Fault positioning method and device for power distribution network containing distributed power supply, terminal equipment and storage medium

Abstract

The invention discloses a fault positioning method and device for a power distribution network containing a distributed power supply, terminal equipment and a storage medium. According to a target current matrix and a target voltage matrix of a current target node, a line impedance matrix of lines between the nodes and a line admittance matrix, the fault positioning of the power distribution network containing the distributed power supply is realized; calculating a node current matrix and a node voltage matrix of a distributed power supply in adjacent nodes, then constructing a fault simulation model, and calculating a fault voltage matrix of a virtual fault position by assuming that a fault occurs between a target node and the adjacent nodes; and then comparing the fault distance between the virtual fault position corresponding to the fault voltage matrix and the target node with the length of the target line, and determining whether the fault position of the power distribution network is on the current target line. Therefore, the method fully considers the influence of the distributed power supply on the voltage and current of the line, and achieves the quick positioning of the fault of the power distribution network through solving the fault simulation model.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method, device, terminal equipment and storage medium for locating faults in a distribution network containing distributed power sources. Background Art

[0002] Faults or short circuits in distribution networks are considered the main cause of power supply interruptions to system users and are responsible for power quality disturbances. One of the effective ways to improve these indicators is to develop and apply short circuit location algorithms. Because the faster and more accurately they are located, the power system can be rebuilt quickly, thus reducing the duration of supply interruptions and the damage caused.

[0003] Traditional distribution network fault location algorithms are usually based on fault impedance. By comparing the changes in current and voltage data before and after the fault, or using the information of circuit breaker tripping and relay operation, combined with the system topology and parameters, the impedance measurement technology is used to locate the fault location. This method is effective in many cases, but it may be inaccurate or slow to respond to complex or multi-fault scenarios. At the same time, when there are distributed power sources in the distribution network, the impedance algorithm may find it difficult to accurately analyze the relationship between voltage and current, thus affecting the reliability of fault location. Summary of the invention

[0004] The embodiments of the present invention provide a method, apparatus, terminal device and storage medium for locating faults in a distribution network containing distributed power sources, which fully consider the influence of distributed power sources on line voltage and current, and realize rapid location of distribution network faults by solving a fault simulation model.

[0005] An embodiment of the present invention provides a method for locating a fault in a distribution network including a distributed power source, comprising:

[0006] Acquire the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources;

[0007] Repeating the fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until the fault location of the distribution network is determined;

[0008] The fault location operation includes:

[0009] Acquire a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node;

[0010] Determine, according to the topological structure, adjacent nodes adjacent to the target node, and determine a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes;

[0011] Calculate a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix;

[0012] A fault simulation model of the target line is constructed according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position;

[0013] Solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node;

[0014] When it is determined that the target fault distance is greater than the length of the target line, the adjacent nodes, the node current matrix, and the node voltage matrix are used as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0015] When it is determined that the target fault distance is not greater than the target line length, the virtual fault position is used as the fault position of the distribution network.

[0016] Furthermore, the fault simulation model is:

[0017]

[0018] Among them, V F abc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V′ LG abc k is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I′ abc k is the target current matrix, β is the second weight of the node current matrix, I abc GD i is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

[0019] Further, solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes:

[0020] Taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value;

[0021] According to the objective function, a preset meta-heuristic algorithm is used to continuously optimize the fault distance and fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm;

[0022] The fault resistance and the fault distance optimized for the last time are determined as the target fault distance and the target fault resistance.

[0023] Further, after constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes:

[0024] According to a preset interval, a number of fault points to be evaluated are obtained from the target line;

[0025] According to the fault simulation model, a voltage matrix to be evaluated is calculated for each fault point to be evaluated under a number of preset fault resistances;

[0026] The largest three-phase voltage value in the plurality of voltage matrices to be evaluated is taken as a value to be evaluated, and added to a preset collection to be evaluated;

[0027] Determining whether the adjacent node is the last node in the distribution network;

[0028] If not, taking the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0029] If yes, then compare the several values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix;

[0030] The fault point to be evaluated corresponding to the target voltage matrix is ​​used as the fault location of the distribution network.

