Medium and low voltage fault reporting method and system based on electric energy quality analysis

Abstract

The invention discloses a medium and low voltage fault reporting method and system based on electric energy quality analysis, and the method comprises the steps: collecting the electric energy quality data of medium and low voltage nodes of a power grid, and carrying out the calculation of an electric energy quality index according to the electric energy quality data; judging whether each electric energy quality index is greater than a corresponding preset threshold value or not; if a certain electric energy quality index is greater than a preset threshold value corresponding to the certain electric energy quality index, identifying a fault abnormity type of the electric energy quality data, calculating a corrected impedance value from a fault point to a monitoring point by adopting an improved impedance method, and positioning a fault section in combination with theoretical impedance; and generating fault reporting information according to the identification result and the fault section positioning, and sending the fault reporting information to a monitoring center or an operation and maintenance terminal. The candidate fault section can be efficiently and accurately locked, the accurate position of the fault point is further calculated through an algorithm, and the accuracy and reliability of fault section positioning are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medium and low voltage fault location, and in particular relates to a medium and low voltage fault reporting method and system based on power quality analysis. Background Art

[0002] Currently, fault detection and location in medium and low voltage distribution networks primarily rely on traditional overcurrent protection, voltage protection, and fault indicator methods based on data collected by feeder terminal units (FTUs) and distribution terminal units (DTUs). While these methods can provide a preliminary assessment of the faulty section to a certain extent, they still have significant limitations. For one thing, traditional protection methods lack selectivity in complex distribution networks with multiple branches and power sources, making them prone to false trips or failures. Furthermore, fault indicators based on simple threshold comparisons are susceptible to load fluctuations, current injection from distributed generation (DGs), and high-resistance ground faults, resulting in insufficient sensitivity and accuracy.

[0003] In recent years, with the development of smart grid technology, several fault location methods based on fault waveform characteristics, traveling wave principles, and artificial intelligence algorithms have been proposed. However, these methods often face significant challenges in their widespread application in practical medium and low voltage distribution scenarios due to their demanding and expensive sampling equipment or their reliance on extensive historical data and high computing power. Existing methods often struggle to accurately identify fault locations in complex situations, such as high-resistance grounding and intermittent arc faults. Consequently, fault troubleshooting still relies heavily on manual line inspections, which is inefficient and prolongs power outages for users. Summary of the Invention

[0004] The present invention provides a medium and low voltage fault reporting method and system based on power quality analysis, which is used to solve the technical problem that it is difficult to accurately identify the fault location, resulting in fault troubleshooting still relying heavily on manual line inspections, which is inefficient and prolongs power outage time for users.

[0005] In a first aspect, the present invention provides a method for reporting medium and low voltage faults based on power quality analysis, comprising: Collecting power quality data of low-voltage nodes in the power grid and calculating power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; Determine whether each power quality indicator is greater than the corresponding preset threshold; If a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, the fault abnormality type of the power quality data is identified, and the modified impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the fault section is located in combination with the theoretical impedance; Generate fault reporting information based on the identification result and fault section location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0006] In a second aspect, the present invention provides a medium and low voltage fault reporting system based on power quality analysis, comprising: An acquisition module is configured to collect power quality data of low-voltage nodes in the power grid and calculate power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; A judgment module configured to judge whether each power quality indicator is greater than a corresponding preset threshold; a positioning module configured to identify the fault anomaly type of the power quality data if a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, and calculate the corrected impedance value from the fault point to the monitoring point using an improved impedance method, and locate the fault section in combination with the theoretical impedance; The reporting module is configured to generate fault reporting information according to the identification result and the fault section location, and send the fault reporting information to the monitoring center or the operation and maintenance terminal.

[0007] According to a third aspect, an electronic device is provided, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the steps of the medium and low voltage fault reporting method based on power quality analysis according to any embodiment of the present invention.

