Energy interconnection scheduling method and system for multi-region power distribution network

Abstract

The invention discloses an energy interconnection scheduling method and system for a multi-region power distribution network, and relates to the technical field of electric power, and the method comprises the steps: determining a radiation topological structure of the multi-region power distribution network, and the radiation topological structure comprises a main line, branch nodes and branch lines; establishing a connection relation and a power upstream and downstream relation of each node of the power distribution network, and deducing a linear relation between a voltage square term and node load power; determining the distribution of energy interconnection nodes based on the voltage improvement degree and the control node number constraint; and in combination with the linearization derivation result and the energy interconnection node distribution, hierarchical scheduling decision-making including upper decision-making and lower decision-making is carried out, so that the balance of global voltage optimization and local economy optimization is achieved, and the technical effects of improving the safety, economy and reliability of the operation of the power distribution network are achieved.

Description

Technical Field

[0001] The present invention relates to the field of power technology, and particularly to an energy interconnection scheduling method and system for a multi-region distribution network. Background Art

[0002] With the wide application of distributed energy, more and more regional distribution network energy interconnection systems are connected to the distribution network. These systems can provide active and reactive power support, but their connection locations and operation strategies have a significant impact on the performance of the distribution network. Since most existing distribution networks adopt a radial structure, their topological structures are complex, with numerous nodes, and there are a large number of branches and sub-branches. Traditional scheduling methods are difficult to effectively handle the access and optimization problems of multi-region distribution network energy interconnection systems. Summary of the Invention

[0003] The present invention provides an energy interconnection scheduling method and system for a multi-region distribution network to solve the technical problems of unreasonable access positions of energy interconnection systems and imperfect scheduling methods in the prior art, achieve a balance between global voltage optimization and local economic optimization, and improve the technical effects of the safety, economy, and reliability of the operation of the distribution network.

[0004] In a first aspect, the present invention provides an energy interconnection scheduling method for a multi-region distribution network, wherein the method includes: Determine the radial topological structure of the multi-region distribution network, wherein the radial topological structure includes a main line, branch nodes, and branch lines.

[0005] Establish the connection relationship and power upstream and downstream relationship of each node in the radial distribution network, and derive and obtain the linearized derivation result of the relationship between the square term of the voltage and the node load power in the radial distribution network.

[0006] According to the radial topological structure, based on the voltage improvement degree, and in combination with the predetermined control node quantity constraint, determine the distribution of energy interconnection nodes.

[0007] According to the linearized derivation result and the distribution of energy interconnection nodes, perform hierarchical scheduling decisions, wherein the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions.

[0008] In a second aspect, the present invention further provides an energy interconnection scheduling system for a multi-region distribution network, wherein the system includes: A radial topological structure determination module for determining the radial topological structure of the multi-region distribution network, wherein the radial topological structure includes a main line, branch nodes, and branch lines.

[0009] A connection relationship and power relationship establishment module, which is used to establish the connection relationship and the upstream and downstream power relationships of each node in the radial distribution network, and derive and obtain the linearized derivation result of the relationship between the square term of the voltage and the node load power in the radial distribution network.

[0010] An energy interconnection node distribution determination module, which is used by a user to determine the energy interconnection node distribution according to the radiation topology structure, based on the voltage improvement degree, in combination with a predetermined control node quantity constraint.

[0011] A hierarchical scheduling decision-making module, which is used to make hierarchical scheduling decisions according to the linearized derivation result and the energy interconnection node distribution, wherein the hierarchical scheduling decision includes an upper-layer decision and a lower-layer decision.

[0012] The present invention discloses an energy interconnection scheduling method and system for a multi-region distribution network, including: determining the radiation topology structure of the multi-region distribution network, which topology structure includes a main line, branch nodes, and branch lines; establishing the connection relationships of each node in the radial distribution network, analyzing the upstream and downstream power relationships of each node, and deriving the linearized relationship between the square term of the voltage and the node load power; determining the distribution of energy interconnection nodes according to the radiation topology structure and the voltage improvement degree, in combination with a preset control node quantity constraint; making hierarchical scheduling decisions based on the linearized derivation result and the energy interconnection node distribution, and the decision-making process includes the collaborative optimization of the upper-layer decision and the lower-layer decision. The energy interconnection scheduling method and system for the multi-region distribution network disclosed by the present invention solve the technical problems of unreasonable access positions of the energy interconnection system and imperfect scheduling methods, realize the balance between global voltage optimization and local economic optimization, and improve the technical effects of the safety, economy, and reliability of the operation of the distribution network. Description of the Drawings

[0013] Figure 1 It is a schematic flowchart of the energy interconnection scheduling method for the multi-region distribution network of the present invention; Figure 2 It is a schematic structural diagram of the energy interconnection scheduling system for the multi-region distribution network of the present invention.

