Power distribution network reconstruction loss reduction method based on undirected graph

Abstract

The invention provides a power distribution network reconstruction loss reduction method based on an undirected graph, and relates to the technical field of power distribution networks, and the method comprises the steps: S1, collecting the historical data of a power distribution network, and obtaining the minimum power distribution network operation loss and the voltage unbalance degree of the power distribution network according to the historical data; s2, taking the minimum distribution network operation loss and the voltage unbalance degree as objective functions, and constructing a distribution network reconstruction loss reduction model; s3, enabling the power distribution network containing the distributed power supply to be equivalent to an undirected graph, and solving the power distribution network reconstruction loss reduction model to obtain an optimal solution meeting constraints; s4, obtaining a power distribution network reconstruction loss reduction result according to the optimal solution; according to the method, the minimum distribution network loss and the voltage unbalance degree are taken as objective functions, numerous complex distribution network equipment is considered, related operation constraints are added, the distribution network reconstruction loss reduction model is constructed, the problems of composite power quality disturbance and additional loss caused by three-phase unbalance are solved, and the power distribution network reconstruction loss reduction efficiency is improved. The power transmission efficiency of the transformer and the line is obviously improved; and power distribution network loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network, and in particular to a distribution network reconstruction loss reduction method based on an undirected graph. Background Art

[0002] In my country's low-voltage distribution network system, due to the existence of factors such as the uncontrollable capacity increase of single-phase load users, the access of single-phase high-power loads and the non-simultaneous access of single-phase loads, the three-phase imbalance problem of the low-voltage distribution network has a more prominent impact on ensuring the reliable and economic operation of the system, especially in the rural low-voltage distribution network system. This leads to increased transformer losses, increased line losses in low-voltage distribution lines, and voltage drops on the user side. In severe cases, it may even cause accidents, affecting the safety, reliability and economic operation of the system. Summary of the invention

[0003] The purpose of the present invention is to provide a distribution network reconstruction loss reduction method based on an undirected graph, which can solve the problems of composite power quality disturbance and additional loss caused by three-phase imbalance, significantly improve the power transmission efficiency of transformers and lines, and reduce distribution network losses.

[0004] The technical solution of the present invention is:

[0005] In a first aspect, the present application provides a method for reducing loss in a distribution network reconstruction based on an undirected graph, which comprises the following steps:

[0006] S1. Collect historical data of the distribution network, and obtain the minimum distribution network operation loss and voltage imbalance of the distribution network based on the historical data;

[0007] S2. Taking the minimum distribution network operation loss and voltage imbalance as the objective function, a distribution network reconstruction loss reduction model is constructed;

[0008] S3, the distribution network containing distributed generation is equivalent to an undirected graph, and the distribution network reconstruction loss reduction model is solved to obtain the optimal solution that satisfies the constraints;

[0009] S4. Obtain the loss reduction result of distribution network reconstruction according to the optimal solution.

[0010] Furthermore, in step S2, taking the minimum distribution network operation loss and voltage imbalance as the objective function, the calculation process of constructing the distribution network reconstruction loss reduction model includes:

[0011] The total objective function set is established with the minimum distribution network operation loss and voltage imbalance as the objective function:

[0012]

[0013] Taking the distribution network operation loss as the objective function:

[0014]

[0015] Taking voltage imbalance as the objective function:

[0016]

[0017] Where min P loss is the minimum distribution network operation loss, minVUF index is the minimum voltage imbalance, P LOSS VUF is the sum of active power losses of all lines in the network. index is the voltage unbalance, l is the number of branches in the network; P i,k , Q i,k are the active power and reactive power flowing through the branch, R i,k is the branch resistance, U i,k is the voltage at the head end of the branch, i represents the a, b, and c phases of the three-phase distribution network, VUF j is the real imbalance index on bus j, is the voltage representing the positive and negative sequence of bus j.