[0008] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the program instructions are executed by a processor, the processor executes the steps of the medium and low voltage fault reporting method based on power quality analysis of any embodiment of the present invention.

[0009] The medium and low voltage fault reporting method and system based on power quality analysis of the present application effectively overcomes the measurement error problem caused by the traditional impedance method in medium and low voltage distribution networks due to unstable line parameters and the complexity of fault characteristics caused by the access of distributed power sources, by introducing correction factors such as ground capacitance compensation and voltage change before and after the fault. It greatly improves the accuracy and anti-interference ability of fault impedance calculation. Based on the rapid matching and screening of accurate corrected impedance values ​​and theoretical impedance values ​​of each section in the power grid topology model, the system can efficiently and accurately lock candidate fault sections, and further calculate the precise location of the fault point through an algorithm, greatly improving the accuracy and reliability of fault section positioning, and narrowing the fault search range from traditional manual line patrol to specific sections or even specific towers, enabling operation and maintenance personnel to respond quickly and carry out precise maintenance, significantly shortening the fault outage time, and improving power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0011] Figure 1 A flowchart of a method for reporting medium and low voltage faults based on power quality analysis provided by one embodiment of the present invention; Figure 2 A structural block diagram of a medium and low voltage fault reporting system based on power quality analysis provided by one embodiment of the present invention; Figure 3 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0013] See also Figure 1 , which shows a flow chart of a medium and low voltage fault reporting method based on power quality analysis of the present application.

[0014] like Figure 1 As shown, the method for reporting medium and low voltage faults based on power quality analysis specifically includes the following steps: Step S101 : collecting power quality data of low-voltage nodes in a power grid, and calculating power quality indicators based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion.

[0015] In this step, the voltage deviation The calculation formula is: , Where, To actually measure the voltage, is the rated voltage; Frequency deviation The calculation formula is: , Where, is the actual system frequency, is the rated frequency; Total harmonic distortion The calculation formula is: , Where, is the effective value of the fundamental voltage, is the effective value of the hth harmonic voltage, is the highest harmonic order considered.

[0016] Step S102: determine whether each power quality indicator is greater than a corresponding preset threshold.

[0017] In a specific embodiment, after determining whether each power quality indicator is greater than a corresponding preset threshold, if each power quality indicator is not greater than the corresponding preset threshold, fault reporting information is not directly generated.

[0018] Step S103: If a certain power quality indicator is greater than a preset threshold value corresponding to the power quality indicator, the fault abnormality type of the power quality data is identified, and the improved impedance method is used to calculate the corrected impedance value from the fault point to the monitoring point, and the fault section is located in combination with the theoretical impedance.

[0019] In this step, if the voltage deviation exceeds the threshold and lasts for the set time, it is identified as a voltage sag or swell; if the frequency deviation exceeds the frequency threshold, it is identified as a frequency limit violation; if the total harmonic distortion rate exceeds the distortion rate threshold, it is identified as a harmonic excess.

[0020] It should be noted that the modified impedance value from the fault point to the monitoring point is calculated according to the improved impedance method, and the expression is: , , Where, To correct the impedance value, For improved impedance, is the angular frequency, is the line-to-ground capacitance, for, is the voltage before the fault, is the fault voltage, is the fault current; Based on the line length in the topology model The theoretical impedance is calculated by using the unit impedance: , , Where, For theoretical resistance, is the unit impedance, is the resistance component, is the imaginary unit of the reactance component, is the imaginary part used to represent impedance; The calculated corrected impedance value is matched with each theoretical impedance value, and the section with the smallest error is selected as the candidate fault section; In the selected candidate fault section, the distance between the fault point and the starting point of the candidate fault section is calculated according to the corrected impedance value. The expression is: , Where, is the distance between the fault point and the starting point of the candidate fault section, is the resistance per unit length, is the real part operator of the complex impedance, that is, taking the complex resistance component, is the equivalent impedance on the power supply side.

