Fault line detection method and device for high-resistance grounding fault of power distribution network

Abstract

The invention relates to the technical field of power systems, in particular to a fault line detection method and device for a high-resistance grounding fault of a power distribution network. Comprising the following steps: acquiring three-phase voltage information and three-phase current information corresponding to each line in a power distribution network acquired by a line terminal device; according to the three-phase voltage information corresponding to each line in the power distribution network, whether a high-resistance grounding fault exists in the power distribution network is judged; if the power distribution network has the high-resistance grounding fault, calculating power quotient information corresponding to each line according to the three-phase voltage information and the three-phase current information corresponding to the line; and sending the power quotient information corresponding to each line to a fault line selection system, so that the fault line selection system determines a fault line in the power distribution network according to the power quotient information corresponding to each line. According to the method, the fault line in the power distribution network can be rapidly and accurately detected for the power distribution network with the high-resistance grounding fault.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of power systems, and in particular to a method and device for detecting a fault line for a high-resistance grounding fault in a distribution network. Background Art

[0002] As an important link in transferring electric energy from the transmission network to users, the safety and reliability of the distribution network directly affect the supply of electric energy. High-resistance grounding fault is a common type of fault in the distribution network, which usually manifests as an accidental short circuit between the equipment or line and the ground. If this type of fault exists in the distribution network for a long time, it will not only cause power outages, but may also cause serious safety hazards such as equipment damage, personal injury and electrical fires. Therefore, it is crucial to quickly and accurately detect high-resistance grounding faults in the distribution network to ensure the normal operation of the power system.

[0003] However, the traditional high-resistance ground fault detection method mainly relies on manual inspection and circuit cutting. Although this method can identify ground faults to a certain extent, it has disadvantages such as delayed response, risk of missed detection, and short-term power outages. In addition, with the development of intelligent distribution networks, traditional maintenance methods have gradually become outdated and cannot meet the needs of real-time monitoring and rapid response.

[0004] Therefore, a method that can quickly and accurately detect the faulty line for high-resistance grounding faults in distribution networks needs to be studied urgently. Summary of the invention

[0005] The present application provides a fault line detection method and device for a high-resistance grounding fault in a distribution network, which can quickly and accurately detect a fault line in a distribution network where a high-resistance grounding fault occurs.

[0006] In a first aspect, a fault line detection method for a high-resistance grounding fault in a distribution network is provided, comprising:

[0007] Obtaining three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device;

[0008] According to the three-phase voltage information corresponding to each line in the distribution network, determine whether there is a high-resistance grounding fault in the distribution network;

[0009] If there is a high-resistance grounding fault in the distribution network, the power quotient information corresponding to each line is calculated based on the three-phase voltage information and three-phase current information corresponding to the line;

[0010] The power quotient information corresponding to each line is sent to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line.

[0011] Optionally, if there is a high-resistance grounding fault in the distribution network, for each line, the power quotient information corresponding to the line is calculated according to the three-phase voltage information and the three-phase current information corresponding to the line, including:

[0012] For each line, calculate the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line;

[0013] For each line, the additional active power information and the additional reactive power information corresponding to the line are calculated according to the additional fault current information and the three-phase voltage information corresponding to the line;

[0014] For each line, according to the ratio between the additional active power information and the additional reactive power information corresponding to the line, the three-phase power ratio corresponding to the line is calculated;

[0015] For each line, the power quotient information corresponding to the line is calculated according to the three-phase power ratio corresponding to the line.

[0016] Optionally, for each line, according to the three-phase current information corresponding to the line, the fault additional current information corresponding to the line is calculated, including:

[0017] For each phase line of each line, according to the phase current information collected by the line terminal device at the first preset time and the second preset time, respectively, the phase fault additional current information corresponding to the phase line is calculated; the first preset time is the time when the line terminal device collects the phase current information of the phase line after the distribution network fails; the second preset time is the time when the line terminal device collects the phase current information of the phase line before the distribution network fails;

[0018] For each line, the phase fault additional current information corresponding to each of the three-phase lines is used as the fault additional current information corresponding to the line.

[0019] Optionally, for each line, according to the fault additional current information and three-phase voltage information corresponding to the line, additional active power information and additional reactive power information corresponding to the line are calculated, including:

[0020] For each phase line of each line, calculate the phase additional active power information and phase additional reactive power information corresponding to the phase line according to the phase fault additional current information corresponding to the phase line and the phase voltage information collected by the line terminal device on the phase line;

[0021] For each line, the phase additional active power information corresponding to each of the three-phase lines is used as the additional active power information corresponding to the line;

[0022] For each line, the phase additional reactive power information corresponding to each of the three-phase lines is used as the additional reactive power information corresponding to the line;

[0023] For each line, according to the ratio between the additional active power information and the additional reactive power information corresponding to the line, the three-phase power ratio corresponding to the line is calculated, including:

[0024] For each phase line of each line, the phase additional active power information and the phase additional reactive power information corresponding to the phase line are compared and calculated to obtain the phase power ratio corresponding to the phase line;

[0025] For each line, the phase power ratio corresponding to each of the three-phase lines is used as the three-phase power ratio corresponding to the line.