[0018] Furthermore, in step S2, the constraints of the above distribution network reconstruction loss reduction model include:

[0019] Node voltage constraints:

[0020] U jmin <U j,φ <U jmax

[0021] Branch current constraints:

[0022] I imin <I i,φ <I imax

[0023] Power Constraints:

[0024]

[0025] Main transformer capacity constraints:

[0026] T i ≤C i

[0027] The system topology is radial constraints:

[0028]

[0029] Where U j，φ is the node voltage, U jmax , U jmin Respectively represent the upper and lower limits of the voltage at node j, Ii，φ is the branch current, I imax ,I imin They represent the upper and lower limits of the current of branch i, P i , Q i is the active and reactive power of node i, U i , U j is the voltage at nodes i and j, G ii , B ii is the conductance and susceptance of branch ii, G ij , B ij is the conductance and susceptance of branch ij, δ ij is the voltage phase difference of branch ij, C(i) is the set of all nodes connected to node i, P DG,i , Q DG,i is the DG output of node i, P DG，i To contribute to merit, is the maximum and minimum value of active output, Q DG，i For no effort, is the maximum and minimum value of reactive power output, T i is the load of the main variable vertex i, C i To represent the capacity of the main transformer i, β ij , β ji Both represent the parent-child relationship variables of nodes in the spanning tree, N(i) represents the set of nodes connected to node i, α ij It is the state of the switch of branch ij after the distribution network is reconfigured.

[0030] Furthermore, in step S3, the calculation process of solving the distribution network reconstruction loss reduction model to obtain the optimal solution that satisfies the constraints includes:

[0031] The distribution network containing distributed generation is equivalent to an undirected graph:

[0032] G=(V,E,W)

[0033] The optimal solution is equivalent to the minimum spanning tree that satisfies the objective function:

[0034]

[0035] Calculate the voltage balance index to adjust the positions of the tie switch and section switch to obtain the optimal solution that meets the constraints:

[0036]

[0037] Where G represents an undirected graph, V represents a node, E represents a branch, W represents a branch, T represents a minimum spanning tree, W(l) represents the weight of an edge, VBI represents the voltage balance index of each tie switch and section switch in the distribution network, max(UN i ,UNj ) means taking the larger value, min(UN i ,UN j ) means taking a smaller value.

[0038] In a second aspect, the present application provides an electronic device, including:

[0039] A memory for storing one or more programs;

[0040] processor;

[0041] When the one or more programs are executed by the processor, a method for loss reduction in distribution network reconstruction based on an undirected graph as described in any one of the first aspects is implemented.

[0042] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a distribution network reconstruction and loss reduction method based on an undirected graph as described in any one of the first aspects above.

[0043] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0044] (1) The present invention provides a distribution network reconstruction and loss reduction method based on an undirected graph, which adjusts the topological structure of the power system and the access of distributed energy resources through switches, thereby improving the efficiency of the power system, reducing the system cost, and promoting the transformation of the power system towards a clean and efficient direction;

[0045] (2) The present invention takes the minimum distribution network loss and voltage imbalance as the objective function, considers many complex distribution network equipment, adds relevant operation constraints, and constructs a distribution network reconstruction loss reduction model, which significantly improves the power transmission efficiency of transformers and lines, reduces distribution network losses, effectively improves voltage quality, and promotes reliable and stable operation of the distribution network;

[0046] (3) The present invention adjusts the positions of the tie switch and the section switch through the voltage balance index, thereby obtaining an optimal network that satisfies the constraints. It correctly and efficiently realizes the multi-objective optimization of the distribution network with distributed power generation access, further reduces the distribution network loss, and has certain reference significance for the actual distribution network reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0048] Figure 1This is a step diagram of a method for reducing loss in a distribution network reconstruction based on an undirected graph according to Embodiment 1 of the present invention;

[0049] Figure 2 A schematic diagram of a minimum spanning tree according to Embodiment 1 of the present invention;

[0050] Figure 3 This is a schematic diagram of depth traversal of Embodiment 1 of the present invention;

[0051] Figure 4 The improved three-phase IEEE33 node model of embodiment 2 of the present invention;

[0052] Figure 5 This is a comparison diagram of the C phase voltage amplitude in Example 2 of the present invention;

[0053] Figure 6 This is a diagram showing network loss and VUF changes in Example 2 of the present invention;

[0054] Figure 7 This is a schematic structural block diagram of an electronic device according to Embodiment 3 of the present invention.

[0055] Icon: 101, memory; 102, processor; 103, communication interface. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0058] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0059] It should be noted that, in this article, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0060] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0061] Example 1

[0062] See also Figure 1 , Figure 1 The figure shows a step diagram of a distribution network reconstruction loss reduction method based on an undirected graph provided in an embodiment of the present application.

