A flexible interconnection planning method for low voltage substations considering the power supply capacity of distribution network

Abstract

The present invention provides a method for planning low-voltage area flexible interconnection considering the power supply capacity of the distribution network, wherein the method includes obtaining the maximum power supply capacity of the distribution network under the actual load characteristics based on the actual distribution characteristics and growth law of the load, and using the obtained power supply capacity index to plan the installation location and capacity of the low-voltage area flexible interconnection device based on the NSGA-II multi-objective optimization algorithm. The present invention takes into account the characteristics of the network structure and the actual load to make the power supply capacity evaluation closer to reality. At the same time, the proposed low-voltage area flexible interconnection device site selection and capacity planning algorithm effectively improves the accuracy of the low-voltage area flexible interconnection planning, which has important practical significance for the transformation and construction of the distribution network flexible interconnection.

Description

Technical Field

[0001] The present invention belongs to the technical field of distribution network planning, and in particular relates to a low-voltage area flexible interconnection planning method taking into account the power supply capacity of the distribution network. Background Art

[0002] Total Supply Capability (TSC) is an important evaluation indicator in the distribution network, which means the maximum load that the distribution network can carry. Due to the current shortage of urban land resources, the construction scale of the distribution network is greatly restricted. Therefore, it is urgent to improve the utilization rate of distribution network transformers and line resources, eliminate power supply bottlenecks through reasonable connection planning, and make the load of the entire network more balanced. The construction of flexible interconnection devices can realize load transfer and capacity sharing without expanding the grid structure, tap the power supply potential of the distribution network, and realize the improvement of regional load carrying capacity. Based on the above considerations, in the planning process of flexible interconnection devices, it is more important to improve the power supply capacity of the distribution network than traditional indicators such as network loss.

[0003] The existing power supply capacity calculation methods can be mainly divided into two categories. One is the repeated power flow method using the AC power flow model, which iterates through the given load characteristics to obtain the upper limit of the load carrying capacity; the other is the linear programming method using the DC power flow model, which considers the capacity constraints of the main transformer, feeder and substation distribution transformer and the N-1 safety constraints to freely distribute the load. The former takes into account the actual load characteristics and power flow constraints, but the research on the power supply potential of the distribution network itself is insufficient. Although the margin of power supply can be calculated through indicators such as capacity-to-load ratio, considering the N-1 safety and other conditions, the capacity is not equal to the actual power supply upper limit; the latter fully considers the impact of network topology on the ideal load distribution, and takes into account the fault load transfer and other conditions, but its load distribution is too idealized, and it is often difficult to achieve in practice due to geographical location and other restrictions. Summary of the invention

[0004] The problem solved by the present invention is to address the shortcomings of existing power supply capacity evaluation methods and propose a low-voltage area flexible interconnection planning method that takes into account the power supply capacity of the distribution network, so as to solve the technical problem that it is difficult to take into account both the theoretical upper limit and the load characteristics in the current distribution network power supply capacity evaluation process. It can more reasonably evaluate the system power supply capacity when a low-voltage area flexible interconnection device is installed, and provide a reference for the planning and construction of the low-voltage area flexible interconnection device.

[0005] The present invention adopts the following technical solutions:

[0006] A method for planning low-voltage area flexible interconnection considering the power supply capacity of a distribution network comprises the following steps:

[0007] Generate a variable matrix representing the installation location and port capacity of the flexible interconnection device and the constraint conditions of the flexible interconnection device planning, and obtain a set of possible planning schemes for the flexible interconnection device; wherein the constraint conditions of the flexible interconnection device planning include the maximum installation quantity, the maximum installation capacity and the maximum port quantity;

[0008] The planning scheme for each flexible interconnection device is based on the capacity constraint of the distribution network equipment and the N-1 safety constraint criterion, and the maximum power supply capacity of the distribution network under the condition of free load distribution is obtained, which is called the theoretical TSC;

[0009] The planning scheme for each flexible interconnection device is based on the obtained maximum power supply capacity of the distribution network, based on the actual distribution characteristics and growth law of the load, to obtain the maximum power supply capacity of the distribution network under the actual load characteristics, which is called characteristic TSC; wherein, the current load of each substation is determined as the reference value, and the load is allowed to increase according to the iteration step length to represent the actual distribution characteristics and growth law of the load. By judging whether each iteration can meet the equipment capacity constraint and N-1 safety constraint under the current flexible interconnection planning scheme, when the constraint cannot be met, the iteration step length is halved until the maximum power supply capacity of the distribution network under the actual load characteristics is obtained through convergence;

