Line fault determination method and device, computer device and storage medium

Abstract

This application relates to a method, apparatus, computer equipment, and storage medium for line fault identification. The method includes: acquiring the first zero-sequence current and the first three-phase voltage at a first relay protection device on the energy side, and the second zero-sequence current and the second three-phase voltage at a second relay protection device on the power system side; using the first relay protection device whose first zero-sequence current and first three-phase voltage meet the conditions for a first outgoing ground fault as a target fault reference point, and using the second relay protection device whose second zero-sequence current and second three-phase voltage meet the conditions for a second outgoing ground fault as a target fault reference point; calculating the zero-sequence voltage calculation value and acquiring the zero-sequence voltage measurement value at the target fault reference point, and calculating the zero-sequence voltage similarity between the calculated and measured values; determining the target fault location based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold. This method can improve the accuracy of fault identification for new energy transmission lines.

Description

Technical Field

[0001] This application relates to the field of electrical technology, and in particular to a method, apparatus, computer equipment, and storage medium for determining line faults. Background Technology

[0002] Because the fault characteristics of the power grid corresponding to the access of new energy power generation such as wind and solar power to the power system are quite different from those of the power grid that uses conventional power sources as the main power supply, the traditional power grid relay protection is affected by the fault current characteristics of new energy, resulting in a decrease in the accuracy of fault direction determination of new energy transmission lines. Summary of the Invention

[0003] Based on this, it is necessary to provide a method, device, computer equipment, and storage medium for identifying faults in new energy transmission lines between new energy sources and the power system, thereby improving the accuracy of fault identification in new energy transmission lines.

[0004] A method for determining line faults, the method comprising:

[0005] The first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side are respectively obtained;

[0006] If the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition, then the second relay protection device is taken as the target fault reference point.

[0007] Calculate the zero-sequence voltage value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0008] Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined.

[0009] In one embodiment, the first outlet ground fault condition includes the first zero-sequence current being greater than the first preset current and the first three-phase voltage being less than the first preset voltage; the second outlet ground fault condition includes the second zero-sequence current being greater than the second preset current and the second three-phase voltage being less than the second preset voltage.

[0010] In one embodiment, calculating the zero-sequence voltage value corresponding to the target fault reference point includes:

[0011] When the target fault reference point is at the first relay protection device, the current measurement value of the first zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance of the line corresponding to the sending line, and the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are obtained.

[0012] The zero-sequence current measurement value corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance of the sending line, and the zero-sequence resistance and zero-sequence inductance of the power system side are fused together to obtain the zero-sequence voltage calculation value corresponding to the target fault reference point.

[0013] In one embodiment, the method further includes:

[0014] When the target fault reference point is at the second relay protection device, the current measurement value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are obtained.

[0015] The measured value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are fused to obtain the calculated value of the zero-sequence voltage corresponding to the target fault reference point.

[0016] In one embodiment, determining the target fault location corresponding to the target fault reference point based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point includes:

[0017] If the target fault reference point is at the first relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the first relay protection device.

[0018] When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the first relay protection device.

[0019] In one embodiment, the method further includes:

[0020] If the target fault reference point is at the second relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the second relay protection device.

[0021] When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the second relay protection device.

[0022] In one embodiment, the calculated value of the zero-sequence voltage corresponding to the target fault reference point and the measured value of the zero-sequence voltage are fused to obtain the zero-sequence voltage similarity corresponding to the target fault reference point, including:

[0023] Obtain the average measured voltage value corresponding to the zero-sequence voltage measurement value within a data window and the average calculated voltage value corresponding to the zero-sequence voltage calculation value within a data window;

[0024] The zero-sequence voltage similarity is obtained by fusing the calculated zero-sequence voltage value, the measured zero-sequence voltage value, the average value of the measured voltage, and the average value of the calculated voltage.

[0025] A line fault detection device, the device comprising:

[0026] The acquisition module is used to acquire the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side.

[0027] The judgment module is used to determine the first relay protection device as the target fault reference point if the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, and the second relay protection device as the target fault reference point if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition.

[0028] The calculation module is used to calculate the zero-sequence voltage calculation value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0029] The determination module is used to determine the target fault location corresponding to the target fault reference point based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point.

[0030] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps:

[0031] The first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side are respectively obtained;

[0032] If the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition, then the second relay protection device is taken as the target fault reference point.

[0033] Calculate the zero-sequence voltage value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0034] Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined.

[0035] A computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0036] The first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side are respectively obtained;

[0037] If the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition, then the second relay protection device is taken as the target fault reference point.

[0038] Calculate the zero-sequence voltage value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0039] Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined.