[0021] Step S104: generating fault reporting information based on the identification result and the fault section location, and sending the fault reporting information to a monitoring center or an operation and maintenance terminal.

[0022] In summary, the method of the present application, by introducing correction factors such as ground capacitance compensation and voltage change before and after the fault, effectively overcomes the measurement error problem caused by the traditional impedance method in medium and low voltage distribution networks due to unstable line parameters and the complexity of fault characteristics caused by the access of distributed power sources, and greatly improves the accuracy and anti-interference ability of fault impedance calculation. Based on the rapid matching and screening of accurate corrected impedance values ​​and theoretical impedance values ​​of each section in the power grid topology model, the system can efficiently and accurately lock the candidate fault section, and further calculate the precise location of the fault point through the algorithm. This technical means greatly improves the accuracy and reliability of fault section positioning, and narrows the fault search range from traditional manual line patrol to specific sections or even specific towers, enabling operation and maintenance personnel to respond quickly and carry out precise maintenance, significantly shortening the fault outage time and improving power supply reliability. At the same time, this automated and intelligent positioning method reduces dependence on manual experience, reduces operation and maintenance costs, and provides core technical support for building an efficient and strong smart distribution network.

[0023] See also Figure 2 , which shows a structural block diagram of a medium and low voltage fault reporting system based on power quality analysis of the present application.

[0024] like Figure 2 As shown, the medium and low voltage fault reporting system 200 includes an acquisition module 210 , a judgment module 220 , a positioning module 230 and a reporting module 240 .

[0025] Among them, the acquisition module 210 is configured to collect power quality data of low-voltage nodes in the power grid, and calculate power quality indicators based on the power quality data, and the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; the judgment module 220 is configured to judge whether each power quality indicator is greater than the corresponding preset threshold; the positioning module 230 is configured to identify the fault abnormality type of the power quality data if a certain power quality indicator is greater than the preset threshold corresponding to the certain power quality indicator, and use the improved impedance method to calculate the corrected impedance value from the fault point to the monitoring point, and combine the theoretical impedance to locate the fault section; the reporting module 240 is configured to generate fault reporting information based on the identification result and fault section positioning, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0026] It should be understood that Figure 2 Modules and references documented in Figure 1 Therefore, the operations and features described above for the method and the corresponding technical effects also apply to Figure 2 The modules in it will not be described in detail here.

[0027] In other embodiments, embodiments of the present invention further provide a computer-readable storage medium having a computer program stored thereon, wherein when the program instructions are executed by a processor, the processor is caused to execute the medium and low voltage fault reporting method based on power quality analysis in any of the above method embodiments; As an embodiment, the computer-readable storage medium of the present invention stores computer-executable instructions, and the computer-executable instructions are configured as follows: Collecting power quality data of low-voltage nodes in the power grid and calculating power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; Determine whether each power quality indicator is greater than the corresponding preset threshold; If a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, the fault abnormality type of the power quality data is identified, and the modified impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the fault section is located in combination with the theoretical impedance; Generate fault reporting information based on the identification result and fault section location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0028] The computer-readable storage medium may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the medium and low voltage fault reporting system based on power quality analysis, etc. Furthermore, the computer-readable storage medium may include high-speed random access memory and may also include a memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state memory device. In some embodiments, the computer-readable storage medium may optionally include a memory remotely located relative to the processor, and these remote memories may be connected to the medium and low voltage fault reporting system based on power quality analysis via a network. Examples of the aforementioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0029] Figure 3 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention, such as Figure 3 As shown, the device includes: a processor 310 and a memory 320. The electronic device may also include: an input device 330 and an output device 340. The processor 310, the memory 320, the input device 330 and the output device 340 may be connected via a bus or other means. Figure 3 The example of a bus connection is shown. Memory 320 is the aforementioned computer-readable storage medium. Processor 310 executes various server functional applications and data processing by running the non-volatile software programs, instructions, and modules stored in memory 320, thereby implementing the medium and low voltage fault reporting method based on power quality analysis described in the aforementioned method embodiment. Input device 330 can receive input digital or character information and generate key signal input related to user settings and function control of the medium and low voltage fault reporting system based on power quality analysis. Output device 340 can include a display device such as a display screen.

