A method, system and device for evaluating the power supply capacity of an alternating current power distribution network after configuration of a flexible interconnection device, and a storage medium

Abstract

This invention discloses a method, system, device, and storage medium for evaluating the improvement of power supply capacity of an AC distribution network after the configuration of a flexible interconnection device, relating to the field of power grid technology. The method includes acquiring the output of each feeder in the AC distribution network during each detection period of a target detection cycle, where the target detection cycle includes a first detection cycle and a second detection cycle; determining the output difference of the feeders in the AC distribution network within the target detection cycle based on the output of each feeder during each detection period of the target detection cycle; determining the power supply capacity of the AC distribution network within the target detection cycle using the minimum output difference as the objective function; and determining and precisely quantifying the improvement in power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle, thereby improving the accuracy of the evaluation of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device.

Description

Technical Field

[0001] This invention relates to the field of power grid technology, and in particular to a method, system, device, and storage medium for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device. Background Technology

[0002] Uneven load distribution among feeders is one of the many limitations of traditional AC distribution networks. This uneven distribution leads to some lines being under heavy load or even overload for extended periods, severely impacting power supply reliability, while other lines are under light load, resulting in wasted resources. Against this backdrop, flexible distribution networks have emerged. Flexible interconnection devices enable flexible power exchange and distribution between different feeders, providing an effective means to balance loads and improve the power supply capacity of the distribution network.

[0003] The power supply capacity of AC distribution networks can be improved by using flexible interconnection devices. However, there is currently no effective solution to quantify and evaluate the degree of improvement in power supply capacity after configuring flexible interconnection devices. Therefore, there is an urgent need for a solution to quantify the degree of improvement in power supply capacity of AC distribution networks after configuring flexible interconnection devices. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to solve the problem of inaccurate assessment of the improvement in the power supply capacity of AC distribution network before and after configuring flexible interconnection device.

[0005] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes a method, system, device and storage medium for evaluating the improvement of AC power supply capacity after the configuration of flexible interconnection devices, which includes a method for evaluating the improvement of AC power supply capacity after the configuration of flexible interconnection devices, a system for evaluating the improvement of AC power supply capacity after the configuration of flexible interconnection devices, a computer device and a computer-readable storage medium.

[0006] In a first aspect, the present invention proposes a method for evaluating the improvement in the power supply capacity of an AC distribution network after the configuration of a flexible interconnection device, which includes, S1. Obtain the output of each feeder in the AC distribution network during each detection period of the target detection cycle. The target detection cycle includes a first detection cycle and a second detection cycle. The first detection cycle and the second detection cycle are the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The target detection cycle includes at least one detection period. S2. Determine the output difference of feeders in the AC distribution network within the target detection period based on the output of each feeder during each detection period of the target detection cycle; S3. Using the minimum output difference within the target detection period as the objective function, determine the power supply capacity of the AC distribution network within the target detection period; S4. Based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle, determine the power supply capacity improvement value of the AC distribution network before and after the configuration of the flexible interconnection device.

[0007] In a preferred embodiment of the AC distribution network power supply capacity improvement assessment method after the flexible interconnection device configuration of the present invention: the specific steps for obtaining the output of each feeder in the AC distribution network during each detection period of the target detection cycle are as follows. Obtain the power supply node of each feeder in the AC distribution network; For each feeder, obtain the power output of the feeder's power node during each detection period of the target detection cycle; The output of the power node of the feeder in each detection period of the target detection cycle is determined as the output of the feeder in each detection period of the target detection cycle.

[0008] In a preferred embodiment of the AC distribution network power supply capacity improvement assessment method after the flexible interconnection device configuration of the present invention: the step of determining the output difference of feeders in the AC distribution network within the target detection period based on the output of each feeder in each detection time period of the target detection period is as follows. Determine the average output value of each feeder within each testing period; The output difference of feeders in the AC distribution network during the target detection period is determined based on the output and average value of each feeder during each detection period of the target detection cycle.

[0009] In a preferred embodiment of the AC distribution network power supply capacity improvement assessment method after the flexible interconnection device configuration of the present invention: the step of determining the output difference of feeders in the AC distribution network within the target detection period based on the output and average value of each feeder in each detection period of the target detection period is as follows. Based on the output and average value of each feeder in each detection period of the target detection cycle, determine the output difference of each feeder in each detection period of the target detection cycle; The output difference of each feeder in the AC distribution network during the target detection period is calculated by integral summation.

[0010] In a preferred embodiment of the AC distribution network power supply capacity improvement evaluation method after the flexible interconnection device configuration of the present invention: the specific steps for determining the AC distribution network power supply capacity within the target detection period, with the objective function being the minimum output difference within the target detection period, are as follows. The power flow of the AC distribution network within the target detection period is determined with the objective function of minimizing the output difference within the target detection period. The power supply capacity of the AC distribution network during the target detection period is determined based on the power flow of the AC distribution network during the target detection period.

