Network loss optimization method considering source load distribution balance degree, memory and electronic device

Abstract

The application discloses a network loss optimization method considering source-load distribution balance degree, a memory and an electronic device, comprising an input layer, a calculation layer, a decision layer, a verification layer and an output layer, the input layer is used for inputting necessary parameters for optimization model calculation, including power distribution network framework present situation, load distribution, and related conditions of to-be-connected distributed photovoltaic; the calculation layer obtains network loss change rate under different distributed photovoltaic connection schemes by calculating input parameters, helps to select a connection scheme with the largest network loss reduction amplitude, and clearly defines the weak link of power distribution network loss problem; the decision layer selects a power distribution network loss optimization strategy according to the weak link of the power distribution network loss; the verification layer compares loss reduction benefits and optimization strategy investment costs to clearly define the feasibility of the optimization strategy scheme; and the output layer outputs an optimal distributed photovoltaic connection scheme and loss reduction optimization strategy, and realizes power distribution network loss optimization based on the influence of distributed photovoltaic connection and line load distribution balance degree on the power distribution network.

Description

[Technical field]

[0001] The present invention relates to the field of power systems, and in particular to a network loss optimization method, a memory and an electronic device taking into account the source-load distribution balance. [Background Technology]

[0002] Combined with national policies and the law of new energy development, power systems with a high proportion of new energy will be the development trend of future power grids. However, the output of distributed photovoltaic power generation is easily affected by weather, seasonal changes, and geographical location, and is intermittent and uncertain. In addition, the power generation fluctuates greatly and is difficult to be as stable as traditional thermal power and hydropower. It affects the voltage distribution. When the capacity incorporated is too large or the location is inappropriate, power reverse flow may occur, making the voltage of some nodes higher than the voltage of the power grid system; it affects the structure of the distribution network. The incorporation of distributed photovoltaics changes the distribution network structure from the original single power source radiation structure to a multi-power source weak ring structure; it affects the direction of the flow. The flow direction of the flow on each branch of the distribution network may change, which will lead to changes in the network loss of the distribution network.

[0003] At the same time, load distribution will also affect the power loss of the distribution network. From the perspective of line load distribution balance, the more concentrated the load on the medium-voltage line is at the head end of the line, the smaller the value of load distribution balance is, and the lower the total power loss of the line is.

[0004] At present, most of the research is mainly based on the impact of distributed photovoltaic access on distribution network losses, without combining the impact of load distribution on distribution network losses to propose corresponding optimization strategies. [Summary of the invention]

[0005] The present invention overcomes the shortcomings of the prior art and provides a network loss optimization method, a memory and an electronic device taking into account the influence of the source-load distribution balance. The model framework of the method includes five parts: an input layer, a calculation layer, a decision layer, a verification layer and an output layer. By taking into account the network loss calculation of the load balance, the optimal distributed photovoltaic access scheme under the condition of minimum network loss is given, and the loss reduction optimization strategy under the optimal access scheme is provided. The strategy mainly provides solutions to the problems of excessive power reverse transmission caused by power grid equipment, light or heavy loads and photovoltaic access.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A network loss optimization method taking into account the balance of source and load distribution, characterized in that: a distribution network loss optimization method is constructed based on the influence of distributed photovoltaic access and line load distribution balance on the distribution network, the method includes:

[0008] S1, input the necessary parameters for optimization model calculation through the input layer;

[0009] S2. Compare the differences between distributed photovoltaic multi-point access and single-point access solutions through the computing layer, calculate the network loss change rate under different distributed photovoltaic access solutions, and select the access solution with the largest network loss reduction;

[0010] S3, according to the calculation results of the weak links of the distribution network loss output by the calculation layer, the corresponding distribution network loss optimization strategy is selected through the decision layer;

[0011] S4. Compare the loss reduction benefits with the investment cost of the optimization strategy and verify the feasibility of the optimization strategy through the verification layer;

[0012] S5. Output the optimal distributed photovoltaic access solution and loss reduction optimization strategy through the output layer.

[0013] The network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that the necessary parameters calculated by the optimization model in S1 include the current parameters of the distribution network grid, load distribution related parameters and distributed photovoltaic related parameters to be connected.

