A fault location method, device and equipment for a power collection line of a wind farm and a medium

Abstract

The application discloses a kind of wind farm collection line fault location method, device, equipment and medium.The method includes determining the fault type is two-phase short-circuit fault, obtaining the positive sequence voltage, positive sequence current and negative sequence voltage of collection line protection installation, according to the negative sequence voltage of collection line protection installation, determine the positive sequence voltage of collection line fault place, according to the positive sequence voltage of collection line protection installation, the positive sequence current of collection line protection installation and the positive sequence voltage of collection line fault place, determine the fault distance of collection line, the above technical solution only needs to obtain the electrical data of collection line protection installation, can determine the fault distance of collection line, without occupying communication channel, cost is lower, and it has strong anti transition resistance ability, it is favorable to wind farm collection line fault isolation and recovery, and the safe and stable operation of wind farm.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of relay protection technology, and in particular to a fault location method, device, equipment and medium for wind farm collector lines. Background Technology

[0002] With the increasing prominence of environmental issues and the development of power electronics technology, new energy power generation has rapidly emerged, among which wind power has received widespread attention in recent years, with a clear trend towards offshore applications. Large-capacity offshore wind farms collect power through collector lines to flexible DC converter stations, and then transmit the power to the onshore power grid through DC transmission lines. Both sides of the collector lines are equipped with power electronic converters. When a two-phase short-circuit fault occurs, the current on both sides exhibits characteristics of limited amplitude and controlled phase. Traditional distance protection and online fault location methods are highly susceptible to the influence of transition resistance and require the occupation of communication channels, thus failing to meet the fault location requirements of the collector lines. Summary of the Invention

[0003] This invention provides a method, device, equipment, and medium for fault location of wind farm collector lines. When a two-phase short-circuit fault is determined, the fault distance of the collector line can be determined simply by obtaining the positive sequence voltage, positive sequence current, and negative sequence voltage at the protection installation point of the collector line. This eliminates the need to occupy communication channels, reduces costs, and enables accurate calculation of the fault distance.

[0004] In a first aspect, embodiments of the present invention provide a fault location method for wind farm collector lines, including: when determining that the fault type is a two-phase short-circuit fault, acquiring the positive sequence voltage, positive sequence current and negative sequence voltage at the protection installation point of the collector line;

[0005] The positive sequence voltage at the fault location of the collector line is determined based on the negative sequence voltage at the installation point of the collector line protection.

[0006] The fault distance of the collector line is determined based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault point of the collector line.

[0007] Furthermore, before determining the fault type as a two-phase short-circuit fault, the method also includes:

[0008] Obtain the phase voltage at the installation location of the collector line protection;

[0009] The fault type of the collector line is determined based on the phase voltage at the installation point of the collector line protection.

[0010] Furthermore, determining the fault type of the collector line based on the phase voltage at the installation point of the collector line protection includes:

[0011] According to the fault judgment formula, determine whether the phase voltage at the collector line protection installation point is faulty, and determine the number of faulty phases at the collector line protection installation point; the phase voltage at the collector line protection installation point includes the A-phase voltage, B-phase voltage, and C-phase voltage at the collector line protection installation point, and the fault judgment formula is U. P ≤0.9U N , among which, U P U is the phase voltage at the installation point of the collector line protection. N The rated voltage at the installation point of the collector line protection;

[0012] Based on the number of faulty phases, determine the fault type of the collector line; if there are two faulty phases at the protection installation point of the collector line, the fault type of the collector line is a two-phase short circuit fault; if there is one faulty phase at the protection installation point of the collector line, the fault type of the collector line is a single-phase short circuit fault; if there are three faulty phases at the protection installation point of the collector line, the fault type of the collector line is a three-phase short circuit fault.

