Wind farm collection line fault location method based on compressed sensing multi-reconstruction

Abstract

The application relates to the technical field of power system relay protection, in particular to a wind farm power collection line fault positioning method based on compressed sensing multi-reconstruction. An underdetermined equation set is constructed by using the negative sequence voltage component in three-phase voltage, a node impedance matrix and current information during a fault, the fault current nodes in the underdetermined equation set are reconstructed by using a compressed sensing algorithm multiple times, the final fault area is positioned in multiple times, the fault positioning of a complex wind farm power collection line is realized under the condition that a small amount of measuring points are collected, and too many measuring devices are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system relay protection, in particular to a wind farm collection line fault positioning method based on compressed sensing multi-reconstruction. BACKGROUND

[0002] The wind farm collection line refers to the power line connected by multiple wind turbine generators, and the fault of the wind farm collection line will cause the interruption of power transmission, thereby affecting the overall efficiency of the wind farm.

[0003] The traditional mainstream fault diagnosis method often adopts a double-end measurement point positioning method, installs a traveling wave detection device at the A and B ends of the line, synchronously records the times t1 and t2 when the traveling wave reaches the A and B ends, and according to the known full length L of the line and the fixed traveling wave speed v of current propagation, the distance between the fault point C and the A / B end can be calculated, thereby positioning the exact location of the fault occurrence point.

[0004] However, as the scale of the wind farm increases, the layout of the wind farm collection line tends to be complex and the length gradually increases, multiple measurement points are required to realize fault positioning, which increases the positioning difficulty and positioning response time of the fault. In view of this, a new wind farm collection line fault positioning method is needed to realize the rapid positioning of the fault of the complex wind power circuit system under the condition of limited measurement point times. SUMMARY

[0005] The main purpose of the present application is to provide a wind farm collection line fault positioning method based on compressed sensing multi-reconstruction, which aims to solve the problem of how to rapidly position the fault of the complex wind power circuit system under the condition of limited measurement point times.

[0006] To achieve the above-mentioned purpose, the present application provides a wind farm collection line fault positioning method based on compressed sensing multi-reconstruction, which comprises:

[0007] S10, acquiring a plurality of first negative sequence voltage components in the three-phase voltage collected when a fault is detected in the wind farm collection line, a plurality of current signals collected, and a node impedance matrix constructed by the line parameters in the current wind farm collection line;

[0008] S20, constructing a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix and the current signal, reconstructing the negative sequence fault current node in the first underdetermined equation set through a compressed sensing algorithm, and taking the two nodes with the highest occurrence frequency in the negative sequence fault current node as the first fault node;

[0009] S30, calculating a negative sequence voltage component of an adjacent node of the first fault node as a second negative sequence voltage component, determining a corrected negative sequence voltage component according to the second negative sequence voltage component and the first negative sequence voltage component, updating the node impedance matrix according to a line parameter in the current wind farm collection line, constructing a second underdetermined equation set according to the corrected negative sequence voltage component, the updated node impedance matrix and the current signal, and reconstructing a second negative sequence fault current node in the second underdetermined equation set through a compressed sensing algorithm, taking two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes;

[0010] S40, calculating a third negative sequence voltage component in a fault section formed by the second fault nodes, and updating the node impedance matrix again according to a line parameter in the current wind farm collection line, constructing a third underdetermined equation set according to the third negative sequence voltage component, the node impedance matrix updated again and the current signal, and reconstructing a third negative sequence fault current node in the third underdetermined equation set through a compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the third negative sequence fault current node as target fault nodes.

[0011] Optionally, in the S30, the calculation expression of the second negative sequence voltage component is:

[0012]

[0013] wherein, Vj represents the negative sequence voltage component of the adjacent node j, Lj represents the line length of the node and the node . Z represents the impedance per unit length of the line; Y represents the admittance per unit length of the line.

[0014] Optionally, in the S40, the step of calculating the third negative sequence voltage component in the fault section formed by the second fault nodes specifically comprises:

[0015] setting the total length of the fault section as x, and calculating a fault voltage value at 0.3x and a fault voltage value at 0.7x in the fault section respectively;

[0016] taking the negative sequence voltage decomposed from the fault voltage value at 0.3x and the negative sequence voltage decomposed from the fault voltage value at 0.7x as the third negative sequence voltage component.