[0031] Another embodiment of the present invention provides a distribution network fault location device including a distributed power source, comprising:

[0032] A data acquisition module, used to acquire the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources;

[0033] A fault location module, configured to repeatedly perform a fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until a fault location of the distribution network is determined;

[0034] The fault location operation includes:

[0035] Acquire a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node;

[0036] Determine, according to the topological structure, adjacent nodes adjacent to the target node, and determine a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes;

[0037] Calculate a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix;

[0038] A fault simulation model of the target line is constructed according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position;

[0039] Solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node;

[0040] When it is determined that the target fault distance is greater than the length of the target line, the adjacent nodes, the node current matrix, and the node voltage matrix are used as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0041] When it is determined that the target fault distance is not greater than the target line length, the virtual fault position is used as the fault position of the distribution network.

[0042] Furthermore, the fault simulation model is:

[0043]

[0044] Among them, V F abc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V′ LG abc k is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I′abc k is the target current matrix, β is the second weight of the node current matrix, I abc GD i is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

[0045] Further, solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes:

[0046] Taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value;

[0047] According to the objective function, a preset meta-heuristic algorithm is used to continuously optimize the fault distance and fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm;

[0048] The fault resistance and the fault distance optimized for the last time are determined as the target fault distance and the target fault resistance.

[0049] Further, after constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes:

[0050] According to a preset interval, a number of fault points to be evaluated are obtained from the target line;

[0051] According to the fault simulation model, a voltage matrix to be evaluated is calculated for each fault point to be evaluated under a number of preset fault resistances;

[0052] The largest three-phase voltage value in the plurality of voltage matrices to be evaluated is taken as a value to be evaluated, and added to a preset collection to be evaluated;

[0053] Determining whether the adjacent node is the last node in the distribution network;

[0054] If not, taking the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0055] If yes, then compare the several values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix;

[0056] The fault point to be evaluated corresponding to the target voltage matrix is ​​used as the fault location of the distribution network.

[0057] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a method for locating faults in a distribution network containing distributed power sources as described in any one of the embodiments is implemented.

[0058] Another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute a distribution network fault location method containing distributed power sources as described in any one of the above embodiments.

[0059] The following beneficial effects are achieved by implementing the present invention:

[0060] The present invention discloses a method, device, terminal equipment and storage medium for locating faults in a distribution network containing distributed power sources. The method traverses the line between two adjacent nodes in the distribution network from one side of a substation, and calculates the node current matrix and the node voltage matrix of the distributed power source in the adjacent node according to the target current matrix, the target voltage matrix, the line impedance matrix of the line between each node, and the line admittance matrix of the current target node, so that when the subsequent fault location is performed, the influence of the distributed power source on the line voltage and current can be fully considered, and then a fault simulation model is constructed, and the fault voltage matrix of the virtual fault position is calculated by assuming that a fault occurs between the target node and the adjacent node, and then the virtual fault position corresponding to the fault voltage matrix is ​​compared with the fault distance of the target node and the length of the target line to confirm whether the fault position of the distribution network is on the current target line. Therefore, the present invention constructs a fault simulation model according to the node current matrix and the node voltage matrix of the distributed power source, fully considers the influence of the distributed power source on the line voltage and current, and realizes the rapid location of the distribution network fault by solving the fault simulation model. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a flow chart of a method for locating faults in a distribution network containing distributed power sources provided by one embodiment of the present invention.

[0062] Figure 2 It is a structural schematic diagram of a distribution network fault locating device including a distributed power source provided by one embodiment of the present invention.

[0063] Figure 3 The topological diagram of the distribution network fault location method provided by one embodiment of the present invention.

