Power distribution method, device, equipment, medium and product for flexible interconnection of low-voltage transformer area

Abstract

The invention discloses a power distribution method, device and equipment for flexible interconnection of a low-voltage transformer area, a medium and a product. The method comprises the following steps: acquiring first power parameters corresponding to at least two transformer areas in the low-voltage transformer area flexible interconnection system, a second power parameter of a direct current system and cost parameters required by the at least two transformer areas; based on the first power parameter, the second power parameter and the cost parameter, constructing an optimization objective function of power distribution of each transformer area in the low-voltage transformer area flexible interconnection system; determining the initial optimal power distribution of the power distribution of each transformer area based on the optimization objective function; and according to the initial optimal power distribution and a preset inter-station power balance control strategy, performing target optimal power distribution on each station area. According to the embodiment of the invention, through the technical scheme, interconnection and mutual supply among the transformer areas can be realized, the optimal power is distributed for each transformer area, the utilization rate of the power is improved, and the efficient consumption of the distributed power supply is promoted, so that the economic and safe operation of the system is realized.

Description

Technical Field

[0001] The present invention relates to the field of software development technology, and in particular to a power distribution method, device, equipment, medium and product for flexible interconnection of low-voltage stations. Background Art

[0002] At present, most methods use power electronic devices to replace the interconnecting switches of multi-segment distribution lines to form the form of interconnection of substations. This method increases the investment in electronic power conversion devices and cannot flexibly adjust the power of each substation. At the same time, the existing interconnected distribution network is mainly oriented towards the medium-voltage distribution network level, and rarely addresses the power quality problems such as voltage over-limit and three-phase imbalance caused by photovoltaic grid connection to distribution substations. The AC and DC loads in distribution substations are growing rapidly, and the matching degree of distributed photovoltaics and loads based on substations is complex and changeable. Problems such as distributed photovoltaic reverse transmission, transformer overload and load rate imbalance between substations are also becoming increasingly prominent. How to achieve interconnection and mutual supply between substations and appropriate power distribution between substations is an urgent problem to be solved. Summary of the invention

[0003] In view of this, the present invention provides a power distribution method, device, equipment, medium and product for flexible interconnection of low-voltage substations, which can realize interconnection and mutual supply between substations, allocate optimal power to each substation, improve power utilization, promote efficient consumption of distributed power sources, thereby realizing economical and safe operation of the system.

[0004] According to one aspect of the present invention, an embodiment of the present invention provides a power distribution method for flexible interconnection of low-voltage areas, which is applied to a flexible interconnection system of low-voltage areas, wherein the flexible interconnection system of low-voltage areas comprises: an AC system and a DC system; interconnecting at least two areas included in the AC system through the DC system;

[0005] The method comprises:

[0006] Obtaining first power parameters corresponding to at least two substations in the low-voltage substation flexible interconnection system, a second power parameter of the DC system, and cost parameters required by the at least two substations;

[0007] An optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system is constructed based on the first power parameter, the second power parameter and the cost parameter; wherein the optimization objective function takes the operation cost of the low-voltage substation flexible interconnection system as the minimum, and the constraints of the optimization objective function include: distribution network power constraints and substation voltage constraints;

[0008] Determine the initial optimal power allocation of each of the power distribution areas based on the optimization objective function;

[0009] According to the preset inter-station power balancing control strategy, target optimal power allocation is performed on each of the substations after the initial optimal power allocation; wherein the preset inter-station power balancing control strategy is a power balancing control strategy between two interconnected substations with the same capacity when the capacities of the distribution transformers corresponding to the two interconnected substations are the same.

[0010] According to another aspect of the present invention, an embodiment of the present invention further provides a power distribution device for flexible interconnection of low-voltage areas, the power distribution device for flexible interconnection of low-voltage areas is characterized in that it is applied to a flexible interconnection system of low-voltage areas, the flexible interconnection system of low-voltage areas comprising: an AC system and a DC system; at least two areas included in the AC system are interconnected through the DC system;

[0011] The device comprises:

[0012] A parameter acquisition module, used to acquire a first power parameter injected by the distribution network into the at least two substations within a preset time, a second power parameter injected into the DC system, and a cost parameter required by the at least two substations;

[0013] An optimization function construction module is used to construct an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system based on the first power parameter, the second power parameter and the cost parameter; wherein the optimization objective function takes the operation cost of the low-voltage substation flexible interconnection system as the minimum, and the constraint conditions of the optimization objective function include: distribution network power constraint and substation voltage constraint;

[0014] An initial power allocation module, used to determine the initial optimal power allocation of each of the power distribution areas based on the optimization objective function;

[0015] The target power allocation module is used to perform target optimal power allocation on each of the substations after the initial optimal power allocation according to a preset inter-substation power balance control strategy.

[0016] According to another aspect of the present invention, an embodiment of the present invention further provides an electronic device, the electronic device comprising:

[0017] at least one processor; and

[0018] a memory communicatively connected to the at least one processor; wherein,

[0019] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the power distribution method for flexible interconnection of low-voltage substations described in any embodiment of the present invention.

[0020] According to another aspect of the present invention, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the power distribution method for flexible interconnection of low-voltage substations described in any embodiment of the present invention when executed.

[0021] According to another aspect of the present invention, an embodiment of the present invention further provides a computer program product, characterized in that the computer program product includes a computer program, and when the computer program is executed by a processor, it implements the power distribution method for flexible interconnection of low-voltage substations described in any embodiment of the present invention.

