A distribution network grid division method and system

Abstract

The present invention discloses a distribution network grid division method and system. According to the peak time and valley time marked in the constructed load matrix and the constructed peak-valley time matrix, the peak-valley difference of each plot at the peak time and valley time is determined to obtain the plot peak-valley difference matrix. Based on the connection matrix, the grids to which each plot belongs are used as variables to be optimized to construct the plot belonging matrix. The plot peak-valley difference matrix is ​​used as input, and the plot belonging matrix is ​​used as the variable to be optimized to establish an integer programming model. The plot belonging matrix in the integer programming model is solved to obtain the target plot belonging matrix. Each plot is divided into a corresponding network according to the target plot belonging matrix to obtain a plot division result. When all grids have only one connected subgraph and the actual peak-valley time of the grid is the same as the corresponding value in the peak-valley time matrix, the plot division result is determined as the final result. The present invention can complete the distribution network grid division without manual intervention, thereby improving the efficiency of distribution network planning.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution network, and more specifically, to a power distribution network grid division method and system. Background Art

[0002] Distribution network grid division is a crucial link in power grid planning. It mainly divides the land in the distribution network area into several grids economically and reasonably based on the load forecast results of power users and the geographical location information of the load. The reasonable division of grids helps the efficient planning of distribution lines and the reasonable site selection of substations. How to scientifically and reasonably realize the grid division of distribution networks has become a hot topic of current research.

[0003] At present, the land parcels are generally judged based on multiple indicators such as land parcel attributes, geographical location and economic level, and the distribution grid is manually drawn. However, since the selection of indicators is highly subjective and the grid needs to be adjusted manually, the entire distribution network grid planning process is complicated. Summary of the invention

[0004] In view of this, the present invention discloses a distribution network grid division method and system to realize automatic division of plots, and distribution network grid division can be completed without human intervention, thereby improving the planning efficiency of the distribution network.

[0005] A distribution network grid division method, comprising:

[0006] Constructing a load matrix according to load forecast information between plots in the distribution network planning area, and constructing a peak-valley time matrix according to the determined number of grids and preset peak-valley time initial values;

[0007] According to the load matrix and the peak and valley times marked in the peak and valley time matrix, the peak-valley difference of each plot at the peak time and the valley time is determined to obtain a plot peak-valley difference matrix;

[0008] Based on the connection matrix, the grid to which each block belongs is used as a variable to be optimized to construct a block belonging matrix, wherein the connection matrix is ​​constructed based on the topological information between the blocks in the distribution network planning area;

[0009] Taking the plot peak-to-valley difference matrix as input and the plot belonging matrix as the variable to be optimized, an integer programming model is established;

[0010] Taking the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization goal, and the number of plots in the grid and the load peak as constraints, solving the plot ownership matrix to obtain the solved target plot ownership matrix;

[0011] Divide each plot into a corresponding network according to the target plot belonging matrix to obtain a plot division result;

[0012] Determine whether all grids in the land parcel division result have only one connected subgraph;

[0013] If yes, determining whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix;

[0014] If yes, the plot division result is determined as the target plot division result of the distribution network grid.

[0015] Optionally, the load matrix is ​​expressed as follows:

[0016]

[0017] Where, E represents the load matrix, e i，j It represents the load power of the ith plot at time j, and N represents the total number of plots in the distribution network planning area.

[0018] Optionally, the peak-valley moment matrix is ​​expressed as follows:

[0019]

[0020] Where, T represents the peak-valley time matrix, t i，peak represents the peak time of the ith grid, t i，valley represents the valley moment of the i-th grid, N set Indicates the total number of grids.

[0021] Optionally, the connection matrix is ​​expressed as follows:

[0022]

[0023] Where V represents the connection matrix, v i，j It represents the connection relationship between the i-th plot and the j-th plot, 1 represents connection, 0 represents no connection, and N represents the total number of plots in the distribution network planning area.

[0024] Optionally, the expression of the plot peak-to-valley difference matrix is ​​as follows:

[0025]

[0026] Where D represents the peak-to-valley difference matrix of the plot, d i，j represents the peak-to-valley difference of the i-th plot in the j-th grid, Indicates that the i-th plot is at t j，peak Load power at time t j，peak represents the peak time of the jth grid, Indicates that the i-th plot is at t j，valley Load power at time tj，valley represents the valley moment of the jth grid;

[0027] The expression of the plot attribution matrix is ​​as follows:

[0028]

[0029] Where B represents the land parcel ownership matrix, b i ∈{1,2,…,N set} represents the grid to which the ith plot belongs, which is the variable to be optimized. set Indicates the total number of grids.