[0026] Optionally, for each line, according to the three-phase power ratio corresponding to the line, power quotient information corresponding to the line is calculated, including:

[0027] For each line, according to the phase power ratios corresponding to the three-phase lines, a phase line with a maximum phase power ratio is determined;

[0028] For each line, the phase power ratio corresponding to the phase line with the maximum phase power ratio and the sum of the phase power ratios corresponding to the other two phase lines are calculated to obtain the power quotient information corresponding to the line.

[0029] Optionally, judging whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network includes:

[0030] Get the rated voltage of the distribution network;

[0031] Determine, according to the rated voltage, a maximum threshold range corresponding to the maximum phase voltage information of each line in the distribution network, and a minimum threshold range corresponding to the minimum phase voltage information of each line in the distribution network;

[0032] The three-phase voltage information corresponding to each line is compared with the maximum threshold range and the minimum threshold range respectively, and when the maximum phase voltage information in a line is greater than the maximum threshold range and the minimum phase voltage information in the line is within the minimum threshold range, it is determined that there is a high-resistance grounding fault in the distribution network.

[0033] Optionally, sending the power quotient information corresponding to each line to the fault line selection system so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line, including:

[0034] The line with the largest power quotient information is determined as the fault line to complete the detection of the fault line in the distribution network.

[0035] In a second aspect, a fault line detection device for a high-resistance grounding fault in a distribution network is provided, comprising:

[0036] An acquisition module, used to acquire three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device;

[0037] A judgment module is used to judge whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network;

[0038] A power quotient information calculation module is used to calculate the power quotient information corresponding to each line according to the three-phase voltage information and three-phase current information corresponding to the line if there is a high-resistance grounding fault in the distribution network;

[0039] The fault line determination module is used to send the power quotient information corresponding to each line to the fault line selection system, so that the fault line selection system can determine the fault line in the distribution network according to the power quotient information corresponding to each line.

[0040] According to a third aspect, an electronic device is provided, comprising: a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method in the first aspect or its various implementations.

[0041] According to a fourth aspect, a computer-readable storage medium is provided for storing a computer program, wherein the computer program enables a computer to execute the method according to the first aspect or its various implementations.

[0042] Through the technical solution provided by the present application, by judging whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network; then when there is a high-resistance grounding fault in the distribution network, the power quotient information with obvious characteristic components is calculated using the three-phase voltage information and three-phase current information corresponding to each line; finally, the fault line selection system is used to quickly and accurately determine the fault line in the distribution network according to the power quotient information corresponding to each line. It can be seen that the method provided by the present application can quickly and accurately determine the fault line in the distribution network for a distribution network with a high-resistance grounding fault.

[0043] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 An application scenario diagram provided for an embodiment of the present application;

[0046] Figure 2 A flow chart of a fault line detection method for a high-resistance grounding fault in a distribution network provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of a fault line detection device for a high-resistance grounding fault in a distribution network provided in an embodiment of the present application;

[0048] Figure 4 It is a schematic block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] As mentioned above, although domestic and foreign researchers have begun to explore high-resistance grounding fault detection methods based on modern technology in recent years. These emerging methods use advanced sensor technology, data analysis algorithms, and intelligent monitoring equipment to collect current, voltage and other parameters in real time, and deeply analyze their changing laws to achieve rapid positioning and identification of high-resistance grounding faults. For example, the use of phasor measurement units and smart substation technology can significantly improve the accuracy and efficiency of fault detection. In addition, the introduction of machine learning and big data analysis methods has provided new ideas for high-resistance grounding fault detection, making fault judgment more intelligent and automated. These technologies have made many research advances and test results, but they are still not perfect. Because the fault transition resistance of high-resistance grounding faults is large, the fault current is small, and the characteristic components in the fault transition process are not obvious enough, many existing methods are even more difficult to make accurate judgments, resulting in the inability to detect and handle grounding faults in a timely manner. How to quickly and accurately detect high-resistance grounding faults has become an important topic in current distribution network technology research.

[0052] In order to solve the above technical problems, the invention concept of the present application is: obtain the three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device; judge whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network; if there is a high-resistance grounding fault in the distribution network, then for each line, according to the three-phase voltage information and three-phase current information corresponding to the line, calculate the power quotient information corresponding to the line; send the power quotient information corresponding to each line to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line. The method provided by the present application can quickly and accurately determine the fault line in the distribution network where a high-resistance grounding fault occurs.

[0053] It should be understood that the technical solution of the present application can be applied to the following scenarios, but is not limited to:

[0054] In some possible implementations, Figure 1 An application scenario diagram provided for an embodiment of the present application, such as Figure 1 As shown, the application scenario may include an electronic device 110 and a network device 120. The electronic device 110 may establish a connection with the network device 120 via a wired network or a wireless network.

[0055] Exemplarily, the electronic device 110 may be a desktop computer, a laptop computer, a tablet computer, etc., but is not limited thereto. The network device 120 may be a terminal device or a server, but is not limited thereto. In one embodiment of the present application, the electronic device 110 may send a request message to the network device 120, and the request message may be used to request to obtain the three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device. Further, the electronic device 110 may receive a response message sent by the network device 120, and the response message includes obtaining the three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device.