[0022] The technical solution of the embodiment of the present invention is to interconnect and assist substations with complementary operations in an AC / DC flexible manner. By constructing the optimization objective function of the power allocation of each substation in the flexible interconnection system of low-voltage substations and the corresponding constraints, the initial optimal power allocation is made for each substation. On this basis, the target optimal power allocation is made for each substation after the initial optimal power allocation according to the preset power balancing control strategy between substations. This can realize the interconnection and mutual supply between substations, allocate the optimal power to each substation, and enable the system to have more flexible power regulation capabilities, improve power utilization, and promote efficient consumption of distributed power sources, thereby realizing economical and safe operation of the system.

[0023] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A flow chart of a power distribution method for flexible interconnection of low-voltage stations provided in one embodiment of the present invention;

[0026] Figure 2 A flow chart of a power distribution method for flexible interconnection of low-voltage stations provided in one embodiment of the present invention;

[0027] Figure 3 A schematic diagram of the structure of a low-voltage area flexible interconnection system provided by one embodiment of the present invention;

[0028] Figure 4A structural block diagram of a power distribution device for flexible interconnection of low-voltage stations provided in one embodiment of the present invention

[0029] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] In one embodiment, Figure 1 A flow chart of a power distribution method for flexible interconnection of low-voltage substations provided in one embodiment of the present invention. This embodiment can be applied to the situation where optimal power distribution is performed between various substations in a low-voltage substation flexible interconnection system. The method can be executed by a power distribution device for flexible interconnection of low-voltage substations. The power distribution device for flexible interconnection of low-voltage substations can be implemented in the form of hardware and / or software. The power distribution device for flexible interconnection of low-voltage substations can be configured in an electronic device.

[0033] like Figure 1 As shown, the power distribution method for low-voltage flexible interconnection in this embodiment is applied to a low-voltage flexible interconnection system. The specific steps of the power distribution method for low-voltage flexible interconnection include:

[0034] S110, obtaining first power parameters corresponding to at least two substations in the low-voltage substation flexible interconnection system, second power parameters of the DC system, and cost parameters required by at least two substations.

[0035] Among them, the first power parameter refers to the power parameter corresponding to each substation in the AC system; the second power parameter refers to the power parameter corresponding to the DC system; in one embodiment, the first power parameter includes: the power injected by the distribution network into at least two substations and the output power of each substation to the DC system; the second power parameter includes: the power injected by the distribution network into the DC system and the power injected by the DC system into at least two substations; the cost parameters include: the power purchase cost from the upper-level power grid, the cost of distributed photovoltaics included in at least two substations, and the charging and discharging operation and maintenance cost of the energy storage device included in at least two substations.

[0036] In this embodiment, the low-voltage area flexible interconnection system includes: an AC system and a DC system; at least two areas included in the AC system are interconnected through the DC system, and the AC system includes multiple areas, each of which includes distributed photovoltaics, energy storage devices and charging piles; the DC system is also equipped with distributed photovoltaics, charging piles and energy storage devices, and the various areas included in the AC system can be interconnected through the DC system. For example, the power distribution can be performed by connecting to the 750V DC bus through a cable, and the change of the 750V DC bus voltage can reflect the power flow and real-time energy balance of the system. In this embodiment, the area in the flexible interconnection state integrates the characteristics of the AC system and the DC system, and has a more powerful power regulation capability and large-scale distributed power grid adaptability. In the form of AC / DC hybrid areas, the investment in power electronic conversion devices can be greatly reduced, the economy of the distribution network is improved, the harmonic content is reduced, and the power quality is improved.

[0037] In this embodiment, sensors and other collection equipment can be used to collect relevant parameter information corresponding to at least two substations, and read in the power of the distribution networks corresponding to at least two substations in the low-voltage substation flexible interconnection system injected into the at least two substations and the output power of each substation to the DC system, as well as the power of the distribution network of the DC system injected into the DC system and the power of the DC system injected into at least two substations, as well as the power purchase cost from the upper-level power grid required for at least two substations, the cost of distributed photovoltaics included in at least two substations, and the charging, discharging, operation and maintenance cost of the energy storage devices included in at least two substations.

[0038] S120, constructing an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system based on the first power parameter, the second power parameter and the cost parameter.

[0039] Among them, the optimization objective function aims to minimize the operating cost of the low-voltage substation flexible interconnection system, and the constraints of the optimization objective function include: distribution network power constraints and substation voltage constraints.

[0040] In this embodiment, since it is necessary to optimize the power allocation for each substation, on the basis of obtaining the first power parameters corresponding to at least two substations, the second power parameters of the DC system and the cost parameters required by at least two substations, the first power parameters corresponding to at least two substations, the second power parameters of the DC system and the cost parameters required by at least two substations can be used to construct the optimization objective function of the power allocation of each substation in the low-voltage substation flexible interconnection system; in one embodiment, the power flow of the low-voltage substation flexible interconnection system interconnected by multiple substations can be modeled, and the power of the DC system can be modeled to obtain the power model of the multi-substation interconnection model. On this basis, the effect of the flexible interconnection of the substations in improving the photovoltaic absorption rate and realizing the economic and safe operation of the system is focused on, and the seasonal fluctuation factors of the first distributed photovoltaic and the load of each substation are considered to construct the optimization objective function. In other embodiments, the optimization model can also be established through the comprehensive economic indicators, power generation cost coefficients, environmental pollution indicators and primary energy waste indicators of each energy storage unit in each substation. The optimization model may include establishing a comprehensive economic indicator model, an objective function model, a power balance constraint model and a power limit constraint model.

[0041] S130: Determine the initial optimal power allocation for each substation based on the optimization objective function.

