Green electricity physical rapid tracing method and system based on graph theory improved electrical subdivision method

Abstract

The invention discloses a green electricity physical rapid traceability method and system based on a graph theory improved electrical subdivision method, and relates to the technical field of energy and potential assessment, and the method comprises the steps: obtaining a power flow state of a power system through solving a power flow equation or a state estimation program; generating a directed graph according to the power flow state of a system branch, and simplifying nodes and branches of each power generation side and each load side under the condition of conforming to the basic principle of electrical subdivision; generating a node output power branch incidence matrix and a node input power branch incidence matrix to obtain a tracking sequence; generating a subdivision factor matrix and a contribution share matrix according to the tracking sequence and an electrical subdivision principle; and inversely changing the simplified parameter into an actual parameter to obtain a green electricity physical consumption process. The method provided by the invention not only overcomes the problem that the traditional power flow subdivision lacks an electrical theoretical basis, but also improves the problem that the operand is too large when facing a complex network in an electrical subdivision method, and provides a feasible scheme for realizing green electricity physical traceability.

Description

Technical Field

[0001] The present invention relates to the technical field of energy and potential assessment, and particularly relates to a green electricity physical rapid traceability method and system based on an improved electrical dissection method of graph theory. Background Art

[0002] In China, with the rapid development of the renewable energy industry, green electricity trading and traceability have become increasingly important. For example, the Beijing Power Exchange Center has established a green electricity trading blockchain traceability certification system to support the national green electricity trading pilot work and provide important vouchers for completing renewable energy consumption indicators and domestic carbon emission verification.

[0003] However, the above green electricity traceability system is based on the environmental attributes of green electricity, that is, when a new energy power plant signs a contract with a large user, the large user holds the corresponding number of green certificates, and the holding amount of green certificates represents the green electricity consumption level of the user. Obviously, relying solely on the signing of contracts as the basis for green certificate consumption is unreasonable and illogical.

[0004] Therefore, a traceability system based on the physical attributes of green electricity is needed. However, power flow tracing is based on the proportional distribution principle, lacking both electrical theory basis and the coupling relationship between active and reactive power. And the complexity of the electrical dissection theory is exponential when finding the dissection path. When facing a complex network, the calculation process takes a lot of time, and all generator nodes need to be traversed to obtain the final contribution share. Summary of the Invention

[0005] The problem to be solved by the present invention is: aiming at the deficiencies in the above background art, to provide a green electricity physical rapid traceability method and system based on an improved electrical dissection method of graph theory, which combines the power flow tracing algorithm with the basic principles of electrical dissection to solve the problems of difficult and slow green electricity physical traceability, and provides a feasible algorithm and solution for green electricity physical traceability.

[0006] The present invention adopts the following technical solutions: A green electricity physical rapid traceability method based on an improved electrical dissection method of graph theory, comprising the following steps:

[0007] Step 1, according to the grid network topology information, power data of the power generation side nodes and the load side nodes, obtain the operating state of the power system by solving the power flow equation or through a state estimation program;

[0008] Step 2, according to the operating state of the power system obtained in Step 1, taking the active power direction on each branch as the reference, structure the grid network topology into a directed graph, and generate an adjacency matrix of the phasor diagram; the weight parameter of each arc in the directed graph is the complex power of the corresponding branch in the grid network topology, and the generator and the load are respectively transformed into an injection source in the directed graph;

[0009] Step 3: According to the directed graph obtained in Step 2, simplify the power generation nodes and load nodes connected to the same node into a network net input node or net output node according to the electrical dissection principle. Take the generator nodes not connected to the same node as net input nodes and the load nodes as net output nodes;

[0010] Step 4: Find the source node according to the adjacency matrix of the directed graph;

[0011] Step 5: Perform iterative tracking based on the source node found in Step 4, delete the parameters corresponding to the source node in the adjacency matrix and then determine the new source node until only one element 0 remains in the adjacency matrix to determine the tracking order;

[0012] Step 6: According to the tracking order determined in Step 5 and the electrical dissection principle, generate a dissection factor matrix A composed of the ratio of the complex power flowing through the line to the total complex power flowing through the upstream node and the ratio of the total complex power flowing through the net output node pair to the upstream node where it is located;

[0013] Step 7: According to the dissection factor matrix A, generate a contribution share matrix B of the net input node to the total power flowing through the downstream node, and re-convert the net input and output nodes into the initial generator and load node data according to the initial power flow state to obtain the tracing process of green electricity.

