UPFC (Unified Power Flow Controller) and reactor optimal configuration method and device in high-voltage power grid

Abstract

The invention discloses an optimal configuration method and device for a UPFC and a reactor in a high-voltage power grid, and the method comprises the steps: analyzing typical load data of a future scene according to a historical load based on a variational mode decomposition method and a center clustering method, and constructing a future typical scene in combination with a future power grid architecture and equipment parameters; any scene is selected for branch power flow margin calculation, and a first control demand set is screened out; performing UPFC and reactor coarse configuration on key out-of-limit lines and nodes of the first control demand set according to the calculated branch power flow margin and branch power to obtain a preliminary configuration scheme; performing branch power flow margin calculation on the preliminarily configured high-voltage power grid system, and screening out a second control demand set; and performing fine configuration solution on the second control demand set through a preset joint optimal configuration model to obtain an optimal configuration scheme. The technical problem that actual configuration is lack of pertinence due to the lack of an optimal configuration scheme of the UPFC and the reactor in a multi-cable urban high-voltage power grid in the prior art can be solved.

Description

Technical Field

[0001] This application relates to the technical field of power systems, and particularly to a method and device for optimizing the configuration of UPFC and reactors in a high-voltage power grid. Background Art

[0002] With the rapid development of urban power grids, the use of high-voltage cables has increased day by day, resulting in an enhanced local capacitive characteristic of the power grid and a gradual weakening of the traditional inductive power grid characteristic; this makes voltage regulation of the power grid complex and difficult. As an advanced power electronic device, the Unified Power Flow Controller (UPFC) can achieve voltage control while regulating power flow, so it has broad application prospects in urban power grids.

[0003] However, the investment cost and operation and maintenance cost of UPFC are much higher than those of traditional reactors, which limits its large-scale application; therefore, the prior art generally configures UPFC and reactors simultaneously in the power grid system to alleviate the input cost of UPFC configuration. However, how to optimize the configuration of UPFC and high-voltage reactors in an urban high-voltage power grid with more cables to achieve active power and voltage optimization control of the power grid is indeed a technical problem that has not been solved yet. Summary of the Invention

[0004] This application provides a method and device for optimizing the configuration of UPFC and reactors in a high-voltage power grid, which is used to solve the technical problem that the prior art lacks an optimization configuration scheme for UPFC and reactors in a multi-cable urban high-voltage power grid system, resulting in a lack of pertinence in actual configuration operations.

[0005] In view of this, the first aspect of this application provides a method for optimizing the configuration of UPFC and reactors in a high-voltage power grid, including:

[0006] Based on the variational mode decomposition method and the k-means clustering method, analyze the typical load data of future scenarios according to the historical load data of the power grid, and construct a future typical scenario in combination with the future power grid architecture and equipment parameters;

[0007] Arbitrarily select a scenario in the future typical scenario for power flow margin calculation, and screen out a first control requirement set, where the first control requirement set includes a first power flow line set and a first voltage node set;

[0008] According to the calculated power flow margin and branch power, perform rough configuration of UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set to obtain a preliminary configuration plan;

[0009] Perform branch power flow margin calculation on the high-voltage power grid system configured according to the preliminary configuration scheme, and screen out the second control requirement set in combination with the branch power flow margin. The second control requirement set includes a second power flow line set and a second voltage node set;

[0010] Perform refined configuration and solution of UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration scheme. The preset joint optimization configuration model includes power flow constraints and non-exceeding constraints.

[0011] Preferably, the method for analyzing typical load data of future scenarios based on variational mode decomposition method and k-means clustering method according to historical load data of the power grid, and constructing future typical scenarios in combination with future power grid architecture and equipment parameters includes:

[0012] Decompose the historical load data of the power grid into main mode components and several sub-mode components based on the variational mode decomposition method;

[0013] Calculate the main mode component of the future load according to the preset growth rate and the main mode component to obtain the future main mode component;

[0014] Divide a plurality of basic load level values based on the future main mode component to obtain a plurality of future basic loads;

[0015] Superimpose several of the sub-mode components onto the future basic load to generate basic load data;

[0016] Perform clustering analysis on the basic load data by using the k-means clustering method to obtain typical load data of future scenarios;

[0017] Construct future typical scenarios in combination with the typical load data, future power grid architecture and equipment parameters.

[0018] Preferably, before analyzing the typical load data of future scenarios based on the variational mode decomposition method and k-means clustering method according to historical load data of the power grid, and constructing future typical scenarios in combination with future power grid architecture and equipment parameters, it further includes:

[0019] Based on the current power grid architecture, determine the architecture and equipment-related parameters of the future power grid system in combination with power grid planning information and power source planning information to obtain future power grid architecture and equipment parameters.