[0014] Description of the reference numerals: The radiation topology structure determination module 11, the connection relationship and power relationship establishment module 12, the energy interconnection node distribution determination module 13, and the hierarchical scheduling decision-making module 14. Detailed Embodiment

[0015] The above technical solutions will be described in detail below in combination with the accompanying drawings of the specification and specific embodiments to better understand the above technical solutions. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited to the example embodiments only used to explain the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all are shown in the drawings. Embodiment 1

[0016] Figure 1 It is a schematic flowchart of the energy interconnection dispatching method for a multi-region distribution network of the present invention. Among them, the method includes: S100: Determine the radial topological structure of the multi-region distribution network, where the radial topological structure includes a main line, branch nodes, and branch lines.

[0017] Specifically, in the distribution network, the radial topological structure refers to a network structure that radiates outward from a central node (usually a substation) through a series of lines and nodes. Each node in the radial topological structure has a clear upstream node and possibly multiple downstream nodes, forming a tree-like network.

[0018] Specifically, the main line is the main line starting from the central node, usually carrying a large current and power; the branch node is the node bifurcated from the main line, and the branch line is the line extending from the branch node to connect more distant users or loads.

[0019] Specifically, by determining the radial topological structure and establishing node connection relationships, the power flow and voltage distribution in the distribution network can be accurately characterized, providing a basis for global voltage optimization.

[0020] In some embodiments, determining the topological structure of the multi-region distribution network includes: Interact with the multi-region distribution network, select a complete line with the head end as the entrance and no other branches at the end as the main line; number the nodes of the main line in sequence from the head end to the end; according to the numbering sequence, sequentially retrieve whether there are bifurcated branches at each node of the main line. If so, regard the corresponding bifurcated branch as a sub-distribution network with the entrance as the corresponding node; traverse the multi-region distribution network and repeat the retrieval and numbering until all node numbering is completed.

[0021] Specifically, node numbers are assigned to each node in the distribution network in a certain order to facilitate subsequent analysis and calculation; a secondary distribution network corresponds to a branch network (branch line) with a certain node (branch node) as the entrance and can be regarded as a subset of the main distribution network.

[0022] Specifically, first, perform an interactive analysis on the distribution network involving multiple regions to understand the connection methods and power flow directions between different regions. Starting from the entrance of the distribution network (usually a substation), select a complete line with the entrance at the head end and no other branches at the tail end as the main line. This line is the main transmission path of the distribution network and undertakes most of the power transmission tasks. Then, number the nodes of the main line in sequence from the head end to the tail end to clarify the order and position of the nodes, facilitating subsequent analysis and calculation. Next, according to the numbering order, sequentially check whether there are bifurcated branches at each node of the main line. If there are bifurcated branches, regard the corresponding bifurcated branch as a secondary distribution network with the corresponding node as the entrance, so as to identify all possible branches for further analysis.

[0023] Furthermore, repeat the above steps for each secondary distribution network until all node numbers are completed, ensuring that all nodes in the entire distribution network are numbered, forming a complete topological structure.

[0024] The above method steps provide a clear structural framework for subsequent analysis and optimization by clarifying the main line, branch nodes, and branch lines; making the connection relationships between nodes and the power flow directions more explicit, facilitating analysis and voltage calculation.

[0025] S200: Establish the connection relationships and power upstream-downstream relationships of each node in the radial distribution network, and derive the linearized derivation result of the relationship between the square term of voltage and the node load power in the radial distribution network.

[0026] Specifically, the node connection relationship refers to the physical connection situation between each node in the distribution network, that is, which nodes are directly connected and which nodes are indirectly connected through other nodes; the power upstream-downstream relationship refers to the power flow direction in the distribution network, that is, the power relationship transmitted from the upstream node to the downstream node. Specifically, linearized derivation is to transform the non-linear voltage-power relationship into a linear relationship through mathematical methods to facilitate calculation and optimization.

[0027] By establishing the node connection relationship and power upstream-downstream relationship, it provides the necessary information for subsequent calculation of voltage improvement degree and optimal dispatching; the linearized derivation result makes the calculation of the voltage-power relationship more efficient, can quickly optimize the operation boundaries of each energy interconnection device, and ensure the stability of the overall network voltage level.

[0028] In some embodiments, establishing the connection relationships and power upstream-downstream relationships of each node in a radial distribution network includes: According to the topological structure, construct a directed graph of the distribution network. In the directed graph, the node set represents all nodes except the head end, and the edge set represents the connection lines between nodes, with the direction pointing from the upstream node to the downstream node; calculate the adjacency matrix representing the direct connection relationships between nodes, and calculate and obtain the reachability matrix representing the indirect connection relationships between nodes based on the adjacency matrix; based on the adjacency matrix and the reachability matrix, determine the connection relationships and power upstream-downstream relationships of each node.