[0042] Among them, the initial optimal power allocation refers to the initial optimal power allocated to each substation. If the initial optimal power meets the substation load of the interconnected substation, the initial optimal power can be directly allocated to each substation as the target optimal power. Of course, if the initial optimal power does not meet the substation load of the interconnected substation, power can be allocated to each substation based on the power balancing control strategy between two adjacent interconnected substations to obtain the optimal power corresponding to the substation.

[0043] In this embodiment, the optimal solution of the optimization objective function is solved, and the optimal solution is used as the initial optimal power allocation of each substation. Since the optimization objective function is nonlinear or non-convex, in some embodiments, the nonlinear constraint or non-convex optimization problem of the optimization objective function can be converted into a linear constraint or a convex optimization problem by using a preset second-order cone programming method. On this basis, the linear constraint problem or convex optimization problem of the optimization objective function is solved according to the optimization solving tool in the preset programming language to obtain the optimal solution, and the optimal solution is used as the initial optimal power allocation of each substation. It can be understood that since the optimization objective function is a nonlinear problem or a convex optimization problem, the traditional intelligent algorithm has a slow solution speed and is easy to fall into the local optimal situation. For this reason, the nonlinear problem of the optimization objective function can be converted into a linear problem by using a second-order cone programming method to facilitate the solution of the optimization objective function, which has advantages in both solution speed and solution results. Of course, in this embodiment, in addition to using the second-order cone programming method to solve the optimal solution of the optimization objective function, a method can also be used to solve the optimal solution, such as: exhaustive method, heuristic search method and quadratic programming optimization method, which is not limited in this embodiment.

[0044] S140: Perform target optimal power allocation on each substation after initial optimal power allocation according to a preset inter-substation power balance control strategy.

[0045] Among them, the preset inter-station power balancing control strategy is a power balancing control strategy between two interconnected substations with the same capacity when the capacities of the distribution transformers corresponding to the two interconnected substations are the same.

[0046] In this embodiment, the preset inter-station power balancing control strategy can be understood as a pre-configured inter-station power balancing control strategy based on the load imbalance problem between the two interconnected substations when the capacities of the distribution transformers corresponding to the two interconnected substations are the same, so as to perform power flow regulation and achieve consistent load rates of the low-voltage distribution substations at both ends of the flexible interconnected system.

[0047] In some embodiments, the preset inter-station power balancing control strategy is expressed as: Where ΔP DC =P pv +P bat , P bat is the charging and discharging power of the second energy storage device; P pv is the power generation of the second distributed photovoltaic; The power consumed by the load in the first section, is the power consumed by the load in the second section, ΔP DC is the power absorbed or emitted by the DC system to each substation in the AC system;DC >0, it means the DC system sends power to each substation in the AC system. DC When <0, it indicates the power absorbed by the DC system from each substation in the AC system.

[0048] In this embodiment, since the initial optimal power may or may not satisfy the power balance between the two interconnected substations, in order to ensure that there is no load imbalance between the two interconnected substations, a preset inter-substation power balance control strategy can be used to allocate the target optimal power to each substation. Specifically, it is determined whether there is load imbalance between the two interconnected substations after power allocation; if there is load imbalance, the target optimal power is allocated to each substation according to the preset inter-substation power balance control strategy; if there is no load imbalance, the initial optimal power allocation is used as the target optimal power allocation.

[0049] The technical solution of the embodiment of the present invention is to interconnect and assist substations with complementary operations in an AC / DC flexible manner. By constructing the optimization objective function of the power allocation of each substation in the flexible interconnection system of low-voltage substations and the corresponding constraints, the initial optimal power allocation is made for each substation. On this basis, the target optimal power allocation is made for each substation after the initial optimal power allocation according to the preset power balancing control strategy between substations. This can realize the interconnection and mutual supply between substations, allocate the optimal power to each substation, and enable the system to have more flexible power regulation capabilities, improve power utilization, and promote efficient consumption of distributed power sources, thereby realizing economical and safe operation of the system.

[0050] In one embodiment, Figure 2 A flow chart of another power allocation method for flexible interconnection of low-voltage substations provided for one embodiment of the present invention. Based on the above embodiments, this embodiment constructs an optimization objective function for the power allocation of each substation in the low-voltage substation flexible interconnection system based on the first power parameter, the second power parameter and the cost parameter, determines the initial optimal power allocation of the power allocation of each substation based on the optimization objective function; and further refines the target optimal power allocation for each substation according to the initial optimal power allocation and the preset inter-substation power balancing control strategy.

[0051] like Figure 2 As shown, the power distribution method for flexible interconnection of low-voltage stations in this embodiment may specifically include the following steps:

[0052] S210, obtaining first power parameters corresponding to at least two substations in the low-voltage substation flexible interconnection system, a second power parameter of the DC system, and cost parameters required by at least two substations.

[0053] S220: For each substation included in the AC system, respectively obtain the power generated by the first distributed photovoltaic power generation system in each substation, and the charging power or discharging power of each first energy storage device.

[0054] In this embodiment, the AC system includes multiple substations, each of which includes a first distributed photovoltaic, a first energy storage device and a first load. For each substation included in the AC system, the power emitted by the first distributed photovoltaic in each substation and the charging power or discharging power of each first energy storage device are obtained respectively.

[0055] S230, constructing an objective function for power allocation in each substation based on the power generated by each first distributed photovoltaic, the power injected into at least two substations by the distribution network, the charging power or discharging power of each first energy storage device, the cost of purchasing electricity from the upper-level power grid, the cost of the first distributed photovoltaic included in at least two substations, and the charging and discharging operation and maintenance cost of the first energy storage device included in at least two substations.

