Generation system and generation method for similar topological power flow sample of power system

Abstract

The invention discloses a system and a method for generating similar topological power flow samples of an electric power system, and belongs to the technical field of operation analysis and calculation of the electric power system. The basic power flow sample comprises preset nodes and a whole-network CIM connection model; wherein a part of nodes are designated as load nodes, and the other part of nodes are generator nodes; the load of each load node is set to be adjusted to the maximum value; the power grid topology generation module is used for generating a power grid topology structure and generating a plurality of power grid similar topology structures by changing an in-station topology state or an in-station line state; the power grid topology generation module comprises an in-station topology processing unit and a plant-station line topology unit; the plant-station line topology unit is used for changing a plant-station line topology structure by adopting a method of removing a plant-station line; the power grid state quantity generation module is used for generating a plurality of load scenes based on the load maximum value; and the power grid sample storage management module is used for storing and managing characteristic values and identifiers in the load flow calculation samples.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system operation analysis and calculation, and in particular relates to a system and a method for generating power system similar topology flow samples. Background Art

[0002] Samples are the basic data objects in data-driven methods. Data-driven methods are used to study power system operation problems. The most basic problem is to generate a large-scale power flow sample data set. Data-driven methods have a large demand for power flow samples, and the power flow sample data set must be able to fully reflect the needs of the power system operation space. Since the actual operation data has data bias and cannot reflect the full picture of the power system operation space, it is necessary to supplement the generated samples. This problem is called the power flow sample generation problem. In order to solve this problem, the power flow sample generation method is required to be able to quickly generate a large number of samples, and the power flow samples must have a good data distribution.

[0003] Since the topological state of the power system changes in real time with the control of the power system dispatcher, the power grid topology does not remain unchanged. The power system state information is also obtained by analyzing the switchgear under the complete CIM model to obtain the power grid flow state. Considering the potential feasible topological state of the power grid, sample generation should also consider the generation of similar topologies.

[0004] There are two main methods for generating power flow samples of power system under the determined power grid topology: planned power flow method and inverse function method.

[0005] The planned power flow method uses power flow calculation technology. First, the network topology, connection parameters, and some parameters of the nodes of the power system are given, and then based on simple circuit constraints in physics, the problem is transformed into a nonlinear algebraic equation. Solving the equation can obtain all the properties of all nodes that meet the constraints. The main principles are as follows:

[0006] The nodes in the power system are divided into PV nodes, PQ nodes and balancing machine nodes. The attributes of a single node mainly include the active and reactive power injected into the node, the amplitude and phase angle of the voltage, and four attributes. A PV node is a node with given injected active power and voltage amplitude, usually a generator; a PQ node is a node with given injected active and reactive power, usually a load; a balancing machine node is a node with given voltage and phase angle. A power flow sample is defined as an operating point of the power system under a certain steady state, that is, a combination of all node injected power and node voltage when the power system is in a steady state, and its expression is: {{P i ,Q i ,V i ,θ i}|i=0,1,…,N}, where P i is the injected active power of node i, Q iis the injected reactive power of node i, V i is the voltage amplitude at node i, θ i is the voltage phase angle of node i;

[0007] For each node i in the power system, a set of real equations constrains its four variables {P i ,Q i ,V i ,θ i}, the real number equation is as follows:

[0008]

[0009] Among them, δ ij is the voltage phase angle of node i leading node j, G ij and B ij are the real and imaginary parts of the mutual admittance of nodes i and j, respectively. i is the node number. By default, node 0 is the balanced node. n is the total number of nodes. V j is the voltage amplitude of node j. Although the direct use of power flow calculation can be used to determine the purpose of a certain state of the power grid, it is common for power flow not to converge in large systems.