[0017] The expression of the first underdetermined equation set is:

[0018]

[0019] M is the number of nodes of the first negative sequence voltage component, is the first negative sequence voltage component, is the node impedance matrix, is the current signal.

[0020] Optionally, the second underdetermined equation set is expressed as:

[0021]

[0022] M+T is the sum of the number of nodes of the first negative sequence voltage component and the second negative sequence voltage component, is the corrected negative sequence voltage component, is the updated node impedance matrix, is the current signal.

[0023] Optionally, the third underdetermined equation set is expressed as:

[0024]

[0025] x is the number of third negative sequence voltage components, is the third negative sequence voltage component, is the re-updated node impedance matrix, is the current signal.

[0026] In addition, to achieve the above-mentioned purpose, the application also provides a wind farm power collection line fault positioning device, which comprises:

[0027] A collection module is configured to acquire a plurality of first negative sequence voltage components in three-phase voltage collected when a fault is detected in a wind farm power collection line, a plurality of current signals, and a node impedance matrix constructed by a line parameter in the wind farm power collection line at present;

[0028] A primary reconstruction fault positioning module is configured to construct a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix, and the current signal, reconstruct a negative sequence fault current node in the first underdetermined equation set by a compressed sensing algorithm, take two nodes with the highest frequency in the negative sequence fault current node as first fault nodes, calculate a negative sequence voltage component of a neighboring node of the first fault node as a second negative sequence voltage component;

[0029] a secondary reconstruction fault location module, configured to determine a corrected negative sequence voltage component according to the second negative sequence voltage component and the negative sequence voltage component, update the node impedance matrix according to current line parameters in the wind farm collection line, construct a second underdetermined equation set according to the corrected negative sequence voltage component and the updated node impedance matrix, and reconstruct a second negative sequence fault current node in the second underdetermined equation set by a compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes;

[0030] a tertiary reconstruction fault location module, configured to calculate a third negative sequence voltage component in a fault section constituted by the second fault nodes, and update the node impedance matrix again according to current line parameters in the wind farm collection line, construct a third underdetermined equation set according to the third negative sequence voltage component and the node impedance matrix updated again, and reconstruct a third negative sequence fault current node in the third underdetermined equation set by the compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the third negative sequence fault current node as target fault nodes.

[0031] In addition, to achieve the above object, the present application further provides a computer system, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the wind farm collection line fault location method based on compressed sensing multi-reconstruction according to any one of the above.

[0032] In addition, to achieve the above object, the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program, when executed by a processor, implements the steps of the wind farm collection line fault location method based on compressed sensing multi-reconstruction.

[0033] The present application has at least the following beneficial effects:

[0034] 1. The underdetermined equation set is constructed by the negative sequence voltage component in the three-phase voltage during the fault, the node impedance matrix and the current information, the fault current nodes in the underdetermined equation set are reconstructed by the compressed sensing algorithm for multiple times, the final fault area is located in multiple times, the fault location of the complex wind farm collection line is realized under the condition of a small amount of measurement points, and the investment of excessive measurement devices is avoided.

[0035] 2. The dependence on high sampling frequency equipment is broken, the demand for complex electrical information is simplified, the required data amount is reduced, and the system configuration is more flexible. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1A schematic diagram of a wind farm collection line model built in PSCAD / EMTDC software involved in the embodiments of the present application;

[0037] Figure 2 A flowchart of a wind farm collection line fault location method based on compressed sensing multiple reconstruction involved in the embodiments of the present application;

[0038] Figure 3 A preliminary fault location schematic diagram involved in the embodiments of the present application;

[0039] Figure 4 A secondary fault location schematic diagram involved in the embodiments of the present application;

[0040] Figure 5 A tertiary fault location schematic diagram involved in the embodiments of the present application;

[0041] Figure 6 A wind farm collection line fault location device involved in the embodiments of the present application;

[0042] Figure 7 A schematic diagram of the hardware operating environment of a computer system involved in the embodiments of the present application.