[0056] In this embodiment, an objective function for power allocation in each substation is constructed. The objective function can be constructed by the power generated by each first distributed photovoltaic, the power injected into at least two substations by the distribution network, the charging power or discharging power of each first energy storage device, the cost of purchasing electricity from the upper-level power grid, the cost of the first distributed photovoltaic included in at least two substations, and the charging and discharging operation and maintenance cost of the first energy storage device included in at least two substations.

[0057] Specifically, for each substation included in the AC system, the power generated by the first distributed photovoltaic system and the power consumed by the first load are obtained respectively, and a first power model corresponding to each substation is constructed based on the power injected by the distribution network into at least two substations, the output power of each substation to the DC system, the power generated by the first distributed photovoltaic system and the power consumed by the first load; for the DC system, the power generated by the second energy storage device, the power generated by the second distributed photovoltaic system and the power consumed by the second load are obtained, and a second power model corresponding to the DC system is constructed based on the power injected by the distribution network into the DC system, the power generated by the second energy storage device, the power generated by the second distributed photovoltaic system and the power consumed by the second load; a power interconnection model of the low-voltage substation flexible interconnection system is determined based on the first power model and the second power model; and the power interconnection model is converted into an objective function for power allocation of each substation in the low-voltage substation flexible interconnection system based on preset assumptions. It should be noted that the preset assumptions include: the first assumption and the second assumption. The first assumption is: the AC source, DC source, and load are accessed in different areas, there is no difference in the optical resources of each area, and the distributed photovoltaic power generation in each area is equivalent to one unit connected to the DC area of ​​the area; the second assumption is: the status information of each area is collected and summarized by the preset coordination controller.

[0058] More specifically, the first power model can be expressed as: Where: It represents the power injected into the distribution network 10kV AC bus into the substation i (i∈N), Indicates the power generated by distributed photovoltaics, Indicates the load power consumption, It indicates the output power of the station area i to the 750V DC bus. The second power model can be expressed by the formula: P DC +P pvDC +P DCbat =P DCload , where: P DC It represents the power injected into the DC system by the 750V DC bus, P pvDC P represents the power generated by distributed photovoltaic power in the DC system. DCbat Indicates the power output of the first energy storage device in the DC system, P DCload Indicates the power consumed by the first DC load in the DC system. The power interconnection model can be expressed as: Since the power interconnection model focuses on studying the effects of flexible interconnection of substations in improving the photovoltaic absorption rate and achieving economic and safe operation of the system, the following assumptions are made for the interconnection system model: 1) The AC and DC sources and loads in each substation are accessed in different areas, and there is no difference in the light resources of each substation in the interconnection system. The distributed photovoltaics in each substation are equivalent to a unit connected to the DC area of ​​the substation; 2) The state information of the source and load equipment in the interconnection system is collected and summarized by the coordination controller, and the master station is monitored locally to participate in the day-ahead economic dispatch of the interconnection system, which is the objective function. Specifically, the objective function can be expressed as: In the formula, T is the dispatch period, N is the number of interconnected substations in the interconnected system, C1(t) is the cost of purchasing electricity from the upper power grid at time t, and C2(t) is the cost of distributed photovoltaic at time t. The operation and maintenance costs of energy storage charging and discharging, and is the charging and discharging power of the energy storage in area i at time t; It is the power injected into the distribution network 10kV AC bus into the i-th substation (i∈N) at the t-th moment, and the distributed photovoltaic power output of the i-th substation at the t-th moment.

[0059] S240, constructing an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system; wherein the optimization objective function is constructed by taking into account the seasonal fluctuation factors of each first distributed photovoltaic and each substation load.

[0060] In this embodiment, the purpose of model optimization is to improve the absorption rate of distributed photovoltaics through flexible interconnection, and at the same time realize the optimal power distribution between interconnected stations. Economically speaking, it can be expressed as the minimum cost of the entire distribution network to purchase electricity from the upper main grid. To this end, on the basis of the objective function, the optimization objective function of power distribution of each area in the low-voltage area flexible interconnection system is constructed by considering the seasonal fluctuations of distributed photovoltaics and loads.

[0061] In one embodiment, the optimization objective function of power allocation of each area in the low-voltage area flexible interconnection system is expressed as follows:

[0062] In the formula, T is the dispatching period, N is the number of interconnected areas in the low-voltage area flexible interconnection system, C1(t) is the cost of purchasing electricity from the upper-level power grid at time t, C2(t) is the cost of each first distributed photovoltaic at time t, s is the number of seasons, and D s is the number of days in season s in a year, N buy is the total number of 10kV nodes included in the distribution network, and each node corresponds to a substation; is the power injected into the 10 kV AC bus of the distribution network into the i-th substation (i∈N) in season s, is the power generated by the first distributed photovoltaic power station in the ith area at the tth time in season s, The power injected into the ith station of the DC system in season s.

[0063] In one embodiment, the stability and safety of AC substation operation must meet the power balance of each substation under each bus. To ensure the safe operation of the substation, the substation voltage should meet the node voltage constraint. Considering seasonal conditions, the distribution network power constraint in the constraint condition of the optimization objective function is expressed by the formula:

[0064] In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase difference between node i at time t in season s and node j at time t in season s, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station, B ii is the self-susceptance of the ith substation;

[0065] The station area voltage constraint in the constraint condition of the optimization objective function is expressed as follows:

[0066] In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase angle difference between node i at time t in season s and node j at time t in season s, is the reactive power injected into the ith transformer substation by the DC system at time t in season s, δ(i) represents the set of transformer substations connected to the ith transformer substation, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

[0067] S250, solving the optimal solution of the optimization objective function according to a preset second-order cone programming method, and using the optimal solution as the initial optimal power allocation for power allocation of each substation.

