Feeder flexible interconnection planning method and device based on self-consistent distribution unit

Abstract

The present disclosure provides a kind of based on self-consistent distribution unit area flexible interconnection planning method and planning device, including obtaining uncontrollable data of area, based on the uncontrollable data of area, calculate uncontrollable net load of area, the uncontrollable data includes the uncontrollable distributed power generation of area and the rigid load power of area;Based on the uncontrollable net load of area, calculate the complementary matching degree of area in distribution network;The self-consistent distribution unit of the two areas under the highest complementary matching degree of area is selected to plan, the objective function and constraint condition of self-consistent distribution unit are constructed;The objective function is solved, and the planning result is output.The present disclosure can guarantee the safe and economic operation of distribution network, and as far as possible to absorb new energy generation by the above method.

Description

Technical Field

[0001] This invention relates to the field of flexible interconnection planning for distribution transformer areas, and specifically to a planning method and device for flexible interconnection planning of distribution transformer areas based on self-consistent distribution units. Background Technology

[0002] As a hub connecting users and the main power grid, the distribution network will face the integration of large-scale distributed power sources, electric vehicles, energy storage and other low-carbon elements. This will lead to problems such as insufficient system carrying capacity, unbalanced load and voltage exceeding limits, posing a severe challenge to the planning and operation of the distribution network.

[0003] The power system is currently at a critical juncture in its energy transition. The ongoing development of distributed generation technologies is not well-suited to the current centralized large-scale power grid structure. Microgrids, while supporting active distribution networks, are relatively independent. For power systems with high renewable energy penetration, some scholars have proposed the concept of cellular grids. In this future, the power system will consist of multiple cells, with blurred boundaries between generation, transmission, and distribution. A cell is a flexible combination of distributed generators, energy storage units, and loads interconnected within a certain power or geographical boundary. A new distribution network structure is needed that leverages the economies of scale of centralized structures while improving power supply capacity to cope with extreme events through distributed generation. Simultaneously, demand response needs to be decentralized to distribution substations to encourage user participation and provide fundamental guarantees for user-side demand response from a grid structure perspective. Summary of the Invention

[0004] The purpose of this invention is to provide a planning method and device for flexible interconnection of distribution substations based on self-consistent distribution units, so as to ensure the safe and economical operation of the distribution network and to absorb new energy power generation as much as possible.

[0005] According to one aspect of this disclosure, a method for flexible interconnection planning of distribution substations based on self-consistent distribution units is provided, comprising: acquiring uncontrollable data of the distribution substations; calculating the uncontrollable net load of the distribution substations based on the uncontrollable data, wherein the uncontrollable data includes the uncontrollable distributed generation power and the rigid load power of the distribution substations; calculating the complementarity matching degree of the distribution substations in the distribution network based on the uncontrollable net load of the distribution substations; selecting self-consistent distribution units under the two distribution substations with the highest complementarity matching degree for planning, constructing the objective function and constraints of the self-consistent distribution units; solving the objective function, and outputting the planning results.

[0006] According to some embodiments of this disclosure, the objective function is solved to output the planning result, specifically including: solving the objective function to obtain the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit and the benefit obj after the self-consistent distribution unit; setting a critical value; if the benefit obj is greater than the set critical value, the complementary matching degree between each pair of distribution units in the remaining distribution units is recalculated, and the two distribution units with the highest complementary matching degree are selected for replanning; if obj is less than the critical value, the planning ends, the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit is planned according to the original calculation results, and the planning result is output.

[0007] According to some embodiments of this disclosure, in the step of acquiring uncontrollable data of a transformer area and calculating the uncontrollable net load of the transformer area based on the uncontrollable data, the uncontrollable net load is: In the formula, P i,t For the uncontrollable net load of transformer area i; Let t be the rigid load power of the transformer area at time t; Let t be the uncontrollable distributed generation power of the distribution area at time t, where t = 1, 2, ..., T, and T is the number of time periods in a day. The time step is 1 hour, and T is 24.

[0008] According to some embodiments of this disclosure, the calculation of the complementary matching degree of transformer substations in the distribution network includes calculating the longitudinal complementary matching degree and the lateral complementary matching degree of transformer substations, and the formula is: C ij =ΔC ij ·δC ij

[0009] In the formula, C ij For the complementary matching degree of the transformer area; ΔC ij For the vertical complementarity matching degree of the transformer area; δC ij The degree of horizontal complementarity matching between the two regions.