[0010] Based on the obtained theoretical TSC and characteristic TSC, the generalized capacity ratio of the planning scheme of each flexible interconnection device is calculated;

[0011] Based on the possible planning schemes for flexible interconnected devices, the maximum characteristic TSC and the minimum generalized capacity-to-load ratio are used as objective functions to solve the optimal planning scheme for flexible interconnected devices, including the optimal installation location and capacity, and complete the flexible interconnection planning of low-voltage substations considering the power supply capacity of the distribution network.

[0012] Furthermore, the characteristic TSC is calculated as follows:

[0013] Determine the current load of each substation as the benchmark value, as well as the iteration step size and convergence accuracy of each substation;

[0014] Let the load grow according to the iteration step size, and determine whether the equipment capacity constraint and N-1 safety constraint can be met under the current flexible interconnection planning scheme; if the constraint cannot be met, halve the iteration step size;

[0015] Determine whether the convergence accuracy is achieved. If not, repeat the above steps. Otherwise, output the sum of all area loads as the maximum power supply capacity of the distribution network under the actual load characteristics.

[0016] Furthermore, the generalized capacity ratio The calculation method is as follows:

[0017]

[0018] in, is the theoretical TSC, Characteristic TSC.

[0019] Furthermore, the variable matrix representing the installation position and port capacity of the flexible interconnection device is as follows:

[0020]

[0021] Where: v is a 0-1 variable, representing whether the flexible interconnection device is connected to the corresponding area. 1 means that the area is connected to the flexible interconnection device, otherwise it is not. Represents the maximum number of flexible interconnection devices installed, n d Indicates the number of substations in the planning area.

[0022] Furthermore, the constraint of the maximum installation capacity is expressed as follows:

[0023]

[0024] in: Represents the maximum design capacity of the flexible interconnection device numbered r, and a capacity of 0 means that the flexible interconnection device is not installed.

[0025] Furthermore, the constraint on the maximum number of ports is expressed as follows:

[0026]

[0027] in: is a 0-1 variable, representing whether the flexible interconnection device numbered r is connected to the station area i; represents the number of ports designed for the flexible interconnect device numbered r, n d Indicates the number of substations in the planning area.

[0028] Furthermore, it also includes:

[0029] Taking the minimum installation cost of the flexible interconnection device as the objective function, the optimal planning scheme of the flexible interconnection device is optimized twice to obtain the final installation location and capacity configuration scheme of the flexible interconnection device.

[0030] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a method for planning flexible interconnection of low-voltage substations taking into account the power supply capacity of a distribution network is implemented.

[0031] A storage medium containing computer executable instructions, which, when executed by a computer processor, can implement a low-voltage area flexible interconnection planning method that takes into account the power supply capacity of a distribution network as described.

[0032] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the steps of a method for flexible interconnection planning of low-voltage substations taking into account the power supply capacity of a distribution network.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The power supply capacity evaluation method considering the load distribution characteristics of the distribution network, firstly, established a calculation model for the power supply capacity of the distribution network with iterative load growth, and proposed for the first time the evaluation index of the power supply capacity of the distribution network based on the actual load characteristics, which can effectively measure the rationality of the distribution network structure; and established a flexible interconnection equipment planning model considering the improvement of power supply capacity and economy, which effectively compensates for the shortcomings of the existing low-voltage flexible interconnection planning indicators and limited planning methods. This method can more comprehensively evaluate the impact of the installation scheme of low-voltage flexible interconnection devices on the power supply capacity of the system, which has important practical significance for the transformation and construction of flexible interconnection of distribution networks.

[0035] Furthermore, the characteristic TSC index takes into account the distribution characteristics and growth pattern of the actual load, and uses the port transmission characteristics of the flexible interconnection device in the substation area to transfer power between different substations, which facilitates the evaluation of the role of the flexible interconnection device in improving the power supply capacity of the distribution network.

[0036] Furthermore, the generalized capacity-to-load ratio indicator uses the theoretical TSC to give the upper limit of power supply capacity growth under a specific network structure, and uses a ratio to reflect the construction efficiency of the distribution network in flexible interconnection transformation under actual load conditions, which is convenient for evaluating the growth space of system power supply capacity under specific load conditions.