[0043] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0044] In order to better understand the above technical solutions, the exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] First embodiment

[0046] Referring to Figure 1 The wind farm collection line model built in PSCAD / EMTDC software in the present embodiment is shown in the schematic diagram, there are 3 collection lines, 23 wind turbines, the sampling rate is 4 kHz, a two-phase short circuit ground fault is set between nodes 4-5 in L1 collection line, the fault position is 1300 m away from node 4, L1 has six wind turbines, L2 has eleven wind turbines, and L3 has six wind turbines. The measurement points are distributed at the bus, the end of the collection line and 13 nodes, a total of 5 measurement points. The entire system has 24 nodes. The black triangles in the figure are the installation positions of the measurement points.

[0047] Based on the model architecture, referring to Figure 2The embodiment provides a flowchart of a wind farm power collection line fault positioning method based on compressed sensing multi-reconstruction, and the method comprises the following steps:

[0048] S10, acquiring a plurality of first negative sequence voltage components in three-phase voltage collected when a fault is detected in a wind farm power collection line, a plurality of current signals collected, and a node impedance matrix constructed by a line parameter in the wind farm power collection line at present;

[0049] In the embodiment, the circuit parameter acquisition device is installed at each preset position node in the wind farm power collection line, three-phase voltage, current signals and other circuit data collected by the circuit parameter acquisition device are acquired, when a fault occurs in the power collection line, the device can detect that the three-phase voltage and the current signal jump, the three-phase voltage and the current signal recorded by the device at this time are acquired, and the negative sequence voltage component (also referred to as a negative sequence voltage sag vector) in the three-phase voltage is decomposed as the first negative sequence voltage component.

[0050] In the embodiment, the node impedance matrix (Node Impedance Matrix, referred to as Z-bus) is used to describe the impedance relationship between each node (bus) in the network, and is an N*N symmetric matrix, wherein The element in the matrix represents mutual impedance between node i and node j (voltage change of node i when a unit current is injected into node j), and the diagonal element is the self-impedance of node i (i.e. the voltage change of node i when a unit current is injected into node i).

[0051] Exemplarily, the node impedance matrix is constructed based on the topology structure and the line parameter of the wind farm power collection line, and the specific expression is as follows:

[0052]

[0053] In the formula, Z is the node impedance matrix, the subscript is impedance between nodes, for example, F1 is impedance between a fault point and node 1, and the superscript 2 is not square, but a negative sequence component.

[0054] In some embodiments, the negative sequence voltage component in the three-phase voltage is decomposed by using the symmetrical component method, and exemplarily, the expression of the negative sequence voltage component is as follows:

[0055]

[0056] In the formula, , , are positive, negative and zero sequence voltages respectively; , , are abc three-phase voltages; is a rotation factor.

[0057] S20, constructing a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix and the current signal, reconstructing a negative sequence fault current node in the first underdetermined equation set through a compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the negative sequence fault current node as first fault nodes;

[0058] In this step, a fault determination is made on the faulted wind farm collection line. First, an underdetermined equation set is established according to the first negative sequence voltage component, the node impedance matrix and the current signal in S10 as a first underdetermined equation set.

[0059] It should be noted that the underdetermined equation set refers to a case where the number of equations is less than the number of unknowns, and there are infinite sets of solutions that are not unique. Through the compressed sensing algorithm (Compressed Sensing, CS), a negative sequence fault current vector is reconstructed from a small amount of observation data through sparsity prior and nonlinear optimization. As long as the target signal is sufficiently sparse, the compressed sensing technology can accurately reconstruct a unique solution vector.

[0060] In some embodiments, the expression of the first underdetermined equation set is as follows:

[0061]

[0062] In the formula, M is the number of nodes of the first negative sequence voltage component, is the first negative sequence voltage component, is the node impedance matrix, is the current signal.

[0063] Exemplarily, referring to the preliminary fault location diagram shown in FIG. 1, the vertically protruding parts in the figure are two nodes with the highest occurrence frequency in the negative sequence fault current node, which are taken as the first fault nodes. In addition, the area formed between the two first fault nodes is the preliminary fault area locked after the preliminary determination. Figure 3

[0064] S30, calculating a negative sequence voltage component of a node adjacent to the first fault node as a second negative sequence voltage component, determining a corrected negative sequence voltage component according to the second negative sequence voltage component and the first negative sequence voltage component, updating the node impedance matrix according to a line parameter in the current wind farm collection line, constructing a second underdetermined equation set according to the corrected negative sequence voltage component and the updated node impedance matrix, reconstructing a second negative sequence fault current node in the second underdetermined equation set through a compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes. ​​

[0065] After the preliminary fault area is determined according to step S20, secondary fault area determination is performed to narrow down the area where the fault may occur. The adjacent nodes of the first fault node are selected, and the negative sequence voltage components of the adjacent nodes are calculated as the second negative sequence voltage components.

