High-resistance grounding fault line selection method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to a high-resistance grounding fault line selection method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: collecting zero-sequence current of each line in the resonant grounding system in a preset time period when the resonant grounding system has a high-resistance grounding fault, accumulating the zero-sequence current of each line, correspondingly obtaining a zero-sequence current accumulation sequence of each line, and enhancing the current characteristic difference between a normal line and a fault line; and calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines, and according to the Kendall correlation coefficient between any two lines, accurately determining a fault line and reducing misjudgment.

Description

Technical Field

[0001] The present application relates to the technical field of line fault detection, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for selecting a high-resistance grounding fault line. Background Art

[0002] Arc suppression coils are typically installed between the neutral point of distribution network equipment and the ground. When a single-phase ground fault occurs, the inductive current flowing through the arc suppression coils and the capacitive fault current of the single-phase ground fault offset each other, compensating for the fault current. The residual current after compensation becomes very small, insufficient to sustain the arc, and thus extinguishes itself. However, while the arc suppression coils compensate for the fault current, they also introduce new problems: the difference in zero-sequence current between the faulty and non-faulty lines decreases, making fault line selection difficult. Summary of the Invention

[0003] Based on this, it is necessary to provide a high-resistance grounding fault line selection method, device, computer equipment, computer-readable storage medium and computer program product that can accurately identify the fault line in order to solve the above technical problems.

[0004] In a first aspect, the present application provides a method for selecting a high-resistance ground fault line, the method comprising:

[0005] collecting zero-sequence currents of various lines in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system;

[0006] Accumulate the zero-sequence current of each line respectively, and obtain the accumulated zero-sequence current sequence of each line;

[0007] Calculate the Kendall correlation coefficient between the cumulative series of zero-sequence currents of any two lines;

[0008] The fault line is determined based on the Kendall correlation coefficient between any two lines.

[0009] In one embodiment, the zero-sequence current accumulation sequence includes zero-sequence current accumulation data at multiple sampling moments; and the step of calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines includes:

[0010] For any two lines, the product of the accumulated changes of the two lines at any two sampling moments is determined based on the accumulated data pair of zero-sequence currents of the two lines at any two sampling moments;

[0011] Determining the number of consistent pairs and the number of divergent pairs of the two lines according to the product of the accumulated changes; a consistent pair indicates that the accumulated zero-sequence current data pairs of the two lines have a characteristic of changing in the same direction, and a divergent pair indicates that the accumulated zero-sequence current data pairs of the two lines have a characteristic of changing in opposite directions;

[0012] The Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines is calculated according to the number of the consistent pairs and the number of the disagreed pairs of the two lines.

[0013] In one embodiment, calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines based on the number of consistent pairs and the number of disagreed pairs of the two lines includes:

[0014] For the two lines, respectively obtain the number of repeated data of each line, where the number of repeated data is the number of zero-sequence current accumulated data with the same sampling time in the same zero-sequence current accumulated sequence;

[0015] The Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines is calculated according to the number of repeated data of each line, the number of consistent pairs and the number of inconsistent pairs of the two lines.

[0016] In one embodiment, calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines based on the number of repeated data of each line, the number of consistent pairs, and the number of inconsistent pairs of the two lines includes:

[0017] The Kendall correlation coefficient K between the cumulative zero-sequence current sequences of the two lines is calculated according to the following formula:

[0018]

[0019] in, represents the number of consistent pairs, represents the number of disagreement pairs, Indicates the number of repeated data in one of the two lines, Indicates the amount of repeated data in the other of the two lines.

[0020] In one embodiment, determining the faulty line based on the Kendall correlation coefficient between any two lines includes:

[0021] When the Kendall correlation coefficients between the target line and the remaining lines are all less than zero, determining that the target line is a fault line; the target line is a line in the resonant grounding system;

[0022] When the Kendall correlation coefficients between the lines are all greater than zero, it is determined that the busbar of the resonant grounding system is a fault line.

[0023] In one embodiment, before collecting the zero-sequence current of each line in the resonant grounding system, the method further includes:

[0024] collecting the neutral point voltage of the resonant grounding system;

[0025] Calculating an offset of the neutral point voltage according to the neutral point voltage and a preset rated voltage;

[0026] When the offset exceeds a preset voltage value, it is determined that a high-resistance grounding fault occurs in the resonant grounding system.