[0020] Preferably, for performing power flow margin calculation on any one scenario in the future typical scenario and screening out the first control requirement set, where the first control requirement set includes a first power flow line set and a first voltage node set, it includes:

[0021] Arbitrarily select a scenario from the future typical scenarios to calculate the power flow margin, and obtain the branch power flow margin and the node voltage margin;

[0022] In the power grid system, screen all the lines with the branch power flow margin less than 0 and all the nodes with the node voltage margin less than 0, and generate the first control requirement set.

[0023] Preferably, based on the calculated power flow margin and branch power, roughly configure UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively, and obtain the preliminary configuration plan, including:

[0024] After obtaining the absolute value of the branch power flow margin, perform a descending order process, and select the first preset number of configured power flow margins in front of the generated margin sequence;

[0025] Based on the power constraint conditions generated by the branch power, determine the key over-limit lines from the first power flow line set according to the configured power flow margin, and configure UPFC;

[0026] If there are nodes in the first voltage node set with the node voltage margin less than the voltage margin threshold, then screen the key over-limit nodes in the first voltage node set according to the voltage margin threshold and configure reactors;

[0027] If there are no nodes in the first voltage node set with the node voltage margin less than the voltage margin threshold, then obtain the second preset number of the node voltage margins with the largest absolute value as the configured voltage margin;

[0028] Screen the key over-limit nodes in the first voltage node set according to the configured voltage margin and configure reactors to generate the preliminary configuration plan.

[0029] Preferably, perform fine configuration and solution of UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model, and obtain the optimized configuration plan. The preset joint optimization configuration model includes power flow constraints and non-over-limit constraints, including:

[0030] Construct a joint optimization configuration objective function based on UPFC and reactors, and configure multiple constraint conditions for the joint optimization configuration objective function to generate a preset joint optimization configuration model. The constraint conditions include power flow constraints and non-over-limit constraints;

[0031] Based on the cuckoo search optimization algorithm, use the preset joint optimization configuration model to optimize and solve the UPFC configuration and reactor configuration plans in the second control requirement set to obtain the optimized configuration plan.

[0032] The second aspect of the present application provides an optimized configuration device for UPFC and reactors in a high-voltage power grid, including:

[0033] A future scenario construction unit, configured to analyze the typical load data of future scenarios based on variational mode decomposition method and k-means clustering method according to the historical load data of the power grid, and construct future typical scenarios in combination with the future power grid architecture and equipment parameters;

[0034] A first power flow screening unit, configured to calculate the power flow margin for any one scenario in the future typical scenario and screen out a first control requirement set, where the first control requirement set includes a first power flow line set and a first voltage node set;

[0035] An over-limit rough configuration unit, configured to perform rough configuration of UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively according to the calculated power flow margin and branch power, so as to obtain a preliminary configuration plan;

[0036] A second power flow screening unit, configured to calculate the branch power flow margin for the high-voltage power grid system configured according to the preliminary configuration plan, and screen out a second control requirement set in combination with the branch power flow margin, where the second control requirement set includes a second power flow line set and a second voltage node set;

[0037] A modeling fine configuration unit, configured to perform fine configuration and solution of UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration plan, where the preset joint optimization configuration model includes power flow constraints and non-over-limit constraints.

[0038] Preferably, the future scenario construction unit is specifically configured to:

[0039] Decompose the historical load data of the power grid into a main modal component and several sub-modal components based on the variational mode decomposition method;

[0040] Calculate the main modal component of the future load according to a preset growth rate and the main modal component to obtain a future main modal component;

[0041] Divide a plurality of basic load level values based on the future main modal component to obtain a plurality of future basic loads;

[0042] Superimpose several of the sub-modal components onto the future basic load to generate basic load data;

[0043] Perform clustering analysis according to the basic load data by using the k-means clustering method to obtain the typical load data of future scenarios;

[0044] Construct future typical scenarios in combination with the typical load data, future power grid architecture and equipment parameters.

[0045] Preferably, the first power flow screening unit is specifically configured to:

[0046] Arbitrarily select a scenario from the future typical scenarios to calculate the power flow margin, and obtain the branch power flow margin and the node voltage margin;

[0047] In the power grid system, screen all lines with a branch power flow margin less than 0 and all nodes with a node voltage margin less than 0, and generate a first control requirement set.

[0048] Preferably, the over-limit rough configuration unit is specifically configured to:

[0049] Obtain the absolute value of the branch power flow margin and perform a descending order process, and select the first preset number of configured power flow margins in front of the generated margin sequence;

[0050] Based on the power constraint conditions generated by the branch power, determine the key over-limit lines from the first power flow line set according to the configured power flow margin, and configure UPFC;

[0051] If there is a node in the first voltage node set with a node voltage margin less than the voltage margin threshold, screen the key over-limit nodes in the first voltage node set according to the voltage margin threshold and configure reactors;

[0052] If there is no node in the first voltage node set with a node voltage margin less than the voltage margin threshold, obtain the second preset number of node voltage margins with the largest absolute value as the configured voltage margin;

[0053] Screen the key over-limit nodes in the first voltage node set according to the configured voltage margin and configure reactors to generate a preliminary configuration plan.

