A distributed photovoltaic receivable capacity quantitative analysis method and system

Abstract

The application discloses a kind of distributed photovoltaic receivable capacity quantitative analysis method and system, method includes: obtaining the basic parameters and operating data of distribution network, constructs topological parameter sequence and load data sequence;According to photovoltaic access node position, judge whether located main line or branch line;If located main line, based on full node voltage constraint calculation node voltage and back-propagation maximum receivable photovoltaic capacity;If located branch line, respectively calculate main line T junction and branch line access point before node voltage and back-propagation capacity;Capacity vector is obtained by traversing all nodes, take minimum value as first receivable capacity;Based on reverse overload constraint calculation transformer and line remaining capacity, combined with first receivable capacity to determine final distributed photovoltaic receivable capacity.The application realizes the accurate quantification of distribution network along the line full node photovoltaic receivable capacity, considers voltage out-of-limit and reverse overload double constraints simultaneously, provides scientific basis for distributed photovoltaic planning and dispatching.

Description

Technical Field

[0001] This invention belongs to the field of power distribution network operation and new energy grid connection technology, and in particular relates to a method and system for quantitative analysis of the acceptability of distributed photovoltaic power. Background Technology

[0002] The scale of distributed photovoltaic (PV) grid connection in distribution substations (especially urban and rural low-voltage distribution substations) continues to expand, becoming a core force in the transformation of renewable energy in these substations. Connection locations are mainly concentrated at various nodes within the substation (including user-side nodes and branch nodes), covering various types such as residential and small-scale industrial and commercial applications. However, distribution substations are characterized by dense nodes, high line impedance, significant load fluctuations, and limited transformer capacity. The node-based connection of distributed PV easily leads to two major problems: First, voltage exceeding limits. The intermittent and fluctuating nature of PV output causes the voltage amplitude at each node in the substation to deviate from the rated range (too high or too low), especially at the end nodes, where voltage exceeding limits is more prominent, seriously affecting the safe operation of electrical equipment. Second, reverse overload. When the total PV output in the substation exceeds the load demand, excess power is transmitted in reverse to the upstream grid, causing reverse overload phenomena in the substation transformers and main lines, accelerating equipment aging, and even triggering power supply failures in the substation.

[0003] Existing methods for assessing the acceptability of distributed photovoltaic (PV) systems have two major flaws for distribution substation scenarios, failing to meet the actual operational needs of these substations: First, the assessment accuracy is insufficient, as most methods only assess the acceptability of the entire distribution substation or a few key bus nodes, without being precise down to each individual node. This fails to reflect the differences in PV acceptance at different nodes, leading to voltage overruns and localized overloads at some nodes after PV integration, resulting in assessment results lacking engineering applicability. Second, core constraints are missing, failing to fully consider voltage overruns (including upper and lower voltage limits for each node) and reverse overloads (including transformer and line reverse overloads) in the distribution substation, thus failing to mitigate safety risks after PV integration in advance.

[0004] Meanwhile, existing assessment systems lack a quantitative model linking voltage constraints at all nodes along the transmission line with photovoltaic (PV) capacity, making it difficult to meet the practical engineering needs of distribution network planning, operation, and upgrades. Therefore, there is an urgent need for a quantitative assessment method and system for the distributed PV capacity at all nodes along a distribution network, enabling accurate quantification of PV capacity at each point along the transmission line, balancing assessment speed and accuracy, providing a scientific basis for distribution network PV grid connection planning and real-time dispatch, and contributing to the high-quality development of distributed PV. Summary of the Invention

[0005] This invention provides a method and system for quantitative analysis of the acceptability of distributed photovoltaic (PV) systems. It focuses on each node of a distribution transformer area, constructs a core constraint system including voltage over-limit and reverse overload, and combines node-level voltage calculation and fast solution algorithm to achieve accurate quantification of the PV acceptability capacity of each node in the transformer area. This solves the shortcomings of traditional methods that cannot be accurate to each node in the transformer area and do not consider voltage over-limit issues at the same time. It adapts to the needs of distributed PV node access in distribution transformer areas and ensures the safe and stable operation of the transformer area.

