CN113899981A

CN113899981A - Distributed power supply distribution network fault positioning method and system based on matrix algorithm

Info

Publication number: CN113899981A
Application number: CN202111055746.9A
Authority: CN
Inventors: 王磊; 牛林; 徐志恒; 郭丽娟; 张振海; 商玲玲; 马志广; 李宏博; 马梦朝; 吴德军
Original assignee: State Grid Corp of China SGCC; State Grid of China Technology College; Shandong Electric Power College
Current assignee: State Grid Corp of China SGCC; State Grid of China Technology College; Shandong Electric Power College
Priority date: 2021-09-09
Filing date: 2021-09-09
Publication date: 2022-01-07

Abstract

The invention provides a distributed power supply distribution network fault positioning method and system based on a matrix algorithm, which comprises the following steps: acquiring a network topology containing a distributed power distribution network; constructing a relation description matrix and a fault information matrix according to the network topology; multiplying the constructed relation description matrix and the fault information matrix to obtain a fault judgment matrix, and judging a fault area; wherein the fault determination matrix takes into account loss of information and distortion of fault information for the feeder termination unit. The method provides a fault criterion suitable for fault location of the power distribution network with the distributed power supply, improves the problems of difficult information processing, large calculated amount and general reliability of the traditional algorithm, and adopts a matrix algorithm with simple calculation and strong reliability; the simulation from a single fault to multiple faults is realized based on a PSCAD (power system computer aided design) building model, the conditions of information loss and information distortion are fully considered, and the fault location of the power distribution network with high accuracy and high adaptability is realized.

Description

Distributed power supply distribution network fault positioning method and system based on matrix algorithm

Technical Field

The disclosure belongs to the technical field of power distribution network protection of a power system, and particularly relates to a distributed power supply power distribution network fault positioning method and system based on a matrix algorithm.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

An electric power system is mainly composed of a power plant, a transmission grid, a distribution grid, and electric power consumers, and the distribution grid is an electric power grid that receives electric power from the power plant or transmission grid and supplies electric power to the electric power consumers through distribution facilities. As the last ring on the power supply side, the safety and stability of the distribution network are of great importance for the entire power system.

When a line at a certain position of the power distribution network breaks down, whether the fault area can be timely, quickly and accurately positioned, and the power supply of the non-fault area is timely recovered, so that the power supply reliability and the stable operation capability of the whole power system are realized. With the continuous increase of the permeability of new energy power stations in power systems, the structure of a power distribution network gradually evolves into a complex multi-power-supply network for interconnecting power supplies and users, so that the traditional power distribution network fault location method is not more and more suitable for the requirements of the new power systems, and mainly reflects the reduction of accuracy and universality. Therefore, the research on the fault positioning method of the power distribution network containing the distributed power supply has important significance in improving the power supply reliability of the power system and promoting the development of the distributed power grid. The Feeder Terminal Unit (FTU) is widely applied to the existing power distribution network, a fault positioning method based on the FTU is developed, and the traditional fault positioning algorithm needs to be correspondingly improved and optimized aiming at the problems of complex operation, long calculation period and poor positioning accuracy of the traditional power distribution network fault positioning method, and a more reasonable and complete method needs to be realized according to the FTU to realize fault positioning.

Aiming at the current power distribution network, the main fault positioning algorithm can be divided into a direct algorithm and an indirect algorithm, wherein the direct algorithm comprises an overheating arc searching method and a matrix algorithm based on a graph theory, and the indirect algorithm comprises an artificial neural network, a genetic algorithm, an expert system and the like based on artificial intelligence; however, the traditional active power distribution network fault location has the problems of low accuracy and poor adaptability, and a relevant research on power distribution network fault location is urgently needed to improve the reliability of the operation of a power system.

Disclosure of Invention

In order to solve the problems, the invention provides a distributed power distribution network fault positioning method and system based on a matrix algorithm.