[0056] also, Figure 1 An electronic device 110 and a network device 120 are provided as an example, but other numbers of electronic devices and network devices may actually be included, and the present application does not impose any limitation on this.

[0057] In other possible implementations, the technical solution of the present application may also be executed by the above-mentioned electronic device 110, or the technical solution of the present application may also be executed by the above-mentioned network device 120, and the present application does not impose any limitation on this.

[0058] After introducing the application scenarios of the embodiments of the present application, the technical solution of the present application will be described in detail below:

[0059] Figure 2 A flow chart of a fault line detection method for a high-resistance grounding fault in a distribution network provided in an embodiment of the present application. The method can be performed as follows: Figure 1 The electronic device 110 shown in the figure performs, but is not limited to this. Figure 2 As shown, the method may include the following steps:

[0060] S210. Acquire three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device.

[0061] It should be noted that a line terminal device is configured at the head end of each line in the distribution network. Here, the line terminal device has the ability to collect three-phase voltage signals and three-phase current signals of the line configured with it, and the line terminal device has the ability to process the collected information; wherein, the line terminal device is communicatively connected with the fault line selection system.

[0062] Here, the three phases corresponding to each line in the distribution network may be phase A, phase B, and phase C respectively.

[0063] S220. Determine whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network.

[0064] When a high-resistance grounding fault exists in the distribution network, the balance state of the three-phase voltage information corresponding to at least one line in the distribution network will change, that is, the effective value corresponding to the three-phase voltage information in the faulty line will change in a certain regularity. Therefore, here, the three-phase voltage information corresponding to each line in the distribution network can be used to quickly determine whether there is a high-resistance grounding fault in the distribution network.

[0065] S230: If a high-resistance grounding fault exists in the distribution network, for each line, the power quotient information corresponding to the line is calculated according to the three-phase voltage information and the three-phase current information corresponding to the line.

[0066] When a high-resistance grounding fault occurs in the distribution network, since the fault transition resistance of the distribution network is large and the fault current of the distribution network is small, the characteristic component of the distribution network during the fault transition process is not obvious enough. When a high-resistance grounding fault occurs in the distribution network, the power quotient information corresponding to the line is relatively large and has an obvious characteristic component. Therefore, the power quotient information calculated based on the three-phase voltage information and three-phase current information corresponding to the line can facilitate the fault line selection system in step S240 to determine the faulty line in the distribution network.

[0067] In addition, if there is no high-resistance grounding fault in the distribution network, the process returns to step S210 so that the line terminal device continues to collect three-phase voltage information and three-phase current information corresponding to each line in the distribution network, thereby achieving continuous detection of high-resistance grounding faults in the distribution network.

[0068] S240. Send the power quotient information corresponding to each line to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line.

[0069] Since, when a high-resistance grounding fault occurs in the distribution network, the power quotient information corresponding to the line is relatively large and has obvious characteristic components, the fault line selection system here can quickly and accurately determine the fault line in the distribution network according to the power quotient information corresponding to each line.

[0070] By adopting the above method, it is determined whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network; when there is a high-resistance grounding fault in the distribution network, the power quotient information with obvious characteristic components is calculated using the three-phase voltage information and three-phase current information corresponding to each line; finally, the fault line selection system is used to quickly and accurately determine the fault line in the distribution network according to the power quotient information corresponding to each line. It can be seen that the method provided by the present application can quickly and accurately determine the fault line in the distribution network for a distribution network with a high-resistance grounding fault.

[0071] In some possible embodiments, if there is a high-resistance ground fault in the distribution network, for each line, according to the three-phase voltage information and three-phase current information corresponding to the line, the power quotient information corresponding to the line is calculated, which may include the following steps:

[0072] S310. For each line, calculate the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line.

[0073] Here, the fault additional current information is current information excluding interference of three-phase load current.

[0074] S320. For each line, calculate the additional active power information and the additional reactive power information corresponding to the line according to the fault additional current information and the three-phase voltage information corresponding to the line.

[0075] S330 . For each line, calculate the three-phase power ratio corresponding to the line according to the ratio between the additional active power information and the additional reactive power information corresponding to the line.

[0076] S340. For each line, calculate the power quotient information corresponding to the line according to the three-phase power ratio corresponding to the line.

[0077] Here, the additional active power information and additional reactive power information are calculated through the additional fault current information and the three-phase voltage information corresponding to the line, and then the three-phase power ratio is calculated based on the additional active power information and the additional reactive power information. The power quotient information that can detect the high-resistance grounding fault can be calculated through the three-phase power ratio.

[0078] It should be noted that for non-fault lines, the impedance to ground of line phases A, B, and C is similar, so the difference in the three-phase power ratios obtained is not large, and therefore, the power quotient information calculated by the three-phase power ratio is relatively small. However, for fault lines, the impedance to ground of the phase where the high-resistance ground fault is located in line phases A, B, and C is significantly different from that of other phases due to the superposition of the fault transition resistance, so the three-phase power ratio obtained in the phase where the high-resistance ground fault is located in the line is also significantly different from that of other phases, that is, the difference between the three-phase power ratios is large, and the power quotient information obtained according to the three-phase power ratio corresponding to the line is also large.

