A method and system for reporting medium and low voltage faults based on power quality analysis

Abstract

The application discloses a kind of based on power quality analysis's middle-low voltage fault reporting method and system, method includes: the power quality data of middle-low voltage node in power grid is collected, and power quality index is calculated according to the power quality data;Judge whether each power quality index is greater than corresponding preset threshold;If a power quality index is greater than the preset threshold corresponding to the power quality index, the fault abnormal type of the power quality data is identified, and the modified impedance value of fault point to monitoring point is calculated using improved impedance method, combined with theoretical impedance, fault section positioning is carried out;According to the identification result and fault section positioning, generate fault reporting information, and send the fault reporting information to monitoring center or operation and maintenance terminal.Can efficiently, accurately lock candidate fault section, and further calculate the accurate position of fault point by algorithm, greatly improve the accuracy and reliability of fault section positioning.

Description

Technical Field

[0001] This invention belongs to the field of medium and low voltage fault location technology, and particularly relates to a medium and low voltage fault reporting method and system based on power quality analysis. Background Technology

[0002] Currently, fault detection and location in medium and low voltage distribution networks mainly rely on traditional overcurrent protection, voltage protection, and fault indicator methods based on data collected by FTUs (Feeder Terminal Units) and DTUs (Distribution Terminal Units). These methods can achieve preliminary judgment of fault sections to a certain extent, but they still have obvious limitations: on the one hand, traditional protection methods have poor selectivity in complex distribution networks with multiple branches and multiple power sources, and are prone to false tripping or failure to trip; on the other hand, fault indicators based on simple threshold comparisons are easily affected by factors such as load fluctuations, current injection from distributed sources, and high-resistance grounding faults, resulting in insufficient sensitivity and accuracy.

[0003] In recent years, with the development of smart grid technology, some fault location methods based on fault waveform characteristics, traveling wave principles, and artificial intelligence algorithms have been proposed. However, these methods either have high requirements for sampling equipment and are expensive, or rely on a large amount of historical data and high computing power, making it difficult to promote and apply them in actual medium and low voltage power distribution scenarios. In particular, for complex situations such as high-resistance grounding and intermittent arcing faults, existing methods often fail to accurately identify the fault location, resulting in fault diagnosis still relying heavily on manual line inspection, which is inefficient and prolongs power outage time for users. Summary of the Invention

[0004] This invention provides a method and system for reporting medium and low voltage faults based on power quality analysis, which solves the technical problem that it is difficult to accurately identify the location of faults, resulting in fault investigation still relying heavily on manual line inspection, which is inefficient and prolongs the 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:

[0006] Power quality data of low-voltage nodes in the power grid are collected, and power quality indicators are calculated based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate.

[0007] Determine whether each power quality indicator exceeds the corresponding preset threshold;

[0008] If a certain power quality index is greater than a preset threshold corresponding to that power quality index, the fault anomaly type of the power quality data is identified, and the corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method. Combined with the theoretical impedance, the fault section is located.

[0009] Based on the identification results and fault location, a fault reporting information is generated and sent to the monitoring center or operation and maintenance terminal.

[0010] Secondly, the present invention provides a medium- and low-voltage fault reporting system based on power quality analysis, comprising:

[0011] The 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. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate.

[0012] The judgment module is configured to determine whether each power quality indicator is greater than the corresponding preset threshold.

[0013] The positioning module is configured to identify the fault anomaly type of the power quality data if a certain power quality index is greater than a preset threshold corresponding to the certain power quality index, and to calculate the corrected impedance value from the fault point to the monitoring point using an improved impedance method, and to locate the fault section by combining the theoretical impedance.

[0014] The reporting module is configured to generate fault reporting information based on the identification results and fault segment location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0015] Thirdly, 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, the instructions being executed by the at least one processor to enable the at least one processor to perform the steps of the low-voltage fault reporting method based on power quality analysis according to any embodiment of the present invention.

[0016] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the program instructions are executed by a processor, the processor performs the steps of the low-voltage fault reporting method based on power quality analysis according to any embodiment of the present invention.