[0040] The aforementioned line fault identification method, device, computer equipment, and storage medium acquire, respectively, the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side; if the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition, then the second relay protection device is taken as the target fault reference point; calculate the zero-sequence voltage calculation value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point; Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined, realizing the judgment of the grounding fault at the outlet of the preset energy transmission line. It makes good use of the characteristic that when the preset energy side protection is reverse fault or the power system side is positive fault, the current measured at the corresponding second relay protection device is the fault current provided by the power system side. The theoretical zero-sequence voltage calculation value is compared with the preset zero-sequence voltage similarity threshold to distinguish the target fault location corresponding to the first relay protection device or the second relay protection device of the transmission line. This avoids the influence of the preset energy being unsuitable for the power supply fault characteristics of judging line faults based on positive sequence voltage, making the speed of judging the transmission line fault between the preset energy and the power system faster, while improving the accuracy of the preset energy transmission line fault judgment. Attached Figure Description

[0041] Figure 1 This is an application environment diagram of the line fault detection method in one embodiment;

[0042] Figure 2 This is a flowchart illustrating a line fault detection method in one embodiment;

[0043] Figure 3 This is a flowchart illustrating the zero-sequence voltage calculation in one embodiment;

[0044] Figure 4 This is a flowchart illustrating the zero-sequence voltage calculation in another embodiment;

[0045] Figure 5 This is a flowchart illustrating the similarity calculation process in one embodiment;

[0046] Figure 6 This is a flowchart illustrating the fault diagnosis process in one embodiment;

[0047] Figure 7 This is a flowchart illustrating the fault diagnosis process in another embodiment;

[0048] Figure 8 This is a structural diagram of the component relationships in one embodiment;

[0049] Figure 9 This is a flowchart of the overall process for determining line faults in one embodiment;

[0050] Figure 10 This is a structural block diagram of a line fault detection device in one embodiment;

[0051] Figure 11 This is an internal structural diagram of a computer device in one embodiment;

[0052] Figure 12 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] The line fault identification method provided in this application embodiment can be applied to, for example, Figure 1In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104, or it can be located in the cloud or on another network server. Both terminal 102 and server 104 can be used to acquire the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side. If the first zero-sequence current and the first three-phase voltage meet the first outlet ground fault condition, the first relay protection device is used as the target fault reference point. If the second zero-sequence current and the second three-phase voltage meet the second outlet ground fault condition, the second relay protection device is used as the target fault reference point. The zero-sequence voltage calculation value corresponding to the target fault reference point is calculated, and the zero-sequence voltage measurement value corresponding to the target fault reference point is obtained. The zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point are fused to obtain the zero-sequence voltage similarity corresponding to the target fault reference point. Based on the judgment result of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined. The terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle systems. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0055] In one embodiment, such as Figure 2 As shown, a line fault detection method is provided, which is applied to... Figure 1 Taking a terminal or server as an example, the following steps are included:

[0056] Step S200: Obtain the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side.

[0057] Among them, "preset energy" refers to the pre-set new energy source, which can change according to the definition of new energy in the era, such as wind and solar energy. "First relay protection device location" refers to the area corresponding to the relay protection device installed at the output of the transmission line on the preset energy side. "First zero-sequence current" refers to the zero-sequence current at the first relay protection device. "First three-phase voltage" refers to the three-phase voltage at the first relay protection device. AC transmission systems are three-phase, each phase has its corresponding voltage, and the three phases are staggered by 120°, namely phase A, phase B, and phase C. "Second relay protection device location" refers to the area corresponding to the relay protection device installed at the output of the transmission line on the power system side. "Second three-phase voltage" refers to the three-phase voltage at the first relay protection device. "Output" is the location near the relay protection device.

[0058] Specifically, on the transmission lines between the preset energy source and the power system, relay protection devices are installed at the outlets of the transmission lines on both the preset energy side and the power system side. The area corresponding to the relay protection device on the preset energy side is designated as the first relay protection device location, and the area corresponding to the relay protection device on the power system side is designated as the second relay protection device location. Both the first and second relay protection devices have corresponding zero-sequence currents and zero-sequence voltages. Obtaining the first zero-sequence current and first three-phase voltage corresponding to the first relay protection device location, as well as the second zero-sequence current and second three-phase voltage corresponding to the second relay protection device location, provides a data basis for subsequently determining the fault locations corresponding to the first and second relay protection devices simultaneously.

[0059] Step S202: If the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault conditions, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault conditions, then the second relay protection device is taken as the target fault reference point.

[0060] The first ground fault condition refers to whether the first zero-sequence current and the first three-phase voltage at the first relay protection device meet the conditions for a ground fault. The first relay protection device meets the ground fault condition when the corresponding first zero-sequence current is greater than a preset percentage of the current during normal operation, and the first three-phase voltage is less than a preset percentage of the voltage during normal operation. The second ground fault condition refers to whether the second zero-sequence current and the second three-phase voltage at the second relay protection device meet the conditions for a ground fault. The second relay protection device meets the ground fault condition when the corresponding second zero-sequence current is greater than a preset percentage of the current during normal operation, and the second three-phase voltage is less than a preset percentage of the voltage during normal operation. The target fault reference point refers to the relay protection device where a ground fault exists. The directions for determining the ground fault point are different for the first and second relay protection devices.