[0010] According to some embodiments of this disclosure, the longitudinal complementary matching degree of the transformer substations is the ratio of the average to the maximum value of the uncontrollable net load difference between substation i and substation j at each time point. It reflects the overall smoothness of the new load curve after the uncontrollable net load curves of the two substations are superimposed, and is expressed by the formula:

[0011]

[0012] Where: δC ij This refers to the overall smoothness of the curve.

[0013] According to some embodiments of this disclosure, the horizontal complementary matching degree of the transformer substations is the ratio of the minimum to the maximum sum of the uncontrollable net loads of substation i and substation j at each time point, reflecting the overall smoothness of the new load curve after the superposition of the uncontrollable net load curves of the two substations. The formula is expressed as:

[0014]

[0015] Where: δC ij This refers to the overall smoothness of the curve.

[0016] According to some embodiments of this disclosure, the self-consistent distribution units under the two distribution areas with the highest complementary matching degree are selected for planning, and an objective function for the self-consistent distribution unit is constructed. The planning variables are the capacity of controllable distributed generation and the energy storage capacity in the self-consistent distribution unit. It is assumed that the planned capacities of energy storage and controllable distributed generation in the self-consistent distribution unit under distribution area i are respectively... and

[0017] The objective function of this plan can then be expressed as:

[0018]

[0019] In the formula: obj represents the benefit after installing a self-consistent power distribution unit; α t and β t γ represents the unit energy loss cost coefficients for the AC and DC systems at time t, respectively; t k is the unit capacity compensation cost coefficient for flexible loads participating in demand response in a self-consistent distribution unit at time t. BS and are energy storage and k, respectively. CG Investment coefficient per unit capacity for controllable distributed generation; t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour, and T is 24. This represents the change in AC network losses. This represents the change in DC network losses. This represents the change in flexible load; The planned energy storage capacity in a self-consistent power distribution unit; This refers to the planned capacity of controllable distributed generation in a self-consistent distribution unit.

[0020] According to some embodiments of this disclosure, the constraints include: for any unit area i, the following power balance constraints are satisfied, specifically:

[0021]

[0022] In the formula: and These are the rigid load and flexible load power at time t, respectively, both of which can be obtained through load prediction. and These are the outputs of uncontrollable distributed generation and controllable distributed generation at time t, respectively. The former can be predicted by new energy power generation, while the latter is a control variable. Let t be the power of interaction between the energy storage and the self-consistent power distribution unit. Energy storage charging is a positive value, and vice versa. Let t be the power exchanged between the self-consistent power distribution unit and the outside world at time t. The outflow is positive and the outflow is negative. t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour. The value of T is 24.

[0023] According to some embodiments of this disclosure, the constraints include the requirement that the device must satisfy the following constraints during operation:

[0024]

[0025] In the formula, and These represent the lower limit and rated capacity of uncontrollable distributed generation output under transformer area i, respectively. and These are the lower limit and rated capacity of controllable distributed generation output under transformer area i, respectively.

[0026]

[0027] In the formula, The rated energy storage capacity to be planned in the self-consistent distribution unit under the i-type substation.

[0028] According to another aspect of this disclosure, a flexible interconnection planning device for distribution transformer areas based on self-consistent distribution units is provided, comprising: a data acquisition module for acquiring uncontrollable data of the distribution transformer area and calculating the uncontrollable net load of the distribution transformer area based on the uncontrollable data, wherein the uncontrollable data includes the uncontrollable distributed generation power and the rigid load power of the distribution transformer area; a data matching module for calculating the complementarity matching degree of the distribution transformer areas in the distribution network based on the uncontrollable net load of the distribution transformer area; a model building module for selecting the self-consistent distribution units under the two distribution transformer areas with the highest complementarity matching degree for planning, and constructing the objective function and constraints of the self-consistent distribution units; and a planning output module for solving the objective function and outputting the planning result.