[0037] Furthermore, based on the characteristic TSC and generalized capacity-to-load ratio indicators, the installation location and capacity of the flexible interconnection device in the low-voltage substation area can be planned. The access location of flexible interconnection devices of any number and port number can be optimized, and the most economical result can be given through secondary optimization, helping technicians to form a reasonable installation plan for flexible interconnection devices.

[0038] In summary, the present invention takes into account the characteristics of the network structure and the actual load to make the power supply capacity evaluation closer to reality. At the same time, the proposed low-voltage substation flexible interconnection device site selection and capacity planning algorithm effectively improves the accuracy of low-voltage substation flexible interconnection planning and has good application prospects.

[0039] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flowchart of a low-voltage area flexible interconnection planning method considering the power supply capacity of the distribution network according to the present invention;

[0041] Figure 2 is a flowchart of calculating the characteristic TSC in an embodiment of the present invention;

[0042] Figure 3 This is a structural diagram of a distribution network flexible interconnection planning method in an embodiment of the present invention;

[0043] Figure 4 This is a diagram of a distribution network structure constructed based on the IEEE-14 node example in an embodiment of the present invention. 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 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 “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0046] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0047] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0048] The present invention analyzes the impact of load distribution and growth characteristics on the evaluation of the power supply capacity of the distribution network, and proposes a low-voltage area flexible interconnection planning method considering the power supply capacity of the distribution network. It can help evaluate the construction efficiency of the flexible interconnection transformation of the distribution network under actual load conditions and formulate the optimal installation plan for the flexible interconnection device.

[0049] The present invention provides a low voltage area flexible interconnection planning method considering the power supply capacity of the distribution network, such as Figure 1 As shown, the following steps are included:

[0050] S1. Generate a variable matrix representing the installation position and port capacity of the flexible interconnection device and the constraint conditions of the flexible interconnection device planning, and obtain a set of possible planning schemes for the flexible interconnection device; wherein the constraint conditions of the flexible interconnection device planning include the maximum installation quantity, the maximum installation capacity and the maximum port quantity; specifically, the following sub-steps are included:

[0051] S11, generating a variable matrix representing the installation position and port capacity of the flexible interconnection device;

[0052] The variable matrix is ​​shown in formula (1):

[0053]

[0054] in: is the number of substations in the planning area, v is a 0-1 variable, representing whether the flexible interconnection device is connected to the corresponding substation, 1 means that the substation is connected to the flexible interconnection device, otherwise it is not; represents the maximum number of flexible interconnection devices installed. Each row of the matrix represents a separate flexible interconnection device installation scheme. It represents the upper limit of the number of flexible interconnection devices that can be accepted in the plan. It is affected by factors such as cost and construction space, and does not represent the number of flexible interconnection devices that will be finally installed.

[0055] S12, generating constraint conditions for flexible interconnection device planning, including a maximum number of installations, a maximum installation capacity, and a maximum number of ports;

[0056] The maximum number of installations is already given by Limitation: Within the limit of the number of matrix rows, the number of flexible interconnection devices installed can be freely increased or decreased.

[0057] Limited by the technical level and construction space, the capacity constraint that the flexible interconnection device should meet is shown in formula (2):

[0058]

[0059] in: Represents the maximum design capacity of the flexible interconnection device numbered r. A capacity of 0 means that the flexible interconnection device is not installed.

[0060] The number of ports of the flexible interconnection device is constrained as shown in formula (3):

[0061]

[0062] in: is a 0-1 variable, representing whether the flexible interconnection device numbered r in equation (1) is connected to the station area i; Represents the number of ports designed for the flexible interconnect device numbered r.

[0063] S2. For each flexible interconnection device, based on the capacity constraint of the distribution network equipment and the N-1 safety constraint criterion, the maximum power supply capacity of the distribution network under the condition of free load distribution is obtained, which is called the theoretical TSC.

[0064] The calculation formula of theoretical TSC is shown in formula (4):

[0065]

[0066] in, is the total apparent power generated by users in area i.