[0010] When the inverse function is used to generate power flow samples, all node voltages can be directly set to generate node injection power to determine the power grid state. The advantage is that the generation speed is fast and the generation results must converge. However, the generated samples are more random and less purposeful, which has a greater impact on the reactive output of the generated samples and less impact on the active output. At the same time, it will affect the load scenario and cannot guarantee that it covers the complete sample space. Summary of the invention

[0011] In view of the problems in the related art, the present invention proposes a generation system and a generation method of power system similar topology flow samples to overcome the above technical problems existing in the existing related art. The present invention mainly considers generating similar topologies of flow samples based on plant information or network-wide CIM connection model information. Secondly, the method of exchanging partial output is adopted in the unit output. Under the condition of ensuring active power balance, the unit output combination is generated according to the specified difference to improve the coverage of the sample space; for the unconverged flow scene, samples with similar active power distribution characteristics are searched as the initial value of the flow calculation to improve the convergence. The node voltage phase angle of the sample definition is used as a storage unique identifier, the voltage phase angle of the generator and load node is used as a characteristic identifier, the load value of the load node is used as a management identifier, and the relative output load ratio is calculated as the active power distribution feature.

[0012] The technical solution of the present invention is implemented as follows: A system for generating power system similar topology flow samples, comprising:

[0013] A basic power flow sample includes pre-set nodes and a CIM connection model of the entire network; wherein a part of the nodes are designated as load nodes and another part of the nodes are designated as generator nodes; and the load of each of the load nodes is set to be adjusted to a maximum value;

[0014] A power grid topology generation module, including an in-station topology processing unit and a plant-station line topology unit; the in-station topology processing unit is used to generate a power grid topology structure, and obtain multiple similar power grid topologies reflected by the basic power flow samples by changing the in-station topology state or the state of the in-station line;

[0015] The power grid topology structure includes an off-station topology structure and an on-station topology structure, wherein the off-station topology structure includes a off-station related nodes and multiple off-station lines, and the on-station topology structure includes b on-station independent nodes, d on-station lines and multiple on-station contact nodes, wherein a, b, and d are all positive integers; each of the off-station related nodes is connected to an on-station contact node via the off-station line, and the on-station contact node is connected to an on-station independent node via the on-station line;

[0016] The in-station topology status includes the status of each in-station independent node, the status of each in-station line and the status of each in-station contact node;

[0017] The plant-station line topology unit modifies the plant-station line topology structure by removing the plant-station line to fit the situation that the power system is shut down for line maintenance;

[0018] The grid state quantity generation module is used to generate multiple load scenarios based on the maximum load value; the output of the generator is evenly distributed to generate basic samples under a single topology and a single load scenario; the output of the unit is adjusted by exchanging output; and the flow calculation sample is obtained by using the Newton-Ray method;

[0019] The power grid sample storage management module stores and manages the characteristic values ​​and identifiers in the power flow calculation samples.

[0020] In the present invention, the data such as the independent nodes within the station, the lines within the station, the communication nodes within the station and the related nodes outside the station are mainly used to describe the power grid topology within the plant; wherein the lines within the station include the connecting devices within the station, and the connecting devices within the station include the transformers.

[0021] Furthermore, the independent node within the station is a node that is not connected to related nodes outside the station, and includes the generator node and the load node; wherein the number of the communication nodes within the station is no more than d.

[0022] Furthermore, in the power grid topology, the state of the switch device is used as a node of the topology, wherein the state of the switch device includes a connected state and a disconnected state;

[0023] Furthermore, the present invention uses the states of all switch devices as nodes of the topology, which undoubtedly includes the intermediate process of switching between different flow states, together with some intermediate states of the whole network topology connection. Pre-calculation and storage in the station is acceptable because the changes in a single power plant are slow;

[0024] In the present invention, if the CIM model information in the station is known, the status of two types of switch components, circuit breakers and disconnectors, are mainly traversed, and the normal operating status topology of the plant is counted and pre-stored. Only when new equipment is added to the plant, the possible status is re-traversed and stored.