[0029] As can be seen from the above technical solution, this disclosure proposes a planning method and device for flexible interconnection of distribution substations based on self-consistent distribution units. It constructs a novel self-consistent distribution unit that organically integrates flexible loads, controllable distributed generation, and energy storage, enabling it to effectively participate in grid demand response with fully controllable overall external characteristics. Furthermore, this unit can be retrofitted using existing switchgear without significant additional investment, requiring no additional site selection and saving land. It effectively decentralizes demand response to the low-voltage side of the distribution substations, providing the basic conditions for large-scale participation of small and medium-sized users in demand response. It fully considers the substation matching degree in the entire distribution network, performing flexible DC interconnection on the low-voltage side for substations with good matching. Based on optimal AC / DC substation load transfer, a self-consistent distribution unit is obtained. Attached Figure Description

[0030] Figure 1 A flowchart of the planning method for flexible interconnection of distribution substations based on self-consistent distribution units, according to this disclosure, is presented. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] Exemplary methods

[0034] This disclosure provides a method for planning flexible interconnection of distribution transformer areas based on self-consistent distribution units, which specifically includes the following steps:

[0035] S110, acquire uncontrollable data of the transformer area, calculate the uncontrollable net load of the transformer area based on the uncontrollable data of the transformer area, the uncontrollable data includes the uncontrollable distributed generation power of the transformer area and the rigid load power of the transformer area;

[0036] First, the uncontrollable net load of a typical daytime substation area i is calculated.

[0037] in, Let be the rigid load power of the transformer area at time t. Let t be the uncontrollable distributed generation power of the distribution area at time t, where t = 1, 2, ..., T, and T is the number of time periods in a day. The time step is 1 hour, and T is 24.

[0038] S120, Calculate the complementary matching degree of the distribution network based on the uncontrollable net load of the distribution area;

[0039] The complementary matching degree of the transformer area is calculated using the uncontrollable net load of the transformer area. The complementary matching degree of the transformer area is composed of the longitudinal complementary matching degree and the lateral complementary matching degree of the transformer area.

[0040] The longitudinal complementarity matching degree of transformer substations is defined as the ratio of the average to the maximum value of the uncontrollable net load difference between substation i and substation j at each time point. It reflects the overall smoothness of the new load curve after the uncontrollable net load curves of the two substations are superimposed. Its calculation formula is:

[0041]

[0042] In the formula: P i,t P represents the uncontrollable net load of transformer area i; j,t The uncontrollable net load of area j.

[0043] The horizontal complementarity matching degree of transformer substations is defined as the ratio of the minimum to the maximum sum of the uncontrollable net loads of substations i and j at each time point. It reflects the overall smoothness of the new load curve after the uncontrollable net load curves of the two substations are superimposed. Its calculation formula is:

[0044]

[0045] In the formula, δC ij This refers to the overall smoothness of the curve.

[0046] The longitudinal and transverse complementary matching degrees of distribution areas are combined using a cumulative multiplication method to form the complementary matching degree of the distribution area containing self-consistent distribution units. Assuming the maximum value of each indicator is 1, the formula for calculating the complementary matching degree C between distribution area i and distribution area j is:

[0047] C ij =ΔC ij ·δCij

[0048] In the formula, C ij For the complementary matching degree of the transformer area; ΔC ij For the vertical complementarity matching degree of the transformer area; δC ij The degree of horizontal complementarity matching between the two regions.

[0049] S130, select the self-consistent distribution units under the two distribution areas with the highest complementary matching degree for planning, and construct the objective function and constraints of the self-consistent distribution units;

[0050] The complementarity matching degree between two distribution areas in the entire distribution network is used to select the self-consistent distribution units under the two distribution areas with the highest complementarity matching degree for planning. The planning variables are the capacity of controllable distributed generation and energy storage capacity in the self-consistent distribution units.

[0051] (1) The objective of this open planning problem is:

[0052] Maximize the loss reduction cost in the network, minimize the compensation cost of flexible loads participating in demand response in self-consistent distribution units, and minimize the investment cost of energy storage and controllable distributed generation in self-consistent distribution units.

[0053] Assume that the active power of transformer area i interacting with the power grid at time t is The loss reduction of the AC network is a function of the power exchange between each distribution area and the power grid, specifically expressed as:

[0054]

[0055] In the formula: P i,t P represents the uncontrollable net load of transformer area i; j,t The uncontrollable net load of area j.

[0056] Similarly, suppose that the active power of a self-consistent distribution unit under transformer area i interacting with other self-consistent distribution units at time t is... The DC network loss reduction is a function of the interactive power between the respective distribution units, specifically expressed as:

[0057]

[0058] Meanwhile, assuming at time t during operation, the flexible loads in the self-consistent distribution unit under transformer area i have Participate in demand response.