[0029] Specifically, a directed graph is a graph structure in which the edges have directions, representing the relationship of pointing from one node to another; the node set is a set containing all nodes except the head-end node in the distribution network; the edge set represents the set of connection lines between nodes, and each edge has a direction, pointing from the upstream node to the downstream node.

[0030] Specifically, the adjacency matrix is used to represent the direct connection relationships between nodes. If there is a direct connection between node i and node j, the value of the i-th row and j-th column of the adjacency matrix is 1, otherwise it is 0.

[0031] Specifically, the reachability matrix is used to represent the indirect connection relationships between nodes. If node j can be reached from node i through several edges, the value of the i-th row and j-th column of the reachability matrix is 1, otherwise it is 0.

[0032] Specifically, to establish the connection relationships and power upstream-downstream relationships of each node in a radial distribution network, first, according to the determined radial topological structure, construct a directed graph of the distribution network. In the directed graph, the node set represents all nodes except the head end, and the edge set represents the connection lines between nodes, with the direction pointing from the upstream node to the downstream node. The purpose of this step is to represent the topological structure of the distribution network in the form of a graph for subsequent analysis and calculation; then, according to the structure of the directed graph, calculate the adjacency matrix representing the direct connection relationships between nodes. The adjacency matrix is a Boolean matrix, and the elements in it represent whether there is a direct connection between nodes, thereby clarifying the direct connection relationships between nodes and providing a basis for the subsequent calculation of the reachability matrix.

[0033] Further, based on the adjacency matrix, calculate and obtain the reachability matrix representing the indirect connection relationships between nodes. The reachability matrix is also a Boolean matrix, and the elements in it represent whether one node can reach another node through several edges to clarify the indirect connection relationships between nodes and provide a basis for the subsequent analysis of the power upstream-downstream relationships. In particular, the indirect connection relationships represented in the reachability matrix are all one-way relationships, that is, the elements in the lower triangular part of the reachability matrix are 0.

[0034] Specifically, based on the adjacency matrix and the reachability matrix, the connection relationships and the upstream and downstream relationships of power among various nodes can be determined. Among them, the reachability matrix can clarify the upstream nodes and downstream nodes of each node, thereby determining the power flow direction. Through the above steps, necessary information is provided for subsequent calculation of voltage improvement degree and optimal scheduling. By clarifying the connection relationships and power flow directions among nodes, power flow analysis and voltage calculation can be carried out more accurately, providing a basis for optimal scheduling.

[0035] In some embodiments, obtaining the linearized derivation result of the relationship between the square term of voltage and the node load power in a radial distribution network includes: Based on the reachability matrix, define a line impedance matrix; according to the transfer relationship of the square terms of voltage between nodes, combined with the line impedance matrix and the reachability matrix, derive the linearized relationship between the square term of node voltage and the node load power.

[0036] Specifically, the line impedance matrix is a square matrix used to represent the impedance of each line in the distribution network. The value of the i-th row and j-th column of this matrix represents the line impedance from node i to node j; the square term of voltage is used to simplify the calculation because the square value of voltage has a direct relationship with power, which helps to transform the non-linear voltage-power relationship into a linear relationship through mathematical methods for easy calculation and optimization.

[0037] Specifically, to obtain the linearized derivation result of the relationship between the square term of voltage and the node load power in a radial distribution network, first, based on the reachability matrix, define a line impedance matrix, which characterizes the impedance of each line in the distribution network and is the basis for calculating the voltage-power relationship. Then, according to the transfer relationship of the square terms of voltage between nodes, combined with the line impedance matrix and the reachability matrix, derive the linearized relationship between the square term of node voltage and the node load power, transforming the non-linear voltage-power relationship into a linear relationship and simplifying the subsequent calculation and optimization process.

[0038] Optionally, the transfer relationship of the square terms of voltage between nodes is characterized as: ; Wherein, is the square of the voltage of node i, is the square of the voltage of the reference node (such as a power source or a substation), which is usually a constant and used as a benchmark for calculating the voltages of other nodes, and are respectively the resistance and reactance of the transmission line connecting node t to the previous node (such as node t - 1), and are respectively the active power and reactive power loads of node t. Among them, Node i-up is the set of upstream nodes of node i, that is, Nodei-up Any one of the nodes can reach node i, and t is any node in Node i-up in it.

[0039] In other words, there is a relationship: ; Therefore, the reachability matrix M of the transposed matrix M T can be used to represent this relationship. The non-zero elements in the i-th row of the transposed matrix of the reachability matrix represent the set of upstream nodes of node i. On this basis, the node line impedance matrix is defined. Considering the multiplication principle with the line power flow matrix, this matrix is an N-order diagonal square matrix: ; ; where R is the resistive matrix in the line impedance matrix; X is the reactive matrix in the line impedance matrix.