[0014] As a further optimization scheme of the green electricity physical rapid tracing method based on the graph theory improved electrical dissection method, in Step 1, by solving the power flow equation dig(U * )YU = P - jQ or by performing estimation algorithm processing on z = h(x) + v through the state estimation program, the voltage of the n-node system is obtained;

[0015] where P represents the active power, j represents the imaginary unit, Q represents the reactive power, U * represents the conjugate complex number of the node voltage, Y represents the node admittance matrix, h(x) represents the state equation, v represents the measurement noise, and z represents the actual measurement value.

[0016] As a further optimization scheme of the green electricity physical rapid tracing method based on the graph theory improved electrical dissection method, in Step 2, based on the node admittance matrix Y, generate the adjacency matrix of the phasor diagram of the electrical network structure. The specific steps are as follows:

[0017] Step 2.1: Remove the diagonal elements of the node admittance matrix Y and take its lower triangular part to generate matrix G.

[0018] Step 2.2: Start from the second row and find the non-zero elements in each row. For the non-zero element NZ 2,j , calculate its P through the power flow equation solved in Step 1 2,j If P2,j If it is > 0, then the original non - zero element NZ in the G matrix at the 2nd row and jth column 2,j will be changed to 1. Otherwise, the original non - zero element NZ in the G matrix at the 2nd row and jth column 2,j will be changed to 0, and G j,2 will be changed to 1.

[0019] Step 2.3: Traverse each row according to the process in Step 2.2 and update matrix G until all rows are traversed.

[0020] As a further optimization scheme of the green - electricity physical rapid traceability method based on the graph - theory improved electrical dissection method, in Step 3, directly accumulate the direct power of the generator and the load connected to the same node, and then judge the nature of the node in the phase diagram of the electrical network. Since the generator is directly connected to the node in the electrical network, this direct - accumulation method conforms to the 5 basic principles of electrical dissection.

[0021] Use P G and P L to represent the power output of the generator at this node and the load power of this node respectively. If P G - P L > 0, then this node is regarded as a net - output node to participate in the subsequent operations; otherwise, it is a net - input node.

[0022] As a further optimization scheme of the green - electricity physical rapid traceability method based on the graph - theory improved electrical dissection method, in Step 5, through the adjacency matrix G generated in the above - mentioned scheme, and then obtain the tracking order of the system by iterative deletion of the matrix. The specific method is as follows:

[0023] Step 5.1: Find the columns in the directed - graph adjacency matrix G of the area to be dissected where all elements are 0, and let it be the first tracking node;

[0024] Step 5.2: Delete the rows and columns corresponding to the tracking node, and repeat Step 5.1 to continue searching until there is only one element left in the adjacency matrix G, obtaining a new matrix G';

[0025] Step 5.3: Generate a tracking - order matrix SQ = [k1 … k i according to the order in which the tracking nodes are found successively, where k i represents the i - th tracking node.

[0026] As a further optimization scheme of the green - electricity physical rapid traceability method based on the graph - theory improved electrical dissection method, in Step 6, according to the tracking order obtained in the above - mentioned scheme and the voltage states of each node, obtain the dissection - factor matrix A while following the principles of electrical dissection:

[0027]

[0028] Among them, A M and A L represent the line dissection matrix and the load dissection matrix respectively.

[0029] First, for A M there is S l = A M * S, where S is a matrix with n rows and 1 column, n is the number of nodes, and the elements in the S matrix are obtained from the tracking sequence matrix SQ obtained in step 4: S i,1 = |Total power flowing through S 1，i node|.

[0030] S l is a matrix with m rows and 1 column, m is the number of branches in the directed graph, and its elements are the magnitudes of the complex power flowing through each branch based on the active power flow direction.