[0061] Specifically, only one of the first and second relay protection devices can have an output grounding fault. That is, when the first relay protection device is found to meet the first output grounding fault condition, the second relay protection device must not meet the second output grounding fault condition, and vice versa. When the second relay protection device meets the second output grounding fault condition, the first relay protection device must not meet the first output grounding fault condition. The corresponding target fault reference point is the relay protection device that meets the corresponding output grounding fault condition.

[0062] Step S204: Calculate the zero-sequence voltage calculation value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0063] Among them, the zero-sequence voltage calculation value refers to the theoretical value of the zero-sequence voltage corresponding to the target fault reference point, which is calculated by a preset principle formula. The principle formulas for calculating the zero-sequence voltage corresponding to the first relay protection device and the second relay protection device are different, as can be seen in formulas (3) and (4). The zero-sequence voltage measurement value refers to the zero-sequence voltage corresponding to the target fault reference point currently measured. The zero-sequence voltage similarity refers to the similarity between the zero-sequence voltage calculation value and the zero-sequence voltage measurement value, which can be used as a basis for judging whether the direction of the grounding fault at the outlet is at the forward fault location or the reverse fault location at the target fault reference point.

[0064] Specifically, the formula for calculating the theoretical value of zero-sequence voltage is different when the target fault reference point is at the first relay protection device and when it is at the second relay protection device. The similarity between the calculated value and the measured value of zero-sequence voltage can reflect the direction of the outlet grounding fault. By calculating the zero-sequence voltage similarity between the calculated value and the measured value of zero-sequence voltage at the target fault reference point, a data basis can be provided for subsequent determination of the direction of the outlet grounding fault corresponding to the target fault reference point.

[0065] Step S206: Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, determine the target fault location corresponding to the target fault reference point.

[0066] The zero-sequence voltage similarity threshold is a threshold used to determine whether the fault corresponding to the target fault reference point is a forward fault or a reverse fault. The target fault location refers to the place where an outlet grounding fault exists.

[0067] Specifically, the direction for determining the target fault location differs when the target fault reference point is at the first relay protection device and the second relay protection device. When the target fault reference point is at the first relay protection device, if the zero-sequence voltage similarity corresponding to the first relay protection device is greater than the zero-sequence voltage similarity threshold, it indicates that the target fault is located at the reverse fault location corresponding to the first relay protection device, that is, on the side of the first relay protection device closer to the preset energy side. If the zero-sequence voltage similarity corresponding to the first relay protection device is less than the zero-sequence voltage similarity threshold, it indicates that the target fault is located at the forward fault location corresponding to the first relay protection device. The first fault reference point is the side of the first relay protection device that is furthest from the preset energy side. Conversely, when the target fault reference point is the second relay protection device, if the zero-sequence voltage similarity corresponding to the second relay protection device is greater than the zero-sequence voltage similarity threshold, it indicates that the target fault is located at the forward fault location corresponding to the second relay protection device, which is the side of the second relay protection device that is furthest from the power system side. If the zero-sequence voltage similarity corresponding to the second relay protection device is less than the zero-sequence voltage similarity threshold, it indicates that the target fault is located at the reverse fault location corresponding to the second relay protection device, which is the side of the second relay protection device that is closer to the preset energy side.

[0068] In the aforementioned line fault identification method, the first zero-sequence current and first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and second three-phase voltage at the second relay protection device corresponding to the power system side are obtained respectively. If the first zero-sequence current and first three-phase voltage meet the first outlet grounding fault condition, the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and second three-phase voltage meet the second outlet grounding fault condition, the second relay protection device is taken as the target fault reference point. The zero-sequence voltage calculation value corresponding to the target fault reference point is calculated, and the zero-sequence voltage measurement value corresponding to the target fault reference point is obtained. The zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point are fused to obtain the zero-sequence voltage similarity corresponding to the target fault reference point. Based on the target fault reference... The judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the test point determine the target fault location corresponding to the target fault reference point, realizing the judgment of the grounding fault at the outlet of the preset energy transmission line. It makes good use of the characteristic that when the preset energy side protection is reverse fault or the power system side is positive fault, the current measured at the corresponding second relay protection device is the fault current provided by the power system side. The theoretical zero-sequence voltage calculation value is compared with the preset zero-sequence voltage similarity threshold to distinguish the target fault location corresponding to the first relay protection device or the second relay protection device of the transmission line. This avoids the influence of the preset energy being unsuitable for the power supply fault characteristics of judging line faults based on positive sequence voltage, making the speed of judging the transmission line fault between the preset energy and the power system faster, while improving the accuracy of the preset energy transmission line fault judgment.

[0069] In one embodiment, the first outlet grounding fault condition includes the first zero-sequence current being greater than the first preset current and the first three-phase voltage being less than the first preset voltage; the second outlet grounding fault condition includes the second zero-sequence current being greater than the second preset current and the second three-phase voltage being less than the second preset voltage.

