A comprehensive control system for distributed photovoltaic power grid connection

Abstract

The present invention relates to the technical field of grid-connected control, and specifically discloses a comprehensive control system for grid-connected distributed photovoltaic power sources, including: a partitioning module: planning a target area for each transformer according to the location information of the transformer and a preset power threshold of the transformer; a power prediction module: drawing a target curve according to the redundant power of the photovoltaic power source acquired in real time during a monitoring period; determining the average redundant power and determining a reference line according to the average redundant power, and determining an excess curve and a shortage curve according to the positional relationship between the reference line and the target curve; calculating a deviation coefficient, and determining the expected power of the photovoltaic power source according to the deviation coefficient; a control module: determining a target transformer of the photovoltaic power source in the target area according to the expected power, and the photovoltaic power source is connected to the grid through the target transformer when connected to the grid. The present invention can adjust the transformer connected when different photovoltaic power sources are connected to the grid, and ensure the normal operation of the transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of grid-connected control, and in particular to a comprehensive control system for grid-connected distributed photovoltaic power sources. Background Art

[0002] Distributed photovoltaic power grid connection refers to converting the electricity generated by the distributed photovoltaic power generation system into AC power with the same frequency and voltage level as the public power grid through power transformers and inverters, and then directly transmitting this electricity to the public power grid. After grid connection, the power of the photovoltaic system can support its own electricity demand, and the remaining power can be fed back to the public power grid.

[0003] When distributed photovoltaic power sources are connected to the grid, their voltage level and frequency need to be adjusted through transformers to ensure the stability and reliability of the power system. With the advancement of photovoltaic technology and the reduction of costs, the number of distributed photovoltaic power sources has gradually increased, which has led to an increasing demand for photovoltaic power grid connection. However, due to the upper limit of the processing capacity of the transformer, too many distributed photovoltaic power sources are concentrated through one transformer for grid connection, which may cause the transformer to be overloaded, thereby affecting its normal operation. Based on this, a comprehensive control system for distributed photovoltaic power grid connection is provided to adjust the transformers connected when different photovoltaic power sources are connected to the grid to ensure the normal operation of the transformer. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive control system for distributed photovoltaic power grid connection to solve the following technical problems:

[0005] When distributed photovoltaic power sources are connected to the grid, their voltage level and frequency need to be adjusted through transformers to ensure the stability and reliability of the power system. With the advancement of photovoltaic technology and the reduction of costs, the number of distributed photovoltaic power sources has gradually increased, which has led to an increasing demand for photovoltaic power sources to be connected to the grid. However, since there is a certain upper limit to the processing capacity of the transformer, too many distributed photovoltaic power sources concentrated on one transformer for grid connection may cause the transformer to be overloaded, thereby affecting its normal operation.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A comprehensive control system for distributed photovoltaic power grid connection, comprising:

[0008] Partitioning module: determine the monitoring area, obtain the location information of the transformer in the monitoring area, and plan the target area of ​​each transformer according to the location information of the transformer and the preset power threshold Pyz of the transformer;

[0009] Power prediction module: set a monitoring period T, obtain the redundant power of the photovoltaic power source in real time during the monitoring period, and draw a curve f(t) of the redundant power changing with time, and use it as the target curve, and the redundant power is the difference between the generated power of the photovoltaic power source and the power consumed by the user;

[0010] Calculating the average redundant power , and take the straight line passing through (0, Ppj) and parallel to the x-axis as the reference line, and take the intersection of the reference line and the target curve as the reference point, when the target curve between two adjacent reference points is above the reference line, it is taken as the excess curve, and when the target curve between two adjacent reference points is below the reference line, it is taken as the scarcity curve;