[0031] The specific steps to find the element values in A M are as follows:

[0032] Step 6.1: For the assignment of the elements in the first row of A M , first find the node b 1 i where power flows in on the first branch;

[0033] Step 6.2: Conduct electrical dissection analysis for node b 1 i . Find all the upstream nodes and all the downstream nodes of node in the directed graph G, and establish an electrical dissection model based on the impedance data between each node in the power grid structure;

[0034] Step 6.3: Solve the electrical dissection model in step two to obtain the total power flowing into node and the dissection coefficient k1 of the first branch, and the rest of the elements in the first row are all 0.

[0035] Repeat the above steps until each branch has been processed.

[0036] Similarly, the net output part A L in the dissection factor matrix can be formed. Let the arrangement order of the net output vector S L be the same as that of S. Then from S L = A L * S, it can be seen that A L will be a diagonal matrix, and the element values in the matrix are as follows:

[0037]

[0038] For AL Merge with A M The complete dissection factor matrix A can be obtained by merging.

[0039] As a further optimization scheme of the green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory, in step 7, the formation method of the contribution share matrix B of the generator power to the total flowing power of its downstream nodes is as follows:

[0040] Let S G be the power generation power vector (if node i is not an S Gi generator node, then S Gi = 0), S is the total flowing power vector of the nodes, and S and S G have the same node arrangement order; then the matrix B can be defined as S = B * S G .

[0041] According to the principle of downstream tracking, for a certain node i, only the upstream node generator of it can allocate the total power flowing through it. Therefore, the upper triangular matrix elements in matrix B that reflect the influence of downstream nodes on upstream nodes are all zero.

[0042] If node i is a net generator node, the corresponding diagonal element in matrix B is 1, otherwise it is 0. Non-generator nodes will not have any influence on their downstream nodes, that is, the elements in the corresponding columns of the B matrix are always 0.

[0043] Therefore, matrix B can be calculated according to the following formula:

[0044]

[0045] In the formula, k < i means that node k is the upstream node of node i; k > i means that node k is the downstream node of node i; j ∈ i means that power is injected into node i through line j; A M (j, m) corresponds to the only non-zero element in the j-th row of A l ; m is the upstream node of line j; B mk is the element that has been calculated in the B matrix, representing the contribution share of generator k to the total flowing power of node m; A M (j, m) * B mk is the contribution share of generator k to the total power injected into node i through node m and line j.

[0046] Because there is S L = A L * S, S = B * S G , so there is S L = A L * B * S G , where A L * B is the contribution share matrix AP of the net input node to the net output node.

[0047] As a further optimization scheme of the green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory, based on the contribution share matrix AP of the net input nodes to the net output nodes in the above steps, further processing and simplification of AP are required to obtain the final traceability matrix AP' of the power system load to the generators.

[0048] The expression of AP' is as follows:

[0049]

[0050] Among them, dig(M) represents the diagonal matrix composed of the diagonal elements of matrix M; S Gi and S Li represent the generator power and load power of node i respectively.

[0051] The technical solution of the present invention further includes: a green electricity physical rapid traceability system based on the improved electrical dissection method of graph theory for implementing any of the above green electricity physical rapid traceability methods, including: a data acquisition module, a model building module, and an algorithm solving module;

[0052] The data acquisition module is used to collect the topological information of the regional distribution network grid, the load data on the user side, and the power generation data on the power generation side that need to be traced for green electricity;

[0053] The model building module is used to solve the elements of the dissection factor matrix A, find all the upstream nodes and all the downstream nodes of a certain node, and construct an electrical dissection model in combination with the network architecture data and the real-time power flow data;

[0054] The algorithm solving module is used to receive the data collected by the data acquisition module, call the electrical dissection model constructed by the model building module, calculate the element values in the dissection factor matrix A, generate the contribution share matrix B of the net input nodes to the total power flow of the downstream nodes according to the dissection factor matrix A, and perform processing according to the value of A and the solution formula of the B matrix to obtain the traceability matrix AP', which is used to obtain the traceability process of green electricity.