[0013] Furthermore, determining the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection includes:

[0014] Determine the normal phase at the installation location of the power collection line protection;

[0015] Based on the negative sequence voltage of the normal phase at the installation location of the collector line protection and the conversion formula, determine the positive sequence voltage of the normal phase at the fault location of the collector line; the conversion formula is as follows: in, This refers to the negative sequence voltage of the normal phase at the installation location of the collector line protection. This is the negative sequence voltage of the normal phase at the fault location in the collector line. This is the positive sequence voltage of the normal phase at the fault location of the collector line.

[0016] Furthermore, determining the fault distance of the collector line based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault location of the collector line includes:

[0017] Obtain the positive sequence impedance of the collector line, and determine the fault distance of the collector line based on the fault location formula, the positive sequence voltage of the normal phase at the protection installation point of the collector line, the positive sequence current of the normal phase at the protection installation point of the collector line, the positive sequence voltage of the normal phase at the fault location of the collector line, and the positive sequence impedance of the collector line; the fault location formula is as follows: in, This refers to the positive sequence voltage of the normal phase at the installation location of the collector line protection. This represents the positive sequence voltage of the normal phase at the fault location in the collector line. Z is the positive sequence current of the normal phase at the installation point of the collector line protection, Z is the positive sequence impedance of the collector line, and α is the fault distance of the collector line.

[0018] Furthermore, after obtaining the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection, the method further includes:

[0019] The positive sequence voltage, positive sequence current, and negative sequence voltage at the installation point of the collector line protection are filtered and converted according to their formats.

[0020] Furthermore, after determining the fault distance of the collector line based on the positive sequence voltage at the collector line protection installation point, the positive sequence current at the collector line protection installation point, and the positive sequence voltage at the collector line fault location, the method further includes:

[0021] The time is differentially divided based on the fault distance to obtain differential data;

[0022] Determine whether the difference data is less than a preset value;

[0023] If the differential data is less than the preset value, the corresponding fault distance is output;

[0024] If the differential data is greater than the preset value, continue to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection and determine the fault distance of the collector line.

[0025] Secondly, embodiments of the present invention also provide a fault location device for wind farm collector lines, the fault location device comprising:

[0026] The acquisition module is used to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection when the fault type is determined to be a two-phase short-circuit fault.

[0027] The determination module is used to determine the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection.

[0028] The ranging module is used to determine the fault distance of the collector line based on the positive sequence voltage at the collector line protection installation point, the positive sequence current at the collector line protection installation point, and the positive sequence voltage at the collector line fault location.

[0029] Thirdly, embodiments of the present invention also provide a fault location device, the fault location device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to execute the fault location method described in any embodiment of the present invention.

[0030] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions, which are used to cause a processor to execute and implement any of the fault location methods described in the embodiments of the present invention.

[0031] This invention, after determining the fault type to be a two-phase short-circuit fault, acquires the positive-sequence voltage, positive-sequence current, and negative-sequence voltage at the collector line protection installation point. Based on the negative-sequence voltage at the collector line protection installation point, the positive-sequence voltage at the collector line fault location is determined. Then, based on the positive-sequence voltage, positive-sequence current, and positive-sequence voltage at the collector line protection installation point, the fault distance of the collector line is determined. This technical solution only requires the electrical data from the collector line protection installation point, without occupying a communication channel, resulting in lower costs. Furthermore, it eliminates the influence of transition resistance on fault location in principle, possessing strong resistance to transition resistance. This is beneficial for the isolation and recovery of collector line faults in wind farms, as well as the safe and stable operation of wind farms. It solves the problem that traditional distance protection and online fault location methods in the prior art are easily affected by transition resistance and require the occupation of communication channels, thus failing to meet the fault location requirements of collector lines. Attached Figure Description

[0032] Figure 1 A flowchart of a fault location method for wind farm collector lines provided in Embodiment 1 of the present invention;

[0033] Figure 2 A flowchart of another method for fault location of wind farm collector lines provided in Embodiment 2 of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of a fault location device for a wind farm collector line provided in Embodiment 3 of the present invention;

[0035] Figure 4 This is a structural schematic diagram of a fault location device provided in Embodiment 4 of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0038] Example 1

[0039] Figure 1 This is a flowchart of a fault location method for wind farm collector lines according to Embodiment 1 of the present invention. This embodiment is applicable to situations where online fault location of wind farm collector lines is highly susceptible to the influence of transition resistance and requires the occupation of communication channels, thus failing to meet the fault location requirements of the collector lines. This method can be executed by the fault location device provided in this embodiment of the present invention, which can be implemented in software and / or hardware. This device can be configured in the fault location equipment provided in this embodiment of the present invention.

