AC power flow calculation method and system for distribution network based on power generation load transfer factor

Abstract

The present invention belongs to the technical field of power distribution network flow analysis of electric power system, and provides a distribution network AC flow calculation method and system based on power generation load transfer factor. The method includes: determining the topological structure of the distribution network system, combining the apparent power of the branch, the voltage amplitude and phase angle at the node, and obtaining a linear AC flow model; selecting a reference point, determining the reference voltage amplitude and the reference voltage phase angle; according to Kirchhoff's law, the node net power is expressed by the flow of the branch connected to it, and combined with the linear AC flow model, the node net power calculation formula is obtained; the node net power calculation formula is converted into a matrix form, and according to the matrix form of the node net power calculation formula, the reference voltage amplitude and the reference voltage phase angle are combined to obtain the calculation formula of the voltage amplitude and the phase angle; according to the calculation formula of the voltage amplitude and the phase angle, the linear AC flow model and the power generation load transfer factor calculation formula, the calculation formula of the branch flow is determined to obtain the branch flow.

Description

Technical Field

[0001] The invention belongs to the technical field of power flow analysis of distribution networks in power systems, and particularly relates to a method and system for calculating AC power flow of a distribution network based on generation load transfer factors. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] Renewable energy has volatility and randomness. With the increasing penetration of renewable energy in distribution networks, it has brought huge negative impacts on the safe operation of distribution networks. In this context, rapid power flow analysis is more significant for the operation and control of distribution networks.

[0004] Different from classical algorithms such as the Gauss - Seidel algorithm, Newton - Raphson algorithm, and fast decoupled method, in order to quickly solve the power flow, some methods that do not require iteration have been proposed, such as using generation load transfer factors to solve branch power flow. This method only depends on the topological structure and parameters of the system. Once the topological structure and parameters of the system are determined, the generation load transfer factors can be obtained. Based on the known generation load transfer factors and the net power at nodes, the branch power flow can be quickly calculated. However, this method is based on DC power flow. In distribution networks, the assumption of R << X no longer holds, and traditional generation load transfer factors based on DC power flow are not applicable to distribution networks, and reactive power flow and voltage need to be considered. Summary of the Invention

[0005] In order to solve the technical problem of how to accurately and quickly solve the active power flow, reactive power flow, and voltage of a distribution network and combine them with the optimal operation and safety analysis of the distribution network, the present invention provides a method and system for calculating AC power flow of a distribution network based on generation load transfer factors, which can quickly solve the active power flow, reactive power flow, voltage amplitude, and phase angle of the distribution network.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides a method for calculating AC power flow of a distribution network based on generation load transfer factors.

[0008] The method for calculating AC power flow of a distribution network based on generation load transfer factors includes:

[0009] Determine the topological structure of the distribution network system, and combine the apparent power of the branch, the voltage amplitude and phase angle at the node to obtain a linear AC power flow model;

[0010] Select a reference point and determine the reference voltage amplitude and reference voltage phase angle;

[0011] According to Kirchhoff's law, the node net power is expressed by the power flow of the branch connected to it, and combined with the linear AC power flow model, the node net power calculation formula is obtained;

[0012] The node net power calculation formula is converted into a matrix form, and according to the matrix form of the node net power calculation formula, the voltage amplitude calculation formula and the phase angle calculation formula are obtained by combining the reference voltage amplitude and the reference voltage phase angle;

[0013] According to the calculation formula of voltage amplitude, phase angle, linear AC power flow model and power generation load transfer factor, the calculation formula of branch power flow is obtained;

[0014] The branch flow is obtained according to the calculation formula of branch flow.

[0015] Furthermore, the calculation formula of the branch power flow includes a calculation formula of the branch active power flow and a calculation formula of the branch reactive power flow.

[0016] Furthermore, according to the calculation formula of the branch active power flow and the calculation formula of the branch reactive power flow, the branch power flow constraint is constructed.

[0017] Furthermore, according to the linearization processing method, the branch power flow constraints are processed and converted into linear constraints.

[0018] Furthermore, after obtaining the calculation formula for the voltage amplitude and the calculation formula for the phase angle, the method further includes obtaining upper and lower limit constraints of the voltage amplitude and upper and lower limit constraints of the phase angle according to the calculation formula for the voltage amplitude and the calculation formula for the phase angle.

[0019] Furthermore, after determining the topological structure of the distribution network system, it also includes modeling the topological structure of the distribution network system and converting graphic information into data information.