[0014] A network loss optimization method taking into account the influence of source-load distribution balance as described above is characterized in that: the current parameters of the distribution network grid include the number of high-energy consumption distribution transformers, the number of ordinary distribution transformers, the number of energy-saving distribution transformers, the average operating life of distribution transformers and the average operating life of conductors; the load distribution related parameters include the current line loss rate of wired lines, the maximum load of the line, the line load distribution balance value and the line current carrying capacity; the parameters related to the distributed photovoltaics to be connected include the number of distributed photovoltaic projects to be connected, the distributed photovoltaic capacity to be connected, the distributed photovoltaic points to be connected and the load size of the distributed photovoltaic points to be connected.

[0015] The network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that: S2 also includes the weak links of the distribution network loss problem, including

[0016] S21. Calculate the photovoltaic distribution balance of the line:

[0017]

[0018] In formula (1), P PV is the total capacity of distributed photovoltaic access, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, K i is the length of the i-th line segment, and N is the total number of line segments;

[0019] S22, determine the operating status of each distribution transformer connected to the distributed photovoltaic, and record the net load power as P i ′(i=1, 2, ..., N), P i Calculation formula:

[0020] P i ′=P i -P pv-i ·η (2)

[0021] In formula (2), P i is the load connected from the end of the i-th line to the end of the entire line, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, and η is the converter working efficiency;

[0022] P LD is the maximum load of the line, when P i When ′>0, record K i The state of the point distribution transformer is that the distribution transformer is not reversed; when -P LD <P i ′<0, record K i The state of the point distribution transformer is that the distribution transformer reverse transmission line does not reverse transmission; when P i ′<-P LD When i The status of the point distribution transformer is line reverse transmission;

[0023] S23. Determine the distributed photovoltaic access scheme, compare the differences between the distributed photovoltaic multi-point access and single-point access schemes, and first calculate the network loss change rate ε0 under the multi-point access scheme where all distributed photovoltaic projects to be connected are connected nearby:

[0024]

[0025] In formula (3), P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, K i is the length of the i-th line segment, N is the total number of line segments, P LD is the maximum load of the line;

[0026] S24. Calculate the network loss change rate ε1 under the single-point access scheme where all distributed photovoltaic projects to be connected are connected in a converged manner:

[0027]

[0028] In formula (4),

[0029] S25. Among all the distributed photovoltaic projects to be connected, one project is connected nearby separately, and the other projects are connected in a centralized manner. All possibilities are traversed to calculate the network loss change rate under each scheme respectively. Among all the distributed photovoltaic projects to be connected, two projects are connected nearby separately, and the other projects are connected in a centralized manner. All possibilities are traversed to calculate the network loss change rate under each scheme respectively. By analogy, the network loss change rate under all different access schemes is finally formed. By comparing the network loss change rate, the distributed photovoltaic access scheme with the lowest network loss is obtained with the goal of maximizing the network loss reduction.

[0030] S26. Determine whether there are weak links in the grid equipment, including whether the conductor cross-section is too small, whether it is a high-energy consumption distribution transformer, and whether the equipment is aging;

[0031] S27. Determine whether there are weak links in the load, including the light or heavy load of the line and whether the load at the end of the line is too large;

[0032] S28. Determine whether there are weak links in distributed photovoltaics, mainly whether the access capacity of distributed photovoltaics is too large.

[0033] A network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that: the criteria for judging whether there are weak links in the grid equipment in S26 include judging that the conductor cross-section is too small when the maximum load rate of the line is higher than 80% and the conductor current carrying capacity is lower than 400A; judging that it is a high-energy consumption distribution transformer when the fixed loss rate exceeds 1.5%; and judging that the equipment is aged when the average operation period of the equipment exceeds 10 years.

[0034] The network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that: the judgment criteria for whether there is a weak link in the S27 interruption load include: when the maximum load rate is lower than 20%, it is determined that the line is lightly loaded; when the maximum load rate is higher than 80%, it is determined that the line is heavily loaded; when the line load distribution balance K is LD When it is higher than 1.2, the end load is judged to be too large;

[0035]

[0036] In formula (6), P LD is the maximum load of the line, P iLD represents the active power flowing through the i-th line, L i is the length of the th line segment, and N is the total number of line segments.