[0030] Optionally, the optimization objective function corresponding to the optimization objective is: Represents the sum of the peak-to-valley differences of each grid, where Set j represents the set of plots belonging to the jth grid;

[0031] The constraints include: lot quantity constraint and grid capacity constraint;

[0032] Among them, the number of plots is constrained as follows: N min ≤N i ≤N max , i∈{1, 2, …, N set},N i represents the number of plots in the i-th grid, N min represents the lower limit of the number of plots in the grid, N max Indicates the upper limit of the number of plots in the grid;

[0033] The grid capacity constraint is: S min represents the lower limit of the peak load in the grid, S max Indicates the upper limit of the peak load in the grid.

[0034] Optionally, the step of determining whether all grids in the land parcel division result have only one connected subgraph includes:

[0035] Performing a union-find test on the plot division results to determine the number of connected subgraphs under each grid;

[0036] Determine whether all grids have only one connected subgraph.

[0037] Optionally, the step of performing a union-find test on the plot division result to determine the number of connected subgraphs under each grid includes:

[0038] Determine whether the current edge traversed at the current moment is an initial edge, wherein the current edge is an edge formed between two interconnected plots in the same grid in the plot division result;

[0039] If the current edge is the initial edge, any one of the two nodes of the current edge is selected as the upper node, and the other node is set as the lower node, and each of the nodes corresponds to a plot in the plot division result;

[0040] If the current edge is not the initial edge, traversing the current edge according to a preset non-initial edge traversal scheme;

[0041] Determine whether the current edge is the last edge traversed;

[0042] If yes, the affiliation of each node in all the traversed edges is sorted out, and the number of connected subgraphs under each grid is obtained by counting, wherein each top-level node corresponds to a connected subgraph.

[0043] Optionally, if the current edge is not the initial edge, the step of traversing the current edge according to a preset non-initial edge traversal scheme includes:

[0044] If the current edge is not the initial edge, determining whether there is a traversed node between two nodes of the current edge;

[0045] If there is no traversed node, one of the two nodes of the current edge is randomly selected as the upper node, and the other node is set as the lower node;

[0046] If there are traversed nodes, determine whether the number of traversed nodes is one or two;

[0047] When there is only one traversed node, the traversed node is set as the parent node, and the untraversed node is set as the child node;

[0048] When there are two traversed nodes, determine whether the top nodes of the two traversed nodes are the same;

[0049] If they are not the same, one of the two top-level nodes is randomly selected as the parent node of the other top-level node;

[0050] If they are the same, it is determined that no additional node relationship needs to be set.

[0051] Optionally, also include:

[0052] When all grids in the land parcel division result do not have only one connected subgraph, extracting the largest connected subgraph under each grid;

[0053] The corresponding variables of all the extracted plots under the maximum connected subgraph in the plot attribution matrix are set as constants, and the variables corresponding to the plots in the plot attribution matrix except the plots under the maximum connected subgraph are set as variables to be optimized, and the integer programming model is re-established by returning to the step.

[0054] Optionally, the step of determining whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix comprises:

[0055] Draw a total load curve of each grid based on the plot division result;

[0056] Based on each of the total load curves, it is determined whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix.

[0057] Optionally, also include:

[0058] When the actual peak and valley moments of the grid are different from the corresponding values ​​in the peak and valley moment matrix, the corresponding values ​​in the peak and valley moment matrix are updated with the actual peak and valley moments, and the peak and valley difference matrix of the plot is returned to be recalculated.

[0059] A distribution network grid division system, comprising:

[0060] A first matrix construction unit is used to construct a load matrix according to load forecast information between plots in a distribution network planning area, and to construct a peak-valley time matrix according to a determined number of grids and preset peak-valley time initial values;

[0061] The second matrix construction unit is used to determine the peak-valley difference of each plot at the peak time and the valley time according to the load matrix and the peak time and valley time marked in the peak-valley time matrix, and obtain a plot peak-valley difference matrix;

[0062] A third matrix construction unit is used to construct a plot belonging matrix by taking the grids to which each plot belongs as variables to be optimized based on a connection matrix, wherein the connection matrix is ​​constructed based on topological information between plots in the distribution network planning area;

[0063] A model building unit, used to take the plot peak-to-valley difference matrix as input and the plot belonging matrix as a variable to be optimized, and to build an integer programming model;

[0064] A matrix solving unit is used to solve the plot ownership matrix by taking the minimum sum of peak-to-valley differences of each grid in the integer programming model as the optimization target and the number of plots in the grid and the load peak as the constraint conditions to obtain the solved target plot ownership matrix;

[0065] A division unit, used to divide each block into a corresponding network according to the target block belonging matrix, and obtain a block division result;

[0066] A first judging unit is used to judge whether all grids in the land parcel division result have only one connected subgraph;

[0067] A second judgment unit is used to judge whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix when the first judgment unit judges that the value is yes;

[0068] A division result determination unit is used to determine the plot division result as the target plot division result of the distribution network grid when the second determination unit determines that the result is yes.