According to some embodiments, a first aspect of the present disclosure provides a distributed power distribution network fault location method based on a matrix algorithm, which adopts the following technical scheme:

a distributed power supply distribution network fault positioning method based on a matrix algorithm comprises the following steps:

acquiring a network topology containing a distributed power distribution network;

constructing a relation description matrix and a fault information matrix according to the network topology;

multiplying the constructed relation description matrix and the fault information matrix to obtain a fault judgment matrix, and judging a fault area;

wherein the fault determination matrix takes into account loss of information and distortion of fault information for the feeder termination unit.

As a further technical limitation, before acquiring a network topology including a distributed power distribution network, a feeder terminal unit attribute matrix needs to be acquired, and inverse operation is performed on the feeder terminal unit attribute matrix to obtain the network topology including the distributed power distribution network.

Further, in the process of obtaining the feeder terminal unit attribute matrix, whether the feeder terminal unit is in normal communication is judged, if so, the feeder terminal unit attribute matrix is directly output according to the state data of the feeder terminal unit, otherwise, the feeder terminal unit attribute matrix is reconstructed.

Further, the reconstruction of the feeder terminal unit attribute matrix is to replace and delete a communication fault row element in an original feeder terminal unit attribute matrix of a feeder terminal unit with abnormal communication, so as to generate a new feeder terminal unit attribute matrix.

As a further technical limitation, in the process of obtaining the fault determination matrix, the conditions of communication interruption and incomplete information loss of the feeder terminal units are considered, the abnormal feeder terminal units are removed, the network topology node information containing the distributed power distribution network is updated, the reconstructed relationship description matrix and the reconstructed fault information matrix are obtained, and the fault determination matrix is obtained.

Furthermore, when a power distribution network containing the distributed power supply receives the influence of an external environment in operation, and a part of fault information uploaded by the feeder line terminal unit has fault information distortion, the distorted fault information needs to be corrected to obtain a corrected fault information matrix, and the fault judgment matrix is obtained by combining the relationship description matrix and the corrected fault information matrix.

Further, when fault information distortion exists, information correction is sequentially carried out on each node of the network topology comprising the distributed power distribution network until distortion information disappears.

According to some embodiments, a second aspect of the present disclosure provides a distributed power distribution network fault location system based on a matrix algorithm, which adopts the following technical solutions:

a distributed power supply distribution network fault positioning system based on a matrix algorithm comprises:

the acquisition module is used for acquiring a network topology containing a distributed power distribution network;

the fault positioning module is used for constructing a relation description matrix and a fault information matrix according to the network topology, multiplying the constructed relation description matrix and the fault information matrix to obtain a fault judgment matrix and judging a fault area;

According to some embodiments, a third aspect of the present disclosure provides a computer-readable storage medium, which adopts the following technical solutions:

a computer readable storage medium, on which a program is stored, which program, when being executed by a processor, carries out the steps of the method for fault location of a distributed power distribution network based on a matrix algorithm according to the first aspect of the present disclosure.

According to some embodiments, a fourth aspect of the present disclosure provides an electronic device, which adopts the following technical solutions:

an electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method for locating a fault in a distributed power distribution network based on a matrix algorithm according to the first aspect of the present disclosure.

Compared with the prior art, the beneficial effect of this disclosure is:

the method provides a fault criterion suitable for fault location of the power distribution network with the distributed power supply, improves the problems of difficult information processing, large calculated amount and general reliability of the traditional algorithm, and adopts a matrix algorithm with simple calculation and strong reliability; the simulation from a single fault to multiple faults is realized based on a PSCAD (power system computer aided design) building model, the conditions of information loss and information distortion are fully considered, and the fault location of the power distribution network with high accuracy and high adaptability is realized.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.

Fig. 1 is a flowchart of a distributed power distribution network fault location method based on a matrix algorithm in an embodiment of the present disclosure;

fig. 2 is a network topology diagram including a distributed power distribution network according to an embodiment of the present disclosure;

fig. 3 is a tidal flow diagram of a network topology including a distributed power distribution network in the presence of a fault according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating a distortion of fault information according to an embodiment of the present disclosure;

fig. 5 is a block diagram of a distributed power distribution network fault location system based on a matrix algorithm in the second embodiment of the present disclosure.

The specific implementation mode is as follows:

the present disclosure is further described with reference to the following drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict.