[0068] Among them, the preset second-order cone programming method is a method for solving a class of convex optimization problems, in which both the objective function and the constraints contain second-order cone constraints. Second-order cone programming is a mathematical programming on a convex cone in a linear space, which can transform non-convex problems and has more advantages in terms of solution speed and required results.

[0069] In this embodiment, the optimal solution of the optimization objective function is solved according to the preset second-order cone programming method, and the optimal solution is used as the initial optimal power allocation for the power allocation of each substation. Specifically, the optimization objective function is transformed into a linear problem according to the preset second-order cone programming method, and then the optimal solution of the transformed optimization objective function is solved.

[0070] In some embodiments, the optimal solution of the optimization objective function is solved according to a preset second-order cone programming method, and the optimal solution is used as the initial optimal power allocation for each substation, including: using a preset second-order cone programming method to convert the nonlinear constraint problem of the optimization objective function into a linear constraint problem; solving the linear constraint problem of the optimization objective function according to the optimization solving tool in the preset programming language to obtain the optimal solution, and using the optimal solution as the initial optimal power allocation for each substation; wherein the optimization solving tool at least includes: yalmip solving tool. In this embodiment, the yalmip solving tool is an optimization solving tool, which is a MATLAB toolkit that can integrate the optimization solver cplex. After setting the optimal objective function and the corresponding constraints, the yalmip solving tool will automatically select a suitable solver to solve the problem and obtain a global optimal solution.

[0071] Specifically, the preset second-order cone programming method is used to convert the nonlinear constraint problem of the optimization objective function into a linear constraint problem, including: introducing the first variable Second variable and the third variable Z ij,s (t), and use the first variable Second variable and the third variable Z ij,s (t) Replace the optimization objective function constraints and θ ij,s (t) to transform the nonlinear constraint problem into a linear constraint problem;

[0072] Among them, the first variable is used Second variable and the third variable Z ij,s (t) Replace the optimization objective function constraints and θ ij,s (t), expressed as: The distribution network power constraint can be converted into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station; the voltage constraint condition of the station can be transformed into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

[0073] More specifically, solving the linear constraint problem of the optimization objective function according to the optimization solving tool in the preset programming language includes: determining the defined parameter matrix; wherein the parameter matrix may include the power injected into the ith substation by the 10 kV AC busbar of the distribution network in the season s in the optimization objective function. The power generated by the first distributed photovoltaic power station in the i-th area at the t-th time in season s The power injected into the ith station by the DC system in season s Determine the optimization objective function and the linear constraint problem corresponding to the optimization objective function; call the CPLEX solver through the yalmip solving tool to solve the global optimal solution of the optimization objective function under the linear constraint problem.

[0074] S260, determine whether load balancing is achieved between two interconnected substations after power is allocated to each substation according to the initial optimal power allocation; if so, execute S270; if not, execute S280.

[0075] In this embodiment, power is allocated to each substation according to the initial optimal power allocation, and it is determined whether load imbalance occurs between two interconnected substations after the power allocation.

[0076] S270: Use the initial optimal power allocation as the target optimal power allocation.

[0077] In this embodiment, when there is no load imbalance, the initial optimal power allocation is used as the target optimal power allocation.

[0078] S280: Allocate target optimal power to each substation according to the preset inter-substation power balancing control strategy.

[0079] In this embodiment, in the case of load imbalance, the target optimal power allocation is performed for each substation according to the preset inter-substation power balance control strategy. Unbalanced load rates between substations will result in low economic operation of light-loaded lines and low voltage limit violations caused by heavy-loaded lines, which will affect the economy and reliability of the system. Therefore, it is necessary to adopt certain power balance control strategies for power flow regulation to achieve consistent load rates of low-voltage distribution substations at both ends of the flexible interconnection system. Assuming that the capacity of the distribution transformers at both ends is equal, the power allocation principles are as follows: Where ΔP DC =P pv +P bat , P bat is the charging and discharging power of the second energy storage device; P pv is the power generation power of the second distributed photovoltaic system; The power consumed by the load in the first section, is the power consumed by the load in the second section, ΔP DC is the power absorbed or emitted by the DC system to each substation in the AC system; DC >0, it means the DC system sends power to each substation in the AC system. DC When <0, it indicates the power absorbed by the DC system from each substation in the AC system.

[0080] Exemplary, take 5 substations as an example to illustrate. After power is allocated to the 5 substations according to the initial optimal power allocation, there is a situation where the load balance is not satisfied between the first substation and the second substation among the 5 substations. For example, the optimal power allocation has been performed for the 5 substations. For the two interconnected substations, if the output capacity of the two transformers is the same, assuming that the optimal solution that may be obtained according to the objective function is that the first substation needs 50w and the second substation needs 90w, then this much power is directly allocated. Power can be provided from photovoltaics. If the load rate of the first substation is 20% and the load rate of the second substation is 90%, one substation will be lightly loaded and the other will be heavily loaded. At this time, the target optimal power allocation can be performed for each substation according to the preset power balancing control strategy between substations.

[0081] The above technical scheme in this embodiment uses mathematical modeling of the low-voltage substation flexible interconnection system to establish a power mathematical model and constraint conditions of the flexible interconnected substation, and optimizes the model. The second-order cone programming is introduced to solve the optimal solution of the optimization objective function, and the optimal solution is used as the initial optimal power allocation for the power allocation of each substation. The power allocation of the substation is completed under the condition of load balancing of the substation, and the interconnection and mutual supply between substations are realized. The flexible interconnection of substations enables the system to have more flexible power regulation capabilities. While ensuring the safety of system power supply, it will also improve power utilization and promote efficient consumption of distributed power sources.