[0067] The constraints that the area power and flexible interconnection device need to meet under normal operation are shown in formula (5):

[0068]

[0069] in: , and are the load powers on the distribution transformer in area i, feeder j and main transformer k respectively; , and They are the set of substation numbers belonging to feeder j, the set of feeder numbers belonging to main transformer k, and the set of all port numbers in a single flexible interconnection device; , , and They are the distribution transformer capacity of area i, the outlet capacity of feeder j, the capacity of main transformer k, and the port capacity of the flexible interconnection device connected to area i; is the power transmitted by the port of the flexible interconnection device connected to the station area i. A positive value represents the power absorbed by the port, and a negative value represents the power emitted by the port. is the net power absorbed by the flexible interconnect.

[0070] The constraints that the area power and flexible interconnection device need to meet when a certain component fails, that is, N-1 failure, are shown in formula (6):

[0071]

[0072] in: and They represent the substation number set under the new feeder j and the feeder number set under the main transformer k after network reconstruction under fault condition u respectively; Represents the power transmitted to the port of the flexible interconnection device connected to the substation i under fault condition u. In actual distribution network planning, when some important components fail, there is no corresponding dispatching scheme in the distribution network to meet the operation constraints, such as the power-off island formed by the distribution transformer failure in the substation. Such situations are not considered in the N-1 fault set.

[0073] S3. According to the maximum power supply capacity model of the distribution network obtained in step S2, based on the actual distribution characteristics and growth law of the load, the maximum power supply capacity of the distribution network under the actual load characteristics is obtained, which is called characteristic TSC; wherein, the current load of each substation is determined as the reference value, and the load is allowed to increase according to the iteration step length to represent the actual distribution characteristics and growth law of the load. By judging whether each iteration can meet the equipment capacity constraint and N-1 safety constraint under the current flexible interconnection planning scheme (obtained based on the variable matrix representing the installation location and port capacity of the flexible interconnection device), when the constraint cannot be met, the iteration step length is halved until the maximum power supply capacity of the distribution network under the actual load characteristics is obtained by convergence; please refer to Figure 2 , the specific steps are as follows:

[0074] S31. Determine the current load of each substation As the benchmark value, and the iteration step length of each station area and convergence accuracy;

[0075] S32, allowing the load to increase according to the iteration step length, and determining whether the device capacity constraint and the N-1 safety constraint can be met under the current flexible interconnection planning scheme; if the constraint cannot be met, halving the iteration step length;

[0076] The method for judging whether the equipment capacity constraint and the N-1 safety constraint can be met under the current flexible interconnection planning scheme is as follows: directly substitute the parameters under the current flexible interconnection planning scheme into equations (5) to (6) to judge whether they are met.

[0077] S33, determine whether the convergence accuracy is reached, if not, repeat the above steps, otherwise output the sum of all substation loads as the result.

[0078] S4, calculating the generalized capacity-loading ratio based on the theoretical TSC and characteristic TSC obtained in step S2 and step S3;

[0079] The calculation formula of generalized capacity-load ratio is shown in (7):

[0080]

[0081] in, is the generalized capacity ratio, is the theoretical TSC, Characteristic TSC.

[0082] S5. Based on the characteristic TSC obtained in step S3 and the generalized capacity-to-load ratio index obtained in step S4, the installation location and capacity of the low-voltage area flexible interconnection device are planned.

[0083] In a specific implementation scheme, the specific steps are as follows:

[0084] Taking the maximum characteristic TSC and the minimum generalized capacity-to-load ratio as the objective function, the optimal installation position and capacity of the flexible interconnection device are solved;

[0085] The solution model is shown in formula (8):

[0086]

[0087] Where: and Respectively represent the site selection plan and volume setting plan Characteristic TSC and generalized capacity ratio under; .

[0088] In a more preferred embodiment, the method further includes taking the minimum installation cost of the flexible interconnection device as the objective function, performing secondary optimization on the result obtained in the previous step, and obtaining the final installation location and capacity configuration scheme. The specific steps are as follows:

[0089] Taking the maximum characteristic TSC and the minimum generalized capacity-to-load ratio as the objective function, the optimal installation position and capacity of the flexible interconnection device are solved;

[0090] The quadratic optimization model is shown in formula (9):

[0091]

[0092] Where: Representative in site selection and volume setting plan The cost under this condition can be simplified to the sum of the capacities of all flexible interconnection devices when the flexible interconnection device installation type is single. and They represent the optimal solution sets of site selection and capacity planning obtained by solving the model of formula (8).