[0040] Furthermore, based on the resistive matrix R and reactive matrix X in the line impedance matrix, the reachability matrix M and the transposed matrix M T , the transfer relationship of the square term of the voltage between nodes is rewritten to obtain the matrix form: ; where represents the square term of the voltage; represents the square term of the voltage of the inlet node; P represents the active part of the power flow; Q represents the reactive part of the power flow; P L represents the active part of the node load; Q L represents the reactive part of the node load.

[0041] Through the transfer relationship of the square term of the voltage between nodes in the above matrix form, the square terms of the voltages of each node in the radial distribution network can be directly obtained by matrix calculation, and then the voltage values of each node can be calculated, which simplifies the original recursive calculation process.

[0042] In the whole scheme, obtaining the linearization relationship is the key step, which provides the necessary mathematical tool for the subsequent calculation of the voltage improvement degree and the optimal scheduling. Through the linearization relationship, the voltage calculation and optimization can be carried out more efficiently, improving the calculation speed and accuracy.

[0043] S300: According to the radiation topology structure, based on the voltage improvement degree, combined with the predetermined control node quantity constraint, determine the distribution of energy interconnection nodes.

[0044] Specifically, the voltage improvement degree is used to measure the degree of voltage improvement of all nodes in the whole network after installing an energy interconnection device with a unit capacity at a certain node. This index comprehensively considers the influence of active and reactive power and evaluates the effectiveness of configuring the energy interconnection device at the node; the predetermined control node quantity constraint is the upper limit of the number of nodes where the energy interconnection device needs to be installed, which is preset according to actual requirements and system design.

[0045] Specifically, the access planning method based on the voltage improvement degree, combined with the predetermined control node quantity constraint, can reasonably determine the access location of the energy interconnection device, avoid the concentrated accumulation of access points, realize the balanced distribution of the energy interconnection device in the distribution network, improve the voltage level of the whole network, and enhance the overall performance of the distribution network.

[0046] In some embodiments, according to the radial topology structure, based on the voltage improvement degree, combined with the predetermined control node quantity constraint, to determine the energy interconnection node distribution, including: Calculate the voltage improvement degree index of each node; sort the nodes according to the voltage improvement degree index to determine the priority sequence of access points; select access points from the priority sequence according to the predetermined control node quantity constraint to achieve the balanced distribution of the energy interconnection nodes in the regional distribution network.

[0047] Specifically, the priority sequence is a sequence formed by sorting all nodes according to the voltage improvement degree index and is used to determine the priority of access points.

[0048] Specifically, according to the radial topology structure, based on the voltage improvement degree, combined with the predetermined control node quantity constraint, to determine the energy interconnection node distribution. First, for each node in the distribution network, calculate its voltage improvement degree index, which reflects the degree of voltage improvement of all nodes in the whole network after installing an energy interconnection device with a unit capacity at this node. The higher the voltage improvement degree index, the higher the benefit of deploying the energy interconnection device at the corresponding node; then, sort all nodes according to the calculated voltage improvement degree index to form a priority sequence, and the nodes with higher voltage improvement degree have higher priority and are ranked at the front of the sequence; finally, select access points from the priority sequence according to the predetermined control node quantity constraint.

[0049] Specifically, in order to avoid the concentrated accumulation of access points, the step-by-step elimination method can be adopted, that is, after selecting an access point, a certain number of its adjacent nodes are removed from the candidate list, and then the next access point is selected, and this process is repeated until all access points are determined.

[0050] The function of the above steps is to reasonably determine the access location of the energy interconnection device, avoid the concentrated accumulation of access points, realize the balanced distribution of the energy interconnection device in the distribution network, thereby improving the voltage level of the whole network and enhancing the overall performance of the distribution network.

[0051] In some implementations, the voltage improvement degree index of each node is calculated, where the voltage improvement degree is expressed as: ; where represents the voltage improvement degree of all nodes after installing an energy interconnection device with a unit capacity at node ; is the power factor; represents the square term of the voltage at node ; represents the active power part of the load at any node ; represents the reactive power part of the load at node ;

[0052] Specifically, the energy interconnection device of the regional distribution network can adjust its own operating state and transmit active / reactive power to the power grid to improve the voltage level of the distribution network and participate in voltage governance. The improvement degree is reflected in both the active and reactive power parts.

[0053] Specifically, for each node i, calculate the partial derivatives of its voltage square term with respect to the active and reactive power of all nodes j and (which can be considered as the sensitivity of the voltage square term to the node power change), and substitute the calculated partial derivatives into the voltage improvement degree formula to calculate the voltage improvement degree index of each node.