[0063] In a first aspect, the present application provides a method for reducing loss in a distribution network reconstruction based on an undirected graph, which comprises the following steps:

[0064] S1. Collect historical data of the distribution network, and obtain the minimum distribution network operation loss and voltage imbalance of the distribution network based on the historical data;

[0065] S2. Taking the minimum distribution network operation loss and voltage imbalance as the objective function, a distribution network reconstruction loss reduction model is constructed;

[0066] S3, the distribution network containing distributed generation is equivalent to an undirected graph, and the distribution network reconstruction loss reduction model is solved to obtain the optimal solution that satisfies the constraints;

[0067] S4. Obtain the loss reduction result of distribution network reconstruction according to the optimal solution.

[0068] As a preferred implementation, in step S2, taking the minimum distribution network operation loss and voltage imbalance as the objective function, the calculation process of constructing the distribution network reconstruction loss reduction model includes:

[0069] The total objective function set is established with the minimum distribution network operation loss and voltage imbalance as the objective function:

[0070]

[0071] Taking the distribution network operation loss as the objective function:

[0072]

[0073] Taking voltage imbalance as the objective function:

[0074]

[0075] Where minP loss is the minimum distribution network operation loss, minVUF index is the minimum voltage imbalance, P LOSS VUF is the sum of active power losses of all lines in the network. index is the voltage unbalance, l is the number of branches in the network; P i,k , Q i,k are the active power and reactive power flowing through the branch, R i,k is the branch resistance, U i,k is the voltage at the head end of the branch, i represents the a, b, and c phases of the three-phase distribution network, VUF j is the real imbalance index on bus j, is the voltage representing the positive and negative sequence of bus j.

[0076] As a preferred implementation, in step S2, the constraints of the distribution network reconstruction loss reduction model include:

[0077] Node voltage constraints:

[0078] U jmin <U j,φ <U jmax

[0079] Branch current constraints:

[0080] I imin <I i,φ <I imax

[0081] Power Constraints:

[0082]

[0083] Main transformer capacity constraints:

[0084] T i ≤C i

[0085] The system topology is radial constraints:

[0086]

[0087] Where U j，φ is the node voltage, U jmax , U jmin Respectively represent the upper and lower limits of the voltage at node j, I i，φ is the branch current, I imax ,I imin They represent the upper and lower limits of the current of branch i, Pi , Q i is the active and reactive power of node i, U i , U j is the voltage at nodes i and j, G ii , B ii is the conductance and susceptance of branch ii, G ij , B ij is the conductance and susceptance of branch ij, δ ij is the voltage phase difference of branch ij, C(i) is the set of all nodes connected to node i, P DG,i , Q DG,i is the DG output of node i, P DG，i To contribute to merit, is the maximum and minimum value of active output, Q DG，i For no effort, is the maximum and minimum value of reactive power output, T i is the load of the main variable vertex i, C i To represent the capacity of the main transformer i, β ij , β ji Both represent the parent-child relationship variables of nodes in the spanning tree. If node i is the child node of j, then β ij =1, otherwise 0, N(i) represents the set of nodes connected to node i, α ij It is the state of the switch of branch ij after the distribution network is reconfigured.

[0088] As a preferred implementation, in step S3, the calculation process of solving the distribution network reconstruction loss reduction model to obtain the optimal solution that satisfies the constraints includes:

[0089] like Figure 2 As shown in the figure, using the basic graph theory, the radial distribution network can be described as a tree, with the substation outlet of the power system equivalent to the root node, the line switch equivalent to the edge, and the load and distributed power supply equivalent to the point. Then the entire distribution network containing distributed power supply can be equivalent to an undirected graph:

[0090] G=(V,E,W)

[0091] The optimal solution to the distribution network reconstruction problem can be considered as a minimum spanning tree T that satisfies the objective function. W(l) represents the weight of the edge, and the minimum spanning tree of all load nodes and the root node can be expressed as:

[0092]

[0093] It should be noted that this embodiment adopts DFS depth-first search, such as Figure 3As shown, starting from a starting node, visit nodes as far as possible along a path until you reach a node where you can no longer move forward, then return to the previous layer to continue exploring other paths. This process is recursive, by continuously going deeper into the child nodes of the node until the entire graph is traversed.

