A power distribution network single-phase ground fault section positioning detection method

Abstract

The application belongs to the technical field of single-phase grounding fault detection, and provides a distribution network single-phase grounding fault section positioning detection method, which comprises the following steps: step 1, obtaining each-phase magnetic field at each magnetic field sensor of each feeder; step 2, calculating zero sequence components of each-phase magnetic field of each feeder; and step 3, decomposing the calculated zero sequence magnetic field to the horizontal direction and the vertical direction; the application collects each-phase magnetic field information at each magnetic field sensor of each feeder, calculates zero sequence magnetic field components, further decomposes the zero sequence magnetic field to the horizontal and vertical directions, extracts the zero sequence magnetic field horizontal component and performs multiplication calculation, and finally determines the fault section according to the sign change of the multiplication result; thereby effectively improving the positioning accuracy and reliability, reducing the influence of system operation mode and transition resistance on the positioning result, realizing the rapid and accurate determination of the fault section, and providing a strong guarantee for the safe and stable operation of the distribution network.

Description

Technical Field

[0001] This invention belongs to the field of single-phase grounding fault detection technology, specifically a method for locating and detecting single-phase grounding fault sections in a power distribution network. Background Technology

[0002] Single-phase grounding faults are a common type of fault in the operation of power distribution networks, and their accurate and rapid location is crucial for ensuring the safe and stable operation of the power grid.

[0003] However, traditional fault location methods often suffer from low location accuracy and are greatly affected by system operating mode and transition resistance, making it difficult to accurately determine the fault section, prolonging fault repair time, increasing the power outage area and economic losses.

[0004] Therefore, developing an efficient and accurate technology for locating single-phase grounding fault sections in power distribution networks has become an urgent problem to be solved in the power industry. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for locating and detecting single-phase grounding fault sections in a power distribution network. This method solves the problems of low location accuracy and significant influence from system operation mode and transition resistance in existing fault location methods. These problems make it difficult to accurately determine the fault section, prolonging fault repair time, increasing the power outage area, and causing economic losses.

[0006] A method for locating and detecting single-phase ground fault sections in a power distribution network includes the following steps:

[0007] Step 1: Data Acquisition: Obtain the magnetic field of each phase at each magnetic field sensor along each feeder. ,in, For the three phases of the feeder, k is the line number. Number the magnetic field sensor;

[0008] Step 2: Obtain the zero-sequence magnetic field components: Calculate the zero-sequence components of the magnetic field of each phase of each feeder. ;

[0009] Step 3: Magnetic field decomposition: Decompose the calculated zero-sequence magnetic field into the horizontal direction. and vertical direction ;

[0010] Step 4: Extract the horizontal direction of the zero-sequence magnetic field of each magnetic field sensor on each feeder. The product is multiplied starting from the first magnetic field sensor on each feeder, and the cumulative product X is calculated. ln ;

[0011] Step 5: Detection Criteria: During the detection process, we use the cumulative multiplication result X... lnThe sign change is used to determine the faulty section.

[0012] Preferably, the specific process of step 1 is as follows:

[0013] Step 1.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance from each phase feeder to the installation location of the magnetic field sensor. ;

[0014] Step 1.2: Obtain the phase magnetic field information of each magnetic field sensor on each feeder:

[0015]

[0016] In the formula, r is the vacuum permeability. j This represents the distance from each phase line to the installation location of the magnetic field sensor. This represents the current at each magnetic field sensor on each feeder.

[0017] Preferably, step 2 is specifically performed as follows:

[0018] Step 2: Calculate the zero-sequence component of each phase magnetic field of the magnetic field sensor on each feeder line using the symmetrical component method. :

[0019]

[0020] In the formula, The zero-sequence magnetic field of phase A is the first magnetic field sensor of line 1. The zero-sequence current calculation formula for phases B and C is the same as that for phase A.