[0079] By adopting the above method, the power quotient information corresponding to the line can be quickly calculated according to the three-phase voltage information and three-phase current information corresponding to the line, so as to speed up the detection of faulty lines in the distribution network.

[0080] In some possible embodiments, for each line, calculating the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line may include the following steps:

[0081] S410. For each phase line of each line, calculate the phase fault additional current information corresponding to the phase line according to the phase current information collected by the line terminal device at the first preset time and the second preset time.

[0082] Here, the first preset time is the time when the line terminal device collects phase current information from the phase line after a fault occurs in the distribution network; the second preset time is the time when the line terminal device collects phase current information from the phase line before a fault occurs in the distribution network.

[0083] The calculation method of the line terminal device for the phase fault additional current information corresponding to the A phase line, the B phase line, and the C phase line in the line is as follows:

[0084]

[0085] In the formula, I A_k ,I B_k ,I C_k are the additional current information of the phase fault corresponding to the kth phase A, phase B, and phase C respectively; the value of k is an integer of 1, 2, 3, ... N; N is the number of sampling times of the line terminal device in one power frequency cycle; Δt is the sampling interval time; t0 is the time when the fault line selection system is started, that is, the time when the distribution network fails; They are the sampling values ​​of the A-phase current signal at the moment t0+kΔt and the moment t0-2NΔt+kΔt respectively; and the same applies to phases B and C; wherein, t0+kΔt is the first preset moment, i.e., the moment when the line terminal device collects the phase current information of the phase line after a fault occurs in the distribution network; t0-2NΔt+kΔt is the second preset moment, i.e., the moment when the line terminal device collects the phase current information of the phase line before a fault occurs in the distribution network.

[0086] It should be noted that by calculating the difference between the phase current information collected by the line terminal device on a phase line at a first preset time and the phase current information collected on the phase line at a second preset time, the phase fault additional current information can be obtained, which is the phase line-to-ground current induced after the fault without the load current.

[0087] S420: For each line, use the phase fault additional current information corresponding to each of the three-phase lines as the fault additional current information corresponding to the line.

[0088] Here, by using the phase fault additional current information corresponding to each of the three-phase lines as the fault additional current information corresponding to the line, when calculating the additional active power information and additional reactive power information corresponding to the line, the additional active power information and additional reactive power information corresponding to each of the three-phase lines can be used to facilitate the calculation of the power ratio corresponding to each of the three-phase lines in subsequent steps.

[0089] By adopting the above method, the fault additional current information corresponding to each line can be quickly calculated, and the obtained fault additional current information is the phase line-to-ground current induced after the fault without the load current.

[0090] In some possible embodiments, for each line, according to the fault additional current information and three-phase voltage information corresponding to the line, calculating the additional active power information and additional reactive power information corresponding to the line may include the following steps:

[0091] S510. For each phase line of each line, calculate the phase additional active power information and the phase additional reactive power information corresponding to the phase line according to the phase fault additional current information corresponding to the phase line and the phase voltage information collected by the line terminal device on the phase line.

[0092] Here, the phase additional active power information corresponding to phase A, phase B, and phase C can be calculated by the following formula:

[0093]

[0094] Where P A , P B , P C They are the additional active power information corresponding to the A phase line, the B phase line and the C phase line respectively; are the phase voltage information corresponding to phase A, phase B, and phase C at the time t0+kΔt; I A_k ,I B_k ,I C_k They are the phase fault additional current information corresponding to the kth phase A, phase B, and phase C respectively; the value of k is an integer of 1, 2, 3, ... N; N is the number of sampling times of the line terminal device in one power frequency cycle.

[0095] Here, the phase additional reactive power information corresponding to phase A, phase B, and phase C can be calculated by the following formula:

[0096]

[0097] In the formula, Q A , Q B , Q C They are the additional reactive power information corresponding to the A phase line, the B phase line and the C phase line respectively; are the phase voltage information corresponding to phase A, phase B, and phase C at the time t0+0.25NΔt+kΔt; I A_k ,I B_k ,I C_kThey are the phase fault additional current information corresponding to the kth phase A, phase B, and phase C respectively; the value of k is an integer of 1, 2, 3, ... N; N is the number of sampling times of the line terminal device in one power frequency cycle.

[0098] Since the phase additional active power information corresponding to the A-phase, B-phase, and C-phase lines is obtained by multiplying and accumulating the voltage information of the A-phase, B-phase, and C-phase at the time t0+kΔt and the phase fault additional current information corresponding to the time, and the reactive power information differs from the active power information by 90 degrees, for one power frequency cycle (360 degrees, N samplings), the reactive power information is converted to the sampling time of the line terminal device for the line, which differs by 0.25NΔt. Therefore, the phase additional reactive power is obtained here by multiplying and accumulating the voltage information of the A-phase, B-phase, and C-phase at the time t0+0.25NΔt+kΔt and the phase fault additional current information at the time t0+kΔt.

[0099] S520: For each line, the phase additional active power information corresponding to each of the three-phase lines is used as the additional active power information corresponding to the line.

[0100] Here, by using the phase additional active power information corresponding to each of the three-phase lines as the additional active power information corresponding to the line, it is convenient to calculate the three-phase power ratio corresponding to the line in subsequent steps.