[0069] It can be seen from the above technical solution that the present invention discloses a distribution network grid division method and system, which constructs a load matrix according to the load forecast information between plots in the distribution network planning area, and constructs a peak-valley time matrix according to the determined number of grids and the preset peak-valley time initial values, and determines the peak-valley difference of each plot at the peak time and the valley time according to the peak time and the valley time marked in the load matrix and the peak-valley time matrix to obtain the plot peak-valley difference matrix, and constructs a plot belonging matrix based on the connection matrix, taking the grids to which each plot belongs as the variable to be optimized, and taking the plot peak-valley difference matrix as input, and obtaining the plot belonging matrix. The matrix is ​​used as the variable to be optimized, and an integer programming model is established. The minimum sum of the peak-to-valley differences of each grid in the integer programming model is used as the optimization target, and the number of plots in the grid and the load peak are used as constraints. The plot attribution matrix is ​​solved to obtain the solved target plot attribution matrix, and each plot is divided into the corresponding network according to the target plot attribution matrix to obtain the plot division result. When all grids in the plot division result have only one connected subgraph, and the actual peak-to-valley time of the grid is the same as the corresponding value in the peak-to-valley time matrix, the plot division result is determined as the target plot division result of the distribution network grid. It can be seen from this that the present invention realizes the automatic division of plots, and the distribution network grid division can be completed without manual intervention, thereby improving the efficiency of distribution network planning. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without paying creative work.

[0071] Figure 1 A flow chart of a distribution network grid division method disclosed in an embodiment of the present invention;

[0072] Figure 2A flow chart of a method disclosed in an embodiment of the present invention for performing a union-find test on a plot division result to determine the number of connected subgraphs under each grid;

[0073] Figure 3 A flowchart of a method for traversing a current edge according to a preset non-initial edge traversal scheme when the current edge is not an initial edge disclosed in an embodiment of the present invention;

[0074] Figure 4 A flow chart of another distribution network grid division method disclosed in an embodiment of the present invention;

[0075] Figure 5 A schematic diagram of land plot distribution in a planning area disclosed in an embodiment of the present invention;

[0076] Figure 6 A schematic diagram of a plot division result disclosed in an embodiment of the present invention;

[0077] Figure 7 A schematic diagram of a load curve of a grid 1 disclosed in an embodiment of the present invention;

[0078] Figure 8 A schematic diagram of a load curve of a grid 2 disclosed in an embodiment of the present invention;

[0079] Fig. 9 A schematic diagram of the structure of a distribution network grid division system disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0080] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0081] The embodiment of the present invention discloses a distribution network grid division method and system. A load matrix is ​​constructed according to load forecast information between plots in a distribution network planning area, and a peak-valley time matrix is ​​constructed according to a determined number of grids and a preset peak-valley time initial value. According to the peak time and valley time marked in the load matrix and the peak-valley time matrix, the peak-valley difference of each plot at the peak time and the valley time is determined to obtain a plot peak-valley difference matrix. Based on a connection matrix, the grids to which each plot belongs are used as variables to be optimized to construct a plot belonging matrix. The plot peak-valley difference matrix is ​​used as input, and the plot belonging matrix is ​​used as a variable to be optimized. An integer programming model is established. The sum of the peak-valley differences of each grid in the integer programming model is minimized as an optimization target. The number of plots in the grid and the load peak value are used as constraints. The plot belonging matrix is ​​solved to obtain a solved target plot belonging matrix. Each plot is divided into a corresponding network according to the target plot belonging matrix to obtain a plot division result. When all grids in the plot division result have only one connected subgraph, and the actual peak-valley time of the grid is the same as the corresponding value in the peak-valley time matrix, the plot division result is determined as the target plot division result of the distribution network grid. It can be seen from this that the present invention realizes the automatic division of plots and can complete the distribution network grid division without human intervention, thereby improving the efficiency of distribution network planning.

[0082] In addition, the present invention takes the load curve of the land into consideration, takes the minimum peak-to-valley difference as the goal, realizes grid division, and thus improves the utilization rate of the distribution network equipment.