[0021] Preferably, the specific process of step 3 is as follows:

[0022] Step 3.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance between each phase line and the magnetic field sensor. and the angle formed by each phase feeder and the sensor ;

[0023] Step 3.2: Decompose the zero-sequence magnetic field vector into horizontal and vertical components:

[0024]

[0025] In the formula, and These are the horizontal and vertical components of the zero-sequence magnetic field vector decomposition, respectively. This refers to the angle formed between each phase feeder and the magnetic field sensor.

[0026] Preferably, the specific process of step 4 is as follows:

[0027] Step 4.1: Perform vector superposition of the zero-sequence magnetic field horizontal components of the magnetic field sensor:

[0028]

[0029] In the formula, These represent the horizontal components of the zero-sequence magnetic field for phases A, B, and C, respectively. This is the vector sum of the horizontal components of the zero-sequence magnetic field;

[0030] Step 4.2: Define the direction sign function :

[0031]

[0032] Step 4.3: Perform a cumulative multiplication calculation on the first feeder line from the first magnetic field sensor to the nth magnetic field sensor, and record the cumulative multiplication result as X. ln :

[0033]

[0034] In the formula, l is the feeder number and n is the sensor number.

[0035] Preferably, the specific criterion process for step 5 is as follows:

[0036] If the cumulative product result X ln In the first magnetic field sensor (i.e. X) 11 If the value of (point) is negative, then the faulty section is directly determined to be between the first and second measuring points of the feeder;

[0037] If the cumulative product result X ln In the first magnetic field sensor (X) 11 If the value of the multiplication result is not negative, we continue to monitor the cumulative multiplication result of the subsequent sensors. When the cumulative multiplication result is negative for the first time, we further observe the cumulative multiplication result of the subsequent sensors. If the cumulative multiplication result maintains the same sign (i.e., does not change sign) for two or more consecutive times starting from the negative value, we determine that the faulty section is located between the measurement point where the last sign change occurred and the next measurement point.

[0038] A single-phase grounding fault location and detection system for a distribution network, utilizing the aforementioned method for locating and detecting single-phase grounding fault sections in a distribution network, includes:

[0039] The data acquisition module is used to acquire the magnetic field of each phase at each magnetic field sensor on each feeder. ,in, For the three phases of the feeder, k is the line number. Number the magnetic field sensor;

[0040] The zero-sequence magnetic field component calculation module, connected to the data acquisition module, is used to calculate the zero-sequence component of the magnetic field of each phase of each feeder based on the acquired magnetic field information of each phase. ;

[0041] The magnetic field decomposition module, connected to the zero-sequence magnetic field component calculation module, is used to decompose the calculated zero-sequence magnetic field into horizontal components. and vertical direction ;

[0042] The zero-sequence magnetic field horizontal component processing module, connected to the magnetic field decomposition module, is used to extract the zero-sequence magnetic field horizontal component of each magnetic field sensor on each feeder. And perform vector superposition;

[0043] The cumulative multiplication calculation module, connected to the zero-sequence magnetic field horizontal component processing module, is used to perform cumulative multiplication calculations on the zero-sequence magnetic field horizontal components, starting from the first magnetic field sensor of feeder 1, to obtain the cumulative multiplication result X. ln ;

[0044] The fault criterion module, connected to the cumulative multiplication calculation module, is used to determine the fault based on the cumulative multiplication result X. ln The sign change determines the faulty section.

[0045] A processor is configured to execute the single-phase ground fault location and detection method for power distribution networks as described above.

[0046] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for locating and detecting single-phase grounding fault sections in a power distribution network.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention collects phase magnetic field information from each magnetic field sensor on each feeder and calculates the zero-sequence magnetic field component. It further decomposes the zero-sequence magnetic field into horizontal and vertical directions, extracts the horizontal component, and performs cumulative multiplication. Finally, it determines the fault section based on the sign change of the cumulative multiplication result. This effectively improves the accuracy and reliability of fault location, reduces the impact of system operating mode and transition resistance on the location results, and achieves rapid and accurate fault section identification, providing strong support for the safe and stable operation of the distribution network. Attached Figure Description

[0049] Figure 1 This is a flowchart of the fault detection process of the present invention;