[0011] In a preferred embodiment of the AC distribution network power supply capacity improvement assessment method after the flexible interconnection device configuration of the present invention: the power flow includes the output of each feeder within the target detection cycle; The objective function for determining the power flow of the AC distribution network within the target detection period is to minimize the output difference within that period. The specific steps are as follows: With the objective function of minimizing the output difference within the target detection period, the maximum output of the power node of each feeder in the AC distribution network during each detection period of the target detection period is determined as the output of each feeder within the target detection period. The specific steps for determining the power supply capacity of the AC distribution network within the target detection period, based on the power flow of the AC distribution network during the target detection period, are as follows. The power supply capacity of the AC distribution network during the target testing period is determined based on the rated output of each feeder and the maximum output of each feeder during the target testing period.

[0012] In a preferred embodiment of the AC distribution network power supply capacity improvement assessment method after the flexible interconnection device configuration of the present invention: the power flow of the AC distribution network during the target detection period must at least satisfy the following constraints. When the first node is the end node of a branch, the sum of the active power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of the active power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. When the first node is the end node of a branch, the sum of reactive power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of reactive power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. In the AC distribution network, during each detection period of the target detection cycle, the voltage at each node on each feeder is within the preset voltage range; In the AC distribution network, during each detection period of the target detection cycle, the current on each branch of each feeder is within the preset current range; In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission on each branch of each feeder is less than the first threshold. In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission of the power station on each feeder is less than the second threshold. In the AC distribution network, during each detection period of the target detection cycle, the actual output of each feeder to the strain gauge station is less than the predicted output of the feeder to the strain gauge station. After the AC distribution network is equipped with flexible interconnection devices, the active power of each port of the flexible interconnection device, the loss of the flexible interconnection device, and the DC output power of each port of the flexible interconnection device meet the first preset condition. After the AC distribution network is equipped with flexible interconnection devices, the active power and reactive power of the flexible interconnection devices in each detection period meet the second preset condition with respect to the rated capacity of the flexible interconnection devices. After the AC distribution network is equipped with flexible interconnection devices, the sum of the DC side output power of each port of the flexible interconnection device is 0 during each detection period.

[0013] Secondly, this invention proposes an evaluation system for improving the power supply capacity of an AC distribution network after the configuration of a flexible interconnection device, comprising: The acquisition module is used to acquire the output of each feeder in the AC distribution network during each detection period of the target detection cycle. The target detection cycle includes a first detection cycle and a second detection cycle, which are the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The target detection cycle includes at least one detection period. The determination module is used to determine the output difference of feeders in the AC distribution network within the target detection cycle based on the output of each feeder in each detection period of the target detection cycle; The determining module is also used to determine the power supply capacity of the AC distribution network within the target detection period, with the objective function being to minimize the output difference within the target detection period; The determining module is further configured to determine the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle.

[0014] Thirdly, the present invention proposes a computer device, including a memory, a processor, and computer-executable instructions stored in the memory, wherein the processor is used to execute the computer-executable instructions to implement the steps of the evaluation method for improving the power supply capacity of the AC distribution network after the flexible interconnection device is configured.

[0015] Fourthly, the present invention proposes a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the evaluation method for improving the power supply capacity of the AC distribution network after the flexible interconnection device is configured.

[0016] The beneficial effects of this invention are as follows: By obtaining the output of each feeder in the AC distribution network during each detection period of the corresponding detection cycle before and after the configuration of the flexible interconnection device, the output difference of the feeders in the AC distribution network within the corresponding detection cycle is determined. Then, with the minimum output difference within the corresponding detection cycle as the objective function, the power supply capacity of the AC distribution network within the corresponding detection cycle is determined. Furthermore, based on the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device can be determined. In this way, by using the minimum output difference within the corresponding detection cycle as the objective function to quantitatively determine the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, the accuracy of the assessment of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device is improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A flowchart is shown, illustrating the evaluation method for improving the power supply capacity of AC distribution networks after the configuration of flexible interconnection devices. Figure 2 A schematic diagram of an assessment system for improving the power supply capacity of an AC distribution network after the configuration of a flexible interconnection device is shown. Figure 3 A schematic diagram of a computer device is shown. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0020] The terminology used in the embodiments of this invention will be explained below.

[0021] AC distribution network: refers to the power network system that transmits electrical energy from high-voltage transmission networks or distributed power sources to various users (households, businesses, and industries) safely and reliably through voltage reduction and distribution.

[0022] Flexible interconnection of AC distribution networks refers to the use of advanced power electronic equipment (such as inverters and converters) to precisely and flexibly control the direction and magnitude of power flow between or within traditional AC distribution networks, much like "smart valves," thereby greatly improving the controllability, flexibility, and energy efficiency of the power grid.

[0023] Rigid interconnection of AC distribution networks: This typically involves connecting two distribution networks (such as lines from different substations) using conventional transformers or simple switches. Electricity, like water, naturally flows from areas of high voltage to areas of low voltage. Traditional transformers cannot flexibly regulate this flow, resulting in some lines being overloaded while adjacent lines have spare capacity.

[0024] Soft Open Point (SOP): This is a more specific application of flexible interconnection in distribution networks. It usually replaces the traditional normally open tie switch to realize flexible interconnection between feeders (lines).

