Distribution network energy storage configuration method, medium and program product for photovoltaic access

Abstract

The present invention discloses a distribution network energy storage configuration method, medium and program product for photovoltaic access, including: based on the photovoltaic output and user load data obtained in the scenario where the photovoltaic reverse transmission of the distribution network causes line overload, flow calculation is performed, the line with the most serious reverse overload is screened based on the flow calculation result, and the end of the line is selected as the node position of the energy storage configuration; according to the daily transmission power of the line with the most serious reverse overload in the flow calculation result, the maximum reverse overload active power and the daily accumulated reverse overload power of the line with the most serious reverse overload are determined, and the rated power and rated capacity of the energy storage configuration are calculated; the configured energy storage is added to the original distribution network to form a new distribution network, with the lowest line overload current ratio as the goal, a distribution network optimization operation model based on the optimal flow is generated, and the line transmission power distribution under the current energy storage configuration is calculated. The present invention can improve the reliability and operation efficiency of the distribution network.

Description

Technical Field

[0001] The present invention belongs to the technical field of distribution network planning, and specifically relates to a distribution network energy storage configuration method, medium and program product for photovoltaic access. Background Art

[0002] Large-scale access to distributed photovoltaics brings about the problem of reverse overload of distribution network equipment, especially during the midday sunshine period, when electricity is often reversely transmitted to the upper power grid. In addition, the randomness, volatility and intermittency of renewable energy output will affect the safe and stable operation of the system, causing voltage fluctuations and system instability, affecting the safe and stable operation of the distribution network.

[0003] Energy storage, as a key flexibility resource in the new power system, is one of the effective measures to solve the above problems. Its reasonable layout and optimal configuration are of great significance for the local consumption of distributed resources, improving the system regulation capability, and ensuring the safe and efficient operation of the system. The current energy storage configuration scheme usually configures energy storage devices on-site at the photovoltaic reverse transmission node to eliminate the impact of reverse power. However, with the widespread access to distributed photovoltaics, the method of configuring energy storage on-site will lead to a large number of energy storage devices that need to be configured in the distribution network and their dispersed locations, as well as low reliability and operating efficiency of the distribution network. Summary of the invention

[0004] In view of the above problems, the present invention proposes a distribution network energy storage configuration method, medium and program product for photovoltaic access, which can effectively improve the reliability and operation efficiency of the distribution network.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a distribution network energy storage configuration method for photovoltaic access, comprising:

[0007] With the goal of eliminating the reverse overload problem of the line under the current energy storage configuration, the preset energy storage configuration steps are continuously executed to determine the energy storage site selection and capacity determination plan;

[0008] The energy storage configuration step comprises:

[0009] Based on the photovoltaic output and user load data obtained in the scenario where the photovoltaic reverse transmission of the distribution network causes line overload, the power flow calculation is performed, and the line with the most serious reverse overload is selected based on the power flow calculation results, and the end of the line is selected as the node location of the energy storage configuration;

[0010] According to the daily transmission power of the line with the most serious reverse overload in the power flow calculation results, determine the maximum reverse overload active power and daily accumulated reverse overload power of the line with the most serious reverse overload, and calculate the rated power and rated capacity of the energy storage configuration;

[0011] The configured energy storage is added to the original distribution network to form a new distribution network. With the goal of minimizing the line overload current ratio, an optimized distribution network operation model based on the optimal power flow is generated, and the line transmission power distribution under the current energy storage configuration is calculated.

[0012] In combination with the first aspect, optionally, when screening the line with the most serious reverse overload, the calculation formula used is:

[0013] ;

[0014] ;

[0015] in, This is the line with the most serious reverse overload; is the reverse overload active power of line l during period t; is the active power transmitted by line l during period t; is the reverse overload active power limit of line l; is the transmission capacity limit of line l; is the power factor of line l.

[0016] In combination with the first aspect, optionally, when determining the maximum reverse overload active power and the daily accumulated reverse overload power, the calculation formula used is:

[0017] ;

[0018] ;

[0019] in, For Line Maximum reverse overload active power; For Line The daily accumulated reverse overload power, The line for period t Reverse overload active power; The line for period t The transmitted active power, For Line Reverse overload active power limit.

