Regional and county-level power grid typical wiring mode comparison and selection method and device under carbon reduction demand

Abstract

The invention relates to a method for comparing and selecting typical wiring modes of a district and county-level power grid under a carbon reduction demand. The method comprises the following steps: carrying out graphic modeling on typical wiring modes of multiple voltage levels of the district and county-level power grid; carrying out typical wiring mode load flow calculation; constructing a power matrix; constructing a carbon emission intensity matrix; calculating a carbon emission index of each typical wiring mode; and comparing and selecting typical wiring modes of the district and county-level power grid. According to the method, carbon reduction requirements are taken as a target, carbon emission calculation is carried out on multiple typical wiring modes by building a graphic model, setting boundary conditions and utilizing an electrical carbon conduction mechanism, carbon emission conditions of different wiring modes are accurately quantified, and low-carbon emission sequencing of different wiring modes is provided for district and county-level power grids through transverse comparison; according to the method, the problem that the carbon reduction target is difficult to quantify in the power grid planning is solved, the carbon emission intensity of the district and county level power grid is reduced, and a reproducible and generalizable technical path is provided for the construction of a novel power system.

Description

Technical Field

[0001] The present invention relates to the technical field of low-carbon transformation of power systems, and in particular to a method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements. Background Art

[0002] The low-carbon transformation of the power system is key to achieving my country's "dual carbon" goals. As the terminal of the power system, county-level power grids directly connect to a vast number of users. The effective implementation of their low-carbon planning is crucial to achieving the carbon reduction goals of the entire power system. Grid structure is a key factor influencing carbon emissions, and the wiring pattern is a fundamental reflection of this structure. Traditional wiring, however, focuses on meeting regional energy consumption, primarily considering safety, reliability, and economic constraints. It ignores the carbon reduction needs of the power system, fails to consider the differences in carbon emissions between different wiring patterns, and lacks clear carbon assessment standards. This makes it difficult to effectively integrate and guide low-carbon technologies, such as energy storage configuration and intelligent soft switching applications, at the grid level. Consequently, the physical structure of the grid itself fails to provide strong support for deep carbon reduction and may even become a bottleneck in the low-carbon transition.

[0003] Under the background of "dual carbon", how to select a lower-carbon wiring mode for construction or transformation while ensuring the safety, reliability and economy of the power system and reduce the carbon emission level of district and county-level distribution networks is the key direction of district and county-level power grid low-carbon planning and an effective guarantee for achieving the dual carbon goals. Summary of the Invention

[0004] In order to solve the problem of the lack of a method for selecting distribution network wiring modes under the carbon reduction demand in the context of "dual carbon", the primary purpose of the present invention is to provide a method for using a graphical modeling method to obtain the carbon emissions of different typical wiring modes based on the electric-carbon conduction mechanism, rank the carbon emissions by comparison, and provide a method for comparing typical wiring modes of district and county power grids under the carbon reduction demand of the preferred wiring mode for low-carbon construction of district and county power grids.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for comparing and selecting typical connection modes of county-level power grids under the demand for carbon reduction, the method comprising the following steps in sequence:

[0006] (1) Using the graphical modeling method, a typical connection mode of multi-voltage levels of the district and county-level power grid is graphically modeled and boundary conditions are set;

[0007] (2) Based on the graphical modeling of the typical wiring mode, the typical wiring mode flow calculation is performed to obtain the node of the mth wiring mode. Active power and reactive power ;

[0008] (3) According to active power and reactive power , construct the node active flux matrix , branch flow distribution matrix , load distribution matrix , branch active power loss distribution matrix and unit injection matrix There are 5 power matrices in total;

[0009] (4) Construct a carbon emission intensity matrix based on the carbon emission intensity of each generator set ;

[0010] (5) Based on the power matrix and carbon emission intensity matrix , calculate the carbon emission index of each typical wiring mode, the carbon emission index includes load carbon flow rate and active power loss carbon flow rate ;

[0011] (6) Compare and select typical connection modes of district and county-level power grids based on carbon emission indicators.

[0012] Step (1) specifically refers to: assuming that there are M typical connection modes for the county-level power grid, graphically modeling the typical connection modes of the county-level power grid with multiple voltage levels using a graphical modeling method, displaying the connection relationship between the components of each typical connection mode, and setting boundary conditions, wherein the boundary conditions include that the total load of the M typical connection modes is the same, the transformer scale model is the same, the total length of each group of connection modes is the same, the line model is the same, and the power supply carbon emission factor is the same.