[0101] S530: For each line, the phase additional reactive power information corresponding to each of the three-phase lines is used as the additional reactive power information corresponding to the line.

[0102] Here, by using the phase additional reactive power information corresponding to each of the three-phase lines as the additional reactive power information corresponding to the line, it is convenient to calculate the three-phase power ratio corresponding to the line in subsequent steps.

[0103] By adopting the above method, the additional active power information and the additional reactive power information corresponding to each line can be quickly calculated, and the three-phase power ratio corresponding to the line can be quickly calculated based on the obtained additional active power information and additional reactive power information.

[0104] Accordingly, for each line, according to the ratio between the additional active power information and the additional reactive power information corresponding to the line, the three-phase power ratio corresponding to the line is calculated, including:

[0105] S610 . For each phase line of each line, perform ratio calculation on the phase-added active power information and the phase-added reactive power information corresponding to the phase line to obtain a phase power ratio corresponding to the phase line.

[0106] Here, the phase power ratio corresponding to the A phase, B phase, and C phase lines is calculated using the following formula:

[0107]

[0108] In the formula, δ A , δ B , δ C are the phase power ratios corresponding to phase A, phase B, and phase C respectively; P A , P B , P C They are the additional active power information corresponding to phase A, phase B, and phase C respectively; Q A , Q B , Q C They are the additional reactive power information corresponding to phase A, phase B and phase C respectively.

[0109] For example, in P A , P B , P C When the values ​​are 8.47×104W, 2.39×106W, and 9.58×104W respectively, and Q A , Q B , Q C When the phase power ratios of phase A, phase B, and phase C are 1.16×105Var, 2.63×105Var, and 1.54×105Var, respectively, the corresponding phase power ratios δ can be calculated. A , δ B , δ C They are 0.73, 9.13 and 0.62 respectively.

[0110] S620: For each line, the phase power ratios corresponding to the three-phase lines are used as the three-phase power ratios corresponding to the line.

[0111] Here, by taking the phase power ratios corresponding to the three-phase lines as the three-phase power ratios corresponding to the line, it is convenient to calculate the power quotient information corresponding to the line in subsequent steps.

[0112] By adopting the above method, the three-phase power ratio corresponding to each line can be quickly calculated, and the power quotient information corresponding to the line can be quickly calculated according to the obtained three-phase power ratio.

[0113] In some possible embodiments, for each line, according to the three-phase power ratio corresponding to the line, calculating the power quotient information corresponding to the line may include the following steps:

[0114] S710 . For each line, determine a phase line having a maximum phase power ratio according to the phase power ratios corresponding to the three-phase lines.

[0115] S720: For each line, calculate the ratio of the phase power ratio corresponding to the phase line with the maximum phase power ratio and the sum of the phase power ratios corresponding to the other two phase lines to obtain power quotient information corresponding to the line.

[0116] Here, the power quotient information corresponding to the line can be calculated by the following formula:

[0117]

[0118] Where S is the power quotient information corresponding to the line; δ A , δ B , δ C They are the phase power ratios corresponding to phase A, phase B, and phase C lines respectively.

[0119] Since, for the non-fault line in the distribution network, the impedance of phase A, phase B, and phase C in the line to ground is similar, so δ A , δ B , δ C The difference between the phase power ratios corresponding to phase A, phase B, and phase C is not large, that is, δ A , δ B , δ C The corresponding values ​​are relatively small. However, for the fault line, the impedance to ground of the phase where the high-resistance ground fault is located in phase A, phase B, and phase C is significantly different from that of other phases due to the superposition of the fault transition resistance. Therefore, the power ratio obtained in the phase where the high-resistance ground fault is located in phase A, phase B, and phase C is also significantly different from that of other phases, that is, the difference between the three-phase power ratios is large, and the power quotient information corresponding to the obtained line is also large.

[0120] By δ A , δ B , δ C Taking 0.73, 9.13 and 0.62 as examples, the power quotient information corresponding to the line can be calculated as 6.76 through the above formula.

[0121] By adopting the above method, the power quotient information corresponding to the line can be quickly calculated by calculating the ratio of the phase line with the maximum phase power ratio among the three-phase lines of the line with the sum of the phase power ratios corresponding to the other two phase lines, so as to improve the detection efficiency of the fault line in the distribution network based on the power quotient information in the subsequent steps.

[0122] In some possible embodiments, judging whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network may include the following steps:

[0123] S810. Obtain the rated voltage of the distribution network.

[0124] If there is a high-resistance grounding fault in the distribution network, the balance of the three-phase voltage information will inevitably be broken, resulting in the effective value of some phase voltage information in the three-phase voltage signal being greater than and some phase voltages have effective values ​​less than The situation, in which U E is the rated voltage. Therefore, obtaining the rated voltage of the distribution network here can facilitate the judgment of whether there is a high-resistance grounding fault in the distribution network.

[0125] S820. Determine, according to the rated voltage, a maximum threshold range corresponding to the maximum phase voltage information of each line in the distribution network, and a minimum threshold range corresponding to the minimum phase voltage information of each line in the distribution network.

[0126] Here, the upper limit of the maximum threshold range corresponding to each line in the distribution network determined according to the rated voltage can be The minimum threshold range can be to Among them, U E is the rated voltage.