[0066] In some optional embodiments, the calculation expression of the second negative sequence voltage component is:

[0067]

[0068] In the formula, Vj represents the negative sequence voltage component of the adjacent node j, Vj represents the negative sequence voltage component of the adjacent node j, is the line length of the node and the node ; is the impedance per unit length of the line; is the admittance per unit length of the line.

[0069] It is worth noting that in the secondary fault area determination process of S30, instead of directly using the second negative sequence voltage component to construct the underdetermined equation set, the first negative sequence voltage component determined in S20 is combined to construct the underdetermined equation set based on the determined modified negative sequence voltage (also referred to as the modified voltage transient component), i.e., the second underdetermined equation set.

[0070] The reason for using the modified negative sequence voltage combined with the updated node impedance matrix is that:

[0071] Because not all nodes in the entire system are equipped with measurement and collection devices, the negative sequence voltage of the adjacent node is obtained through the installed measurement and collection devices, and the modified negative sequence node impedance matrix is obtained.

[0072] In this step, the node impedance matrix is updated according to the line parameters collected in the process of executing step S30 in the current wind farm collection line, to ensure the timeliness of the node impedance matrix.

[0073] In some optional embodiments, the second underdetermined equation set is expressed as:

[0074]

[0075] In the formula, M+T is the node number sum of the first negative sequence voltage component and the second negative sequence voltage component, is the modified negative sequence voltage, is the updated node impedance matrix, is the current signal.

[0076] In this step, after the second underdetermined equation set is constructed, the second negative sequence fault current node in the second underdetermined equation set is reconstructed by using the compressed sensing algorithm, and the two nodes with the highest frequency in the second negative sequence fault current node are taken as the second fault nodes.

[0077] Exemplarily, referring to the process in step S20, the second negative sequence fault current node is reconstructed by using the compressed sensing algorithm after the second underdetermined equation set is constructed. Figure 4 The secondary fault location diagram is shown, which is based on the preliminary fault location result in Figure 3 The secondary fault location diagram is shown, which is based on the preliminary fault location result in

[0078] S40, calculating the third negative sequence voltage component in the fault section composed of the second fault nodes, and updating the node impedance matrix again according to the line parameters in the current wind farm collection line, constructing a third underdetermined equation set according to the third negative sequence voltage component and the node impedance matrix updated again, and reconstructing a third negative sequence fault current node in the third underdetermined equation set by using the compressed sensing algorithm, and taking the two nodes with the highest frequency in the third negative sequence fault current node as the target fault nodes.

[0079] After the secondary fault discrimination is performed according to step S40, a third fault area determination is performed to determine the final fault point.

[0080] In some optional embodiments, the step of calculating the third negative sequence voltage component specifically includes:

[0081] S41, setting the total length of the fault section as x, and calculating the fault voltage values at 0.3x and 0.7x in the fault section respectively;

[0082] S42, taking the negative sequence voltage obtained by decomposing the fault voltage value at 0.3x and the negative sequence voltage obtained by decomposing the fault voltage value at 0.7x as the third negative sequence voltage component.

[0083] In some optional embodiments, the third underdetermined equation set is expressed as:

[0084]

[0085] In the formula, x is the number of the third negative sequence voltage components, is the third negative sequence voltage component, is the node impedance matrix updated again, is the current signal.

[0086] Similarly, referring to the process in step S20 or S30, after the third underdetermined equation set is constructed, the third negative sequence fault current node in the third underdetermined equation set is reconstructed by using the compressed sensing algorithm, and two nodes with the highest frequency in the third negative sequence fault current node are taken as the target fault nodes of the final positioning.

[0087] Exemplarily, referring to Figure 5 The third fault positioning schematic diagram is shown, which is based on the secondary fault positioning result in Figure 4 The fault distance judged after the third reconstruction is 1200-1400 m, and in the simulation process, the preset fault position is 1250 m away from node 4, which meets the expectation.