[0013] Step (2) specifically refers to: the node of the mth wiring mode Active power and reactive power The equilibrium equations are expressed as:

[0014] ;

[0015] Where: Node of the mth wiring mode The voltage amplitude; Node of the mth wiring mode The voltage amplitude; The branch of the mth wiring mode The voltage phase angle difference between the two ends; 、 They are the branches of the mth wiring mode Conductance and susceptance at both ends; For all AND nodes of the mth wiring pattern The set of end nodes of connected branches; .

[0016] Step (3) specifically refers to: the node active flux matrix for:

[0017] ;

[0018] Where: It is used to describe the absolute amount of active power flow into the node under the power flow direction of the mth connection mode, N is the number of nodes, mid-diagonal terms Node of the mth wiring mode The active flux, ;

[0019] The branch power flow distribution matrix for:

[0020] ;

[0021] Where: It is used to describe the active power flow distribution of the mth connection mode. All non-diagonal elements of the matrix are The branch of the mth wiring mode The current flowing through ;

[0022] The load distribution matrix for:

[0023] ;

[0024] Where: Used to describe the load distribution of the mth connection mode, the diagonal elements of the matrix Node of the mth wiring mode The meritorious trend;

[0025] The branch active power loss distribution matrix for:

[0026] ;

[0027] Where: Used to describe the active power loss distribution of the mth connection mode; is a matrix The off-diagonal elements of , indicating a branch Active power loss of the power flow, diagonal elements is 0;

[0028] The unit injection matrix for:

[0029] ;

[0030] Where: The matrix elements of The definition is: when A power supply is connected to the node of the mth wiring mode Injection node When the active power flow is p, ,otherwise ; K is the number of generator sets in the mth connection mode, .

[0031] Step (4) specifically refers to: the carbon emission intensity matrix for:

[0032] ;

[0033] Where K is the number of generator sets in the mth connection mode, ; N is the number of nodes; is the carbon emission intensity of the generator set with the mth connection mode.

[0034] Step (5) specifically refers to: according to the node active flux matrix , branch flow distribution matrix , unit injection matrix and carbon emission intensity matrix , calculate the node carbon potential matrix :

[0035] ;

[0036] According to the node carbon potential matrix , calculate the branch carbon flow density matrix :

[0037] ;

[0038] Where: It is used to describe the carbon flow density of each line in the system; H is the matrix that represents the relationship between the branch tidal current and the direction of the flow. , if the node With node There are branches connecting them. , and flows into the node through this branch The forward active power flow of is not zero, then the element , If it flows through a branch The active power flow is the reverse flow, that is, the current flows from the load to the substation, then , ;

[0039] According to the load distribution matrix and the node carbon potential matrix , calculate the load carbon flow rate :

[0040] ;

[0041] According to the branch carbon flow density matrix and branch active power loss distribution matrix , calculate the active power loss carbon flow rate :

[0042] .

[0043] Step (6) specifically refers to: the load carbon flow rate of the mth wiring mode load carbon flow rate and branch active power loss carbon flow rate Sum up and get the carbon emissions of the mth wiring mode for:

[0044] ;

[0045] Similarly, the carbon emissions of all connection modes are obtained and ranked, and the connection mode with the lowest carbon emissions is selected as the preferred target T for low-carbon construction of typical connection modes of district and county power grids:

[0046] ;

[0047] Where M is the type of typical wiring mode.

[0048] Another object of the present invention is to provide an electronic device, comprising:

[0049] processor; and

[0050] A memory, wherein computer program instructions are stored in the memory, and when the computer program instructions are executed by the processor, the processor executes the method for comparing and selecting typical wiring modes of district and county-level power grids under the carbon reduction demand as described above.

[0051] The present invention also provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the processor executes the method for comparing and selecting typical wiring modes of district and county-level power grids under the carbon reduction demand as described above.

