Resource regulation capability evaluation method and system of power distribution network

Abstract

The invention discloses a resource adjustment capability evaluation method and system for a power distribution network, and the method comprises the steps: constructing a power distribution network-bus branch topological graph according to a physical structure of the power distribution network, and carrying out the parallel division of the power distribution network-bus branch topological graph, and obtaining a plurality of electrical islands; traversing nodes in each electrical island, and dividing the nodes of the electrical island into a first node set or a second node set of the electrical island; based on a preset line power flow constraint, the first node set and the second node set, constructing a resource adjustment aggregation model of each electrical island; and integrating the resource adjustment aggregation model to obtain a flexible resource scheduling model of the power distribution network so as to evaluate the resource adjustment capability of the power distribution network. According to the method, the resource adjustment capability of the nodes in the power distribution network is efficiently predicted, so that the resource adjustment capability of the power distribution network is accurately evaluated.

Description

Technical Field

[0001] The present application belongs to the field of power system operation and control technology, and specifically relates to a method and system for evaluating the resource regulation capability of a distribution network. Background Art

[0002] In large-scale power systems, with the access of massive distributed entities, the two-way flow of active and reactive power between the main grid and the distribution grid increases. We can no longer consider only the one-way flow of resources, and the impact of the distribution grid on the main grid becomes difficult to ignore. Therefore, it is necessary to accurately predict the mutual influence of the adjustable resource flow between the distribution grid and the main grid by building a resource aggregation model, so as to accurately evaluate the resource regulation capacity of the distribution network.

[0003] Existing resource aggregation models are generally considered and constructed from the distribution side of the power system. However, the data on the distribution side is complex and the calculation time required is too long. In addition, the constructed models are generally driven by data structures and it is difficult to describe the changes in the power system under different working conditions. Therefore, there is also the problem of poor model portability. Summary of the invention

[0004] The present application proposes a method and system for evaluating the resource regulation capability of a distribution network, which achieves accurate evaluation of the resource regulation capability of the distribution network by efficiently predicting the resource regulation capability of nodes in the distribution network.

[0005] A first aspect of the present application provides a method for evaluating resource regulation capability of a distribution network, the method comprising:

[0006] According to the physical structure of the distribution network, construct the distribution network-bus branch topology diagram;

[0007] The distribution network-busbar branch topology diagram is divided in parallel to obtain a plurality of electrical islands;

[0008] Traversing the nodes in each electrical island, and dividing the nodes of the electrical island into a first node set or a second node set of the electrical island according to the node structure of each electrical island;

[0009] Based on the preset line flow constraints, the first node set and the second node set, construct a resource regulation aggregation model for each electrical island;

[0010] The resource regulation aggregation model is integrated to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

[0011] The above scheme first divides the topological structure of the distribution network into multiple electrical islands, and then separately models them in parallel with the electrical islands, thereby improving the calculation rate by reducing the amount of calculation. For each electrical island, nodes are traversed and the nodes are divided into the first node set or the second node set to realize the classification of different types of nodes; then based on these node sets, on the basis of line flow constraints, considering the mutual influence between nodes, a corresponding resource regulation aggregation model is constructed for each electrical island to describe the resource allocation capability of each electrical island. Moreover, because different electrical islands are modeled separately and different working conditions are considered through line flow constraints, the constructed resource regulation aggregation model has high transferability and is suitable for different working conditions. Finally, the models of all electrical islands are integrated to obtain a distribution network flexible resource scheduling model for predicting the entire distribution network, so as to accurately evaluate the resource regulation capability of the distribution network.

[0012] In a possible implementation method of the first aspect, the distribution network-bus branch topology diagram is divided in parallel to obtain a plurality of electrical islands, specifically:

[0013] Retrieving low-voltage side nodes and load nodes in the distribution network-bus branch topology diagram;

[0014] The busbar in the distribution network-busbar branch topology diagram is taken as the root node, and the low-voltage side nodes and load nodes corresponding to the busbar are taken as leaf nodes to construct a plurality of electrical islands.

[0015] The above scheme is based on a preset distribution network topology diagram, which divides the distribution network-bus branch topology diagram into several electrical islands that are connected in themselves but independent of each other, so as to facilitate the subsequent parallel and independent calculation of each electrical island, greatly saving the calculation complexity and improving the data calculation efficiency.

[0016] In a possible implementation method of the first aspect, nodes in each electrical island are traversed, and the nodes of the electrical island are divided into a first node set or a second node set of the electrical island according to the node structure of each electrical island, specifically:

[0017] By traversing the nodes of each electrical island, the ring structure in each electrical island is marked;

[0018] The nodes belonging to the ring structure are divided into a first node set of the corresponding electrical island, and the nodes not belonging to the ring structure are divided into a second node set of the corresponding electrical island.