[0070] Wherein, the first preset current refers to a preset percentage of the current at the first relay during normal operation. The first preset voltage refers to a preset percentage of the voltage at the first relay during normal operation. The second preset current refers to a preset percentage of the current at the second relay during normal operation. The second preset voltage refers to a preset percentage of the voltage at the second relay during normal operation. For example, if the current and voltage at the first relay during normal operation are I1 and U1 respectively, and the current and voltage at the second relay during normal operation are I2 and U2 respectively, then the first preset current is 10%I1, the first preset voltage is 10%U2, the second current is 10%I2, and the second preset voltage is 10%U2.

[0071] Specifically, the judgment principle for determining whether an outlet grounding fault exists at the first relay and the second relay is the same, but the data used for judgment is different. The judgment principle can be shown in formulas (1) and (2), where I0 is the zero-sequence current amplitude at the relay protection device, i.e., the first zero-sequence current corresponding to the first relay protection device or the second zero-sequence current corresponding to the second relay protection device; I set(0) This refers to the zero-sequence current threshold for ground faults at the corresponding relay protection device, i.e., the first preset current at the first relay protection device or the second preset current at the second relay protection device; U & U represents any one of the three-phase voltages at the relay protection device, where U = phase A, B, or C, i.e., the first three-phase voltage at the first relay protection device or the second three-phase voltage at the second relay protection device; low This refers to the low voltage threshold corresponding to the relay protection device, namely the first preset voltage corresponding to the first relay protection device or the second preset voltage corresponding to the second relay protection device.

[0072] I0>I set(0) (1)

[0073] U & low (2)

[0074] In one embodiment, such as Figure 3 As shown, step S204 includes:

[0075] Step S300: When the target fault reference point is at the first relay protection device, obtain the first zero-sequence current measurement value corresponding to the target fault reference point, the line zero-sequence resistance and line zero-sequence inductance corresponding to the sending line, and the zero-sequence resistance and zero-sequence inductance corresponding to the power system side.

[0076] Step S302: The measured value of the first zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance of the sending line, and the zero-sequence resistance and zero-sequence inductance of the power system side are fused to obtain the calculated value of the zero-sequence voltage corresponding to the target fault reference point.

[0077] The first zero-sequence current measurement value refers to the zero-sequence current value corresponding to the first relay device currently measured. Zero-sequence resistance refers to the resistance value through which the zero-sequence current passes in the three-phase circuit. Zero-sequence inductance refers to the inductance value corresponding to the zero-sequence current.

[0078] Specifically, the formulas for calculating the zero-sequence voltage at the first and second relay protection devices are different, as detailed below. Figure 8 The fault diagnosis of the transmission line between the new energy power source and the power grid (i.e., the power system) is described, in which...​ Figure 8 In this equation, P represents the location of the first relay protection device. The zero-sequence voltage at the location of the first relay protection device can be calculated using formula (3). In formula (3)... This is the calculated value of the instantaneous zero-sequence voltage of the first relay protection device P, that is, the calculated value of the zero-sequence voltage corresponding to the first relay protection device. The zero-sequence resistance of the line; The measured value of the first zero-sequence current corresponding to the first relay protection device P; This is the zero-sequence inductance of the line; To protect the zero-sequence resistance of the power grid behind N, i.e. the zero-sequence resistance on the power system side; To protect the zero-sequence inductance of the power grid behind N, i.e. the zero-sequence inductance on the power system side.

[0079]

[0080] In this embodiment, by acquiring the current zero-sequence current measurement value at the first relay protection device, the zero-sequence resistance and inductance of the sending line, and the zero-sequence resistance and inductance on the power system side, the zero-sequence current measurement value at the first relay protection device, the zero-sequence resistance and inductance of the sending line, and the zero-sequence resistance and inductance on the power system side are fused to obtain the zero-sequence voltage calculation value at the first relay protection device. Considering the characteristics of the first relay protection device on the preset energy side, the corresponding zero-sequence voltage calculation value is calculated using the corresponding principle formula, which to a certain extent ensures the accuracy of subsequent calculation of zero-sequence voltage similarity to determine the target fault location at the first relay protection device.

[0081] In one embodiment, such as Figure 4 As shown, step S204 includes:

[0082] Step S400: When the target fault reference point is at the second relay protection device, obtain the current measurement value of the second zero-sequence current, the zero-sequence resistance and zero-sequence inductance corresponding to the target fault reference point, and the corresponding zero-sequence resistance and zero-sequence inductance on the power system side.

[0083] Step S402: The measured value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are fused to obtain the calculated value of the zero-sequence voltage corresponding to the target fault reference point.

[0084] The second zero-sequence current measurement value refers to the zero-sequence current value corresponding to the second relay device currently measured.