[0025] Furthermore, for the power grid topology structure, the topology modification is performed by splitting or merging the intra-station contact nodes; two intra-station contact nodes of the same voltage level are merged into one intra-station contact node, and there is one topological connection situation; for an intra-station topological contact node that is connected to x intra-station lines and a out-of-station nodes, it is split into two intra-station contact nodes, and there are species, where x is a positive integer and x≤d.

[0026] Furthermore, in the plant-station line topology unit, for a power network with m plant-station lines, if one line is removed, there are m situations, and if n lines are removed, there are C m n There are two situations, where m and n are both positive integers. By removing the selected n lines and then performing a topological analysis in conjunction with the in-station topology, the in-station contact nodes and independent nodes that have no electrical connection with the nodes outside the station due to line failure are removed. The state of the in-station topology obtained can determine the topology of the entire network.

[0027] Furthermore, in the power grid state quantity generation module, for a single load scenario, different unit output combinations are generated by exchanging values, and then the output is modified under the condition of ensuring active power balance according to a predetermined difference.

[0028] Furthermore, in the power grid state quantity generation module, for a network with N nodes under a single topology, a certain generator node is designated as a balanced node, and given the voltage amplitudes of the N nodes and the voltage phase angle differences between the N-1 unbalanced nodes and the balanced node, a power flow calculation sample can be determined, that is, 2N-1 characteristic values ​​are used as the unique identifier of a single power flow calculation sample;

[0029] Furthermore, for each power flow calculation sample, the voltage phase angle of the node is obtained as a unique identifier, and the management identifier and the characteristic identifier are determined to calculate the active power distribution characteristics.

[0030] A method for generating power system similar topology flow samples is applied to the above-mentioned power system similar topology flow sample generation system, and the generation method is as follows:

[0031] Step S1: pre-set a basic power flow sample; set the load of the given load node to the maximum value, and set the CIM connection model of the whole network; wherein the load node and the generator node are independent nodes in the station and are not directly connected to the related nodes outside the station;

[0032] Step S2: firstly generate different power grid topology structures, modify the in-station contact nodes in the power grid topology structures, and then modify the line status in the plant-station line topology structure to obtain multiple similar power grid topology structures reflected by the basic power flow samples;

[0033] Step S3: First, based on the maximum load value, generate multiple load scenarios; evenly distribute the output of the generator to generate basic samples under a single topology and a single load scenario; use the method of exchanging output to adjust the unit output; use the Newton method to calculate the power flow and obtain the power flow calculation sample;

[0034] Step S4: determining whether the power flow of the power flow calculation sample has converged;

[0035] Step S5: If the power flow calculation samples converge, the characteristic values ​​and identifiers in the power flow calculation samples are extracted to the power grid sample storage management module for storage and management.

[0036] Further, in step S4, if the power flow of the power flow calculation sample does not converge, the voltage and amplitude of the power flow samples with similar active power distribution characteristics in the generated power flow sample library are searched as the initial values ​​of the Newton method power flow calculation, and then the Newton method power flow calculation is used again for the initial values ​​to obtain the power flow calculation samples, and then it is re-determined whether the power flow of the newly generated power flow calculation sample converges. If it is determined to converge, it goes to step S5, records the number of times the power flow calculation is recalculated after the search, and stops the search if it fails to converge after exceeding the specified number of times, and saves the failed power flow calculation samples for manual analysis.

[0037] Beneficial effects of the present invention:

[0038] (1) First, the present invention generates similar topologies of power flow samples based on plant information or power grid CIM model information, effectively utilizing the existing power grid structure and information, making the generated power flow samples closer to the actual power grid conditions, and improving the practicality and accuracy of the samples. In terms of unit output, the present invention adopts a method of exchanging partial outputs, and generates unit output combinations according to specified differences while ensuring active power balance. This method can generate a variety of unit output combinations, thereby significantly improving the coverage of the sample space and providing a richer and more comprehensive data basis for subsequent power flow analysis, power grid optimization, etc.