[0011] Calculate the deviation coefficient K, and when the deviation coefficient K ≥ K', remove the deviation curve corresponding to the maximum deviation max (CJH), K' represents the preset deviation coefficient threshold, the deviation curve includes the excess curve and the shortage curve, CJH = (C 1 , C 2 , …, C N1 , C 1 ', C 2 ', ..., C N2 '), where C N1 =max(g N1 (t)-Ppj,g N1 (t) represents the N1th excess curve, C N2 '=|min(h N2 (t))-Ppj|,h N2 (t) represents the N2th scarcity curve;

[0012] Repeat the above steps and calculate the average redundant power and the deviation coefficient K until the deviation coefficient K is less than K' after removing the maximum deviation, and take the average redundant power at this time as the expected power PYQ of the photovoltaic power source;

[0013] Control module: determine the target transformer of the photovoltaic power source in the target area according to the expected power, and the photovoltaic power source is connected to the grid through the target transformer when connected to the grid.

[0014] As a further solution of the present invention: in the power prediction module, the process of calculating the deviation coefficient K specifically includes:

[0015] The deviation coefficient K is calculated by a formula, wherein the formula specifically includes:

[0016] ;

[0017] Where ε represents the preset correction coefficient, N=N1+N2, t iIndicates the time length corresponding to the i-th deviation curve.

[0018] As a further solution of the present invention: in the control module, the process of determining the target transformer of the photovoltaic power source in the target area according to the expected power specifically includes:

[0019] Determine the target area A' corresponding to transformer A, and calculate the total expected power Ptot of the photovoltaic power source in the target area A';

[0020] When Ptot≤Pyz A When the photovoltaic power source in the target area A takes transformer A as the target transformer, Pyz A Indicates the power threshold of transformer A;

[0021] When Ptot>Pyz A , perform the following steps:

[0022] The photovoltaic power sources in the target area A' are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the first ranking is obtained;

[0023] Starting from the first photovoltaic power source in the first ranking, m photovoltaic power sources are selected in sequence until m meets the following constraints:

[0024] ∑m≥Pcz;

[0025] ∑(m-1)<Pcz;

[0026] Where Pcz = Ptot - Pyz A , ∑m represents the sum of the expected powers of the first m photovoltaic power sources, ∑(m-1) represents the sum of the expected powers of the first m-1 photovoltaic power sources, and transformer A is taken as the target transformer for photovoltaic power sources whose sorting position belongs to [m+1, M], and M represents the total number of photovoltaic power sources in the target area A'.

[0027] As a further solution of the present invention: the process of determining the target transformer of the photovoltaic power source in the target area according to the expected power also includes:

[0028] The photovoltaic power sources whose sorting positions in the first sorting corresponding to all target areas belong to [1, m] are taken as target power sources, and the target power sources are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the second sorting is obtained;

[0029] Determine the residual power PSY=Pcz-∑m of the transformer in the target area, and when the residual power PSY≥0, use the corresponding transformer as a pending transformer;

[0030] Determine the undetermined transformer Y' that is closest to the target power source Y that is at the first place in the second sorting, and perform the following steps:

[0031] When PYQ Y ≤PSY Y' When the transformer Y' to be determined is used as the target transformer of the target power source Y, PYQ Y Indicates the expected power of the target power source Y, PSY Y' Represents the remaining power of the pending transformer Y', and updates the remaining power of the pending transformer Y' PSY = PSY Y' -PYQ Y ;

[0032] When PYQ Y >PSY Y' When the target transformer Y' is removed, the target transformer closest to the target power source Y is determined again, and the above steps are repeated until the target transformer of the target power source Y is determined.

[0033] As a further solution of the present invention: in the process of determining the first ranking, when there are two photovoltaic power sources with the same deviation coefficient, they are ranked according to the corresponding expected power, and the larger the expected power, the lower the ranking.

[0034] As a further solution of the present invention: the process of determining the transformer to be determined further includes the following steps:

[0035] The minimum value PYQmin of the expected power of the target power source is obtained, and when the remaining power PSY<PYQmin, the corresponding transformer is no longer used as a pending transformer.