[0027] In a second aspect, the present application further provides a high-resistance ground fault line selection device, the device comprising:

[0028] A current acquisition module, configured to acquire zero-sequence current of each line in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system;

[0029] An accumulation module is used to accumulate the zero-sequence current of each line respectively, and obtain the zero-sequence current accumulation sequence of each line accordingly;

[0030] A correlation coefficient calculation module is used to calculate the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines;

[0031] The fault line selection module is used to determine the fault line based on the Kendall correlation coefficient between any two lines.

[0032] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the high-resistance grounding fault line selection method provided in any of the above embodiments is implemented.

[0033] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for selecting a high-resistance grounding fault line provided in any of the above embodiments is implemented.

[0034] In a fifth aspect, the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements the high-resistance grounding fault line selection method provided in any of the above embodiments.

[0035] In the above-mentioned high-resistance grounding fault line selection method, device, computer equipment, storage medium and program product, the zero-sequence current of each line in the resonant grounding system is collected within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system, the zero-sequence current of each line is accumulated separately, and the corresponding zero-sequence current accumulation sequence of each line is obtained, thereby enhancing the current characteristic difference between the normal line and the faulty line. Furthermore, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines is calculated. Based on the Kendall correlation coefficient between any two lines, the faulty line can be accurately determined and misjudgment can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 is a schematic diagram of a zero-sequence equivalent model when a ground fault occurs in a resonant grounding system in one embodiment;

[0038] Figure 2 1. A schematic flow chart of a method for selecting a line for a high-resistance ground fault according to an embodiment;

[0039] Figure 3 : is the accumulated zero-sequence current waveform of the fault line L1 and the non-fault line L2 in one embodiment;

[0040] Figure 4 1. A schematic diagram of a flow chart for calculating the Kendall correlation coefficient between the accumulated zero-sequence current sequences of any two lines in one embodiment;

[0041] Figure 5 Schematic diagram of the flow of a high-resistance ground fault line selection method in another embodiment;

[0042] Figure 6 This is a structural block diagram of a high-resistance ground fault line selection device in one embodiment;

[0043] Figure 7 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0045] A resonant grounding system is a power system whose neutral point is grounded through an arc suppression coil. When a high-resistance grounding fault occurs in a resonant grounding system, the effect of the equivalent inductance component in the line distributed parameters on the fault characteristics can be ignored due to the low transient resonant frequency. In addition, when a high-resistance grounding fault occurs, the system is mostly in an underdamped state, and the line resistance is much smaller than the transition resistance. Therefore, the effect of the line resistance on the fault characteristics can be ignored. Considering the distributed capacitance of each line to the ground and arc-extinguishing inductance L, the zero-sequence equivalent model of the resonant grounding system when a ground fault occurs is obtained as follows Figure 1 shown.

[0046] When a high-resistance ground fault occurs in line n, according to Kirchhoff's voltage law and the voltage-current relationship equation of the inductor, we have:

[0047]

[0048] in,

[0049]

[0050] Indicates virtual power supply at the fault point; Indicates the amplitude of the virtual power at the fault point; Indicates the frequency of virtual power at the fault point; Indicates the phase of the virtual power supply at the fault point; The zero-sequence resistance reflecting the transition resistance is approximately three times the transition resistance of the grounding point; Indicates the inductance value of the arc suppression coil; Represents the sum of the distributed capacitance of all lines to ground; Indicates bus zero-sequence voltage; Indicates the zero-sequence current flowing through the arc suppression coil.

[0051] According to formula-1, the second-order differential equation is constructed as:

[0052]

[0053] The characteristic roots of this second-order differential equation are:

[0054]

[0055] when When , the system is in an overdamped state, and the current flowing through the arc suppression coil is:

[0056]

[0057] in, 、 and are the damping coefficients respectively. Each parameter can be calculated by the following formula:

[0058]

[0059] in, Represents the equivalent impedance of the system.

[0060] The zero-sequence current of the kth normal route is:

[0061]

[0062] The zero-sequence current at the fault point is:

[0063]

[0064] The zero-sequence current at the fault line outlet is:

[0065]

[0066] According to Equations 7 to 9, it can be seen that when the system operates in an overdamped state, the zero-sequence current of each line is the superposition of the power frequency steady-state component and the attenuated DC component. Since the initial values ​​of the two DC components are not zero and the attenuation factor ( 、 ) are different, resulting in the free component persisting until it completely decays.

[0067] when When , the system operates in an underdamped state, and the current flowing through the arc suppression coil is:

[0068]

[0069] in,

[0070]

[0071] in, represents the attenuation factor, represents the free oscillation angular frequency.