[0039] (2) Secondly, for the non-converged power flow scenario, the present invention effectively utilizes the information of existing samples by searching for samples with similar active power distribution characteristics as the initial value of the power flow calculation, reduces the difficulty of power flow calculation convergence, and improves the calculation efficiency and stability. In addition, the present invention defines the node voltage phase angle as the storage unique identifier, the voltage phase angle of the generator node and the load node as the feature identifier, and the load value of the load node as the management identifier. This identification method makes the management of sample data clearer and more orderly, and is convenient for subsequent feature extraction and analysis.

[0040] (3) Finally, by calculating the relative output load ratio as the active power distribution characteristic, the present invention provides a concise and intuitive way to describe the distribution of active power in the power grid, which helps to quickly identify the operating status and potential problems of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the double-mother main wiring of the present invention;

[0042] Figure 2 A schematic diagram of the structure of the intra-station contact node splitting and merging of the present invention;

[0043] Figure 3 The present invention is a flow chart of a method for generating power system similar topology flow samples. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0046] This embodiment provides a system for generating power system similar topology power flow samples, including:

[0047] A basic power flow sample includes pre-set nodes and a CIM connection model of the entire network; wherein a part of the nodes are designated as load nodes and another part of the nodes are designated as generator nodes; and the load of each of the load nodes is set to be adjusted to a maximum value;

[0048] A power grid topology generation module, including an in-station topology processing unit and a plant-station line topology unit;

[0049] The in-station topology processing unit is used to generate a power grid topology structure, and obtain a plurality of similar power grid topologies reflected by the basic power flow samples by changing the in-station topology state or the state of the in-station lines;

[0050] The power grid topology structure includes an off-station topology structure and an on-station topology structure, wherein the off-station topology structure includes a off-station related nodes and multiple off-station lines, and the on-station topology structure includes b on-station independent nodes, d on-station lines and multiple on-station contact nodes, wherein a, b, and d are all positive integers; each of the off-station related nodes is connected to an on-station contact node via the off-station line, and the on-station contact node is connected to an on-station independent node via the on-station line;

[0051] The in-station topology status includes the status of each in-station independent node, the status of each in-station line and the status of each in-station contact node;

[0052] The plant-station line topology unit modifies the plant-station line topology structure by removing the plant-station line to fit the situation that the power system is shut down for line maintenance;

[0053] The grid state quantity generation module is used to generate multiple load scenarios based on the maximum load value; the output of the generator is evenly distributed to generate basic samples under a single topology and a single load scenario; the output of the unit is adjusted by exchanging output; and the flow calculation sample is obtained by using the Newton-Ray method;

[0054] The power grid sample storage management module stores and manages the characteristic values ​​and identifiers in the power flow calculation samples.

[0055] In this embodiment, the data such as the independent nodes within the station, the lines within the station, the communication nodes within the station and the related nodes outside the station are mainly used to describe the power grid topology within the plant; wherein, the lines within the station include the connection equipment within the station, and the connection equipment within the station includes the transformer.

[0056] Specifically, the independent node within the station is a node that is not connected to related nodes outside the station, and includes the generator node and the load node; wherein the number of the communication nodes within the station is no more than d.

[0057] Specifically, in the power grid topology, the state of the switch device is used as a node of the topology, wherein the state of the switch device includes a connected state and a disconnected state;

[0058] More specifically, this embodiment uses the states of all switch devices as nodes of the topology, which undoubtedly includes the intermediate process of switching between different power flow states, together with some intermediate states of the whole network topology connection. Pre-calculation and storage in the station is acceptable because the changes in a single power plant are slow;

[0059] In this embodiment, if the CIM model information in the station is known, the status of two types of switch components, circuit breakers and disconnectors, is mainly traversed, and the normal operation status topology of the plant and station is counted and pre-stored. Only when new equipment is added to the plant and station, the possible status is re-traversed and stored;