[0019] The above scheme traverses the nodes in each electrical island and marks all the ring structures by finding the nodes that form the ring structure in the electrical island. Because the nodes in the ring structure may communicate with other nodes at the same level or affect the resource adjustment capabilities of multiple parent nodes, it is necessary to divide these ring structure nodes that can have a two-way impact on other nodes into the first node set separately to provide data support for subsequent separate optimization processing.

[0020] In a possible implementation method of the first aspect, the nodes of each electrical island are traversed to mark the ring structure in each electrical island, specifically:

[0021] Determine the first-order neighbor node of the root node of the electrical island, and traverse downward from the first-order neighbor node;

[0022] If the first node currently traversed meets the preset ring construction condition, connectivity analysis is performed on the electrical island according to the first node, and the ring structure corresponding to the first node is marked;

[0023] The traversal is stopped after all nodes in the electrical island are traversed.

[0024] In a possible implementation method of the first aspect, the ring construction condition is specifically:

[0025] If the first node has two parent nodes or there is a node at the same layer that is a first-order neighbor of the first node, it means that the first node meets the ring construction condition.

[0026] In a possible implementation method of the first aspect, a resource regulation aggregation model of each electrical island is constructed based on a preset line flow constraint, the first node set, and the second node set, specifically:

[0027] Calculating the resource adjustment capability of the second node set by an algebraic summation method;

[0028] Based on the line power flow constraint, optimizing the upward resource regulation capacity and the downward resource regulation capacity of the nodes in the first node set to calculate the resource regulation capability of the first node set;

[0029] A resource regulation aggregation model of each electrical island is generated according to the resource regulation capabilities of the second node set and the first node set in each electrical island.

[0030] In the above scheme, the second node set with only one-way influence on the parent node is algebraically summed to obtain the resource adjustment capacity of the second node set; then the first node set with two-way influence on the parent node or ancestor node is analyzed for influencing factors based on the line flow constraints to maximize the prediction of the resource adjustment capacity of the first node set. Finally, based on the obtained data, a corresponding resource adjustment aggregation model is generated for the resource adjustment capacity of each electrical island to achieve optimal prediction of the electrical island. In addition, the line flow constraints provide a background for the change of working conditions for calculating the resource adjustment capacity, which improves the portability of the resource adjustment aggregation model.

[0031] In a possible implementation method of the first aspect, based on the line flow constraint, optimizing the upward resource adjustment capacity and the downward resource adjustment capacity of the nodes in the first node set to calculate the resource adjustment capability of the first node set is specifically as follows:

[0032] According to the sensitivity of each node in the first node set to the associated line and the power flow constraint corresponding to the associated line, constraining the upward resource regulation capacity and the downward resource regulation capacity of each node in the first node set;

[0033] The resource adjustment capacity of the first node set is calculated based on the upward resource adjustment capacity and the downward resource adjustment capacity with the goal of maximizing the total resource adjustment capacity.

[0034] In a possible implementation method of the first aspect, the resource adjustment capability of the first node set is specifically:

[0035] The resource adjustment capability is specifically calculated as follows:

[0036]

[0037] In the formula, The first node set S I Upward resource adjustment capability, The first node set S I The downward resource adjustment capability, P i u is the upward resource adjustment capacity of node i, P i d is the downward resource adjustment capacity of node i, SI is the first node set, k is the root node of the electrical island to which node i belongs, P i u is the lower limit of the upward resource adjustment capacity of node i, is the upper limit of the upward resource adjustment capacity of node i, Ng is the number of nodes in the first node set, Nl is the number of lines, is the sensitivity of each node to line j, P l,j is the lower limit of the line power flow constraint, is the upper limit of the line power flow constraint, is the upward resource adjustment capacity of node i, P i d is the lower limit of the downward resource adjustment capacity of node i, is the upper limit of the downward resource adjustment capacity of node i, The downward resource adjustment capacity of node i.

[0038] A second aspect of the present application provides a resource regulation capability evaluation system for a distribution network, the system comprising: a physical topology construction module, a graph model partitioning module, a node partitioning module, an aggregation model construction module and a resource regulation capability evaluation module;

[0039] Wherein, the physical topology construction module is used to construct a distribution network-bus branch topology diagram according to the physical structure of the distribution network;

[0040] The graph model division module is used to perform parallel division on a preset electrical graph model based on a preset distribution network-bus branch topology graph to obtain a plurality of electrical islands;

[0041] The node division module is used to traverse the nodes in each electrical island, and divide the nodes of the electrical island into the first node set or the second node set of the electrical island according to the node structure of each electrical island;

[0042] The aggregation model building module is used to build a resource regulation aggregation model of each electrical island based on the preset line flow constraints, the first node set and the second node set;

[0043] The resource regulation capability evaluation module is used to integrate the resource regulation aggregation model to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

[0044] A fourth aspect of the present application provides a storage medium, which stores computer-readable program code. When the computer-readable program code is executed, the steps of a method for evaluating the resource regulation capability of a distribution network described in any one of the embodiments of the present application are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 It is a specific flow chart of a method for evaluating resource regulation capability of a distribution network provided in a certain embodiment of the present application;

[0047] Figure 2 It is a ring structure diagram of a method for evaluating resource regulation capability of a distribution network provided in a certain embodiment of the present application;

[0048] Figure 3 It is a non-cyclic structure diagram of a method for evaluating resource regulation capability of a distribution network provided in a certain embodiment of the present application;

[0049] Figure 4 A structural diagram of a resource regulation capability evaluation system for a distribution network is provided in accordance with a certain embodiment of the present application. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] It should be understood that the step numbers used in this article are only for the convenience of description and are not intended to limit the order in which the steps are executed.