[0055] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0056] 1. The present invention proposes a green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory. The electrical dissection method is used to consider the coupling relationship between active power and reactive power, providing a theoretical support for green electricity traceability, and a fast solution method for green electricity traceability of the entire network is provided through the fast iteration method of graph theory.

[0057] 2. The green power physical rapid traceability system constructed by the present invention includes a data acquisition module, a model building module, and an algorithm solving module. Parameters such as users, power generation side, and network branch impedance in the network to be dissected are collected through the data acquisition module and input into the model building module to establish corresponding mathematical models. Then, the established models are solved through the algorithm solving module to provide a reference solution for future green certificate issuance and carbon quota allocation. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is a flow chart of the green power physical rapid traceability method based on the improved electrical dissection method of graph theory of the present invention;

[0059] Figure 2 is a schematic diagram of the upstream and downstream nodes of the basic electrical model of the present invention;

[0060] Figure 3 is a schematic diagram of the upstream and downstream nodes of the dissected basic electrical model of the present invention;

[0061] Figure 4 is a block diagram of the green power physical rapid traceability system based on the improved electrical dissection method of graph theory of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0062] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the application will be further elaborated in detail below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments involved in the present invention. All non-innovative embodiments made by other researchers in the field based on this embodiment fall within the protection scope of the present invention. At the same time, for the step numbers in the embodiments of the present invention, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0063] In an embodiment of the present invention, a green power physical rapid traceability method based on an improved electrical dissection method of graph theory, as Figure 1 shown, includes the following steps:

[0064] Step 1, obtain the system state by solving the power flow equation or the state estimation program according to the grid network topology information, power data of the power generation side nodes and the load side nodes;

[0065] Step 2, according to the power system operation state obtained in Step 1, structure the grid network topology into a directed graph based on the active power direction on each branch. The weight parameter of each arc in the directed graph is the complex power of the corresponding branch in the original network topology, and both the generator and the load are transformed into an injection source in the directed graph.

[0066] Specifically, in Step 1, by solving the power flow equation dig(U *)YU = P - jQ, or the voltage of the n - node system is obtained by processing the estimation algorithm for z = h(x)+v through a state - estimation program.

[0067] Specifically, in step 2, based on the nodal admittance matrix Y, an adjacency matrix of the phasor diagram of the electric network structure is generated. The specific operation steps are as follows:

[0068] Step 2.1: Remove the diagonal elements of the nodal admittance matrix Y, and take its lower - triangular part to generate matrix G.

[0069] Step 2.2: Starting from the second row, find the non - zero elements in each row. For the non - zero element NZ 2,j , calculate its P 2,j If P 2,j > 0, then change the value of the original non - zero element NZ 2,j in the G matrix at the 2 - row and j - column to 1. Otherwise, change the value of the original non - zero element NZ 2,j in the G matrix at the 2 - row and j - column to 0, and G j,2 becomes 1.

[0070] Step 2.3: Traverse each row according to the process of step 2.2, and update matrix G until all rows are traversed.

[0071] Specifically, in step 3, according to the directed graph obtained in step 2, the power - generation nodes and load nodes connected to the same node are simplified into a network net - input node or net - output node according to the principle of electrical dissection. The remaining generator nodes are net - input nodes, and the load nodes are net - output nodes.

[0072] Directly accumulate the direct powers of the generator and the load connected to the same node to judge the node property in the phasor diagram of the electric network. Since the generator is directly connected to the node in the electric network, this direct - accumulation method conforms to the five basic principles of electrical dissection.

[0073] If P G - P L > 0, then this node is regarded as a net - output node to participate in the subsequent operations. Otherwise, it is a net - input node.

[0074] Specifically, in step 4, according to the directed graph in step 3, and find the source point based on the adjacency matrix of the directed graph, and start the iterative operation.

[0075] Specifically, in step 5, delete the parameters corresponding to the source point in the source - point adjacency matrix determined in step 4, then determine the new source point and repeat the above process until only one element 0 remains in the adjacency matrix, and finally determine the tracking order.