[0040] The wind farm collector line of this invention has a wind turbine converter and a flexible DC converter on both sides, and both the wind turbine converter and the flexible DC converter adopt a negative sequence current suppression control strategy. The fault location method specifically includes:

[0041] S110. When the fault type is determined to be a two-phase short-circuit fault, obtain the positive sequence voltage, positive sequence current and negative sequence voltage at the installation point of the collector line protection.

[0042] For example, the fault type may include single-phase short-circuit fault, two-phase short-circuit fault, and three-phase short-circuit fault. When the fault type is determined to be a two-phase short-circuit fault, electrical data at the collector line protection installation location is collected in real time using a current transformer device installed at the collector line protection installation location. This electrical data includes the positive-sequence voltage, positive-sequence current, and negative-sequence voltage at the collector line protection installation location. Specifically, since the collector line includes phases A, B, and C, the acquired electrical data includes the positive-sequence voltage, positive-sequence current, and negative-sequence voltage of phase A, phase B, and phase C at the collector line protection installation location.

[0043] S120. Determine the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection.

[0044] Specifically, since one side of the collector line is a wind turbine converter and the other side is a flexible DC converter, and both the wind turbine converter and the flexible DC converter adopt a negative sequence current suppression control strategy, when a two-phase fault occurs in the collector line, neither side outputs negative sequence current, making the negative sequence current in the collector line approximately zero. Consequently, the negative sequence voltage at the collector line protection installation point is equal to the negative sequence voltage at the collector line fault point. Furthermore, since the positive sequence impedance of the collector line does not divide the voltage, the negative sequence voltage at the collector line fault point is the same as the positive sequence voltage at the collector line fault point. Therefore, the positive sequence voltage at the collector line fault point can be directly obtained through the negative sequence voltage at the collector line protection installation point, without needing to occupy the communication channel to obtain the positive sequence voltage at the collector line fault point, reducing costs. In principle, it eliminates the influence of transition resistance on fault location, making it suitable for complex fault environments of submarine cables.

[0045] S130. Determine the fault distance of the collector line based on the positive sequence voltage at the collector line protection installation point, the positive sequence current at the collector line protection installation point, and the positive sequence voltage at the collector line fault location.

[0046] After obtaining the positive-sequence voltage at the fault location of the collector line through the negative-sequence voltage at the collector line protection installation point, the positive-sequence voltage at the fault location, along with the positive-sequence voltage and positive-sequence current at the collector line protection installation point obtained from the instrument transformer, are substituted into the fault location formula to determine the fault distance of the collector line. The fault distance of the collector line can be understood as the distance between the fault location and the collector line protection installation point, or as the percentage of the collector line where the fault occurs, such as at 20%, 50%, 85%, or 99%. Therefore, in determining the fault distance of the collector line in this application, the data used are all positive-sequence voltage, negative-sequence voltage, and positive-sequence current at the collector line protection installation point obtained from the instrument transformer, i.e., local electrical data is used, eliminating the need to occupy communication channels, resulting in low modification costs, and fundamentally eliminating the influence of transition resistance on fault location.

[0047] In summary, after determining that the fault type is a two-phase short-circuit fault, this embodiment of the invention obtains the positive-sequence voltage, positive-sequence current, and negative-sequence voltage at the installation point of the collector line protection. Based on the negative-sequence voltage at the installation point, the positive-sequence voltage at the fault location is determined. Then, based on the positive-sequence voltage, positive-sequence current, and positive-sequence voltage at the fault location, the fault distance of the collector line is determined. This method uses local electrical data, does not require the use of communication channels, has low modification costs, and eliminates the influence of transition resistance on fault location in principle. It can be applied to the complex fault environment of submarine cables, has strong resistance to transition resistance, and is beneficial for the isolation and recovery of collector line faults in wind farms, as well as the safe and stable operation of wind farms.