[0064] Figure 4 It is another topological diagram of the distribution network fault location method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0067] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0068] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0069] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0070] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0071] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0072] See also Figure 1 , is a flow chart of a method for locating a fault in a distribution network including a distributed power source provided by an embodiment of the present invention, comprising:

[0073] S1. Obtain the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources;

[0074] In a preferred embodiment of the present invention, the starting node is a substation power supply node, which is the main entrance for electric energy to enter the distribution network and has a high voltage level and a large current capacity. The topology structure refers to the connection mode of each node in the distribution network.

[0075] S2, repeating the fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until the fault location of the distribution network is determined;

[0076] The fault location operation includes:

[0077] S21, obtaining a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node;

[0078] S22, determining adjacent nodes adjacent to the target node according to the topological structure, and determining a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes;

[0079] S23, calculating a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix;

[0080] In a preferred embodiment of the present invention, initially, k=1 is set, and the post-fault cyclic window is used in combination with discrete Fourier transform (DFT) to calculate the voltage and current of nodes k, k+1 and distributed power sources in the distribution network after a distribution network fault.

[0081] General electrical model for distribution network lines. Applying Kirchhoff's law at any node m:

[0082] I l abc =I abc m +1 / 2Y abc n-m *V LG abc ;

[0083]

[0084] Where: I l abc is the line current matrix of the three-phase circuit; I abc m is the current matrix of node m; V LG abc is the voltage matrix of node m; I la ,I lb ,I lc are the line currents of phases a, b, and c respectively; V ag 、V bg 、V cg are the line voltages of phases a, b, and c respectively; abc is the admittance matrix of the three-phase circuit. a, b, c, d are the coefficients for calculating the current and voltage of node m from the current and voltage of node n, which can be calculated by the following formula:

[0085] a=U+1 / 2Z abc n-m Y abc n-m

[0086] b=Z abc n-m

[0087] c=Y abc n-m +1 / 4Y abc n-m Z abc n-m Y abc n-m

[0088] d=U+1 / 2Z abc n-m Y abc n-m

[0089] In the formula, Z abc n-m is the impedance matrix of nodes m and n; Y abc n-m is the admittance matrix of nodes m and n; U is the voltage matrix.

[0090] Kirchhoff's law will be applied to a section of bus (target line) between node k (target node) and node k+1 (adjacent node) of the distribution network. When k=1, the line will be between node 01 and node 02. The period of the voltage and post-fault current signals from the reference bus and the bus where the distributed generation is installed will be considered.

[0091] In order to obtain the voltage and current phasors of the three-phase signals of the target line, the post-fault cyclic window will be used in combination with the discrete Fourier transform (DFT). This method is also applicable to buses containing distributed generation, see Figure 3 Taking nodes 01 and 02 as examples, in addition to considering the impedance and admittance matrix shunting of the system, this embodiment also considers the three-phase voltage and current signals of the reference node 01 and the three-phase current signals from the distributed generators installed in the system as available information. Figure 3 :

[0092] V″ LG abc 02 =aV′ LG abc 01 -bI′ abc 01 ;

[0093] I″ abc 02 =-cV′ LG abc 01 +dI′ abc 01 ;

[0094] a=U+1 / 2Z abc 01-02 Y abc 01-02 ;

[0095] b=Z abc 01-02 ;

[0096] c=Y abc 01-02 +1 / 4Y abc 01-02 Z abc 01-02 Y abc 01-02 ;

[0097] d=U+1 / 2Z abc 01-02 Y abc 01-02 ;

[0098] Where V″ LG abc 02 , I″ abc 02 They are the voltage and current matrices of node 02 (adjacent node); V′ LG abc 01 , I′ abc 01 are the voltage and current matrices of node 01 (target node); Z abc 01-02 is the impedance matrix of nodes 01 and 02; Y abc 01-02 is the admittance matrix of nodes 01 and 02.

