阅读说明：本技术 一种输电网节点的谐波超标预警方法、装置、设备及介质 (Harmonic superstandard early warning method, device, equipment and medium for power transmission network nodes ) 是由 周挺辉 黄冠标 甄鸿越 赵利刚 王长香 翟鹤峰 徐原 吴小珊 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种输电网节点的谐波超标预警方法、装置、设备及介质,在网络条件发生变化后,通过对比计算得到的各个节点处的最大谐波电压与预设的电压阈值的大小,若该节点处的最大谐波电压大于预设的电压阈值,则生成谐波超标预警信息。采用本发明实施例,采用实测数据加公式推导分析的方法,将分布产生的谐波源等效至所研究范围内的多个节点,能够准确的分析输电网各节点的谐波是否超标,有效避免输电网的各节点设备因谐波超标而造成的损坏,减少了电力损失。(The invention discloses a harmonic overproof early warning method, a harmonic overproof early warning device, harmonic overproof early warning equipment and a harmonic overproof early warning medium for nodes of a power transmission network. By adopting the embodiment of the invention, the method of actual measurement data and formula derivation analysis is adopted, the distributed generated harmonic source is equivalent to a plurality of nodes in the researched range, whether the harmonic of each node of the power transmission network exceeds the standard can be accurately analyzed, the damage of each node device of the power transmission network caused by the harmonic exceeding the standard is effectively avoided, and the power loss is reduced.)

1. A harmonic superstandard early warning method for nodes of a power transmission network is characterized by comprising the following steps:

s1, acquiring injected harmonic current at each node before network condition changes;

s2, forming a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes;

s3, calculating harmonic voltages at the nodes after the network condition changes according to the injected harmonic currents at the nodes before the network condition changes and the node admittance matrixes at the nodes after the network condition changes;

s4, repeatedly executing the steps S1-S3 according to preset conditions to obtain the maximum harmonic voltage at each node after the network conditions change;

and S5, for each node, if the maximum harmonic voltage at the node after the network condition changes is larger than a preset voltage threshold, generating harmonic over-standard early warning information.

2. The harmonic overproof warning method of the power transmission network node according to claim 1, wherein the step S1 specifically comprises:

forming a node admittance matrix before the network change according to a harmonic model of each element of the power transmission network before the network change;

obtaining the amplitude and phase angle of harmonic voltage at each node before network change;

calculating the harmonic voltage at each node before the network change according to the amplitude and the phase angle of the harmonic voltage at each node before the network change;

and calculating the injection harmonic current at each node before the network change according to the harmonic voltage at each node before the network change and the node admittance matrix before the network change.

3. The harmonic overproof warning method of the transmission network node according to claim 2, wherein the change of the network condition in the step S2 mainly comprises the input or the exit of any one or more circuit components.

4. The harmonic overproof warning method of the transmission grid node according to claim 3, wherein the calculation formula of the step S3 is as follows:

wherein the content of the first and second substances,for the injected harmonic current, Y, at each node before the change in the network conditions_n，newA node admittance matrix for each node after the network condition changes,the harmonic voltages at the nodes after the network condition changes.

5. The harmonic overproof warning method of the power transmission network node according to claim 4, wherein the step S4 specifically comprises the steps of:

repeating the steps S1-S3 according to the preset times t to obtain t harmonic voltages at each node;

obtaining the maximum harmonic voltage at each node according to the t harmonic voltages at each node;

wherein, in each execution, the phase angle of the harmonic voltage at each node before the network change is taken as a different value in the range of 0 to 360 degrees.

6. The harmonic overproof warning method of the power transmission network node according to claim 2, wherein the obtaining of the amplitude and phase angle of the harmonic voltage at each node before the network change is specifically:

measuring and recording the voltage at each node of the power transmission network by using a harmonic detection instrument, and obtaining the voltage amplitude under each subharmonic by adopting Fourier transform;

the phase angle of the harmonic voltage is a random number in the range of 0 to 360 degrees.

7. The harmonic overproof warning method of the power transmission network node according to claim 2, wherein the harmonic voltage at each node before the network change is calculated according to the amplitude and the phase angle of the harmonic voltage at each node before the network change, specifically:

wherein the content of the first and second substances,the harmonic voltages at the various nodes before the network conditions change,for the harmonic voltage, U, at the kth node before the network change_k∠∝_kIs composed ofIn polar coordinate form, U_kIs the amplitude and is specific to_kAnd m is the total number of nodes.