[0037] The network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that: the criteria for judging whether there are weak links in the distributed photovoltaic system in S28 include: It is determined that the access capacity of distributed photovoltaic is too large, among which KPV is the photovoltaic distribution balance of the line, K LD is the line load distribution balance, P LD is the maximum load of the line.

[0038] The network loss optimization method taking into account the influence of the source-load distribution balance as described above is characterized in that: the calculation method of the feasibility parameter F of the loss reduction optimization measure in S4 is as follows:

[0039]

[0040] In formula (7), A1 is the profit obtained from loss reduction, A2 is the investment cost of the optimization strategy. When F ≥ 1, the optimization strategy is considered feasible; if F < 1, it returns to the decision layer and selects other loss reduction optimization measures.

[0041] A memory, characterized in that the memory is a computer-readable memory and stores a computer program, and when the computer program is executed by a processor, the processor executes the above method.

[0042] An electronic device, characterized in that it comprises a memory and a processor, the memory stores a computer program, and the processor implements the above method when executing the computer program.

[0043] In this case, regarding the definition and calculation method of network loss:

[0044] This project uses power loss to represent network loss. During the research process, power loss is taken as the research object, and the power loss is obtained by integrating the power loss over time. The power loss studied in this project includes transformer loss ΔP T and line loss ΔP L , the research voltage level is 10kV. The transformer loss mainly includes transformer iron loss and copper loss. Iron loss is determined by transformer capacity and no-load loss coefficient, and copper loss is related to transformer current. Transformer parameters are uniformly converted to the 10kV side for calculation; line loss is related to the load distribution on the line, and the power loss of each section of the line needs to be accumulated to obtain the total loss of the line. Transformer loss ΔP T and line loss ΔP L The calculation formula is as follows.

[0045] ΔP T =αS T +3I T 2 R T

[0046]

[0047] Among them, α is the transformer no-load loss coefficient, S T is the rated capacity of the transformer, IT is the current on the 10kV side of the transformer, R T is the total transformer resistance calculated to the 10kV side; I L (l) represents the distribution function of the line current as the length of the main line changes, r L is the resistance per unit length of the line, and L is the total length of the main line of the line.

[0048] The impact of distributed photovoltaics on line losses is mainly reflected in the impact of distributed photovoltaics on transformer current I T And line current I L Distributed photovoltaic power generation will reduce the demand of low-voltage loads for power grid power supply, thereby reducing the transformer current I T , I T When summed up on the line, it will cause the line current I L If power reverse occurs, I T and I L The direction will change. As the access capacity of distributed photovoltaics increases, the reverse current will continue to increase, resulting in increased line losses.

[0049] The definition of load distribution balance in this case is:

[0050] In order to improve the wide adaptability of the research conclusions, this project combines the relationship between network loss and load distribution to define the line load distribution balance degree K LD :

[0051]

[0052] Where P LD is the total line load, P iLD represents the active power flowing through the i-th line, L i is the length of the th line segment, and N is the total number of line segments.

[0053] K LD Represents the ratio of the actual power loss of the line to the power loss of the line when the load is evenly distributed (without considering the effect of reactive power), that is, K LD The larger the value, the greater the actual power loss of the line; K LD The smaller it is, the smaller the actual power loss of the line is; K LD =1, the actual power loss of the line is equal to the power loss of the line when the load is evenly distributed, and the line load can be regarded as evenly distributed in the network loss calculation.

[0054] Regarding the balancing degree of photovoltaic distribution in this case:

[0055] In order to study the distribution of photovoltaic access to the grid, the photovoltaic distribution balance degree K of the line is defined PV :

[0056]

[0057] Where P PV is the total photovoltaic capacity of the access line, P iPV Represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line.

[0058] The impact mechanism of network loss in this case:

[0059] (1) From the comprehensive perspective of medium and low voltage line losses, network losses include not only the variable network losses of medium voltage lines, but also the fixed network losses of low voltage distribution transformers. When the variable network losses are equal to the fixed network losses, the comprehensive line loss rate reaches the lowest value. Therefore, in terms of comprehensively reducing the line loss rate, the variable network losses should be made equal to the fixed network losses as much as possible to achieve the optimal loss reduction effect.

[0060] (2) From the line load distribution balance degree K LD From the perspective of K LD The smaller the line is, the lower the total power loss is. Therefore, the load should be concentrated at the head end of the line as much as possible to reduce the line load distribution balance K LD .