[0020] In combination with the first aspect, optionally, the rated power and rated capacity of the energy storage configuration are calculated using the following formula:

[0021] ;

[0022] ;

[0023] in, and are the rated power and rated capacity of the energy storage respectively; and Both are margin factors.

[0024] In combination with the first aspect, optionally, the method for calculating the line transmission power distribution under the current energy storage configuration includes:

[0025] With the goal of minimizing the line overload current ratio, an optimal operation model of the distribution network based on the optimal power flow is generated;

[0026] The distribution network optimization operation model is solved to determine the line transmission power situation under the current energy storage configuration.

[0027] In combination with the first aspect, optionally, the objective function of the distribution network optimization operation model is expressed as:

[0028] ;

[0029] in, are node numbers. , is the total number of nodes; is the set of line headend nodes with j as the terminal node; The flow through the line during period t The current; For Line Current carrying capacity; The line for period t overload current on.

[0030] In combination with the first aspect, optionally, the constraint conditions of the distribution network optimization operation model include energy storage charging and discharging constraints and distribution network power flow constraints;

[0031] The energy storage charging and discharging constraints include:

[0032] ;

[0033] ;

[0034] ;

[0035] ;

[0036] ;

[0037] ;

[0038] in, and Respectively Energy storage Binary variable for the charge and discharge status flag of the time period; and Respectively Energy storage Charging power and discharging power during the time period; and Respectively The rated power and rated capacity of each energy storage; For the Energy storage The power level during the time period, For the Energy storage The power level during the time period; and Respectively The charging and discharging efficiency of each energy storage; and Respectively The upper and lower limits of the state of charge of each energy storage; For the The initial charge level of each energy storage; For the The power level of each energy storage at the end of the period; is the duration of the time period; is the total number of time periods;

[0039] The power flow constraints of the distribution network include:

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] ;

[0045] ;

[0046] ;

[0047] ;

[0048] in, Node The line end node set of the head end node; To configure on the node Energy storage collection on; For Node The set of distribution transformers on ; and They are the active power and reactive power supplied by the distribution transformer respectively; , For Line resistance and reactance; , They are nodes in time period t Active power and reactive power of load on the and They are nodes in time period t Distributed photovoltaic active power and reactive power on the network; and The line for period t Active power and reactive power on is the node in period t The voltage amplitude; , For Node The upper and lower limits of the voltage amplitude; For the set line Maximum allowable current, and The line for period t The active power and reactive power on is the node in period t The square of the voltage amplitude, is the node in period t The square of the voltage amplitude, The flow through the line during period t The square of the current.

[0049] In combination with the first aspect, optionally, the step of continuously executing preset energy storage configuration steps to determine an energy storage site selection and capacity determination scheme with the goal of preventing the problem of reverse overload of the line under the current energy storage configuration specifically includes:

[0050] If the current energy storage configuration is , is the reverse overload active power of line l in period t, which means that there is no reverse overload on all lines, that is, the current energy storage configuration is sufficient, and the current energy storage configuration scheme is output;

[0051] If the current energy storage configuration is , it means that some lines still have reverse overload problems and need to further increase energy storage, so continue to execute the preset energy storage configuration steps.

[0052] In a second aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the distribution network energy storage configuration method for photovoltaic access as described in any one of the first aspects.

[0053] In a third aspect, the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the distribution network energy storage configuration method for photovoltaic access as described in any one of the first aspects.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The present invention proposes a distribution network energy storage configuration method, medium and program product for reverse overload caused by photovoltaic access. With the goal of minimizing the line overload current ratio, the present invention solves the power reverse transmission and line reverse overload problems caused by the widespread access of distributed photovoltaics to the distribution network through the optimized configuration of energy storage, promotes the consumption of photovoltaics in the distribution network, and realizes the improvement of the reliability and operation efficiency of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor, among which:

[0057] Figure 1 A flow chart of a distribution network energy storage configuration method for reverse overload caused by photovoltaic access provided by the present invention;

[0058] Figure 2 This is the topological structure diagram of the 10kV Tonghu Line 135 node distribution substation test system;

[0059] Figure 3 The daily transmission power curve of each line in the scenario of line overload caused by severe photovoltaic reverse transmission in the distribution test system;

[0060] Figure 4 Configure energy storage charging and discharging output curves for the power distribution test system;

[0061] Figure 5 Configure the energy storage capacity variation curve for the power distribution test system. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 are within the scope of protection of the present invention.