[0054] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0055] In this application, a method for optimizing the configuration of UPFC and reactors in a high-voltage power grid is provided, including: analyzing the typical load data of future scenarios based on the variational mode decomposition method and the k-means clustering method according to the historical load data of the power grid, and constructing future typical scenarios in combination with the future power grid architecture and equipment parameters; arbitrarily selecting a scenario from the future typical scenarios to calculate the power flow margin, and screening out the first control requirement set, which includes the first power flow line set and the first voltage node set; performing a rough configuration of UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set according to the calculated power flow margin and branch power respectively to obtain a preliminary configuration plan; calculating the branch power flow margin of the high-voltage power grid system configured according to the preliminary configuration plan, and screening out the second control requirement set in combination with the branch power flow margin, which includes the second power flow line set and the second voltage node set; solving the refined configuration of UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration plan, and the preset joint optimization configuration model includes power flow constraints and non-over-limit constraints.

[0056] The method for optimizing the configuration of UPFC and reactors in the high-voltage power grid provided by this application constructs future typical scenarios of the power grid system based on the historical load data of the power grid, and then performs hierarchical optimization configuration of UPFC and reactors for the power flow over-limit branches and voltage over-limit nodes of the power grid system on this basis; the primary configuration is a rough configuration operation based on the power flow margin; then the preliminary configuration of the power grid system is completed based on the preliminary configuration plan; the re-configuration is to construct a preset joint optimization configuration model on the basis of the preliminary configuration, and continuously optimize the configuration of UPFC and reactors for the lines and nodes to obtain an optimized configuration plan. This process fully considers the operation of the future urban high-voltage power grid system with more cables through a two-layer progressive optimization configuration method, can ensure the pertinence and effectiveness of the optimized configuration plan, and can meet the actual power grid configuration requirements. Therefore, this application can solve the technical problem that the existing technology lacks an optimized configuration plan for UPFC and reactors in a multi-cable urban high-voltage power grid system, resulting in a lack of pertinence in actual configuration operations. Brief Description of the Drawings

[0057] Figure 1 It is a schematic flow chart of the method for optimizing the configuration of UPFC and reactors in the high-voltage power grid provided by the embodiment of this application;

[0058] Figure 2 It is a schematic structural diagram of the device for optimizing the configuration of UPFC and reactors in the high-voltage power grid provided by the embodiment of this application;

[0059] Figure 3 It is a schematic diagram of the primary and secondary components after VMD decomposition of the historical load data provided by the embodiment of this application;

[0060] Figure 4 It is an example diagram of the future basic load level value obtained after equal division of the main modal components provided by the embodiment of the present application;

[0061] Figure 5 It is an example diagram of 15 kinds of basic load data provided by the embodiment of the present application;

[0062] Figure 6 It is an example diagram of the typical load data obtained after clustering analysis provided by the embodiment of the present application;

[0063] Figure 7 It is a schematic diagram of the principle of the UPFC circuit provided by the embodiment of the present application;

[0064] Figure 8 It is a schematic diagram of the UPFC power regulation principle provided by the embodiment of the present application;

[0065] Figure 9 It is a schematic diagram of the model solving process based on the cuckoo search optimization algorithm provided by the embodiment of the present application. Detailed implementation manners

[0066] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0067] For ease of understanding, please refer to Figure 1 , an embodiment of the method for optimizing the configuration of UPFC and reactors in a high-voltage power grid provided by the present application, includes:

[0068] Step 101: Analyze the typical load data of future scenarios based on the variational mode decomposition method and the k-means clustering method according to the historical load data of the power grid, and construct a future typical scenario in combination with the future power grid architecture and equipment parameters.

[0069] Further, step 101 includes:

[0070] Decompose the historical load data of the power grid into main modal components and several sub-modal components based on the variational mode decomposition method;

[0071] Calculate the main modal component of the future load according to the preset growth rate and the main modal component to obtain the future main modal component;

[0072] Divide multiple basic load level values based on the future main modal component to obtain multiple future basic loads;

[0073] Superimpose a number of sub-modal components onto the future base load to generate base load data;

[0074] Use the k-means clustering method to perform clustering analysis based on the base load data to obtain the typical load data of future scenarios;

[0075] Construct future typical scenarios by combining the typical load data, future power grid architecture, and equipment parameters.

[0076] Furthermore, before step 101, it also includes:

[0077] Based on the current power grid architecture, combine the power grid planning information and power source planning information to determine the architecture and equipment-related parameters of the future power grid system, and obtain the future power grid architecture and equipment parameters.

[0078] It should be noted that this embodiment is designed to meet the active power flow and voltage control requirements of future urban high-voltage power grids with multiple cables. Therefore, the variational mode decomposition method and the k-means clustering method are first used to construct future typical power grid scenarios; the basic construction basis is the historical load data of the current power grid system. In this embodiment, the historical load data of the past year is selected as the analysis basis; the main processes include variational mode decomposition and clustering analysis.