[0083] See also Figure 1 , a flow chart of a distribution network grid division method disclosed in an embodiment of the present invention, the method comprising:

[0084] Step S101: construct a load matrix according to load forecast information between plots in a distribution network planning area, and construct a peak-valley time matrix according to a determined number of grids and preset peak-valley time initial values.

[0085] Among them, the plot is the basic unit of the grid planning system. Its scope corresponds to the functional plot in the land use planning and control detailed planning, and takes into account the power supply scope of the distribution room or substation.

[0086] A grid refers to a functional unit consisting of several adjacent plots of land with the same or similar power supply area classification levels, power consumption types and basically consistent power supply reliability requirements, according to the city's control detailed planning.

[0087] Among them, load forecast information can be directly obtained from the power grid geographic information system and planning system.

[0088] The number of grids is determined by the distribution network planning objectives and the power grid to be planned.

[0089] The initial value of the peak and valley time is determined according to actual needs, and the present invention does not limit it here.

[0090] In this embodiment, the expression of the load matrix is ​​as follows:

[0091]

[0092] Where, E represents the load matrix, e i，j It represents the load power of the ith plot at time j, and N represents the total number of plots in the distribution network planning area.

[0093] The expression of the peak and valley moment matrix is ​​as follows:

[0094]

[0095] Where, T represents the peak-valley time matrix, t i，peak represents the peak time of the ith grid, t i，valley represents the valley moment of the i-th grid, N set Indicates the total number of grids.

[0096] Step S102: According to the load matrix and the peak and valley times marked in the peak and valley time matrix, determine the peak-valley difference of each plot at the peak time and valley time, and obtain the plot peak-valley difference matrix.

[0097] The peak-to-valley difference refers to the difference between the maximum load and the minimum load of the power system in a day.

[0098] Among them, the expression of the plot peak-to-valley difference matrix is ​​as follows:

[0099]

[0100] Where D represents the peak-to-valley difference matrix of the plot, d i，j represents the peak-to-valley difference of the i-th plot in the j-th grid, Indicates that the i-th plot is at t j，peak Load power at time t j，peak represents the peak time of the jth grid, Indicates that the i-th plot is at t j，valley Load power at time t j，valley represents the valley moment of the j-th grid.

[0101] Step S103: Based on the connection matrix, the grids to which each plot belongs are taken as variables to be optimized to construct a plot belonging matrix.

[0102] The connection matrix is ​​constructed based on the topological information between the plots in the distribution network planning area.

[0103] In this embodiment, the expression of the connection matrix is ​​as follows:

[0104]

[0105] Where V represents the connection matrix, v i，j It represents the connection relationship between the i-th plot and the j-th plot, 1 represents connection, 0 represents no connection, and N represents the total number of plots in the distribution network planning area.

[0106] The expression of the plot attribution matrix is ​​as follows:

[0107]

[0108] Where B represents the land parcel ownership matrix, b i ∈{1,2,…,N set} represents the grid to which the ith plot belongs, which is the variable to be optimized. set Indicates the total number of grids.

[0109] Step S104: Taking the plot peak-to-valley difference matrix as input and the plot belonging matrix as the variable to be optimized, an integer programming model is established.

[0110] Step S105, taking the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization goal, and the number of plots in the grid and the load peak as constraints, solving the plot attribution matrix to obtain the solved target plot attribution matrix.

[0111] Among them, the optimization objective function corresponding to the optimization target is: Represents the sum of the peak-to-valley differences of each grid, where Set j represents the set of plots belonging to the jth grid;

[0112] The constraints include: lot quantity constraint and grid capacity constraint;

[0113] Among them, the number of plots is constrained as follows: N min ≤N i ≤N max , i∈{1, 2, …, N set},N i represents the number of plots in the i-th grid, N min represents the lower limit of the number of plots in the grid, N max Indicates the upper limit of the number of plots in the grid;

[0114] The grid capacity constraint is: S min represents the lower limit of the peak load in the grid, S max Indicates the upper limit of the peak load in the grid.

[0115] Step S106, dividing each block into a corresponding network according to the target block belonging matrix, and obtaining a block division result;

[0116] In order to ensure the accuracy of the land parcel division results, the present invention will further verify the correctness of the land parcel division results, namely, step S107 to step S109.

[0117] Step S107, determining whether all grids in the land parcel division result have only one connected subgraph, if yes, executing step S108;

[0118] Connected subgraph means: In graph theory, connected subgraph is based on the concept of connectivity. In an undirected graph G, if there is a path from vertex i to vertex j (of course there must be a path from j to i), then i and j are said to be connected. If any two points in the graph are connected, then the graph is called a connected graph. Extract some points from graph G. If any two of these points are connected, then the graph formed by these points is called a connected subgraph.