[0060] like Figure 1 As shown, taking the double mother main connection of a power plant or substation as an example, it includes 6 high-voltage lines (WL1, WL2, WL3, WL4, WL5 and WL6), 2 transformers incoming lines; the specific connection equipment of the 2 transformers is related to the type of plant and station. For power plants, the transformers are connected to generators, and for substations, they are connected to other plants and stations; the 6 outgoing lines are connected to multiple different plants and stations respectively;

[0061] Among them, 6 high-voltage lines are connected to at most 6 different power plants and stations;

[0062] The isolating switches or circuit breakers in the substation are allowed to present a topological state of high-voltage section connection or low-voltage section connection in the flow sample; the traversal method is used to set the state of each switch, and unreasonable operating states are eliminated, and then a topological analysis is performed to obtain all possible connection states in the station.

[0063] Specifically, in this embodiment, if a random small-amplitude topology modification / uncertain plant-specific CIM model is adopted, the topology modification of the power grid topology structure can be performed by splitting or merging the intra-station contact nodes; merging two intra-station contact nodes of the same voltage level into one intra-station contact node, and there is one topological connection situation; for an intra-station contact node connected to x intra-station lines and a external nodes, it is split into two intra-station contact nodes, and the connection situations are species, where x is a positive integer and x≤d.

[0064] like Figure 2As shown in the figure, the in-station contact nodes connected to multiple devices are split, or the in-station contact nodes are merged. In the case of 6 off-station related nodes, 2 independent in-station nodes, and 2 in-station lines, there may be 1 or 2 in-station contact nodes. The number of in-station contact nodes after splitting is no more than the number of in-station lines. There are 1 possible situations for a single in-station contact node, and 2 possible topological connection situations for two in-station contact nodes. It should be noted that the type of main electrical connection of the plant will affect the topological state, and some states cannot be achieved due to the number of switchgear.

[0065] Specifically, in the plant-station line topology unit, for a power network with m plant-station lines, if one line is removed, there are m situations, and if n lines are removed, there are In this case, m and n are both positive integers. The topology structure of the entire network is determined by removing the selected n lines and then performing a topological analysis in conjunction with the in-station topology. In this way, the in-station contact nodes and independent nodes that have no electrical connection with the nodes outside the station due to line failure are removed, and the state of the in-station topology is obtained to determine the topology structure of the entire network.

[0066] Specifically, in the power grid state quantity generation module, for a single load scenario, different unit output combinations are generated by exchanging values, and then the output is modified under the condition of ensuring active power balance according to a predetermined difference.

[0067] Specifically, in the power grid state quantity generation module, for a network with N nodes under a single topology, a certain generator node is designated as a balanced node, and given the voltage amplitudes of the N nodes and the voltage phase angle differences between the N-1 unbalanced nodes and the balanced node, a power flow calculation sample can be determined, that is, 2N-1 characteristic values ​​are used as the unique identifier of a single power flow calculation sample;

[0068] Considering the problem of similar topology, the current method of generating similar topology will affect the total number of nodes, but will not affect the number of load nodes and generator nodes. Only the voltage amplitude and voltage phase angle of load nodes and generator nodes can be used as feature identifiers to describe the state of the power grid, but due to the problem of multiple solutions of power flow, the state of the power grid cannot be uniquely determined. For example, for a network with M load nodes and generator nodes, its characteristic values ​​are M voltage amplitudes and M-1 node voltage phase angle differences, and a total of 2M-1 characteristic values ​​can be used as feature identifiers.