8. The utility model provides a harmonic that transmission network node exceeds standard early warning device which characterized in that includes:

the harmonic current acquisition module is used for acquiring the injected harmonic current at each node before the network condition changes;

the admittance matrix forming module is used for forming a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes;

the harmonic voltage calculation module is used for calculating the harmonic voltage at each node after the network condition changes according to the injected harmonic current at each node before the network condition changes and the node admittance matrix at each node after the network condition changes;

a maximum harmonic voltage calculation module, configured to repeatedly execute steps S1-S3 according to a preset condition, to obtain a maximum harmonic voltage at each node after the network condition changes;

and the early warning information generation module is used for generating the harmonic exceeding early warning information for each node if the maximum harmonic voltage at the node after the network condition changes is greater than a preset voltage threshold.

9. A terminal device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, the processor when executing the computer program implementing a harmonic overproof warning method for a power transmission network node according to any of claims 1 to 7.

10. A computer-readable storage medium, comprising a stored computer program, wherein the computer program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform a harmonic excess warning method of a power transmission network node according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of electric power, in particular to a harmonic overproof early warning method, a harmonic overproof early warning device, harmonic overproof early warning equipment and a harmonic overproof early warning medium for nodes of a power transmission network.

Background

Harmonic is a kind of electric power pollution, and the harm to the power network is very serious, and the governance of harmonic generally follows the principle of who pollutes, who governs.

In order to accurately grasp the influence caused by the harmonic wave, in the traditional method, a harmonic wave trend calculation method is generally adopted for research, but the source of the adopted harmonic wave source is distributed, the harmonic wave source is very wide, almost any equipment can generate the harmonic wave, and for the equipment of different manufacturers, the harmonic wave size is different even under the same voltage level, the derivation and the actual difference are larger based on a unified formula, and whether the harmonic wave exceeds the standard or not and the influence caused by the harmonic wave cannot be accurately grasped.

Disclosure of Invention

The embodiment of the invention provides a harmonic overproof early warning method, a harmonic overproof early warning device, harmonic overproof equipment and a harmonic overproof medium for nodes of a power transmission network.

In order to achieve the above object, an embodiment of the present invention provides a method for warning excessive harmonic of a power transmission network node, including the following steps:

s1, acquiring injected harmonic current at each node before network condition changes;

s2, forming a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes;

s3, calculating harmonic voltages at the nodes after the network condition changes according to the injected harmonic currents at the nodes before the network condition changes and the node admittance matrixes at the nodes after the network condition changes;

s4, repeatedly executing the steps S1-S3 according to preset conditions to obtain the maximum harmonic voltage at each node after the network conditions change;

and S5, for each node, if the maximum harmonic voltage at the node after the network condition changes is larger than a preset voltage threshold, generating harmonic over-standard early warning information.

Further, the step S1 is specifically:

forming a node admittance matrix before the network change according to a harmonic model of each element of the power transmission network before the network change;

obtaining the amplitude and phase angle of harmonic voltage at each node before network change;

calculating the harmonic voltage at each node before the network change according to the amplitude and the phase angle of the harmonic voltage at each node before the network change;

and calculating the injection harmonic current at each node before the network change according to the harmonic voltage at each node before the network change and the node admittance matrix before the network change.

Further, the step S2, where the change in the network condition mainly includes the step of entering or exiting any one or more circuit components.

Further, the calculation formula of step S3 is:

wherein the content of the first and second substances,for the injected harmonic current, Y, at each node before the change in the network conditions_n,newA node admittance matrix for each node after the network condition changes,the harmonic voltages at the nodes after the network condition changes.

Further, the step S4 specifically includes:

repeating the steps S1-S3 according to the preset times t to obtain t harmonic voltages at each node;

obtaining the maximum harmonic voltage at each node according to the t harmonic voltages at each node;

wherein, in each execution, the phase angle of the harmonic voltage at each node before the network change is taken as a different value in the range of 0 to 360 degrees.

Further, the obtaining of the amplitude and the phase angle of the harmonic voltage at each node before the network change specifically includes:

measuring and recording the voltage at each node of the power transmission network by using a harmonic detection instrument, and obtaining the voltage amplitude under each subharmonic by adopting Fourier transform;

the phase angle of the harmonic voltage is a random number in the range of 0 to 360 degrees.