[0006] In a first aspect, the present invention provides a method for quantitative analysis of the acceptability of distributed photovoltaic power, comprising: Construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operational data of the distribution network; Based on the location of the photovoltaic access node in the distribution network, determine whether the photovoltaic access node is located on the main line or the branch line; If it is located on a branch line, the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line are calculated respectively, and the maximum photovoltaic capacity that the photovoltaic access point can accept is obtained by back-reasoning based on the full node voltage constraint condition. Traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector for each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. Based on the preset reverse overload constraint, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line are calculated, and the final acceptable capacity of distributed photovoltaic power in the distribution network is determined according to the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

[0007] Secondly, the present invention provides a distributed photovoltaic (PV) acceptance capacity quantitative analysis system, comprising: The module is configured to construct a sequence of distribution network topology parameters and a sequence of node load data based on the basic parameters and operational data of the distribution network. The judgment module is configured to determine whether the photovoltaic access node is located on the main line or the branch line based on its location in the distribution network. The calculation module is configured to calculate the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line if it is located on the branch line, and back-calculate the maximum acceptable photovoltaic capacity of the photovoltaic access node based on the full node voltage constraint condition. The module is configured to traverse all nodes in the distribution network, obtain the maximum acceptable photovoltaic capacity vector of each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. The output module is configured to calculate the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line based on a preset reverse overload constraint, and determine the final distributed photovoltaic acceptable capacity of the distribution network based on the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

[0008] Thirdly, an electronic device is provided, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the steps of the distributed photovoltaic acceptability quantification analysis method according to any embodiment of the present invention.

[0009] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the program instructions are executed by a processor, the processor performs the steps of the distributed photovoltaic acceptance capability quantification analysis method according to any embodiment of the present invention.

[0010] The method and system for quantitative analysis of the acceptability of distributed photovoltaic power in this application have the following beneficial effects: Taking each node along the distribution substation as the evaluation object, differentiated voltage calculation models are established for the main line node and the branch line node respectively. This can accurately quantify the distributed photovoltaic capacity that each node can accept, overcoming the shortcomings of traditional methods that only evaluate the entire substation or a few key nodes. The evaluation results are more practical for engineering. Simultaneously considering the full node voltage over-limit constraints (including upper and lower voltage limits) and reverse heavy overload constraints (including transformer reverse heavy overload and line reverse heavy overload), a complete constraint system is constructed, which can avoid the risks of voltage over-limit and heavy overload after photovoltaic access in advance and ensure the safe and stable operation of the distribution area. By introducing a neural network model and combining offline training with online deployment, a rapid assessment of the acceptability of distributed photovoltaic power was achieved. At the same time, the model accuracy was continuously optimized through an error feedback mechanism, thus balancing assessment speed and accuracy. Voltage calculation processes are designed separately for mainline nodes and branchline nodes. The voltage of each node between the transformer and the connection point is directly calculated for the mainline node, while the voltage of the branchline node is calculated first for the mainline T-junction and then for the branchline voltage. The logic is clear, the calculation is efficient, and it can adapt to complex distribution transformer area topologies. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 A flowchart illustrating a method for quantitative analysis of the acceptability of distributed photovoltaic power generation according to an embodiment of the present invention; Figure 2 A structural block diagram of a distributed photovoltaic acceptance capacity quantitative analysis system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Please see Figure 1 The flowchart illustrates a method for quantitative analysis of the acceptability of distributed photovoltaics according to this application.

[0015] like Figure 1 As shown, the quantitative analysis method for the acceptability of distributed photovoltaic power includes the following steps: Step S101: Construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operating data of the distribution network.

[0016] In this step, a typical 10kV distribution substation is used as an example. This substation includes one main line (numbered main line 01) and three branch lines (numbered branch line 01, branch line 02, and branch line 03, respectively). The main line has 15 nodes (node ​​numbers 1 to 15), branch line 01 has 8 nodes (node ​​numbers (1,1) to (1,8)), branch line 02 has 5 nodes, and branch line 03 has 6 nodes. The rated capacity of the substation transformer is S0 = 630kVA, and the rated voltage is U0 = 10kV.