[0061] (3) From the perspective of the single-point access position of distributed photovoltaics, as the access capacity of distributed photovoltaics increases, the single-point access position with the smallest power loss gradually moves from the end of the line to the beginning of the line. When the distribution transformer does not cause reverse transmission, it should be connected to the end of the line. When the distribution transformer reverses but the line does not reverse, it should be connected to the second half of the line. When the first section of the line also reverses, it should be connected to the first half of the line. When the distributed photovoltaic capacity is large enough to cause insufficient line carrying capacity, it should be connected to the substation in a centralized manner.

[0062] (4) From the perspective of distributed photovoltaic single-point access capacity, the access capacity of distributed photovoltaic when the power loss on the line is the minimum When the capacity is greater than or less than this value, the loss reduction effect will be reduced. The distributed photovoltaic access capacity should be as close to this capacity value as possible. When the distributed photovoltaic capacity exceeds 2 times this value, consideration should be given to replacing other access points to avoid increased line network losses.

[0063] (5) The photovoltaic distribution balance degree K of the distributed photovoltaic multi-point access line PV From the perspective of the total capacity of distributed photovoltaic connected to the medium voltage line, the photovoltaic distribution balance degree K corresponding to the minimum power loss is PV And load distribution balance K LD Proportional to; load distribution balance degree K on medium voltage line LD When the power loss is the same, the photovoltaic distribution balance degree K corresponding to the minimum power loss is PVIt is inversely proportional to the square of the distributed photovoltaic access capacity, that is, the larger the distributed photovoltaic access capacity, the closer the distributed photovoltaic distribution should be to the line head end.

[0064] (6) From the perspective of the capacity of distributed photovoltaic multi-point access, the distributed photovoltaic access capacity when the power loss of the entire line is minimum is That is, the distributed photovoltaic access capacity and line load P, photovoltaic distribution balance K that affect power loss PV And load distribution balance K LD Are all related.

[0065] The beneficial effects of the present invention are:

[0066] 1. The present invention improves the economic efficiency of system operation, consumes renewable energy power generation locally, and reduces backflow.

[0067] 2. The optimization of the distributed photovoltaic access solution of the present invention can reduce network losses, improve equipment utilization, and reduce unnecessary investment.

[0068] 3. The present invention explores the weak links in the power grid, proposes an optimization strategy, and improves the power supply reliability of the distribution network. [Drawings]

[0069] Figure 1 Model framework of distribution network loss optimization method. [Specific implementation method]

[0070] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings.

[0071] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the descriptions of "preferred", "sub-preferred", etc. in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "preferred" or "sub-preferred" may explicitly or implicitly include at least one such feature.

[0072] like Figure 1 As shown in the figure, a network loss optimization method taking into account the influence of source-load distribution balance is constructed based on the influence of distributed photovoltaic access and line load distribution balance on the distribution network. The method includes

[0073] S1. Input the necessary parameters for optimization model calculation through the input layer. The input parameters are as follows.

[0074] Table 1 Input parameters

[0075] Input Parameters unit Current status of line loss rate ΔP% ％ <![CDATA[The maximum line load P LD > kW <![CDATA[Line load distribution balance degree K LD > -- <![CDATA[Line current-carrying capacity I M > A Number of distributed photovoltaic projects to be connected N -- <![CDATA[Distributed PV capacity to be connected, P PV-i (i = 1, 2, …, N)]]> kW <![CDATA[Distributed PV connection point to be connected k i (i = 1, 2... N)]]> -- <![CDATA[Load P of the connection point to be connected for distributed photovoltaics i (i = 1, 2... N)]]> kW <![CDATA[The number N of high-energy-consuming distribution transformers M > tower <![CDATA[The number N of ordinary distribution transformers M > mouth <![CDATA[The number N of energy-saving distribution transformers L > mouth <![CDATA[Average operation years Y of distribution transformers T > Year <![CDATA[Average operation years Y of the wire L > Year

[0076] Among them, for hybrid lines, the line current carrying capacity is selected at the position with the smallest cross-section of the main line; when entering parameters, it is necessary to clearly specify the number of photovoltaic projects to be connected, the capacity of each photovoltaic project to be connected and the location of the connection points; high-energy-consuming distribution transformers refer to distribution transformers of models S10 and below, ordinary distribution transformers refer to distribution transformers of models S11, and energy-saving distribution transformers refer to distribution transformers of models S13 and above.