[0119] Step S108, determining whether the actual peak and valley time of the grid is the same as the corresponding value in the peak and valley time matrix, if yes, executing step S109;

[0120] Step S109: determine the plot division result as the target plot division result of the distribution network grid.

[0121] In summary, the present invention discloses a distribution network grid division method, which constructs a load matrix according to the load forecast information between plots in the distribution network planning area, and constructs a peak-valley time matrix according to the determined number of grids and the preset peak-valley time initial values, and determines the peak-valley difference of each plot at the peak time and the valley time according to the load matrix and the peak-valley time matrix to obtain the plot peak-valley difference matrix, and constructs a plot belonging matrix based on the connection matrix, taking the grids to which each plot belongs as the variable to be optimized, and taking the plot peak-valley difference matrix as input, and taking the plot belonging matrix as the variable to be optimized. Optimize variables, establish an integer programming model, take the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization target, take the number of plots in the grid and the load peak as constraints, solve the plot attribution matrix, obtain the solved target plot attribution matrix, divide each plot into the corresponding network according to the target plot attribution matrix, and obtain the plot division result. When all grids in the plot division result have only one connected subgraph, and the actual peak-to-valley time of the grid is the same as the corresponding value in the peak-to-valley time matrix, the plot division result is determined as the target plot division result of the distribution network grid. The present invention realizes the automatic division of plots, and can complete the distribution network grid division without manual intervention, thereby improving the efficiency of distribution network planning.

[0122] In addition, the present invention takes the load curve of the land into consideration, takes the minimum peak-to-valley difference as the goal, realizes grid division, and thus improves the utilization rate of the distribution network equipment.

[0123] To further optimize the above embodiment, step S108 may specifically include:

[0124] Draw the total load curve of each grid based on the plot division results;

[0125] Based on each of the total load curves, it is determined whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix.

[0126] To further optimize the above embodiment, step S107 may specifically include:

[0127] Perform a union-find test on the plot division results to determine the number of connected subgraphs under each grid;

[0128] Determine whether all grids have only one connected subgraph.

[0129] For the working principle of the union-find test, please refer to the existing mature solutions and will not be described here.

[0130] In practical applications, the number of connected subgraphs under each grid may be one or more. In the present invention, step S108 is executed only when the number of connected subgraphs under each grid is one.

[0131] For ease of understanding, the present invention provides a specific embodiment, see Figure 2 , a flowchart of a method for performing a union-find test on a plot division result to determine the number of connected subgraphs under each grid is disclosed in an embodiment of the present invention, the method comprising:

[0132] Step S201, determine whether the current edge traversed at the current moment is an initial edge, if yes, execute step S202, if no, execute step S203;

[0133] Each plot in the plot division result is regarded as a node, that is, each node corresponds to a plot in the plot division result, and two plots connected to each other in the same grid form an edge.

[0134] In this embodiment, one edge is selected from all the edges as the initial edge of the traversal.

[0135] In this embodiment, the edge traversed at the current moment is recorded as the “current edge”.

[0136] Step S202: arbitrarily select one of the two nodes of the current edge and set it as the upper node, and set the other node as the lower node, and continue to execute step S204;

[0137] Step S203, traverse the current edge according to the preset non-initial edge traversal scheme, and continue to execute step S204;

[0138] Step S204, determining whether the current edge is the last edge traversed;

[0139] Step S205: sort out the affiliation of each node in all the traversed edges, and obtain the number of connected subgraphs under each grid by counting.

[0140] Among them, each top-level node corresponds to a connected subgraph.

[0141] To further optimize the above embodiment, see Figure 3 , a flowchart of a method for traversing a current edge according to a preset non-initial edge traversal scheme when the current edge is not an initial edge is disclosed in an embodiment of the present invention, the method comprising:

[0142] Step S301: If the current edge is not the initial edge, determine whether there is a traversed node between the two nodes of the current edge. If not, execute step S302; if yes, execute step S303.

[0143] Step S302: arbitrarily select one of the two nodes of the current edge as the upper node, and set the other node as the lower node;

[0144] Step S303, determining whether the number of traversed nodes is one or two;

[0145] Step S304: when there is only one traversed node, the traversed node is set as the upper node, and the untraversed node is set as the lower node;

[0146] Step S305: when there are two traversed nodes, determine whether the top nodes of the two traversed nodes are the same, if not, execute step S306, if yes, execute step S307;

[0147] Step S306: arbitrarily select one of the two highest level nodes as the upper level node of the other highest level node;

[0148] Step S307: Determine that no additional node relationship needs to be set.