[0076] For the adjacency matrix G generated in the above steps, the following processing is performed: First, find the columns with all elements being 0, and let it be the first tracking node; then delete the rows and columns corresponding to this node, and continue to search in the same way as the previous step until G has only one element left; record the order of the tracking nodes to form the tracking order matrix SQ.

[0077] In this embodiment, taking a merged three-node system as an example, the specific steps are as follows:

[0078] Step 5.1: The adjacency matrix G of the directed graph of the area to be dissected is generated as follows:

[0079]

[0080] Step 5.2: Find the node corresponding to a column with all elements being 0 in the adjacency matrix G. This node is the source node, which means that all the power given by the upstream net input node above this node flows out of the system.

[0081] Find the first source node After that, delete the row and column where node k1 is located, and the new matrix G' obtained is:

[0082]

[0083] Step 5.3: If the number of rows in the obtained G' is not 1, return to Step 4-2; if the number of its rows is only one, then generate the sequence matrix SQ = [k1 … k i according to the order in which the source nodes are found successively.

[0084] Specifically, in Step 6, according to the tracking order determined in Step 5 and the electrical dissection principle, generate the dissection factor matrix A composed of the ratio of the complex power flowing through the line to its upstream nodes and the total complex power flowing through the upstream nodes of the net output node to its upstream nodes.

[0085] For obtaining the A in the dissection factor matrix A M , the specific element steps are as follows:

[0086] Step 6.1: First, find all the upstream nodes of the outflow node in this branch, and then find all the downstream nodes of the outflow node in this branch to construct an electrical dissection model. Now, the method for specifically evaluating the elements of A in the dissection factor matrix is illustrated by a basic electrical model. M Assume that the branch corresponding to the impedance Z1 for which the element to be obtained is located, and the upstream and downstream nodes of the basic electrical model are as Figure 2 shown. According to the five principles of electrical dissection, dissect the basic electrical model, and the result is as Figure 2 shown.

[0087] Among them, Z' = γ1Z, Z'' = γ2Z, where Z, Z', and Z'' are the impedances of the corresponding upstream and downstream branches respectively, γ1 and γ2 are both positive real numbers, and Z' / / Z'' = Z.

[0088] Step 6.2: γ1 in this basic electrical model is the M corresponding element value obtained in [specific context], and according to the requirements of electrical partitioning, the basis for determining γ1 is: to minimize the modulus value of ΔS after partitioning the branch, and also Based on this, there is an objective function:

[0089]

[0090] where P and P1 are the active powers of the upstream and downstream branches respectively, Q and Q1 are the reactive powers of the upstream and downstream branches respectively, and γ is the partitioning coefficient of the upstream branch.

[0091] After simplification, it can be obtained:

[0092]

[0093] Based on this, it can be obtained that when the objective function takes the minimum value.

[0094] In the case of two upstream nodes, the method of branch equivalence can be used to equivalently transform the impedances of the two branches into parallel operation, and the upstream node voltage only needs to satisfy the total current equivalence. Based on this, the two upstream nodes can be equivalently transformed into a single node, and the partitioning model can be solved according to the above model. Finally, the contribution factors of each upstream node to the downstream branch to be solved are accumulated to obtain the value of the corresponding element in the partitioning factor matrix.

[0095] By analogy, the solution formula for the elements in the partitioning factor matrix in the case of multiple upstream nodes can be obtained, and it can be proved that under the five basic principles of electrical partitioning, all the absorbed powers on the load side can be completely traced back to the power generation side.

[0096] Similarly, the net output part A in the partitioning factor matrix can be formed L : Let the arrangement order of the net output vector S L be the same as that of S, then from S L = A L *S, it can be seen that A L will be a diagonal matrix, and the element values in the matrix are as follows:

[0097]

[0098] Combining A L with A M can obtain the complete partitioning factor matrix A.