Further, the calculating the harmonic voltage at each node before the network change according to the amplitude and the phase angle of the harmonic voltage at each node before the network change includes:

wherein the content of the first and second substances,the harmonic voltages at the various nodes before the network conditions change,for the harmonic voltage, U, at the kth node before the network change_k∠∝_kIs composed ofIn polar coordinate form, U_kIs the amplitude and is specific to_kAnd m is the total number of nodes.

Another embodiment of the present invention correspondingly provides a device for warning excessive harmonic in a node of a power transmission network, including:

the harmonic current acquisition module is used for acquiring the injected harmonic current at each node before the network condition changes;

the admittance matrix forming module is used for forming a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes;

the harmonic voltage calculation module is used for calculating the harmonic voltage at each node after the network condition changes according to the injected harmonic current at each node before the network condition changes and the node admittance matrix at each node after the network condition changes;

a maximum harmonic voltage calculation module, configured to repeatedly execute steps S1-S3 according to a preset condition, to obtain a maximum harmonic voltage at each node after the network condition changes;

and the early warning information generation module is used for generating the harmonic exceeding early warning information for each node if the maximum harmonic voltage at the node after the network condition changes is greater than a preset voltage threshold.

Another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the harmonic superstandard warning method for a power transmission network node according to the above embodiment of the present invention is implemented.

Another embodiment of the present invention provides a storage medium, where the computer-readable storage medium includes a stored computer program, where when the computer program runs, a device in which the computer-readable storage medium is located is controlled to execute the method for warning harmonic superstandard of a power transmission network node according to the above-described embodiment of the present invention.

Compared with the prior art, the harmonic overproof early warning method, the harmonic overproof early warning device, the harmonic overproof early warning equipment and the harmonic overproof early warning medium for the nodes of the power transmission network disclosed by the embodiment of the invention have the advantages that after network conditions change, the maximum harmonic voltage at each node is obtained by comparing the maximum harmonic voltage with the preset voltage threshold value, and if the maximum harmonic voltage at the node is greater than the preset voltage threshold value, the harmonic overproof early warning information is generated. By adopting the embodiment of the invention, the distributed generated harmonic source is equivalent to a plurality of nodes in the researched range by adopting the method of actually measured data and formula derivation analysis, whether the harmonic of each node of the power transmission network exceeds the standard or not can be accurately analyzed, the damage of each node device of the power transmission network caused by the harmonic exceeding the standard is effectively avoided, and the power loss is reduced.

Drawings

Fig. 1 is a schematic flow chart of a harmonic superstandard early warning method for a power transmission network node according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a harmonic superstandard early warning device for a power transmission network node according to an embodiment of the present invention;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a schematic flow chart of a harmonic overproof warning method for a power transmission network node according to an embodiment of the present invention is shown, where the method includes steps S1 to S5:

and S1, acquiring the injected harmonic current at each node before the network condition changes.

And S2, forming a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes.

And S3, calculating the harmonic voltage at each node after the network condition changes according to the injected harmonic current at each node before the network condition changes and the node admittance matrix at each node after the network condition changes.

S4, repeating the steps S1-S3 according to the preset conditions, and obtaining the maximum harmonic voltage at each node after the network conditions change.

And S5, for each node, if the maximum harmonic voltage at the node after the network condition changes is larger than a preset voltage threshold, generating harmonic over-standard early warning information.

Further, the step S1 is specifically:

and forming a node admittance matrix before the network change according to the harmonic model of each element of the power transmission network before the network change.

And obtaining the amplitude and the phase angle of the harmonic voltage at each node before the network changes.

And calculating the harmonic voltage at each node before the network change according to the amplitude and the phase angle of the harmonic voltage at each node before the network change.

And calculating the injection harmonic current at each node before the network change according to the harmonic voltage at each node before the network change and the node admittance matrix before the network change.

Further, the node admittance matrix Y before the network change_nComprises the following steps:

wherein, Y_nIs node admittance moment at nth harmonicArray, Y_kmIs the inverse of the common transadmittance between the k and m nodes, Y_kkIs the self-admittance of the kth node, and m is the total number of the nodes.

The node admittance matrix Y_nThe harmonic model of each element adopts a calculation method universal for a power system.

Further, the obtaining of the amplitude and the phase angle of the harmonic voltage at each node before the network change specifically includes:

and simultaneously measuring and recording the voltage at each node of the power transmission network by using a harmonic detection instrument, and obtaining the voltage amplitude under each subharmonic by adopting Fourier transform.

The harmonic detection instrument can be a harmonic detector.

The simultaneous measurement and recording of the voltages at the various nodes of the grid is simultaneous with time contained within an error range of 10s and 10 s.