[0149] To further optimize Figure 1 For examples, see Figure 4 , another flow chart of a distribution network grid division method disclosed in an embodiment of the present invention, in Figure 1 Based on the embodiment shown, when the judgment in step S107 is no, the following further includes:

[0150] Step S110, extracting the maximum connected subgraph under each grid;

[0151] Among them, the largest connected subgraph under the grid is the connected subgraph with the largest number of plots under the grid.

[0152] Step S111, determine the latest land parcel attribution matrix.

[0153] Specifically, the corresponding variables of all the plots under the extracted maximum connected subgraphs in the plot attribution matrix are set as constants, and the variables corresponding to the plots other than the plots under the maximum connected subgraph in the plot attribution matrix are set as variables to be optimized, so as to obtain the latest plot attribution matrix.

[0154] After obtaining the latest land parcel attribution matrix in step S111, the process returns to step S104 to re-establish the integer programming model.

[0155] In this embodiment, when the judgment in step S108 is no, the following may also be included:

[0156] Step S112, updating the corresponding values ​​in the peak and valley time matrix with the actual peak and valley times;

[0157] When all values ​​in the peak and valley time matrix that are different from the actual peak and valley time of the grid are replaced, the process returns to step S102.

[0158] In summary, the present invention realizes the automatic division of land plots and can complete the distribution network grid division without human intervention, thereby improving the efficiency of distribution network planning.

[0159] In addition, the present invention takes the load curve of the land into consideration, takes the minimum peak-to-valley difference as the goal, realizes grid division, and thus improves the utilization rate of the distribution network equipment.

[0160] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0161] The embodiments of the present invention and their implementation are as follows:

[0162] Figure 5 This is a schematic diagram of the plot distribution in the planning area of ​​the embodiment of the present invention. The load peak in the area is 22.7MW, and the load peak-to-valley difference is 12.59MW. The area is divided into two grids, and the peak upper limit of each grid is 15MW, the peak lower limit is 10MW, the upper limit of the plot is 18, and the lower limit is 12. The plot division result is as follows Figure 6 As shown, grid 1 contains 17 plots, grid 2 contains 14 plots, and the load curves of each grid are as follows Figure 7 , Figure 8As shown in the figure, the load peak of grid 1 is 11.46MW, the peak-to-valley difference is 6.25MW, and the load factor is 68.92%; the load peak of grid 2 is 11.25MW, the peak-to-valley difference is 6.33MW, and the load factor is 70.22%; the sum of the peak-to-valley differences of the two grids is 12.59MW.

[0163] After implementing the automatic clustering method for distribution network grids, the sum of the peak-to-valley differences of the two grids is the same as the peak-to-valley difference of the total load. The peak-to-valley difference has reached the optimum, and load balancing is achieved in the planning stage.

[0164] Corresponding to the above method embodiment, the present invention also discloses a distribution network grid division system.

[0165] See also Fig. 9 , a schematic diagram of a structure of a distribution network grid division system disclosed in an embodiment of the present invention, the system comprising:

[0166] The first matrix construction unit 401 is used to construct a load matrix according to load forecast information between plots in the distribution network planning area, and to construct a peak-valley time matrix according to the determined number of grids and preset peak-valley time initial values;

[0167] The second matrix construction unit 402 is used to determine the peak-valley difference of each plot at the peak time and the valley time according to the load matrix and the peak time and valley time marked in the peak-valley time matrix, and obtain a plot peak-valley difference matrix;

[0168] The third matrix construction unit 403 is used to construct a plot belonging matrix by taking the grid to which each plot belongs as a variable to be optimized based on the connection matrix, wherein the connection matrix is ​​constructed based on the topological information between the plots in the distribution network planning area;

[0169] A model building unit 404 is used to take the plot peak-to-valley difference matrix as input and the plot belonging matrix as a variable to be optimized to build an integer programming model;

[0170] The matrix solving unit 405 is used to solve the plot ownership matrix by taking the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization target and the number of plots in the grid and the load peak as the constraint conditions to obtain the solved target plot ownership matrix;

[0171] A division unit 406 is used to divide each block into a corresponding network according to the target block belonging matrix to obtain a block division result;

[0172] A first judging unit 407 is used to judge whether all grids in the land parcel division result have only one connected subgraph;

[0173] A second judgment unit 408 is used to judge whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix when the first judgment unit 407 judges that the result is yes;

[0174] The division result determining unit 409 is used to determine the land parcel division result as the target land parcel division result of the distribution network grid when the second determining unit 408 determines that the result is yes.