[0020] Furthermore, the AC power flow assumes that the three-phase distribution network is balanced, cosθ ij ≈1, sinθ ij ≈θi j ;

[0021] Furthermore, in the node net power calculation formula, the node net power is represented only by the node voltage amplitude and phase angle and line parameters;

[0022] Furthermore, the mapping relationship matrix between node net power and node voltage amplitude and phase angle is singular. In order to solve its inverse matrix, the two rows and two columns where the reference node is located need to be deleted;

[0023] Furthermore, the calculation formula for the voltage amplitude and the calculation formula for the phase angle are both represented by only the line parameters and the node net power;

[0024] Furthermore, the branch power flow calculation formula is represented only by the generation load transfer factor and the node net power;

[0025] Furthermore, the generation load transfer factor depends only on the distribution network system topology and line parameters.

[0026] A second aspect of the present invention provides a distribution network AC power flow calculation system based on power generation load transfer factors.

[0027] The distribution network AC power flow calculation system based on power generation load transfer factor includes:

[0028] A model building module is configured to: determine the topology of the distribution network system, and obtain a linear AC power flow model by combining the apparent power of the branch, the voltage amplitude and the phase angle at the node;

[0029] A reference selection module is configured to: select a reference point, determine a reference voltage amplitude and a reference voltage phase angle;

[0030] The first calculation module is configured to: express the node net power by the power flow of the branch connected to it according to Kirchhoff's law, and combine it with the linear AC power flow model to obtain the node net power calculation formula;

[0031] A second calculation module is configured to: convert the node net power calculation formula into a matrix form, and obtain a voltage amplitude calculation formula and a phase angle calculation formula according to the matrix form of the node net power calculation formula, combined with a reference voltage amplitude and a reference voltage phase angle;

[0032] A third calculation module is configured to obtain a calculation formula for branch power flow according to a calculation formula for voltage amplitude, a calculation formula for phase angle, a linear AC power flow model, and a calculation formula for power generation load transfer factor;

[0033] The power flow output module is configured to obtain the branch power flow according to the calculation formula of the branch power flow.

[0034] A third aspect of the present invention provides a computer-readable storage medium.

[0035] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps in the distribution network AC power flow calculation method based on the power generation load transfer factor as described in the first aspect above.

[0036] A fourth aspect of the present invention provides a computer device.

[0037] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in the method for calculating AC power flow in a distribution network based on a power generation load transfer factor as described in the first aspect above are implemented.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention takes into account the actual characteristics of the distribution network, and takes into account the voltage amplitude, phase angle and reactive power of the distribution network in the process of deriving the power generation load transfer factor, and is suitable for power flow optimization, safety analysis and voltage control.

[0040] The invention is different from the existing power generation load transfer factor based on DC power flow, and the proposed power generation load transfer factor is particularly suitable for distribution networks.

[0041] The power generation load transfer factor proposed in the present invention does not require iteration and can be used to quickly solve the active power flow and reactive power flow of the distribution network, and has the same accuracy as the linear AC power flow model.

[0042] The present invention proposes a calculation formula for branch active power flow, branch reactive power flow and voltage amplitude based on node net power, line parameters and power generation load transfer factor, and then constrains the upper and lower limits thereof, which can be conveniently embedded in the distribution network optimization operation model without increasing the complexity of the model.

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0045] Figure 1 is a flow chart of a method for calculating AC power flow in a distribution network based on a power generation load transfer factor according to a first embodiment of the present invention;

[0046] Figure 2 is a framework diagram of a distribution network AC power flow calculation system based on power generation load transfer factor shown in the second embodiment of the present invention;

[0047] Figure 3 is a schematic diagram of a distribution network branch shown in Embodiment 1 of the present invention;

[0048] Figure 4 This is a flow chart of derivation of power generation load transfer factor shown in the first embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0050] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the methods and systems according to various embodiments of the present disclosure. It should be noted that each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the module, program segment, or a part of a code may include one or more executable instructions for implementing the logical functions specified in each embodiment. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the flowchart and / or block diagram, and the combination of boxes in the flowchart and / or block diagram can be implemented using a dedicated hardware-based system that performs a specified function or operation, or can be implemented using a combination of dedicated hardware and computer instructions.