[0072] It can be further obtained that the zero-sequence current of the kth normal line is:

[0073]

[0074] The zero-sequence current at the output after the nth line fault is:

[0075]

[0076] Observing Equations 12 and 13, when the system is in an underdamped state, the zero-sequence current is the superposition of the power frequency steady-state component and the attenuated AC component. At this time, the transient current amplitude is inversely proportional to the transition resistance, but the transient duration is prolonged as the transition resistance increases.

[0077] Because the zero-sequence current amplitudes of each line decay and their phases gradually converge when a high-resistance ground fault occurs, directly using the original current signal for fault line selection is prone to misjudgment. Based on this, this application provides a high-resistance ground fault line selection method that analyzes the accumulated zero-sequence current data of each line to enhance the current characteristic differences between normal and faulty lines, thereby improving the accuracy of fault line selection.

[0078] In one embodiment, Figure 2As shown, the high-resistance grounding fault line selection method includes steps 202 to 208.

[0079] Step 202 : within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system, collecting the zero-sequence current of each line in the resonant grounding system.

[0080] Exemplarily, the preset time period can be the first half-cycle after a high-resistance ground fault is determined to have occurred. A feeder terminal unit (FTU) is installed at the head end of each line in the resonant grounding system. The FTU can be used to collect zero-sequence current from each line. Exemplarily, the sampling frequency can be set to 10 kHz.

[0081] Step 204 : Accumulate the zero-sequence current of each line respectively, and obtain a corresponding zero-sequence current accumulation sequence of each line.

[0082] The zero-sequence current accumulation sequence includes zero-sequence current accumulation data at multiple sampling moments. For example, the zero-sequence current accumulation sequence of the i-th line can be expressed as:

[0083]

[0084] Where N represents the total number of data sampling moments, Indicates the accumulated zero-sequence current data at the jth sampling moment, 1≤j≤N, It can be expressed as:

[0085]

[0086] in, Represents the instantaneous value of the zero-sequence current of the i-th line.

[0087] Step 206 : Calculate the Kendall correlation coefficient between the accumulated zero-sequence current sequences of any two lines.

[0088] Step 208: Determine the faulty line based on the Kendall correlation coefficient between any two lines.

[0089] The zero-sequence current accumulation waveform obtained based on the known zero-sequence current accumulation sequence of the fault line L1 and the non-fault line L2 is as follows: Figure 3 As shown. Observe Figure 3During a high-resistance ground fault, the zero-sequence current waveforms of the faulty and non-faulty lines have weak amplitudes and similar phases, making them difficult to distinguish. Time-domain accumulation processing reveals that the zero-sequence current waveforms of the faulty and non-faulty lines have opposite polarity in the initial transient phase. Assuming the zero-sequence current flows from the busbar to the line as positive, the zero-sequence current waveform of the faulty line L1 exhibits a characteristic of flowing from the busbar to the line, while the zero-sequence current waveform of the non-faulty line L2 exhibits an inverse characteristic of flowing from the line to the busbar. The amplitude difference in the steady-state phase also increases significantly, significantly strengthening the fault signature. Therefore, the faulty line can be identified by analyzing the correlation between the zero-sequence current accumulation sequences of any two lines.

[0090] The Kendall correlation coefficient, a nonparametric statistic, can be used to assess the correlation between the zero-sequence current accumulation sequences of two lines by quantifying the rank correlation of the data sequences. If the Kendall correlation coefficient between the zero-sequence current accumulation sequences of two lines is negative, it indicates that the two zero-sequence current accumulation sequences are negatively correlated; if the Kendall correlation coefficient between the zero-sequence current accumulation sequences of two lines is positive, it indicates that the two zero-sequence current accumulation sequences are positively correlated; if the Kendall correlation coefficient between the zero-sequence current accumulation sequences of two lines is zero, it indicates that the two zero-sequence current accumulation sequences have no statistical correlation. Therefore, the Kendall correlation coefficient can be used to determine whether the polarity of the zero-sequence current accumulation sequences of any two lines is opposite at the initial stage of a fault, thereby identifying the faulty line.

[0091] In an embodiment of the present application, by collecting the zero-sequence current of each line in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system, the zero-sequence current of each line is accumulated separately, and the corresponding zero-sequence current accumulation sequence of each line is obtained, the current characteristic difference between the normal line and the faulty line is enhanced, and further, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines is calculated. Based on the Kendall correlation coefficient between any two lines, the faulty line can be accurately determined and the misjudgment can be reduced.