The phase angle of the harmonic voltage is a random number in the range of 0 to 360 degrees.

Further, the calculating the harmonic voltage at each node before the network change according to the amplitude and the phase angle of the harmonic voltage at each node before the network change includes:

wherein the content of the first and second substances,the harmonic voltages at the various nodes before the network conditions change,for the harmonic voltage, U, at the kth node before the network change_k∠∝_kIs composed ofIn polar coordinate form, U_kIs the amplitude and is specific to_kAnd m is the total number of nodes.

Further, the calculating, according to the harmonic voltage at each node before the network change and the node admittance matrix before the network change, the injected harmonic current at each node before the network change is specifically:

for the nth harmonic power flow, the harmonic power flow equation is as follows:namely:

wherein the content of the first and second substances,for the injected harmonic current at each node at the nth harmonic,for the injected harmonic current at the kth node,the harmonic voltages at the respective nodes at the nth harmonic,is the harmonic voltage at the kth node.

Further, the step S2, where the change in the network condition mainly includes the step of entering or exiting any one or more circuit components.

Specifically, the circuit components include, but are not limited to, transmission lines, transformers, capacitors, reactors, generators, and loads.

The node admittance matrix Y of each node after the network condition changes_n,newIs calculated byThe typical part of the general calculation method of the power system operates as follows.

For example, for a device having a capacitance, reactor, etc. input at the kth node, the admittance for that device is Y_kAnd then:

and for circuit components that are put in before node k and node m, then:

if the actual operation is quit and not input, the correction amount Y is_nBoth require the addition of a negative sign.

Further, the calculation formula of step S3 is:

wherein the content of the first and second substances,for the injected harmonic current, Y, at each node before the change in the network conditions_n,newA node admittance matrix for each node after the network condition changes,the harmonic voltages at the nodes after the network condition changes.

Specifically, the harmonic voltages at the nodes after the network condition changesThe expression of (a) is:

thenThe solving process of (2) is as follows:

further, the step S4 specifically includes:

repeating the steps S1-S3 according to the preset times t to obtain t harmonic voltages at each node;

obtaining the maximum harmonic voltage at each node according to the t harmonic voltages at each node;

wherein, in each execution, the phase angle of the harmonic voltage at each node before the network change is taken as a different value in the range of 0 to 360 degrees.

Specifically, the preset number t may be 1000, and in an actual application process, the value of the preset number t may be adjusted according to an actual condition of the power system.

Further, the step S5 is specifically:

for each node, judging whether the maximum harmonic voltage at the node after the network condition is changed is larger than a preset voltage threshold, wherein the preset voltage threshold refers to a typical range of 1.0% -1.5% of an odd harmonic limit value according to DL/T5426-containing 2009 +/-800 kV high-voltage direct-current transmission system complete design rule and DL/T5223-containing 2005 high-voltage direct-current converter station design technical regulation, the maximum is not more than 1.5%, the limit value of an even harmonic is 0.5%, and the even harmonic generally does not exceed the standard.

For each node, if the maximum harmonic voltage of the node after the network condition changes is larger than a preset voltage threshold, indicating that the harmonic of the node exceeds the standard, generating harmonic exceeding early warning information; and if the maximum harmonic voltage at the node after the network condition is changed is smaller than a preset voltage threshold, indicating that the harmonic of the node does not exceed the standard, not generating the harmonic exceeding early warning information.

For example: if the scheme of adding the filter is adopted, the method is equivalent to accessing a ground branch at a certain node, and according to the harmonic overproof early warning method of the power transmission network node, the admittance matrix at the node under the state of the filter, namely the admittance matrix at the node after the network state is changed, is calculated, so that the maximum harmonic voltage at the node under the new state after the network state is changed is obtained, and the effect of the filter is inspected. If the maximum filtering voltage exceeds the standard, other measures such as changing filter parameters or building a new line can be adopted, and the effect verification can be carried out by adopting the harmonic overproof early warning method of the power transmission network node after the measures are carried out.

Compared with the prior art, the harmonic overproof early warning method for the power transmission network nodes disclosed by the embodiment of the invention has the advantages that after network conditions change, the maximum harmonic voltage at each node is obtained by comparing calculation with the preset voltage threshold, and if the maximum harmonic voltage at the node is larger than the preset voltage threshold, harmonic overproof early warning information is generated. By adopting the embodiment of the invention, the distributed generated harmonic source is equivalent to a plurality of nodes in the researched range by adopting the method of actually measured data and formula derivation analysis, whether the harmonic of each node of the power transmission network exceeds the standard or not can be accurately analyzed, the damage of each node device of the power transmission network caused by the harmonic exceeding the standard is effectively avoided, and the power loss is reduced.