[0077] S2. Compare the differences between distributed photovoltaic multi-point access and single-point access schemes through the computing layer, calculate the network loss change rate under different distributed photovoltaic access schemes, select the access scheme with the largest network loss reduction, and identify the weak links in the distribution network loss problem.

[0078] (1) Calculate the photovoltaic distribution balance of the line

[0079]

[0080] Among them, P PV is the total capacity of distributed photovoltaic access, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, K i is the length of the i-th line segment, and N is the total number of line segments.

[0081] (2) Determine the operating status of each distribution transformer connected to distributed photovoltaic

[0082] The net load power is P i ′(i=1, 2, ..., N), P i The calculation formula is as follows.

[0083] P i ′=P i -P PV-i ·η

[0084] Among them, P i is the load connected from the end of the i-th line to the end of the entire line, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, and η is the working efficiency of the converter.

[0085] P LD is the maximum load of the line, when P i When ′>0, record K i The status of the point distribution transformer is "distribution transformer not reverse transmission"; when -P LD <P i ′<0, record K i The status of the point-to-point distribution transformer is "the distribution transformer reverse transmission line does not reverse transmission"; when P i′<-P LD When i The status of the point distribution transformer is "line reverse transmission".

[0086] (3) Determine the distributed photovoltaic access plan

[0087] By comparing the differences between the multi-point access and single-point access schemes of distributed photovoltaics, we first calculate the network loss change rate ε0 under the multi-point access scheme where all distributed photovoltaic projects to be connected are connected nearby.

[0088]

[0089] Secondly, calculate the network loss change rate ε1 under the single-point access scheme where all distributed photovoltaic projects to be connected are connected in a converged manner.

[0090]

[0091] in,

[0092]

[0093]

[0094] Then, among all the distributed photovoltaic projects to be connected, one project will be connected nearby separately, and the other projects will be connected in a centralized manner. All possibilities will be traversed, and the network loss change rate under each scheme will be calculated respectively; among all the distributed photovoltaic projects to be connected, two projects will be connected nearby separately, and the other projects will be connected in a centralized manner. All possibilities will be traversed, and the network loss change rate under each scheme will be calculated respectively. This process can be deduced by analogy, and the network loss change rate under all different access schemes will eventually be formed. By comparing the network loss change rates, the distributed photovoltaic access scheme with the lowest network loss is obtained with the goal of maximizing the network loss reduction.

[0095] (4) Identify weak links in power grid loss issues

[0096] 1) First determine the device problem

[0097] When the maximum line load rate is higher than 80% and the current carrying capacity of the conductor is lower than 400A, the conductor cross section can be enlarged to increase the current carrying capacity of the line. LD %The calculation method is as follows.

[0098]

[0099] Where U N is the line rated voltage, which is 10kV; is the power factor, take 0.95; I M P is the line current carrying capacity; LD is the maximum load of the line.

[0100] When the fixed loss rate exceeds 1.5%, it is considered that high-energy-consuming distribution transformers have a greater impact on line losses. Cu %The calculation method is as follows.

[0101]

[0102] In the formula, I H % is the percentage of no-load current of high energy consumption distribution transformer, I M % is the percentage of no-load current of ordinary distribution transformer, I L % is the no-load current percentage of energy-saving distribution transformer; N H 、N M 、N L The numbers of three types of distribution transformers are high energy consumption, ordinary type and energy saving type. The reference values ​​of no-load current percentage of each type of distribution transformer are as follows.

[0103] Table 2 Reference values ​​of no-load current percentages for various types of distribution transformers

[0104]

[0105] When the average operating life of equipment exceeds 10 years, it is considered that the equipment is seriously aging and needs to be replaced in time.

[0106] 2) Secondly, determine the load problem

[0107] When the maximum load rate is lower than 20%, it indicates that the line has an underload problem; when the maximum load rate is higher than 80%, it indicates that the line has an overload problem.

[0108] When the line load distribution balance degree K LD When it is higher than 1.2, it means that the end load is too large.