[0092] In one embodiment, Figure 4 As shown, the Kendall correlation coefficient between the accumulated zero-sequence current sequences of any two lines is calculated, including steps 402 to 406.

[0093] Step 402 : For any two lines, determine the product of the accumulated changes of the two lines at any two sampling moments based on the accumulated zero-sequence current data pairs of the two lines at any two sampling moments.

[0094] For example, the cumulative zero-sequence current sequence of any two lines can be simply expressed as , , where n represents the number of sampling moments, i.e., the sample size. Synchronously extract any two sampling moments from sequence A and sequence B, for example, the i-th sampling moment and the j-th sampling moment, and the zero-sequence current accumulated data pair is and , 1≤i≤j≤n, then the product of the accumulated changes of the two lines at any two sampling moments is .

[0095] Step 404: Determine the number of coincident pairs and divergent pairs of the two lines based on the product of the accumulated changes. A coincident pair indicates that the accumulated zero-sequence current data of the two lines change in the same direction, and a divergent pair indicates that the accumulated zero-sequence current data of the two lines change in opposite directions.

[0096] Specifically, if , indicating that the accumulated zero-sequence current data of the two lines show the same direction of change, that is, the zero-sequence current amplitudes of the two lines increase or decrease at the same time, which can be and It is judged as a consistent pair; if , indicating that the accumulated zero-sequence current data of the two lines show an inverse change characteristic, that is, when the zero-sequence current amplitude of one line increases in the positive direction, the zero-sequence current amplitude of the other line decreases in the negative direction. and Determined to be a divergent pair.

[0097] Step 406 : Calculate the Kendall correlation coefficient between the accumulated zero-sequence current sequences of the two lines based on the number of consistent pairs and the number of disagreed pairs of the two lines.

[0098] Specifically, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines can be calculated based on Equation 16:

[0099]

[0100] in, represents the number of consistent pairs, Indicates the number of disagreement pairs.

[0101] In this embodiment, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines can be calculated based on steps 402 to 406 to obtain the correlation of the zero-sequence current accumulation waveforms of each line, thereby determining the fault line.

[0102] In one embodiment, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines is calculated based on the number of consistent pairs and the number of divergent pairs of the two lines, including the steps of obtaining the number of repeated data for each line for each of the two lines, and calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines based on the number of repeated data for each line and the number of consistent pairs and the number of divergent pairs of the two lines.

[0103] The number of repeated data is the number of zero-sequence current accumulation data with the same sampling time in the same zero-sequence current accumulation sequence. Specifically, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of two lines can be calculated according to Formula 17:

[0104]

[0105] in, Indicates the number of repeated data in one of the two lines. Indicates the amount of duplicate data in the other of the two lines.

[0106] In this embodiment, considering that the zero-sequence current of each line may be repeatedly collected at certain sampling moments, the number of data at the same sampling moment in each zero-sequence current accumulation sequence is considered when calculating the Kendall correlation coefficient to ensure the accuracy of the calculated Kendall correlation coefficient.

[0107] Furthermore, in some embodiments, to simplify the analysis, as shown in Formula 18, only the positive and negative signs of the Kendall coefficient may be output, and the correlation of the zero-sequence current accumulation sequences of the two lines may be determined based on the positive and negative signs of the Kendall correlation coefficient.

[0108]

[0109] in, Used to indicate the sign of the Kendall correlation coefficient.

[0110] In a more specific embodiment, Figure 5 As shown, the high-resistance ground fault line selection method provided by the present application includes steps 502 to 516.

[0111] Step 502: Acquire the neutral point voltage of the resonant grounding system.

[0112] Step 504 : Calculate the offset of the neutral point voltage according to the neutral point voltage and the preset rated voltage.

[0113] The offset of the neutral point voltage may be a difference between the neutral point voltage and the rated voltage, or a ratio of the neutral point voltage to the rated voltage.

[0114] Step 506: When the offset exceeds the preset voltage value, it is determined that a high-resistance grounding fault occurs in the resonant grounding system.

[0115] Exemplarily, the preset voltage value may be 15% of the rated voltage.

[0116] Step 508 : within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system, collect the zero-sequence current of each line in the resonant grounding system.

[0117] Step 510 , accumulate the zero-sequence current of each line respectively, and obtain a corresponding zero-sequence current accumulation sequence of each line.

[0118] Step 512: Calculate the Kendall correlation coefficient between the accumulated zero-sequence current sequences of any two lines.

[0119] Steps 508 to 512 correspond to steps 202 to 206 one by one and are not described again here.