[0079] Specifically, first use the variational mode decomposition method to decompose the power grid historical load data into the main modal component and several sub-modal components; please refer to Figure 3 , in the figure, the example of the main modal component is IMF1, and the sub-modal components include 9 times, namely IMF2~IMF10. The main modal component is the basic form of the load, reflecting the basic change trend of the load; the sub-modal components represent the local change law of the load, including the amplitude and speed of the load change.

[0080] If the load growth rate of the future power grid is set to , then according to the main modal component IMF1, the main modal component of the future load can be calculated, that is, the future main modal component: ; it can be understood that the preset growth rate can be set according to the actual situation and is not limited here. Then, the future main modal component is evenly divided into 4 equal parts according to the value range of the main modal component including the minimum value and the maximum value, and the future maximum load, future minimum load, future average load, and two future intermediate loads can be obtained; these loads are the future base load, please refer to Figure 4 , which can be denoted as , , , , .

[0081] Superimpose all the sub-modal components at the corresponding moments to obtain the sub-modal sum component; then take out its maximum value , minimum value and average value ; then , , are superimposed into the future basic load, and each of the 5 future basic loads needs to be superimposed simultaneously , , the three components; in this way, the load level considering the main form of load change and local influence simultaneously can obtain 15 kinds of basic load data, for details please refer to Figure 5 .

[0082] The central clustering method can be used to perform clustering analysis on the 15 kinds of basic load data, and retain the larger loads with the difference between adjacent two load levels less than 1 / 10 of the total load level, so as to obtain more accurate future typical load data; for the results after clustering, please refer to Figure 6 .

[0083] Combining the obtained typical load data with the future power grid architecture and equipment parameters can construct several typical future power grid scenarios. Among them, the future power grid architecture and specific equipment parameters are both generated according to the current power grid architecture; that is, based on the current power grid grid, combined with the power grid planning information and power source planning information to determine the architecture and equipment-related parameters of the future power grid system, the future power grid architecture and equipment parameters can be obtained.

[0084] Step 102: Arbitrarily select a scenario in the future typical scenario to calculate the power flow margin, and screen out the first control requirement set, which includes the first power flow line set and the first voltage node set.

[0085] Furthermore, step 102 includes:[[]]

[0086] Arbitrarily select a scenario in the future typical scenario to calculate the power flow margin, and obtain the branch power flow margin and the node voltage margin;

[0087] In the power grid system, screen all the lines with the branch power flow margin less than 0, and all the nodes with the node voltage margin less than 0, and generate the first control requirement set.

[0088] It should be noted that by arbitrarily selecting a scenario from the constructed future typical scenarios to calculate the power flow margin, it is possible to analyze which branches and nodes are over-limit according to the margin, and then targeted UPFC and reactor configurations can be carried out; generally, UPFC is configured for the over-limit branches; high-voltage reactors are configured for the over-limit nodes.

[0089] The calculation of power flow margin includes the calculation of branch power flow margin and node voltage margin, and the specific expression is as follows:

[0090]

[0091]

[0092] Among them, and are the branch power flow margin and the node voltage margin respectively; is the maximum allowable value of branch current, is the actual branch current value between node i and node j, is the maximum value of node voltage, is the actual node voltage value of the i-th node. If , it indicates that the branch power flow exceeds the limit; if , it indicates that the node voltage exceeds the upper limit; based on this rule, all the over-limit branches A1 and over-limit nodes B1 in the system can be screened out, that is, the first power flow line set and the first voltage node set, and the first control requirement set is generated.

[0093] Step 103: Coarsely configure UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set according to the calculated power flow margin and branch power, and obtain a preliminary configuration plan.

[0094] Furthermore, step 103 includes:

[0095] Obtain the absolute value of the branch power flow margin and perform a descending order process, and select the first preset number of configured power flow margins in front of the generated margin sequence;

[0096] Based on the power constraint conditions generated by the branch power, determine the key over-limit lines from the first power flow line set according to the configured power flow margin, and configure UPFC;

[0097] If there are nodes in the first voltage node set whose node voltage margin is less than the voltage margin threshold, screen the key over-limit nodes in the first voltage node set according to the voltage margin threshold and configure reactors;

[0098] If there are no nodes in the first voltage node set whose node voltage margin is less than the voltage margin threshold, obtain the second preset number of node voltage margins with the largest absolute value as the configured voltage margin;

[0099] Screen the key over-limit nodes in the first voltage node set according to the configured voltage margin and configure reactors to generate a preliminary configuration plan.