[0052] It can be seen from the above technical scheme that the beneficial effects of the present invention are: First, the present invention takes carbon reduction demand as the goal, builds a graphical model, sets boundary conditions, and uses the electric-carbon conduction mechanism to calculate the carbon emissions of various typical connection modes, accurately quantify the carbon emissions of different connection modes, and provide low-carbon rankings of different connection modes for county-level power grids through horizontal comparison; Second, in order to make up for the lack of distribution network connection mode selection method under the carbon reduction demand in the "dual carbon" background, the present invention proposes a typical connection mode comparison method for county-level power grids under carbon reduction demand, which solves the problem that carbon reduction targets in power grid planning are difficult to quantify and implement, reduces the carbon emission intensity of county-level power grids, and provides a replicable and popularizable technical path for the construction of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a flow chart of the method of the present invention;

[0054] Figure 2 It is a schematic diagram of a single-chain graphical model;

[0055] Figure 3 It is a schematic diagram of a single-loop graphical model;

[0056] Figure 4 It is a schematic diagram of a double-radiation graphic model;

[0057] Figure 5 It is a single chain flow diagram;

[0058] Figure 6 It is a single-loop power flow diagram;

[0059] Figure 7 It is a double radiation power flow diagram;

[0060] Figure 8 is a single-chain carbon flow diagram;

[0061] Figure 9 is a single-ring carbon flow diagram;

[0062] Figure 10 This is a double radiation carbon flow diagram. DETAILED DESCRIPTION

[0063] like Figure 1 As shown, a method for comparing and selecting typical connection modes of county-level power grids under carbon reduction requirements includes the following steps in sequence:

[0064] (1) Using the graphical modeling method, a typical connection mode of multi-voltage levels of the district and county-level power grid is graphically modeled and boundary conditions are set;

[0065] (2) Based on the graphical modeling of the typical wiring mode, the typical wiring mode flow calculation is performed to obtain the node of the mth wiring mode. Active power and reactive power ;

[0066] (3) According to active power and reactive power , construct the node active flux matrix , branch flow distribution matrix , load distribution matrix , branch active power loss distribution matrix and unit injection matrix There are 5 power matrices in total;

[0067] (4) Construct a carbon emission intensity matrix based on the carbon emission intensity of each generator set ;

[0068] (5) Based on the power matrix and carbon emission intensity matrix , calculate the carbon emission index of each typical wiring mode, the carbon emission index includes load carbon flow rate and active power loss carbon flow rate ;

[0069] (6) Compare and select typical connection modes of district and county-level power grids based on carbon emission indicators.

[0070] Step (1) specifically refers to: assuming that there are M typical connection modes for the county-level power grid, graphically modeling the typical connection modes of the county-level power grid with multiple voltage levels using a graphical modeling method, displaying the connection relationship between the components of each typical connection mode, and setting boundary conditions, wherein the boundary conditions include that the total load of the M typical connection modes is the same, the transformer scale model is the same, the total length of each group of connection modes is the same, the line model is the same, and the power supply carbon emission factor is the same.

[0071] Step (2) specifically refers to: the node of the mth wiring mode Active power and reactive power The equilibrium equations are expressed as:

[0072] ;

[0073] Where: Node of the mth wiring mode The voltage amplitude; Node of the mth wiring mode The voltage amplitude; The branch of the mth wiring mode The voltage phase angle difference between the two ends; 、 They are the branches of the mth wiring mode Conductance and susceptance at both ends; For all AND nodes of the mth wiring pattern The set of end nodes of connected branches; .

[0074] Step (3) specifically refers to: the node active flux matrix for:

[0075] ;

[0076] Where: It is used to describe the absolute amount of active power flow into the node under the power flow direction of the mth connection mode, N is the number of nodes, mid-diagonal terms Node of the mth wiring mode The active flux, ;

[0077] The branch power flow distribution matrix for:

[0078] ;

[0079] Where: It is used to describe the active power flow distribution of the mth connection mode. All non-diagonal elements of the matrix are The branch of the mth wiring mode The current flowing through ;

[0080] The load distribution matrix for:

[0081] ;

[0082] Where: Used to describe the load distribution of the mth connection mode, the diagonal elements of the matrix Node of the mth wiring mode The meritorious trend;

[0083] The branch active power loss distribution matrix for:

[0084] ;

[0085] Where: Used to describe the active power loss distribution of the mth connection mode; is a matrix The off-diagonal elements of , indicating a branch Active power loss of the power flow, diagonal elements is 0;

[0086] The unit injection matrix for:

[0087] ;

[0088] Where: The matrix elements of The definition is: when A power supply is connected to the node of the mth wiring mode Injection node When the active power flow is p, ,otherwise ; K is the number of generator sets in the mth connection mode, .