[0127] Among them, this application is mainly aimed at high-resistance grounding faults, so the minimum value of the three-phase voltage corresponding to the line is limited to greater than Therefore, a fault that does not meet this condition does not belong to the high-resistance grounding fault targeted by this application.

[0128] S830. Compare the three-phase voltage information corresponding to each line with the maximum threshold range and the minimum threshold range respectively, and determine that a high-resistance grounding fault exists in the distribution network when the maximum phase voltage information in a line is greater than the maximum threshold range and the minimum phase voltage information in the line is within the minimum threshold range.

[0129] Here, the following formula can be used to determine whether there is a high-resistance grounding fault in the distribution network:

[0130]

[0131] Where U A , U B , U C They are the effective values ​​corresponding to the three-phase voltage information of the line, U E is the rated voltage of the distribution network.

[0132] The maximum phase voltage information in a line is greater than When the minimum phase voltage information in the line is and When the voltage is between 0 and 1, it can be determined that there is a high-resistance grounding fault in the distribution network.

[0133] Taking the rated voltage of 10kV as an example, the effective value U of the three-phase voltage information corresponding to line A is A , U B , U C When the voltages are 9.05 kV, 0.89 kV, and 9.55 kV respectively, the line terminal device at the head end of line A can detect the three-phase voltage information corresponding to line A according to the above formula, and can determine that there is a high-resistance grounding fault in the distribution network.

[0134] By adopting the above method, the maximum threshold range corresponding to the maximum phase voltage information of each line in the distribution network determined by the rated voltage, and the minimum threshold range corresponding to the minimum phase voltage information of each line in the distribution network, when the maximum phase voltage information of the line in the distribution network is greater than the maximum threshold range and the minimum phase voltage information of the line is within the minimum threshold range, it can be quickly determined that there is a high-resistance grounding fault in the distribution network, so as to complete the rapid detection of the existence of a high-resistance grounding fault in the distribution network.

[0135] In some possible embodiments, the power quotient information corresponding to each line is sent to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line, which can include: determining the line with the largest power quotient information as the fault line to complete the detection of the fault line in the distribution network.

[0136] Exemplarily, if the power quotient information corresponding to the four lines is 0.77, 6.76, 0.80, and 0.74 respectively, the line with the power quotient information of 6.76 is determined as the faulty line.

[0137] Here, since the power quotient information can represent the difference between the phase power ratios corresponding to each of the three-phase lines, the fault line selection system can effectively detect the line where the high-resistance grounding fault is located, that is, the fault line, by verifying the power quotient information uploaded by the line terminal device at the head end of each line.

[0138] By adopting the above method, the fault line selection system can quickly and accurately determine the fault line in the distribution network.

[0139] Figure 3 1 is a schematic diagram of a fault line detection device 900 for a high-resistance grounding fault in a distribution network according to an embodiment of the present invention. The device 900 includes:

[0140] An acquisition module 910 is used to acquire three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device;

[0141] A judgment module 920 is used to judge whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network;

[0142] The power quotient information calculation module 930 is used to calculate the power quotient information corresponding to each line according to the three-phase voltage information and three-phase current information corresponding to the line if there is a high-resistance grounding fault in the distribution network;

[0143] The fault line determination module 940 is used to send the power quotient information corresponding to each line to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each line.

[0144] In some implementations, the power quotient information calculation module 930 includes:

[0145] A first calculation unit is used to calculate, for each line, the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line;

[0146] A second calculation unit is used to calculate, for each line, additional active power information and additional reactive power information corresponding to the line according to the fault additional current information and three-phase voltage information corresponding to the line;

[0147] A third calculation unit is used to calculate, for each line, a three-phase power ratio corresponding to the line according to a ratio between the additional active power information and the additional reactive power information corresponding to the line;

[0148] The fourth calculation unit is used to calculate the power quotient information corresponding to each line according to the three-phase power ratio corresponding to the line.

[0149] In some possible implementations, the first computing unit includes:

[0150] A first calculation subunit is used to calculate, for each phase line of each line, the phase fault additional current information corresponding to the phase line according to the phase current information collected by the line terminal device at a first preset time and a second preset time respectively; the first preset time is the time when the line terminal device collects the phase current information of the phase line after a fault occurs in the distribution network; the second preset time is the time when the line terminal device collects the phase current information of the phase line before the fault occurs in the distribution network;

[0151] The second calculation subunit is used to use, for each line, the phase fault additional current information corresponding to each of the three-phase lines as the fault additional current information corresponding to the line.

[0152] In some possible implementations, the second computing unit includes:

[0153] The second calculation subunit is used to calculate the phase additional active power information and the phase additional reactive power information corresponding to each phase line of each line according to the phase fault additional current information corresponding to the phase line and the phase voltage information collected by the line terminal device on the phase line;

[0154] A third calculation subunit is used for taking, for each line, the phase additional active power information corresponding to each of the three-phase lines as the additional active power information corresponding to the line;

[0155] A fourth calculation subunit is used for taking, for each line, phase additional reactive power information corresponding to each of the three-phase lines as additional reactive power information corresponding to the line;

[0156] Accordingly, the third computing unit includes:

[0157] A fifth calculation subunit is used for performing a ratio calculation on the phase-added active power information and the phase-added reactive power information corresponding to each phase line of each line to obtain a phase power ratio corresponding to the phase line;

[0158] The sixth calculation subunit is used to use, for each line, the phase power ratio corresponding to each of the three-phase lines as the three-phase power ratio corresponding to the line.