[0052] First embodiment

[0053] In the process of evaluating the resource regulation capability of a general distribution network, it is only necessary to aggregate the power, adjustable capacity and other information of each subnet for analysis. However, as more and more distributed entities are connected to the distribution network, the active and reactive bidirectional flows between the distribution network and the main network increase. It is difficult to accurately reflect the mutual influence between the distribution networks by relying solely on a simple aggregation analysis method, and there is a problem of not being applicable to a variety of working conditions. If the aggregated data on the distribution network side is directly optimized to calculate the up- and down-regulation resource capabilities of the subnet, the calculation time will be too long due to the large amount of data that needs to be calculated. Therefore, it is worth studying how to achieve accurate evaluation of the resource regulation capability of the distribution network while improving data calculation efficiency.

[0054] like Figure 1 As shown, Figure 1 A specific flow chart of a method for evaluating the resource regulation capability of a distribution network provided in an embodiment of the present application. The method for evaluating the resource regulation capability of a distribution network in this embodiment includes steps S1 to S5, which are described in detail as follows:

[0055] Step S1, constructing a distribution network-bus branch topology diagram according to the physical structure of the distribution network.

[0056] In the embodiment of the present application, data related to the physical structure of the distribution network, such as device data and line data, are first obtained. Based on these data, a distribution network-bus branch topology diagram is constructed with single-terminal devices as nodes and double-terminal or multi-terminal devices as edges.

[0057] Among them, single-terminal devices include generators, electric vehicles, reactive power compensation devices, loads and energy storage, etc. Double / multi-terminal devices include lines and transformers, etc.

[0058] As an improvement of the above solution, the nodes in the distribution network-bus branch topology diagram need to include the following attributes: adjustable resource type, resource ID, upward resource adjustment capability, downward resource adjustment capability, etc.

[0059] Step S2, dividing the distribution network-bus branch topology diagram in parallel to obtain a plurality of electrical islands.

[0060] In the embodiment of the present application, the root node in the distribution network-bus branch topology diagram is first found, that is, the node for which the aggregation model needs to be constructed. Because in the new distribution network, there are a large number of aggregates with resource regulation capabilities, and their resource regulation capabilities are jointly determined by different resources in the aggregate, and the aggregate can participate in power grid regulation or market transactions as a whole, it is necessary to first construct the corresponding resource regulation aggregation model in parallel with the aggregate as a unit in the embodiment of the present application, and then use these models to evaluate the resource regulation capability of the distribution network as a whole, so as to realize the conversion of ultra-large-scale data calculations into multiple small-scale data calculations.

[0061] Then, starting from the root node, a connectivity analysis is performed on the distribution network-bus branch topology diagram. Specifically, the low-voltage side nodes are searched along the edge of the root node until the load node is reached, indicating that there is no way to go, and the connectivity analysis is completed.

[0062] Then, the root node is used as the busbar, and the low-voltage side nodes and load nodes found from the root node are used as leaf nodes to construct several electrical islands, where each root node corresponds to an electrical island.

[0063] Optionally, the embodiment of the present application uses a 110kV or 220kV bus in the distribution network-bus branch topology diagram as a root node, and uses lower voltage level devices connected to such a bus as leaf nodes.

[0064] In addition, the embodiment of the present application does not limit the number of electrical islands, and uses a calculation engine in a preset database containing distribution network hardware resources to achieve automatic division of electrical islands.

[0065] Step S3, traversing the nodes in each electrical island, and dividing the nodes of the electrical island into the first node set or the second node set of the electrical island according to the node structure of each electrical island.

[0066] In the embodiment of the present application, the nodes of an electrical island are traversed, the ring structure in the electrical island is found and marked, and then the nodes in the electrical island are divided into the first node set or the second node set according to the marked ring structure. Taking a certain electrical island as an example, the electrical island is called electrical island A, and the specific process of dividing the nodes of electrical island A is as follows:

[0067] (1) First, mark the root node of electrical island A as node 0, determine the first-order neighbor node of node 0, and mark the first-order neighbor node as 1(x); where 1 in 1(x) indicates that it is a first-order neighbor of node 0, and the x in the brackets indicates the node number of the same level;

[0068] (2) Starting from the first-order neighbor node, traverse in parallel to find the first-order neighbor node of each 1(x), that is, the second-order neighbor node of the root node, and mark the second-order neighbor node as 2(x)(y); wherein,