[0017] This application presents a method and system for reporting medium- and low-voltage faults based on power quality analysis. By introducing correction factors such as ground capacitance compensation and voltage changes before and after the fault, it effectively overcomes the measurement error problems caused by unstable line parameters and the complexity of fault characteristics due to the integration of distributed power sources in medium- and low-voltage distribution networks using traditional impedance methods. This significantly improves the accuracy and anti-interference capability of fault impedance calculation. Based on the rapid matching and screening of accurate corrected impedance values ​​with the theoretical impedance values ​​of each section in the power grid topology model, the system can efficiently and accurately locate candidate fault sections and further calculate the precise location of the fault point through algorithms. This greatly improves the accuracy and reliability of fault section location, narrowing the fault search scope from traditional manual line inspection to specific sections or even specific towers. This enables maintenance personnel to respond quickly and perform precise repairs, significantly shortening power outage time and improving power supply reliability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a method for reporting medium- and low-voltage faults based on power quality analysis, provided as an embodiment of the present invention;

[0020] Figure 2 This is a structural block diagram of a medium- and low-voltage fault reporting system based on power quality analysis, provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1 The diagram shows a flowchart of a medium- and low-voltage fault reporting method based on power quality analysis according to this application.

[0024] like Figure 1As shown, the method for reporting medium and low voltage faults based on power quality analysis specifically includes the following steps:

[0025] Step S101: Collect power quality data of low-voltage nodes in the power grid, and calculate power quality indicators based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate.

[0026] In this step, voltage deviation The calculation formula is:

[0027] ,

[0028] In the formula, For actual voltage measurement, Rated voltage;

[0029] Frequency deviation The calculation formula is:

[0030] ,

[0031] In the formula, For the actual system frequency, The rated frequency;

[0032] Total Harmonic Distortion The calculation formula is:

[0033] ,

[0034] In the formula, This is the effective value of the fundamental voltage. The effective value of the h-th harmonic voltage. The highest harmonic order under consideration.

[0035] Step S102: Determine whether each power quality indicator is greater than the corresponding preset threshold.

[0036] In one specific embodiment, after determining whether each power quality indicator is greater than the corresponding preset threshold, if none of the power quality indicators are greater than the corresponding preset threshold, then no fault reporting information is generated directly.

[0037] Step S103: If a certain power quality index is greater than a preset threshold corresponding to the certain power quality index, the fault anomaly type of the power quality data is identified, and the corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method. Combined with the theoretical impedance, the fault section is located.

[0038] In this step, if the voltage deviation exceeds the threshold and continues for a set time, it is identified as a voltage dip or rise; if the frequency deviation exceeds the frequency threshold, it is identified as a frequency exceeding the limit; if the total harmonic distortion exceeds the distortion threshold, it is identified as harmonic exceedance.

[0039] It should be noted that the corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the expression is as follows:

[0040] ,

[0041] ,

[0042] In the formula, To correct the impedance value, For improved impedance, Angular frequency, This refers to the line-to-ground capacitance. for, This is the voltage before the fault. This is the fault voltage. This is the fault current;

[0043] Based on line length in topology model The theoretical impedance is calculated using the unit impedance formula, and the expression is:

[0044] ,

[0045] ,

[0046] In the formula, For theoretical resistance, Unit impedance For resistance components, The imaginary unit of the reactance component. This is the imaginary part used to represent impedance;

[0047] 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.

[0048] On the selected candidate fault sections, the distance from the fault point to the starting point of the candidate fault section is calculated based on the corrected impedance value, expressed as:

[0049] ,

[0050] In the formula, This represents the distance from the fault point to the starting point of the candidate fault section. Resistance per unit length This is the real part operator for complex impedance, which takes the complex resistive component. This is the equivalent impedance on the power supply side.