[0053] Embodiment 1

[0054] like Figure 1As shown, this embodiment provides a method for calculating the AC power flow of a distribution network based on a power generation load transfer factor. This embodiment uses the method applied to a server as an example. It can be understood that the method can also be applied to a terminal, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. The server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network servers, cloud communications, middleware services, domain name services, security services CDN, and big data and artificial intelligence platforms. The terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, etc., but is not limited to this. The terminal and the server can be directly or indirectly connected via wired or wireless communication, which is not limited in this application. In this embodiment, the method includes the following steps:

[0055] S101: Deriving Linear AC Power Flow Models

[0056] In step S101, the derivation of the linear AC power flow model is divided into three steps.

[0057] The following explanations are required for the distribution network system mentioned: the linear AC power flow model does not require the distribution network to be radial, and assumes that the distribution network is three-phase balanced.

[0058] Specifically, the three steps of deriving the linear AC power flow model are as follows.

[0059] The first step, such as Figure 3 The apparent power of the branch shown satisfies the following formula:

[0060]

[0061] Where Sij represents the apparent power of line ij; Represents the voltage phasor at node i; V i 2 Represents the square of the voltage amplitude on the node; represents the conjugate of the current phasor; g ij 、b ij They represent the conductance and susceptance on branch ij respectively.

[0062] In the second step, substitute equation (2) into equation (1) to obtain equation (3), and then obtain the precise expression of active power flow and reactive power flow (4).

[0063]

[0064]

[0065]

[0066] Where P ij ,Q ij Respectively represent the net active power and net reactive power on branch ij; θ i represents the voltage phase angle at node i; θ ij represents the difference in voltage phase angle between nodes i and j; represent the imaginary and real parts of the phasor respectively.

[0067] The third step, based on the second step, assume that cosθ ij ≈1, sinθ ij ≈θ ij , formula (4) is simplified as follows: V i (V i –V j )≈V i –V j , V i V j ≈1. Then the precise AC branch power flow is transformed into a linear AC power flow, as shown in the following formula:

[0068]

[0069] It should be noted that formula (5) is applicable to the cases where the R / X value is large or small.

[0070] S102: Based on the linear AC power flow model, a new model of generation load transfer factor applicable to the distribution network is derived. The derivation process is as follows: Figure 4 shown.

[0071] In step S102, the derivation of the new model of power generation load transfer factor is divided into eight steps.

[0072] Specifically, the eight steps of deriving the new model of power generation load transfer factor are as follows.

[0073] The first step is to select a reference node whose voltage amplitude is V ref , the voltage phase angle is θ ref .

[0074] In the second step, according to Kirchhoff's law, the net power of a node is equal to the algebraic sum of the branch flows with it as the endpoint, so the net power of the node is as follows:

[0075]

[0076] The third step is to substitute equation (5) into equation (6) to obtain the node net power calculation formula represented by the node voltage amplitude and phase angle and line parameters, as shown in the following equation:

[0077]

[0078] In the formula,

[0079]

[0080]

[0081] The fourth step is to transform equation (7) into a matrix form, as shown below:

[0082]

[0083] Where NI is the set of nodes; P, Q, V, G, The elements of P, Q, V, and θ are P i ,Q i ,V i ,θ i The elements of G and B are G ij , B ij .

[0084] Step 5: Delete the two rows and two columns where the reference node is located in equation (10), and get equations (11)-(12). It should be noted that the X matrix before deletion is singular, and the X matrix X' after deletion is non-singular, and there is an inverse matrix.

[0085]

[0086]

[0087] In the formula, G ref , P',Q',V', G', G ref , B ref The element is G i(ref) , B i(ref) .

[0088] The sixth step is to obtain the matrix form (13) of the general calculation formula for voltage amplitude and phase angle according to formula (11). It should be noted that in formula (13), only the node net power and line parameters need to be known to calculate the voltage amplitude and phase angle of each node.

[0089]

[0090] In the formula, the element of the M matrix is ​​m ij ; The element of N is n ij ;

[0091] Step 7: Expand (13) to obtain the general calculation formulas (14)-(15) for the voltage amplitude and phase angle of each node, where (15) is the parameter in (14). Calculation formula.

[0092]

[0093]

[0094] Step 8: Substitute equation (14) into equation (5) to obtain:

[0095]

[0096] Rearrange formula (16) and convert P k , Q k The coefficients of are combined to obtain the general calculation formula (17) for branch power flow, where P k , Q k The coefficients are active and reactive power generation load transfer factors The calculation formula of the generation load transfer factor and the related parameters in the branch power flow calculation formula As shown in (18). It should be noted that in the general calculation formula of the branch power flow, only the generation load transfer factor and the node power need to be known to calculate the branch power flow.