[0094] Calculate the voltage balance index to adjust the positions of the tie switch and section switch to obtain the optimal solution that meets the constraints:

[0095]

[0096] Where G represents an undirected graph, V represents a node, E represents a branch, W represents a branch, T represents a minimum spanning tree, W(l) represents the weight of an edge, VBI represents the voltage balance index of each tie switch and section switch in the distribution network, max(UN i ,UN j ) means taking the larger value, min(UN i ,UN j ) means taking a smaller value.

[0097] Example 2

[0098] Embodiment 2 of the present invention builds an improved three-phase IEEE33 node simulation model of a single transformer substation and a single feeder on a MATLAB / Simulink platform.

[0099] The improved three-phase IEEE33 node simulation power grid structure used is as follows Figure 4 As shown, the load of phase A remains unchanged at 1200kW+733kVar, the load of phase B increases by 1.5 times to 1800kW+1148kVar, and the load of phase C increases by 2 times to 2460kW+1534kVar.

[0100] Among them, nodes 7, 11, 16, 21, 25, and 30 are connected to a doubly-fed wind turbine, an energy storage battery, a doubly-fed wind turbine, a photovoltaic power station, a photovoltaic power station, and an asynchronous wind turbine generator, respectively. Their specific parameters and connection phases are shown in Table 1.

[0101] Table 1

[0102]

[0103]

[0104] The C phase voltage amplitude change curves before reconstruction and after the proposed method, particle swarm optimization, and second-order cone programming are shown in the figure. Figure 5 As shown, the network loss and unbalance index VUF change as follows Figure 6As shown, it can be seen that the network loss is reduced by 135.589 kW through the method of the present invention, and the loss reduction rate is 24.48%, while the loss reduction rates through the particle swarm algorithm and the second-order cone programming are 18.97% and 14.04% respectively. The specific data are shown in Table 2.

[0105] Table 2

[0106] Methods Particle Swarm Optimization Second-Order Cone Programming Disconnect switch 7,10,13,28,36 7,10,14,28,31 7,9,14,32,37 <![CDATA[Initial P loss / kW]]> 553.953 553.953 553.953 <![CDATA[P loss / kW]]> 418.364 448.854 476.205 Loss reduction rate / % 24.48 18.97 14.04 <![CDATA[Initial VUF index > 1.748 1.748 1.748 <![CDATA[VUF index ]]> 1.144 1.238 1.197 <![CDATA[VUF index Reduction rate / %]]> 34.55 29.17 31.52 Node minimum voltage / pu 0.959(33,C phase) 0.951(32,C phase) 0.959(32,C phase)

[0107] In summary, the present invention adjusts the topological structure of the power system and the access of distributed energy resources by opening and closing switches, thereby improving the efficiency of the power system and reducing the system cost. Compared with the particle swarm algorithm and the second-order cone programming method, the method provided by the present invention is more effective in reducing network losses and voltage imbalance, effectively improving voltage quality, reducing distribution network operation losses, and promoting reliable and stable operation of the distribution network.

[0108] Example 3

[0109] See also Figure 7 , Figure 7 A schematic structural block diagram of an electronic device provided in an embodiment of the present application.

[0110] An electronic device includes a memory 101, a processor 102 and a communication interface 103, wherein the memory 101, the processor 102 and the communication interface 103 are electrically connected to each other directly or indirectly to realize data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The memory 101 can be used to store software programs and modules, and the processor 102 executes various functional applications and data processing by executing the software programs and modules stored in the memory 101. The communication interface 103 can be used to communicate signaling or data with other node devices.

[0111] Among them, the memory 101 can be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc.

[0112] The processor 102 may be an integrated circuit chip with signal processing capability. The processor 102 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0113] It is understood that the structure shown in the figure is only for illustration, and a method for reducing loss by reconfiguring a distribution network based on an undirected graph may also include more or fewer components than those shown in the figure, or have a different configuration than that shown in the figure. Each component shown in the figure may be implemented by hardware, software, or a combination thereof.