[0050] Figure 2This is the zero-sequence magnetic field vector diagram of the present invention;

[0051] Figure 3 This is a model diagram of the 10kV ungrounded system of the present invention;

[0052] Figure 4 The diagram shows the horizontal zero-sequence magnetic field waveforms of each feeder in this invention. Detailed Implementation

[0053] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0054] Example: This invention provides a method for locating and detecting single-phase grounding fault sections in a power distribution network, such as... Figure 1 As shown, it includes the following steps:

[0055] Step 1: Data Acquisition: Obtain the magnetic field of each phase at each magnetic field sensor along each feeder. ,in, For the three phases of the feeder, k is the line number. Number the magnetic field sensor;

[0056] Step 2: Obtain the zero-sequence magnetic field components: Calculate the zero-sequence components of the magnetic field of each phase of each feeder. ;

[0057] Step 3: Magnetic field decomposition: Decompose the calculated zero-sequence magnetic field into the horizontal direction. and vertical direction ;

[0058] Step 4: Extract the horizontal direction of the zero-sequence magnetic field of each magnetic field sensor on each feeder. The product is multiplied starting from the first magnetic field sensor on each feeder, and the cumulative product X is calculated. ln ;

[0059] Step 5: Detection Criteria: During the detection process, we use the cumulative multiplication result X... ln The sign change is used to determine the faulty section.

[0060] As shown above, this method collects the phase magnetic field information from each magnetic field sensor of each feeder, calculates the zero-sequence magnetic field component and decomposes it into horizontal and vertical directions, extracts the horizontal component of the zero-sequence magnetic field and performs cumulative multiplication calculation, and accurately determines the fault section based on the sign change of the cumulative multiplication result. This method effectively improves the accuracy and reliability of fault location, reduces the impact of system operating mode and transition resistance on the location results, and achieves rapid and accurate judgment of fault sections, providing a strong guarantee for the safe and stable operation of the distribution network.

[0061] Specifically, the process of step 1 is as follows:

[0062] Step 1.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance from each phase feeder to the installation location of the magnetic field sensor. ;

[0063] Step 1.2: Obtain the phase magnetic field information of each magnetic field sensor on each feeder:

[0064]

[0065] In the formula, r is the vacuum permeability. j This represents the distance from each phase line to the installation location of the magnetic field sensor. This represents the current at each magnetic field sensor on each feeder.

[0066] As shown above, firstly, based on the tower structure and the installation location of the magnetic field sensors, the distance from each phase feeder to the magnetic field sensor is accurately obtained. Then, using this distance information, along with the current at each magnetic field sensor on each feeder, and combined with the vacuum permeability, the magnetic field information of each phase at each magnetic field sensor on each feeder is accurately calculated. This provides a detailed data foundation for subsequent precise fault location, effectively improving the accuracy and reliability of fault location. Compared with existing technologies, it reduces location errors caused by inaccurate data, providing stronger support for the safe and stable operation of the distribution network.

[0067] Specifically, step 2 involves the following process:

[0068] Step 2: Calculate the zero-sequence component of each phase magnetic field of the magnetic field sensor on each feeder line using the symmetrical component method. :

[0069]

[0070] In the formula, The zero-sequence magnetic field of phase A is the first magnetic field sensor of line 1. The zero-sequence current calculation formula for phases B and C is the same as that for phase A.

[0071] As shown above, by applying the symmetrical component method, the zero-sequence component of the magnetic field of each phase of the magnetic field sensor on each feeder can be accurately calculated. In this step, the calculation is performed using phase A of the first magnetic field sensor on line 1 as an example, while ensuring that the calculation formulas for phases B and C are consistent with those for phase A, thus guaranteeing the uniformity and accuracy of the calculation. Compared with existing technologies, this method effectively improves the accuracy of zero-sequence component calculation, provides a reliable basis for the accurate location of subsequent fault sections, reduces location errors caused by calculation errors, and enhances the efficiency and safety of distribution network fault handling.