Example one

The first embodiment of the disclosure introduces a distributed power distribution network fault positioning method based on a matrix algorithm.

In this embodiment, automatic switches in the distribution network are used as nodes to be numbered, the specified positive direction is the switch flow direction in normal operation, and the system operation mode is automatically corrected when changed, so that the defect that the positive direction must be assumed for each power supply is avoided, and the active distribution network fault location method based on the matrix algorithm is used as a core, and the specific process is shown in fig. 1:

fig. 1 shows a distributed power distribution network fault location method based on a matrix algorithm, which includes the following steps:

step S01: constructing an FTU attribute matrix;

step S02: constructing a relation description matrix D according to a network topological structure;

step S03: generating a fault information matrix M according to fault information reported by the FTU;

step S04: reconstructing a relation description matrix D and a fault information matrix M according to specific conditions under the condition of information loss;

step S05: when the fault information is distorted, correcting a fault information matrix M;

step S06: generating a fault judgment matrix P by using the relation description matrix D and the fault information matrix M, and judging a fault area;

step S07: and (6) protecting the operation.

In one or more embodiments, the distribution line is segmented according to distribution switches, i.e., automation switches, of the distribution network installation FTU in step S01. If the communication of the FTUs is normal, an n-row and n-column FTU attribute matrix can be constructed according to the state data of each FTU; if the communication of the FTU is abnormal, such as the communication is interfered, the communication is interrupted, and the like, the FTU attribute matrix needs to be reconstructed. That is, if the communication abnormality occurs to the ith FTU, the third element of the ith row of the original FTU attribute matrix is set to 0, and the FTU attribute moment is setThe element in

column

1 and 2 of array F having the same value as the second element in row i and element F_i2With elements f_i1And replacing, and deleting the ith row vector in the FTU attribute matrix, thereby generating a new FTU attribute matrix. Therefore, the network topology containing the distributed power distribution network can be reconstructed according to the inverse process of the new FTU attribute matrix, and the reconstructed network topology containing the distributed power distribution network is obtained and is shown in fig. 2.

In this embodiment, the FTU attribute matrix is an n-row 3-column matrix, where m is the number of nodes, and three columns of elements respectively indicate the area number corresponding to the port 1, the area number corresponding to the port 2, and the FTU communication condition (1 indicates normal communication, and 0 indicates abnormal communication).

As one or more embodiments, in step S02, a relation description matrix D is formed according to the network topology and the flow direction of the power flow, where the relation description matrix D is an n-row n-column matrix, and the rows correspond to the areas and the columns correspond to the switch nodes.

Specifically, in fig. 2, DG1, DG2, and DG3 are distributed power sources, S1, S2, and S3 are system power sources, black boxes are devices in which FTUs are installed, nodes in the power distribution network topology map are numbered in sequence, areas are formed between the nodes, and the areas are also numbered in sequence, so that the description matrix D can be generated according to the topological combination of the nodes and the areas. The relationship description matrix D has rows representing nodes and columns representing regions. If two nodes m and n of a network are directly connected by a power transmission line, an element D in a relation description matrix D can be paired_mnAnd D_nmAnd assigning a value, and taking-1 or 1. And traversing the whole network, and filling the unconnected residual points with 0 in the relationship description matrix. D_mnThe values are specifically as follows:

when the running mode of the system is changed, such as short-circuit fault, load shedding of a generator and the like, the relation description matrix D can be automatically corrected according to the flow direction of the network tide. The direction of the arrows shown in fig. 2 is the direction of the current flow of the system in a certain operation mode. In the relationship description matrix D, the sum of all elements in each column is 0, that is, the sum of the currents injected and discharged from each node is 0, and conforms to Kirchhoff Current Law (KCL), and the number of non-zero elements in each row is the number of branch lines connected to the region.

As one or more embodiments, in step S03, when a fault occurs in a certain area of the distribution network, a fault current flows through the area, as shown in fig. 3, which is a flow direction of a power flow in the distribution line when the area (2) has a fault, and the master station may form a fault information matrix M according to the fault status uploaded by each FTU, where the fault information matrix M is a column vector M_jThe definition of each element thereof is as follows:

wherein, according to the actual operation structure of the distribution network, the FTU sets three modes of 0, 1 and-1. Where 0 represents no fault current at the node, 1 represents a fault current flowing at the node in the same direction as the positive prescribed direction, and-1 represents a fault current flowing at the node in the opposite direction to the positive prescribed direction.