[0082] In one embodiment, to facilitate understanding of the low voltage area flexible interconnection system structure, Figure 3 A schematic diagram of the structure of a low-voltage distribution area flexible interconnection system provided for one embodiment of the present invention. N (N = 1, 2, 3, ...) low-voltage distribution areas are all connected with distributed photovoltaic, charging piles and energy storage devices, and are interconnected through a 750V DC bus. The DC system is also equipped with distributed photovoltaic, charging piles and energy storage devices, which are connected to the 750V DC bus through cables for power distribution. Changes in the 750V DC bus voltage can reflect the power flow and real-time energy balance of the system.

[0083] In one embodiment, Figure 4 This is a structural block diagram of a power distribution device for low-voltage flexible interconnection provided by an embodiment of the present invention. The device is suitable for optimal power distribution between various areas in a low-voltage flexible interconnection system. The device can be implemented by hardware / software. It can be configured in an electronic device to implement a power distribution method for low-voltage flexible interconnection in an embodiment of the present invention.

[0084] like Figure 4As shown, the device includes: a low-voltage area flexible interconnection system, the low-voltage area flexible interconnection system includes: an AC system and a DC system; at least two areas included in the AC system are interconnected through the DC system;

[0085] The device comprises:

[0086] The parameter acquisition module 410 is used to acquire a first power parameter injected by the distribution network into the at least two substations within a preset time, a second power parameter injected into the DC system, and a cost parameter required by the at least two substations;

[0087] The optimization function construction module 420 is used to construct an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system based on the first power parameter, the second power parameter and the cost parameter; wherein the optimization objective function takes the operation cost of the low-voltage substation flexible interconnection system as the minimum, and the constraint conditions of the optimization objective function include: distribution network power constraint and substation voltage constraint;

[0088] An initial power allocation module 430, configured to determine the initial optimal power allocation for each of the substation power allocations based on the optimization objective function;

[0089] The target power allocation module 440 is used to perform target optimal power allocation to each of the substations after the initial optimal power allocation according to a preset inter-substation power balance control strategy.

[0090] In the embodiment of the present invention, the optimization function construction module and the initial power allocation module construct the optimization objective function of the power allocation of each substation in the low-voltage substation flexible interconnection system and the corresponding constraints, and perform the initial optimal power allocation for the power allocation of each substation. The target power allocation module performs the target optimal power allocation for each substation based on the initial optimal power allocation and the preset power balance control strategy between substations, realizes the interconnection and mutual supply between substations, allocates the optimal power to each substation, improves the power utilization rate, promotes the efficient consumption of distributed power sources, and thus realizes the economical and safe operation of the system.

[0091] In one embodiment, the first power parameter includes: the power injected by the distribution network into the at least two substations and the output power of each of the substations to the DC system; the second power parameter includes: the power injected by the distribution network into the DC system and the power injected by the DC system into the at least two substations;

[0092] The cost parameters include: the cost of purchasing electricity from the upper-level power grid, the cost of distributed photovoltaics included in the at least two substations, and the charging, discharging, operation and maintenance costs of the energy storage devices included in the at least two substations.

[0093] In one embodiment, the at least two areas respectively include a first energy storage device, a first distributed photovoltaic device and a first load;

[0094] Accordingly, the optimization function building module 420 includes:

[0095] An acquisition unit, for acquiring, for each substation included in the AC system, respectively the power generated by the first distributed photovoltaic power generation system in each substation, and the charging power or discharging power of each first energy storage device;

[0096] An objective function construction unit, configured to construct an objective function for power allocation of each area based on the power generated by each of the first distributed photovoltaics, the power injected by the distribution network into the at least two areas, the charging power or discharging power of each of the first energy storage devices, the cost of purchasing electricity from the upper-level power grid, the cost of the first distributed photovoltaics included in the at least two areas, and the charging and discharging operation and maintenance cost of the first energy storage devices included in the at least two areas;

[0097] An optimization objective function construction unit is used to construct an optimization objective function for power distribution of each substation in the low-voltage substation flexible interconnection system based on the objective function; wherein the optimization objective function is constructed by taking into account the seasonal fluctuation factors of each first distributed photovoltaic and each substation load.

[0098] In one embodiment, the optimization objective function of power allocation of each area in the low-voltage area flexible interconnection system is expressed as follows:

[0099] Where T is the dispatching period, N is the number of interconnected areas in the low-voltage area flexible interconnection system, C1(t) is the cost of purchasing electricity from the upper-level power grid at time t, C2(t) is the cost of each of the first distributed photovoltaics at time t, s is the number of seasons, and D s is the number of days in season s in a year, N buy is the total number of 10kV nodes included in the distribution network, each node corresponds to a substation; is the power injected into the 10 kV AC bus of the distribution network into the i-th substation (i∈N) in season s, is the power generated by the first distributed photovoltaic power station in the ith area at the tth time in season s, The power injected into the ith station of the DC system in season s.

[0100] In one embodiment, the power distribution network constraint in the constraint condition of the optimization objective function is expressed as follows:

[0101] In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase difference between node i at time t in season s and node j at time t in season s, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station, B ii is the self-susceptance of the ith substation;

[0102] The station area voltage constraint condition in the constraint condition of the optimization objective function is expressed as follows:

[0103] In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase angle difference between node i at time t in season s and node j at time t in season s, is the reactive power injected into the ith transformer substation by the DC system at time t in season s, δ(i) represents the set of transformer substations connected to the ith transformer substation, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

[0104] In one embodiment, the initial power allocation module 430 includes:

[0105] The solving unit is used to solve the optimal solution of the optimization objective function according to a preset second-order cone programming method, and use the optimal solution as the initial optimal power allocation for the power allocation of each substation.