[0088] In the technical scheme provided in the embodiment, the underdetermined equation set is constructed by using the negative sequence voltage component in the three-phase voltage, the node impedance matrix and the current information when the fault occurs, the fault current node in the underdetermined equation set is reconstructed by using the compressed sensing algorithm multiple times, the final fault area is positioned in multiple times, the fault positioning of the complex wind farm collection line is realized under the condition of a small amount of measurement point collection, and too many measurement devices are avoided.

[0089] In addition, as an implementation scheme, referring to Figure 6 The embodiment further provides a wind farm collection line fault positioning device.

[0090] The acquisition module 100 is configured to acquire a plurality of first negative sequence voltage components in three-phase voltage collected when a fault is detected in the wind farm collection line, a plurality of current signals, and a node impedance matrix constructed by using a line parameter in the wind farm collection line;

[0091] The first reconstruction fault positioning module 200 is configured to construct a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix and the current signal, reconstruct a negative sequence fault current node in the first underdetermined equation set by using the compressed sensing algorithm, take two nodes with the highest frequency in the negative sequence fault current node as a first fault node, calculate a negative sequence voltage component of a neighboring node of the first fault node as a second negative sequence voltage component;

[0092] The secondary reconstruction fault location module 300 is configured to determine a corrected negative sequence voltage component according to the second negative sequence voltage component and the negative sequence voltage component, update the node impedance matrix according to current line parameters in the wind farm collection line, construct a second underdetermined equation set according to the corrected negative sequence voltage component and the updated node impedance matrix, reconstruct a second negative sequence fault current node in the second underdetermined equation set by using a compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes.

[0093] The tertiary reconstruction fault location module 400 is configured to calculate a third negative sequence voltage component in a fault section formed by the second fault nodes, update the node impedance matrix again according to current line parameters in the wind farm collection line, construct a third underdetermined equation set according to the third negative sequence voltage component and the updated node impedance matrix, reconstruct a third negative sequence fault current node in the third underdetermined equation set by using a compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the third negative sequence fault current node as target fault nodes.

[0094] As an implementation scheme, Figure 7 The embodiment of the present application relates to the architecture of the hardware running environment of the computer system.

[0095] As Figure 7 shown, the computer system can include a processor 1001, such as a CPU, a memory 1005, a user interface 1003, a network interface 1004, and a communication bus 1002. The communication bus 1002 is configured to realize the connection and communication among the components. The user interface 1003 can include a display screen (Display) and an input unit, such as a keyboard (Keyboard). The user interface 1003 can also include a standard wired interface and a wireless interface. The network interface 1004 can optionally include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 1005 can be a high-speed RAM memory or a stable memory (non-volatile memory), such as a magnetic disk memory. The memory 1005 can also be a storage device independent of the aforementioned processor 1001.

[0096] Those skilled in the art can understand that Figure 7 the computer system architecture shown in the foregoing embodiments does not constitute a limitation on the computer system, and can include more or fewer components than those shown in the figure, or combine certain components, or arrange different components.

[0097] As Figure 7As shown, the memory 1005 as a storage medium can include an operating system, a network communication module, a user interface module, and a computer program. Among them, the operating system is a program that manages and controls the hardware and software resources of the computer system, and the running of the computer program and other software or programs.

[0098] In Figure 7 In the computer system shown, the user interface 1003 is mainly used to connect the terminal and communicate data with the terminal; the network interface 1004 is mainly used to communicate data with the background server; and the processor 1001 can be used to call the computer program stored in the memory 1005.

[0099] In this embodiment, the computer system comprises a memory 1005, a processor 1001, and a computer program stored in the memory and executable on the processor, wherein:

[0100] When the processor 1001 calls the computer program stored in the memory 1005, the following operations are performed:

[0101] S10, obtaining a plurality of first negative sequence voltage components in the three-phase voltage collected when a fault is detected in the power collection line of the wind farm, a plurality of current signals collected, and a node impedance matrix constructed by the line parameters in the wind farm power collection line at present;

[0102] S20, constructing a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix and the current signal, reconstructing a negative sequence fault current node in the first underdetermined equation set through a compressed sensing algorithm, and taking two nodes with the highest frequency in the negative sequence fault current node as first fault nodes;