[0025] Power flow: Voltage, electricity, and power during steady-state operation of a power grid. In other words, power flow is the steady-state distribution of voltage (at each node) and power (active and reactive power) (at each branch) in a power system.

[0026] Feeder: Also called power distribution line or feeder line, it refers to the whole consisting of all power lines, towers, cables, switchgear, etc. that start from the low-voltage side bus of the power distribution substation and transmit and distribute electrical energy to a specific area.

[0027] In an embodiment of the present invention, the AC distribution network has multiple feeders, each feeder has multiple nodes, the line between two adjacent nodes is called a branch, the first node of each feeder is connected to a substation, and the output at the first node is the interactive output between the substation at that node and the feeder, which is the output of the feeder.

[0028] Power supply capacity: The proportion of power supply capacity that is idle under the current load level of the feeder.

[0029] Reference Figure 1 This embodiment provides a method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device, including the following steps: S1. Obtain the output of each feeder in the AC distribution network during each detection period of the target detection cycle.

[0030] Specifically, the target detection cycle includes a first detection cycle and a second detection cycle. The first and second detection cycles correspond to the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The duration of the first and second detection cycles is the same. For example, taking a detection cycle of 1 day as an example, where the first detection cycle is the detection cycle corresponding to the AC distribution network before the flexible interconnection device is configured, and the second detection cycle is the detection cycle corresponding to the AC distribution network after the flexible interconnection device is configured, the first detection cycle can be 1 day before the selected AC distribution network is configured, and the second detection cycle can be 1 day after the selected AC distribution network is configured. For example, if the AC distribution network is configured with a flexible interconnection device on September 15, 2025, then the first detection cycle can be September 13, 2025, and the second detection cycle can be September 17, 2025.

[0031] It should be noted that in the following embodiments, the first detection cycle is the detection cycle corresponding to the AC distribution network before the flexible interconnection device is configured, and the second detection cycle is the detection cycle corresponding to the AC distribution network after the flexible interconnection device is configured, as examples for illustration.

[0032] The detection period can be the period in the target detection cycle used to detect the output of each feeder in the AC distribution network. In this embodiment of the invention, both the first detection cycle and the second detection cycle can be divided into multiple detection periods. That is, the target detection cycle can include at least one detection period, and the number of detection periods included in the first detection cycle and the number of detection periods included in the second detection cycle are the same. For example, if the detection period is 1 hour, there are 24 detection periods in the first detection cycle and 24 detection periods in the second detection cycle.

[0033] In an embodiment of the present invention, the specific steps for obtaining the output of each feeder in the AC distribution network during each detection period of the target detection cycle are as follows: Obtain the power supply node of each feeder in the AC distribution network; For each feeder, obtain the power output of the feeder's power node during each detection period of the target detection cycle; The output of the power node of the feeder in each detection period of the target detection cycle is determined as the output of the feeder in each detection period of the target detection cycle.

[0034] Specifically, a power supply node can be the power supply node corresponding to each feeder in the AC distribution network. This power supply node can be the first node of each feeder, i.e., the node connected to the substation. The power supply node of each feeder in the AC distribution network can be obtained. Then, for each feeder, the output of the power supply node in each detection period of the first detection cycle and the output in each detection period of the second detection cycle can be obtained. The output of the power supply node in each detection period of the first detection cycle is then determined as the output of the feeder in each detection period of the first detection cycle, and the output of the power supply node in each detection period of the second detection cycle is also determined as the output of the feeder in each detection period of the second detection cycle.

[0035] Taking an AC distribution network equipped with a flexible interconnection device on September 15, 2025, with the first testing period on September 13, 2025, and the second testing period on September 17, 2025, and a testing period of 1 hour, and assuming the flexible interconnection device has three feeders (feeder 1, feeder 2, and feeder 3), from 0:00 to 24:00 on September 13, 2025, the output of the power node of feeder 1 in the AC distribution network was acquired every hour, and the output of feeder 1 acquired every hour was taken as the output of feeder 1 during that period. Similarly, from 0:00 to 24:00 on September 13, 2025, the output of feeder 2 in the AC distribution network was acquired every hour, and the output of feeder 2 acquired every hour was taken as the output of feeder 2 during that period. From 0:00 to 24:00 on September 13, 2025, the output of the power node of feeder 3 in the AC distribution network will be acquired every hour, and the output of the power node of feeder 3 acquired every hour will be used as the output of feeder 3 during that period.

[0036] Correspondingly, from 00:00 to 24:00 on September 17, 2025, the output of the power node of feeder 1 in the AC distribution network will be acquired every hour, and the hourly output of feeder 1 will be used as the output of feeder 1 during that period. Similarly, from 00:00 to 24:00 on September 17, 2025, the output of the power node of feeder 2 in the AC distribution network will be acquired every hour, and the hourly output of feeder 2 will be used as the output of feeder 2 during that period. From 00:00 to 24:00 on September 17, 2025, the output of feeder 3 in the AC distribution network will be acquired every hour, and the hourly output of feeder 3 will be used as the output of feeder 3 during that period.