[0063] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0064] Example 1

[0065] An embodiment of the present invention provides a distribution network energy storage configuration method for photovoltaic access, comprising the following steps:

[0066] With the goal of eliminating the reverse overload problem of the line under the current energy storage configuration, the preset energy storage configuration steps are continuously executed to determine the energy storage site selection and capacity determination plan;

[0067] The energy storage configuration step comprises:

[0068] Based on the photovoltaic output and user load data obtained in the scenario where the photovoltaic reverse transmission of the distribution network causes line overload, the power flow calculation is performed, and the line with the most serious reverse overload is selected based on the power flow calculation results, and the end of the line is selected as the node location of the energy storage configuration;

[0069] According to the daily transmission power of the line with the most serious reverse overload in the power flow calculation results, determine the maximum reverse overload active power and daily accumulated reverse overload power of the line with the most serious reverse overload, and calculate the rated power and rated capacity of the energy storage configuration;

[0070] The configured energy storage is added to the original distribution network to form a new distribution network. With the goal of minimizing the line overload current ratio, an optimized distribution network operation model based on the optimal power flow is generated, and the line transmission power distribution under the current energy storage configuration is calculated.

[0071] The distribution network energy storage configuration method for photovoltaic access in the embodiment of the present invention aims to minimize the line overload current ratio. Through the optimized configuration of energy storage, it solves the power reverse transmission and line reverse overload problems caused by the widespread access of distributed photovoltaics to the distribution network, promotes the consumption of photovoltaics in the distribution network, and realizes the improvement of the reliability and operation efficiency of the distribution network.

[0072] In the specific implementation process, Figure 1 As shown, the distribution network energy storage configuration method for photovoltaic access specifically includes the following steps:

[0073] Step S1: for the scenario where the power distribution network photovoltaic power is seriously reversed and causes line overload, power flow calculation is performed based on photovoltaic output and user load data, the line with the most serious power reverse overload is selected, and the end of the line is selected as the node location of the energy storage configuration;

[0074] Step S2, according to the daily transmission power of the line with the most serious reverse overload, determine the maximum reverse overload active power and the daily accumulated reverse overload power of the line, and calculate the rated power and rated capacity of the energy storage configuration;

[0075] Step S3, adding the configured energy storage to the distribution network, establishing a distribution network optimization operation model based on the optimal power flow with the goal of minimizing the line overload current ratio, and determining the final energy storage site selection and sizing plan after iterative optimization and judging whether the line reverse overload problem still exists under the current energy storage configuration.

[0076] In a specific implementation of an embodiment of the present invention, in step S1, for the scenario of severe photovoltaic reverse transmission in the distribution network, a power flow calculation is performed based on photovoltaic output and user load data to determine the transmission power of each line in the distribution network. Based on the transmission power of each line, the line with the largest reverse overload active power is selected as the line with the most severe power reverse overload. When screening the line with the most severe reverse overload, the calculation formula used is:

[0077] (1);

[0078] (2);

[0079] in, This is the line with the most serious reverse overload; is the reverse overload active power of line l during period t; is the active power transmitted by line l during period t; is the reverse overload active power limit of line l; is the transmission capacity limit of line l; is the power factor of line l.

[0080] In a specific implementation of the embodiment of the present invention, in step S1, the daily transmission power data of the line with the most serious reverse overload can be obtained from the power flow calculation result. Based on this, the calculation formula used to determine the maximum reverse overload active power and the daily accumulated reverse overload power is:

[0081] (3);

[0082] (4);

[0083] in, For Line Maximum reverse overload active power; For Line The daily accumulated reverse overload power, The line for period t Reverse overload active power; The line for period t The transmitted active power (obtained from the power flow calculation results), For Line The reverse overload active power limit is a known parameter.