[0159] In some implementations, the fourth computing unit includes:

[0160] The phase line determination subunit is used to determine the phase line with the maximum phase power ratio for each line according to the phase power ratios corresponding to the three-phase lines;

[0161] The power quotient information calculation unit is used to calculate the phase power ratio corresponding to the phase line with the maximum phase power ratio and the sum of the phase power ratios corresponding to the other two phase lines for each line to obtain the power quotient information corresponding to the line.

[0162] In some implementations, the determination module 920 includes:

[0163] A rated voltage acquisition unit, used for acquiring the rated voltage of the distribution network;

[0164] A threshold range determination unit, which determines, according to the rated voltage, a maximum threshold range corresponding to the maximum phase voltage information in each line in the distribution network, and a minimum threshold range corresponding to the minimum phase voltage information in each line in the distribution network;

[0165] The high-resistance grounding fault determination unit is used to compare the three-phase voltage information corresponding to each line with the maximum threshold range and the minimum threshold range respectively, and determine that there is a high-resistance grounding fault in the distribution network when the maximum phase voltage information in a line is greater than the maximum threshold range and the minimum phase voltage information in the line is within the minimum threshold range.

[0166] In some implementations, the fault line determination module 940 includes:

[0167] The fault line detection unit is used to determine the line with the largest power quotient information as the fault line, so as to complete the detection of the fault line in the distribution network.

[0168] It should be understood that an embodiment of a fault line detection device for a high-resistance grounding fault in a distribution network and an embodiment of a fault line detection method for a high-resistance grounding fault in a distribution network may correspond to each other, and similar descriptions may refer to an embodiment of a fault line detection method for a high-resistance grounding fault in a distribution network. To avoid repetition, they will not be described here. Specifically, Figure 3 The device 900 shown can execute the above-mentioned embodiment of the fault line detection method for high-resistance grounding faults in the distribution network, and the above-mentioned and other operations and / or functions of each module in the device 900 are respectively for realizing the corresponding processes in the above-mentioned fault line detection method for high-resistance grounding faults in the distribution network. For the sake of brevity, they will not be repeated here.

[0169] In the above, the device 900 of the embodiment of the present invention is described from the perspective of functional modules in conjunction with the accompanying drawings. It should be understood that the functional module can be implemented in hardware form, can be implemented in software form, or can be implemented in combination with hardware and software modules. Specifically, the steps of the fault line detection method for high-resistance grounding fault in the distribution network and the detection method embodiment in the embodiment of the present invention can be completed by the hardware integrated logic circuit and / or software form instructions in the processor, and the steps of the fault line detection method for high-resistance grounding fault in the distribution network and the detection method disclosed in the embodiment of the present invention can be directly embodied as a hardware decoding processor to execute, or a combination of hardware and software modules in the decoding processor to execute. Optionally, the software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above-mentioned fault line detection method for high-resistance grounding fault in the distribution network and the detection method embodiment in conjunction with its hardware.

[0170] Figure 4 is a schematic block diagram of an electronic device 110 according to an embodiment of the present invention.

[0171] like Figure 4 As shown, the electronic device 110 may include:

[0172] The memory 111 and the processor 112, the memory 111 is used to store the computer program and transmit the program code to the processor 112. In other words, the processor 112 can call and run the computer program from the memory 111 to implement the method in the embodiment of the present invention.

[0173] For example, the processor 112 may be configured to execute the above method embodiments according to instructions in the computer program.

[0174] In some embodiments of the present invention, the electronic device 110 may include but is not limited to:

[0175] General-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc.

[0176] In some embodiments of the present invention, the memory 111 includes but is not limited to:

[0177] Volatile memory and / or non-volatile memory. Among them, the non-volatile memory can be read-only memory (ROM), programmable ROM (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM).

[0178] In some embodiments of the present invention, the computer program may be divided into one or more modules, which are stored in the memory 111 and executed by the processor 112 to complete the method provided by the present invention. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the controller.

[0179] like Figure 4 As shown, the electronic device 110 may further include:

[0180] The transceiver 113 may be connected to the processor 112 or the memory 111 .

[0181] The processor 112 may control the transceiver 113 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices. The transceiver 113 may include a transmitter and a receiver. The transceiver 113 may further include an antenna, and the number of antennas may be one or more.

[0182] It should be understood that the various components in the electronic device are connected via a bus system, wherein the bus system includes not only a data bus but also a power bus, a control bus and a status signal bus.

[0183] The present invention also provides a computer storage medium having a computer program stored thereon, which, when executed by a computer, enables the computer to perform the method of the above method embodiment. In other words, an embodiment of the present invention also provides a computer program product containing instructions, which, when executed by a computer, enables the computer to perform the method of the above method embodiment.

[0184] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integration. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (e.g., a solid-state drive (Solid State Disk, SSD)), etc.