[0036] As a further solution of the present invention: in the partition module, the process of planning the target area of ​​each transformer according to the location information of the transformer specifically includes:

[0037] Obtain the location information of the transformer in the preset monitoring area, draw a circle with the location of the transformer as the center and the preset radius R to obtain the initial area;

[0038] The number A of photovoltaic power sources in the initial area is obtained, and the transformer power threshold Pyz=a*Pys corresponding to the initial area is determined, where Pys represents the maximum power of the transformer and a is a first preset coefficient. The correction radius r=μ(a*Pys / A) is calculated, where μ represents a second preset coefficient. The initial area corresponding to the transformer is determined again according to the correction radius and is used as the target area.

[0039] As a further solution of the present invention: the partition module further includes the following steps:

[0040] Generate the target region set and DJH=(S1,S2,…,Sn), Sn represents the nth target region,

[0041] When DJH∪D≠D, the correction radius of the initial area is adjusted synchronously until the correction radius is r' after a certain adjustment, and DJH∪D=D appears for the first time when the correction radius is r', where D represents the monitoring area, and the target area is determined according to the correction radius r'.

[0042] Beneficial effects of the present invention: In the present invention, firstly, the target area of ​​each transformer is planned according to the location information of the transformer and the preset power threshold of the transformer; it can be understood that by determining the target area of ​​the transformer, the photovoltaic power source in the target area will give priority to the corresponding transformer for grid connection. In the transmission process from the photovoltaic power source to the transformer, the longer the transmission distance, the greater the power loss. By determining the target area, this situation can be avoided as much as possible; then, considering that the total power of the photovoltaic power source in the target area may exceed the power threshold of the transformer, at this time, if all the photovoltaic power sources in the target area are grid-connected through the transformer corresponding to the target area, it will exceed the upper limit of the transformer's processing capacity, causing safety hazards. Therefore, it is necessary to predict the power generation power of the photovoltaic power source instead of directly The reasons for using the average redundant power as the expected power of the photovoltaic power source include: although the average redundant power can reflect the average power that the photovoltaic power source can be connected to the grid, the average redundant power may be affected by abnormal conditions such as extreme values, so the deviation coefficient is calculated to measure the credibility of the average redundant power. When the deviation coefficient is large, it means that the credibility is low, so the maximum deviation is removed and the average redundant power and the deviation coefficient are calculated again until the credibility of the average redundant power reaches the preset range. The specific value of K' and the length of T can be set by experience; finally, the target transformer of the photovoltaic power source in the target area is determined according to the expected power, and the photovoltaic power source is connected to the grid through the target transformer when connected to the grid, thereby avoiding too many photovoltaic power sources from being connected to the grid through the same transformer, resulting in safety accidents. The present invention can adjust the transformer connected when different photovoltaic power sources are connected to the grid to ensure the normal operation of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below in conjunction with the accompanying drawings.

[0044] Figure 1 It is a flow chart of a comprehensive control system for grid-connected distributed photovoltaic power sources according to the present invention. DETAILED DESCRIPTION

[0045] 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.

[0046] See also Figure 1 As shown, the present invention is a comprehensive control system for distributed photovoltaic power grid connection, including:

[0047] Partitioning module: determine the monitoring area, obtain the location information of the transformer in the monitoring area, and plan the target area of ​​each transformer according to the location information of the transformer and the preset power threshold Pyz of the transformer;

[0048] Power prediction module: set a monitoring period T, obtain the redundant power of the photovoltaic power source in real time during the monitoring period, and draw a curve f(t) of the redundant power changing with time, and use it as the target curve, and the redundant power is the difference between the generated power of the photovoltaic power source and the power consumed by the user;

[0049] Calculating the average redundant power , and take the straight line passing through (0, Ppj) and parallel to the x-axis as the reference line, and take the intersection of the reference line and the target curve as the reference point, when the target curve between two adjacent reference points is above the reference line, it is taken as the excess curve, and when the target curve between two adjacent reference points is below the reference line, it is taken as the scarcity curve;