[0175] In summary, the present invention discloses a distribution network grid division system, which constructs a load matrix according to the load forecast information between plots in the distribution network planning area, and constructs a peak-valley time matrix according to the determined number of grids and the preset peak-valley time initial values, and determines the peak-valley difference of each plot at the peak time and the valley time according to the peak time and the valley time marked in the load matrix and the peak-valley time matrix to obtain the plot peak-valley difference matrix, and constructs a plot belonging matrix based on the connection matrix, taking the grids to which each plot belongs as the variable to be optimized, taking the plot peak-valley difference matrix as input, and taking the plot belonging matrix as the variable to be optimized. Optimize variables, establish an integer programming model, take the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization target, take the number of plots in the grid and the load peak as constraints, solve the plot attribution matrix, obtain the solved target plot attribution matrix, divide each plot into the corresponding network according to the target plot attribution matrix, and obtain the plot division result. When all grids in the plot division result have only one connected subgraph, and the actual peak-to-valley time of the grid is the same as the corresponding value in the peak-to-valley time matrix, the plot division result is determined as the target plot division result of the distribution network grid. It can be seen from this that the present invention realizes the automatic division of plots, and the distribution network grid division can be completed without manual intervention, thereby improving the efficiency of distribution network planning.

[0176] It should be noted that for the specific working principles of each component in the system embodiment, please refer to the corresponding part of the method embodiment, which will not be repeated here.

[0177] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are 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 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 "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0178] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0179] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distribution network grid division method, characterized in that: include: Constructing a load matrix according to load forecast information between plots in the distribution network planning area, and constructing a peak-valley time matrix according to the determined number of grids and preset peak-valley time initial values; According to the load matrix and the peak and valley times marked in the peak and valley time matrix, the peak-valley difference of each plot at the peak time and the valley time is determined to obtain a plot peak-valley difference matrix; Based on the connection matrix, the grid to which each block belongs is used as a variable to be optimized to construct a block belonging matrix, wherein the connection matrix is ​​constructed based on the topological information between the blocks in the distribution network planning area; Taking the plot peak-to-valley difference matrix as input and the plot belonging matrix as the variable to be optimized, an integer programming model is established; Taking the minimum sum of the peak-to-valley differences of each grid in the integer programming model as the optimization goal, and the number of plots in the grid and the load peak as constraints, solving the plot ownership matrix to obtain the solved target plot ownership matrix; Divide each plot into a corresponding network according to the target plot belonging matrix to obtain a plot division result; Determine whether all grids in the land parcel division result have only one connected subgraph; If yes, determining whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix; If yes, the plot division result is determined as the target plot division result of the distribution network grid.

2. The method for dividing a distribution network into grids according to claim 1, characterized in that: The expression of the load matrix is ​​as follows: Where, E represents the load matrix, e i,j It represents the load power of the ith plot at time j, and N represents the total number of plots in the distribution network planning area.

3. The method for dividing a distribution network into grids according to claim 1, characterized in that: The expression of the peak-valley moment matrix is ​​as follows: Where, T represents the peak-valley time matrix, t i,peak represents the peak time of the ith grid, t i,valley represents the valley moment of the i-th grid, N set Indicates the total number of grids.

4. The method for dividing a distribution network into grids according to claim 1, characterized in that: The expression of the connection matrix is ​​as follows: Where V represents the connection matrix, v i,j It represents the connection relationship between the i-th plot and the j-th plot, 1 represents connection, 0 represents no connection, and N represents the total number of plots in the distribution network planning area.

5. The method for dividing a distribution network into grids according to claim 1, characterized in that: The expression of the plot peak-to-valley difference matrix is ​​as follows: Where D represents the peak-to-valley difference matrix of the plot, d i,j represents the peak-to-valley difference of the i-th plot in the j-th grid, Indicates that the i-th plot is at t j,peak Load power at time t j,peak represents the peak time of the jth grid, Indicates that the i-th plot is at t j,valley Load power at time t j,valley represents the valley moment of the jth grid; The expression of the plot attribution matrix is ​​as follows: Where B represents the land parcel ownership matrix, b i ∈{1,2,…,N set } represents the grid to which the ith plot belongs, which is the variable to be optimized. set Indicates the total number of grids.

6. The method for dividing the distribution network into grids according to claim 5, characterized in that: The optimization objective function corresponding to the optimization objective is: Represents the sum of the peak-to-valley differences of each grid, where Set j represents the set of plots belonging to the jth grid; The constraints include: lot quantity constraint and grid capacity constraint; The number of plots is constrained as follows: N min ≤N i ≤N max ,i∈{1,2,…,N set },N i represents the number of plots in the i-th grid, N min represents the lower limit of the number of plots in the grid, N max Indicates the upper limit of the number of plots in the grid; The grid capacity constraint is: S min represents the lower limit of the peak load in the grid, S max Indicates the upper limit of the peak load in the grid.