[0099] Specifically, in step 7, according to the matrix A generated in step 6, a contribution share matrix B of the net input node to the total flowing power of its downstream nodes is generated. Then, based on the initial power flow state, the net input and output nodes are reconverted into the initial generator and load node data. Finally, the tracing process of green electricity is obtained, and the specific steps are as follows:

[0100] Step 7.1. Let S G be the power generation vector (if node i is not an S Gi generator node, then S Gi = 0), S is the total flowing power vector of the nodes, and S and S G have the same node arrangement order; then the matrix B can be defined as S = B * S G .

[0101] According to the principle of downstream tracking, for a certain node i, only the upstream node generators of it can allocate the total power flowing through it. Therefore, the elements of the upper triangular matrix in matrix B that reflect the influence of downstream nodes on upstream nodes are all zero.

[0102] If node i is a net generator node, the corresponding diagonal element in matrix B is 1, otherwise it is 0.

[0103] Non-generator nodes will not have any influence on their downstream nodes, that is, the elements of the corresponding columns in the B matrix are always 0.

[0104] Therefore, matrix B can be calculated according to the following formula:

[0105]

[0106] In the formula, k < i means that node k is an upstream node of node i; k > i means that node k is a downstream node of node i; j ∈ i means that power is injected into node i through line j; A M (j, m) corresponds to the only non-zero element in the j-th row of A l ; m is the upstream node of line j; B mk is the element that has been calculated in the B matrix, representing the contribution share of generator k to the total flowing power of node m; A M (j, m) * B mk is the contribution share of generator k to the total power injected into node i through node m and line j.

[0107] Because there is S L = A L * S, S = B * S G , so there is S L = A L * B * S G , where A L * B is the contribution share matrix AP of the net input node to the net output node.

[0108] Step 7.2: The AP needs to be further processed and simplified to obtain the final traceability matrix AP' of the power system load to the generator.

[0109] The expression of AP' is as follows:

[0110]

[0111] In an embodiment of the present invention, a comprehensive user cost calculator considering carbon emissions is further provided, as Figure 2 shown. The calculator includes: a data acquisition module, a model building module, and an algorithm solving module.

[0112] The data acquisition module is used to collect the grid topology information of the regional distribution network, the load data on the user side, and the power generation data on the power generation side that need to be traced for green electricity.

[0113] The model building module is used to solve the elements of the dissection factor matrix A. First, find all the upstream nodes and all the downstream nodes of the inflow node of the branch corresponding to the element to be solved in the A matrix, and construct a corresponding electrical dissection model in combination with the network architecture data and the real-time power flow data.

[0114] The algorithm solving module is used to receive the data collected by the data acquisition module, call the model building module to construct the electrical dissection model, calculate the element values in the dissection matrix A under the five basic principles of electrical dissection, solve the matrix AP according to the values of A and the solution formula of the B matrix, and finally re-convert the net output nodes corresponding to the rows of AP and the net input nodes corresponding to the columns into the actual load-side data and power generation-side data according to the initial conditions, so as to obtain the final traceability matrix AP'.

[0115] In an embodiment of the present invention, a green electricity physical rapid traceability system based on an improved graph theory electrical dissection method is further provided, as Figure 4 shown, which is used to implement the above-mentioned green electricity physical rapid traceability method, and includes: a data acquisition module, a model building module, and an algorithm solving module;

[0116] Among them, the data acquisition module is used to collect the grid topology information of the regional distribution network, the load data on the user side, and the power generation data on the power generation side that need to be traced for green electricity;

[0117] The model building module is used to solve the elements of the dissection factor matrix A, find all the upstream nodes and all the downstream nodes of a certain node, and construct an electrical dissection model in combination with the network architecture data and the real-time power flow data;

[0118] The algorithm solving module is used to receive the data collected by the data acquisition module, call the model building module to build the model of electrical dissection, calculate the element values in the dissection factor matrix A, generate the contribution share matrix B of the net input node to the total flow power of the downstream nodes according to the dissection factor matrix A, and process according to the value of A and the solution formula of the B matrix to obtain the traceability matrix AP', which is used to obtain the traceability process of green electricity.