[0069] The y in 2(x)(y) represents the node number of the same level in the second-order neighbors;

[0070] (3) Determine whether there is a node in 2(x)(y) that has two parent nodes or whether there are nodes in 2(x)(y) that are first-order neighbors of each other; if there is a node in 2(x)(y) that meets the above conditions, then the node is classified into the first node set; if the above conditions are not met, then the node is classified into the second node set;

[0071] For example, Figure 2 The ring structure diagram of the electrical island is given. In the diagram, 0 is the root node, 1(1) and 1(2) are the first-order neighbor nodes of 0; if node 2(1)(1) has two parent nodes, there is a ring structure between node 2(1)(1) and its parent nodes, marked as ring 1, and node 2(1)(1) is classified into the first node set; if node 2(1)(1) and node 2(1)(2) are first-order neighbors (connected in the diagram), there is a ring structure between the two nodes and their parent nodes, marked as ring 2, and node 2(1)(1) and node 2(1)(2) are classified into the first node set;

[0072] (4) Repeat the above steps until all nodes in electrical island A are traversed and then stop traversal, and divide node 0 into the second node set.

[0073] In addition, during the traversal process, once it is determined that a node belongs to a ring structure, a connectivity analysis is immediately performed based on the node, and the ring structure corresponding to the node is marked.

[0074] Each electrical island is traversed according to the above method to obtain the first node set and the second node set of each electrical island.

[0075] Step S4: constructing a resource regulation aggregation model for each electrical island based on the preset line flow constraints, the first node set and the second node set.

[0076] In an embodiment of the present application, if for the first node set, its resource regulation aggregation model needs to be constructed by solving an optimization problem; if for the second node set, its resource regulation aggregation model can be directly constructed by algebraic summation of the distribution network-bus branch topology diagram.

[0077] In order to solve the resource regulation capability of the electrical island, the first node set is first optimized and solved, and the two optimization problems of the upward resource regulation capacity and the downward resource regulation capacity of the nodes in the first node set are solved respectively. Then, based on the resource regulation capability of the nodes, the overall resource regulation capability of the first node set is constructed.

[0078] Firstly, according to the sensitivity of each node in the first node set to the associated line and the power flow constraint corresponding to the associated line, the upward resource regulation capacity and the downward resource regulation capacity of each node in the first node set are constrained.

[0079] Because the restrictions of line flow changes on the resource regulation capacity of nodes are taken into account, the resource regulation aggregation model constructed subsequently can adapt to different working conditions and has good portability.

[0080] Among them, the sensitivity of each node to the associated line indicates the degree of influence of the parameter change of the power grid equipment on the power grid line. In the embodiment of the present application, it can also be called the PTDF power flow transfer factor sensitivity, which is mainly used to describe the influence of resource changes on the operation of the line, and can judge the operation stability of the line, which is generally determined by the actual situation. The upward resource adjustment capacity and the downward resource adjustment capacity are actually the maximum and minimum powers that the node can provide.

[0081] Then, according to the upward resource adjustment capacity and the downward resource adjustment capacity of the node, the resource adjustment capacity of the first node set is obtained with the goal of maximizing the total resource adjustment capacity of the first node set.

[0082] The resource adjustment capability of the first node set is specifically calculated as follows:

[0083]

[0084] In the formula, The first node set S I Upward resource adjustment capability, The first node set S I The downward resource adjustment capability, P i u is the upward resource adjustment capacity of node i, P id is the downward resource adjustment capacity of node i, S I is the first node set, k is the root node of the electrical island to which node i belongs, is the lower limit of the upward resource adjustment capacity of node i, is the upper limit of the upward resource adjustment capacity of node i, N g is the number of nodes in the first node set, N l is the number of lines, is the sensitivity of each node to line j, P l,j is the lower limit of the line power flow constraint of line j, is the upper limit of the line power flow constraint of line j, is the upward resource adjustment capacity of node i, is the lower limit of the downward resource adjustment capacity of node i, is the upper limit of the downward resource adjustment capacity of node i, The downward resource adjustment capacity of node i.

[0085] As an improvement to the above solution, the upper and lower limits of the upward / downward resource adjustment capacity are specified by actual demand, or determined by the difference between the rated maximum and minimum power of the device and the current device power. Set to 0, it can be understood that the device represented by node i has downward resource adjustment capacity, and the minimum downward resource adjustment capacity is 0. Similarly, it can be defined is 0, which can be understood as the device represented by node i has downward resource adjustment capacity, and the minimum downward resource adjustment capacity is 0.

[0086] Then, the resource adjustment capability of the second node set is calculated by an algebraic summation method. In order to better illustrate the algebraic summation process, Figure 3 The non-cyclic structure diagram provided in the embodiment of the present application takes node 2(1)(1) as an example, and the limit of its upward resource adjustment capacity is The output limit of the line connected to it is Recorded as Similarly Then there is That is, the actual sum of the upward resource adjustment limits of all branches on node 1 (1). According to the above steps, the resource adjustment capability of the second node set can be finally calculated.