[0106] In one embodiment, the solving unit includes:

[0107] A problem conversion subunit, used for converting the nonlinear constraint problem of the optimization objective function into a linear constraint problem by using a preset second-order cone programming method;

[0108] A solving subunit, used for solving the linear constraint problem of the optimization objective function according to an optimization solving tool in a preset programming language to obtain an optimal solution, and using the optimal solution as the initial optimal power allocation of each substation;

[0109] Wherein, the optimization solution tool at least includes: yalmip solution tool.

[0110] In one embodiment, the problem conversion subunit is specifically used for:

[0111] Introducing the first variable Second variable and the third variable Z ij,s (t), and using the first variable The second variable and the third variable Z ij,s (t) replace the optimization objective function constraint condition and θ ij,s (t) to transform the nonlinear constraint problem into a linear constraint problem;

[0112] Among them, using the first variable The second variable and the third variable Z ij,s (t) replace the optimization objective function constraint condition and θ ij,s (t), expressed as: The distribution network power constraint can be converted into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station area; the station area voltage constraint condition can be converted into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

[0113] In one embodiment, the target power allocation module 440 includes:

[0114] A judging unit, used for judging whether load balancing is satisfied between two interconnected stations after power is allocated to each station area according to the initial optimal power allocation;

[0115] A first allocation unit, configured to use the initial optimal power allocation as the target optimal power allocation if load balancing is satisfied;

[0116] The second allocation unit is used to allocate target optimal power to each substation according to the preset inter-substation power balance control strategy if load balancing is not satisfied.

[0117] In one embodiment, the DC system includes a second energy storage device, a second distributed photovoltaic device, and a second load;

[0118] Correspondingly, the preset inter-station power balancing control strategy is expressed by the formula: Where ΔP DC =P pv +P bat , P bat is the charging and discharging power of the second energy storage device; P pv is the power generation power of the second distributed photovoltaic system; The power consumed by the load in the first section, is the power consumed by the load in the second section, ΔP DC is the power absorbed or emitted by the DC system to each substation in the AC system; DC >0, it means the DC system sends power to each substation in the AC system. DC When <0, it indicates the power absorbed by the DC system from each substation in the AC system.

[0119] The power distribution device for flexible interconnection of low-voltage areas provided in the embodiment of the present invention can execute the power distribution method for flexible interconnection of low-voltage areas provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0120] In one embodiment, Figure 5 A schematic diagram of the structure of an electronic device provided for an embodiment of the present invention. The electronic device 10 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0121] like Figure 5As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0122] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0123] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 11 executes the various methods and processes described above, such as a power distribution method for flexible interconnection of low-voltage stations.

[0124] In some embodiments, the power distribution method of the low-voltage flexible interconnection of the platform can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the power distribution method of the low-voltage flexible interconnection of the platform described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the power distribution method of the low-voltage flexible interconnection of the platform by any other suitable means (for example, by means of firmware).

[0125] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0126] The computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable low-voltage area flexible interconnected power distribution device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0127] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0128] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0129] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0130] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0131] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0132] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power distribution method for flexible interconnection of low-voltage stations, characterized in that: Applicable to a low-voltage area flexible interconnection system, the low-voltage area flexible interconnection system comprising: an AC system and a DC system; at least two areas included in the AC system are interconnected through the DC system; The method comprises: Obtaining first power parameters corresponding to at least two substations in the low-voltage substation flexible interconnection system, a second power parameter of the DC system, and cost parameters required by the at least two substations; An optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system is constructed based on the first power parameter, the second power parameter and the cost parameter; wherein the optimization objective function takes the operation cost of the low-voltage substation flexible interconnection system as the minimum, and the constraints of the optimization objective function include: distribution network power constraints and substation voltage constraints; Determine the initial optimal power allocation of each of the power distribution areas based on the optimization objective function; According to a preset inter-station power balancing control strategy, target optimal power allocation is performed on each of the stations after the initial optimal power allocation.

2. The method according to claim 1, characterized in that The first power parameter includes: the power injected by the distribution network into the at least two substations and the output power of each of the substations to the DC system; the second power parameter includes: the power injected by the distribution network into the DC system and the power injected by the DC system into the at least two substations; The cost parameters include: the cost of purchasing electricity from the upper-level power grid, the cost of distributed photovoltaics included in the at least two substations, and the charging, discharging, operation and maintenance costs of the energy storage devices included in the at least two substations.

3. The method according to claim 2, characterized in that The at least two areas respectively include a first energy storage device, a first distributed photovoltaic and a first load; Accordingly, the optimization objective function of power allocation of each area in the low-voltage area flexible interconnection system is constructed based on the first power parameter, the second power parameter and the cost parameter, including: For each substation included in the AC system, respectively obtain the power generated by the first distributed photovoltaic power generation system in each substation, and the charging power or discharging power of each first energy storage device; Constructing an objective function for power allocation of each area based on the power generated by each of the first distributed photovoltaics, the power injected by the distribution network into the at least two areas, the charging power or discharging power of each of the first energy storage devices, the cost of purchasing electricity from the upper-level power grid, the cost of the first distributed photovoltaics included in the at least two areas, and the charging and discharging operation and maintenance cost of the first energy storage devices included in the at least two areas; Construct an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system; wherein the optimization objective function is constructed by taking into account the seasonal fluctuation factors of each of the first distributed photovoltaics and each of the substation loads.