[0085] Specifically, when it is determined that the grounding fault at the outlet is located near the second relay protection device, the calculated value of the zero-sequence voltage corresponding to the second relay protection device can be calculated first. This is the theoretical value of the zero-sequence voltage corresponding to the second relay protection device. Specifically, it can be done as follows: Figure 8 The fault diagnosis of the transmission line between the new energy power source and the power grid (i.e., the power system) is described, in which... Figure 8 Q represents the location of the second relay protection device. The zero-sequence voltage at the location of the second relay protection device can be calculated using formula (4). In formula (4) This is the calculated value of the instantaneous zero-sequence voltage of the second relay protection device Q, that is, the calculated value of the zero-sequence voltage at the second relay protection device. To protect the zero-sequence resistance of the power grid behind N, i.e. the zero-sequence resistance on the power system side; This is the measured value of the second zero-sequence current corresponding to the second relay protection device Q; To protect the zero-sequence inductance of the power grid behind N, i.e. the zero-sequence inductance on the power system side.

[0086]

[0087] In this embodiment, by acquiring the current measurement value of the second zero-sequence current at the second relay protection device and the corresponding zero-sequence resistance and zero-sequence inductance on the power system side, the current measurement value of the second zero-sequence current at the second relay protection device and the corresponding zero-sequence resistance and zero-sequence inductance on the power system side are fused to obtain the zero-sequence voltage calculation value corresponding to the target fault reference point. Considering the characteristics of the second relay protection device on the power system side, the corresponding zero-sequence voltage calculation value is calculated using the corresponding principle formula, which to a certain extent ensures the accuracy of subsequent calculation of zero-sequence voltage similarity to determine the target fault location corresponding to the second relay protection device.

[0088] In one embodiment, such as Figure 5 As shown, step S204 includes:

[0089] Step S500: Obtain the average value of the measured voltage corresponding to the zero-sequence voltage measurement value within a data window and the average value of the calculated voltage corresponding to the zero-sequence voltage calculation value within a data window.

[0090] Step S502: The calculated value of zero-sequence voltage, the measured value of zero-sequence voltage, the average value of the measured voltage, and the average value of the calculated voltage are fused to obtain the zero-sequence voltage similarity.

[0091] The measured voltage average refers to the average of the zero-sequence voltage measurements obtained within a data window. The calculated voltage average refers to the average of the calculated zero-sequence voltage values ​​within a data window.

[0092] Specifically, the principle formula for calculating the zero-sequence voltage similarity at the first and second relay protection devices is the same. For example, taking P at the first relay protection device as an example, the specific principle formula can be found in formulas (5) and (6). In formulas (5) and (6), The zero-sequence voltage measurement is a sampled value at time i. is the sampled value of the zero-sequence voltage at time i; Num is the length of a data window; for The average value within a data window, i.e., the average measured voltage; for The average value within a data window is used to calculate the average voltage. For Q at the second relay device, the principle formulas (5) and (6) can also be used to calculate the zero-sequence voltage similarity at the second relay protection device. However, the corresponding calculation data requires the data corresponding to the second relay protection device. Since the outlet grounding fault is either near the first relay protection device or near the second relay protection device, the calculation of the zero-sequence voltage similarity is only performed after the target fault reference point is determined, and the calculated zero-sequence voltage similarity is used in the subsequent steps of judging the target fault location.

[0093]

[0094]

[0095] In this embodiment, by obtaining the average measured voltage value corresponding to the zero-sequence voltage measurement value within a data window and the average calculated voltage value corresponding to the zero-sequence voltage calculation value within a data window, the zero-sequence voltage calculation value, the zero-sequence voltage measurement value, the average measured voltage value, and the average calculated voltage value are fused to obtain the zero-sequence voltage similarity. This completes the calculation of the similarity relationship between the zero-sequence voltage measurement value and the zero-sequence voltage calculation value, providing data basis for the final judgment of the target fault location. At the same time, the calculation of its principle characteristics also ensures the accuracy of the judgment of the target fault location.

[0096] In one embodiment, such as Figure 6 As shown, step S206 includes:

[0097] Step S600: If the target fault reference point is at the first relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the first relay protection device.

[0098] Step S602: When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the first relay protection device.

[0099] Specifically, the location of the target fault determined by the first relay protection device and the second relay protection device is different. For example... Figure 8 Describe it with examples, such as Figure 8 In this diagram, P represents the location of the first relay protection device, F1 and F2 represent the reverse and forward fault points near P, respectively, and Q represents the location of the second relay protection device. F3 and F4 represent the forward and reverse fault points near Q, respectively, and the target fault location will appear at one of F1, F2, F3, or F4. When the target fault location is P of the first relay protection device, if the zero-sequence voltage similarity corresponding to P of the first relay protection device is greater than the zero-sequence voltage similarity threshold, then the target fault location is the reverse fault location corresponding to P of the first relay protection device. Figure 8 The reverse output fault point F1 corresponds to point P in the diagram; if the zero-sequence voltage similarity corresponding to point P at the first relay protection device is less than or equal to the zero-sequence voltage similarity threshold, then it indicates that the target fault location is the forward fault location corresponding to point P at the first relay protection device, i.e. Figure 8 The positive exit fault point F2 corresponds to point P in the diagram.

