bus (it will be explained later that the selection here is for governance needs).

[0082] When selecting the harmonic pollution threshold of the feeder line, the polluting harmonic amplitude and the number of feeder lines should be considered simultaneously. For example, in one embodiment, the threshold is obtained by dividing the harmonic amplitude by the number of feeder lines. Note that the enumeration here is for ease of understanding, and those skilled in the art should understand that the above enumeration does not constitute a limitation.

[0083] After obtaining the target higher harmonics of the feeder line (the higher harmonics are of the same order as the harmonics that have a major impact on the bus), the amplitude of the higher harmonics is extracted. When the amplitude exceeds the threshold, it can be determined that the feeder line corresponding to the waveform is the line to be managed.

[0084] In step 203, the harmonic pollution parameters of the line to be treated are obtained, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution.

[0085] In step 204, the harmonic pollution parameters and a harmonic pollution exceeding standard warning are sent to the line to be treated.

[0086] In some possible implementations, the harmonic pollution parameters include at least one of the following: the pollution harmonic order, the feeder line pollution harmonic amplitude, and the feeder line pollution harmonic phase angle, wherein the pollution harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution; the feeder line pollution harmonic amplitude is the amplitude of the higher harmonic of the feeder line corresponding to the pollution harmonic order; the feeder line pollution harmonic phase angle is the phase angle of the higher harmonic of the feeder line corresponding to the pollution harmonic order.

[0087] For example, as described in the aforementioned step 202, after obtaining the target higher-order harmonics, we can further obtain the amplitude of the feeder line pollution harmonics and the phase angle of the feeder line pollution harmonics, which are crucial for harmonic control.

[0088] For example, in one possible implementation method, the frequency and amplitude of harmonic pollution can be targeted for treatment, compensation or elimination.

[0089] In step 205, harmonic control is performed on the line to be controlled according to the harmonic pollution parameters.

[0090] In some possible implementations, step 205 includes:

[0091] A control current is generated according to the pollution harmonic order, the feeder line pollution harmonic amplitude and the feeder line pollution harmonic phase angle, and the control current is used to offset the harmonic pollution of higher harmonics of the harmonic order.

[0092] In some possible implementations, the order of the control current is the same as the order of the pollution harmonics, the amplitude of the control current is the same as the amplitude of the feeder line pollution harmonics, and the phase angles of the control current and the feeder line pollution harmonics are opposite.

[0093] For example, one possible governance method is active governance. The basic idea of ​​active governance is to offset the pollution source by generating a waveform targeting harmonic pollution.

[0094] Therefore, one of the control methods is to generate a control current, which has the same order and amplitude as the pollution harmonics, but the opposite current direction (that is, the opposite phase angle).

[0095] In practical applications, this current can be generated by distributed power sources, such as wind power generation and solar power generation. By controlling the grid-connected current, harmonic pollution can be offset.

[0096] There is also an energy storage active control method. After the energy storage mechanism absorbs electrical energy from the power grid, it stores it in an energy storage device, such as a power capacitor, and controls the current discharged from the capacitor to the power grid to achieve the purpose of offsetting harmonic pollution.

[0097] The power monitoring and early warning method of the present invention obtains the harmonic pollution degree of the busbar to determine whether the busbar should undergo harmonic pollution control, providing a basis for reference. After pollution occurs on the busbar, each feeder line connected to the busbar is searched to determine the feeder line that should undergo control. This method can save procedures and achieve the best control effect. For the feeder line to be controlled, its harmonic pollution parameters are first obtained. Then, the harmonic pollution parameters are used to carry out targeted control to reduce or eliminate the busbar pollution. This method has a short implementation path, clear ideas, and saves procedures. It also has good control effects and can meet the requirements of harmonic pollution control.

[0098] It should be understood that the size of the serial numbers of each step in the above embodiment 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 embodiment of the present invention.

[0099] The following is an embodiment of the device of the present invention. For details not described in detail, please refer to the corresponding method embodiment described above.

[0100] Figure 3 This is a functional block diagram of the power detection and early warning system provided by the embodiment of the present invention, referring to Figure 3 , the harmonic early warning device 3 includes: a bus monitoring device 301 and a feeder line control device 302;

[0101] The bus monitoring device 301 is configured to obtain a harmonic pollution degree of the bus, wherein the harmonic pollution degree is used to characterize the extent of harmonic pollution; if the harmonic pollution degree is greater than a first threshold, determine a line to be treated, wherein the line to be treated is a feeder line whose harmonic pollution is greater than a second threshold, and the feeder line is connected to the bus; obtain harmonic pollution parameters of the line to be treated, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution; and send the harmonic pollution parameters and a harmonic pollution exceeding standard warning to the line to be treated;

[0102] The feeder line control device 302 is used to perform harmonic control on the line to be controlled according to the harmonic pollution parameters.