4. The method according to claim 3, characterized in that The optimization objective function of the power distribution of each area in the low-voltage area flexible interconnection system is expressed as follows: is the dispatching period, N is the number of interconnected areas in the low-voltage area flexible interconnection system, C1(t) is the cost of purchasing electricity from the upper-level power grid at time t, C2(t) is the cost of each of the first distributed photovoltaics at time t, s is the number of seasons, and D s is the number of days in season s in a year, N buy is the total number of 10kV nodes included in the distribution network, each node corresponds to a substation; is the power injected into the 10 kV AC bus of the distribution network into the i-th substation (i∈N) in season s, is the power generated by the first distributed photovoltaic power station in the ith area at the tth time in season s, The power injected into the ith station of the DC system in season s.

5. The method according to claim 4, characterized in that The power distribution network constraint in the constraint condition of the optimization objective function is expressed as follows: In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase difference between node i at time t in season s and node j at time t in season s, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station, B ii is the self-susceptance of the ith substation; The station area voltage constraint condition in the constraint condition of the optimization objective function is expressed as follows: In the formula, is the voltage amplitude of node i at time t in season s, is the voltage amplitude of node j at time t in season s, θ ij,s (t) is the phase angle difference between node i at time t in season s and node j at time t in season s, is the reactive power injected into the ith transformer substation by the DC system at time t in season s, δ(i) represents the set of transformer substations connected to the ith transformer substation, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

6. The method according to claim 1, characterized in that The determining of the initial optimal power allocation of each of the power distribution areas based on the optimization objective function includes: The optimal solution of the optimization objective function is solved according to a preset second-order cone programming method, and the optimal solution is used as the initial optimal power allocation for the power allocation of each station area.

7. The method according to claim 6, characterized in that The step of solving the optimal solution of the optimization objective function according to a preset second-order cone programming method and using the optimal solution as the initial optimal power allocation for power allocation of each station area includes: Using a preset second-order cone programming method to convert the nonlinear constraint problem of the optimization objective function into a linear constraint problem; Solving the linear constraint problem of the optimization objective function according to the optimization solving tool in the preset programming language to obtain the optimal solution, and using the optimal solution as the initial optimal power allocation of each substation; Wherein, the optimization solution tool at least includes: yalmip solution tool.

8. The method according to claim 5, characterized in that The preset second-order cone programming method is used to transform the nonlinear constraint problem of the optimization objective function into a linear constraint problem, including: Introducing the first variable Second variable and the third variable Z ij,s (t), and using the first variable The second variable and the third variable Z ij,s (t) replace the optimization objective function constraint condition and θ ij,s (t) to transform the nonlinear constraint problem into a linear constraint problem; Among them, using the first variable The second variable and the third variable Z ij,s (t) replace the optimization objective function constraint condition and θ ij,s (t), expressed as: The distribution network power constraint can be converted into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, G ii is the self-conductance of the ith station area; the station area voltage constraint condition can be converted into: In the formula, δ(i) represents the set of stations connected to the ith station, G ij is the mutual conductance between the ith and jth stations, B ij is the mutual admittance between the ith and jth substations, B ii is the self-susceptance of the ith substation.

9. The method according to claim 1, characterized in that: The preset inter-station power balancing control strategy is a power balancing control strategy between two interconnected stations with the same capacity when the capacities of the distribution transformers corresponding to the two interconnected stations are the same.

10. The method according to claim 9, characterized in that Performing target optimal power allocation to each of the substations after the initial optimal power allocation according to a preset inter-substation power balancing control strategy includes: Determine whether load balancing is achieved between two interconnected stations after power is allocated to each station area according to the initial optimal power allocation; If load balancing is satisfied, the initial optimal power allocation is used as the target optimal power allocation; If the load balance is not satisfied, the target optimal power is allocated to each substation according to the preset inter-substation power balance control strategy.

11. The method according to claim 9, characterized in that The DC system includes a second energy storage device, a second distributed photovoltaic device and a second load; Correspondingly, the preset power balance control strategy between stations is expressed by the formula: Among them, ΔP DC =P pv +P bat , P bat is the charging and discharging power of the second energy storage device; P pv is the power generation power of the second distributed photovoltaic system; is the power consumed by the load in the first section, is the power consumed by the load in the second area, the first area and the second area are two interconnected areas with the same capacity; ΔP DC is the power absorbed or emitted by the DC system to each substation in the AC system; DC >0, it means the DC system sends power to each substation in the AC system. DC When <0, it indicates the power absorbed by the DC system from each substation in the AC system.

12. A power distribution device for flexible interconnection of low-voltage areas, characterized in that: Applicable to a low-voltage area flexible interconnection system, the low-voltage area flexible interconnection system comprising: an AC system and a DC system; at least two areas included in the AC system are interconnected through the DC system; The device comprises: A parameter acquisition module, used to acquire a first power parameter injected by the distribution network into the at least two substations within a preset time, a second power parameter injected into the DC system, and a cost parameter required by the at least two substations; An optimization function construction module is used to construct an optimization objective function for power allocation of each substation in the low-voltage substation flexible interconnection system based on the first power parameter, the second power parameter and the cost parameter; wherein the optimization objective function takes the operation cost of the low-voltage substation flexible interconnection system as the minimum, and the constraint conditions of the optimization objective function include: distribution network power constraint and substation voltage constraint; An initial power allocation module, used to determine the initial optimal power allocation of each of the power distribution areas based on the optimization objective function; The target power allocation module is used to perform target optimal power allocation on each of the substations after the initial optimal power allocation according to a preset inter-substation power balance control strategy.

13. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the power distribution method for flexible interconnection of low-voltage substations according to any one of claims 1-11.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the power distribution method for flexible interconnection of low-voltage substations according to any one of claims 1 to 11 when executed.

15. A computer program product, characterized in that The computer program product comprises a computer program, which, when executed by a processor, implements the power distribution method for flexible interconnection of low-voltage substations according to any one of claims 1 to 11.

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