[0084] In a specific implementation of the embodiment of the present invention, based on the maximum reverse overload active power of the line with the most serious reverse overload and the daily accumulated reverse overload power, the rated power and rated capacity of the energy storage configuration are calculated using the following formula:

[0085] (5);

[0086] (6);

[0087] in, and are the rated power and rated capacity of the energy storage respectively; and Both are margin factors.

[0088] In a specific implementation of the embodiment of the present invention, the method for calculating the line transmission power distribution under the current energy storage configuration includes:

[0089] With the goal of minimizing the line overload current ratio, an optimal operation model of the distribution network based on the optimal power flow is generated;

[0090] The distribution network optimization operation model is solved to determine the line transmission power situation under the current energy storage configuration.

[0091] In a specific implementation of the embodiment of the present invention, the method for calculating the line transmission power distribution under the current energy storage configuration includes the following steps:

[0092] Step S31, establish the objective function of the distribution network optimization operation model, considering that severe photovoltaic reverse transmission will cause reverse overload of the line, thereby causing the current flowing through the line to exceed the current carrying capacity limit. For this reason, the objective function is set to the lowest line overload current ratio. Specifically: the expression of the objective function of the distribution network optimization operation model is:

[0093] (7);

[0094] in, are node numbers. ; is the set of line headend nodes with j as the terminal node; The flow through the line during period t The current; For Line Current carrying capacity; The line for period t overload current on.

[0095] Step S32: establishing constraints of a power grid optimization operation model, wherein the constraints of the distribution network optimization operation model include energy storage charging and discharging constraints and distribution network flow constraints;

[0096] The energy storage charging and discharging constraints include:

[0097] (8) ;

[0098] (9) ;

[0099] (10) ;

[0100] (11) ;

[0101] (12) ;

[0102] (13) ;

[0103] in, and Respectively Energy storage Binary variable for the charge and discharge status flag of the time period; and Respectively Energy storage Charging power and discharging power during the time period; and Respectively The rated power and rated capacity of each energy storage; For the Energy storage The power level during the time period, For the Energy storage The power level during the time period; and Respectively The charging and discharging efficiency of each energy storage; and Respectively The upper and lower limits of the state of charge of each energy storage; For the The initial charge level of each energy storage; For the The power level of each energy storage at the end of the period; is the duration of the time period; is the total number of time periods;

[0104] The power flow constraints of the distribution network include:

[0105] (14) ;

[0106] (15) ;

[0107] (16) ;

[0108] (17) ;

[0109] (18) ;

[0110] (19) ;

[0111] In the formula, is the set of line end nodes with j as the head end node; is the energy storage set configured on node j; is the set of distribution transformers on node j; and They are the active power and reactive power supplied by the distribution transformer respectively; , is the resistance and reactance of line ij; , are the active power and reactive power of the load on node j in period t respectively; and are the distributed photovoltaic active power and reactive power at node j in period t respectively; and is the active power and reactive power on line ij during period t; is the voltage amplitude of node j at time period t; , are the upper and lower limits of the voltage amplitude at node j; The maximum allowable current of the set line ij can be set to 2~4 times the line current carrying capacity considering the impact of severe reverse transmission of photovoltaic power.

[0112] Step S33, converting the power flow constraints of the distribution network, generating an optimal power flow distribution network optimization operation model, solving the optimal power flow distribution network optimization operation model, and determining the line transmission power under the current energy storage configuration;

[0113] Perform convex relaxation on the power flow constraint and define the intermediate variables:

[0114] (20) ;

[0115] (twenty one) ;

[0116] Then equations (14)-(19) can be transformed into:

[0117] (twenty two) ;

[0118] (twenty three) ;

[0119] (twenty four) ;

[0120] (25) ;

[0121] (26) ;

[0122] (27) ;

[0123] There are still nonlinear terms in equation (26), so the quadratic equations of line current, voltage and transmission power are further relaxed and transformed into a rotated second-order cone form, as follows:

[0124] (28) ;

[0125] Formula (28) can be further transformed into a standard second-order cone form, namely:

[0126] (29) ;

[0127] in, Node The line end node set of the head end node; To configure on the node Energy storage collection on; For Node The set of distribution transformers on ; and They are the active power and reactive power supplied by the distribution transformer respectively; , For Line resistance and reactance; , They are nodes in time period t Active power and reactive power of load on the and They are nodes in time period t Distributed photovoltaic active power and reactive power on the network; and The line for period t Active power and reactive power on is the node in period t The voltage amplitude; , For Node The upper and lower limits of the voltage amplitude; For the set line Maximum allowable current, and The line for period t The active power and reactive power on is the node in period t The square of the voltage amplitude, is the node in period t The square of the voltage amplitude, The flow through the line during period t The square of the current.