[0109]

[0110] Among them, P LD is the maximum load of the line, P iLD represents the active power flowing through the i-th line, L i is the length of the th line segment, and N is the total number of line segments.

[0111] 3) Final judgment of photovoltaic problems

[0112] From the distributed photovoltaic access capacity P PV Let's see, if This indicates that the penetration rate of distributed photovoltaics is too high, and the overall line loss will increase. The weak links of the grid loss problem and the basis for their determination are as follows.

[0113] Table 3 Weak links in power grid loss problems and their determination basis

[0114]

[0115] S3. According to the calculation results of the weak links of the distribution network loss output by the calculation layer, the decision layer selects the corresponding distribution network loss optimization strategy. The weak links of the power grid loss problem and their optimization strategies are as follows.

[0116] Table 4 Weak links in power grid loss problems and their optimization strategies

[0117]

[0118]

[0119] S4. Based on the comparison between loss reduction benefits and investment costs of optimization strategies, the feasibility of the optimization strategy is clarified through the verification layer. The calculation method of the feasibility parameter F of the loss reduction optimization measure is as follows.

[0120]

[0121] In the formula, A1 is the profit obtained from reducing losses, and A2 is the investment cost of the optimization strategy.

[0122] When F≥1, the optimization strategy is considered feasible. If F<1, it returns to the decision layer and selects other loss reduction optimization measures.

[0123] S5. Output the optimal distributed photovoltaic access solution and loss reduction optimization strategy through the output layer.

[0124] On the other hand, the present invention also discloses a memory, which is a computer-readable memory and stores a computer program. When the computer program is executed by a processor, the processor executes the above-mentioned distribution network loss optimization method taking into account the influence of distributed photovoltaic access and load distribution balance.

[0125] On the other hand, the present invention further discloses an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the distribution network loss optimization method taking into account the influence of distributed photovoltaic access and load distribution balance is implemented.

[0126] Any reference to memory, storage, database or other media used in the embodiments provided in this application may include read-only memory ROM, random access memory RAM, and readable and writable memory FLASH. Among them, read-only memory includes PROM (programmable ROM), EPROM (electrically programmable ROM), EEPROM (electrically erasable programmable ROM); random access memory includes DRAM (dynamic RAM) and SRAM (static RAM); readable and writable memory includes NOR FLASH and NAND FLASH.

[0127] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A network loss optimization method taking into account the balance of source and load distribution, Features: A distribution network loss optimization method is constructed based on the influence of distributed photovoltaic access and line load distribution balance on the distribution network. The method includes S1, input the necessary parameters for optimization model calculation through the input layer; S2. Compare the differences between distributed photovoltaic multi-point access and single-point access solutions through the computing layer, calculate the network loss change rate under different distributed photovoltaic access solutions, and select the access solution with the largest network loss reduction; S3, according to the calculation results of the weak links of the distribution network loss output by the calculation layer, the corresponding distribution network loss optimization strategy is selected through the decision layer; S4. Compare the loss reduction benefits with the investment cost of the optimization strategy and verify the feasibility of the optimization strategy through the verification layer; S5. Output the optimal distributed photovoltaic access solution and loss reduction optimization strategy through the output layer.

2. A network loss optimization method taking into account the source-load distribution balance according to claim 1, Features: The necessary parameters for the optimization model calculation in S1 include the current parameters of the distribution network, the parameters related to the load distribution, and the parameters related to the distributed photovoltaics to be connected.

3. A network loss optimization method taking into account the source-load distribution balance according to claim 2, Features: The current parameters of the distribution network include the number of high-energy consumption distribution transformers, the number of ordinary distribution transformers, the number of energy-saving distribution transformers, the average operating life of distribution transformers and the average operating life of conductors; the load distribution related parameters include the current line loss rate of wired lines, the maximum load of the lines, the line load distribution balance value and the line current carrying capacity; the parameters related to distributed photovoltaics to be connected include the number of distributed photovoltaic projects to be connected, the capacity to be connected, the points to be connected and the load size of the points to be connected.