[0017] First, through the Supervisory Control and Data Acquisition (SCADA) system for the power distribution network and smart measurement terminals (such as smart meters and feeder terminal units) deployed at each node, the following three types of data are collected simultaneously at the same time point (e.g., 12:00 noon on a certain day, during the peak photovoltaic output period): Basic parameters of the distribution network include the topological connection relationship of the transformer substations (parent-child relationship between nodes, T-junction position of main line and branch line), resistance R (unit Ω) and reactance X (unit Ω) of each line segment, rated capacity S0 of the transformer, rated voltage U0, and rated capacity S_line_max corresponding to the maximum allowable current carrying capacity of each line segment.

[0018] For example, the line resistance between node 1 and node 2 is R1=0.25Ω and the reactance is X1=0.35Ω; between node 2 and node 3, R2=0.20Ω and X2=0.30Ω; and so on.

[0019] Distribution network operation data includes the load active power P (kW), load reactive power Q (kvar), currently connected photovoltaic active power P_pv (kW) and photovoltaic reactive power Q_pv (kvar), real-time voltage amplitude U (kV) and voltage phase angle θ (degrees) of each node. This data is transmitted to the main station system via smart meters at a frequency of one point every 15 minutes.

[0020] Full node voltage monitoring data: used as verification data for subsequent verification of the accuracy of the voltage calculation model.

[0021] The collected topology parameters are sorted according to spatial geographic location or electrical connection order to form a unified serialized data structure, which facilitates subsequent sliding window calculations and node traversal.

[0022] Step S102: Determine whether the photovoltaic access node is located on the main line or the branch line based on its location in the distribution network.

[0023] In this step, after determining whether the photovoltaic access node is located on the main line or the branch line, if it is located on the main line, the voltage of each node on the main line is calculated based on the preset full node voltage constraint condition, the distribution network topology parameter sequence and the node load data sequence, and the maximum photovoltaic capacity that the photovoltaic access node can accept is obtained by reverse calculation.

[0024] It should be noted that when the photovoltaic access node is located on the main line, the voltage amplitude of each node between the transformer and the photovoltaic access node is calculated based on the rated voltage of the distribution network, the resistance and reactance of each line segment, the load power of each node, and the photovoltaic access capacity of the photovoltaic access node. For any node between the transformer and the photovoltaic access node, a voltage limit constraint is applied, that is, the voltage amplitude of any node is between a preset minimum voltage limit and a preset maximum voltage limit. Based on the aforementioned voltage limit constraint, the formula for calculating the maximum accessible photovoltaic active power at the photovoltaic access node is derived as follows: , , , In the formula, Let be the maximum photovoltaic active power that can be connected to node i. This represents the maximum voltage limit at node i. This represents the maximum voltage limit at node j. Let be the active power of node b. The resistance between node a-1 and node a. Let be the reactive power of node b. Let the reactance be between node a-1 and node a. This is the total number of nodes in the main storyline. The active power capacity of the distributed photovoltaic system connected to node (k,1) is... The distributed photovoltaic reactive power capacity connected to node (k,1); The maximum photovoltaic access capacity of the photovoltaic access node is calculated based on the maximum accessible photovoltaic active power and the preset ratio of reactive power to active power.

[0025] In one specific embodiment, the location of the photovoltaic node to be connected is first determined based on its number, indicating whether it is on the main line or a branch line. The node number is represented by a binary tuple (k, g), where k is the node's sequence number on the main line, and g is the branch line identifier: when g=1, the node is located on the main line; when g≠1, the node is located on a branch line (g is the branch line number). This section uses a main line node as an example to explain in detail the calculation process for its maximum accommodating photovoltaic capacity.

[0026] Suppose a distributed photovoltaic (PV) project is to be connected to the 5th node on the main line, i.e., node number (5,1). The system reads the distribution network topology parameter sequence and finds g=1, determining that the node is located on the main line. At this point, subsequent calculations only need to consider the main line section from the transformer outlet to this node; the node voltage after the connection point is not affected by the PV connection (because power is only fed back to the power source side).

[0027] According to the basic principles of power distribution network flow, node voltage gradually decreases from the transformer side to the end. When photovoltaic (PV) systems are connected, the PV output partially offsets the load demand, reducing the transmitted power on the lines and causing the voltage at each node to rise. The degree of voltage rise depends on the size of the PV capacity connected.