[0072] Specifically, the process of step 3 is as follows:

[0073] Step 3.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance between each phase line and the magnetic field sensor. and the angle formed by each phase feeder and the sensor ;

[0074] Step 3.2: Decompose the zero-sequence magnetic field vector into horizontal and vertical components:

[0075]

[0076] In the formula, and These are the horizontal and vertical components of the zero-sequence magnetic field vector decomposition, respectively. This refers to the angle formed between each phase feeder and the magnetic field sensor.

[0077] As shown above, the first step involves accurately determining the distance between each phase line and the magnetic field sensor, as well as the angle between them, based on the tower structure and the installation location of the magnetic field sensor. These parameters are then used to accurately decompose the zero-sequence magnetic field vector into horizontal and vertical components. Compared to existing technologies, this step can more precisely characterize the spatial distribution features of the zero-sequence magnetic field, improving the accuracy of magnetic field decomposition. This provides a richer information basis for the subsequent accurate location of fault sections, helping to reduce location errors and improve the efficiency and accuracy of distribution network fault handling.

[0078] Specifically, the process of step 4 is as follows:

[0079] Step 4.1: Perform vector superposition of the zero-sequence magnetic field horizontal components of the magnetic field sensor:

[0080]

[0081] In the formula, These represent the horizontal components of the zero-sequence magnetic field for phases A, B, and C, respectively. This is the vector sum of the horizontal components of the zero-sequence magnetic field;

[0082] Step 4.2: Define the direction sign function :

[0083]

[0084] Step 4.3: Perform a cumulative multiplication calculation on the first feeder line from the first magnetic field sensor to the nth magnetic field sensor, and record the cumulative multiplication result as X. ln :

[0085]

[0086] In the formula, l is the feeder number and n is the sensor number.

[0087] As shown above, the horizontal components of the three-phase zero-sequence magnetic field (A, B, C) detected by the magnetic field sensors are first vector-superimposed to obtain the synthesized horizontal component of the zero-sequence magnetic field. Then, a direction sign function is defined to quantify the magnetic field direction. Finally, a cumulative multiplication calculation is performed on the first feeder line from the first magnetic field sensor to the nth magnetic field sensor to obtain the cumulative multiplication result X. ln Compared to existing technologies, this step, through vector superposition and cumulative calculation, more accurately captures fault characteristics, improves the accuracy and reliability of fault location, and provides strong support for rapid repair of distribution network faults.

[0088] Specifically, the specific criterion process for step 5 is as follows:

[0089] If the cumulative product result X ln In the first magnetic field sensor (i.e. X) 11 If the value of (point) is negative, then the faulty section is directly determined to be between the first and second measuring points of the feeder;

[0090] If the cumulative product result X ln In the first magnetic field sensor (X) 11 If the value of the multiplication result at point m is not negative, we continue to monitor the cumulative multiplication result of subsequent sensors. When the cumulative multiplication result is negative for the first time, we further observe the cumulative multiplication result of subsequent sensors. If, starting from this negative value, the cumulative multiplication result maintains the same sign (i.e., the sign does not change) for two or more consecutive times, then the fault section is determined to be located between the measurement point where the sign last changed and the next measurement point. That is, if the same sign appears at measurement point m, then the fault point is located between measurement point m and m+1.

[0091] As shown above, by analyzing the sign changes of the cumulative multiplication results, it is determined that if the signs of subsequent results at measurement point m remain the same after the first negative sign appears, the fault point is located between measurement points m and m+1. Compared with existing technologies, this step can more quickly and accurately locate the fault section, reduce the scope and time of manual investigation, improve fault handling efficiency, and enhance the reliability of the location results, providing a strong guarantee for the safe and stable operation of the power distribution network.

[0092] Working principle: First, by collecting the phase magnetic field information of each phase of each magnetic field sensor of each feeder, the zero-sequence magnetic field component is calculated and decomposed into horizontal and vertical directions; then, the horizontal component of the zero-sequence magnetic field is extracted and vector superposition and cumulative multiplication are performed; finally, based on the sign change characteristics of the cumulative multiplication result, that is, if the sign of the subsequent results remains the same after the first negative sign appears, the fault point is determined to be located between the corresponding measurement points, thereby realizing the rapid and accurate judgment of the fault section.