[0100] In this embodiment, if the target fault reference point is at the first relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the first relay protection device; when the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the forward fault location corresponding to the first relay protection device. This targeted application of the characteristic that the first relay protection device is located on the preset energy side ensures the accuracy of the final fault point determination.

[0101] In one embodiment, such as Figure 7 As shown, step S206 includes:

[0102] Step S700: If the target fault reference point is at the second relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the second relay protection device.

[0103] Step S702: When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the second relay protection device.

[0104] Specifically, due to the location of the second relay protection device on the power system side, and the differences in principles such as the electrical characteristics between the preset energy side and the power system side, the direction in which the second relay protection device determines the ground fault point is exactly the opposite of that of the first relay protection device. This can be explained as follows: Figure 8 The example shown is used for description. For example... Figure 8 In the diagram, Q represents the location of the second relay protection device. F3 and F4 represent the forward and reverse fault points near Q of the second relay protection device, respectively. If the target fault reference point is Q of the second relay protection device, then when the zero-sequence voltage similarity corresponding to Q of the second relay protection device is greater than the zero-sequence voltage similarity threshold, it indicates that the target fault location is the forward fault location corresponding to Q of the second relay protection device. Figure 8 The forward fault point F3 corresponds to point Q in the second relay protection device; if the zero-sequence voltage similarity corresponding to Q in the second relay protection device is less than or equal to the zero-sequence voltage similarity threshold, then it indicates that the target fault point is the reverse fault point corresponding to Q in the second relay protection device, i.e. Figure 8 The reverse exit fault point F4 corresponds to point Q in the diagram.

[0105] In this embodiment, if the target fault reference point is at the second relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the forward fault location corresponding to the second relay protection device; when the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the second relay protection device. This targeted application of the characteristic of the second relay protection device being located on the power system side ensures the accuracy of the final fault point determination.

[0106] In one embodiment, the comparison between zero-sequence voltage similarity and zero-sequence voltage similarity threshold is based on formula (7), where r is the zero-sequence voltage similarity; set This is the zero-sequence voltage similarity setting value, i.e., the zero-sequence voltage similarity threshold, and its value ranges from [-1, 1]. Figure 8 For example, if the target reference fault point is... Figure 8 At point P of the first relay protection device, when the zero-sequence voltage similarity at point P satisfies formula (7), the ground fault at the output is at the reverse fault point F1; when the zero-sequence voltage similarity at point P does not satisfy formula (7), the ground fault at the output is at the forward fault point F2; if the target reference fault point is Figure 8At the second relay protection device Q, when the zero-sequence voltage similarity at Q satisfies formula (7), the outlet grounding fault is at the forward fault point F3; when the zero-sequence voltage similarity at Q does not satisfy formula (7), the outlet grounding fault is at the forward fault point F4.

[0107] r>r set (7)

[0108] In one embodiment, the description takes the determination of an outgoing ground fault in the transmission line between the new energy source and the power system as an example. The specific relationship structure is as follows: Figure 8 As shown, Figure 8 The new energy power source is connected to the power grid (i.e., the power system) through a step-up transformer and a transmission line. The neutral point on the high-voltage side of the transformer is directly grounded. M and N are the new energy side and the power grid side busbars of the transmission line, respectively. A first relay protection device P and a second relay protection device Q are installed on both sides of M and N, respectively. F1 and F2 are the reverse and forward output fault points at the first relay protection device P, respectively. F3 and F4 are the forward and reverse output fault points at the second relay protection device Q, respectively. The so-called output refers to the place near the relay protection device. F1 and F2 are both in the output area of ​​the first relay protection device P, and F3 and F4 are both in the output area of ​​the second relay protection device Q. F1 and F4 are reverse output fault points because F1 and F4 are no longer on the MN transmission line. F2 and F3 are forward output fault points because F2 and F3 are on the MN transmission line.