[0048] Example 2

[0049] Figure 2 A flowchart of another method for fault location of wind farm collector lines provided in Embodiment 2 of the present invention is shown below. Figure 2 The method includes:

[0050] S210. Obtain the phase voltage at the installation point of the collector line protection, and determine the fault type of the collector line based on the phase voltage at the installation point of the collector line protection.

[0051] For example, by using a current transformer device installed at the point of installation of the collector line protection, the phase voltage at the point of installation is collected in real time. This phase voltage includes the phase voltages of phase A, phase B, and phase C at the point of installation. The fault type of the collector line is then determined based on these phase voltages.

[0052] Specifically, the fault diagnosis formula is U P ≤0.9U N , among which, U P U is the phase voltage at the installation point of the collector line protection. N The rated voltage at the installation point of the collector line protection is used as the reference. If the phase voltage at the installation point is less than or equal to 90% of the rated voltage, then a fault is identified at that phase voltage, and the phase voltage at that fault is recorded as the faulty phase. Then, the phase voltages of phases A, B, and C at the installation point are compared with the rated voltage of the collector line protection to determine the number of faulty phases at that installation point.

[0053] The type of fault in the relay line is determined based on the number of faulty phases. Specifically, if there are two faulty phases at the installation point of the collector line protection, the fault type is a two-phase short circuit fault. For example, according to the fault judgment formula, if phases A and B, or phases B and C, are faulty at the installation point, the fault type is determined to be a two-phase short circuit fault. If there is only one faulty phase at the installation point of the collector line protection, the fault type is a single-phase short circuit fault. For example, according to the fault judgment formula, if phases A, B, or C are faulty at the installation point, the fault type is determined to be a single-phase short circuit fault. If there are three faulty phases at the installation point of the collector line protection, the fault type is a three-phase short circuit fault. For example, according to the fault judgment formula, if phases A, B, and C are all faulty at the installation point, the fault type is determined to be a three-phase short circuit fault. Furthermore, by obtaining the phase voltage at the installation point of the collector line protection and based on the fault judgment formula, two-phase short-circuit faults can be quickly and accurately identified, thus improving the accuracy of fault location.

[0054] It should be noted that the embodiments of the present invention are only applicable to fault location for two-phase short-circuit faults. When the fault type of the collector line is determined to be a single-phase short-circuit fault or a three-phase short-circuit fault, the phase voltage at the protection installation point of the collector line is collected again, and the fault type of the collector line is determined again, until the fault type of the collector line is a two-phase short-circuit fault.

[0055] S220. When the fault type is determined to be a two-phase short-circuit fault, obtain the positive sequence voltage, positive sequence current and negative sequence voltage at the installation point of the collector line protection.

[0056] S230: Filter and convert the positive sequence voltage, positive sequence current and negative sequence voltage at the installation point of the collector line protection.

[0057] Specifically, after collecting the positive-sequence voltage, positive-sequence current, and negative-sequence voltage at the installation point of the power line protection, the data center can filter the collected electrical data to eliminate data interference and ensure the accuracy of the measurement results. Furthermore, the data center can convert the analog electrical data into digital analog data, which can then be substituted into formulas to calculate the fault distance.

[0058] It should be noted that the electrical data also includes the phase voltage at the installation point of the collector line protection. The data center performs filtering and format conversion on the phase voltage at the installation point of the collector line protection.

[0059] S240. Determine the normal phase at the installation location of the collector line protection. Based on the negative sequence voltage and conversion formula of the normal phase at the installation location of the collector line protection, determine the positive sequence voltage of the normal phase at the fault location of the collector line.