[0037] For each feeder, the output of the feeder's power node during each detection period of the target detection cycle is determined as the feeder's output during each detection period of the target detection cycle. This allows for the quantification of the feeder's output during each detection period of the target detection cycle, providing effective data support for the subsequent quantitative evaluation of power supply capacity improvement.

[0038] S2. Determine the output difference of feeders in the AC distribution network during the target detection period based on the output of each feeder during each detection period of the target detection cycle.

[0039] Specifically, the output difference can be the difference in output of all feeders involved in the AC distribution network during the target detection period. The output difference of feeders in the AC distribution network during the target detection period can be determined based on the output of each feeder during each detection period of the target detection period.

[0040] In an embodiment of the present invention, the specific steps for determining the output difference of feeders in the AC distribution network within the target detection period based on the output of each feeder within each detection time period of the target detection period are as follows: Determine the average output value of each feeder within each testing period; The output difference of feeders in the AC distribution network during the target detection period is determined based on the output and average value of each feeder during each detection period of the target detection cycle.

[0041] Specifically, for each detection period, the average output of each feeder can be determined. That is, for the first detection cycle, the average output of each feeder in each detection period of the first detection cycle can be determined, and for the second detection cycle, the average output of each feeder in each detection period of the second detection cycle can be determined.

[0042] By determining the average output of each feeder during each testing period, and then based on the output and average value of each feeder during each testing period of the target testing cycle, the output difference of feeders in the AC distribution network during the target testing cycle can be quantitatively determined.

[0043] For the first testing cycle, the average output of each feeder within each testing period of the first testing cycle can be determined first. Then, based on the output of each feeder within each testing period of the first testing cycle, and the average output of each feeder within that testing period, the output difference of the feeders in the AC distribution network within the first testing cycle can be determined. Continuing with the example above, on September 13, 2025, the average output of feeder 1, feeder 2, and feeder 3 at 0:00 (hereinafter referred to as average value 1), the average output of feeder 1, feeder 2, and feeder 3 at 1:00 (hereinafter referred to as average value 1), and the average output of feeder 1, feeder 2, and feeder 3 from 2:00 to 24:00 (hereinafter referred to as average value 1) can be determined first. Then, based on the output of feeder 1 at 0 o'clock and its average value 1 at 0 o'clock, and based on the output of feeder 2 at 0 o'clock and its average value 1 at 0 o'clock, and based on the output of feeder 3 at 0 o'clock and its average value 1 at 0 o'clock, and based on the output of feeder 1 at 1 o'clock on September 13, 2025 and its average value 1 at 1 o'clock, and based on the output of feeder 2 at 1 o'clock and its average value 1 at 1 o'clock, and based on the output of feeder 3 at 1 o'clock and its average value 1 at 1 o'clock (and so on), the output difference of feeders in the AC distribution network on September 13, 2025 is determined.

[0044] Correspondingly, for the second detection cycle, the calculation method of the first detection cycle can be used as a reference to calculate the output difference of the feeders in the AC distribution network on September 17, 2025.

[0045] In an embodiment of the present invention, the specific steps for determining the output difference of feeders in the AC distribution network within the target detection period based on the output and average value of each feeder in each detection time period of the target detection period are as follows: Based on the output and average value of each feeder in each detection period of the target detection cycle, determine the output difference of each feeder in each detection period of the target detection cycle; The output difference of each feeder in the AC distribution network during the target detection period is calculated by integral summation.

[0046] Specifically, the output difference of a feeder in each detection period of the first detection cycle can be determined based on the output of each feeder in each detection period of the first detection cycle and the average output of each feeder in each detection period of the first detection cycle.

[0047] After calculating the output difference of each feeder in each detection period of the first detection cycle, the output difference of each feeder in each detection period of the first detection cycle can be integrated and summed to obtain the output difference of the feeders in the AC distribution network in the first detection cycle.

[0048] Correspondingly, the output difference of each feeder in each detection period of the second detection cycle can be determined based on the output of each feeder in each detection period of the second detection cycle and the average output of each feeder in each detection period of the first detection cycle.

[0049] After calculating the output difference of each feeder in each detection period of the second detection cycle, the output difference of each feeder in each detection period of the second detection cycle can be integrated and summed to obtain the output difference of the feeders in the AC distribution network in the second detection cycle.

[0050] The output difference of feeders in an AC distribution network during the target detection period can be determined according to the following formula (1): (1) in, For each feeder, there is a set of power nodes. For the target detection cycle, In order to be within the target detection cycle Power nodes during testing period The output of the feeder at the location, In order to be within the target detection cycle The average output of each feeder during the testing period.

[0051] By determining the output difference of each feeder in each detection period of the target detection cycle based on the output of each feeder in each detection period of the target detection cycle, and the average output of each feeder in each detection period of the target detection cycle, the output difference of each feeder in each detection period of the target detection cycle can be integrated and summed to obtain the output difference of the feeders in the AC distribution network in the target detection cycle. In this way, the output difference of the feeders in the AC distribution network in the target detection cycle can be quantitatively determined.