[0185] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0186] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the module is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0187] The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. For example, each functional module in each embodiment of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0188] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this application, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A fault line detection method for high-resistance grounding faults in a distribution network, characterized in that: include: Obtaining three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device; Determining whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network; If a high-resistance grounding fault exists in the distribution network, for each of the lines, the power quotient information corresponding to the line is calculated according to the three-phase voltage information and the three-phase current information corresponding to the line; The power quotient information corresponding to each of the lines is sent to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each of the lines.

2. The method according to claim 1, characterized in that If a high-resistance ground fault exists in the distribution network, for each of the lines, the power quotient information corresponding to the line is calculated according to the three-phase voltage information and the three-phase current information corresponding to the line, including: For each of the lines, calculating the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line; For each of the lines, according to the fault additional current information and three-phase voltage information corresponding to the line, calculate the additional active power information and additional reactive power information corresponding to the line; For each of the lines, according to the ratio between the additional active power information and the additional reactive power information corresponding to the line, calculate the three-phase power ratio corresponding to the line; For each of the lines, the power quotient information corresponding to the line is calculated according to the three-phase power ratio corresponding to the line.

3. The method according to claim 2, characterized in that The step of calculating, for each of the lines, the fault additional current information corresponding to the line according to the three-phase current information corresponding to the line, includes: For each phase line of each of the lines, the phase fault additional current information corresponding to the phase line is calculated according to the phase current information collected by the line terminal device on the phase line at a first preset time and a second preset time respectively; the first preset time is the time when the line terminal device collects the phase current information on the phase line after a fault occurs in the distribution network; the second preset time is the time when the line terminal device collects the phase current information on the phase line before a fault occurs in the distribution network; For each of the lines, the phase fault additional current information corresponding to each of the three-phase lines is used as the fault additional current information corresponding to the line.

4. The method according to claim 3, characterized in that The method of calculating, for each of the lines, the additional active power information and the additional reactive power information corresponding to the line according to the fault additional current information and the three-phase voltage information corresponding to the line, comprises: For each phase line of each of the lines, according to the phase fault additional current information corresponding to the phase line and the phase voltage information collected by the line terminal device on the phase line, calculate the phase additional active power information and the phase additional reactive power information corresponding to the phase line; For each of the lines, the phase additional active power information corresponding to each of the three-phase lines is used as the additional active power information corresponding to the line; For each of the lines, the phase additional reactive power information corresponding to each of the three-phase lines is used as the additional reactive power information corresponding to the line; The step of calculating, for each of the lines, a three-phase power ratio corresponding to the line according to a ratio between the additional active power information and the additional reactive power information corresponding to the line, comprises: For each phase line of each of the lines, the phase-added active power information and the phase-added reactive power information corresponding to the phase line are calculated to obtain a phase power ratio corresponding to the phase line; For each of the lines, the phase power ratios corresponding to the three-phase lines are used as the three-phase power ratios corresponding to the line.

5. The method according to claim 4, characterized in that The step of calculating the power quotient information corresponding to each of the lines according to the three-phase power ratio corresponding to the line includes: For each of the lines, according to the phase power ratios corresponding to the three-phase phase lines, a phase line with a maximum phase power ratio is determined; For each of the lines, a phase power ratio corresponding to the phase line with the maximum phase power ratio and the sum of the phase power ratios corresponding to the phase lines of the other two phases are calculated to obtain power quotient information corresponding to the line.

6. The method according to claim 1, characterized in that The determining, based on the three-phase voltage information corresponding to each line in the distribution network, whether the distribution network has a high-resistance grounding fault comprises: Obtaining the rated voltage of the distribution network; Determine, according to the rated voltage, a maximum threshold range corresponding to the maximum phase voltage information of each line in the distribution network, and a minimum threshold range corresponding to the minimum phase voltage information of each line in the distribution network; The three-phase voltage information corresponding to each of the lines is compared with the maximum threshold range and the minimum threshold range respectively, and when the maximum phase voltage information in a line is greater than the maximum threshold range and the minimum phase voltage information in the line is within the minimum threshold range, it is determined that a high-resistance grounding fault exists in the distribution network.

7. The method according to claim 1, characterized in that The sending of the power quotient information corresponding to each of the lines to the fault line selection system so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each of the lines, comprises: The line with the largest power quotient information is determined as a faulty line, so as to complete the detection of the faulty line in the distribution network.

8. A fault line detection device for high-resistance grounding fault in a distribution network, characterized in that: include: An acquisition module, used to acquire three-phase voltage information and three-phase current information corresponding to each line in the distribution network collected by the line terminal device; A judgment module, used to judge whether there is a high-resistance grounding fault in the distribution network according to the three-phase voltage information corresponding to each line in the distribution network; A power quotient information calculation module, configured to calculate the power quotient information corresponding to each line according to the three-phase voltage information and the three-phase current information corresponding to the line if a high-resistance grounding fault exists in the distribution network; The fault line determination module is used to send the power quotient information corresponding to each of the lines to the fault line selection system, so that the fault line selection system determines the fault line in the distribution network according to the power quotient information corresponding to each of the lines.

9. An electronic device, characterized in that: include: A processor and a memory, the memory being used to store a computer program, and the processor being used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store a computer program, the computer program causing a computer to execute the method according to any one of claims 1 to 7.

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