[0030] The electronic device can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0031] As an embodiment, the electronic device is applied to a medium and low voltage fault reporting system based on power quality analysis, and is used for a client, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to: Collecting power quality data of low-voltage nodes in the power grid and calculating power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; Determine whether each power quality indicator is greater than the corresponding preset threshold; If a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, the fault abnormality type of the power quality data is identified, and the modified impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the fault section is located in combination with the theoretical impedance; Generate fault reporting information based on the identification result and fault section location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0032] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods of each embodiment or certain portions of the embodiments.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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. However, 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.

Claims

1. A method for reporting medium and low voltage faults based on power quality analysis, characterized in that: include: Collecting power quality data of low-voltage nodes in the power grid and calculating power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; Determine whether each power quality indicator is greater than the corresponding preset threshold; If a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, the fault abnormality type of the power quality data is identified, and the modified impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the fault section is located in combination with the theoretical impedance; Generate fault reporting information based on the identification result and fault section location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

2. A method for reporting medium and low voltage faults based on power quality analysis according to claim 1, characterized in that: The identifying of the fault anomaly type of the power quality data includes: If the voltage deviation exceeds the threshold and lasts for a set time, it is identified as a voltage sag or swell; If the frequency deviation exceeds the frequency threshold, it is identified as a frequency limit violation; If the total harmonic distortion rate exceeds the distortion rate threshold, it is identified as harmonic excess.

3. The method for reporting medium and low voltage faults based on power quality analysis according to claim 1, characterized in that: After determining whether each power quality indicator is greater than a corresponding preset threshold, the method further includes: If the power quality indicators are not greater than the corresponding preset thresholds, no fault reporting information is generated.

4. A method for reporting medium and low voltage faults based on power quality analysis according to claim 1, characterized in that: The improved impedance method is used to calculate the corrected impedance value from the fault point to the monitoring point, and the fault section is located in combination with the theoretical impedance. The method includes: According to the improved impedance method, the corrected impedance value from the fault point to the monitoring point is calculated as follows: ， ， Where, To correct the impedance value, For improved impedance, is the angular frequency, is the line-to-ground capacitance, for, is the voltage before the fault, is the fault voltage, is the fault current; Based on the line length in the topology model The theoretical impedance is calculated by using the unit impedance: ， ， Where, For theoretical resistance, is the unit impedance, is the resistance component, is the imaginary unit of the reactance component, is the imaginary part used to represent impedance; The calculated corrected impedance value is matched with each theoretical impedance value, and the section with the smallest error is selected as the candidate fault section; In the selected candidate fault section, the distance between the fault point and the starting point of the candidate fault section is calculated according to the corrected impedance value. The expression is: ， Where, is the distance between the fault point and the starting point of the candidate fault section, is the resistance per unit length, is the real part operator of the complex impedance, that is, taking the complex resistance component, is the equivalent impedance on the power supply side.

5. A medium and low voltage fault reporting system based on power quality analysis, characterized in that: include: An acquisition module is configured to collect power quality data of low-voltage nodes in the power grid and calculate power quality indicators based on the power quality data, wherein the power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate; A judgment module configured to judge whether each power quality indicator is greater than a corresponding preset threshold; a positioning module configured to identify the fault anomaly type of the power quality data if a certain power quality indicator is greater than a preset threshold value corresponding to the certain power quality indicator, and calculate the corrected impedance value from the fault point to the monitoring point using an improved impedance method, and locate the fault section in combination with the theoretical impedance; The reporting module is configured to generate fault reporting information according to the identification result and the fault section location, and send the fault reporting information to the monitoring center or the operation and maintenance terminal.

6. An electronic device, characterized in that: include: At least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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