[0087] A resource regulation aggregation model of each electrical island is constructed according to the resource regulation capabilities of the second node set and the first node set.

[0088] The resource regulation aggregation model of each electrical island is recorded as (P a , P ua , P da )t , P a The current active power of the resource adjustment aggregation model, subscript t is the timestamp corresponding to the model construction. In the embodiment of the present application, the calculation is performed on a certain time t. If multiple times are to be calculated in other embodiments, the timestamp can be used to judge different times.

[0089] Step S5, integrating the resource regulation aggregation model to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

[0090] In the embodiment of the present application, after obtaining the resource regulation aggregation model of all electrical islands, these models are integrated into a distribution network flexible resource scheduling model to predict the overall resource regulation capability of the distribution network. The distribution network flexible resource scheduling model can be used to construct relevant models of the distribution network participating in the power market, because it can accurately describe the resource regulation capability of the distribution network and optimize and solve some economic problems in the power market.

[0091] Implementing the embodiments of the present application has the following beneficial effects:

[0092] The embodiment of the present application first obtains a distribution network-bus branch topology diagram that can accurately describe the physical structure of the distribution network, and then divides the distribution network-bus branch topology diagram into multiple electrical islands, and then separately models them in parallel with the electrical islands in the subsequent units, thereby improving the calculation rate by reducing the amount of calculation; for each electrical island, node traversal is performed, and the nodes are divided into the first node set or the second node set to achieve the classification of different types of nodes, optimize and solve the nodes of the subsequent ring structure, and directly perform algebraic summation on the nodes of the non-ring structure to provide data support; then based on these node sets, on the basis of line flow constraints, considering the mutual influence between nodes, a corresponding resource regulation aggregation model is constructed for each electrical island to describe the resource allocation capability of each electrical island. Moreover, because different electrical islands are modeled separately and different working conditions are considered through line flow constraints, the constructed resource regulation aggregation model has high transferability and is suitable for different working conditions. Finally, the models of all electrical islands are integrated to obtain a distribution network flexible resource scheduling model for predicting the entire distribution network, so as to accurately evaluate the resource regulation capability of the distribution network.

[0093] Second embodiment

[0094] Further, in order to execute the resource regulation capability evaluation system of the distribution network corresponding to the above method embodiment to achieve the corresponding functions and technical effects, Figure 4 A structural diagram of a distribution network resource regulation capability evaluation system is provided. For ease of description, only the parts related to this embodiment are shown. The distribution network resource regulation capability evaluation system provided by the embodiment of the present application includes:

[0095] The physical topology building module 201 is used to build a distribution network-bus branch topology diagram according to the physical structure of the distribution network.

[0096] In the embodiment of the present application, data related to the physical structure of the distribution network, such as device data and line data, are first obtained. Based on these data, a distribution network-bus branch topology diagram is constructed with single-terminal devices as nodes and double-terminal or multi-terminal devices as edges.

[0097] Among them, single-terminal devices include generators, electric vehicles, reactive power compensation devices, loads and energy storage, etc. Double / multi-terminal devices include lines and transformers, etc.

[0098] As an improvement of the above solution, the nodes in the distribution network-bus branch topology diagram need to include the following attributes: adjustable resource type, resource ID, upward resource adjustment capability, downward resource adjustment capability, etc.

[0099] The graph model division module 202 is used to perform parallel division on the preset electrical graph model based on the preset distribution network-bus branch topology graph to obtain a plurality of electrical islands.

[0100] In an embodiment of the present application, the low-voltage side nodes and load nodes in the distribution network-bus branch topology diagram are retrieved; the bus in the distribution network-bus branch topology diagram is used as the root node, and the low-voltage side nodes and load nodes corresponding to the bus are used as leaf nodes to construct a number of electrical islands.

[0101] The node partitioning module 203 is used to traverse the nodes in each electrical island and partition the nodes of the electrical island into the first node set or the second node set of the electrical island according to the node structure of each electrical island.

[0102] In an embodiment of the present application, the ring structure in each electrical island is marked by traversing the nodes of each electrical island; the nodes belonging to the ring structure are divided into the first node set of the corresponding electrical island, and the nodes not belonging to the ring structure are divided into the second node set of the corresponding electrical island.

[0103] The aggregation model building module 204 is used to build a resource regulation aggregation model of each electrical island based on the preset line flow constraints, the first node set and the second node set.

[0104] In an embodiment of the present application, the resource regulation capability of the second node set is calculated by an algebraic summation method; based on the line flow constraint, the upward resource regulation capacity and the downward resource regulation capacity of the nodes in the first node set are optimized to calculate the resource regulation capability of the first node set; and according to the resource regulation capabilities of the second node set and the first node set in each electrical island, a resource regulation aggregation model of each electrical island is generated.