[0093] Application examples

[0094] As shown in the attached diagram. Figure 3 The simulation model of the 10kV ungrounded system is shown. Three feeders, L1 to L3, are set as overhead lines. Magnetic field sensors are installed on the towers of these overhead lines. The fault is assumed to occur at a point 8km along the L3 overhead line, with phase A grounding fault, initial phase angle β = 0°, and grounding resistance of 200Ω. The line parameters are shown in Table 1.

[0095] Table 1 Overhead Line Parameters

[0096] Positive sequence resistance (Ω / km) Positive sequence inductance (mH / km) Positive sequence capacitance (μF / km) Zero-sequence resistance (Ω / km) Zero-sequence inductance (mH / km) Zero-sequence capacitance (μF / km) Overhead line 0.1700 1.2100 0.0097 0.2300 5.4780 0.0080

[0097] Combination Figure 2 The magnetic field vector diagram shown and Figure 4 The waveforms of the horizontal zero-sequence magnetic field for each feeder shown demonstrate how the zero-sequence magnetic field sensed by the magnetic field sensor after a fault is decomposed into horizontal and vertical magnetic field components. The horizontal direction of the zero-sequence magnetic field from each magnetic field sensor on each feeder is then extracted. It can be seen that there is a significant difference in the direction of the horizontal zero-sequence magnetic field between the faulty line and the healthy line. To verify the adaptability of the section location detection method based on magnetic field direction, the proposed method was used to calculate the cumulative results from the first magnetic field sensor to the last magnetic field sensor of each feeder. Simulation verification was carried out under various typical fault conditions, and the results are shown in Table 2.

[0098] Table 2 Simulation verification results

[0099] Section location Initial phase angle β <![CDATA[R g / Oh]]> <![CDATA[Cumulative multiplication result X ln > Judgment Result <![CDATA[L3 feeder 2-3]]> 0° 50 [1 1 1 1 1 1 -1 1 1] <![CDATA[Fault in section 2-3 of L3 line]]> <![CDATA[L1 feeder 1-2]]> 0° 100 [-1 -1 -1 -1 -1 -1 -1 -1 -1] <![CDATA[Fault in section 1-2 of line L1]]> <![CDATA[L2 feeder 2-3]]> 30° 100 [1 1 1 -1 1 1 1 1 1] <![CDATA[Fault in section 2 - 3 of line L2]]>

[0100] The table above shows the simulation verification results, detailing the different locations in each section, initial phase angle β, and grounding resistance R. g Under the given conditions, the cumulative result X calculated by applying the proposed method for locating and detecting single-phase ground fault sections in distribution networks is... ln And its judgment results.

[0101] As shown above, by constructing a 10kV ungrounded system simulation model and setting specific line parameters and fault conditions (such as a phase A ground fault occurring 8km along the L3 overhead line, with an initial phase angle β=0° and a grounding resistance of 200Ω), and combining the magnetic field vector diagram and the horizontal zero-sequence magnetic field waveform diagrams of each feeder, the changes in the zero-sequence magnetic field sensed by the magnetic field sensor after the fault occurred are illustrated in detail. By applying the proposed fault section location and detection method, the simulation data was processed and analyzed. Finally, the fault section was accurately determined by the sign change of the cumulative multiplication result, verifying the adaptability and reliability of the method and providing strong support for the rapid and accurate identification of single-phase ground faults in distribution networks.