[0089] Step (4) specifically refers to: the carbon emission intensity matrix for:

[0090] ;

[0091] Where K is the number of generator sets in the mth connection mode, ; N is the number of nodes; is the carbon emission intensity of the generator set with the mth connection mode.

[0092] Step (5) specifically refers to: according to the node active flux matrix , branch flow distribution matrix , unit injection matrix and carbon emission intensity matrix , calculate the node carbon potential matrix :

[0093] ;

[0094] According to the node carbon potential matrix , calculate the branch carbon flow density matrix :

[0095] ;

[0096] Where: It is used to describe the carbon flow density of each line in the system; H is the matrix that represents the relationship between the branch tidal current and the direction of the flow. , if the node With node There are branches connecting them. , and flows into the node through this branch The forward active power flow of is not zero, then the element , If it flows through a branch The active power flow is the reverse flow, that is, the current flows from the load to the substation, then , ;

[0097] According to the load distribution matrix and the node carbon potential matrix , calculate the load carbon flow rate :

[0098] ;

[0099] According to the branch carbon flow density matrix and branch active power loss distribution matrix , calculate the active power loss carbon flow rate :

[0100] .

[0101] Step (6) specifically refers to: the load carbon flow rate of the mth wiring mode load carbon flow rate and branch active power loss carbon flow rate Sum up and get the carbon emissions of the mth wiring mode for:

[0102] ;

[0103] Similarly, the carbon emissions of all connection modes are obtained and ranked, and the connection mode with the lowest carbon emissions is selected as the preferred target T for low-carbon construction of typical connection modes of district and county power grids:

[0104] ;

[0105] Where M is the type of typical wiring mode.

[0106] Example 1

[0107] Three typical wiring modes of 110kV to 35kV levels in district and county power grids are selected, mainly single chain, single ring and double radial wiring. Each wiring group consists of one or two 110kV substations and two 35kV substations, without clean energy output. Using the graphical modeling method, single chain graphical model, single ring graphical model and double radial graphical model are constructed to show the connection relationship of components in each typical wiring mode, such as Figure 2 、 3 ,4. Set the boundary conditions, specifically, the total line load is 23.4MW, the total length of each line group is 53.79km, the line model is LGJ-185 conductor, the 110kV substation transformer capacity is 50MVA, and the 35kV transformer capacity is 10MVA.

[0108] according to Figure 2 、 3 4. The graphical model constructed is used to carry out the flow calculation. The calculation results are as follows Figure 5 、 Figure 6 、 Figure 7 shown.

[0109] Based on the power flow calculation results, a power matrix was constructed. Combined with the carbon emission intensity of each generator set, a carbon emission intensity matrix was constructed. The average carbon emission factor of the large power grid was calculated as 763gCO2 / kWh. The carbon emission indicators of each typical connection mode were calculated, including the load carbon flow rate and the active power loss carbon flow rate, as shown below:

[0110] according to Figure 5 The flow calculation results shown in the figure show that the load carbon flow rate in this mode is 17.854tCO2 / h, the active loss carbon flow rate is 1.171tCO2 / h, and the carbon flow diagram is shown in the figure. Figure 8 shown.

[0111] according to Figure 6 The flow calculation results shown in the figure show that the load carbon flow rate in this mode is 17.854tCO2 / h, the active power loss carbon flow rate is 1.162tCO2 / h, and the carbon flow diagram is shown in the figure. Figure 9 shown.

[0112] according to Figure 7 The flow calculation results shown in the figure show that the load carbon flow rate in this mode is 17.854tCO2 / h, the active loss carbon flow rate is 0.697tCO2 / h, and the carbon flow diagram is shown in the figure. Figure 10 shown.

[0113] The carbon flow rate of the load and the carbon flow rate of the branch active power loss of the three connection modes were summed to obtain the carbon emissions of each connection mode, and the modes were ranked. The connection mode with the lowest carbon emissions was selected as the preferred target for low-carbon construction of typical connection modes for district and county power grids. It can be seen that in the 110kV to 35kV power grid, the dual-radiation networking mode has the lowest carbon emissions, followed by the single ring, and finally the single chain. The difference in carbon emissions between the single ring and the single chain is small. In order to reduce the carbon emissions of district and county power grids, when planning and constructing the 110kV to 35kV level, the networking mode in the near term and target year should be based on dual radiation, supplemented by single ring and single chain. The details are shown in Table 1 below:

[0114] Table 1 Carbon emissions from typical connection modes of district and county-level power grids