Referring to fig. 2, a schematic structural diagram of a harmonic superstandard warning apparatus for a power transmission network node according to an embodiment of the present invention includes:

an admittance matrix forming module 11, configured to form a node admittance matrix at each node after the network condition changes according to the harmonic model at each node of the power transmission network after the network condition changes;

a harmonic current obtaining module 12, configured to obtain an injected harmonic current at each node before a network condition changes;

a harmonic voltage calculation module 13, configured to calculate a harmonic voltage at each node after the network condition changes according to the injected harmonic current at each node before the network condition changes and the node admittance matrix at each node after the network condition changes;

a maximum harmonic voltage calculation module 14, configured to repeatedly execute steps S1 to S3 according to a preset condition, to obtain a maximum harmonic voltage at each node after the network condition changes;

and the warning information generating module 15 is configured to, for each node, generate the warning information that the harmonic exceeds the standard if the maximum harmonic voltage at the node after the network condition changes is greater than a preset voltage threshold.

Compared with the prior art, the harmonic overproof early warning device for the nodes of the power transmission network disclosed by the embodiment of the invention has the advantages that after network conditions change, the maximum harmonic voltage at each node is obtained by comparing calculation with the preset voltage threshold, and if the maximum harmonic voltage at the node is greater than the preset voltage threshold, harmonic overproof early warning information is generated. By adopting the embodiment of the invention, the distributed generated harmonic source is equivalent to a plurality of nodes in the researched range by adopting the method of actually measured data and formula derivation analysis, whether the harmonic of each node of the power transmission network exceeds the standard or not can be accurately analyzed, the damage of each node device of the power transmission network caused by the harmonic exceeding the standard is effectively avoided, and the power loss is reduced.

Another embodiment of the present invention provides a terminal device, where the terminal device includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. And when the processor executes the computer program, the steps in the above-mentioned harmonic overproof early warning method embodiment of each transmission network node are realized. Alternatively, the processor implements the functions of the modules in the above device embodiments when executing the computer program.

Illustratively, the computer program may be partitioned into one or more modules that are stored in the memory and executed by the processor to implement the invention. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which are used for describing the execution process of the computer program in the terminal device.

The terminal device can be a desktop computer, a notebook, a palm computer, a cloud server and other computing devices. The terminal device may include, but is not limited to, a processor, a memory. It will be appreciated by those skilled in the art that the schematic diagram is merely an example of a terminal device and does not constitute a limitation of a terminal device, and may include more or less components than those shown, or combine certain components, or different components, for example, the terminal device may also include input output devices, network access devices, buses, etc.

The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, or the like. The general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like, which is the control center of the terminal device and connects the various parts of the whole terminal device using various interfaces and lines.

The memory may be used for storing the computer programs and/or modules, and the processor may implement various functions of the terminal device by executing or executing the computer programs and/or modules stored in the memory and calling data stored in the memory. The memory may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), at least one magnetic disk storage device, a Flash memory device, or other volatile solid state storage device.

Wherein, the module integrated with the terminal device can be stored in a computer readable storage medium if it is implemented in the form of a software functional unit and sold or used as a stand-alone product. Based on such understanding, all or part of the flow in the method according to the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium and used by a processor to implement the steps of the above embodiments of the method. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the apparatus provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.

The embodiment of the invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program runs, the device where the computer-readable storage medium is located is controlled to execute the above-mentioned harmonic superstandard early warning method for the power transmission network node.

In summary, according to the harmonic exceeding warning device of the power transmission network node disclosed in the embodiment of the present invention, after the network condition changes, the maximum harmonic voltage at each node obtained by the calculation is compared with the preset voltage threshold, and if the maximum harmonic voltage at the node is greater than the preset voltage threshold, the harmonic exceeding warning information is generated. By adopting the embodiment of the invention, the distributed generated harmonic source is equivalent to a plurality of nodes in the researched range by adopting the method of actually measured data and formula derivation analysis, whether the harmonic of each node of the power transmission network exceeds the standard or not can be accurately analyzed, the damage of each node device of the power transmission network caused by the harmonic exceeding the standard is effectively avoided, and the power loss is reduced.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.