[0100] In the preliminary configuration scheme of this embodiment, UPFCs and reactors are not configured for all the over-limit branches and over-limit nodes in the first power flow line set and the first voltage node set. Instead, several key over-limit targets are selected for targeted configuration. For example, for configuring a UPFC on a branch, the absolute values of the calculated branch power flow margins for all branches are sorted in descending order to obtain a margin sequence. Then, several branches corresponding to the larger margin values are selected from the front of the margin sequence for UPFC configuration. The first preset quantity can be set according to the actual situation. The first preset quantity in this embodiment is 5, that is, 5 lines with the largest branch power flow margins are selected from the first power flow line set A1 for UPFC configuration.

[0101] It should be noted that when configuring a UPFC, the active power and reactive power of the branch need to meet the power constraint conditions for the UPFC configuration to be successful. For example: ; where 、 are the active power and reactive power of the branch respectively, 、 are the maximum allowable active power and maximum allowable reactive power of the branch.

[0102] Please refer to Figure 7 and Figure 8 , under stable conditions, the tie-line power after installing the UPFC satisfies:

[0103]

[0104] where 、 are the voltage phasors of node i and node j respectively, is the equivalent injection potential phasor of the UPFC, is the complex impedance, represents the conjugate operation.

[0105] If it is assumed that , , , , then the branch active power and the reactive power can be expressed as:

[0106]

[0107]

[0108] where 、 are the effective values of the voltages of node i and node j respectively, is the amplitude of the equivalent injection potential of the UPFC, 、 are the phase of the equivalent injection potential of the UPFC and the phase of the voltage at node j, respectively, is the impedance angle of branch ij.

[0109] If UPFC control is performed after the installation of the UPFC, the active power and reactive power on the branch can be recorded as 、 , expressed as:

[0110]

[0111] Solving these two control equations, if there are numerical solutions to these two power equations, it can be considered that after configuring the UPFC, the branch power flow of the system can be adjusted to the specified value, that is, the UPFC configuration is an effective configuration. Therefore, the active power and reactive power of the branch with the UPFC configuration also need to meet certain power constraint conditions, that is, the above equations are solvable.

[0112] For the configuration of the node reactor of the first voltage node set, in this embodiment, node screening is first performed based on the voltage margin threshold, that is, the nodes with are selected as the key over-limit nodes, and high-voltage reactors are configured; if there are no nodes with in the first voltage node set B1, then the absolute values of the voltage margins of all nodes need to be calculated and sorted in descending order, and then the key over-limit nodes corresponding to the larger second preset number of voltage margins are selected from the front of the sequence for high-voltage reactor configuration; the capacity of the high-voltage reactor configured in this embodiment is selected to meet , where is the rated voltage of the node, is the reactance of the power flow inflow line. Moreover, the second preset number can be selected according to the actual situation and is not limited here. For example, it is 5; completing the UPFC configuration of the branch and the high-voltage reactor configuration of the node realizes the preliminary configuration and obtains the preliminary configuration scheme.

[0113] Step 104: Calculate the branch power flow margin for the high-voltage power grid system configured according to the preliminary configuration scheme, and screen out the second control requirement set in combination with the branch power flow margin. The second control requirement set includes the second power flow line set and the second voltage node set.

[0114] Based on the preliminary configuration of the high-voltage power grid system according to the preliminary configuration scheme, power flow analysis can be performed again to screen out the new second control requirement set, and then more detailed configuration optimization processing can be carried out. The process of calculating the branch power flow margin is as follows:

[0115]

[0116] Among them, is the maximum value of the branch current, It is the branch power flow margin.

[0117] The lines with branch power flow margin less than the preset margin threshold are taken as the second power flow line set A2, and the nodes at both ends of the branches in the second power flow line set A2 are selected as the second voltage node set B2. The preset margin threshold in this embodiment is 20%, and it can also be configured as other values according to the actual situation. Here, it is only an example and not limited.

[0118] Step 105: Through the preset joint optimization configuration model, perform fine configuration and solution of UPFC and reactors for the lines and nodes in the second control requirement set to obtain the optimization configuration plan. The preset joint optimization configuration model includes power flow constraints and non-exceeding constraints.

[0119] Furthermore, step 105 includes:

[0120] Construct a joint optimization configuration objective function based on UPFC and reactors, and configure multiple constraint conditions for the joint optimization configuration objective function to generate the preset joint optimization configuration model. The constraint conditions include power flow constraints and non-exceeding constraints.

[0121] Based on the cuckoo search optimization algorithm, use the preset joint optimization configuration model to optimize and solve the UPFC configuration and reactor configuration plans in the second control requirement set to obtain the optimization configuration plan.