[0050] Calculate the deviation coefficient K, and when the deviation coefficient K ≥ K', remove the deviation curve corresponding to the maximum deviation max (CJH), K' represents the preset deviation coefficient threshold, the deviation curve includes the excess curve and the shortage curve, CJH = (C 1 , C 2 , …, C N1 , C 1 ', C 2 ', ..., C N2 '), where C N1 =max(g N1 (t)-Ppj,g N1 (t) represents the N1th excess curve, C N2 '=|min(h N2 (t))-Ppj|,h N2 (t) represents the N2th scarcity curve;

[0051] Repeat the above steps and calculate the average redundant power and the deviation coefficient K until the deviation coefficient K is less than K' after removing the maximum deviation, and take the average redundant power at this time as the expected power PYQ of the photovoltaic power source;

[0052] Control module: determine the target transformer of the photovoltaic power source in the target area according to the expected power, and the photovoltaic power source is connected to the grid through the target transformer when connected to the grid.

[0053] It should be noted that first, the target area of ​​each transformer is planned according to the location information of the transformer and the preset power threshold of the transformer; it can be understood that by determining the target area of ​​the transformer, the photovoltaic power source in the target area will give priority to the corresponding transformer for grid connection. In the transmission process from the photovoltaic power source to the transformer, the longer the transmission distance, the greater the power loss. By determining the target area, this situation can be avoided as much as possible; then, considering that the total power of the photovoltaic power sources in the target area may exceed the power threshold of the transformer, at this time, if all the photovoltaic power sources in the target area are connected to the grid through the transformer corresponding to the target area, it will exceed the upper limit of the transformer's processing capacity, causing safety hazards. Therefore, it is necessary to predict the power generation power of the photovoltaic power source instead of directly using the average The reasons why redundant power is used as the expected power of photovoltaic power sources include: although the average redundant power can reflect the average grid-connected power of photovoltaic power sources, the average redundant power may be affected by abnormal conditions such as extreme values. Therefore, the deviation coefficient is calculated to measure the credibility of the average redundant power. When the deviation coefficient is large, it means that the credibility is low. Therefore, the maximum deviation is removed and the average redundant power and the deviation coefficient are calculated again until the credibility of the average redundant power reaches the preset range. The specific value of K' and the length of T can be set by experience; finally, the target transformer of the photovoltaic power source in the target area is determined according to the expected power. The photovoltaic power source is connected to the grid through the target transformer when it is connected to the grid, thereby avoiding too many photovoltaic power sources being connected to the grid through the same transformer, resulting in safety accidents.

[0054] In another preferred embodiment of the present invention, in the power prediction module, the process of calculating the deviation coefficient K specifically includes:

[0055] The deviation coefficient K is calculated by a formula, wherein the formula specifically includes:

[0056] ;

[0057] Where ε represents the preset correction coefficient, N=N1+N2, t i Indicates the time length corresponding to the i-th deviation curve.

[0058] It is worth noting that The larger it is, the higher the degree of deviation towards the scarcity curve and the principle average redundant power, which means that the possibility of the power in the next monitoring period being the average redundant power is smaller. Therefore, the deviation degree coefficient needs to be increased, that is, the credibility of the average redundant power is reduced. The relationship between the other parameters and the deviation coefficient is analogous to the above idea, and no further elaboration is given here. ε can be set by experience.

[0059] In another preferred embodiment of the present invention, in the control module, the process of determining the target transformer of the photovoltaic power source in the target area according to the expected power specifically includes:

[0060] Determine the target area A' corresponding to transformer A, and calculate the total expected power Ptot of the photovoltaic power source in the target area A';

[0061] When Ptot≤Pyz A When the photovoltaic power source in the target area A takes transformer A as the target transformer, Pyz A Indicates the power threshold of transformer A;

[0062] When Ptot>Pyz A , perform the following steps:

[0063] The photovoltaic power sources in the target area A' are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the first ranking is obtained;

[0064] Starting from the first photovoltaic power source in the first ranking, m photovoltaic power sources are selected in sequence until m meets the following constraints:

[0065] ∑m≥Pcz;

[0066] ∑(m-1)<Pcz;

[0067] Where Pcz = Ptot - Pyz A , ∑m represents the sum of the expected powers of the first m photovoltaic power sources, ∑(m-1) represents the sum of the expected powers of the first m-1 photovoltaic power sources, and transformer A is taken as the target transformer for photovoltaic power sources whose sorting position belongs to [m+1, M], and M represents the total number of photovoltaic power sources in the target area A'.