[0054] Optionally, the power factor satisfies , and the power factor when the active power upper limit of the energy interconnection device of the regional distribution network is taken. Since the power flow from the power grid to the energy interconnection device of the regional distribution network is defined as the positive direction in the distribution network, a negative sign is added before the sensitivity parameters and .

[0055] Specifically, the beneficial effects of calculating the voltage improvement degree index of each node include: through the voltage improvement degree index, the voltage improvement potential of each node can be more accurately evaluated, providing a scientific basis for the selection of access points. The calculation of the voltage improvement degree index makes the selection of access points more reasonable, avoids the concentrated accumulation of access points, and realizes the balanced distribution of the energy interconnection device of the regional distribution network in the distribution network. The calculation of the voltage improvement degree index provides a basis for optimal scheduling, enabling more accurate optimal scheduling, improving the efficiency and accuracy of scheduling, and thus improving the overall performance of the distribution network.

[0056] S400: Based on the linearization derivation result and the distribution of the energy interconnection nodes, hierarchical scheduling decisions are made, where the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions.

[0057] Specifically, the hierarchical scheduling decisions combine global voltage optimization and local economic optimization. Among them, the upper-layer optimization determines the operation boundaries of each energy interconnection device, providing constraint conditions for the lower-layer optimization; while the lower-layer optimization further explores economic indicators under these constraint conditions by using the operation optimization strategy of the energy interconnection device of the single-area distribution network on the user side to achieve local economic optimization.

[0058] Specifically, the upper-layer decisions determine the upper and lower boundaries of the active power operation of each energy interconnection device of the regional distribution network at each moment during the scheduling period according to the linearization derivation result and the distribution of the energy interconnection nodes. With the goal of obtaining the maximum adjustable range of the active power of each energy interconnection device of the regional distribution network, optimization is solved. Ensure that when all energy interconnection devices of the regional distribution network operate at the upper or lower boundary of the active power, the voltage of each node in the distribution network is within the allowable range to prevent voltage dips or overlimits.

[0059] Specifically, the lower-layer decisions are based on the upper-layer decision results, and each energy interconnection device of the regional distribution network performs local optimal scheduling respectively. With the goal of energy utilization economy, based on the load prediction results and photovoltaic prediction results of each time period during the known scheduling period, the power flow of each port of the energy interconnection device of the regional distribution network is optimized and solved.

[0060] In some embodiments, based on the linearization derivation result and the distribution of the energy interconnection nodes, hierarchical scheduling decisions are made, where the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions, including: Based on the historical load power data of each node in the multi-region distribution network, determine the upper and lower boundaries of the active power operation of each energy interconnection node of the regional distribution network at each moment during the scheduling period; according to the upper and lower boundaries of the operation, combined with the maximum charge and discharge strategy of the energy storage device and the typical output strategy of the charging pile, define the scheduling constraint set; with the goal of maximizing the adjustable range of the active power of each energy interconnection node, combined with the scheduling constraint set, the linearization derivation result and the distribution of the energy interconnection nodes, perform upper-layer decision optimization and solution; add the upper-layer decision optimization and solution result to the constraint condition set, and with the goal of optimal operation economy, use the port power flow of each energy interconnection node as the decision variable to perform lower-layer decision optimization and solution, where the constraint condition set at least includes energy storage constraints, photovoltaic constraints, electric vehicle constraints, power balance constraints and capacity constraints; output the upper-layer decision optimization and solution result and the lower-layer decision optimization and solution result as the hierarchical scheduling decision result.

[0061] Specifically, historical load power data refers to the load power records of each node over a past period of time, which is used to predict and plan future load demands; the upper and lower boundaries of active power operation are the maximum and minimum values of the active power allowed by the energy interconnection devices of each regional distribution network during the scheduling period; the adjustable range of active power refers to the range of active power that the energy interconnection devices of each regional distribution network can adjust during the scheduling period.

[0062] Specifically, the maximum charge-discharge power of the energy storage device refers to the maximum charge and discharge power that the energy storage device can perform per unit time; the typical output power of the charging pile is the typical output power (such as the average output power) when the charging pile is working normally; the port power flow refers to the power flow between each energy interconnection device and the power grid, including active and reactive power.

[0063] Specifically, according to the linearization derivation results and the distribution of energy interconnection nodes, hierarchical scheduling decisions are made. First, the operating boundaries of active power are determined: based on the historical load power data of each node in the multi-regional distribution network, the load demands at each moment during the scheduling period are predicted, and according to the prediction results, the upper and lower boundaries of the active power operation of each energy interconnection node in the regional distribution network at each moment during the scheduling period are determined; then, a scheduling constraint set is defined: according to the upper and lower operating boundaries, combined with the maximum charge-discharge power of the energy storage device and the typical output power of the charging pile, a scheduling constraint set is defined; next, the upper-layer decision optimization solution is carried out: combined with the optimization algorithm, with the goal of maximizing the adjustable range of active power of each energy interconnection node, combined with the scheduling constraint set, the linearization derivation results and the distribution of energy interconnection nodes, the upper-layer decision optimization solution is carried out, and the upper-layer decision optimization solution results obtained include the operating boundaries of the active power of each regional distribution network energy interconnection system at each moment during the scheduling period.