[0120] Step 514 : If the Kendall correlation coefficients between the target line and the remaining lines are all less than zero, the target line is determined to be a faulty line; the target line is a line in the resonant grounding system.

[0121] When a line fault occurs, the accumulated zero-sequence current waveforms of the faulty and non-faulty lines have opposite directions at the initial stage of the fault, while the amplitude and phase of the accumulated zero-sequence current waveform of the non-faulty line are essentially the same. Therefore, if the Kendall correlation coefficients between the target line and the remaining lines are all less than zero, the target line is determined to be the faulty line.

[0122] Step 516: When the Kendall correlation coefficients between the lines are all greater than zero, it is determined that the busbar of the resonant grounding system is a fault line.

[0123] When a busbar fault occurs, the amplitude and phase of the accumulated zero-sequence current waveforms of each line are essentially the same. Therefore, if the Kendall correlation coefficients between the lines are all greater than zero, the busbar in the resonant grounding system can be determined to be the fault line.

[0124] In this embodiment, by collecting the zero-sequence current of each line in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system, the zero-sequence current of each line is accumulated respectively, and the corresponding zero-sequence current accumulation sequence of each line is obtained, the current characteristic difference between the normal line and the fault line is enhanced. Furthermore, the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines is calculated, and when the Kendall correlation coefficients between the target line and the remaining lines are all less than zero, the target line is determined to be the fault line. When the Kendall correlation coefficients between the lines are all greater than zero, the busbar of the resonant grounding system is determined to be the fault line. This can accurately identify the fault line and reduce misjudgment.

[0125] It should be understood that, although the various steps in the flowcharts involved in the above embodiments are shown in the order shown, these steps are not necessarily performed in this order. Unless otherwise specified, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.

[0126] Based on the same inventive concept, embodiments of the present application also provide a high-resistance ground fault line selection device for implementing the high-resistance ground fault line selection method described above. The solution provided by this device is similar to the solution described in the above-mentioned method. Therefore, the specific limitations of one or more embodiments of the high-resistance ground fault line selection device provided below can be found in the above-mentioned limitations of the high-resistance ground fault line selection method and will not be further elaborated here.

[0127] In an exemplary embodiment, Figure 6 As shown, a high-resistance ground fault line selection device is provided, comprising: a current acquisition module 602, an accumulation module 604, a correlation coefficient calculation module 606 and a fault line selection module 608, wherein:

[0128] The current acquisition module 602 is used to collect the zero-sequence current of each line in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system;

[0129] The accumulation module 604 is used to accumulate the zero-sequence current of each line respectively, and obtain the zero-sequence current accumulation sequence of each line;

[0130] The correlation coefficient calculation module 606 is used to calculate the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines;

[0131] The fault line selection module 608 is used to determine the fault line according to the Kendall correlation coefficient between any two lines.

[0132] In one embodiment, the correlation coefficient calculation module is further configured to determine, for any two lines, a product of accumulated changes of the two lines at any two sampling moments based on a pair of accumulated zero-sequence current data of the two lines at any two sampling moments;

[0133] The number of consistent pairs and divergent pairs of the two lines is determined based on the product of the accumulated changes; consistent pairs indicate that the accumulated zero-sequence current data of the two lines change in the same direction, and divergent pairs indicate that the accumulated zero-sequence current data of the two lines change in opposite directions;

[0134] According to the number of consistent pairs and the number of disagreement pairs of the two lines, the Kendall correlation coefficient between the cumulative series of zero-sequence currents of the two lines is calculated.

[0135] In one embodiment, the correlation coefficient calculation module is further configured to obtain the number of repeated data of each line for each of the two lines, where the number of repeated data is the number of zero-sequence current accumulated data with the same sampling time in the same zero-sequence current accumulated sequence;

[0136] The Kendall correlation coefficient between the accumulated zero-sequence current sequences of the two lines is calculated based on the number of repeated data of each line, the number of consistent pairs, and the number of disagreement pairs of the two lines.

[0137] In one embodiment, the correlation coefficient calculation module is further configured to calculate the Kendall correlation coefficient K between the accumulated zero-sequence current sequences of the two lines according to Equation 17.

[0138] In one embodiment, the fault line selection module is further configured to determine that the target line is a fault line when the Kendall correlation coefficients between the target line and the remaining lines are all less than zero; the target line is a line in the resonant grounding system;

[0139] When the Kendall correlation coefficients between all lines are greater than zero, the busbar of the resonant grounding system is determined to be the fault line.