[0097]

[0098]

[0099] In the formula, NL = {NL none ,NL end ,NL start}.NL none Indicates the set of branches that do not end at the reference node; NL start Represents the branch set with the reference node as the head node; NL end represents the set of branches with the reference node as the terminal node; denote the active and reactive generation load transfer factors respectively; are the relevant parameters in the branch power flow calculation formula.

[0100] According to equations (14) and (17), the branch power flow constraints, voltage amplitude and phase angle upper and lower limit constraints are obtained as shown in the following equations:

[0101]

[0102]

[0103]

[0104] In the formula, represents the maximum capacity of branch ij; They represent the upper and lower limits of the voltage amplitude at node i respectively; loc(g)=k means that unit g is located at node k.

[0105] S103: According to the linearization processing method, the nonlinear part (19) in the model is processed and converted into a linear model.

[0106]

[0107] In the formula,

[0108] This embodiment constructs a new model of power generation load transfer factor based on linear AC power flow applicable to distribution network, rigorously derives the calculation of active and reactive power generation load transfer factors, and rigorously analyzes and expresses active and reactive branch power flow, node voltage amplitude and phase angle. In addition, the nonlinear branch power flow constraint is converted into a linear constraint, which improves the efficiency and reliability of problem solving.

[0109] The new model of power generation load transfer factor based on linear AC power flow constructed in this embodiment, the power generation load transfer factor only depends on the system topology and line parameters, the model is linear and does not require iteration, has the same accuracy as the linear AC power flow, and can be directly applied to the fast calculation, safety analysis, voltage control and other aspects of distribution network power flow, as well as the distribution network optimization operation model.

[0110] Embodiment 2

[0111] This embodiment provides a distribution network AC power flow calculation system based on power generation load transfer factor.

[0112] like Figure 2 As shown, the distribution network AC power flow calculation system based on the power generation load transfer factor includes:

[0113] A model building module is configured to: determine the topology of the distribution network system, and obtain a linear AC power flow model by combining the apparent power of the branch, the voltage amplitude and the phase angle at the node;

[0114] A reference selection module is configured to: select a reference point, determine a reference voltage amplitude and a reference voltage phase angle;

[0115] The first calculation module is configured to: express the node net power by the power flow of the branch connected to it according to Kirchhoff's law, and combine it with the linear AC power flow model to obtain the node net power calculation formula;

[0116] A second calculation module is configured to: convert the node net power calculation formula into a matrix form, and obtain a voltage amplitude calculation formula and a phase angle calculation formula according to the matrix form of the node net power calculation formula, combined with a reference voltage amplitude and a reference voltage phase angle;

[0117] A third calculation module is configured to obtain a calculation formula for branch power flow according to a calculation formula for voltage amplitude, a calculation formula for phase angle, a linear AC power flow model, and a calculation formula for power generation load transfer factor;

[0118] The power flow output module is configured to obtain the branch power flow according to the calculation formula of the branch power flow.

[0119] As one or more implementation modes, it also includes a first constraint module, which is configured to: construct a branch flow constraint according to a calculation formula of the branch active power flow and a calculation formula of the branch reactive power flow.

[0120] As one or more implementation modes, it also includes a linear processing module, which is configured to: process the branch power flow constraints according to a linearization processing method and convert them into linear constraints.

[0121] As one or more implementation modes, a second constraint module is further included, which is configured to: obtain upper and lower limit constraints of the voltage amplitude and upper and lower limit constraints of the phase angle according to the calculation formula of the voltage amplitude and the calculation formula of the phase angle.

[0122] It should be noted that the above-mentioned model building module, reference selection module, first calculation module, second calculation module, third calculation module, power flow output module, first constraint module, linear processing module and second constraint module are the same as the examples and application scenarios implemented by the steps in Embodiment 1, but are not limited to the contents disclosed in Embodiment 1. It should be noted that the above-mentioned modules as part of the system can be executed in a computer system such as a set of computer executable instructions.

[0123] Embodiment 3

[0124] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the method for calculating AC power flow in a distribution network based on a power generation load transfer factor as described in the first embodiment above are implemented.

[0125] Embodiment 4

[0126] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for calculating AC power flow in a distribution network based on a power generation load transfer factor as described in the first embodiment above are implemented.