[0102] A single-phase grounding fault location and detection system for a distribution network, utilizing the aforementioned method for locating and detecting single-phase grounding fault sections in a distribution network, includes:

[0103] The data acquisition module is used to acquire the magnetic field of each phase at each magnetic field sensor on each feeder. ,in, The feeder consists of three phases, and k is the line number. Number the magnetic field sensor;

[0104] The zero-sequence magnetic field component calculation module, connected to the data acquisition module, is used to calculate the zero-sequence component of the magnetic field of each phase of each feeder based on the acquired magnetic field information of each phase. ;

[0105] The magnetic field decomposition module, connected to the zero-sequence magnetic field component calculation module, is used to decompose the calculated zero-sequence magnetic field into horizontal components. and vertical direction ;

[0106] The zero-sequence magnetic field horizontal component processing module, connected to the magnetic field decomposition module, is used to extract the zero-sequence magnetic field horizontal component of each magnetic field sensor on each feeder. And perform vector superposition;

[0107] The cumulative multiplication calculation module, connected to the zero-sequence magnetic field horizontal component processing module, is used to perform cumulative multiplication calculations on the zero-sequence magnetic field horizontal components, starting from the first magnetic field sensor of feeder 1, to obtain the cumulative multiplication result X. ln ;

[0108] The fault criterion module, connected to the cumulative multiplication calculation module, is used to determine the fault based on the cumulative multiplication result X. ln The sign change determines the faulty section.

[0109] As shown above, the system acquires the phase magnetic field information of each feeder and each magnetic field sensor through the data acquisition module, accurately calculates the zero-sequence magnetic field component through the zero-sequence magnetic field component calculation module, decomposes the zero-sequence magnetic field into horizontal and vertical directions through the magnetic field decomposition module, extracts and superimposes the horizontal component through the zero-sequence magnetic field horizontal component processing module, performs cumulative multiplication calculation through the cumulative multiplication module, and finally, the fault judgment module accurately determines the fault section based on the sign change of the cumulative multiplication result. This effectively improves the accuracy and reliability of fault location, reduces the impact of system operation mode and transition resistance on the location result, and realizes rapid and accurate judgment of fault sections, providing a strong guarantee for the safe and stable operation of the distribution network.

[0110] This application provides an electronic device applicable to the above-described method for locating and detecting single-phase ground fault sections in a power distribution network, including:

[0111] Memory is used to protect computer programs and data;

[0112] A processor is used to run system programs.

[0113] This application provides a computer storage medium applicable to the above-mentioned distribution network single-phase ground fault section location and detection system, and performs hierarchical confidentiality management of the above-mentioned system and data in accordance with confidentiality management requirements.

[0114] Those skilled in the art will understand that embodiments of this application can be provided as a system or a computer program product. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0115] This application is described with reference to flowchart illustrations and / or block diagrams of devices (systems) and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0116] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0117] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0118] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0119] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0120] Computer-readable media include both permanent and non-permanent, removable and non-removable media, which can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0121] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0122] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for locating and detecting single-phase grounding fault sections in a power distribution network, characterized in that, Includes the following steps: Step 1: Data Acquisition: Obtain the magnetic field of each phase at each magnetic field sensor along each feeder. ,in, For the three phases of the feeder, k is the line number. Number the magnetic field sensor; Step 2: Obtain the zero-sequence magnetic field components: Calculate the zero-sequence components of the magnetic field of each phase of each feeder. ; Step 3: Magnetic field decomposition: Decompose the calculated zero-sequence magnetic field into the horizontal direction. and vertical direction ; Step 4: Extract the horizontal direction of the zero-sequence magnetic field of each magnetic field sensor on each feeder. The product is multiplied starting from the first magnetic field sensor on each feeder, and the cumulative product X is calculated. ln ; Step 5: Detection Criteria: During the detection process, we use the cumulative multiplication result X... ln The sign change is used to determine the faulty section.

2. The method for locating and detecting single-phase grounding fault sections in a distribution network as described in claim 1, characterized in that: The specific process of step 1 is as follows: Step 1.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance from each phase feeder to the installation location of the magnetic field sensor. ; Step 1.2: Obtain the phase magnetic field information of each magnetic field sensor on each feeder: In the formula, r is the vacuum permeability. j This represents the distance from each phase line to the installation location of the magnetic field sensor. This represents the current at each magnetic field sensor on each feeder.