[0028] In specific implementation, the system extracts the following data from the power distribution network topology parameter sequence and load data sequence constructed in step S101: The total number of nodes in the main storyline, n (e.g., n=15); The rated voltage at the transformer outlet is 10kV; The resistances R1~R5 and reactances X1~X5 of each line segment between node 1 and node 5; Active power of each node (node ​​1 to node 15) and reactive power .

[0029] For the main line connection point (5,1), it is necessary to calculate the voltage at each node (i=1,2,3,4,5) between the transformer and this connection point. The basic idea for voltage calculation is to start from the transformer side and accumulate the voltage drop along the line segment by segment. The magnitude of the voltage drop depends on the difference between all loads downstream of that segment of the line and the photovoltaic output.

[0030] The system performs calculations according to the following recursive logic: Initialization: Set the voltage at node 0 (low-voltage side bus of transformer) to U0, and there is no load at node 0.

[0031] For node i (from 1 to 5): Calculate the sum of the total active power of the load from node i to the end of the main line (node ​​n), and the sum of the total reactive power of the load.

[0032] The active power capacity of the photovoltaic access point (5,1) is P pv,5 (Unknown, to be determined), reactive power capacity Q pv,5 =0.05× P pv,5 .

[0033] When i≤5, this node is located before the photovoltaic access point, and the active power flowing through it is: reactive power is .

[0034] The voltage drop across this section of the line (between node i-1 and node i) is approximately: .

[0035] Voltage of node i =Voltage at node i-1 -Δ U i .

[0036] Through the above recursion, the voltages of nodes 1 to 5 can be expressed as unknowns. The linear expression of .

[0037] To ensure the safe operation of the distribution network, the voltage of each node i (i=1,…,5) must meet the allowable range specified by national standards or internal company regulations. In this embodiment, for a 10kV distribution network, a lower voltage limit is set. U min =9.3kV, upper voltage limit U max =10.7kV.

[0038] In actual operation, voltage exceeding the limit usually occurs at the highest voltage point (near the transformer side, where the voltage may be excessively high due to photovoltaic backfeed) or the lowest voltage point (at the end, where the voltage may drop excessively low due to undervoltage). In photovoltaic grid connection scenarios, the main threat is voltage exceeding the upper limit. Therefore, the system focuses on checking whether the voltage at each node exceeds 10.7 kV.

[0039] Based on the voltage expression and constraints, the system solves for the condition that the voltage at any node exactly reaches the upper limit value. Since the voltage expression is linear, the maximum connectable capacity corresponds to the most stringent node constraints.

[0040] Step S103: If it is located on a branch line, calculate the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line, and back-calculate the maximum acceptable photovoltaic capacity of the photovoltaic access node based on the full node voltage constraint condition.

[0041] In this step, when the photovoltaic access node is located on the branch line, the voltage of each node on the main line between the transformer and the branch line T-junction is calculated, and a voltage limit constraint is applied to obtain the maximum distributed photovoltaic backfeed power of the branch line T-junction. Calculate the voltage at each node of the branch line between the branch line T-junction and the photovoltaic access point, apply the voltage limit constraint, and derive the maximum photovoltaic active power that the photovoltaic access point can transmit back. Based on the maximum reversible photovoltaic active power and the preset ratio of reactive power to active power, the maximum photovoltaic access capacity of the photovoltaic access node is calculated.

[0042] It should be noted that the expression for calculating the maximum photovoltaic active power that can be fed back from the photovoltaic access point is as follows: , , , In the formula, Let (s,k) be the maximum photovoltaic active power that can be connected. This represents the maximum voltage limit at node j. Let j be the voltage amplitude at node j on the branch line. Let be the active power of node b. The resistance between node a-1 and node a. Let be the reactive power of node b. Let the reactance be between node a-1 and node a. This is the total number of nodes in the main storyline. This represents the total number of branch nodes. Let (s,k) be the maximum photovoltaic active power that can be connected. Let (s,k) be the maximum photovoltaic active power that can be connected to the node.

[0043] Step S104: Traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector of each node, and determine the first acceptable capacity based on the minimum value of the maximum acceptable photovoltaic capacity vector of each node.