[0128] According to equations (7)-(13), (22)-(25), (27) and (29), the optimal operation model of the distribution network based on the optimal power flow can be generated with the goal of minimizing the line overload current ratio. After solving it with an optimization algorithm or a solver such as Gurobi or Cplex, the transmission power of the distribution network line under the current energy storage configuration can be obtained.

[0129] S34. If the current energy storage configuration is , is the reverse overload active power of line l in period t, which means that there is no reverse overload on all lines, that is, the current energy storage configuration is sufficient, and the current energy storage configuration scheme is output;

[0130] If the current energy storage configuration is , it means that some lines still have reverse overload problems and need to further increase energy storage, then continue to execute the preset energy storage configuration steps, that is, and determine the node location, rated power and rated capacity of the newly added energy storage according to equations (1)-(7). After the new energy storage is added, the configured energy storage is added to the original distribution network to form a new distribution network, with the goal of minimizing the line overload current ratio, generating a distribution network optimization operation model based on the optimal power flow, and calculating the line transmission power distribution under the current energy storage configuration, until all lines have no reverse overload. In this way, the final distribution network energy storage site selection and capacity determination plan can be determined.

[0131] The 10kV Tonghu Line 135 node distribution substation is used as the test system. Figure 2 As shown in Figure 1, node 1 is the distribution transformer power supply node. The base values ​​of the distribution test system capacity and voltage are 100MVA and 10kV respectively, and the relevant parameters are shown in Table 1. The daily transmission power curve of each line under the severe photovoltaic reverse transmission scenario is shown in Figure 1. Figure 3 shown.

[0132] Table 1 Parameter settings for power distribution test system

[0133]

[0134] After iterative optimization, the distribution test system is equipped with 10.70MW / 57.47MWh energy storage at 7 nodes. The specific configuration is shown in Table 2. The charging and discharging power curves and power change curves of each energy storage are shown in Figure 4 and Figure 5 shown.

[0135] Table 2 Energy storage configuration results

[0136] Node location Rated power (MW) Rated capacity (MWh) 3 4.83 32.93 10 1.13 5.46 14 1.26 5.63 17 1.15 4.88 18 1.08 4.43 24 0.94 3.58 40 0.30 0.57

[0137] Example 2

[0138] In an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the distribution network energy storage configuration method for photovoltaic access described in any one of Embodiment 1 is implemented.

[0139] Example 3

[0140] In an embodiment of the present invention, a computer program product is provided, including a computer program / instruction, which, when executed by a processor, implements the distribution network energy storage configuration method for photovoltaic access described in any one of Embodiment 1.

[0141] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0142] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, 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, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0143] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0144] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0145] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