[0103] Figure 4 This is a functional block diagram of a terminal provided by an embodiment of the present invention. Figure 4 As shown, the terminal 4 of this embodiment includes: a processor 400, a memory 401, and a computer program 402 stored in the memory 401 and executable on the processor 400. When the processor 400 executes the computer program 402, the steps of the above-mentioned power monitoring and early warning method and the power monitoring and early warning method embodiment are implemented, for example Figure 2 Steps 201 to 205 are shown.

[0104] Illustratively, the computer program 402 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 401 and executed by the processor 400 to implement the present invention.

[0105] The terminal 4 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal 4 may include, but is not limited to, a processor 400 and a memory 401. Those skilled in the art will understand that Figure 4 It is only an example of terminal 4 and does not constitute a limitation on terminal 4. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0106] The processor 400 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.

[0107] The memory 401 may be an internal storage unit of the terminal 4, such as a hard disk or memory of the terminal 4. The memory 401 may also be an external storage device of the terminal 4, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 4. Furthermore, the memory 401 may include both an internal storage unit of the terminal 4 and an external storage device. The memory 401 is used to store the computer program and other programs and data required by the terminal. The memory 401 may also be used to temporarily store data that has been output or is about to be output.

[0108] Those skilled in the art can clearly understand that, for the convenience and brevity 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 functions can be distributed and 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 one processing unit, or each unit can exist physically alone, 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, and will not be repeated here.

[0109] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0110] 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. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0111] In the embodiments provided herein, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components being combined or integrated into another system, or some features being ignored or not implemented. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interface, or the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0112] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of this embodiment.

[0113] In addition, the functional units in various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0114] 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 embodiment 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 power monitoring and early warning methods and harmonic early warning 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, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0115] 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, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These 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 scope of protection of the present invention.

Claims

1. A power monitoring and early warning method, characterized in that: include: Obtaining a harmonic pollution degree of a bus, wherein the harmonic pollution degree is used to characterize the degree of harmonic pollution; If the harmonic pollution degree is greater than the first threshold, a line to be treated is determined, wherein the line to be treated is a feeder line whose harmonic pollution degree is greater than the second threshold, and the feeder line is connected to the busbar; Obtaining harmonic pollution parameters of the line to be treated, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution; Sending the harmonic pollution parameters and a harmonic pollution exceeding standard warning to the line to be treated; Performing harmonic control on the line to be controlled according to the harmonic pollution parameters; The obtaining of the harmonic pollution degree of the bus includes: Obtaining the capacity and current waveform of the busbar; Performing Fourier transform on the current waveform to obtain a fundamental wave and a set of higher harmonics, wherein the set of higher harmonics includes a plurality of higher harmonics of different orders; Determining a threshold set according to the capacity, wherein the threshold set includes thresholds for a plurality of different higher-order harmonics; Acquire a high-order harmonic ratio set according to the high-order harmonic set and the threshold set, wherein the high-order harmonic ratio set includes high-order harmonic ratios of different high-order harmonics, and the high-order harmonic ratios are used to characterize the harmonic pollution degree of the high-order harmonics; Selecting the largest high-order harmonic ratio in the high-order harmonic ratio set as the harmonic pollution degree of the bus; The acquiring a high-order harmonic ratio set according to the high-order harmonic set and the threshold set includes: The following calculation steps are performed for each of the higher harmonics in the higher harmonic set to obtain a higher harmonic ratio of the corresponding higher harmonic: Obtaining a first harmonic ratio and a second harmonic ratio by calculation, respectively, wherein the first harmonic ratio is a ratio of a higher harmonic to a higher harmonic threshold, and the second harmonic ratio is a ratio of a higher harmonic to the fundamental wave; calculating a product of the first harmonic ratio and the second harmonic ratio as a higher harmonic ratio; Determining the line to be managed includes: Obtaining the polluted harmonic order, the number of feeder lines, and the polluted harmonic amplitude, wherein the polluted harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution, and the polluted harmonic amplitude is the amplitude of the higher harmonic with the most serious bus harmonic pollution; determining the second threshold value according to the amplitude of the polluting harmonics and the number of the feeder lines; For each feeder line, the following calculation steps are performed to obtain the amplitude of the higher harmonics corresponding to the feeder line: Obtain the current waveform of the feeder line; Performing Fourier transform on the current waveform to obtain the amplitude of a higher harmonic with the same order as the polluting harmonic as the amplitude of the first harmonic of the feeder; If the amplitude of the first harmonic of the feeder is greater than the second threshold, the feeder line is determined to be a line to be treated.