[0122] It should be noted that the joint optimization configuration objective function based on UPFC and reactors in this embodiment is expressed as:

[0123]

[0124] Among them, represents a variable with a value of 0 or 1. When the value is 0, it indicates that the i-th branch is not configured with UPFC; when the value is 1, it indicates that UPFC is configured; represents the number of groups of high-voltage reactors that need to be configured at the j-th node, and the value is an integer; is the construction cost of UPFC converted to an annual basis; is the annual operation and maintenance cost of UPFC; is the single-group capacity of the high-voltage reactor, with the unit of Mvar; is the investment and construction cost per unit capacity of the high-voltage reactor converted to an annual basis; is the annual operation and maintenance cost of a single high-voltage reactor. Among them, represents a variable with a value of 0 or 1:

[0125]

[0126] can be expressed as:

[0127]

[0128] Among them, is the total construction cost of a single unit / set of UPFC, represents the planned service life (years) of UPFC, represents the discount rate, which can take 0.1.

[0129] In this embodiment, the constraint conditions for the joint optimization configuration objective function are divided into two categories. One is the power flow constraint, and the other is the non-exceeding constraint. The power flow constraint is expressed as:

[0130]

[0131]

[0132]

[0133] Among them, and are the active and reactive powers of node i respectively, and represent the real and imaginary parts of the mutual admittance between nodes i and j respectively, represents the shunt conductance to the ground of the branch, represents the phase difference between nodes i and j.

[0134] The non-exceeding constraint is expressed as:

[0135]

[0136] Among them, represents the maximum allowable current value of branch ij, and represent the minimum and maximum allowable voltage values of node i respectively.

[0137] In this embodiment, based on the cuckoo search optimization algorithm, the preset joint optimization configuration model is optimized and solved, and an optimization configuration scheme based on the joint configuration of UPFC and high-voltage reactor can be obtained; for the specific solution process, please refer to Figure 9 . For the state variables and solved by the model; if , it indicates that a UPFC needs to be configured on the i-th branch; if , it means that no UPFC needs to be configured on the i-th branch; the power flow of this branch can be limited within the specified range through the joint adjustment of UPFC and high-voltage reactor on other branches. It represents the number of high-voltage reactors to be configured on the j-th node. It can be found that the combined configuration of UPFC and high-voltage reactors in the second stage is analyzed for all branches and nodes compared with the preliminary configuration in the first stage, rather than simply screening out several key over-limit objects for configuration. The hierarchical configuration methods in the two stages support and influence each other, so as to achieve a more flexible and reliable combined configuration.

[0138] The method for optimizing the configuration of UPFC and reactors in a high-voltage power grid provided by the embodiment of the present application constructs future typical scenarios of the power grid system according to the historical load data of the power grid, and then performs hierarchical optimization configuration of UPFC and reactors on the power flow over-limit branches and voltage over-limit nodes of the power grid system on this basis; the primary configuration is a rough configuration operation based on the power flow margin; then the preliminary configuration of the power grid system is completed based on the preliminary configuration plan; the re-configuration is to construct a preset combined optimization configuration model on the basis of the preliminary configuration, continuously optimize the configuration of UPFC and reactors of the line and node, and obtain the optimized configuration plan. This process fully considers the operation of the future urban high-voltage power grid system with more cables through two layers of progressive optimization configuration methods, can ensure the pertinence and effectiveness of the optimized configuration plan, and can meet the actual power grid configuration requirements. Therefore, the embodiment of the present application can solve the technical problem that the existing technology lacks an optimized configuration plan for UPFC and reactors in a multi-cable urban high-voltage power grid system, resulting in a lack of pertinence in actual configuration operations.

[0139] For ease of understanding, please refer to Figure 2 , the embodiment of the device for optimizing the configuration of UPFC and reactors in a high-voltage power grid provided by the present application includes:

[0140] A future scenario construction unit 201, configured to analyze the typical load data of the future scenario according to the historical load data of the power grid based on the variational mode decomposition method and the k-means clustering method, and construct a future typical scenario in combination with the future power grid architecture and equipment parameters;

[0141] A first power flow screening unit 202, configured to calculate the power flow margin by randomly selecting a scenario in the future typical scenario, and screen out a first control requirement set, where the first control requirement set includes a first power flow line set and a first voltage node set;

[0142] An over-limit rough configuration unit 203, configured to perform rough configuration of UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively according to the calculated power flow margin and branch power, and obtain a preliminary configuration plan;

[0143] The second power flow screening unit 204 is configured to calculate the branch power flow margin of the high-voltage power grid system configured according to the preliminary configuration scheme, and screen out the second control requirement set in combination with the branch power flow margin. The second control requirement set includes a second power flow line set and a second voltage node set;

[0144] The fine configuration unit 205 for modeling is configured to perform fine configuration and solution of UPFC and reactors on the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration scheme. The preset joint optimization configuration model includes power flow constraints and non-exceeding constraints.

[0145] Further, the future scenario construction unit 201 is specifically configured to:

[0146] Decompose the historical load data of the power grid into a main modal component and several sub-modal components based on the variational mode decomposition method;

[0147] Calculate the main modal component of the future load according to the preset growth rate and the main modal component to obtain the future main modal component;

[0148] Divide multiple basic load level values based on the future main modal component to obtain multiple future basic loads;

[0149] Superimpose several sub-modal components onto the future basic load to generate basic load data;

[0150] Use the k-means clustering method to perform clustering analysis according to the basic load data to obtain the typical load data of the future scenario;

[0151] Construct a future typical scenario in combination with the typical load data, the future power grid architecture, and equipment parameters.