[0099] S24, constructing a fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position;

[0100] Preferably, the fault simulation model is:

[0101]

[0102] Among them, V F abc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V′ LG abc k is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I′ abc k is the target current matrix, β is the second weight of the node current matrix, I abc GD i is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

[0103] In a preferred embodiment of the present invention, the voltage and current calculated in step S23 are used to construct a fault simulation model to calculate the distance D of the fault relative to k and the fault resistance;

[0104] Consider a fault point applied at a distance D from node 01, where the voltage V Fabc will be:

[0105] V F abc =a(D)V′ LG abc 01 -b(D)I′ abc 01 ;

[0106] a(D)=U+1 / 2L 2 Z abc 01-02 Y abc 01-02 ;

[0107] b(D)=Z abc 01-02 (D) = DZ abc 01-02 ;

[0108] Where V F abc Represents the voltage matrix at the fault location.

[0109] Since the above formula is in V F abcThe calculation of does not reflect the influence of the fault resistance well, and even the influence of the distributed generation cannot be well reflected. For each type of fault (phase to ground (PG), phase to phase (PP), phase to ground to ground PPG, three-phase to ground PPP, and three-phase to ground to ground (PPPG), the fault resistance R is classified. The fault type classification is not the focus of this method, so it is assumed in the method of the present invention that such classification has been performed.

[0110] Considering the influence of distributed generation as current source and fault resistance, assuming that the fault occurs between nodes 01 and 02, according to Figure 3 generate Figure 4 , and considering the above analysis of several short-circuit conditions, the following formula is obtained, which can simulate the effect of fault distance and resistance on V F abc Impact:

[0111]

[0112] Where: is the sum of all N current phasors of the generators downstream of the analyzed section. During a fault, a larger or smaller portion of the upstream and downstream currents will pass through the short circuit, depending on the magnitude of the fault resistance. Thus, as the pinv(*) pseudo-inverse operator, α and β are defined as:

[0113] α=(Z(1-D)+Z D )*pinv(Z(1-D)+R+Z D );

[0114] β=(Z(D)+Z U )*pinv(Z(D)+R+Z U );

[0115] In the formula, Z D represents the equivalent impedance upstream of the analyzed section, Z U is the equivalent impedance downstream of the section. D is calculated by multiplying the distance between the substation and the assumed fault location by the average impedance of all three-phase sections of the system, Z U is calculated by multiplying the distance between the assumed fault location and the remainder of the most important three-phase segment downstream of the fault by the average impedance of all three-phase segments in the system.

[0116] α and β will weigh the contribution of the substation and DG in the fault according to the short-circuit resistance. When the short-circuit resistance tends to zero, α and β will tend to 1 (100% of the current from the substation and DG will be taken into account). When the short-circuit resistance tends to infinity, α and β will tend to 0 (0% of the current from the substation and DG will be taken into account). The voltage at the fault point will be considered as:

[0117]

[0118] The addition of α and β in the above equation makes the proposed mathematical model more sensitive to the fault resistance. F abc The calculation of depends on D and R, both of which are initially unknown variables. By observing V F abc The location of the fault can be determined by the changes in D and R.

[0119] Preferably, after constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes:

[0120] S241. Acquire a number of fault points to be evaluated from the target line according to a preset interval;

[0121] S242, calculating a voltage matrix to be evaluated for each fault point to be evaluated under a number of preset fault resistances according to the fault simulation model;

[0122] S243, taking the largest three-phase voltage value in the plurality of voltage matrices to be evaluated as a value to be evaluated, and adding it to a preset collection to be evaluated;

[0123] S244, determining whether the adjacent node is the last node in the distribution network;

[0124] S245: If not, use the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0125] S246, if yes, then compare the multiple values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix;

[0126] S247: Taking the fault point to be evaluated corresponding to the target voltage matrix as the fault location of the distribution network.