[0069] Based on the output of a certain generator, calculate the relative values ​​of each generator output and load as the active power distribution characteristics. For example, if generator e is set as the basis, its output is 100MW, generator f is 50MW, and g load is 90MW, then the active power distribution characteristics are arranged as [1, 0.5, 0.9] according to e, f, g;

[0070] For the power grid, the injected active power of the load node is more valuable for reference, and can be matched to similar scenarios more quickly, and can be regarded as belonging to the same power flow problem; the power flow samples are split by gridding, and a single grid is regarded as a load scenario, and the load value interval of the load node is used as a management identifier;

[0071] For example, for each load node in its possible range, a step size of 100MW is used as the benchmark demand. For example, if the possible load range of any load node is 0-900MW, there are 10 benchmark demands. Taking half of the step size as the basis for division, for a flow sample with 4 load nodes, if its load demand is [480, 710, 890, 770], it is classified into the load demand scenario of [500, 700, 900, 800].

[0072] More specifically, for each power flow calculation sample, the voltage phase angle of the node is obtained as a unique identifier, and the management identifier and the characteristic identifier are determined to calculate the active power distribution characteristics.

[0073] like Figure 3 As shown, this embodiment also provides a method for generating power system similar topology flow samples, which is applied to the above-mentioned power system similar topology flow sample generation system, and the generation method is as follows:

[0074] Step S1: pre-set a basic power flow sample; set the load of the given load node to the maximum value, and set the CIM connection model of the whole network; wherein the load node and the generator node are independent nodes in the station and are not directly connected to the related nodes outside the station;

[0075] Step S2: firstly generate different power grid topology structures, modify the in-station contact nodes in the power grid topology structures, and then modify the line status in the plant-station line topology structure to obtain multiple similar power grid topology structures reflected by the basic power flow samples;

[0076] Step S3: First, based on the maximum load value, generate multiple load scenarios; evenly distribute the output of the generator to generate basic samples under a single topology and a single load scenario; use the method of exchanging output to adjust the unit output; use the Newton method to calculate the power flow and obtain the power flow calculation sample;

[0077] Step S4: determining whether the power flow of the power flow calculation sample has converged;

[0078] Step S5: If the power flow calculation samples converge, the characteristic values ​​and identifiers in the power flow calculation samples are extracted to the power grid sample storage management module for storage and management.

[0079] Specifically, in step S4, if the power flow of the power flow calculation sample does not converge, the voltage and amplitude of the power flow samples with similar active power distribution characteristics in the generated power flow sample library are searched as the initial values ​​of the Newton method power flow calculation, and then the Newton method power flow calculation is used again for the initial values ​​to obtain the power flow calculation sample, and then it is re-determined whether the power flow of the newly generated power flow calculation sample converges. If it is determined to converge, it enters step S5, records the number of times the power flow calculation is recalculated after the search, and stops the search if it fails to converge after exceeding the specified number of times, and saves the failed power flow calculation sample for manual analysis.

[0080] Given a basic sample adjusted by experts; given the load node load is the maximum value; given the whole network CIM connection model. Load nodes and generator nodes are usually independent nodes within the station and are not directly connected to related nodes outside the station.

[0081] The specific process of a method for generating power system similar topology flow samples is as follows:

[0082] Firstly, different power grid topologies are generated, the in-station contact nodes are modified, and the line states in the plant-station line topology are modified to obtain other possible topological states reflected by the basic power flow samples.

[0083] Secondly, for a single determined topology, it is divided into three steps: determining the load, determining the unit output, and randomly adjusting the voltage reactive power. For the demand range of a given load node, the total load is calculated, and the unit output combination is adjusted on the output combination of the basic sample. First, the generator output is set as evenly as possible, and two generators are randomly selected to exchange part of the output dP. One generator output increases dP, and the other decreases dP. The size of dP is related to the upper and lower limits of the generator output and is set to an integer multiple of the determined value p to ensure that there is a significant difference in the output after adjustment. For a single generator, if its upper limit is Pmax and its lower limit is Pmin, the uniform output under a certain load scenario is Pout, and its adjustable range is (Pmax-Pout) / p+(Pout-Pmin) / p=w. First specify the total number of load changes, and select the number of positive changes and the number of negative changes.