[0093] Among them, in the optimization process, optimization methods such as NSGA-II multi-objective optimization algorithm can be used to solve the problem. Figure 3The figure shows a flowchart of using the NSGA-II multi-objective optimization algorithm to solve the optimal installation location and capacity of the flexible interconnection device with the maximum characteristic TSC and the minimum generalized capacity-to-load ratio as the objective function, and a secondary optimization based on cost. In the figure, the population is first initialized as a set of possible planning schemes for flexible interconnection devices, and is fed back to the calculation module to calculate the theoretical TSC, the characteristic TSC and the generalized capacity-to-load ratio using the linear programming method for each scheme in turn, and the fitness function is calculated for the calculation results and then fed back to the optimization module for NSGA-II multi-objective optimization. The final result is subjected to secondary optimization based on cost to obtain the final optimal solution.

[0094] The effect of the present invention is further described below in conjunction with a specific embodiment:

[0095] like Figure 4 As shown in the figure, it is a distribution network constructed based on the IEEE-14 node example. Figure 4 The basic data of the distribution network is shown in Table 1:

[0096] Table 1 Network parameters

[0097]

[0098] The load base values ​​of the network are shown in Table 2:

[0099] Table 2 Load reference values

[0100]

[0101] The growth step length of the characteristic TSC solution of each substation is 0.05 times the load benchmark value. It is planned to install a maximum of 4 sets of two-port flexible interconnection devices, and the maximum capacity of the flexible interconnection device is 0.63 MV•A. The initial population size in the NSGA-II algorithm is 200, and the number of evolution generations is 200. According to Figure 3 The best installation solution calculated by the planning method is shown in Table 3:

[0102] Table 3 Best installation solution

[0103]

[0104] Using the power supply capacity evaluation method of the present invention, the distribution network before and after the installation of flexible interconnection is compared, and the results are shown in Table 4:

[0105] Table 4 Comparison of power supply capability indicators

[0106]

[0107] In addition, in order to highlight the effect of the solution of the present invention, this embodiment also sets two scenarios. Scenario 1 represents a single-objective flexible interconnection planning scheme using only the theoretical TSC as the objective function, and scenario 2 represents a multi-objective planning scheme using characteristic TSC and generalized capacity-to-load ratio. The power supply capacity indicators of the two are compared, and the results are shown in Table 5:

[0108] Table 5 Comparison of planning effects

[0109]

[0110] In summary, the present invention analyzes the impact of load distribution and growth characteristics on the evaluation of the power supply capacity of the distribution network, and proposes a low-voltage area flexible interconnection planning method considering the power supply capacity of the distribution network, which can help evaluate the construction efficiency of the flexible interconnection transformation of the distribution network under actual load conditions and formulate the optimal installation plan for the flexible interconnection device.

[0111] Corresponding to the aforementioned embodiment of a method for flexible interconnection planning of low-voltage substations taking into account the power supply capacity of the distribution network, the present invention also provides an electronic device, comprising one or more processors, for implementing a method for flexible interconnection planning of low-voltage substations taking into account the power supply capacity of the distribution network in the above embodiment.

[0112] The device embodiment can be implemented by software, hardware or a combination of software and hardware. Taking software implementation as an example, as a device in a logical sense, it is formed by the processor of any device with data processing capability in which it is located to read the corresponding computer program instructions in the non-volatile memory into the memory for execution. From the hardware level, it mainly includes a processor, memory, network interface, and non-volatile memory. In addition, any device with data processing capability in which the device in the embodiment is located can also include other hardware according to the actual function of the device with data processing capability, which will not be described in detail.

[0113] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0114] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of the present invention. Ordinary technicians in this field can understand and implement it without paying creative work.

[0115] An embodiment of the present invention also provides a computer-readable storage medium having a program stored thereon. When the program is executed by a processor, a low-voltage substation flexible interconnection planning method considering the power supply capacity of the distribution network in the above embodiment is implemented.

[0116] The computer-readable storage medium may be an internal storage unit of any device with data processing capability described in any of the aforementioned embodiments, such as a hard disk or a memory. The computer-readable storage medium may also be any device with data processing capability, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), an SD card, a flash card (Flash Card), etc. equipped on the device. Furthermore, the computer-readable storage medium may also include both an internal storage unit of any device with data processing capability and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by any device with data processing capability, and may also be used to temporarily store data that has been output or is to be output.