As one or more embodiments, in step S04, the relationship description matrix D is an n-row and n-column matrix, and the failure information matrix M is an n-row and 1-column matrix, and the two matrices are multiplied to obtain a new matrix with n rows and 1 columns, which is the failure determination matrix P. And if the number of the nonzero elements of a certain row of the relationship description matrix D is more than 2, defining the T area as the area corresponding to the row.

The elements in the failure determination matrix P are defined as follows:

in a power distribution network under an actual working condition, most FTUs are installed outdoors, and the outdoor environment possibly interferes with communication of part of FTUs due to complexity and specificity time-varying property of the outdoor environment, so that fault information of part of FTUs cannot be uploaded to a master station, but the rest of FTUs can still work normally, and the fault information can be uploaded to the master station timely and accurately; therefore, FTUs which do not upload fault information due to self reasons can be removed, a new distribution network topological structure is formed on the basis, and a new relation description matrix D and a fault information matrix M are formed according to the new topological structure.

As one or more implementation manners, in step S05, in an actual operation situation, some FTU communications may be interrupted, and failure information may be missing and incomplete, other FTU communications may still upload failure information normally, an FTU that does not upload failure information needs to be rejected, node information is updated, a switch and an area are renumbered according to a power distribution network topology structure from which a corresponding FTU is rejected, a new relationship description matrix D and a failure information matrix M are constructed, and a failure determination matrix P is obtained by multiplying the new relationship description matrix D and the failure information matrix M to perform failure location according to a failure criterion.

In one or more embodiments, in step S06, in the actual operating state of the power distribution network, due to the influence of the external environment, the fault information uploaded by the FTU may be distorted, and corresponding correction is performed on the information distortion, and then fault location can be performed after the correction. As shown in fig. 4, the distortion condition can be specifically divided into 6 cases, and when the original FTU operation mode is 0 distortion to 1 or-1, both cases correspond to [ 6 ] and [ 1 ] in fig. 4, which belong to the false alarm condition; when the original FTU working mode is that the distortion is-1 or 0, the false alarm and the false alarm are respectively reported in a mode of (5) and (3) in a mode of corresponding to the figure 4; when the original FTU operation mode is-1 distortion to 0 or 1, it corresponds to [ 4 ] missing report and [ 2 ] false report in fig. 4.

When the distortion information is identified, information correction is carried out on a certain node, and the process is repeated until n nodes are corrected until the distortion information disappears completely, and then the corrected fault information matrix is combined with the method to carry out fault positioning.

According to the method and the device, the single fault and the multiple fault of the distribution network can be positioned, and for the active distribution network fault positioning, when the fault occurs, the flow direction of the system tide changes. As shown in fig. 3, a three-phase short-circuit fault is set in the area (2), fault current flows through the area (2), a fault information matrix M is obtained through a simulation result, the relationship description matrix D is multiplied by the fault information matrix M to obtain a fault determination matrix P, P2 in the fault determination matrix P is greater than 1, P4, P6 and P8 are all 1, the fault in the area (2) is determined according to the fault criteria, the result is the same as the hypothesis, and fault location is successful.

During double faults, three-phase short-circuit faults are set at positions (2) and (5) as shown in fig. 3, a fault information matrix M is obtained through a simulation result, a relation description matrix D and the fault information matrix M are multiplied to obtain a fault judgment matrix P, P2 and P5 in the fault judgment matrix P are both greater than 1, P4, P6 and P8 are all 1, fault areas are judged to be (2) and (5) according to the criteria, and the positioning is successful as the assumption.