[0114] In the embodiments provided in the present application, it should be understood that the disclosed method can also be implemented in other ways. The embodiments described above are merely schematic, for example, the flowchart or block diagram in the accompanying drawings shows the possible implementation architecture, functions and operations of the method and computer program product according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0115] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0116] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0117] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0118] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A distribution network reconstruction loss reduction method based on undirected graph, characterized in that: The following steps are involved: S1. Collect historical data of the distribution network, and obtain the minimum distribution network operation loss and voltage imbalance of the distribution network based on the historical data; S2. Taking the minimum distribution network operation loss and voltage imbalance as the objective function, a distribution network reconstruction loss reduction model is constructed; S3, the distribution network containing distributed generation is equivalent to an undirected graph, and the distribution network reconstruction loss reduction model is solved to obtain the optimal solution that satisfies the constraints; S4. Obtain the loss reduction result of distribution network reconstruction according to the optimal solution.

2. A method for reducing loss in distribution network reconstruction based on an undirected graph as claimed in claim 1, characterized in that: In step S2, taking the minimum distribution network operation loss and voltage imbalance as the objective function, the calculation process of constructing the distribution network reconstruction loss reduction model includes: The total objective function set is established with the minimum distribution network operation loss and voltage imbalance as the objective function: Taking the distribution network operation loss as the objective function: Taking voltage imbalance as the objective function: Where min P loss is the minimum distribution network operation loss, minVUF index is the minimum voltage imbalance, P LOSS VUF is the sum of active power losses of all lines in the network. index is the voltage unbalance, l is the number of branches in the network; P i,k , Q i,k are the active power and reactive power flowing through the branch, R i,k is the branch resistance, U i,k is the voltage at the head end of the branch, i represents the a, b, and c phases of the three-phase distribution network, VUF j is the real imbalance index on bus j, is the voltage representing the positive and negative sequence of bus j.

3. A method for reducing loss by reconfiguring a distribution network based on an undirected graph as claimed in claim 2, characterized in that: In step S2, the constraints of the distribution network reconstruction loss reduction model include: Node voltage constraints: IN jmin <In j,φ <In jmax Branch current constraints: I imin <I i,φ <I imax Power Constraints: Main transformer capacity constraints: T i ≤C i The system topology is radial constraints: Where U j，φ is the node voltage, U jmax , U jmin Respectively represent the upper and lower limits of the voltage at node j, I i，φ is the branch current, I imax ,I imin They represent the upper and lower limits of the current of branch i, P i , Q i is the active and reactive power of node i, U i , U j is the voltage at nodes i and j, G ii , B ii is the conductance and susceptance of branch ii, G ij , B ij is the conductance and susceptance of branch ij, δ ij is the voltage phase difference of branch ij, C(i) is the set of all nodes connected to node i, P DG,i , Q DG,i is the DG output of node i, P DG，i To contribute to merit, is the maximum and minimum value of active output, Q DG，i For no effort, is the maximum and minimum value of reactive power output, T i is the load of the main variable vertex i, C i To represent the capacity of the main transformer i, β ij , β ji Both represent the parent-child relationship variables of nodes in the spanning tree, N(i) represents the set of nodes connected to node i, α ij It is the state of the switch of branch ij after the distribution network is reconfigured.

4. A method for reducing loss by reconfiguring a distribution network based on an undirected graph as claimed in claim 1, characterized in that: In step S3, the calculation process of solving the distribution network reconstruction loss reduction model to obtain the optimal solution that meets the constraints includes: The distribution network containing distributed generation is equivalent to an undirected graph: G=(V,E,W) The optimal solution is equivalent to the minimum spanning tree that satisfies the objective function: Calculate the voltage balance index to adjust the positions of the tie switch and section switch to obtain the optimal solution that meets the constraints: Where G represents an undirected graph, V represents a node, E represents a branch, W represents a branch, T represents a minimum spanning tree, W(l) represents the weight of an edge, VBI represents the voltage balance index of each tie switch and section switch in the distribution network, max(UN i ,UN j ) means taking the larger value, min(UN i ,UN j ) means taking a smaller value.

5. An electronic device, characterized in that: include: A memory for storing one or more programs; processor; When the one or more programs are executed by the processor, a distribution network reconstruction loss reduction method based on an undirected graph as described in any one of claims 1 to 4 is implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for reducing loss in distribution network reconstruction based on an undirected graph as described in any one of claims 1 to 4 is implemented.

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