[0103] S30, calculating the negative sequence voltage component of the adjacent node of the first fault node as a second negative sequence voltage component, determining a corrected negative sequence voltage component according to the second negative sequence voltage component and the first negative sequence voltage component, updating the node impedance matrix according to the line parameters in the wind farm power collection line at present, constructing a second underdetermined equation set according to the corrected negative sequence voltage component, the updated node impedance matrix and the current signal, reconstructing a second negative sequence fault current node in the second underdetermined equation set through a compressed sensing algorithm, and taking two nodes with the highest frequency in the second negative sequence fault current node as second fault nodes;

[0104] S40, a third negative sequence voltage component in the fault section formed by the second fault node is calculated, and a node impedance matrix is updated again according to a current line parameter in the wind farm collection line, a third underdetermined equation set is constructed according to the third negative sequence voltage component, the node impedance matrix updated again and the current signal, a third negative sequence fault current node in the third underdetermined equation set is reconstructed by a compressed sensing algorithm, and two nodes with the highest occurrence frequency in the third negative sequence fault current node are taken as target fault nodes.

[0105] When the processor 1001 invokes the computer program stored in the memory 1005, the following operations are performed:

[0106] The calculation expression of the second negative sequence voltage component is:

[0107]

[0108] In the formula, Vj represents the negative sequence voltage component of the adjacent node j Vj represents the negative sequence voltage component of the adjacent node j is the line length of the node and the node . is the impedance per unit length of the line; is the admittance per unit length of the line.

[0109] When the processor 1001 invokes the computer program stored in the memory 1005, the following operations are performed:

[0110] The total length of the fault section is set as x, and the fault voltage values at 0.3x and 0.7x in the fault section are calculated respectively;

[0111] The negative sequence voltage obtained by decomposing the fault voltage value at 0.3x and the negative sequence voltage obtained by decomposing the fault voltage value at 0.7x are taken as the third negative sequence voltage component.

[0112] In addition, those skilled in the art can understand that all or part of the processes in the method for implementing the above-mentioned embodiments can be completed by instructing the relevant hardware by a computer program. The computer program includes program instructions, and the computer program can be stored in a storage medium, which is a computer readable storage medium. The program instructions are executed by at least one processor in a computer system to implement the process steps of the above-mentioned embodiment of the method.

[0113] Therefore, the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement each step of the wind farm collection line fault positioning method based on compressed sensing multi-reconstruction as described in the above-mentioned embodiments.

[0114] The computer readable storage medium can be a U disk, a mobile hard disk, a Read-Only Memory (ROM), a magnetic disk or an optical disk, or various computer readable storage media that can store program codes.

[0115] It should be noted that the storage medium provided by the embodiments of the present application is a storage medium used for implementing the method of the embodiments of the present application, and therefore the specific structure and variations of the storage medium can be understood by those skilled in the art based on the method introduced in the embodiments of the present application, and therefore will not be described here. Any storage medium used by the method of the embodiments of the present application belongs to the scope of protection of the present application.

[0116] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0117] The present application is described with reference to flowcharts and / or block diagrams according to the method, device (system) and computer program product of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more blocks or a plurality of blocks.

[0118] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing devices to work in a specific way, so that the instructions stored in the computer readable storage medium produce a manufactured product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more blocks or a plurality of blocks.

[0119] These computer program instructions can also be loaded into a computer or other programmable data processing devices, so that a series of operational steps are generated to realize the computer-implemented processes in the computer or other programmable devices, and the instructions executed in the computer or other programmable devices provide steps for implementing the functions specified in the flowchart Figure 1 or multiple flows and / or blocks Figure 1 Figure 1 or multiple blocks in the flowchart or multiple blocks in the flowchart.