[0052] S3. Using the minimum output difference within the target detection period as the objective function, determine the power supply capacity of the AC distribution network within the target detection period.

[0053] In an embodiment of the present invention, the specific steps for determining the power supply capacity of the AC distribution network within the target detection period, using the minimum output difference as the objective function, are as follows: The power flow of the AC distribution network within the target detection period is determined with the objective function of minimizing the output difference within the target detection period. The power supply capacity of the AC distribution network during the target detection period is determined based on the power flow of the AC distribution network during the target detection period.

[0054] In an embodiment of the present invention, the power flow includes the output of each feeder during the target detection cycle; The objective function for determining the power flow of the AC distribution network within the target detection period is to minimize the output difference within that period. The specific steps are as follows: With the objective function of minimizing the output difference within the target detection period, the maximum output of each power node of each feeder in the AC distribution network during each detection period of the target detection period is determined as the output of each feeder within the target detection period.

[0055] Specifically, when determining the output of each feeder within the target detection period, the first step is to obtain the output of the power node of each feeder in the AC distribution network during each detection period of the target detection period, with the objective function being to minimize the output difference within the target detection period. Then, the maximum output value is selected from the output of the power node of each feeder during each detection period of the target detection period, and this maximum value is taken as the output of that feeder within the target detection period. This avoids the situation where the average or minimum output of the power node of each feeder during each detection period of the target detection period is taken as the output of that feeder within the target detection period, which could lead to some feeders having outputs greater than the output of that feeder during certain detection periods within the target detection period, causing damage to the AC distribution network and thus affecting its operation.

[0056] Using the following formula (2) as the objective function, the power flow of the AC distribution network during the target detection period can be determined under the condition that formula (2) is satisfied: (2) The meanings of the parameters in formula (2) are the same as those in formula (1) above.

[0057] In an embodiment of the present invention, the specific steps for determining the power supply capacity of the AC distribution network within the target detection period based on the power flow of the AC distribution network within the target detection period are as follows: The power supply capacity of the AC distribution network during the target testing period is determined based on the rated output of each feeder and the maximum output of each feeder during the target testing period.

[0058] Specifically, the output of each feeder during the target detection period can be obtained first, with the objective function being to minimize the output difference within the target detection period. Then, based on the maximum output of each feeder and its rated output, the power supply capacity of the AC distribution network during the target detection period can be obtained, as shown in the following formula (3): (3) in, This refers to the power supply capacity of the AC distribution network during the target detection period. For feeder set, For the feeder during the target detection cycle Rated output, To minimize the output difference within the target detection cycle, from each feeder... The maximum output value selected from the outputs within the target detection cycle.

[0059] In embodiments of the present invention, the power flow of the AC distribution network during the target detection period shall at least satisfy the following constraints. When the first node is the end node of a branch, the sum of the active power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of the active power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. When the first node is the end node of a branch, the sum of reactive power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of reactive power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. In the AC distribution network, during each detection period of the target detection cycle, the voltage at each node on each feeder is within the preset voltage range; In the AC distribution network, during each detection period of the target detection cycle, the current on each branch of each feeder is within the preset current range; In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission on each branch of each feeder is less than the first threshold. In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission of the power station on each feeder is less than the second threshold. In the AC distribution network, during each detection period of the target detection cycle, the actual output of each feeder to the strain gauge station is less than the predicted output of the feeder to the strain gauge station. After the AC distribution network is equipped with flexible interconnection devices, the active power of each port of the flexible interconnection device, the loss of the flexible interconnection device, and the DC output power of each port of the flexible interconnection device meet the first preset condition. After the AC distribution network is equipped with flexible interconnection devices, the active power and reactive power of the flexible interconnection devices in each detection period meet the second preset condition with respect to the rated capacity of the flexible interconnection devices. After the AC distribution network is equipped with flexible interconnection devices, the sum of the DC side output power of each port of the flexible interconnection device is 0 during each detection period.

[0060] Specifically, the first node can be any node on a branch of the feeder.

[0061] The preset voltage range can be a pre-set voltage range for each node. The value of the preset voltage range can be set by the user according to their needs, and is not limited in this embodiment of the invention.

[0062] It should be noted that the preset voltage range corresponding to each node on each feeder can be the same or different. The specific range can be set according to the user's needs, and is not limited in this embodiment of the invention.

[0063] The preset current range can be the current range of each branch that is set in advance. The value of the preset current range can be set by the user according to their needs, and is not limited in this embodiment of the invention.

[0064] It should be noted that the preset current range corresponding to each branch on each feeder can be the same or different. The specific range can be set according to the user's needs, and is not limited in this embodiment of the invention.

[0065] The first threshold can be a pre-set threshold for the L2 norm of the active power and reactive power transmission of each branch in each detection period of the target detection cycle in the AC distribution network. The value of the first threshold can be set by the user according to their needs, and is not limited in this embodiment of the invention.

[0066] It should be noted that the first threshold corresponding to each branch on each feeder can be the same or different. The specific threshold can be set according to the user's needs, and is not limited in this embodiment of the invention.