[0119] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A green electricity physical rapid traceability method based on an improved electrical dissection method of graph theory, characterized in that, It includes the following steps: Step 1: According to the power grid network topology information, the power data of the power generation side nodes and the load side nodes, obtain the operating state of the power system by solving the power flow equation or through a state estimation program; Step 2: Based on the operating state of the power system obtained in Step 1, taking the active power direction on each branch as the benchmark, transform the power grid network topology into a directed graph, and generate an adjacency matrix of the phasor diagram; the weight parameter of each arc in the directed graph is the complex power of the corresponding branch in the power grid network topology, and the generators and loads are respectively transformed into an injection source in the directed graph; Step 3: According to the directed graph obtained in Step 2, simplify the power generation nodes and load nodes connected to the same node into a network net input node or net output node according to the electrical partitioning principle, take the generator nodes not connected to the same node as net input nodes, and the load nodes as net output nodes; Step 4: According to the adjacency matrix of the directed graph, find the source point; Step 5: Perform iterative tracking based on the source point found in Step 4, delete the parameters corresponding to the source point in the adjacency matrix and then determine the new source point until only one element 0 remains in the adjacency matrix, and determine the tracking order; Step 6: According to the tracking order determined in Step 5 and the electrical partitioning principle, generate a partitioning factor matrix A composed of the ratio of the complex power flowing through the line to the upstream node and the total complex power flowing through the upstream node by the net output node pair; Step 7: According to the partitioning factor matrix A, generate a contribution share matrix B of the net input node to the total power flowing through the downstream node, and re-transform the net input and output nodes into the initial generator and load node data according to the initial power flow state to obtain the tracing process of green electricity.

2. The green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 1, characterized in that In Step 1, the power flow equation is expressed as: dig(U * ) YU = P - jQ where P represents active power, j represents the imaginary unit, Q represents reactive power, and U * represents the conjugate complex number of the nodal voltage, and Y represents the nodal admittance matrix; For the state estimation program, perform estimation algorithm processing on the following formula: z = h(x) + v where h(x) represents the state equation, v represents the measurement noise, z represents the actual measurement value, and the voltage of the n-node system is obtained.

3. The green power physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 2, characterized in that, In Step 2, to transform the power grid network topology into a directed graph and generate an adjacency matrix of the phasor diagram based on the nodal admittance matrix Y, the method is as follows: Step 2.1: Remove the diagonal elements of the nodal admittance matrix Y, and take the lower triangular part of the nodal admittance matrix to generate a matrix G; Step 2.2: Starting from the second row of matrix G, find the non-zero elements in each row. For the non-zero element NZ 2,j , view P through the power flow equation solved in Step 1 2,j ; if P 2,j > 0, then change the value of the original non-zero element NZ 2,j in the j-th column of the second row in matrix G to 1; otherwise, change the value of the original non-zero element NZ 2,j in the j-th column of the second row in matrix G to 0, and G j,2 becomes 1; Step 2.3: According to the method in Step 2.2, traverse each row and update the matrix G until all rows are traversed.

4. The green power physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 2, characterized in that In step 3, directly accumulate the power of the generator and the load connected to the generator at the same node, and determine the nature of the node. If P G -P L > 0, the node is used as a net output node; otherwise, it is a net input node. Among them, P G and P L respectively represent the power output of the generator at this node and the load power of this node.

5. The green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 2, characterized in that, In Step 5, through the adjacency matrix G of the phasor diagram generated in Step 2, determine the tracking order through iterative deletion of the matrix, and the method is as follows: Step 5.1: Find the columns in the adjacency matrix G of the directed graph in the area to be partitioned where all elements are 0, and let it be the first tracking node; Step 5.2: Delete the rows and columns corresponding to the tracking node, and repeat Step 5.1 to continue searching until only one element remains in the adjacency matrix G, and obtain a new matrix G'; Step 5.