[0068] It should be noted that when Ptot≤Pyz A When Ptot>Pyz, it means that all photovoltaic power sources in the target area will not exceed the processing upper limit of the transformer when they are connected to the grid through transformer A. Therefore, the photovoltaic power sources in the target area A' can be directly connected to the grid through transformer A. AWhen , it means that the total expected power exceeds the upper limit of the processing capacity of transformer A. Therefore, m photovoltaic power sources are selected from them for grid connection through transformer A. The reasons for selection based on the deviation coefficient include: the deviation coefficient reflects the credibility of the expected power. The larger the deviation coefficient, the lower the credibility. Therefore, photovoltaic power sources with larger deviation coefficients are removed first to avoid a sudden increase in the power of the photovoltaic power source, which causes the actual total power to exceed the upper limit of the processing capacity of the transformer and cause a safety accident.

[0069] In a preferred situation of this embodiment, the process of determining the target transformer of the photovoltaic power source in the target area according to the expected power further includes:

[0070] The photovoltaic power sources whose sorting positions in the first sorting corresponding to all target areas belong to [1, m] are taken as target power sources, and the target power sources are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the second sorting is obtained;

[0071] Determine the residual power PSY=Pcz-∑m of the transformer in the target area, and when the residual power PSY≥0, use the corresponding transformer as a pending transformer;

[0072] Determine the undetermined transformer Y' that is closest to the target power source Y that is at the first place in the second sorting, and perform the following steps:

[0073] When PYQ Y ≤PSY Y' When the transformer Y' to be determined is used as the target transformer of the target power source Y, PYQ Y Indicates the expected power of the target power source Y, PSY Y' Represents the remaining power of the pending transformer Y', and updates the remaining power of the pending transformer Y' PSY = PSY Y' -PYQ Y ;

[0074] When PYQ Y >PSY Y' When the target transformer Y' is removed, the target transformer closest to the target power source Y is determined again, and the above steps are repeated until the target transformer of the target power source Y is determined.

[0075] It should be noted that the target power source is determined, and the transformer selected when the target power source is connected to the grid is determined again based on the expected power of the target power source and the remaining power of the pending transformer to maximize the overall economic benefits. At the same time, the pending transformer is selected according to the distance, which can minimize the increase in power loss caused by the long transmission distance, avoid the waste of electricity of the photovoltaic power source, and the occurrence of safety accidents of the transformer; in the above steps, if the expected power of the target power source Y exceeds the remaining power of all the pending transformers, a command is sent to prohibit it from being connected to the grid, so as to avoid safety accidents of the transformer caused by forced grid connection.

[0076] In another preferred embodiment of the present invention, in the process of determining the first ranking, when there are two photovoltaic power sources with the same deviation coefficient, they are ranked according to the corresponding expected power, and the larger the expected power, the lower the ranking.

[0077] In another preferred embodiment of the present invention, the process of determining the transformer to be determined further includes the following steps:

[0078] The minimum value PYQmin of the expected power of the target power source is obtained, and when the remaining power PSY<PYQmin, the corresponding transformer is no longer used as a pending transformer.

[0079] It is understandable that the remaining power of the pending transformer is less than the minimum value of the expected power of the target power source, indicating that all target power sources cannot be connected to the grid through the pending transformer. Therefore, it is no longer used as a pending transformer, reducing the amount of data during analysis and processing.