[0105] The resource regulation capability evaluation module 205 is used to integrate the resource regulation aggregation model to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

[0106] In the embodiment of the present application, after obtaining the resource regulation aggregation model of all electrical islands, these models are integrated into a distribution network flexible resource scheduling model to predict the overall resource regulation capability of the distribution network. The distribution network flexible resource scheduling model can be used to construct relevant models of the distribution network participating in the power market, because it can accurately describe the resource regulation capability of the distribution network and optimize and solve some economic problems in the power market.

[0107] In some embodiments, the graph model partitioning module 202 further includes:

[0108] First, find the root node in the distribution network-bus branch topology diagram, that is, the node where the aggregation model needs to be constructed. Because in the new distribution network, there are a large number of aggregates with resource regulation capabilities, and their resource regulation capabilities are jointly determined by different resources in the aggregate. The aggregate can participate in power grid regulation or market transactions as a whole. Therefore, it is necessary to first build the corresponding resource regulation aggregation model in parallel with the aggregate as a unit in the embodiment of this application, and then use these models to evaluate the resource regulation capability of the distribution network as a whole, so as to realize the conversion of ultra-large-scale data calculations into multiple small-scale data calculations.

[0109] Then, starting from the root node, a connectivity analysis is performed on the distribution network-bus branch topology diagram. Specifically, the low-voltage side nodes are searched along the edge of the root node until the load node is reached, indicating that there is no way to go, and the connectivity analysis is completed.

[0110] Then, the root node is used as the busbar, and the low-voltage side nodes and load nodes found from the root node are used as leaf nodes to construct several electrical islands, where each root node corresponds to an electrical island.

[0111] Optionally, the embodiment of the present application uses a 110kV or 220kV bus in the distribution network-bus branch topology diagram as a root node, and uses lower voltage level devices connected to such a bus as leaf nodes.

[0112] In addition, the embodiment of the present application does not limit the number of electrical islands, and uses a calculation engine in a preset database containing distribution network hardware resources to achieve automatic division of electrical islands.

[0113] In some embodiments, the node partitioning module 203 further includes:

[0114] The nodes of an electrical island are traversed to find and mark the ring structure in the electrical island, and then the nodes in the electrical island are divided into the first node set or the second node set according to the marked ring structure. Taking an electrical island as an example, the electrical island is called electrical island A. The specific process of dividing the nodes of electrical island A is as follows:

[0115] (1) First, mark the root node of electrical island A as node 0, determine the first-order neighbor node of node 0, and mark the first-order neighbor node as 1(x); where 1 in 1(x) indicates that it is a first-order neighbor of node 0, and the x in the brackets indicates the node number of the same level;

[0116] (2) Starting from the first-order neighbor node, traverse in parallel to find the first-order neighbor node of each 1(x), that is, the second-order neighbor node of the root node, and mark the second-order neighbor node as 2(x)(y); wherein,

[0117] The y in 2(x)(y) represents the node number of the same level in the second-order neighbors;

[0118] (3) Determine whether there is a node in 2(x)(y) that has two parent nodes or whether there are nodes in 2(x)(y) that are first-order neighbors of each other; if there is a node in 2(x)(y) that meets the above conditions, then the node is classified into the first node set; if the above conditions are not met, then the node is classified into the second node set;

[0119] For example, Figure 2 The ring structure diagram of the electrical island is given. In the diagram, 0 is the root node, 1(1) and 1(2) are the first-order neighbor nodes of 0; if node 2(1)(1) has two parent nodes, there is a ring structure between node 2(1)(1) and its parent nodes, marked as ring 1, and node 2(1)(1) is classified into the first node set; if node 2(1)(1) and node 2(1)(2) are first-order neighbors (connected in the diagram), there is a ring structure between the two nodes and their parent nodes, marked as ring 2, and node 2(1)(1) and node 2(1)(2) are classified into the first node set;

[0120] (4) Repeat the above steps until all nodes in electrical island A are traversed and then stop traversal, and divide node 0 into the second node set.

[0121] In addition, during the traversal process, once it is determined that a node belongs to a ring structure, a connectivity analysis is immediately performed based on the node, and the ring structure corresponding to the node is marked.

[0122] Each electrical island is traversed according to the above method to obtain the first node set and the second node set of each electrical island.

[0123] In some embodiments, the aggregation model building module 204 further includes:

[0124] If it is for the first node set, its resource regulation aggregation model needs to be constructed by solving the optimization problem; if it is for the second node set, its resource regulation aggregation model can be directly constructed by algebraic summation of the distribution network-bus branch topology graph.

[0125] In order to solve the resource regulation capability of the electrical island, the first node set is first optimized and solved, and the two optimization problems of the upward resource regulation capacity and the downward resource regulation capacity of the nodes in the first node set are solved respectively. Then, based on the resource regulation capability of the nodes, the overall resource regulation capability of the first node set is constructed.