3. Generate a tracking sequence matrix SQ = [k1…k i , where k i represents the i-th tracking node.

6. The green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 5, characterized in that In Step 6, according to the tracking order determined in Step 5 and the voltage state of each node, obtain the partitioning factor matrix A under the principle of following electrical partitioning, which is expressed as: Among them, A M and A L represent the line partition matrix and the load partition matrix respectively; For A M , there is S l = A M * S; S is a matrix of n rows and 1 column, where n is the number of nodes, and the elements in the S matrix are obtained from the tracking sequence matrix SQ as follows: S i,1 = |Total power flowing through the S 1，i node|; S l is a matrix of m rows and 1 column, where m is the number of branches in the directed graph, and the S l elements are the magnitudes of the complex powers flowing through each branch based on the active power flow direction; For A L , there is S L = A L * S; S L is the net output vector, arranged in the same order as S, obtained from S L = A L * S to get A L is a diagonal matrix, and the elements (A L ) ii take the following values: Merge A L with A M to obtain the complete sub - division factor matrix A.

7. The green power physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 6, characterized in that, Find A M The method for the element values in Step 6.1: For A M Assign values to the elements in the first row of 1 i ; find the node b with incoming power in the first branch Step 6.

2. For node b 1 i Perform electrical dissection analysis, and find all upstream nodes and all downstream nodes of the node in the directed graph G, and establish an electrical dissection model based on the impedance data between nodes in the power grid architecture; Step 6.

3. Solve the electrical dissection model in Step 6.2 to obtain the nodes Total power flowing in The dissection coefficient k1 of the first branch And the rest of the elements in the first row are all 0; Step 6.4: Repeat Steps 6.1 to 6.3 until each branch is processed.

8. The green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 6, characterized in that In step 7, according to the dissection factor matrix A, a contribution share matrix B of the total power flow of the net input nodes to the downstream nodes is generated as follows: Let S G be the power generation power vector. If node i is not a generator node, then S Gi = 0. S is the total power flow vector of the node. S and S G have the same node arrangement order. Define the matrix B as S = B * S G ; The elements of the upper triangular matrix in matrix B that reflect the influence of downstream nodes on upstream nodes are all zero; if node i is a net generator node, the corresponding diagonal element in matrix B is 1, otherwise it is 0; non-generator nodes do not have any influence on downstream nodes, and the elements in the corresponding columns of matrix B are always 0; Matrix B is calculated as follows: In the formula, k < i means that node k is an upstream node of node i; k > i means that node k is a downstream node of node i; Power is injected into node \(i\) through line \(j\) as \(j\in i\); \(A\) M (\(j\), \(m\)) corresponds to \(A\) M The only non - zero element in the \(j\)-th row of m is the upstream node of line j; B mk is an element that has been calculated in the B matrix, representing the contribution share of generator k to the total flowing power of node m; A M (j, m)B mk is the contribution share of generator k to the total power injected into node i through node m and line j; Based on S L = A L * S, S = B * S G , there is S L = A L * B * S G , where A L * B is the contribution share matrix AP of the net input node to the net output node.

9. The green electricity physical rapid traceability method based on the improved electrical dissection method of graph theory according to claim 8, characterized in that, According to the contribution share matrix AP of the net input nodes to the net output nodes, a tracing matrix AP' of the power system load to the generator is obtained, and the expression is as follows: where, dig(M) represents the diagonal matrix formed by the diagonal elements of matrix M; S Gi and S Li represent the generator power and load power of node i, respectively.

10. A green electricity physical rapid traceability system based on an improved electrical dissection method of graph theory, which is used to implement the green electricity physical rapid traceability method described in any one of claims 1 to 9, and is characterized in that, Including: Data acquisition module, model building module, algorithm solving module; The data acquisition module is used to collect the topological information of the regional distribution network grid, the load data on the user side, and the power generation data on the power generation side that need to be traced for green power; The model building module is used to solve the elements of the dissection factor matrix A, find all the upstream nodes and all the downstream nodes of a certain node, and construct an electrical dissection model in combination with the network architecture data and the real-time power flow data; The algorithm solving module is used to receive the data collected by the data acquisition module, call the model building module to construct the electrical dissection model, calculate the element values in the dissection factor matrix A, generate a contribution share matrix B of the total power flow of the net input nodes to the downstream nodes according to the dissection factor matrix A, and obtain the tracing matrix AP' according to the value of A and the solution formula of matrix B, which is used to obtain the tracing process of green power.

Images