The embodiment provides a fault criterion suitable for fault location of a distribution point network of a distributed power supply, and the fault criterion is solved by adopting a matrix algorithm. The method is improved aiming at the problems of difficult information processing, large calculation amount and general reliability of the traditional algorithm, and the matrix algorithm is simple in calculation and strong in reliability; the method has the advantages that simulation is carried out from single faults and multiple faults through a PSCAD (power system computer aided design) building model, information loss and information distortion conditions are considered, and compared with the situation that the fault positioning accuracy of the algorithm is high and the adaptability is strong; table 1 below compares the matrix algorithm with the conventional algorithm.

TABLE 1 comparison of matrix Algorithm with conventional Algorithm

Example two

The second embodiment of the disclosure introduces a distributed power distribution network fault positioning system based on a matrix algorithm, and adopts the distributed power distribution network fault positioning method based on the matrix algorithm introduced in the first embodiment.

Fig. 5 shows a distributed power distribution network fault location system based on a matrix algorithm, which includes:

The detailed steps are the same as those of the distributed power distribution network fault location method based on the matrix algorithm provided in the first embodiment, and are not described herein again.

EXAMPLE III

The third embodiment of the disclosure provides a computer-readable storage medium.

A computer readable storage medium, on which a program is stored, which when executed by a processor implements the steps in the method for locating a fault in a distributed power distribution network based on a matrix algorithm according to the first embodiment of the present disclosure.

Example four

The fourth embodiment of the disclosure provides an electronic device.

An electronic device includes a memory, a processor, and a program stored on the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method for locating a fault in a distributed power distribution network based on a matrix algorithm according to an embodiment of the present disclosure.

The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A distributed power supply distribution network fault positioning method based on a matrix algorithm is characterized by comprising the following steps:

2. The method for locating the fault of the power distribution network with the distributed power sources based on the matrix algorithm as claimed in claim 1, wherein before the network topology with the distributed power distribution network is obtained, the attribute matrix of the feeder terminal unit is required to be obtained, and the inverse operation is performed on the attribute matrix of the feeder terminal unit to obtain the network topology with the distributed power distribution network.

3. The method for locating the fault of the distributed power distribution network based on the matrix algorithm as claimed in claim 2, wherein in the process of obtaining the attribute matrix of the feeder terminal unit, it is first determined whether the feeder terminal unit is in normal communication, if so, the attribute matrix of the feeder terminal unit is directly output according to the state data of the feeder terminal unit, otherwise, the attribute matrix of the feeder terminal unit is reconstructed.

4. The method for locating the fault of the distributed power distribution network based on the matrix algorithm as claimed in claim 1, wherein the reconstruction of the attribute matrix of the feeder terminal unit is to replace and delete a communication fault row element in an original attribute matrix of the feeder terminal unit with abnormal communication, so as to generate a new attribute matrix of the feeder terminal unit.

5. The method for locating the fault of the distributed power distribution network based on the matrix algorithm as claimed in claim 1, wherein in the process of obtaining the fault determination matrix, the conditions of communication interruption and incomplete information loss of the feeder terminal units are considered, abnormal feeder terminal units are removed, network topology node information containing the distributed power distribution network is updated, a reconstructed relationship description matrix and a reconstructed fault information matrix are obtained, and the fault determination matrix is obtained.

6. The method for locating the faults of the distribution network of the distributed power sources based on the matrix algorithm as claimed in claim 5, wherein the distribution network containing the distributed power sources is affected by the external environment during operation, and when the fault information distortion exists in part of the fault information uploaded by the feeder terminal unit, the distorted fault information needs to be corrected to obtain a corrected fault information matrix, and the fault determination matrix is obtained by combining the relationship description matrix and the corrected fault information matrix.

7. The method for locating the fault of the distributed power distribution network based on the matrix algorithm as claimed in claim 6, wherein when the fault information distortion exists, the information of each node of the network topology comprising the distributed power distribution network is sequentially corrected until the distortion information disappears.

8. A distributed power distribution network fault positioning system based on a matrix algorithm is characterized by comprising the following components:

9. A computer-readable storage medium, on which a program is stored, which program, when being executed by a processor, carries out the steps of the method for fault localization of a distributed power distribution network based on a matrix algorithm according to any one of claims 1 to 7.

10. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the method for fault location of a distributed power distribution network based on matrix algorithm according to any of claims 1-7.