[0051] Step S104: Generate fault reporting information based on the identification results and fault segment location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0052] In summary, the method presented in this application, by introducing correction factors such as ground capacitance compensation and voltage changes before and after a fault, effectively overcomes the measurement error problems caused by unstable line parameters and the complexity of fault characteristics due to the integration of distributed power sources in medium and low voltage distribution networks using traditional impedance methods. This significantly improves the accuracy and anti-interference capability of fault impedance calculation. Based on the rapid matching and screening of accurate corrected impedance values ​​with the theoretical impedance values ​​of each section in the power grid topology model, the system can efficiently and accurately locate candidate fault sections and further calculate the precise location of the fault point through algorithms. This technical approach greatly improves the accuracy and reliability of fault section location, narrowing the fault search scope from traditional manual line inspection to specific sections or even specific towers, enabling maintenance personnel to respond quickly and perform precise repairs, significantly shortening power outage time and improving power supply reliability. Simultaneously, this automated and intelligent location method reduces reliance on human experience, lowers maintenance costs, and provides core technical support for building an efficient and robust smart distribution network.

[0053] Please see Figure 2 The diagram shows a structural block diagram of a medium- and low-voltage fault reporting system based on power quality analysis according to this application.

[0054] like Figure 2 As shown, the medium and low voltage fault reporting system 200 includes an acquisition module 210, a judgment module 220, a location module 230, and a reporting module 240.

[0055] 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. 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 a corresponding preset threshold. The positioning module 230 is configured to identify the fault anomaly 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 calculate the corrected impedance value from the fault point to the monitoring point using an improved impedance method, and locate the fault section by combining the theoretical impedance. The reporting module 240 is configured to generate fault reporting information based on the identification result and the fault section location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

[0056] It should be understood that Figure 2 The modules and references described in the document Figure 1The steps described in the text correspond to those in the method described above. Therefore, the operations, features, and corresponding technical effects described above also apply to the method described in the text. Figure 2 The various modules in the document will not be described in detail here.

[0057] In other embodiments, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the program instructions are executed by a processor, the processor performs the low-voltage fault reporting method based on power quality analysis in any of the above method embodiments.

[0058] In one embodiment, the computer-readable storage medium of the present invention stores computer-executable instructions, which are configured as follows:

[0059] Power quality data of low-voltage nodes in the power grid are collected, and power quality indicators are calculated based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate.

[0060] Determine whether each power quality indicator exceeds the corresponding preset threshold;

[0061] If a certain power quality index is greater than a preset threshold corresponding to that power quality index, the fault anomaly type of the power quality data is identified, and the corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method. Combined with the theoretical impedance, the fault section is located.

[0062] Based on the identification results and fault location, a fault reporting information is generated and sent to the monitoring center or operation and maintenance terminal.

[0063] Computer-readable storage media may include a stored program area and a stored data area, wherein the stored program area may store an operating system and an application program required for at least one function; the stored data area may store data created based on the use of the power quality analysis-based low-voltage fault reporting system, etc. Furthermore, the computer-readable storage medium may include high-speed random access memory, and may also include memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the computer-readable storage medium may optionally include memory remotely disposed relative to a processor, which can be connected to the power quality analysis-based low-voltage fault reporting system via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0064] Figure 3 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention, such as... Figure 3As 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, memory 320, input device 330, and output device 340 can be connected via a bus or other means. Figure 3 Taking a bus connection as an example, the memory 320 is the computer-readable storage medium described above. The processor 310 executes various server functions and data processing by running non-volatile software programs, instructions, and modules stored in the memory 320, thereby implementing the low-voltage fault reporting method based on power quality analysis described in the above embodiment. The input device 330 can receive input digital or character information and generate key signal inputs related to user settings and function control of the low-voltage fault reporting system based on power quality analysis. The output device 340 may include a display screen or other display device.

[0065] The aforementioned electronic device can execute the method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the method provided in the embodiments of the present invention.

[0066] In one implementation, the above-described electronic device is applied to a low- and medium-voltage fault reporting system based on power quality analysis, for a client, and includes: 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, the instructions being executed by the at least one processor to enable the at least one processor to:

[0067] Power quality data of low-voltage nodes in the power grid are collected, and power quality indicators are calculated based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate.

[0068] Determine whether each power quality indicator exceeds the corresponding preset threshold;

[0069] If a certain power quality index is greater than a preset threshold corresponding to that power quality index, the fault anomaly type of the power quality data is identified, and the corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method. Combined with the theoretical impedance, the fault section is located.