[0127] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0128] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0129] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0130] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0131] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calculating AC power flow in a distribution network based on power generation load transfer factors, characterized in that: include: Determine the topology of the distribution network system, and obtain the linear AC power flow model by combining the apparent power of the branch, the voltage amplitude and phase angle at the node; Select a reference point, determine the reference voltage amplitude and reference voltage phase angle; According to Kirchhoff's law, the node net power is expressed by the power flow of the branch connected to it, and combined with the linear AC power flow model, the node net power calculation formula is obtained; The node net power calculation formula is converted into a matrix form, and according to the matrix form of the node net power calculation formula, the voltage amplitude calculation formula and the phase angle calculation formula are obtained by combining the reference voltage amplitude and the reference voltage phase angle; According to the calculation formula of voltage amplitude, phase angle, linear AC power flow model and power generation load transfer factor, the calculation formula of branch power flow is obtained; According to the calculation formula of branch power flow, the branch power flow is obtained; The calculation formula of the voltage amplitude is expressed by the following formula: The calculation formula of the phase angle is expressed by the following formula: Among them, θ i represents the voltage phase angle at node i; V ref represents the voltage amplitude of the reference node, θ ref represents the voltage phase angle of the reference node; The calculation formula of the power generation load transfer factor is expressed by the following formula: in, Respectively represent the active and reactive power generation load transfer factors; g ij , b ij Respectively represent the conductance and susceptance on branch ij; The calculation formula of the branch flow is expressed by the following formula: in, is the relevant parameter in the branch power flow calculation formula, NL={NL none ,NL end ,NL start };NL none Indicates the set of branches that do not end at the reference node; NL start Represents the branch set with the reference node as the head node; NL end Represents the set of branches with the reference node as the terminal node.

2. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: The calculation formula of the branch power flow includes the calculation formula of the branch active power flow and the calculation formula of the branch reactive power flow.

3. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 2, characterized in that: According to the calculation formula of branch active power flow and branch reactive power flow, the branch power flow constraint is constructed.

4. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 3, characterized in that: According to the linearization method, the branch power flow constraints are processed and converted into linear constraints.

5. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: After obtaining the calculation formula for the voltage amplitude and the calculation formula for the phase angle, the method further includes obtaining upper and lower limit constraints of the voltage amplitude and upper and lower limit constraints of the phase angle according to the calculation formula for the voltage amplitude and the calculation formula for the phase angle.

6. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: After determining the topological structure of the distribution network system, the method also includes modeling the topological structure of the distribution network system and converting the graphic information into data information.

7. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: The assumption of AC power flow is that the three-phase distribution network is balanced, cosθ ij ≈1, sinθ ij ≈θ ij .

8. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: The mapping relationship matrix between node net power and node voltage amplitude and phase angle is singular. In order to solve its inverse matrix, the two rows and two columns where the reference node is located need to be deleted.

9. The method for calculating AC power flow in distribution network based on power generation load transfer factor according to claim 1, characterized in that: The generation load transfer factor depends only on the distribution network system topology and line parameters.

10. A system for calculating AC power flow in a distribution network based on the power generation load transfer factor according to any one of claims 1 to 9, characterized in that: include: A model building module is configured to: determine the topology of the distribution network system, and obtain a linear AC power flow model by combining the apparent power of the branch, the voltage amplitude and the phase angle at the node; A reference selection module is configured to: select a reference point, determine a reference voltage amplitude and a reference voltage phase angle; The first calculation module is configured to: express the node net power by the power flow of the branch connected to it according to Kirchhoff's law, and combine it with the linear AC power flow model to obtain the node net power calculation formula; A second calculation module is configured to: convert the node net power calculation formula into a matrix form, and obtain a voltage amplitude calculation formula and a phase angle calculation formula according to the matrix form of the node net power calculation formula, combined with a reference voltage amplitude and a reference voltage phase angle; A third calculation module is configured to obtain a calculation formula for branch power flow according to a calculation formula for voltage amplitude, a calculation formula for phase angle, a linear AC power flow model, and a calculation formula for power generation load transfer factor; The power flow output module is configured to obtain the branch power flow according to the calculation formula of the branch power flow.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in the method for calculating AC power flow in a distribution network based on a power generation load transfer factor as described in any one of claims 1 to 9 are implemented.

12. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the method for calculating AC power flow in a distribution network based on a power generation load transfer factor as described in any one of claims 1 to 9 are implemented.

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