[0064] Furthermore, the lower-layer decision optimization solution is carried out: the upper-layer decision optimization solution results are added to the constraint condition set, and with the goal of optimizing the operating economy, aiming to minimize the operating costs, including energy costs, equipment operating costs, etc., with the port power flow of each energy interconnection node as the decision variable, the lower-layer decision optimization solution is carried out through mathematical optimization methods (such as linear programming, mixed integer programming, etc.) to obtain the optimal port power flow to achieve the optimal operating economy. Among them, the constraint condition set for the lower-layer decision optimization solution includes energy storage constraints, photovoltaic constraints, electric vehicle constraints, power balance constraints, capacity constraints, etc., and the lower-layer decision optimization solution results obtained include the optimal power flow of each energy interconnection system at each moment during the scheduling period.

[0065] Exemplarily, the energy storage constraint refers to the charge and discharge power and capacity limits of the energy storage device. The photovoltaic constraint refers to the output power limit of the photovoltaic power generation equipment. The electric vehicle constraint refers to the charge and discharge power limits of electric vehicles. The power balance constraint is used to ensure the balance between power supply and demand in the system. The capacity constraint refers to the capacity limits of various devices, such as transformers, lines, etc.

[0066] Furthermore, output the upper-layer decision optimization solution result and the lower-layer decision optimization solution result as the final result of the hierarchical scheduling decision. The above-mentioned hierarchical scheduling decision combines global and local optimization, while reducing the optimization complexity, realizes the coordination of global voltage optimization and local economic optimization, improves the overall performance of the distribution network, and helps to improve the operation efficiency and economic benefits of the distribution network.

[0067] In summary, the energy interconnection scheduling method for a multi-region distribution network provided by the present invention has the following technical effects: By determining the radial topological structure of the multi-region distribution network, which includes main lines, branch nodes, and branch lines; establishing the connection relationships of each node in the radial distribution network and analyzing the upstream and downstream power relationships of each node, a linearized relationship between the square term of voltage and the node load power is deduced; according to the radial topological structure and voltage improvement degree, combined with the preset control node quantity constraint, determine the distribution of energy interconnection nodes; based on the linearized derivation result and the distribution of energy interconnection nodes, perform hierarchical scheduling decision-making, and this decision-making process includes the collaborative optimization of the upper-layer decision and the lower-layer decision, so as to achieve the balance of global voltage optimization and local economic optimization, and improve the safety, economy, and reliability of the distribution network operation. Embodiment 2

[0068] Figure 2 It is a schematic structural diagram of the energy interconnection scheduling system for a multi-region distribution network of the present invention. For example, Figure 1 The flow schematic diagram of the energy interconnection scheduling method for the multi-region distribution network of the present invention can be implemented through a structure as shown in Figure 2 shown.

[0069] Based on the same concept as the energy interconnection scheduling method for the multi-region distribution network in the above embodiment, the energy interconnection scheduling system for a multi-region distribution network provided by the present invention further includes: A radial topological structure determination module 11, configured to determine the radial topological structure of the multi-region distribution network, where the radial topological structure includes main lines, branch nodes, and branch lines.

[0070] A connection relationship and power relationship establishment module 12, configured to establish the connection relationships and upstream and downstream power relationships of each node in the radial distribution network, and deduce and obtain the linearized derivation result of the relationship between the square term of voltage and the node load power in the radial distribution network.

[0071] The energy interconnection node distribution determination module 13 is configured to determine the energy interconnection node distribution according to the radiation topology structure, based on the voltage improvement degree, in combination with a predetermined control node quantity constraint.

[0072] The hierarchical scheduling decision-making module 14 is configured to perform hierarchical scheduling decision-making according to the linearization derivation result and the energy interconnection node distribution, where the hierarchical scheduling decision-making includes upper-layer decision-making and lower-layer decision-making.

[0073] In some embodiments, the radiation topology structure determination module 11 includes: The backbone line selection unit is configured to interact with a multi-region distribution network and select a complete line with the head end as the entrance and no other branches at the tail end as the backbone line.

[0074] The node numbering unit is configured to number the nodes of the backbone line in sequence from the head end to the tail end.