[0067] The second threshold can be a pre-set threshold for the L2 norm of the active power transmission and reactive power transmission of the strain relief substation on each feeder during each detection period of the target detection cycle in the AC distribution network. The value of the second threshold can be set by the user according to their needs, and is not limited in this embodiment of the invention.

[0068] It should be noted that the second threshold corresponding to each feeder can be the same or different, and can be set according to user needs. This invention does not impose any limitations on this.

[0069] The first preset condition can be a pre-set condition that the active power of each port of the flexible interconnection device, the loss of the flexible interconnection device, and the DC output power of each port of the flexible interconnection device are satisfied after the AC distribution network is configured with the flexible interconnection device.

[0070] The second preset condition can be that after the AC distribution network is equipped with flexible interconnection devices, the active power and reactive power of the flexible interconnection devices in each detection period meet the conditions of the rated capacity of the flexible interconnection devices.

[0071] When the first node is the end node of a branch, the sum of the active power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period during each detection period is the same as the sum of the active power of the first node and the branch between the first node and the end node of the same branch in the target detection period during each detection period when the first node is the beginning node of a branch, as shown in the following formula (4): (4) in, For nodes The set of the first nodes of the branches of the terminal node (i.e., As the first node, in the first node When the first node is the terminal node of a branch, it can be considered as the terminal node of a branch. The first nodes of all branches of the terminal node are grouped together. ), For nodes The set of branch end nodes of the first node (i.e., the set of branch end nodes of the first node). In the case of the first node of a branch, the first node can be used as the starting node. The set of end nodes in all branches of the first end node is grouped together. ), In order to be in the testing period Inner slave node To the node The active power of the branch circuit, For testing period From node Flow to Node The branch current, For nodes To the node The branch resistance, In order to be in the testing period Inner slave node To the node The active power of the branch circuit. In order to be in the testing period internal nodes The active power at the location.

[0072] When the first node is the end node of a branch, the sum of reactive power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period during each detection period is the same as the sum of reactive power of the first node and the branch between the first node and the end node of the same branch in the target detection period during each detection period when the first node is the beginning node of a branch, as shown in the following formula (5): (5) in, For testing period From node To the node The reactive power of the branch circuit, For nodes To the node The impedance of the branch, , In order to be in the testing period Inner slave node To the node The reactive power of the branch circuit. In order to be in the testing period internal nodes The reactive power at the location.

[0073] In an AC distribution network, the voltage at each node on each feeder during each detection period of the target detection cycle can be determined according to the following formula (6): (6) in, For testing period node Voltage amplitude at that point For testing period node The voltage amplitude at the point is the same as that in formula (4) and formula (5) above.

[0074] In an AC distribution network, during each detection period of the target detection cycle, the current on each branch of each feeder can be determined according to the following formula (7): (7) The parameters in formula (7) have the same meaning as those in formulas (4), (5) and (6) above.

[0075] In the AC distribution network, during each detection period of the target detection cycle, the voltage at each node on each feeder is within the preset voltage range, as shown in the following formula (8): (8) in, and They are nodes The upper and lower limits of the voltage at that location.

[0076] In the AC distribution network, during each detection period of the target detection cycle, the current on each branch of each feeder is within the preset current range, as shown in the following formula (9): (9) in, and They are slave nodes To the node The upper and lower limits of the current in the branch circuit.

[0077] In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power and reactive power transmitted on each branch of each feeder is less than the first threshold, as shown in the following formula (10): (10) in, It is a norm 2. For the line The upper limit of power transmission, i.e. This is the first threshold.

[0078] In the AC distribution network, during the target detection period, the L2 norm of the active power transmission and reactive power transmission of the substation on each feeder is less than the second threshold, as shown in the following formula (11): (11) in, For substation During the testing period Active transmission power within, For substation During the testing period Reactive power transmission within the system For substation The upper limit of power transmission, i.e. This is the second threshold.

[0079] In the AC distribution network, during the target detection period, the actual output of the strain gauge on each feeder is less than the predicted output of the strain gauge on the feeder, as shown in the following formula (12): (12) in, For substation During the testing period The actual output of the internal force For substation During the testing period Predicted output within ( The value can be predicted by a third party, and is not limited in this embodiment of the invention.

[0080] After the AC distribution network is equipped with flexible interconnection devices, the active power of each port of the flexible interconnection device, the loss of the flexible interconnection device, and the DC output power of each port of the flexible interconnection device meet the first preset condition, as shown in the following formula (13): (13) in, For flexible interconnect devices port During the detection period of the target detection cycle Active power within, For flexible interconnect devices port During the testing period DC-side output power inside, For flexible interconnect devices Loss during the target detection cycle.

[0081] After the AC distribution network is equipped with flexible interconnection devices, the active power and reactive power of the flexible interconnection devices in each detection period meet the second preset condition with respect to the rated capacity of the flexible interconnection devices, as shown in the following formula (14): (14) in, For flexible interconnect devices During the detection period of the target detection cycle Active power within, For flexible interconnect devices During the detection period of the target detection cycle Reactive power within, For flexible interconnect devices The quota capacity.