4. A network loss optimization method taking into account the source-load distribution balance according to claim 1, Features: S2 also includes the weak links of distribution network loss problem, including S21. Calculate the photovoltaic distribution balance of the line: In formula (1), P PV is the total capacity of distributed photovoltaic access, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, K i is the length of the i-th line segment, and N is the total number of line segments; S22. Determine the operating status of each distribution transformer connected to the distributed photovoltaic system, and record the net load power as P′ i (i=1, 2, ..., N), P i Calculation formula: P i ′=P i -P PV-i ·η (2) In formula (2), P i is the load connected from the end of the i-th line to the end of the entire line, P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, and η is the working efficiency of the converter; P LD is the maximum load of the line, when P′ i >0, record K i The state of the point distribution transformer is that the distribution transformer is not reversed; when -P LD <P i When ′<0, record K i The state of the point distribution transformer is that the distribution transformer reverse transmission line does not reverse transmission; when P′ i <-P LD When i The status of the point distribution transformer is line reverse transmission; S23. Determine the distributed photovoltaic access scheme, compare the differences between the distributed photovoltaic multi-point access and single-point access schemes, and first calculate the network loss change rate ε under the multi-point access scheme where all distributed photovoltaic projects to be connected are connected nearby. 0 : In formula (3), P pv-i represents the total photovoltaic capacity connected from the end of the i-th line to the end of the entire line, K i is the length of the i-th line segment, N is the total number of line segments, P LD is the maximum load of the line; S24. Calculate the network loss change rate ε under the single-point access scheme where all distributed photovoltaic projects to be connected are connected in a converged manner 1 : In formula (4), S25. Among all the distributed photovoltaic projects to be connected, one project is connected nearby separately, and the other projects are connected in a centralized manner. All possibilities are traversed to calculate the network loss change rate under each scheme respectively. Among all the distributed photovoltaic projects to be connected, two projects are connected nearby separately, and the other projects are connected in a centralized manner. All possibilities are traversed to calculate the network loss change rate under each scheme respectively. By analogy, the network loss change rate under all different access schemes is finally formed. By comparing the network loss change rate, the distributed photovoltaic access scheme with the lowest network loss is obtained with the goal of maximizing the network loss reduction. S26. Determine whether there are weak links in the grid equipment, including whether the conductor cross-section is too small, whether it is a high-energy consumption distribution transformer, and whether the equipment is aging; S27. Determine whether there are weak links in the load, including the light or heavy load of the line and whether the load at the end of the line is too large; S28. Determine whether there are weak links in distributed photovoltaics, mainly whether the access capacity of distributed photovoltaics is too large.

5. A network loss optimization method taking into account the source-load distribution balance according to claim 4, Features: The criteria for judging whether there are weak links in the grid equipment in S26 include judging that the conductor cross-section is too small when the maximum load rate of the line is higher than 80% and the conductor current carrying capacity is lower than 400A; judging that it is a high-energy consumption distribution transformer when the fixed loss rate exceeds 1.5%; and judging that the equipment is aging when the average operation period of the equipment exceeds 10 years.

6. A network loss optimization method taking into account the source-load distribution balance according to claim 4, Features: The criteria for judging whether there is a weak link in the S27 interruption load include: when the maximum load rate is less than 20%, the line is judged to be lightly loaded; when the maximum load rate is higher than 80%, the line is judged to be overloaded; when the line load distribution balance degree K is LD When it is higher than 1.2, the end load is judged to be too large; In formula (6), P LD is the maximum load of the line, P iLD represents the active power flowing through the i-th line, L i is the length of the th line segment, and N is the total number of line segments.

7. A network loss optimization method taking into account the source-load distribution balance according to claim 4, Features: The criteria for judging whether there are weak links in distributed photovoltaics in S28 include: It is determined that the distributed photovoltaic access capacity is too large, among which K PV is the photovoltaic distribution balance of the line, K LD is the line load distribution balance, P LD is the maximum load of the line.

8. A network loss optimization method taking into account the source-load distribution balance according to claim 1, Features: The calculation method of the feasibility parameter F of the loss reduction optimization measure in S4 is: In formula (7), A 1 A is the income from loss reduction. 2 The investment cost of the optimization strategy is calculated. When F≥1, the optimization strategy is considered feasible. If F<1, it returns to the decision-making layer to select other loss reduction optimization measures.

9. A memory, It is characterized in that The memory is a computer-readable memory and stores a computer program. When the computer program is executed by a processor, the processor executes the method according to any one of claims 1 to 8.

10. An electronic device, Features: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 8 when executing the computer program.

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