[0127] In a preferred embodiment of the present invention, the estimation starts from the target node, and the fault distance D and the fault resistance R are initially set to zero. For each value of D and R, V is calculated. F abc After that, R remains unchanged, and D increases according to the preset interval ΔD, resulting in:

[0128] D = D + ΔD;

[0129] This process will repeat until:

[0130] D≤D sup ;

[0131] When D reaches this limit D sup Then, re-execute the following process:

[0132] R = R + ΔR;

[0133] Until:

[0134] R≤R sup ;

[0135] Save the max(abs(V F abc )). Finally, the minimum max(abs(V F abc )) value to locate the fault.

[0136] S25, solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node;

[0137] Preferably, solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes:

[0138] S251, taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value;

[0139] S252, according to the objective function, using a preset meta-heuristic algorithm to continuously optimize the fault distance and the fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm;

[0140] S253: Determine the fault resistance and the fault distance optimized for the last time as the target fault distance and the target fault resistance.

[0141] S26, when it is determined that the target fault distance is greater than the length of the target line, taking the adjacent nodes, the node current matrix, and the node voltage matrix as the target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0142] S27. When it is determined that the target fault distance is not greater than the length of the target line, use the virtual fault position as the fault position of the distribution network.

[0143] In a preferred embodiment of the present invention, in order to optimize the search efficiency of the fault distance D and the fault resistance R value, a meta-heuristic algorithm is used for calculation. The meta-heuristic algorithm is selected according to the implicit characteristics to adapt it to the desired objective function, thereby improving the efficiency of the algorithm solution. For the selection of the meta-heuristic algorithm to be used, genetic algorithm, particle swarm optimization (PSO) and simulated annealing (SA) are used for testing. The meta-heuristic is used to minimize the value defined as max(abs(V F abc )) objective function. This embodiment tests three different meta-heuristic algorithms to observe the impact of different algorithms in obtaining D and R. The meta-heuristic algorithm is selected according to the implicit characteristics of each method to adapt it to the desired objective function. In the fault distance measurement process, the meta-heuristic optimization algorithm is used to calculate the fault distance (D) and the fault resistance in turn.

[0144] This embodiment provides a method for locating a fault in a distribution network containing a distributed power source, by traversing from the starting node of the distribution network, according to the target current matrix, target voltage matrix, line impedance matrix of the line between each node, and line admittance matrix of the current target node, the node current matrix and node voltage matrix of the distributed power source in the adjacent node are calculated, so that when the subsequent fault location is performed, the influence of the distributed power source on the line voltage and current can be fully considered, and then the fault simulation model is reconstructed, by assuming that a fault occurs between the target node and the adjacent node, the fault voltage matrix of the virtual fault position is calculated, and then the virtual fault position corresponding to the fault voltage matrix is ​​compared with the fault distance of the target node and the length of the target line to confirm whether the fault position of the distribution network is on the current target line. Therefore, the present invention constructs a fault simulation model according to the node current matrix and the node voltage matrix of the distributed power source, fully considers the influence of the distributed power source on the line voltage and current, and realizes the rapid location of the distribution network fault by solving the fault simulation model.

[0145] See also Figure 2 , is a schematic diagram of a structure of a distribution network fault location device including a distributed power source provided by an embodiment of the present invention, comprising:

[0146] A data acquisition module, used to acquire the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources;

[0147] A fault location module, configured to repeatedly perform a fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until a fault location of the distribution network is determined;

[0148] The fault location operation includes:

[0149] Acquire a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node;

[0150] Determine, according to the topological structure, adjacent nodes adjacent to the target node, and determine a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes;

[0151] Calculate a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix;

[0152] A fault simulation model of the target line is constructed according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position;

[0153] Solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node;

[0154] When it is determined that the target fault distance is greater than the length of the target line, the adjacent nodes, the node current matrix, and the node voltage matrix are used as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0155] When it is determined that the target fault distance is not greater than the target line length, the virtual fault position is used as the fault position of the distribution network.