[0059] Assume that the planned capacities of energy storage and controllable distributed generation in the self-consistent distribution unit under transformer area i are respectively and

[0060] The objective function of this planning problem can then be expressed as:

[0061]

[0062] Where: obj represents the benefits after installing the self-consistent power distribution unit; α t and β t γ represents the unit energy loss cost coefficients for the AC and DC systems at time t, respectively; t k is the unit capacity compensation cost coefficient for flexible loads participating in demand response in a self-consistent distribution unit at time t. BS and k BS These are the unit capacity investment coefficients for energy storage and controllable distributed generation, respectively. t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour, and T is 24.

[0063] (2) The constraints of this planning problem are as follows:

[0064] 1) For any given region i, the following power balance constraints must be satisfied.

[0065]

[0066] in: and These are the rigid load and flexible load power at time t, respectively, both of which can be obtained through load prediction. and These are the outputs of uncontrollable distributed generation and controllable distributed generation at time t, respectively. The former can be predicted by new energy power generation, while the latter is a control variable. Let t be the power of interaction between the energy storage and the self-consistent power distribution unit. Energy storage charging is a positive value, and vice versa. Let t be the power exchanged between the self-consistent power distribution unit and the outside world at time t. The outflow is positive and the outflow is negative. t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour. The value of T is 24. This represents the change in AC network losses. This represents the change in DC network losses. This represents the change in flexible load; The planned energy storage capacity in a self-consistent power distribution unit; This refers to the planned capacity of controllable distributed generation in a self-consistent distribution unit.

[0067] 2) The following constraints must be met during equipment operation:

[0068]

[0069] in: and These represent the lower limit and rated capacity of uncontrollable distributed generation output under transformer area i, respectively. and These represent the lower limit and rated capacity of controllable distributed generation output under substation i, respectively.

[0070]

[0071] in: The rated energy storage capacity to be planned in the self-consistent distribution unit under the i-type substation.

[0072] S140, Solve the objective function and output the planning result.

[0073] Solving the above planning problem yields the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit, as well as the benefit obj after installing the self-consistent distribution unit. If obj is greater than a certain critical value ε, the complementarity matching degree between each pair of distribution units is recalculated in the remaining distribution units. The two distribution units with the highest complementarity matching degree are selected, and the process returns to step S120 for planning. If obj is less than the critical value ε, the planning ends. The rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit is planned according to the previous calculation results. Then, the planning results are output, and the planning process ends.

[0074] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0075] Exemplary device

[0076] The flexible interconnection planning device for transformer substations based on self-consistent distribution units according to embodiments of this disclosure includes:

[0077] The data acquisition module is used to acquire uncontrollable data of the distribution area and calculate the uncontrollable net load of the distribution area based on the uncontrollable data. The uncontrollable data includes the uncontrollable distributed generation power and the rigid load power of the distribution area. The data matching module is used to calculate the complementarity matching degree of the distribution areas in the distribution network based on the uncontrollable net load of the distribution area. The model building module is used to select the self-consistent distribution units under the two distribution areas with the highest complementarity matching degree for planning and construct the objective function and constraints of the self-consistent distribution units. The planning output module is used to solve the objective function and output the planning results.

[0078] In one example, to obtain uncontrollable data for a transformer area and calculate the uncontrollable net load of that area based on that data, the uncontrollable net load of transformer area i on a typical day is first calculated. in, Let be the rigid load power of the transformer area at time t. Let t be the uncontrollable distributed generation power of the distribution area at time t, where t = 1, 2, ..., T, and T is the number of time periods in a day. The time step is 1 hour, and T is 24.

[0079] In one example, the objective function is solved, and the planning results are output, specifically including:

[0080] Solving the objective function yields the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit, as well as the benefit obj after implementing the self-consistent distribution unit. A critical value is set. If the benefit obj is greater than the set critical value, the complementary matching degree between each pair of distribution units in the remaining distribution units is recalculated, and the two distribution units with the highest complementary matching degree are selected for replanning. If obj is less than the critical value, the planning ends, and the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit is planned according to the original calculation results. The planning results are then output.

[0081] In one example, the calculation of the complementary matching degree of transformer substations in the distribution network includes calculating the longitudinal complementary matching degree and the lateral complementary matching degree of transformer substations, and the formula is as follows:

[0082] C ij =ΔC ij ·δC ij

[0083] In the formula, C ij For the complementary matching degree of the transformer area; ΔC ij For the vertical complementarity matching degree of the transformer area; δC ij The degree of horizontal complementarity matching between the two regions.