[0126] Firstly, according to the sensitivity of each node in the first node set to the associated line and the power flow constraint corresponding to the associated line, the upward resource regulation capacity and the downward resource regulation capacity of each node in the first node set are constrained.

[0127] Because the restrictions of line flow changes on the resource regulation capacity of nodes are taken into account, the resource regulation aggregation model constructed subsequently can adapt to different working conditions and has good portability.

[0128] Among them, the sensitivity of each node to the associated line indicates the degree of influence of the parameter change of the power grid equipment on the power grid line. In the embodiment of the present application, it can also be called the PTDF power flow transfer factor sensitivity, which is mainly used to describe the influence of resource changes on the operation of the line, and can judge the operation stability of the line, which is generally determined by the actual situation. The upward resource adjustment capacity and the downward resource adjustment capacity are actually the maximum and minimum powers that the node can provide.

[0129] Then, according to the upward resource adjustment capacity and the downward resource adjustment capacity of the node, the resource adjustment capacity of the first node set is obtained with the goal of maximizing the total resource adjustment capacity of the first node set.

[0130] The resource adjustment capability of the first node set is specifically calculated as follows:

[0131]

[0132] In the formula, The first node set S I Upward resource adjustment capability, The first node set S I The downward resource adjustment capability, P i u is the upward resource adjustment capacity of node i, P i d is the downward resource adjustment capacity of node i, S Iis the first node set, k is the root node of the electrical island to which node i belongs, is the lower limit of the upward resource adjustment capacity of node i, is the upper limit of the upward resource adjustment capacity of node i, N g is the number of nodes in the first node set, N l is the number of lines, is the sensitivity of each node to line j, P l,j is the lower limit of the line power flow constraint of line j, is the upper limit of the line power flow constraint of line j, is the upward resource adjustment capacity of node i, is the lower limit of the downward resource adjustment capacity of node i, is the upper limit of the downward resource adjustment capacity of node i, The downward resource adjustment capacity of node i.

[0133] As an improvement to the above solution, the upper and lower limits of the upward / downward resource adjustment capacity are specified by actual demand, or determined by the difference between the rated maximum and minimum power of the device and the current device power. Set to 0, it can be understood that the device represented by node i has downward resource adjustment capacity, and the minimum downward resource adjustment capacity is 0. Similarly, it can be defined is 0, which can be understood as the device represented by node i has downward resource adjustment capacity, and the minimum downward resource adjustment capacity is 0.

[0134] Then, the resource adjustment capability of the second node set is calculated by an algebraic summation method. In order to better illustrate the algebraic summation process, Figure 3 The non-cyclic structure diagram provided in the embodiment of the present application takes node 2(1)(1) as an example, and the limit of its upward resource adjustment capacity is The output limit of the line connected to it is Recorded as Similarly Then there is That is, the actual sum of the upward resource adjustment limits of all branches on node 1 (1). According to the above steps, the resource adjustment capability of the second node set can be finally calculated.

[0135] A resource regulation aggregation model of each electrical island is constructed according to the resource regulation capabilities of the second node set and the first node set.

[0136] The resource regulation aggregation model of each electrical island is recorded as (P a , P ua , P da )t,P aThe current active power of the resource adjustment aggregation model, subscript t is the timestamp corresponding to the model construction. In the embodiment of the present application, the calculation is performed on a certain time t. If multiple times are to be calculated in other embodiments, the timestamp can be used to judge different times.

[0137] Implementing the embodiments of the present application has the following beneficial effects:

[0138] The embodiment of the present application obtains several electrical islands that can be considered to be independently operated by parallel partitioning the distribution network-busbar branch topology diagram that describes the physical structure of the distribution network, and retrieves the ring structure of the electrical island, divides the nodes that constitute the ring structure into the first node set, and divides the nodes that do not constitute the ring structure into the second node set, and then optimizes and solves the first node set respectively, performs algebraic summation on the second node set, accurately predicts the resource regulation capability of each electrical island, and constructs a corresponding resource regulation aggregation model. Finally, the models of all electrical islands are integrated to obtain a distribution network flexible resource scheduling model for predicting the entire distribution network, so as to accurately evaluate the resource regulation capability of the distribution network.

[0139] An embodiment of the present application also provides a storage medium, which stores computer-readable program code. When the computer-readable program code is executed, the steps of the above-mentioned method for evaluating the resource regulation capability of a distribution network are implemented.

[0140] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for evaluating the resource regulation capability of a distribution network, characterized in that: include: According to the physical structure of the distribution network, construct the distribution network-bus branch topology diagram; The distribution network-busbar branch topology diagram is divided in parallel to obtain a plurality of electrical islands; Traversing the nodes in each electrical island, and dividing the nodes of the electrical island into a first node set or a second node set of the electrical island according to the node structure of each electrical island; Based on the preset line flow constraints, the first node set and the second node set, construct a resource regulation aggregation model for each electrical island; The resource regulation aggregation model is integrated to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

2. The method for evaluating the resource regulation capability of a distribution network according to claim 1, characterized in that: The distribution network-busbar branch topology diagram is divided in parallel to obtain a plurality of electrical islands, specifically: Retrieving low-voltage side nodes and load nodes in the distribution network-bus branch topology diagram; The busbar in the distribution network-busbar branch topology diagram is taken as the root node, and the low-voltage side nodes and load nodes corresponding to the busbar are taken as leaf nodes to construct a plurality of electrical islands.