[0109] Furthermore, in the process of determining grounding faults at the outlet of new energy transmission lines, such as Figure 9 The specific judgment process is shown below. Figure 9 The protection installation location is the relay protection device location (such as...). Figure 8At points P and Q in the diagram, the protection activation element is a relay protection device. The output ground fault criterion is the output ground fault condition. The zero-sequence voltage similarity criterion is the comparison between the calculated zero-sequence voltage value and the preset zero-sequence voltage similarity threshold. The zero-sequence voltage similarity criterion is satisfied when the calculated zero-sequence voltage value is greater than the preset zero-sequence voltage similarity threshold. The first relay protection device at point P and the second relay protection device at point Q will continuously acquire voltage and current data. When the first relay protection device at point P and the second relay protection device at point Q are activated, they are simultaneously judged. If the first zero-sequence current and the first three-phase voltage corresponding to the first relay protection device at point P satisfy the first output ground fault condition, then the first relay protection device at point P is used as the target fault reference point. If the second zero-sequence current and the second three-phase voltage corresponding to the second relay protection device at point Q satisfy the second output ground fault condition, then the second relay protection device at point Q is used as the target fault reference point. The fault reference point, that is, the location of the first relay protection device P and the location of the second relay protection device Q, will only have an outlet grounding fault nearby. When it is determined that the corresponding outlet grounding fault conditions are met (see formula (1) and formula (2) for details), the relay protection device that meets the conditions is taken as the target fault reference point; then the zero-sequence voltage calculation value corresponding to the target fault reference point is calculated. The specific calculation formula can be as shown in formula (3) corresponding to the first relay protection device and formula (4) corresponding to the second relay protection device. After the zero-sequence voltage calculation value corresponding to the target fault reference point is obtained, the similarity between the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point is calculated, that is, the zero-sequence voltage similarity. The zero-sequence voltage similarity is compared with the zero-sequence voltage similarity threshold. If the target fault reference point is the location of the first relay protection device P and the zero-sequence voltage similarity satisfies formula (7), the outlet grounding fault is judged as a reverse fault, that is, it is in the reverse fault state. Figure 8 The reverse fault point is F1, and the reverse fault point is F2; ​​if the target fault reference point is Q at the second relay protection device, and the zero-sequence voltage similarity satisfies formula (7), the ground fault at the outlet is judged as a forward fault, that is, it is in the reverse fault point. Figure 8The forward fault point is F3, and the reverse fault point is F4. This completes the judgment of grounding faults at the output of renewable energy transmission lines. It effectively utilizes the characteristic that the current measured at the second relay protection device corresponding to a reverse fault on the renewable energy side (preset energy side) or a forward fault on the grid side (power system side) is the fault current provided by the grid side. The theoretical zero-sequence voltage calculation value is compared with the preset zero-sequence voltage similarity threshold to distinguish the direction of the grounding fault location corresponding to the first relay protection device P or the second relay protection device Q on the transmission line. This avoids the influence of the power source fault characteristics that renewable energy is not suitable for judging line faults based on positive sequence voltage, making the judgment of transmission line faults between renewable energy and the power system faster and improving the accuracy of renewable energy transmission line fault judgment.

[0110] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0111] Based on the same inventive concept, this application also provides a line fault detection device for implementing the line fault detection method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more line fault detection device embodiments provided below can be found in the limitations of the line fault detection method described above, and will not be repeated here.

[0112] In one embodiment, such as Figure 10 As shown, a line fault detection device is provided, including: an acquisition module 1000, a judgment module 1002, a calculation module 1004, and a determination module 1006, wherein:

[0113] The acquisition module 1000 is used to acquire the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side.

[0114] The judgment module 1002 is used to take the first relay protection device as the target fault reference point if the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, and to take the second relay protection device as the target fault reference point if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition.

[0115] The calculation module 1004 is used to calculate the zero-sequence voltage calculation value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point.

[0116] The determination module 1006 is used to determine the target fault location corresponding to the target fault reference point based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point.

[0117] In one embodiment, the determination module 1002 is further configured to: the first outlet grounding fault condition includes the first zero-sequence current being greater than the first preset current, and the first three-phase voltage being less than the first preset voltage; the second outlet grounding fault condition includes the second zero-sequence current being greater than the second preset current, and the second three-phase voltage being less than the second preset voltage.

[0118] In one embodiment, the calculation module 1004 is further configured to, when the target fault reference point is at the first relay protection device, acquire the first zero-sequence current measurement value currently corresponding to the target fault reference point, the line zero-sequence resistance and line zero-sequence inductance corresponding to the sending line, and the zero-sequence resistance and zero-sequence inductance corresponding to the power system side; and fuse the first zero-sequence current measurement value currently corresponding to the target fault reference point, the line zero-sequence resistance and line zero-sequence inductance corresponding to the sending line, and the zero-sequence resistance and zero-sequence inductance corresponding to the power system side to obtain the zero-sequence voltage calculation value corresponding to the target fault reference point.

[0119] In one embodiment, the calculation module 1004 is further configured to, when the target fault reference point is at the second relay protection device, acquire the current measurement value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side; and fuse the current measurement value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side to obtain the calculated value of the zero-sequence voltage corresponding to the target fault reference point.

[0120] In one embodiment, the calculation module 1004 is further configured to obtain the average measured voltage value corresponding to the zero-sequence voltage measurement value within a data window and the average calculated voltage value corresponding to the zero-sequence voltage calculation value within a data window; and to fuse the zero-sequence voltage calculation value, the zero-sequence voltage measurement value, the average measured voltage value, and the average calculated voltage value to obtain the zero-sequence voltage similarity.