[0080] In another preferred embodiment of the present invention, in the partitioning module, the process of planning the target area of ​​each transformer according to the location information of the transformer specifically includes:

[0081] Obtain the location information of the transformer in the preset monitoring area, draw a circle with the location of the transformer as the center and the preset radius R to obtain the initial area;

[0082] The number A of photovoltaic power sources in the initial area is obtained, and the transformer power threshold Pyz=a*Pys corresponding to the initial area is determined, where Pys represents the maximum power of the transformer and a is a first preset coefficient. The correction radius r=μ(a*Pys / A) is calculated, where μ represents a second preset coefficient. The initial area corresponding to the transformer is determined again according to the correction radius and is used as the target area.

[0083] It is worth noting that the power thresholds of different transformers are not necessarily the same. The larger the power threshold, the more photovoltaic power sources can be connected to the grid through it, and the larger the correction radius should be. In actual situations, the transformer needs to process not only the electricity from photovoltaic power sources, but also other sources such as wind power generation. Therefore, the power threshold that can be used to process the electricity from photovoltaic power sources is determined by a*Pys, and a can be set by experience.

[0084] In another preferred embodiment of the present invention, the partitioning module further includes the following steps:

[0085] Generate the target region set and DJH=(S1,S2,…,Sn), Sn represents the nth target region,

[0086] When DJH∪D≠D, the correction radius of the initial area is adjusted synchronously until the correction radius is r' after a certain adjustment, and DJH∪D=D appears for the first time when the correction radius is r', where D represents the monitoring area, and the target area is determined according to the correction radius r'.

[0087] It is worth noting that when DJH∪D≠D, it means that the area composed of all target areas does not overlap with the monitoring area. Therefore, in order to make the area composed of all target areas cover the monitoring area, it is necessary to adjust the correction radius until the monitoring area can be completely covered to avoid missing photovoltaic power sources that do not belong to the monitoring area.