3. The method for evaluating the resource regulation capability of a distribution network according to claim 1, characterized in that: The traversing of the nodes in each electrical island and dividing the nodes of the electrical island into the first node set or the second node set of the electrical island according to the node structure of each electrical island is specifically as follows: By traversing the nodes of each electrical island, the ring structure in each electrical island is marked; The nodes belonging to the ring structure are divided into a first node set of the corresponding electrical island, and the nodes not belonging to the ring structure are divided into a second node set of the corresponding electrical island.

4. The method for evaluating the resource regulation capability of a distribution network according to claim 3, characterized in that: The ring structure in each electrical island is marked by traversing the nodes of each electrical island, specifically: Determine the first-order neighbor node of the root node of the electrical island, and traverse downward from the first-order neighbor node; If the first node currently traversed meets the preset ring construction condition, connectivity analysis is performed on the electrical island according to the first node, and the ring structure corresponding to the first node is marked; The traversal is stopped after all nodes in the electrical island are traversed.

5. The method for evaluating the resource regulation capability of a distribution network according to claim 4, characterized in that: The ring construction conditions are specifically: If the first node has two parent nodes or there is a node at the same layer that is a first-order neighbor of the first node, it means that the first node meets the ring construction condition.

6. The method for evaluating the resource regulation capability of a distribution network according to claim 1, characterized in that: The resource regulation aggregation model of each electrical island is constructed based on the preset line flow constraint, the first node set and the second node set, specifically: Calculating the resource adjustment capability of the second node set by an algebraic summation method; Based on the line power flow constraint, optimizing the upward resource regulation capacity and the downward resource regulation capacity of the nodes in the first node set to calculate the resource regulation capability of the first node set; A resource regulation aggregation model of each electrical island is generated according to the resource regulation capabilities of the second node set and the first node set in each electrical island.

7. The method for evaluating the resource regulation capability of a distribution network according to claim 6, characterized in that: The optimizing the upward resource adjustment capacity and the downward resource adjustment capacity of the nodes in the first node set based on the line flow constraint to calculate the resource adjustment capability of the first node set is specifically: According to the sensitivity of each node in the first node set to the associated line and the power flow constraint corresponding to the associated line, constraining the upward resource regulation capacity and the downward resource regulation capacity of each node in the first node set; The resource adjustment capacity of the first node set is calculated based on the upward resource adjustment capacity and the downward resource adjustment capacity with the goal of maximizing the total resource adjustment capacity.

8. The method for evaluating the resource regulation capability of a distribution network according to claim 7, characterized in that: The resource adjustment capability of the first node set is specifically: The resource adjustment capability is specifically calculated as follows: In the formula, The first node set S I Upward resource adjustment capability, The first node set S I The downward resource adjustment capability, P i u is the upward resource adjustment capacity of node i, P i d is the downward resource adjustment capacity of node i, S I is the first node set, k is the root node of the electrical island to which node i belongs, is the lower limit of the upward resource adjustment capacity of node i, is the upper limit of the upward resource adjustment capacity of node i, N g is the number of nodes in the first node set, N l is the number of lines, is the sensitivity of each node to line j, P l,j is the lower limit of the line power flow constraint, is the upper limit of the line power flow constraint, is the upward resource adjustment capacity of node i, is the lower limit of the downward resource adjustment capacity of node i, is the upper limit of the downward resource adjustment capacity of node i, The downward resource adjustment capacity of node i.

9. A distribution network resource regulation capability evaluation system, characterized in that: include: Physical topology building module, graph model partitioning module, node partitioning module, aggregation model building module and resource regulation capability evaluation module; Wherein, the physical topology construction module is used to construct a distribution network-bus branch topology diagram according to the physical structure of the distribution network; The graph model partitioning module is used to perform parallel partitioning on the distribution network-bus branch topology graph to obtain a plurality of electrical islands; The node division module is used to traverse the nodes in each electrical island, and divide the nodes of the electrical island into the first node set or the second node set of the electrical island according to the node structure of each electrical island; The aggregation model building module is used to build a resource regulation aggregation model of each electrical island based on the preset line flow constraints, the first node set and the second node set; The resource regulation capability evaluation module is used to integrate the resource regulation aggregation model to obtain a distribution network flexible resource scheduling model to evaluate the resource regulation capability of the distribution network.

10. A storage medium, characterized in that: The storage medium stores computer-readable program codes, which, when executed, implement the steps of a method for evaluating resource regulation capability of a distribution network according to any one of claims 1 to 8.

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