[0060] Specifically, once the fault type is determined to be a two-phase short-circuit fault, that is, if any two of the A, B, and C phases at the collector line protection installation point have a short-circuit fault, then the two phases with the short-circuit fault are the fault phases, and the other phase is the normal phase. For example, if the A and B phases at the collector line protection installation point have a fault, then the A and B phases are the fault phases, and the C phase is the normal phase.

[0061] Furthermore, since one side of the collector line is a wind turbine converter and the other side is a flexible DC converter, and both the wind turbine converter and the flexible DC converter employ a negative sequence current suppression control strategy, no negative sequence current is output from either side of the collector line when a two-phase fault occurs. This makes the negative sequence current in the collector line approximately zero. Consequently, the negative sequence voltage of the normal phase at the collector line protection installation point is equal to the negative sequence voltage of the normal phase at the fault location. Also, since the positive sequence impedance of the collector line does not divide the voltage, the negative sequence voltage of the normal phase at the fault location is the same as the positive sequence voltage of the normal phase at the fault location. In other words, there exists a relationship between these three factors. The conversion formula, where, This refers to the negative sequence voltage of the normal phase at the installation location of the collector line protection. This is the negative sequence voltage of the normal phase at the fault location in the collector line. This refers to the positive sequence voltage of the normal phase at the fault location of the collector line. Furthermore, based on the negative sequence voltage of the normal phase at the collector line protection installation location collected by the current transformer device, the positive sequence voltage of the normal phase at the fault location can be directly obtained. This eliminates the need to occupy a communication channel to acquire the positive sequence voltage of the normal phase at the fault location, reducing costs. It also eliminates the influence of transition resistance on fault location in principle, making it suitable for complex fault environments in submarine cables.

[0062] 250. Obtain the positive sequence impedance of the collector line, and determine the fault distance of the collector line based on the fault location formula, the positive sequence voltage of the normal phase at the collector line protection installation point, the positive sequence current of the normal phase at the collector line protection installation point, the positive sequence voltage of the normal phase at the fault location of the collector line, and the positive sequence impedance of the collector line.

[0063] Specifically, the fault location formula is: in, This refers to the positive sequence voltage of the normal phase at the installation location of the collector line protection. This represents the positive sequence voltage of the normal phase at the fault location in the collector line. Let Z be the positive-sequence current of the normal phase at the installation point of the collector line protection, Z be the positive-sequence impedance of the collector line, and α be the fault distance of the collector line. The positive-sequence impedance of the collector line is obtained through the data center. Substituting the positive-sequence voltage of the normal phase at the installation point of the collector line protection, the positive-sequence current of the normal phase at the installation point of the collector line protection, the positive-sequence voltage of the normal phase at the fault location of the collector line, and the positive-sequence impedance of the collector line obtained in the above steps into the fault location formula, the fault distance of the collector line can be directly obtained.

[0064] It should be noted that, due to Therefore, the fault location formula can be transformed into Furthermore, it becomes clearer that the fault distance of the collector line can be obtained simply by collecting electrical data from the installation location of the collector line protection. This eliminates the need to occupy communication channels, resulting in low modification costs. In principle, it eliminates the influence of transition resistance on fault location, making it suitable for the complex fault environment of submarine cables and possessing strong resistance to transition resistance.

[0065] S260. Divide the time according to the fault distance to obtain differential data; determine whether the differential data is less than the preset value; if the differential data is less than the preset value, output the corresponding fault distance; if the differential data is greater than the preset value, continue to obtain the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection and determine the fault distance of the collector line.

[0066] Specifically, after obtaining the fault distance of the collector line, it is necessary to verify the accuracy of the fault distance. For example, the calculated fault distance is differentially divided by time to obtain differential data. The differential data can be five consecutive sampling points. If the differential data is less than a preset value, that is, the difference values ​​of the five consecutive sampling points are all less than the preset value, then the obtained fault distance is considered to be relatively accurate, and the fault distance is output. If the differential data is greater than the preset value, that is, the difference values ​​of the five consecutive sampling points are greater than the preset value, then the obtained fault distance is considered to be inaccurate. Then, the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation point of the collector line protection are re-acquired, and the fault distance is calculated again according to steps S210-S250 until the difference values ​​of the five consecutive sampling points are all less than the preset value, where the preset value can be 0.1 pu / ms.