[0140] In one embodiment, the high-resistance grounding fault line selection device further includes a fault detection module for collecting the neutral point voltage of the resonant grounding system;

[0141] Calculate the offset of the neutral point voltage according to the neutral point voltage and the preset rated voltage;

[0142] When the offset exceeds a preset voltage value, it is determined that a high-resistance grounding fault occurs in the resonant grounding system.

[0143] Each module in the high-resistance ground fault line selection device described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0144] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 7 As shown. The computer device includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via wired or wireless means, and the wireless means can be implemented via Wi-Fi, mobile cellular networks, near-field communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for selecting a high-resistance ground fault line. The display unit of the computer device is used to produce a visual image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

[0145] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0146] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the high-resistance grounding fault line selection method provided in any of the above embodiments when executing the computer program.

[0147] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the high-resistance grounding fault line selection method provided in any of the above embodiments is implemented.

[0148] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the method for selecting a high-resistance grounding fault line provided in any of the above embodiments is implemented.

[0149] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0150] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0151] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A high-resistance ground fault line selection method, characterized in that: The method comprises: collecting zero-sequence currents of various lines in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system; Accumulate the zero-sequence current of each line respectively, and obtain the accumulated zero-sequence current sequence of each line; Calculate the Kendall correlation coefficient between the cumulative series of zero-sequence currents of any two lines; The fault line is determined based on the Kendall correlation coefficient between any two lines.

2. The method according to claim 1, characterized in that The zero-sequence current accumulation sequence includes zero-sequence current accumulation data at multiple sampling moments; the calculation of the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines includes: For any two lines, the product of the accumulated changes of the two lines at any two sampling moments is determined based on the accumulated data pair of zero-sequence currents of the two lines at any two sampling moments; Determining the number of consistent pairs and the number of divergent pairs of the two lines according to the product of the accumulated changes; a consistent pair indicates that the accumulated zero-sequence current data pairs of the two lines have a characteristic of changing in the same direction, and a divergent pair indicates that the accumulated zero-sequence current data pairs of the two lines have a characteristic of changing in opposite directions; The Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines is calculated according to the number of the consistent pairs and the number of the disagreed pairs of the two lines.

3. The method according to claim 2, characterized in that Calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines according to the number of consistent pairs and the number of divergent pairs of the two lines includes: For the two lines, respectively obtain the number of repeated data of each line, where the number of repeated data is the number of zero-sequence current accumulated data with the same sampling time in the same zero-sequence current accumulated sequence; The Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines is calculated according to the number of repeated data of each line, the number of consistent pairs and the number of inconsistent pairs of the two lines.

4. The method according to claim 3, characterized in that Calculating the Kendall correlation coefficient between the zero-sequence current accumulation sequences of the two lines based on the number of repeated data of each line, the number of consistent pairs, and the number of divergent pairs of the two lines includes: The Kendall correlation coefficient K between the cumulative zero-sequence current sequences of the two lines is calculated according to the following formula: in, represents the number of consistent pairs, represents the number of disagreement pairs, Indicates the number of repeated data in one of the two lines, Indicates the amount of repeated data in the other of the two lines.

5. The method according to any one of claims 1 to 4, characterized in that The method of determining the fault line according to the Kendall correlation coefficient between any two lines includes: When the Kendall correlation coefficients between the target line and the remaining lines are all less than zero, determining that the target line is a fault line; the target line is a line in the resonant grounding system; When the Kendall correlation coefficients between the lines are all greater than zero, it is determined that the busbar of the resonant grounding system is a fault line.

6. The method according to any one of claims 1 to 4, characterized in that: Before collecting the zero-sequence current of each line in the resonant grounding system, the method further includes: collecting the neutral point voltage of the resonant grounding system; Calculating an offset of the neutral point voltage according to the neutral point voltage and a preset rated voltage; When the offset exceeds a preset voltage value, it is determined that a high-resistance grounding fault occurs in the resonant grounding system.

7. A high-resistance ground fault line selection device, characterized in that: The device comprises: A current acquisition module, configured to acquire zero-sequence current of each line in the resonant grounding system within a preset time period when a high-resistance grounding fault occurs in the resonant grounding system; An accumulation module is used to accumulate the zero-sequence current of each line respectively, and obtain the zero-sequence current accumulation sequence of each line accordingly; A correlation coefficient calculation module is used to calculate the Kendall correlation coefficient between the zero-sequence current accumulation sequences of any two lines; The fault line selection module is used to determine the fault line based on the Kendall correlation coefficient between any two lines.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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