[0082] After the AC distribution network is equipped with flexible interconnection devices, the sum of the DC side output power of each port of the flexible interconnection devices is 0 during each detection period, as shown in the following formula (15): (15) in, For flexible interconnect devices A collection of all ports.

[0083] S4. Based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle, determine the power supply capacity improvement value of the AC distribution network before and after the configuration of the flexible interconnection device.

[0084] Specifically, the power supply capacity of the AC distribution network in the first detection period and the power supply capacity in the second detection period can be obtained according to the above formula (3). Then, the difference between the power supply capacity of the AC distribution network in the second detection period and the power supply capacity in the first detection period is used as the power supply capacity improvement value of the AC distribution network before and after the flexible interconnection device is configured. In this way, the power supply capacity improvement value of the AC distribution network before and after the flexible interconnection device is configured can be quantitatively calculated.

[0085] It should be noted that the above formula (2) contains an absolute value function. The absolute value function itself is nonlinear, but it can be linearized by introducing additional variables and constraints. One common method is to use an intermediate variable and add two constraints. That is, the above formula (2) can be transformed into the following formula (16): (16) in, As an intermediate variable, the meanings of the other parameters in formula (16) are the same as those in formula (2) above.

[0086] The two additional constraints that need to be added are shown in the following formula (17): (17) The meaning of the parameters in formula (17) is the same as that in formula (2) and formula (16) above.

[0087] Formula (7) above contains a quadratic term, which is a nonlinear programming problem. Therefore, it can be solved using the cone optimization algorithm. The standard form of the cone optimization model is shown in formula (18) below: (18) in, As decision variables, ,and It is a quadratic cone. , and It is a constant.

[0088] By utilizing second-order cone relaxation, the nonlinear model of the above formula (7) is transformed into a standard second-order cone programming problem that can be solved efficiently. First, two variables are introduced. and As shown in the following formula (19): (19) The meaning of the parameters in formula (19) is the same as that in formula (7) above.

[0089] By further processing formula (7) using the above formulas (8) and (9), it can be written in the form of a standard second-order cone, as shown in the following formula (20): (20) The meaning of the parameters in formula (20) is the same as that in formulas (7), (8), (9) and (19) above.

[0090] Then, the above formula (16) is solved. During the solution process, the power flow of the AC distribution network must meet all the constraints mentioned above. The optimal power flow with the minimum output difference within the target detection period as the objective function can be obtained. Then, the power supply capacity of the AC distribution network within the target detection period can be obtained based on the optimal power flow.

[0091] Reference Figure 2 This embodiment also provides an evaluation system for improving the power supply capacity of AC distribution networks after the configuration of flexible interconnection devices, including: The acquisition module is used to acquire the output of each feeder in the AC distribution network during each detection period of the target detection cycle. The target detection cycle includes a first detection cycle and a second detection cycle, which are the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The target detection cycle includes at least one detection period. The determination module is used to determine the output difference of feeders in the AC distribution network within the target detection cycle based on the output of each feeder in each detection period of the target detection cycle; The determining module is also used to determine the power supply capacity of the AC distribution network within the target detection period, with the objective function being to minimize the output difference within the target detection period; The determining module is further configured to determine the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle.

[0092] Reference Figure 3This embodiment also provides a computer device applicable to the assessment method for improving the power supply capacity of AC distribution networks after the configuration of flexible interconnection devices. The computer device includes a processor, a memory, a communication interface, and a bus. The processor, memory, and communication interface are connected via the bus and communicate with each other. The memory stores computer-executable instructions, and the processor executes these instructions to implement the assessment method for improving the power supply capacity of AC distribution networks after the configuration of flexible interconnection devices as proposed in the above embodiment.

[0093] The computer device can also be a terminal, including a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0094] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the AC power distribution network power supply capacity improvement assessment method proposed in the above embodiments after the flexible interconnection device is configured. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0095] In summary, this invention determines the output difference of each feeder in the AC distribution network within each detection period of the corresponding detection cycle before and after the configuration of the flexible interconnection device. Then, using the minimum output difference within the corresponding detection cycle as the objective function, the power supply capacity of the AC distribution network within the corresponding detection cycle is determined. Furthermore, based on the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device can be determined. In this way, by using the minimum output difference within the corresponding detection cycle as the objective function to quantitatively determine the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, the accuracy of the assessment of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device is improved.

[0096] Finally, it should be noted that the methods, systems, devices, and storage media described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A method for evaluating the improvement in AC distribution network power supply capacity after the configuration of a flexible interconnection device, characterized in that: include, S1. Obtain the output of each feeder in the AC distribution network during each detection period of the target detection cycle. The target detection cycle includes a first detection cycle and a second detection cycle. The first detection cycle and the second detection cycle are the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The target detection cycle includes at least one detection period. S2. Determine the output difference of feeders in the AC distribution network within the target detection period based on the output of each feeder during each detection period of the target detection cycle; S3. Using the minimum output difference within the target detection period as the objective function, determine the power supply capacity of the AC distribution network within the target detection period; S4. Based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle, determine the power supply capacity improvement value of the AC distribution network before and after the configuration of the flexible interconnection device.

2. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 1, characterized in that: The specific steps for obtaining the output of each feeder in the AC distribution network during each detection period of the target detection cycle are as follows. Obtain the power supply node of each feeder in the AC distribution network; For each feeder, obtain the power output of the feeder's power node during each detection period of the target detection cycle; The output of the power node of the feeder in each detection period of the target detection cycle is determined as the output of the feeder in each detection period of the target detection cycle.

3. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 1, characterized in that: The method for determining the output difference of feeders in the AC distribution network within the target detection cycle based on the output of each feeder during each detection period of the target detection cycle involves the following specific steps. Determine the average output value of each feeder within each testing period; The output difference of feeders in the AC distribution network during the target detection period is determined based on the output and average value of each feeder during each detection period of the target detection cycle.

4. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 3, characterized in that: The method for determining the output difference of feeders in the AC distribution network within the target detection period based on the output and average value of each feeder in each detection period of the target detection period is as follows: Based on the output and average value of each feeder in each detection period of the target detection cycle, determine the output difference of each feeder in each detection period of the target detection cycle; The output difference of each feeder in the AC distribution network during the target detection period is calculated by integral summation.

5. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 1, characterized in that: The method for determining the power supply capacity of the AC distribution network within the target detection period, with the objective function being the minimum output difference, involves the following specific steps. The power flow of the AC distribution network within the target detection period is determined with the objective function of minimizing the output difference within the target detection period. The power supply capacity of the AC distribution network during the target detection period is determined based on the power flow of the AC distribution network during the target detection period.

6. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 5, characterized in that: The power flow includes the output of each feeder during the target detection cycle; The objective function for determining the power flow of the AC distribution network within the target detection period is to minimize the output difference within that period. The specific steps are as follows: With the objective function of minimizing the output difference within the target detection period, the maximum output of the power node of each feeder in the AC distribution network during each detection period of the target detection period is determined as the output of each feeder within the target detection period. The specific steps for determining the power supply capacity of the AC distribution network within the target detection period, based on the power flow of the AC distribution network during the target detection period, are as follows. The power supply capacity of the AC distribution network during the target testing period is determined based on the rated output of each feeder and the maximum output of each feeder during the target testing period.

7. The method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device according to claim 6, characterized in that: The power flow of the AC distribution network during the target detection period must at least satisfy the following constraints. When the first node is the end node of a branch, the sum of the active power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of the active power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. When the first node is the end node of a branch, the sum of reactive power of the first node and the branch between the first node and the beginning node of the same branch in the target detection period is the same as the sum of reactive power of the first node and the branch between the first node and the end node of the same branch in the target detection period when the first node is the beginning node of a branch. In the AC distribution network, during each detection period of the target detection cycle, the voltage at each node on each feeder is within the preset voltage range; In the AC distribution network, during each detection period of the target detection cycle, the current on each branch of each feeder is within the preset current range; In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission on each branch of each feeder is less than the first threshold. In the AC distribution network, during each detection period of the target detection cycle, the L2 norm of the active power transmission and reactive power transmission of the power station on each feeder is less than the second threshold. In the AC distribution network, during each detection period of the target detection cycle, the actual output of each feeder to the strain gauge station is less than the predicted output of the feeder to the strain gauge station. After the AC distribution network is equipped with flexible interconnection devices, the active power of each port of the flexible interconnection device, the loss of the flexible interconnection device, and the DC output power of each port of the flexible interconnection device meet the first preset condition. After the AC distribution network is equipped with flexible interconnection devices, the active power and reactive power of the flexible interconnection devices in each detection period meet the second preset condition with respect to the rated capacity of the flexible interconnection devices. After the AC distribution network is equipped with flexible interconnection devices, the sum of the DC side output power of each port of the flexible interconnection device is 0 during each detection period.

8. A system for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device, based on the method for evaluating the improvement of AC distribution network power supply capacity after the configuration of a flexible interconnection device as described in any one of claims 1-7, characterized in that: include, The acquisition module is used to acquire the output of each feeder in the AC distribution network during each detection period of the target detection cycle. The target detection cycle includes a first detection cycle and a second detection cycle, which are the detection cycles of the AC distribution network before and after the flexible interconnection device is configured, respectively. The target detection cycle includes at least one detection period. The determination module is used to determine the output difference of feeders in the AC distribution network within the target detection cycle based on the output of each feeder in each detection period of the target detection cycle; The determining module is also used to determine the power supply capacity of the AC distribution network within the target detection period, with the objective function being to minimize the output difference within the target detection period; The determining module is further configured to determine the improvement value of the power supply capacity of the AC distribution network before and after the configuration of the flexible interconnection device, based on the power supply capacity of the AC distribution network in the first detection cycle and the power supply capacity in the second detection cycle.

9. A computer device, comprising a memory, a processor, and computer-executable instructions stored in the memory, characterized in that: The processor is configured to execute computer-executable instructions to implement the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by the processor, it implements the steps of the method described in any one of claims 1-7.

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