[0067] In summary, this embodiment of the invention determines the fault type of the collector line by acquiring the phase voltage at the protection installation point. When the fault type is determined to be a two-phase short-circuit fault, the normal phase at the protection installation point is identified. Based on the negative sequence voltage and conversion formula of the normal phase at the protection installation point, the positive sequence voltage of the normal phase at the fault location is determined. Then, the positive sequence impedance of the collector line is acquired. Based on the fault location formula, the positive sequence voltage of the normal phase at the protection installation point, the positive sequence current of the normal phase at the protection installation point, the positive sequence voltage of the normal phase at the fault location, and the positive sequence impedance of the collector line, the fault distance of the collector line is determined, and the accuracy of the fault distance is verified. The entire process uses local electrical data, does not require the use of communication channels, has low modification costs, and eliminates the influence of transition resistance on fault location in principle. It can be applied to the complex fault environment of submarine cables, has strong resistance to transition resistance, and is beneficial for the isolation and recovery of collector line faults in wind farms, as well as the safe and stable operation of wind farms.

[0068] Example 3

[0069] Figure 3 This is a schematic diagram of a fault location device for wind farm collector lines according to Embodiment 3 of the present invention. This embodiment is applicable to situations where online fault location of wind farm collector lines is highly susceptible to the influence of transition resistance and requires the occupation of communication channels, thus failing to meet the fault location requirements of the collector lines. The specific structure of the compensation device is as follows:

[0070] The acquisition module 30 is used to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection when the fault type is determined to be a two-phase short circuit fault.

[0071] The determination module 31 is used to determine the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection.

[0072] The ranging module 32 is used to determine the fault distance of the collector line based on the positive sequence voltage at the collector line protection installation point, the positive sequence current at the collector line protection installation point, and the positive sequence voltage at the collector line fault point.

[0073] It also includes a judgment module for obtaining the phase voltage at the installation point of the collector line protection; and for judging the fault type of the collector line based on the phase voltage at the installation point of the collector line protection.

[0074] The judgment module is specifically used to determine whether the phase voltage at the collector line protection installation point is faulty, based on the fault judgment formula, and to determine the number of faulty phases at the collector line protection installation point. The phase voltage at the collector line protection installation point includes the A-phase voltage, B-phase voltage, and C-phase voltage at the collector line protection installation point. The fault judgment formula is U... P ≤0.9U N , among which, U P U is the phase voltage at the installation point of the collector line protection. N The rated voltage at the installation point of the collector line protection;

[0075] The fault type of the collector line is determined based on the number of faulty phases. If there are two faulty phases at the installation point of the collector line protection, the fault type of the collector line is a two-phase short circuit fault. If there is one faulty phase at the installation point of the collector line protection, the fault type of the collector line is a single-phase short circuit fault. If there are three faulty phases at the installation point of the collector line protection, the fault type of the collector line is a three-phase short circuit fault.

[0076] Module 31 is specifically used to determine the normal phase at the installation location of the collector line protection. Based on the negative sequence voltage of the normal phase at the installation location and the conversion formula, it determines the positive sequence voltage of the normal phase at the fault location of the collector line. The conversion formula is as follows: in, This refers to the negative sequence voltage of the normal phase at the installation location of the collector line protection. This is the negative sequence voltage of the normal phase at the fault location in the collector line. This is the positive sequence voltage of the normal phase at the fault location of the collector line.

[0077] The fault location module 32 is specifically used to obtain the positive sequence impedance of the collector line. Based on the fault location formula, the positive sequence voltage of the normal phase at the collector line protection installation point, the positive sequence current of the normal phase at the collector line protection installation point, the positive sequence voltage of the normal phase at the fault location of the collector line, and the positive sequence impedance of the collector line, it determines the fault distance of the collector line. The fault location formula is as follows: in, This refers to the positive sequence voltage of the normal phase at the installation location of the collector line protection. This represents the positive sequence voltage of the normal phase at the fault location in the collector line. Z is the positive sequence current of the normal phase at the installation point of the collector line protection, Z is the positive sequence impedance of the collector line, and α is the fault distance of the collector line.