[0088] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A comprehensive control system for distributed photovoltaic power grid connection, characterized in that: include: Partitioning module: determine the monitoring area, obtain the location information of the transformer in the monitoring area, and plan the target area of ​​each transformer according to the location information of the transformer and the preset power threshold Pyz of the transformer; Power prediction module: set a monitoring period T, obtain the redundant power of the photovoltaic power source in real time during the monitoring period, and draw a curve f(t) of the redundant power changing with time, and use it as the target curve, and the redundant power is the difference between the generated power of the photovoltaic power source and the power consumed by the user; Calculating the average redundant power A straight line passing through (0, Ppj) and parallel to the x-axis is used as a reference line, and the intersection of the reference line and the target curve is used as a reference point. When the target curve between two adjacent reference points is above the reference line, it is used as an excess curve. When the target curve between two adjacent reference points is below the reference line, it is used as a shortage curve. Calculate the deviation coefficient K, and when the deviation coefficient K ≥ K', remove the deviation curve corresponding to the maximum deviation max (CJH), K' represents the preset deviation coefficient threshold, the deviation curve includes the excess curve and the shortage curve, CJH = (C1, C2, ..., C N1 , C1', C2', ..., C N2 '), where C N1 =max(g N1 (t))-Ppj,g N1 (t) represents the N1th excess curve, C N2 '=|min(h N2 (t))-Ppj|,h N2 (t) represents the N2th scarcity curve; Repeat the above steps and calculate the average redundant power and the deviation coefficient K until the deviation coefficient K is less than K' after removing the maximum deviation, and take the average redundant power at this time as the expected power PYQ of the photovoltaic power source; Control module: determining the target transformer of the photovoltaic power source in the target area according to the expected power, and the photovoltaic power source is connected to the grid through the target transformer when connected to the grid; In the power prediction module, the process of calculating the deviation coefficient K specifically includes: The deviation coefficient K is calculated by a formula, wherein the formula specifically includes: Where ε represents the preset correction coefficient, N = N1 + N2, and ti represents the time length corresponding to the i-th deviation curve; In the control module, the process of determining the target transformer of the photovoltaic power source in the target area according to the expected power specifically includes: Determine the target area A' corresponding to transformer A, and calculate the total expected power Ptot of the photovoltaic power source in the target area A'; When Ptot≤Pyz A When the photovoltaic power source in the target area A takes transformer A as the target transformer, Pyz A Indicates the power threshold of transformer A; When Ptot>Pyz A , perform the following steps: The photovoltaic power sources in the target area A' are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the first ranking is obtained; Starting from the first photovoltaic power source in the first ranking, m photovoltaic power sources are selected in sequence until m meets the following constraints: ∑m≥Pcz; ∑(m-1)<Pcz; Where Pcz = Ptot - Pyz A , ∑m represents the sum of the expected powers of the first m photovoltaic power sources, ∑(m-1) represents the sum of the expected powers of the first m-1 photovoltaic power sources, and transformer A is used as the target transformer for photovoltaic power sources whose sorting positions belong to [m+1, M], and M represents the total number of photovoltaic power sources in the target area A'; The process of determining the target transformer of the photovoltaic power source in the target area according to the expected power also includes: The photovoltaic power sources whose sorting positions in the first sorting corresponding to all target areas belong to [1, m] are taken as target power sources, and the target power sources are sorted according to the size of the deviation coefficient. The larger the deviation coefficient, the higher the ranking, and the second sorting is obtained; Determine the residual power PSY=Pcz-∑m of the transformer in the target area, and when the residual power PSY≥0, use the corresponding transformer as a pending transformer; Determine the undetermined transformer Y' that is closest to the target power source Y that is at the first place in the second sorting, and perform the following steps: When PYQ Y ≤PSY Y ', the undetermined transformer Y' is used as the target transformer of the target power source Y, PYQ Y Indicates the expected power of the target power source Y, PSY Y ' represents the remaining power of the pending transformer Y', and updates the remaining power of the pending transformer Y' PSY = PSY Y '-PYQ Y ; When PYQ Y >PSY Y ', remove the undetermined transformer Y' and determine the undetermined transformer closest to the target power source Y again, and repeat the above steps until the target transformer of the target power source Y is determined.

2. A comprehensive control system for distributed photovoltaic power grid connection according to claim 1, characterized in that: In the process of determining the first ranking, when there are two photovoltaic power sources with the same deviation coefficient, they are ranked according to the corresponding expected power. The larger the expected power, the lower the ranking.

3. The integrated control system for distributed photovoltaic power grid connection according to claim 1, characterized in that: The process of determining the pending transformer also includes the following steps: The minimum value PYQmin of the expected power of the target power source is obtained, and when the remaining power PSY<PYQmin, the corresponding transformer is no longer used as a pending transformer.

4. A distributed photovoltaic power grid-connected integrated control system according to claim 1, characterized in that: In the partitioning module, the process of planning the target area of ​​each transformer according to the location information of the transformer specifically includes: Obtain the location information of the transformer in the preset monitoring area, draw a circle with the location of the transformer as the center and the preset radius R to obtain the initial area; The number A of photovoltaic power sources in the initial area is obtained, and the transformer power threshold Pyz=a*Pys corresponding to the initial area is determined, where Pys represents the maximum power of the transformer and a is a first preset coefficient. The correction radius r=μ(a*Pys / A) is calculated, where μ represents a second preset coefficient. The initial area corresponding to the transformer is determined again according to the correction radius and is used as the target area.

5. A distributed photovoltaic power grid-connected integrated control system according to claim 4, characterized in that: The partitioning module further includes the following steps: Generate a target region set and DJH = (S1, S2, ..., Sn), Sn represents the nth target region, When DJH∪D≠D, the correction radius of the initial area is adjusted synchronously until the correction radius is r' after a certain adjustment, and DJH∪D=D appears for the first time when the correction radius is r', where D represents the monitoring area, and the target area is determined according to the correction radius r'.

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