7. The method for dividing a distribution network into grids according to claim 1, characterized in that: The step of determining whether all grids in the land parcel division result have only one connected subgraph comprises: Performing a union-find test on the plot division results to determine the number of connected subgraphs under each grid; Determine whether all grids have only one connected subgraph.

8. The method for dividing a distribution network into grids according to claim 7, characterized in that: The step of performing a union-find test on the plot division result to determine the number of connected subgraphs under each grid includes: Determine whether the current edge traversed at the current moment is an initial edge, wherein the current edge is an edge formed between two interconnected plots in the same grid in the plot division result; If the current edge is the initial edge, any one of the two nodes of the current edge is selected as the upper node, and the other node is set as the lower node, and each of the nodes corresponds to a plot in the plot division result; If the current edge is not the initial edge, traversing the current edge according to a preset non-initial edge traversal scheme; Determine whether the current edge is the last edge traversed; If yes, the affiliation of each node in all the traversed edges is sorted out, and the number of connected subgraphs under each grid is obtained by counting, wherein each top-level node corresponds to a connected subgraph.

9. The method for dividing the distribution network into grids according to claim 8, characterized in that: If the current edge is not the initial edge, the step of traversing the current edge according to a preset non-initial edge traversal scheme includes: If the current edge is not the initial edge, determining whether there is a traversed node between two nodes of the current edge; If there is no traversed node, one of the two nodes of the current edge is randomly selected as the upper node, and the other node is set as the lower node; If there are traversed nodes, determine whether the number of traversed nodes is one or two; When there is only one traversed node, the traversed node is set as the parent node, and the untraversed node is set as the child node; When there are two traversed nodes, determine whether the top nodes of the two traversed nodes are the same; If they are not the same, one of the two top-level nodes is randomly selected as the parent node of the other top-level node; If they are the same, it is determined that no additional node relationship needs to be set.

10. The method for dividing a distribution network into grids according to claim 1, characterized in that: Also includes: When all grids in the land parcel division result do not have only one connected subgraph, extracting the largest connected subgraph under each grid; The corresponding variables of all the extracted plots under the maximum connected subgraph in the plot attribution matrix are set as constants, and the variables corresponding to the plots in the plot attribution matrix except the plots under the maximum connected subgraph are set as variables to be optimized, and the integer programming model is re-established by returning to the step.

11. The method for dividing a distribution network into grids according to claim 1, characterized in that: The step of determining whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix comprises: Draw a total load curve of each grid based on the plot division result; Based on each of the total load curves, it is determined whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix.

12. The method for dividing a distribution network into grids according to claim 1, characterized in that: Also includes: When the actual peak and valley moments of the grid are different from the corresponding values ​​in the peak and valley moment matrix, the corresponding values ​​in the peak and valley moment matrix are updated with the actual peak and valley moments, and the peak and valley difference matrix of the plot is returned to be recalculated.

13. A distribution network grid division system, characterized in that: include: A first matrix construction unit is used to construct a load matrix according to load forecast information between plots in a distribution network planning area, and to construct a peak-valley time matrix according to a determined number of grids and preset peak-valley time initial values; The second matrix construction unit is used to determine the peak-valley difference of each plot at the peak time and the valley time according to the load matrix and the peak time and valley time marked in the peak-valley time matrix, and obtain a plot peak-valley difference matrix; A third matrix construction unit is used to construct a plot belonging matrix by taking the grids to which each plot belongs as variables to be optimized based on a connection matrix, wherein the connection matrix is ​​constructed based on topological information between plots in the distribution network planning area; A model building unit, used to take the plot peak-to-valley difference matrix as input and the plot belonging matrix as a variable to be optimized, and to build an integer programming model; A matrix solving unit is used to solve the plot ownership matrix by taking the minimum sum of peak-to-valley differences of each grid in the integer programming model as the optimization target and the number of plots in the grid and the load peak as the constraint conditions to obtain the solved target plot ownership matrix; A division unit, used to divide each block into a corresponding network according to the target block belonging matrix, and obtain a block division result; A first judging unit is used to judge whether all grids in the land parcel division result have only one connected subgraph; A second judgment unit is used to judge whether the actual peak and valley moments of the grid are the same as the corresponding values ​​in the peak and valley moment matrix when the first judgment unit judges that the value is yes; A division result determination unit is used to determine the plot division result as the target plot division result of the distribution network grid when the second determination unit determines that the result is yes.

Images