[0117] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for planning low-voltage area flexible interconnection considering the power supply capacity of the distribution network, characterized in that: The following steps are involved: Generate a variable matrix representing the installation location and port capacity of the flexible interconnection device and the constraint conditions of the flexible interconnection device planning, and obtain a set of possible planning schemes for the flexible interconnection device; wherein the constraint conditions of the flexible interconnection device planning include the maximum installation quantity, the maximum installation capacity and the maximum number of ports; The planning scheme for each flexible interconnection device is based on the capacity constraint of the distribution network equipment and the N-1 safety constraint criterion, and the maximum power supply capacity of the distribution network under the condition of free load distribution is obtained, which is called the theoretical TSC; The planning scheme for each flexible interconnection device is based on the obtained maximum power supply capacity of the distribution network, based on the actual distribution characteristics and growth law of the load, to obtain the maximum power supply capacity of the distribution network under the actual load characteristics, which is called characteristic TSC; wherein, the current load of each substation is determined as the reference value, and the load is allowed to increase according to the iteration step length to represent the actual distribution characteristics and growth law of the load. By judging whether each iteration can meet the equipment capacity constraint and N-1 safety constraint under the current flexible interconnection planning scheme, when the constraint cannot be met, the iteration step length is halved until the maximum power supply capacity of the distribution network under the actual load characteristics is obtained through convergence; Based on the theoretical TSC and characteristic TSC, the generalized capacity ratio of each flexible interconnection device is calculated; the generalized capacity ratio R g The calculation method is as follows: Among them, T th is the theoretical TSC, T ch It is a characteristic TSC; Based on a set of possible planning schemes for flexible interconnected devices, with the maximum characteristic TSC and the minimum generalized capacity-to-load ratio as the objective function, the optimal planning scheme for the flexible interconnected devices is solved, including the optimal installation location and capacity, to complete the flexible interconnection planning of low-voltage substations considering the power supply capacity of the distribution network.

2. The method according to claim 1, characterized in that The calculation method of characteristic TSC is as follows: Determine the current load S of each substation i As the benchmark value, as well as the iteration step length ΔS1 and convergence accuracy of each station area; Let the load grow according to the iterative step size, and determine whether the equipment capacity constraint and N-1 safety constraint can be met under the current flexible interconnection planning scheme; When the constraints cannot be met, the iteration step size is halved; Determine whether the convergence accuracy is achieved. If not, repeat the above steps. Otherwise, output the sum of all area loads as the maximum power supply capacity of the distribution network under the actual load characteristics.

3. The method according to claim 1, characterized in that The variable matrix representing the installation position and port capacity of the flexible interconnection device is as follows: Where: v is a 0-1 variable representing whether the flexible interconnection device is connected to the corresponding area. 1 means that the area is connected to the flexible interconnection device, otherwise it is not. n f Represents the maximum number of flexible interconnection devices installed, n d Indicates the number of substations in the planning area.

4. The method according to claim 1, characterized in that: The constraint of the maximum installation capacity is expressed as follows: 0≤c r ≤c rmax Where: c rmax Represents the maximum design capacity of the flexible interconnection device numbered r, and a capacity of 0 means that the flexible interconnection device is not installed.

5. The method according to claim 1, characterized in that: The constraint on the maximum number of ports is expressed as follows: Where: v ri is a 0-1 variable, representing whether the flexible interconnection device numbered r is connected to the station area i; represents the number of ports designed for the flexible interconnect device numbered r, n d Indicates the number of substations in the planning area.

6. The method according to claim 1, characterized in that Also includes: Taking the minimum installation cost of the flexible interconnection device as the objective function, the optimal planning scheme of the flexible interconnection device is optimized twice to obtain the final installation location and capacity configuration scheme of the flexible interconnection device.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements a low-voltage substation flexible interconnection planning method that takes into account the power supply capacity of the distribution network as described in any one of claims 1-6.

8. A storage medium comprising computer executable instructions, which, when executed by a computer processor, implement a method for planning flexible interconnection of low-voltage substations taking into account the power supply capacity of a distribution network as described in any one of claims 1 to 6.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of a method for flexible interconnection planning of low-voltage substations taking into account the power supply capacity of the distribution network as described in any one of claims 1-6 are implemented.

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