[0078] The fault location device also includes a differential module, which is used to differentiate time based on the fault distance to obtain differential data; determine whether the differential data is less than a preset value; if the differential data is less than the preset value, output the corresponding fault distance; if the differential data is greater than the preset value, continue to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection and determine the fault distance of the collector line.

[0079] In summary, the embodiments of the present invention include an acquisition module for acquiring the positive-sequence voltage, positive-sequence current, and negative-sequence voltage at the installation point of the collector line protection when the fault type is determined to be a two-phase short-circuit fault; a determination module for determining the positive-sequence voltage at the fault location of the collector line based on the negative-sequence voltage at the installation point of the collector line protection; and a distance measurement module for determining the fault distance of the collector line based on the positive-sequence voltage, positive-sequence current, and positive-sequence voltage at the installation point of the collector line protection. This approach utilizes only the electrical data from the collector line protection installation point, eliminating the need to occupy communication channels, resulting in lower costs. Furthermore, it eliminates the influence of transition resistance on fault distance measurement in principle, exhibiting strong resistance to transition resistance. This is beneficial for the isolation and recovery of collector line faults in wind farms, as well as the safe and stable operation of wind farms. It solves the problems of existing distance protection and online fault distance measurement methods being easily affected by transition resistance and requiring communication channels, thus failing to meet the requirements for collector line fault distance measurement.

[0080] Example 4

[0081] Figure 4 This is a schematic diagram of a fault location device according to Embodiment 4 of the present invention. The fault location device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The fault location device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0082] like Figure 4As shown, the fault location device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the fault location device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0083] Multiple components in the fault location device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, optical disk, etc.; and a communication unit 19, such as a network card, modem, wireless transceiver, etc. The communication unit 19 allows the fault location device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0084] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above.

[0085] In some embodiments, the fault location method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the fault location device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the compensation method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the compensation method by any other suitable means (e.g., by means of firmware).

[0086] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0087] Example 5

[0088] Embodiment 5 of the present invention also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform a fault location method for wind farm collector lines, the method comprising:

[0089] When the fault type is determined to be a two-phase short-circuit fault, obtain the positive sequence voltage, positive sequence current and negative sequence voltage at the installation point of the collector line protection;

[0090] Determine the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation point of the collector line protection.

[0091] The fault distance of the collector line is determined based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault location of the collector line.

[0092] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the method operations described above, but can also perform related operations in the fault location method for wind farm collection lines provided in any embodiment of the present invention.

[0093] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0094] It is worth noting that in the embodiments of the search device described above, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0095] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A fault location method for wind farm collector lines, characterized in that, include: When the fault type is determined to be a two-phase short-circuit fault, obtain the positive sequence voltage, positive sequence current and negative sequence voltage at the installation point of the collector line protection; The positive sequence voltage at the fault location of the collector line is determined based on the negative sequence voltage at the installation point of the collector line protection. The fault distance of the collector line is determined based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault point of the collector line. Determining the fault distance of the collector line based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault location of the collector line includes: Obtain the positive sequence impedance of the collector line, and determine the fault distance of the collector line based on the fault location formula, the positive sequence voltage of the normal phase at the protection installation point of the collector line, the positive sequence current of the normal phase at the protection installation point of the collector line, the positive sequence voltage of the normal phase at the fault location of the collector line, and the positive sequence impedance of the collector line; the fault location formula is as follows: ,in, This refers to the positive sequence voltage of the normal phase at the installation location of the collector line protection. This represents the positive sequence voltage of the normal phase at the fault location in the collector line. Z represents the positive sequence current of the normal phase at the installation point of the collector line protection, and Z represents the positive sequence impedance of the collector line. This refers to the fault distance of the collector line.