[0146] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A distribution network energy storage configuration method for photovoltaic access, characterized in that: include: With the goal of eliminating the reverse overload problem of the line under the current energy storage configuration, the preset energy storage configuration steps are continuously executed to determine the energy storage site selection and capacity determination plan; The energy storage configuration step comprises: Based on the photovoltaic output and user load data obtained in the scenario where the photovoltaic reverse transmission of the distribution network causes line overload, the power flow calculation is performed, and the line with the most serious reverse overload is selected based on the power flow calculation results, and the end of the line is selected as the node location of the energy storage configuration; According to the daily transmission power of the line with the most serious reverse overload in the power flow calculation results, determine the maximum reverse overload active power and daily accumulated reverse overload power of the line with the most serious reverse overload, and calculate the rated power and rated capacity of the energy storage configuration; Add the configured energy storage to the original distribution network to form a new distribution network. With the goal of minimizing the line overload current ratio, generate an optimal distribution network operation model based on the optimal power flow, and calculate the line transmission power distribution under the current energy storage configuration; The expression of the objective function of the distribution network optimization operation model is: Where i and j are node numbers, i,j=1,2,...,N b , N b is the total number of nodes; j I is the set of nodes at the beginning of the line with j as the terminal node; ij,t is the current flowing through line ij during period t; is the current carrying capacity of line ij; is the overload current on line ij during period t; The constraints of the distribution network optimization operation model include energy storage charging and discharging constraints and distribution network flow constraints; The energy storage charging and discharging constraints include: AND k,0 =And k,T ; in, and They are binary variables for the charge and discharge status flags of the kth energy storage period t; and are the charging power and discharging power of the kth energy storage period t respectively; and are the rated power and rated capacity of the kth energy storage respectively; E k,t is the power level of the kth energy storage period t, E k,t-1 is the power level of the kth energy storage period t-1; and are the charging efficiency and discharging efficiency of the kth energy storage, respectively; and are the upper and lower limits of the state of charge of the kth energy storage; E k,0 is the initial power level of the kth energy storage; E k,T is the power level of the kth energy storage at the end of the period; Δt is the period length; T is the total number of periods; The power flow constraints of the distribution network include: Among them, Ω j is the set of line end nodes with node j as the head node; j is the energy storage set configured on node j; j is the set of distribution transformers on node j; and are the active power and reactive power supplied by the distribution transformer respectively; R ij , X ij is the resistance and reactance of line ij; are the active power and reactive power of the load on node j in period t respectively; and are the distributed photovoltaic active power and reactive power at node j in period t respectively; P ij,t and Q ij,t is the active power and reactive power on line ij during period t; V j,t is the voltage amplitude of node j at time period t; are the upper and lower limits of the voltage amplitude at node j; is the maximum current allowed by the set line ij, P jm,t and Q jm,t is the active power and reactive power on line jm during period t, is the square value of the voltage amplitude at node i during period t, is the square value of the voltage amplitude at node j during period t, It is the square value of the current flowing through line ij during period t.

2. According to a method for configuring energy storage in a distribution network for photovoltaic access according to claim 1, it is characterized in that: When screening the line with the most serious reverse overload, the calculation formula used is: Among them, l* is the line with the most serious reverse overload; is the reverse overload active power of line l during period t; P l,t is the active power transmitted by line l during period t; P l lim is the reverse overload active power limit of line l; is the transmission capacity limit of line l; is the power factor of line l.

3. The method for configuring energy storage in a distribution network for photovoltaic access according to claim 1, characterized in that: The calculation formula used to determine the maximum reverse overload active power and the daily accumulated reverse overload power is: in, is the maximum reverse overload active power of line l*; is the daily accumulated reverse overload power of line l*, is the reverse overload active power of line l* during period t; P l*,t is the active power transmitted by line l* during period t, is the reverse overload active power limit of line l*.

4. A distribution network energy storage configuration method for photovoltaic access according to claim 3, characterized in that: The rated power and rated capacity of the energy storage configuration are calculated using the following formula: Among them, P ES and E ES are the rated power and rated capacity of the energy storage respectively; α and β are both margin coefficients.

5. The method for configuring energy storage in a distribution network for photovoltaic access according to claim 1, characterized in that: The method for calculating the line transmission power distribution under the current energy storage configuration includes: With the goal of minimizing the line overload current ratio, an optimal operation model of the distribution network based on the optimal power flow is generated; The distribution network optimization operation model is solved to determine the line transmission power situation under the current energy storage configuration.

6. A distribution network energy storage configuration method for photovoltaic access according to claim 5, characterized in that: The goal is to ensure that there is no reverse overload problem in the line under the current energy storage configuration, and to continuously execute the preset energy storage configuration steps to determine the energy storage site selection and capacity determination plan, which specifically includes: If the current energy storage configuration is is the reverse overload active power of line l in period t, it means that there is no reverse overload on all lines, that is, the current energy storage configuration is sufficient, and the current energy storage configuration scheme is output; if the current energy storage configuration is This means that some lines still have reverse overload problems and need to further increase energy storage, so continue to execute the preset energy storage configuration steps.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the distribution network energy storage configuration method for photovoltaic access as described in any one of claims 1 to 6 is implemented.

8. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the distribution network energy storage configuration method for photovoltaic access described in any one of claims 1 to 6 is implemented.

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