[0044] Step S105: Based on the preset reverse overload constraint, calculate the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line, and determine the final distributed photovoltaic acceptable capacity of the distribution network according to the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

[0045] In this step, with the constraint of not causing reverse overload of the transformer, the remaining photovoltaic capacity that can be connected to the transformer is calculated based on the rated capacity of the transformer and the minimum daytime load on the transformer side. With the constraint of not causing reverse overload on the line, the minimum acceptable photovoltaic capacity of each line segment between the photovoltaic access point and the terminal node is calculated, and the minimum value of the minimum acceptable photovoltaic capacity of each line segment is taken as the minimum acceptable capacity of the line.

[0046] It should be noted that the formula for calculating the remaining photovoltaic capacity that can be connected to the transformer is as follows: , In the formula, This refers to the remaining photovoltaic capacity that can be connected to the transformer. The rated capacity of the transformer. This represents the transformer's minimum active power during the day. This represents the transformer's minimum reactive power during the day. The formula for calculating the minimum acceptable capacity of the line is: , , In the formula, This represents the minimum acceptable photovoltaic capacity for the line segment preceding the photovoltaic grid connection point. Let k be the acceptable photovoltaic capacity of the photovoltaic grid connection point. Let be the minimum active power during the day from node k to the terminal node n. Let be the minimum reactive power during the day from node k to the terminal node n. This refers to the line's capacity.

[0047] In summary, the method of this application obtains the basic parameters and operational data of the distribution network, constructs a topology parameter sequence and a load data sequence; determines whether the photovoltaic access node is located on the main line or a branch line based on its location; if located on the main line, calculates the node voltage based on the voltage constraints of all nodes and inversely infers the maximum acceptable photovoltaic capacity; if located on a branch line, calculates the node voltage before the T-junction of the main line and before the access point of the branch line respectively and inversely infers the capacity; traverses all nodes to obtain the capacity vector, and takes the minimum value as the first acceptable capacity; calculates the remaining capacity of the transformer and line based on the reverse heavy overload constraint, and determines the final acceptable capacity of distributed photovoltaics in combination with the first acceptable capacity; achieves accurate quantification of the acceptable capacity of photovoltaics at all nodes along the distribution network, while considering the dual constraints of voltage over-limit and reverse heavy overload, providing a scientific basis for distributed photovoltaic planning and scheduling.

[0048] Please see Figure 2 The diagram shows a structural block diagram of a distributed photovoltaic acceptability quantitative analysis system according to this application.

[0049] like Figure 2 As shown, the distributed photovoltaic acceptance capacity quantitative analysis system 200 includes a construction module 210, a judgment module 220, a calculation module 230, a determination module 240, and an output module 250.

[0050] The system comprises the following modules: a construction module 210, configured to construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operational data of the distribution network; a judgment module 220, configured to determine whether the photovoltaic access node is located on the main line or a branch line based on its position in the distribution network; a calculation module 230, configured to calculate the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line if the node is located on a branch line, and to back-calculate the maximum acceptable photovoltaic capacity of the photovoltaic access node based on the full node voltage constraint condition; a determination module 240, configured to traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector of each node, and to determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node; and an output module 250, configured to calculate the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line based on a preset reverse overload constraint condition, and to determine the final distributed photovoltaic acceptable capacity of the distribution network based on the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer, and the minimum acceptable capacity of the line.

[0051] It should be understood that Figure 2 The modules and references described in the document Figure 1 The steps described in the text correspond to those in the method described above. Therefore, the operations, features, and corresponding technical effects described above also apply to the method described in the text. Figure 2 The various modules in the document will not be described in detail here.

[0052] In other embodiments, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the program instructions are executed by a processor, the processor performs the distributed photovoltaic acceptance capability quantification analysis method in any of the above method embodiments. In one embodiment, the computer-readable storage medium of the present invention stores computer-executable instructions, which are configured as follows: Construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operational data of the distribution network; Based on the location of the photovoltaic access node in the distribution network, determine whether the photovoltaic access node is located on the main line or the branch line; If it is located on a branch line, the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line are calculated respectively, and the maximum photovoltaic capacity that the photovoltaic access point can accept is obtained by back-reasoning based on the full node voltage constraint condition. Traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector for each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. Based on the preset reverse overload constraint, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line are calculated, and the final acceptable capacity of distributed photovoltaic power in the distribution network is determined according to the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