2. The fault location method according to claim 1, characterized in that, Before determining the fault type as a two-phase short-circuit fault, the method further includes: Obtain the phase voltage at the installation location of the collector line protection; The fault type of the collector line is determined based on the phase voltage at the installation point of the collector line protection.

3. The fault location method according to claim 2, characterized in that, The step of determining the fault type of the collector line based on the phase voltage at the installation point of the collector line protection includes: According to the fault diagnosis formula, determine whether the phase voltage at the collector line protection installation point is faulty, and determine the number of faulty phases at the collector line protection installation point; the phase voltage at the collector line protection installation point includes the A-phase voltage, B-phase voltage, and C-phase voltage at the collector line protection installation point, and the fault diagnosis formula is as follows: ,in, The phase voltage at the installation point of the collector line protection. The rated voltage at the installation point of the collector line protection; Based on the number of faulty phases, determine the fault type of the collector line; if there are two faulty phases at the protection installation point of the collector line, the fault type of the collector line is a two-phase short circuit fault; if there is one faulty phase at the protection installation point of the collector line, the fault type of the collector line is a single-phase short circuit fault; if there are three faulty phases at the protection installation point of the collector line, the fault type of the collector line is a three-phase short circuit fault.

4. The fault location method according to claim 3, characterized in that, Determining the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection includes: Determine the normal phase at the installation location of the power collection line protection; Based on the negative sequence voltage of the normal phase at the installation location of the collector line protection and the conversion formula, determine the positive sequence voltage of the normal phase at the fault location of the collector line; the conversion formula is as follows: = ,in, This refers to the negative sequence voltage of the normal phase at the installation location of the collector line protection. This is the negative sequence voltage of the normal phase at the fault location in the collector line. This is the positive sequence voltage of the normal phase at the fault location of the collector line.

5. The fault location method according to claim 1, characterized in that, After obtaining the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection, the method further includes: The positive sequence voltage, positive sequence current, and negative sequence voltage at the installation point of the collector line protection are filtered and converted according to their formats.

6. The fault location method according to claim 1, characterized in that, After determining the fault distance of the collector line based on the positive sequence voltage at the collector line protection installation point, the positive sequence current at the collector line protection installation point, and the positive sequence voltage at the collector line fault location, the method further includes: The time is differentially divided based on the fault distance to obtain differential data; Determine whether the difference data is less than a preset value; If the differential data is less than the preset value, the corresponding fault distance is output; If the differential data is greater than the preset value, continue to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection and determine the fault distance of the collector line.

7. A fault location device for wind farm collector lines, characterized in that, include: The acquisition module is used to acquire the positive sequence voltage, positive sequence current, and negative sequence voltage at the installation location of the collector line protection when the fault type is determined to be a two-phase short-circuit fault. The determination module is used to determine the positive sequence voltage at the fault location of the collector line based on the negative sequence voltage at the installation location of the collector line protection. The ranging module is used to determine the fault distance of the collector line based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault point of the collector line. Determining the fault distance of the collector line based on the positive sequence voltage at the installation point of the collector line protection, the positive sequence current at the installation point of the collector line protection, and the positive sequence voltage at the fault location of the collector line includes: Obtain the positive sequence impedance of the collector line, and determine the fault distance of the collector line based on the fault location formula, the positive sequence voltage of the normal phase at the protection installation point of the collector line, the positive sequence current of the normal phase at the protection installation point of the collector line, the positive sequence voltage of the normal phase at the fault location of the collector line, and the positive sequence impedance of the collector line; the fault location formula is as follows: ,in, This refers to the positive sequence voltage of the normal phase at the installation location of the collector line protection. This represents the positive sequence voltage of the normal phase at the fault location in the collector line. Z represents the positive sequence current of the normal phase at the installation point of the collector line protection, and Z represents the positive sequence impedance of the collector line. This refers to the fault distance of the collector line.

8. A fault location device, characterized in that, The fault location device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the fault location method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the fault location method according to any one of claims 1-6.

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