2. The power monitoring and early warning method according to claim 1, characterized in that: The highest harmonic in the high-order harmonic concentration does not exceed the 20th order.

3. The power monitoring and early warning method according to any one of claims 1-2, characterized in that: The harmonic pollution parameters include at least one of the following: the pollution harmonic order, the feeder line pollution harmonic amplitude and the feeder line pollution harmonic phase angle, wherein the pollution harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution; the feeder line pollution harmonic amplitude is the amplitude of the higher harmonic of the feeder line corresponding to the pollution harmonic order; the feeder line pollution harmonic phase angle is the phase angle of the higher harmonic of the feeder line corresponding to the pollution harmonic order.

4. The power monitoring and early warning method according to claim 3, characterized in that: The harmonic pollution parameters include: the pollution harmonic order, the feeder line pollution harmonic amplitude, and the feeder line pollution harmonic phase angle. The harmonic control of the line to be controlled according to the harmonic pollution parameters includes: A control current is generated according to the pollution harmonic order, the feeder line pollution harmonic amplitude and the feeder line pollution harmonic phase angle, and the control current is used to offset the harmonic pollution of higher harmonics of the harmonic order.

5. The electric power monitoring and early warning method according to claim 4, characterized in that: The order of the control current is the same as the order of the pollution harmonics, the amplitude of the control current is the same as the amplitude of the feeder line pollution harmonics, and the phase angles of the control current and the feeder line pollution harmonics are opposite.

6. An electric power monitoring and early warning system, characterized in that: include: A bus monitoring device, configured to obtain a harmonic pollution degree of the bus, wherein the harmonic pollution degree is used to characterize the extent of harmonic pollution; if the harmonic pollution degree is greater than a first threshold, determining a line to be treated, wherein the line to be treated is a feeder line having harmonic pollution greater than a second threshold, the feeder line being connected to the bus; obtaining harmonic pollution parameters of the line to be treated, wherein the harmonic pollution parameters are used to characterize various indicators of harmonic pollution; sending the harmonic pollution parameters and a harmonic pollution exceeding standard warning to the line to be treated; and, A feeder line control device, configured to perform harmonic control on the line to be controlled according to the harmonic pollution parameters; The obtaining of the harmonic pollution degree of the bus includes: Obtaining the capacity and current waveform of the busbar; Performing Fourier transform on the current waveform to obtain a fundamental wave and a set of higher harmonics, wherein the set of higher harmonics includes a plurality of higher harmonics of different orders; Determining a threshold set according to the capacity, wherein the threshold set includes thresholds for a plurality of different higher-order harmonics; Acquire a high-order harmonic ratio set according to the high-order harmonic set and the threshold set, wherein the high-order harmonic ratio set includes high-order harmonic ratios of different high-order harmonics, and the high-order harmonic ratios are used to characterize the harmonic pollution degree of the high-order harmonics; Selecting the largest high-order harmonic ratio in the high-order harmonic ratio set as the harmonic pollution degree of the bus; The acquiring a high-order harmonic ratio set according to the high-order harmonic set and the threshold set includes: The following calculation steps are performed for each of the higher harmonics in the higher harmonic set to obtain a higher harmonic ratio of the corresponding higher harmonic: Obtaining a first harmonic ratio and a second harmonic ratio by calculation, respectively, wherein the first harmonic ratio is a ratio of a higher harmonic to a higher harmonic threshold, and the second harmonic ratio is a ratio of a higher harmonic to the fundamental wave; calculating a product of the first harmonic ratio and the second harmonic ratio as a higher harmonic ratio; Determining the line to be managed includes: Obtaining the polluted harmonic order, the number of feeder lines, and the polluted harmonic amplitude, wherein the polluted harmonic order is the order of the higher harmonic with the most serious bus harmonic pollution, and the polluted harmonic amplitude is the amplitude of the higher harmonic with the most serious bus harmonic pollution; determining the second threshold value according to the amplitude of the polluting harmonics and the number of the feeder lines; For each feeder line, the following calculation steps are performed to obtain the amplitude of the higher harmonics corresponding to the feeder line: Obtain the current waveform of the feeder line; Performing Fourier transform on the current waveform to obtain the amplitude of a higher harmonic with the same order as the polluting harmonic as the amplitude of the first harmonic of the feeder; If the amplitude of the first harmonic of the feeder is greater than the second threshold, the feeder line is determined to be a line to be treated.

7. 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 according to any one of claims 1 to 5 are implemented.

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