Claims

1. A wind farm collection line fault location method based on compressed sensing multi-reconstruction, characterized in that, The method comprises the following steps: S10, acquiring a plurality of first negative sequence voltage components in three-phase voltage collected when a fault is detected in a power collection line of a wind farm, a plurality of current signals collected, and a node impedance matrix constructed by line parameters in the power collection line of the wind farm at present; S20, constructing a first underdetermined equation set according to the first negative sequence voltage components, the node impedance matrix, and the current signals, reconstructing a negative sequence fault current node in the first underdetermined equation set by a compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the negative sequence fault current node as first fault nodes; S30, calculating a negative sequence voltage component of a neighboring node of the first fault node as a second negative sequence voltage component, determining a corrected negative sequence voltage component according to the second negative sequence voltage component and the first negative sequence voltage component, updating the node impedance matrix according to line parameters in the power collection line of the wind farm at present, constructing a second underdetermined equation set according to the corrected negative sequence voltage component, the updated node impedance matrix, and the current signals, reconstructing a second negative sequence fault current node in the second underdetermined equation set by the compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes; S40, calculating a third negative sequence voltage component in a fault section formed by the second fault nodes, and updating the node impedance matrix again according to line parameters in the power collection line of the wind farm at present, constructing a third underdetermined equation set according to the third negative sequence voltage component, the node impedance matrix updated again, and the current signals, reconstructing a third negative sequence fault current node in the third underdetermined equation set by the compressed sensing algorithm, and taking two nodes with the highest occurrence frequency in the third negative sequence fault current node as target fault nodes; An expression of the first underdetermined equation set is: ； In the formula, M is the node number of the first negative sequence voltage component, is the first negative sequence voltage component, is the node impedance matrix, is the current signal; An expression of the second underdetermined equation set is: ； where M+T is the sum of the first negative sequence voltage component and the second negative sequence voltage component, is the corrected negative sequence voltage quantity, is the updated node impedance matrix, is the current signal; An expression of the third underdetermined equation set is: ； where x is the number of third negative sequence voltage components, is the third negative sequence voltage component, is the updated node impedance matrix, is the current signal.

2. The method of claim 1, wherein, In the S30, an expression for calculating the second negative sequence voltage component is: ； wherein Vnegjdenotes the negative sequence voltage component of the adjacent node j, is the line length between node and node ; is the impedance per unit length of the line; is the admittance per unit length of the line.

3. The method of claim 1, wherein, In the S40, the step of calculating the third negative sequence voltage component in the fault section formed by the second fault nodes comprises the following steps: Setting a total length of the fault section as x, calculating a fault voltage value at 0.3x and a fault voltage value at 0.7x in the fault section respectively; Taking a negative sequence voltage obtained by decomposing the fault voltage value at 0.3x and a negative sequence voltage obtained by decomposing the fault voltage value at 0.7x as the third negative sequence voltage component.

4. The device for realizing fault location of the wind farm power collection line fault location method based on compressed sensing multi-reconstruction according to claim 1, characterized in that, The device comprises: An acquisition module, configured to acquire a plurality of first negative sequence voltage components in three-phase voltage collected when a fault is detected in a power collection line of a wind farm, a plurality of current signals collected, and a node impedance matrix constructed by line parameters in the power collection line of the wind farm at present; The first fault location module is configured to construct a first underdetermined equation set according to the first negative sequence voltage component, the node impedance matrix and the current signal, reconstruct a negative sequence fault current node in the first underdetermined equation set by a compressed sensing algorithm, take two nodes with the highest occurrence frequency in the negative sequence fault current node as first fault nodes, and calculate a negative sequence voltage component of a neighboring node of the first fault node as a second negative sequence voltage component; The second fault location module is configured to determine a corrected negative sequence voltage component according to the second negative sequence voltage component and the negative sequence voltage component, update the node impedance matrix according to a line parameter in the current wind farm collection line, construct a second underdetermined equation set according to the corrected negative sequence voltage component and the updated node impedance matrix, reconstruct a second negative sequence fault current node in the second underdetermined equation set by the compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the second negative sequence fault current node as second fault nodes; The third fault location module is configured to calculate a third negative sequence voltage component in a fault section formed by the second fault nodes, update the node impedance matrix again according to a line parameter in the current wind farm collection line, construct a third underdetermined equation set according to the third negative sequence voltage component and the node impedance matrix updated again, reconstruct a third negative sequence fault current node in the third underdetermined equation set by the compressed sensing algorithm, and take two nodes with the highest occurrence frequency in the third negative sequence fault current node as target fault nodes.

5. A computer system, characterized by The computer system comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the computer program, when executed by the processor, implements the steps of the wind farm collection line fault location method based on compressed sensing multi-reconstruction according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program, when executed by the processor, implements the steps of the wind farm collection line fault location method based on compressed sensing multi-reconstruction according to any one of claims 1 to 3.

Images