[0121] In one embodiment, the determining module 1006 is further configured to, if the target fault reference point is at the location of the first relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the first relay protection device; when the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the forward fault location corresponding to the first relay protection device.

[0122] In one embodiment, the determining module 1006 is further configured to, if the target fault reference point is at the second relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the forward fault location corresponding to the second relay protection device; when the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the second relay protection device.

[0123] Each module in the aforementioned line fault diagnosis device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0124] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 11As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores relevant data during execution. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a line fault diagnosis method.

[0125] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 12 As shown, the computer device includes a processor, memory, input / output interfaces, a communication interface, a display unit, and an input device. The processor, memory, and input / output interfaces are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interfaces are used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a line fault diagnosis method. The display unit is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0126] Those skilled in the art will understand that Figure 11 and 12The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0127] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0128] In one embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0129] In one embodiment, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in the above method embodiments.

[0130] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data shall comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0131] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile 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 many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0132] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 specification.

[0133] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for determining line faults, characterized in that, The method includes: The first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side are respectively obtained; If the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, then the first relay protection device is taken as the target fault reference point; if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition, then the second relay protection device is taken as the target fault reference point. Calculate the zero-sequence voltage value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point. Based on the judgment results of the zero-sequence voltage similarity and zero-sequence voltage similarity threshold corresponding to the target fault reference point, the target fault location corresponding to the target fault reference point is determined.

2. The method according to claim 1, characterized in that, The first outlet grounding fault condition includes the first zero-sequence current being greater than the first preset current and the first three-phase voltage being less than the first preset voltage; the second outlet grounding fault condition includes the second zero-sequence current being greater than the second preset current and the second three-phase voltage being less than the second preset voltage.

3. The method according to claim 1, characterized in that, The calculation of the zero-sequence voltage corresponding to the target fault reference point includes: When the target fault reference point is at the first relay protection device, the current measurement value of the first zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance of the line corresponding to the sending line, and the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are obtained. The zero-sequence current measurement value corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance of the sending line, and the zero-sequence resistance and zero-sequence inductance of the power system side are fused together to obtain the zero-sequence voltage calculation value corresponding to the target fault reference point.

4. The method according to claim 1, characterized in that, The method further includes: When the target fault reference point is at the second relay protection device, the current measurement value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are obtained. The measured value of the second zero-sequence current corresponding to the target fault reference point, the zero-sequence resistance and zero-sequence inductance corresponding to the power system side are fused to obtain the calculated value of the zero-sequence voltage corresponding to the target fault reference point.

5. The method according to claim 1, characterized in that, The step of fusing the calculated value of the zero-sequence voltage corresponding to the target fault reference point and the measured value of the zero-sequence voltage to obtain the zero-sequence voltage similarity corresponding to the target fault reference point includes: Obtain the average measured voltage value corresponding to the zero-sequence voltage measurement value within a data window and the average calculated voltage value corresponding to the zero-sequence voltage calculation value within a data window; The zero-sequence voltage similarity is obtained by fusing the calculated zero-sequence voltage value, the measured zero-sequence voltage value, the average value of the measured voltage, and the average value of the calculated voltage.

6. The method according to claim 1, characterized in that, The determination of the target fault location corresponding to the target fault reference point based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point includes: If the target fault reference point is at the first relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the first relay protection device. When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the first relay protection device.

7. The method according to claim 1, characterized in that, The method further includes: If the target fault reference point is at the second relay protection device, then when the zero-sequence voltage similarity corresponding to the target fault reference point is greater than the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the positive fault location corresponding to the second relay protection device. When the zero-sequence voltage similarity corresponding to the target fault reference point is less than or equal to the zero-sequence voltage similarity threshold, the target fault location corresponding to the target fault reference point is the reverse fault location corresponding to the second relay protection device.

8. A line fault detection device, characterized in that, The device includes: The acquisition module is used to acquire the first zero-sequence current and the first three-phase voltage at the first relay protection device corresponding to the preset energy side, and the second zero-sequence current and the second three-phase voltage at the second relay protection device corresponding to the power system side. The judgment module is used to determine the first relay protection device as the target fault reference point if the first zero-sequence current and the first three-phase voltage meet the first outlet grounding fault condition, and the second relay protection device as the target fault reference point if the second zero-sequence current and the second three-phase voltage meet the second outlet grounding fault condition. The calculation module is used to calculate the zero-sequence voltage calculation value corresponding to the target fault reference point, obtain the zero-sequence voltage measurement value corresponding to the target fault reference point, and fuse the zero-sequence voltage calculation value and the zero-sequence voltage measurement value corresponding to the target fault reference point to obtain the zero-sequence voltage similarity corresponding to the target fault reference point. The determination module is used to determine the target fault location corresponding to the target fault reference point based on the judgment results of the zero-sequence voltage similarity and the zero-sequence voltage similarity threshold corresponding to the target fault reference point.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

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

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