[0156] Furthermore, the fault simulation model is:

[0157]

[0158] Among them, V F abc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V′ LG abc k is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I′ abc k is the target current matrix, β is the second weight of the node current matrix, I abc GD i is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

[0159] Further, solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes:

[0160] Taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value;

[0161] According to the objective function, a preset meta-heuristic algorithm is used to continuously optimize the fault distance and fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm;

[0162] The fault resistance and the fault distance optimized for the last time are determined as the target fault distance and the target fault resistance.

[0163] Further, after constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes:

[0164] According to a preset interval, a number of fault points to be evaluated are obtained from the target line;

[0165] According to the fault simulation model, a voltage matrix to be evaluated is calculated for each fault point to be evaluated under a number of preset fault resistances;

[0166] The largest three-phase voltage value in the plurality of voltage matrices to be evaluated is taken as a value to be evaluated, and added to a preset collection to be evaluated;

[0167] Determining whether the adjacent node is the last node in the distribution network;

[0168] If not, taking the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation;

[0169] If yes, then compare the several values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix;

[0170] The fault point to be evaluated corresponding to the target voltage matrix is ​​used as the fault location of the distribution network.

[0171] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0172] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0173] Another preferred embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a distribution network fault location method containing distributed power sources as described in any one of the above embodiments.

[0174] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0175] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0176] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0177] Another preferred embodiment of the present invention provides a storage medium, the storage medium is a computer-readable storage medium, the computer program is stored in the computer-readable storage medium, and the computer program, when executed by the processor, can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0178] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for locating faults in a distribution network containing distributed power sources, characterized in that: include: Acquire the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources; Repeating the fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until the fault location of the distribution network is determined; The fault location operation includes: Acquire a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node; Determine, according to the topological structure, adjacent nodes adjacent to the target node, and determine a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes; Calculate a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix; A fault simulation model of the target line is constructed according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position; Solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node; When it is determined that the target fault distance is greater than the length of the target line, the adjacent nodes, the node current matrix, and the node voltage matrix are used as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation; When it is determined that the target fault distance is not greater than the target line length, the virtual fault position is used as the fault position of the distribution network.

2. A method for locating a fault in a distribution network containing distributed power sources as claimed in claim 1, characterized in that: The fault simulation model is: Among them, V Fabc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V L ′ Gabck is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I ′ abck is the target current matrix, β is the second weight of the node current matrix, I abcGDi is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

3. A method for locating a fault in a distribution network containing distributed power sources as claimed in claim 2, characterized in that: The solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes: Taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value; According to the objective function, a preset meta-heuristic algorithm is used to continuously optimize the fault distance and fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm; The fault resistance and the fault distance optimized for the last time are determined as the target fault distance and the target fault resistance.

4. A method for locating faults in a distribution network containing distributed power sources as claimed in claim 2, characterized in that: After constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes: According to a preset interval, a number of fault points to be evaluated are obtained from the target line; According to the fault simulation model, a voltage matrix to be evaluated is calculated for each fault point to be evaluated under a number of preset fault resistances; Taking the largest three-phase voltage value in the plurality of voltage matrices to be evaluated as the value to be evaluated, and adding it to the preset collection to be evaluated; Determining whether the adjacent node is the last node in the distribution network; If not, taking the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation; If yes, then compare the several values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix; The fault point to be evaluated corresponding to the target voltage matrix is ​​used as the fault location of the distribution network.