[0070] Based on the identification results and fault location, a fault reporting information is generated and sent to the monitoring center or operation and maintenance terminal.

[0071] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part 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, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the 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: Power quality data of low-voltage nodes in the power grid are collected, and power quality indicators are calculated based on the power quality data. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate. Determine whether each power quality indicator exceeds the corresponding preset threshold; If a certain power quality index exceeds a preset threshold corresponding to that power quality index, the fault anomaly type of the power quality data is identified, and an improved impedance method is used to calculate the corrected impedance value from the fault point to the monitoring point. Combined with theoretical impedance, the fault section is located. The process of calculating the corrected impedance value from the fault point to the monitoring point using the improved impedance method and locating the fault section using theoretical impedance includes: The corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the expression is as follows: ， ， In the formula, To correct the impedance value, For improved impedance, Angular frequency, This refers to the line-to-ground capacitance. This is the voltage before the fault. This is the fault voltage. This is the fault current; Based on line length in topology model The theoretical impedance is calculated using the unit impedance formula, and the expression is: ， In the formula, For theoretical resistance, Unit impedance For resistance components, The imaginary unit of the reactance component. This 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. On the selected candidate fault sections, the distance from the fault point to the starting point of the candidate fault section is calculated based on the corrected impedance value, expressed as: ， In the formula, This represents the distance from the fault point to the starting point of the candidate fault section. Resistance per unit length This is the real part operator for complex impedance, which takes the complex resistive component. This is the equivalent impedance on the power supply side; Based on the identification results and fault location, a fault reporting information is generated and sent to the monitoring center or operation and maintenance terminal.

2. The method for reporting medium and low voltage faults based on power quality analysis according to claim 1, characterized in that, The identification of fault anomaly types in the power quality data includes: If the voltage deviation exceeds the threshold and continues for a set time, it is identified as a voltage dip or surge. If the frequency deviation exceeds the frequency threshold, it is identified as a frequency exceeding the limit; If the total harmonic distortion rate exceeds the distortion rate threshold, it is identified as harmonic over-limit.

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 exceeds a corresponding preset threshold, the method further includes: If all power quality indicators are not greater than the corresponding preset thresholds, no fault reporting information will be generated.

4. A medium- and low-voltage fault reporting system based on power quality analysis, characterized in that, include: The 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. The power quality indicators include voltage deviation, frequency deviation, and total harmonic distortion rate. The judgment module is configured to determine whether each power quality indicator is greater than the corresponding preset threshold. The positioning module is configured to, if a certain power quality index exceeds a preset threshold corresponding to that power quality index, identify the fault anomaly type of the power quality data, calculate the corrected impedance value from the fault point to the monitoring point using an improved impedance method, and locate the fault section by combining it with the theoretical impedance. The step of calculating the corrected impedance value from the fault point to the monitoring point using the improved impedance method and locating the fault section by combining it with the theoretical impedance includes: The corrected impedance value from the fault point to the monitoring point is calculated using the improved impedance method, and the expression is as follows: ， ， In the formula, To correct the impedance value, For improved impedance, Angular frequency, This refers to the line-to-ground capacitance. This is the voltage before the fault. This is the fault voltage. This is the fault current; Based on line length in topology model The theoretical impedance is calculated using the unit impedance formula, and the expression is: ， In the formula, For theoretical resistance, Unit impedance For resistance components, The imaginary unit of the reactance component. This 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. On the selected candidate fault sections, the distance from the fault point to the starting point of the candidate fault section is calculated based on the corrected impedance value, expressed as: ， In the formula, This represents the distance from the fault point to the starting point of the candidate fault section. Resistance per unit length This is the real part operator for complex impedance, which takes the complex resistive component. This is the equivalent impedance on the power supply side; The reporting module is configured to generate fault reporting information based on the identification results and fault segment location, and send the fault reporting information to the monitoring center or operation and maintenance terminal.

5. 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 to enable the at least one processor to perform the method according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method according to any one of claims 1 to 3.

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