[0075] The sub-distribution network retrieval unit is configured to sequentially retrieve whether there are bifurcated branches at each node of the backbone line according to the numbering order. If there are, the corresponding bifurcated branch is regarded as a sub-distribution network with the corresponding node as the entrance.

[0076] The node numbering completion unit is configured to traverse the multi-region distribution network for repeated retrieval and numbering until all nodes are numbered.

[0077] In some embodiments, the connection relationship and power relationship establishment module 12 includes: The directed graph construction unit is configured to construct a directed graph of the distribution network according to the topology structure. In the directed graph, the node set represents all nodes except the head end, and the edge set represents the connection lines between nodes, and the direction points from the upstream node to the downstream node.

[0078] The adjacency matrix and reachability matrix calculation unit is configured to calculate an adjacency matrix representing the direct connection relationship between nodes, and calculate and obtain a reachability matrix representing the indirect connection relationship between nodes according to the adjacency matrix.

[0079] The connection relationship and power relationship determination unit is configured to determine the connection relationship and power upstream and downstream relationship of each node based on the adjacency matrix and the reachability matrix.

[0080] In some embodiments, the connection relationship and power relationship establishment module 12 further includes: The line impedance matrix definition unit is configured to define a line impedance matrix based on the reachability matrix.

[0081] A linearization relationship derivation unit, configured to derive and obtain a linearization relationship between the square term of the node voltage and the node load power according to the transfer relationship of the square terms of the voltages between nodes, in combination with the line impedance matrix and the reachability matrix.

[0082] In some embodiments, the energy interconnection node distribution determination module 13 includes: A voltage improvement degree index calculation unit, configured to calculate the voltage improvement degree index of each node.

[0083] An access point priority sequence determination unit, configured to sort the nodes according to the voltage improvement degree index to determine the priority sequence of the access points.

[0084] An energy interconnection node distribution unit, configured to select access points from the priority sequence according to a predetermined control node quantity constraint to perform an even distribution of the energy interconnection nodes in the regional distribution network.

[0085] In some implementation manners, the voltage improvement degree in the energy interconnection node distribution determination module 13 is expressed as: ; Wherein, characterizes the voltage improvement degree of all nodes after installing an energy interconnection device with a unit capacity at node ; is the power factor; characterizes the square term of the voltage at any node ; characterizes the active power part of the load at node ; characterizes the reactive power part of the load at node ;

[0086] In some embodiments, the hierarchical scheduling decision-making module 14 includes: An active power operation boundary determination unit, configured to determine the upper and lower boundaries of the active power operation of the energy interconnection nodes in each regional distribution network at each moment within a scheduling period based on the historical load power data of each node in the multi-regional distribution network.

[0087] A scheduling constraint set definition unit, configured to define a scheduling constraint set according to the upper and lower operation boundaries, in combination with the maximum charge and discharge strategy of the energy storage device and the typical output strategy of the charging pile.

[0088] An upper-layer decision optimization solving unit, configured to perform upper-layer decision optimization solving with the goal of maximizing the adjustable range of the active power of each energy interconnection node, in combination with the scheduling constraint set, the linearization derivation result, and the energy interconnection node distribution.

[0089] The lower-layer decision optimization and solution unit is used to add the upper-layer decision optimization and solution results to the constraint set, and perform lower-layer decision optimization and solution with the optimal operating economy as the optimization goal and the port power flow of each energy interconnection node as the decision variable. Among them, the constraint set at least includes energy storage constraints, photovoltaic constraints, electric vehicle constraints, power balance constraints, and capacity constraints.

[0090] The hierarchical scheduling decision result output unit is used to output the upper-layer decision optimization and solution results and the lower-layer decision optimization and solution results as the hierarchical scheduling decision results.

[0091] It should be understood that the embodiments mentioned in this specification focus on their differences from other embodiments. The specific embodiments in the foregoing Embodiment 1 are equally applicable to the energy interconnection scheduling system of the multi-region distribution network described in Embodiment 2. For the sake of brevity of the specification, no further elaboration is made here.

[0092] It should be understood that the disclosed embodiments of the present invention and the above descriptions can enable those skilled in the art to implement the present invention using the present invention. At the same time, the present invention is not limited to the above-mentioned part of the embodiments. It should be understood that those of ordinary skill in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. Energy interconnection scheduling method for multi - area distribution network, characterized in that The method includes: Determine the radial topology of the multi-region distribution network, where the radial topology includes a main line, branch nodes, and branch lines; Establish the connection relationship and power upstream and downstream relationship of each node in the radial distribution network, and derive the linearized derivation result of the relationship between the square term of the voltage and the node load power in the radial distribution network; According to the radial topology, based on the voltage improvement degree, combined with the predetermined control node quantity constraint, determine the distribution of energy interconnection nodes; According to the linearized derivation result and the distribution of energy interconnection nodes, perform hierarchical scheduling decisions, where the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions.