5. A distribution network fault location device containing distributed power sources, characterized in that: include: A data acquisition module, used to acquire the topological structure of the distribution network where the fault occurs, the line impedance matrix of the lines between the nodes, the line admittance matrix of the lines between the nodes, the current matrix of the starting node, and the voltage matrix of the starting node; wherein the other nodes in the distribution network except the starting node are equipped with distributed power sources; A fault location module, configured to repeatedly perform a fault location operation according to the topological structure, the line impedance matrix, the line admittance matrix, the current matrix, and the voltage matrix until a fault location of the distribution network is determined; The fault location operation includes: Acquire a target node, a target current matrix of the target node, and a target voltage matrix; wherein, initially, the target node is the starting node; Determine, according to the topological structure, adjacent nodes adjacent to the target node, and determine a target impedance matrix and a target admittance matrix of a target line between the target node and the adjacent nodes; Calculate a node current matrix of the distributed power source in the adjacent nodes according to the target current matrix, the target voltage matrix, the target impedance matrix, and the target admittance matrix; A fault simulation model of the target line is constructed according to the target current matrix, the target voltage matrix, and the node current matrix; wherein the fault simulation model is used to assume that a virtual fault position is located between the target node and the adjacent node, and calculate the fault voltage matrix of the virtual fault position; Solving the fault simulation model, calculating the fault voltage matrix, and determining the target fault distance between the corresponding virtual fault position and the target node; When it is determined that the target fault distance is greater than the length of the target line, the adjacent nodes, the node current matrix, and the node voltage matrix are used as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation; When it is determined that the target fault distance is not greater than the target line length, the virtual fault position is used as the fault position of the distribution network.

6. A distribution network fault location device containing distributed power sources as claimed in claim 5, characterized in that: The fault simulation model is: Among them, V Fabc is the fault voltage matrix of the virtual fault location, D is the fault distance between the target node and the virtual fault location, a(D) is the first coefficient, V L ′ Gabck is the target voltage matrix, b(D) is the second coefficient, R is the fault resistance of the virtual fault location, α is the first weight of the target current matrix, I ′ abck is the target current matrix, β is the second weight of the node current matrix, I abcGDi is the node current matrix of the i-th distributed power source in the adjacent node, and N is the total number of distributed power sources in the adjacent node.

7. A fault location device for a distribution network containing a distributed power source as claimed in claim 6, characterized in that: The solving the fault simulation model, calculating the fault voltage matrix, and determining the fault distance between the corresponding virtual fault position and the target node includes: Taking the maximum value of the three-phase voltage values ​​in the fault voltage matrix as the target value, and constructing an objective function with the goal of minimizing the target value; According to the objective function, a preset meta-heuristic algorithm is used to continuously optimize the fault distance and fault resistance in the fault simulation model until a minimum target value is generated; wherein the meta-heuristic algorithm includes: a genetic algorithm, a particle swarm optimization algorithm, and a simulated annealing algorithm; The fault resistance and the fault distance optimized for the last time are determined as the target fault distance and the target fault resistance.

8. A distribution network fault location device containing distributed power sources as claimed in claim 7, characterized in that: After constructing the fault simulation model of the target line according to the target current matrix, the target voltage matrix, and the node current matrix, the method further includes: According to a preset interval, a number of fault points to be evaluated are obtained from the target line; According to the fault simulation model, a voltage matrix to be evaluated is calculated for each fault point to be evaluated under a number of preset fault resistances; Taking the largest three-phase voltage value in the plurality of voltage matrices to be evaluated as the value to be evaluated, and adding it to the preset collection to be evaluated; Determining whether the adjacent node is the last node in the distribution network; If not, taking the adjacent nodes, the node current matrix, and the node voltage matrix as target nodes, target current matrix, and target voltage matrix required for the next round of fault location operation; If yes, then compare the several values ​​to be evaluated in the set to be evaluated, and take the voltage matrix to be evaluated corresponding to the smallest value to be evaluated as the target voltage matrix; The fault point to be evaluated corresponding to the target voltage matrix is ​​used as the fault location of the distribution network.

9. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a method for locating faults in a distribution network containing distributed power sources as described in any one of claims 1 to 4 is implemented.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute a distribution network fault location method containing distributed power sources as described in any one of claims 1 to 4.

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