[0084] In one example, the longitudinal complementarity matching degree of the transformer substations is the ratio of the average to the maximum value of the uncontrollable net load difference between substation i and substation j at each time point. It reflects the overall smoothness of the new load curve after the uncontrollable net load curves of the two substations are superimposed. The formula is expressed as:

[0085]

[0086] In the formula: P i,t P represents the uncontrollable net load of transformer area i; j,t The uncontrollable net load of area j.

[0087] In one example, the horizontal complementarity matching degree of the transformer substations is the ratio of the minimum to the maximum sum of the uncontrollable net loads of substation i and substation j at each time point. It reflects the overall smoothness of the new load curve after the uncontrollable net load curves of the two substations are superimposed. The formula is expressed as:

[0088]

[0089] Where: δC ij This refers to the overall smoothness of the curve.

[0090] In one example, the self-consistent distribution units under the two distribution areas with the highest complementary matching degree are selected for planning. An objective function for the self-consistent distribution unit is constructed, with the planning variables being the capacity of controllable distributed generation and the energy storage capacity within the self-consistent distribution unit. It is assumed that the planned capacities of energy storage and controllable distributed generation in the self-consistent distribution unit under distribution area i are respectively... and

[0091] The objective function of this plan can then be expressed as:

[0092]

[0093] In the formula: obj represents the benefit after installing a self-consistent power distribution unit; α t and β t γ represents the unit energy loss cost coefficients for the AC and DC systems at time t, respectively; t k is the unit capacity compensation cost coefficient for flexible loads participating in demand response in a self-consistent distribution unit at time t. BS and k CG These are the unit capacity investment coefficients for energy storage and controllable distributed generation, respectively; t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour, and T is 24. This represents the change in AC network losses. This represents the change in DC network losses. This represents the change in flexible load; The planned energy storage capacity in a self-consistent power distribution unit; This refers to the planned capacity of controllable distributed generation in a self-consistent distribution unit.

[0094] The constraints include:

[0095] For any given region i, the following power balance constraints are satisfied:

[0096]

[0097] In the formula: and These are the rigid load and flexible load power at time t, respectively, both of which can be obtained through load prediction. and These are the outputs of uncontrollable distributed generation and controllable distributed generation at time t, respectively. The former can be predicted by new energy power generation, while the latter is a control variable. Let t be the power of interaction between the energy storage and the self-consistent power distribution unit. Energy storage charging is a positive value, and vice versa. Let t be the power exchanged between the self-consistent power distribution unit and the external environment. Outflow is positive, and outflow is negative. t = 1, 2, ..., T, where T is the number of time periods in a day, with a time step of 1 hour, and T is 24.

[0098] The following constraints must be met during equipment operation:

[0099]

[0100] In the formula, and These represent the lower limit and rated capacity of uncontrollable distributed generation output under transformer area i, respectively. and These are the lower limit and rated capacity of controllable distributed generation output under transformer area i, respectively.

[0101]

[0102] In the formula, The rated energy storage capacity to be planned in the self-consistent distribution unit under the i-type substation.

[0103] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (ROM), flash memory, erasable read-only memory (EROM), floppy disks, compact disc read-only memory (CD-ROM), optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0104] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0105] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0106] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A planning method for flexible interconnection of distribution areas based on self-consistent power distribution units, characterized in that, The method comprises the following steps: acquiring uncontrollable data of a transformer area, calculating uncontrollable net load of the transformer area based on the uncontrollable data of the transformer area, wherein the uncontrollable data comprises uncontrollable distributed power generation of the transformer area and rigid load power of the transformer area; calculating complementary matching degrees of transformer areas in a distribution network based on the uncontrollable net load of the transformer area; selecting self-consistent power distribution units under two transformer areas with the highest complementary matching degrees for planning, constructing an objective function and constraint conditions of the self-consistent power distribution units; solving the objective function and outputting a planning result; solving the objective function and outputting a planning result, specifically comprising: Solving the objective function obtains the rated capacity of the energy storage and controllable distributed power generation in the self-consistent power distribution unit and the benefit after the self-consistent power distribution unit obj ; Set a critical value, if the benefits obj If the value exceeds the set threshold, the complementarity matching degree between any two remaining transformer areas will be recalculated, and the two transformer areas with the highest complementarity matching degree will be replanned. obj If the value is less than the critical value, the planning ends. Based on the original calculation results, the rated capacity of energy storage and controllable distributed generation in the self-consistent distribution unit is planned, and the planning results are output. The self-consistent power distribution units under the two station areas with the highest complementary matching degree are selected for planning, a target function of the self-consistent power distribution unit is constructed, and planning variables of the target function are capacities of controllable distributed power generation and energy storage in the self-consistent power distribution unit i , assuming that the planning capacities of energy storage and controllable distributed power generation in the self-consistent power distribution unit under the station area and are Therefore, the objective function of the planning can be expressed as: In the formula: obj To assess the benefits of installing self-contained power distribution units; and They are respectively t Cost coefficient per unit energy loss in AC and DC systems at all times; for t The unit capacity compensation cost coefficient for flexible loads participating in demand response in a time-consistent distribution unit; and are energy storage and respectively Investment coefficient per unit capacity for controllable distributed generation; , This represents the number of time periods in a day, with a time step of 1 hour. The value is 24; This represents the change in AC network losses. This represents the change in DC network losses. This represents the change in flexible load; The planned energy storage capacity in a self-consistent power distribution unit; This refers to the planned capacity of controllable distributed generation in a self-consistent distribution unit.