2. The energy interconnection scheduling method for a multi-region distribution network according to claim 1, characterized in that Determine the topology of the multi-region distribution network, including: Interact with the multi-region distribution network, and select a complete line with the head end as the entrance and no other branches at the end as the main line; Number the nodes of the main line in sequence from the head end to the end; According to the numbering sequence, sequentially retrieve whether there are bifurcated branches at each node of the main line. If so, regard the corresponding bifurcated branch as a sub-distribution network with the corresponding node as the entrance; Traverse the multi-region distribution network and repeat the retrieval and numbering until all node numbering is completed.

3. The energy interconnection scheduling method for a multi-region distribution network according to claim 2, characterized in that Establish the connection relationship and power upstream and downstream relationship of each node in the radial distribution network, including: According to the topology, construct a directed graph of the distribution network. The node set in the directed graph represents all nodes except the head end, and the edge set represents the connection lines between nodes, and the direction points from the upstream node to the downstream node; Calculate the adjacency matrix representing the direct connection relationship between nodes, and calculate the reachability matrix representing the indirect connection relationship between nodes according to the adjacency matrix; Based on the adjacency matrix and the reachability matrix, determine the connection relationship and power upstream and downstream relationship of each node.

4. The energy interconnection scheduling method for a multi-region distribution network according to claim 3, characterized in that Obtain the linearized derivation result of the relationship between the square term of the voltage and the node load power in the radial distribution network, including: Based on the reachability matrix, define the line impedance matrix; According to the transfer relationship of the square term of the voltage between nodes, combined with the line impedance matrix and the reachability matrix, derive the linearized relationship between the square term of the node voltage and the node load power.

5. The energy interconnection scheduling method for a multi-region distribution network according to claim 4, characterized in that According to the radial topology, based on the voltage improvement degree, combined with the predetermined control node quantity constraint, determine the distribution of energy interconnection nodes, including: Calculate the voltage improvement degree index of each node; Sort the nodes according to the voltage improvement degree index to determine the priority sequence of access points; According to the predetermined control node quantity constraint, select access points from the priority sequence to perform the balanced distribution of the energy interconnection nodes in the regional distribution network.

6. The energy interconnection scheduling method for a multi-region distribution network according to claim 5, characterized in that Calculate the voltage improvement degree index of each node, where the voltage improvement degree is expressed as: ； Among them, Characterize the node After installing the energy interconnection device with a unit capacity at the location, the voltage improvement degree of all nodes; Is the power factor; Characterize the node The square term of the voltage at the location; Characterize any node The active part of the load at the location; Characterize the node The reactive part of the load at the location.

7. The energy interconnection scheduling method for a multi-region distribution network according to claim 5, characterized in that, According to the linearized derivation result and the distribution of energy interconnection nodes, perform hierarchical scheduling decisions, where the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions, including: Based on the historical load power data of each node in the multi-region distribution network, determine the upper and lower boundaries of the active power operation at each moment during the scheduling period of the energy interconnection nodes in each regional distribution network; Define a scheduling constraint set according to the upper and lower operating boundaries, combined with the maximum charge-discharge strategy of the energy storage device and the typical output strategy of the charging pile; Aiming at the maximum adjustable range of the active power of each energy interconnection node, combined with the scheduling constraint set, the linearization derivation result and the energy interconnection node distribution, perform upper-layer decision optimization and solution; Add the upper-layer decision optimization and solution result to the constraint condition set, and with the optimal operation economy as the optimization goal and the port power flow of each energy interconnection node as the decision variable, perform lower-layer decision optimization and solution, where the constraint condition set at least includes energy storage constraints, photovoltaic constraints, electric vehicle constraints, power balance constraints and capacity constraints; Output the upper-layer decision optimization and solution result and the lower-layer decision optimization and solution result as the hierarchical scheduling decision result.

8. Energy interconnection dispatching system for multi-region distribution network, characterized in that The system is used to execute the energy interconnection scheduling method of the multi-region distribution network according to any one of claims 1-7. The system includes: A radiation topology determination module for determining the radiation topology of the multi-region distribution network, where the radiation topology includes a main line, a branch node and a branch line; A connection relationship and power relationship establishment module for establishing the connection relationship and power upstream and downstream relationship of each node in the radial distribution network, and deriving the linearization derivation result of the relationship between the square of the voltage and the node load power in the radial distribution network; An energy interconnection node distribution determination module for determining the energy interconnection node distribution according to the radiation topology, based on the voltage improvement degree, combined with the predetermined control node quantity constraint; A hierarchical scheduling decision module for performing hierarchical scheduling decisions according to the linearization derivation result and the energy interconnection node distribution, where the hierarchical scheduling decisions include upper-layer decisions and lower-layer decisions.

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