[0152] Further, the first power flow screening unit 202 is specifically configured to:

[0153] Arbitrarily select a scenario in the future typical scenario to calculate the power flow margin, and obtain the branch power flow margin and the node voltage margin;

[0154] Screen all lines with a branch power flow margin less than 0 and all nodes with a node voltage margin less than 0 in the power grid system to generate a first control requirement set.

[0155] Further, the over-limit rough configuration unit 203 is specifically configured to:

[0156] Obtain the absolute value of the branch power flow margin and perform a descending order process, and select the first preset number of configured power flow margins in front of the generated margin sequence;

[0157] Based on the power constraint conditions generated by the branch power, determine the key over-limit lines according to the configured power flow margin and configure UPFC;

[0158] If there are nodes in the first voltage node set whose node voltage margins are less than the voltage margin threshold, key over-limit nodes are screened out according to the voltage margin threshold in the first voltage node set to configure reactors;

[0159] If there are no nodes in the first voltage node set whose node voltage margins are less than the voltage margin threshold, the node voltage margins of the second preset number with the largest absolute values are obtained as the configured voltage margins;

[0160] Key over-limit nodes are screened out according to the configured voltage margins in the first voltage node set to configure reactors, and a preliminary configuration plan is generated.

[0161] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical or other forms.

[0162] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0163] In addition, each functional unit in each embodiment of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0164] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (English full name: Read-Only Memory, English abbreviation: ROM), random access memories (English full name: Random Access Memory, English abbreviation: RAM), magnetic disks, or optical discs.

[0165] As described above, the above embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of various embodiments of this application.

Claims

1. Method for optimizing the configuration of UPFC and reactor in high-voltage power grid, characterized in that, Including: Analyze the typical load data of future scenarios based on the variational mode decomposition method and the k-means clustering method according to the historical load data of the power grid, and construct future typical scenarios by combining the future power grid architecture and equipment parameters; Arbitrarily select a scenario from the future typical scenarios to calculate the power flow margin, and screen out the first control requirement set, where the first control requirement set includes the first power flow line set and the first voltage node set; Roughly configure UPFCs and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively according to the calculated power flow margin and branch power, and obtain a preliminary configuration plan; Calculate the branch power flow margin of the high-voltage power grid system configured according to the preliminary configuration plan, and screen out the second control requirement set by combining the branch power flow margin. The second control requirement set includes the second power flow line set and the second voltage node set; Solve the refined configuration of UPFCs and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration plan. The preset joint optimization configuration model includes power flow constraints and non-overlimit constraints.

2. The method for optimizing the configuration of UPFC and reactor in a high-voltage power grid according to claim 1, characterized in that, The step of analyzing the typical load data of future scenarios based on the variational mode decomposition method and the k-means clustering method according to the historical load data of the power grid, and constructing future typical scenarios by combining the future power grid architecture and equipment parameters includes: Decompose the historical load data of the power grid into the main mode component and several sub-mode components based on the variational mode decomposition method; Calculate the main mode component of the future load according to the preset growth rate and the main mode component to obtain the future main mode component; Divide multiple basic load level values based on the future main mode component to obtain multiple future basic loads; Superimpose several of the sub-mode components onto the future basic load to generate basic load data; Use the k-means clustering method to perform clustering analysis according to the basic load data to obtain the typical load data of future scenarios; Construct future typical scenarios by combining the typical load data, future power grid architecture and equipment parameters.

3. The method for optimizing the configuration of UPFC and reactor in a high-voltage power grid according to claim 1, characterized in that, Before the step of analyzing the typical load data of future scenarios based on the variational mode decomposition method and the k-means clustering method according to the historical load data of the power grid, and constructing future typical scenarios by combining the future power grid architecture and equipment parameters, it also includes: Based on the current power grid architecture, combine the power grid planning information and the power source planning information to determine the architecture and equipment-related parameters of the future power grid system, and obtain the future power grid architecture and equipment parameters.

4. The method for optimizing the configuration of UPFC and reactor in a high-voltage power grid according to claim 1, wherein, The step of arbitrarily selecting a scenario from the future typical scenarios to calculate the power flow margin, and screening out the first control requirement set, where the first control requirement set includes the first power flow line set and the first voltage node set, includes: Arbitrarily select a scenario from the future typical scenarios to calculate the power flow margin to obtain the branch power flow margin and the node voltage margin; Screen all the lines in the power grid system where the branch power flow margin is less than 0, and all the nodes where the node voltage margin is less than 0 to generate the first control requirement set.