[0053] Computer-readable storage media may include a stored program area and a stored data area, wherein the stored program area may store an operating system and an application program required for at least one function; the stored data area may store data created based on the use of the distributed photovoltaic acceptability quantification analysis system, etc. Furthermore, the computer-readable storage medium may include high-speed random access memory, and may also include memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the computer-readable storage medium may optionally include memory remotely located relative to a processor, which can be connected to the distributed photovoltaic acceptability quantification analysis system via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0054] Figure 3 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention, such as... Figure 3 As shown, the device includes a processor 310 and a memory 320. The electronic device may also include an input device 330 and an output device 340. The processor 310, memory 320, input device 330, and output device 340 can be connected via a bus or other means. Figure 3 Taking a bus connection as an example, the memory 320 is the computer-readable storage medium described above. The processor 310 executes various server functions and data processing by running non-volatile software programs, instructions, and modules stored in the memory 320, thereby implementing the distributed photovoltaic (PV) acceptability quantification analysis method described in the above embodiment. The input device 330 can receive input digital or character information and generate key signal inputs related to user settings and function control of the distributed PV acceptability quantification analysis system. The output device 340 may include a display screen or other display device.

[0055] The aforementioned electronic device can execute the method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the method provided in the embodiments of the present invention.

[0056] In one implementation, the above-described electronic device is used in a distributed photovoltaic (PV) acceptance capacity quantification analysis system for a client, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to: Construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operational data of the distribution network; Based on the location of the photovoltaic access node in the distribution network, determine whether the photovoltaic access node is located on the main line or the branch line; If it is located on a branch line, the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line are calculated respectively, and the maximum photovoltaic capacity that the photovoltaic access point can accept is obtained by back-reasoning based on the full node voltage constraint condition. Traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector for each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. Based on the preset reverse overload constraint, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line are calculated, and the final acceptable capacity of distributed photovoltaic power in the distribution network is determined according to the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

[0057] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for quantitatively analyzing the acceptability of distributed photovoltaic power, characterized in that, include: Construct a distribution network topology parameter sequence and a node load data sequence based on the basic parameters and operational data of the distribution network; Based on the location of the photovoltaic access node in the distribution network, determine whether the photovoltaic access node is located on the main line or the branch line; If it is located on a branch line, the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line are calculated respectively, and the maximum photovoltaic capacity that the photovoltaic access point can accept is obtained by back-reasoning based on the full node voltage constraint condition. Traverse all nodes in the distribution network to obtain the maximum acceptable photovoltaic capacity vector for each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. Based on the preset reverse overload constraint, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line are calculated, and the final acceptable capacity of distributed photovoltaic power in the distribution network is determined according to the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

2. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 1, characterized in that, After determining whether the photovoltaic access node is located on the main line or a branch line, the method further includes: If located on the main line, the voltage of each node on the main line is calculated based on the preset full node voltage constraint conditions, according to the distribution network topology parameter sequence and the node load data sequence, and the maximum acceptable photovoltaic capacity of the photovoltaic access node is obtained by reverse calculation.

3. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 2, characterized in that, The method, based on preset full-node voltage constraints, calculates the voltage of each node on the main line according to the distribution network topology parameter sequence and the node load data sequence, and then reverse-engineers the maximum accommodative photovoltaic capacity of the photovoltaic access node, including: When the photovoltaic access node is located on the main line, the voltage amplitude of each node between the transformer and the photovoltaic access node is calculated based on the rated voltage of the distribution network, the resistance and reactance of each line segment, the load power of each node, and the photovoltaic access capacity of the photovoltaic access node. For any node between the transformer and the photovoltaic access node, a voltage limit constraint is applied, that is, the voltage amplitude of any node is between a preset minimum voltage limit and a preset maximum voltage limit. Based on the aforementioned voltage limit constraint, the formula for calculating the maximum accessible photovoltaic active power of the photovoltaic access node is derived as follows: ， ， In the formula, Let be the maximum photovoltaic active power that can be connected to node i. This represents the maximum voltage limit for node i. This represents the maximum voltage limit at node j. Let be the active power of node b. Let the resistance be between node a-1 and node a. Let be the reactive power of node b. Let the reactance be between node a-1 and node a. This is the total number of nodes in the main storyline. The active power capacity of the distributed photovoltaic system connected to node (k,1) is... The distributed photovoltaic reactive power capacity connected to node (k,1); The maximum photovoltaic access capacity of the photovoltaic access node is calculated based on the maximum accessible photovoltaic active power and the preset ratio of reactive power to active power.

4. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 1, characterized in that, If located on a branch line, the voltage of each node before the T-junction on the main line and the voltage of each node before the photovoltaic access point on the branch line are calculated respectively. Based on the total node voltage constraint, the maximum acceptable photovoltaic capacity of the photovoltaic access node is derived by back-calculation, including: When the photovoltaic access node is located on a branch line, calculate the voltage of each node on the main line between the transformer and the branch line T-junction, apply the voltage limit constraint, and obtain the maximum distributed photovoltaic backfeed power of the branch line T-junction. Calculate the voltage at each node of the branch line between the branch line T-junction and the photovoltaic access point, apply the voltage limit constraint, and derive the maximum photovoltaic active power that the photovoltaic access point can transmit back. Based on the maximum reversible photovoltaic active power and the preset ratio of reactive power to active power, the maximum photovoltaic access capacity of the photovoltaic access node is calculated.

5. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 4, characterized in that, The expression for calculating the maximum photovoltaic active power that can be fed back from the photovoltaic access point is: ， ， In the formula, Let (s,k) be the maximum photovoltaic active power that can be connected. This represents the maximum voltage limit at node j. Let j be the voltage amplitude at node j on the branch line. Let be the active power of node b. Let the resistance be between node a-1 and node a. Let be the reactive power of node b. Let the reactance be between node a-1 and node a. This is the total number of nodes in the main storyline. This represents the total number of branch nodes. Let (s,k) be the maximum photovoltaic active power that can be connected. Let (s,k) be the maximum photovoltaic active power that can be connected to the node.

6. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 1, characterized in that, The calculation of the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line based on the preset reverse overload constraint conditions includes: With the constraint of not causing reverse overload of the transformer, the remaining photovoltaic capacity that can be connected to the transformer is calculated based on the rated capacity of the transformer and the minimum daytime load on the transformer side. With the constraint of not causing reverse overload on the line, the minimum acceptable photovoltaic capacity of each line segment between the photovoltaic access point and the terminal node is calculated, and the minimum value of the minimum acceptable photovoltaic capacity of each line segment is taken as the minimum acceptable capacity of the line.

7. The method for quantitative analysis of the acceptability of distributed photovoltaic power according to claim 1, characterized in that, The formula for calculating the remaining photovoltaic capacity that can be connected to the transformer is: ， In the formula, This refers to the remaining photovoltaic capacity that can be connected to the transformer. The rated capacity of the transformer. This represents the transformer's minimum active power during the day. This represents the transformer's minimum reactive power during the day. The formula for calculating the minimum acceptable capacity of the line is: ， ， In the formula, This represents the minimum acceptable photovoltaic capacity for the line segment preceding the photovoltaic grid connection point. Let k be the acceptable photovoltaic capacity of the photovoltaic grid connection point. Let be the minimum active power during the day from node k to the terminal node n. Let be the minimum reactive power during the day from node k to the terminal node n. This refers to the line's capacity.

8. A quantitative analysis system for the acceptability of distributed photovoltaic power, characterized in that, include: The module is configured to construct a sequence of distribution network topology parameters and a sequence of node load data based on the basic parameters and operational data of the distribution network. The judgment module is configured to determine whether the photovoltaic access node is located on the main line or the branch line based on its location in the distribution network. The calculation module is configured to calculate the voltage of each node before the T-junction of the main line and the voltage of each node before the photovoltaic access point of the branch line if it is located on the branch line, and back-calculate the maximum acceptable photovoltaic capacity of the photovoltaic access node based on the full node voltage constraint condition. The module is configured to traverse all nodes in the distribution network, obtain the maximum acceptable photovoltaic capacity vector of each node, and determine the first acceptable capacity based on the minimum value among the maximum acceptable photovoltaic capacity vectors of each node. The output module is configured to calculate the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line based on a preset reverse overload constraint, and determine the final distributed photovoltaic acceptable capacity of the distribution network based on the minimum value among the first acceptable capacity, the remaining acceptable capacity of the transformer and the minimum acceptable capacity of the line.

9. An electronic device, characterized in that, include: At least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method according to any one of claims 1 to 7.

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