2. The method of claim 1, wherein, In the step of acquiring uncontrollable data of a transformer area and calculating uncontrollable net load of the transformer area based on the uncontrollable data of the transformer area, the uncontrollable net load is: In the formula, is the uncontrollable net load of the transformer area i; is t is the rigid load power of the transformer area at the moment; is t is the uncontrollable distributed power generation power of the transformer area at the moment, , is the number of time periods in a day, with a time step of 1 hour, is 24.

3. The method of claim 2, wherein, The step of calculating complementary matching degrees of transformer areas in a distribution network comprises calculating longitudinal complementary matching degrees of the transformer areas and horizontal complementary matching degrees of the transformer areas, and the formulae are as follows: In the formula, is the complementary matching degree of the transformer substation; is the longitudinal complementary matching degree of the transformer substation; is the lateral complementary matching degree of the transformer substation.

4. The method of claim 3, wherein, The longitudinal complementary matching degree of the transformer area is the ratio of the average value and the maximum value of the uncontrollable net load difference of the transformer area i and the transformer area j , which reflects the smoothness of the new load curve after the superposition of the uncontrollable net load curves of the two transformer areas, and is expressed by the following formula: In the formula: is the uncontrollable net load of the transformer area; i is the uncontrollable net load of the transformer area; is the uncontrollable net load of the transformer area; j is the uncontrollable net load of the transformer area.

5. The method of claim 4, wherein, The transverse complementary matching degree of the transformer area is the minimum value and the maximum value ratio of the sum of the uncontrollable net load of the transformer area i and the transformer area j at each moment, which reflects the smoothness of the new load curve after the superposition of the uncontrollable net load curves of the two transformer areas, and is expressed by the formula: In the formula: is the smoothness of the curve as a whole.

6. The method of claim 5, wherein, In the constraint, including: for any area i In terms of the power balance constraints, as follows, In the formula: and respectively t rigid load and flexible load power at the moment, both of which can be obtained by load prediction; and respectively t uncontrollable distributed power generation and controllable distributed power generation at the moment, the former can be predicted by new energy power generation, and the latter belongs to the control variable; is t energy storage and self-consistent distribution unit interaction power at the moment, the energy storage charging is positive, and vice versa; is t self-consistent distribution unit and external interaction power at the moment, the outflow is positive, and vice versa; , is the number of time periods in a day, with 1 hour as the time step, the value is 24.

7. The method of claim 6, wherein, In the constraint conditions, the following constraints need to be met during equipment operation: The method comprises the following steps: ； In the formula, and are the lower limit and rated capacity of the uncontrollable distributed generation output of the substation i respectively; and are the lower limit and rated capacity of the controllable distributed generation output of the substation i respectively; In the formula, is a district i The energy storage rated capacity to be planned in the self-consistent distribution unit.

8. A device for planning flexible interconnection of a distribution area based on a self-consistent distribution unit according to any one of claims 1-7, characterized in that, a data acquisition module, configured to acquire uncontrollable data of a transformer area, calculate uncontrollable net load of the transformer area based on the uncontrollable data of the transformer area, wherein the uncontrollable data comprises uncontrollable distributed power generation of the transformer area and rigid load power of the transformer area; a data matching module, configured to calculate complementary matching degrees of transformer areas in a distribution network based on the uncontrollable net load of the transformer area; a model construction module, configured to select self-consistent power distribution units under two transformer areas with the highest complementary matching degrees for planning, construct an objective function and constraint conditions of the self-consistent power distribution units; a planning output module, configured to solve the objective function and output a planning result. ​

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