5. The method for optimizing the configuration of UPFC and reactor in a high-voltage power grid according to claim 4, wherein Coarsely configure UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively according to the calculated power flow margin and branch power, and obtain a preliminary configuration plan, including: After obtaining the absolute value of the branch power flow margin, perform a descending order process, and select the first preset number of configured power flow margins in front of the generated margin sequence; Based on the power constraint conditions generated by the branch power, determine the key over-limit lines from the first power flow line set according to the configured power flow margin, and configure UPFC; If there are nodes in the first voltage node set whose node voltage margin is less than the voltage margin threshold, screen the key over-limit nodes in the first voltage node set according to the voltage margin threshold and configure reactors; If there are no nodes in the first voltage node set whose node voltage margin is less than the voltage margin threshold, obtain the second preset number of the node voltage margins with the largest absolute value as the configured voltage margin; Screen the key over-limit nodes in the first voltage node set according to the configured voltage margin and configure reactors to generate a preliminary configuration plan.

6. The method for optimizing the configuration of UPFC and reactors in a high-voltage power grid according to claim 1, wherein Fine-configure and solve UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model to obtain an optimized configuration plan. The preset joint optimization configuration model includes power flow constraints and non-over-limit constraints, including: Construct a joint optimization configuration objective function based on UPFC and reactors, and configure multiple constraint conditions for the joint optimization configuration objective function to generate a preset joint optimization configuration model. The constraint conditions include power flow constraints and non-over-limit constraints; Based on the cuckoo search optimization algorithm, use the preset joint optimization configuration model to optimize and solve the UPFC configuration and reactor configuration plans in the second control requirement set to obtain an optimized configuration plan.

7. Optimized configuration device for UPFC and reactor in high-voltage power grid, characterized in that, Including: A future scenario construction unit for analyzing the typical load data of future scenarios based on variational mode decomposition and center clustering methods according to the historical load data of the power grid, and constructing future typical scenarios in combination with the future power grid architecture and equipment parameters; A first power flow screening unit for calculating the power flow margin in any one of the future typical scenarios and screening out a first control requirement set, where the first control requirement set includes a first power flow line set and a first voltage node set; An over-limit rough configuration unit for coarsely configuring UPFC and reactors for the key over-limit lines and nodes in the first power flow line set and the first voltage node set respectively according to the calculated power flow margin and branch power to obtain a preliminary configuration plan; A second power flow screening unit for calculating the branch power flow margin of the high-voltage power grid system configured according to the preliminary configuration plan, and screening out a second control requirement set in combination with the branch power flow margin. The second control requirement set includes a second power flow line set and a second voltage node set; The fine configuration unit for modeling is used to solve the fine configuration of UPFC and reactors for the lines and nodes in the second control requirement set through a preset joint optimization configuration model, and obtain an optimized configuration scheme. The preset joint optimization configuration model includes power flow constraints and non-exceeding constraints.

8. The UPFC and reactor optimal configuration device in a high-voltage power grid according to claim 7, characterized in that, The future scenario construction unit is specifically used for: Decomposing the historical load data of the power grid into a main modal component and several sub-modal components based on the variational mode decomposition method; Calculating the main modal component of the future load according to a preset growth rate and the main modal component to obtain the future main modal component; Dividing a plurality of basic load level values based on the future main modal component to obtain a plurality of future basic loads; Superimposing several of the sub-modal components onto the future basic load to generate basic load data; Performing clustering analysis on the basic load data by using the k-means clustering method to obtain the typical load data of the future scenario; Combining the typical load data, the future power grid architecture and equipment parameters to construct a future typical scenario.

9. The device for optimizing the configuration of UPFC and reactor in a high-voltage power grid according to claim 7, wherein, The first power flow screening unit is specifically used for: Arbitrarily selecting a scenario in the future typical scenario to calculate the power flow margin, and obtaining the branch power flow margin and the node voltage margin; Screening all lines with a branch power flow margin less than 0 and all nodes with a node voltage margin less than 0 in the power grid system to generate a first control requirement set.

10. The UPFC and reactor optimal configuration device in a high-voltage power grid according to claim 9, characterized in that, The rough configuration unit for over-limit is specifically used for: Obtaining the absolute value of the branch power flow margin and performing a descending order process, and selecting the first preset number of configured power flow margins in front of the generated margin sequence; Based on the power constraint conditions generated by the branch power, determining the key over-limit lines from the first power flow line set according to the configured power flow margin and configuring UPFC; If there are nodes with a node voltage margin less than the voltage margin threshold in the first voltage node set, screening the key over-limit nodes in the first voltage node set according to the voltage margin threshold to configure reactors; If there are no nodes with a node voltage margin less than the voltage margin threshold in the first voltage node set, obtaining the second preset number of node voltage margins with the largest absolute value as the configured voltage margin; Screening the key over-limit nodes in the first voltage node set according to the configured voltage margin to configure reactors, and generating a preliminary configuration scheme.

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