[0084] For example, a single generator can be adjusted up to 5 levels and down to 5 levels. Then the sum of the adjustment levels of all generators should be 0. The sum of positive adjustments should be equal to the sum of negative adjustments, and the sum of positive adjustments is defined as the total load times. If there are 10 generators, given a total load adjustment of 10 levels, 10 is split into multiple positive integer combinations such as {1, 5, 1, 3}, and the adjustment number does not exceed the adjustable capacity of the generator. Then select the generator to increase the output, and select some combinations to select the generator to reduce the output. The generators that are adjusted up and down must not be repeated.

[0085] A single power flow sample can be obtained by using the Newton-Raphson method. Since the power flow method may not converge, for the generated power flow samples, find samples with similar active output distribution, use their voltage phase angle as the initial value of the Newton-Raphson method, and recalculate to improve convergence.

[0086] For each power flow sample, the node voltage phase angle is obtained as a unique identifier, and the management identifier and feature identifier are determined to calculate the active power distribution characteristics.

[0087] First, this embodiment generates similar topologies of power flow samples based on plant information or power grid CIM (Common Information Model) model information, effectively utilizing the existing power grid structure and information, making the generated power flow samples closer to the actual power grid conditions and improving the practicality and accuracy of the samples.

[0088] Secondly, in terms of unit output, this embodiment adopts the method of exchanging partial outputs, and generates unit output combinations according to specified differences while ensuring active power balance. This method can generate a variety of unit output combinations, thereby significantly improving the coverage of the sample space and providing a richer and more comprehensive data foundation for subsequent power flow analysis, power grid optimization, etc.

[0089] Thirdly, for the non-converged power flow scenario, this embodiment effectively utilizes the information of existing samples by searching for samples with similar active power distribution characteristics as the initial values ​​of the power flow calculation, reduces the difficulty of power flow calculation convergence, and improves calculation efficiency and stability.

[0090] Moreover, this embodiment defines the node voltage phase angle as a storage unique identifier, the voltage phase angle of the generator node and the load node as a feature identifier, and the load value of the load node as a management identifier. This identification method makes the management of sample data clearer and more orderly, and facilitates subsequent feature extraction and analysis.

[0091] Finally, by calculating the relative output load ratio as the active power distribution feature, this embodiment provides a concise and intuitive way to describe the distribution of active power in the power grid, which helps to quickly identify the operating status and potential problems of the power grid.

[0092] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A system for generating power system similar topology flow samples, characterized in that: include: A basic power flow sample includes pre-set nodes and a CIM connection model of the entire network; wherein a part of the nodes are designated as load nodes and another part of the nodes are designated as generator nodes; and the load of each of the load nodes is set to be adjusted to a maximum value; A power grid topology generation module, including an in-station topology processing unit and a plant-station line topology unit; the in-station topology processing unit is used to generate a power grid topology structure, and obtain multiple similar power grid topologies reflected by the basic power flow samples by changing the in-station topology state or the state of the in-station line; The power grid topology structure includes an off-station topology structure and an on-station topology structure, wherein the off-station topology structure includes a off-station related nodes and multiple off-station lines, and the on-station topology structure includes b on-station independent nodes, d on-station lines and multiple on-station contact nodes, wherein a, b, and d are all positive integers; each of the off-station related nodes is connected to an on-station contact node via the off-station line, and the on-station contact node is connected to an on-station independent node via the on-station line; The in-station topology status includes the status of each in-station independent node, the status of each in-station line and the status of each in-station contact node; The plant-station line topology unit modifies the plant-station line topology structure by removing the plant-station line to fit the situation that the power system is shut down for line maintenance; The grid state quantity generation module is used to generate multiple load scenarios based on the maximum load value; the output of the generator is evenly distributed to generate basic samples under a single topology and a single load scenario; the output of the unit is adjusted by exchanging output; and the flow calculation sample is obtained by using the Newton-Ray method; The power grid sample storage management module stores and manages the characteristic values ​​and identifiers in the power flow calculation samples.