3. The method for locating and detecting single-phase grounding fault sections in a distribution network as described in claim 1, characterized in that: The specific process of step 2 is as follows: Step 2: Calculate the zero-sequence component of each phase magnetic field of the magnetic field sensor on each feeder line using the symmetrical component method. : In the formula, The zero-sequence magnetic field of phase A is the first magnetic field sensor of line 1. The zero-sequence current calculation formula for phases B and C is the same as that for phase A.

4. The method for locating and detecting single-phase grounding fault sections in a distribution network as described in claim 1, characterized in that: The specific process of step 3 is as follows: Step 3.1: Based on the tower structure and the installation location of the magnetic field sensor, obtain the distance between each phase line and the magnetic field sensor. and the angle formed by each phase feeder and the sensor ; Step 3.2: Decompose the zero-sequence magnetic field vector into horizontal and vertical components: In the formula, and These are the horizontal and vertical components of the zero-sequence magnetic field vector decomposition, respectively. This refers to the angle formed between each phase feeder and the magnetic field sensor.

5. The method for locating and detecting single-phase grounding fault sections in a distribution network as described in claim 1, characterized in that: The specific process of step 4 is as follows: Step 4.1: Perform vector superposition of the zero-sequence magnetic field horizontal components of the magnetic field sensor: In the formula, These represent the horizontal components of the zero-sequence magnetic field for phases A, B, and C, respectively. This is the vector sum of the horizontal components of the zero-sequence magnetic field; Step 4.2: Define the direction sign function : Step 4.3: Perform a cumulative multiplication calculation on the first feeder line from the first magnetic field sensor to the nth magnetic field sensor, and record the cumulative multiplication result as X. ln : In the formula, l is the feeder number and n is the sensor number.

6. The method for locating and detecting single-phase grounding fault sections in a distribution network as described in claim 1, characterized in that: The specific criterion process for step 5 is as follows: If the cumulative product result X ln If the value of the first magnetic field sensor is negative, the fault section is directly determined to be between the first and second measuring points of the feeder. If the cumulative product result X ln If the value of the first magnetic field sensor is not negative, we continue to monitor the cumulative product of the subsequent sensors. When the cumulative product first becomes negative, we further observe the cumulative product of the subsequent sensors. If, starting from this negative value, the cumulative product results maintain the same sign for two or more consecutive times, then the faulty section is determined to be located between the measurement point where the last sign change occurred and the next measurement point.

7. A system for locating and detecting single-phase grounding fault sections in a power distribution network, characterized in that: The method for locating and detecting single-phase grounding fault sections in a distribution network according to any one of claims 1-6 includes: The data acquisition module is used to acquire the magnetic field of each phase at each magnetic field sensor on each feeder. ,in, The feeder consists of three phases, and k is the line number. Number the magnetic field sensor; The zero-sequence magnetic field component calculation module, connected to the data acquisition module, is used to calculate the zero-sequence component of the magnetic field of each phase of each feeder based on the acquired magnetic field information of each phase. ; The magnetic field decomposition module, connected to the zero-sequence magnetic field component calculation module, is used to decompose the calculated zero-sequence magnetic field into horizontal components. and vertical direction ; The zero-sequence magnetic field horizontal component processing module, connected to the magnetic field decomposition module, is used to extract the zero-sequence magnetic field horizontal component of each magnetic field sensor on each feeder. And perform vector superposition; The cumulative multiplication calculation module, connected to the zero-sequence magnetic field horizontal component processing module, is used to perform cumulative multiplication calculations on the zero-sequence magnetic field horizontal components, starting from the first magnetic field sensor of feeder 1, to obtain the cumulative multiplication result X. ln ; The fault criterion module, connected to the cumulative multiplication calculation module, is used to determine the fault based on the cumulative multiplication result X. ln The sign change determines the faulty section.

8. A processor, characterized in that: It is configured to perform the method for locating and detecting single-phase ground fault sections in a distribution network according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: It stores a computer program, which, when executed by a processor, implements the method for locating and detecting single-phase grounding fault sections in a power distribution network as described in any one of claims 1 to 6.

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