2. A system for generating power system similar topology flow samples according to claim 1, characterized in that: The independent node within the station is a node that is not connected to related nodes outside the station, and includes the generator node and the load node; wherein the number of the communication nodes within the station is no more than d.

3. A system for generating power system similar topology flow samples according to claim 1, characterized in that: In the power grid topology, the state of the switch device is used as a node of the topology, wherein the state of the switch device includes a connected state and a disconnected state.

4. A system for generating power system similar topology flow samples according to claim 1, characterized in that: For the power grid topology structure, the topology modification is performed by splitting or merging the intra-station contact nodes; merging two intra-station contact nodes of the same voltage level into one intra-station contact node, and there is one topological connection situation; for an intra-station topological contact node that links x intra-station lines and a out-of-station nodes, it is split into two intra-station contact nodes, and there are species, where x is a positive integer and x≤d.

5. A system for generating power system similar topology power flow samples according to claim 1, characterized in that: In the plant-station line topology unit, for a power network with m plant-station lines, if one line is removed, there are m situations, and if n lines are removed, there are There are two situations, where m and n are both positive integers. By removing the selected n lines and then performing a topological analysis in conjunction with the in-station topology, the in-station contact nodes and independent nodes that have no electrical connection with the nodes outside the station due to line failure are removed. The state of the in-station topology obtained can determine the topology of the entire network.

6. A system for generating power system similar topology flow samples according to claim 1, characterized in that: In the power grid state quantity generation module, for a single load scenario, different unit output combinations are generated by exchanging values, and then the output is modified under the condition of ensuring active power balance according to a predetermined difference.

7. A system for generating power system similar topology power flow samples according to claim 1, characterized in that: In the power grid state quantity generation module, for a network with N nodes under a single topology, a certain generator node is designated as a balanced node. Given the voltage amplitudes of the N nodes and the voltage phase angle differences between the N-1 unbalanced nodes and the balanced node, a power flow calculation sample can be determined, that is, 2N-1 characteristic values ​​are used as the unique identifier of a single power flow calculation sample.

8. A system for generating power system similar topology power flow samples according to claim 7, characterized in that: For each power flow calculation sample, the voltage phase angle of the node is obtained as a unique identifier, and the management identifier and feature identifier are determined to calculate the active power distribution characteristics.

9. A method for generating power system similar topology flow samples, characterized in that: Applied to a system for generating power system similar topology flow samples as claimed in any one of claims 1 to 8, the generating method is as follows: Step S1: pre-set a basic power flow sample; set the load of the given load node to the maximum value, and set the CIM connection model of the whole network; wherein the load node and the generator node are independent nodes in the station and are not directly connected to the related nodes outside the station; Step S2: firstly generate different power grid topology structures, modify the in-station contact nodes in the power grid topology structures, and then modify the line status in the plant-station line topology structure to obtain multiple similar power grid topology structures reflected by the basic power flow samples; Step S3: First, based on the maximum load value, generate multiple load scenarios; evenly distribute the output of the generator to generate basic samples under a single topology and a single load scenario; use the method of exchanging output to adjust the unit output; use the Newton method to calculate the power flow and obtain the power flow calculation sample; Step S4: determining whether the power flow of the power flow calculation sample has converged; Step S5: If the power flow calculation samples converge, the characteristic values ​​and identifiers in the power flow calculation samples are extracted to the power grid sample storage management module for storage and management.

10. The generation method according to claim 9, characterized in that: In step S4, if the power flow of the power flow calculation sample does not converge, the voltage and amplitude of the power flow samples with similar active power distribution characteristics in the generated power flow sample library are searched as the initial values ​​of the Newton method power flow calculation, and then the Newton method power flow calculation is used again on the initial values ​​to obtain the power flow calculation sample, and then it is re-determined whether the power flow of the newly generated power flow calculation sample converges. If it is determined to converge, it goes to step S5.

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