[0115]

[0116] To sum up, the present invention takes carbon reduction demand as its goal, builds a graphical model, sets boundary conditions, and utilizes the electric-carbon conduction mechanism to measure carbon emissions for a variety of typical connection modes, accurately quantifies the carbon emissions of different connection modes, and provides low-carbon rankings of different connection modes for county-level power grids through horizontal comparison; in order to make up for the lack of distribution network connection mode selection method under the carbon reduction demand in the "dual carbon" background, the present invention proposes a typical connection mode comparison method for county-level power grids under carbon reduction demand, which solves the problem that carbon reduction targets in power grid planning are difficult to quantify and implement, reduces the carbon emission intensity of county-level power grids, and provides a replicable and popularizable technical path for the construction of new power systems.

[0117] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for comparing and selecting typical connection modes of county-level power grids under the demand for carbon reduction, characterized by: The method comprises the following steps in sequence: (1) Using the graphical modeling method, a typical connection mode of multi-voltage levels of the district and county-level power grid is graphically modeled and boundary conditions are set; (2) Based on the graphical modeling of the typical wiring mode, the typical wiring mode flow calculation is performed to obtain the node of the mth wiring mode. Active power and reactive power ; (3) According to active power and reactive power , construct the node active flux matrix , branch flow distribution matrix , load distribution matrix , branch active power loss distribution matrix and unit injection matrix There are 5 power matrices in total; (4) Construct a carbon emission intensity matrix based on the carbon emission intensity of each generator set ; (5) Based on the power matrix and carbon emission intensity matrix , calculate the carbon emission index of each typical wiring mode, the carbon emission index includes load carbon flow rate and active power loss carbon flow rate ; (6) Compare and select typical connection modes of district and county-level power grids based on carbon emission indicators.

2. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (1) specifically refers to: assuming that there are M typical connection modes for the county-level power grid, graphically modeling the typical connection modes of the county-level power grid with multiple voltage levels using a graphical modeling method, displaying the connection relationship between the components of each typical connection mode, and setting boundary conditions, wherein the boundary conditions include that the total load of the M typical connection modes is the same, the transformer scale model is the same, the total length of each group of connection modes is the same, the line model is the same, and the power supply carbon emission factor is the same.

3. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (2) specifically refers to: the node of the mth wiring mode Active power and reactive power The equilibrium equations are expressed as: ； Where: Node of the mth wiring mode The voltage amplitude; Node of the mth wiring mode The voltage amplitude; The branch of the mth wiring mode The voltage phase angle difference between the two ends; 、 They are the branches of the mth wiring mode Conductance and susceptance at both ends; For all AND nodes of the mth wiring pattern The set of end nodes of connected branches; .

4. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (3) specifically refers to: the node active flux matrix for: ； Where: It is used to describe the absolute amount of active power flow into the node under the power flow direction of the mth connection mode, N is the number of nodes, mid-diagonal terms Node of the mth wiring mode The active flux, ; The branch power flow distribution matrix for: ； Where: It is used to describe the active power flow distribution of the mth connection mode. All non-diagonal elements of the matrix are The branch of the mth wiring mode The current flowing through ; The load distribution matrix for: ； Where: Used to describe the load distribution of the mth connection mode, the diagonal elements of the matrix Node of the mth wiring mode The meritorious trend; The branch active power loss distribution matrix for: ； Where: Used to describe the active power loss distribution of the mth connection mode; is a matrix The off-diagonal elements of , indicating a branch Active power loss of the power flow, diagonal elements is 0; The unit injection matrix for: ； Where: The matrix elements of The definition is: when A power supply is connected to the node of the mth wiring mode Injection node When the active power flow is p, ,otherwise ; K is the number of generator sets in the mth connection mode, .

5. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (4) specifically refers to: the carbon emission intensity matrix for: ； Where K is the number of generator sets in the mth connection mode, ; N is the number of nodes; is the carbon emission intensity of the generator set with the mth connection mode.

6. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (5) specifically refers to: according to the node active flux matrix , branch flow distribution matrix , unit injection matrix and carbon emission intensity matrix , calculate the node carbon potential matrix : ； According to the node carbon potential matrix , calculate the branch carbon flow density matrix : ； Where: Used to describe the carbon flow density of each circuit in the system; H is the matrix representing the relationship between branch current flow directions, , if the node With node There are branches connecting them. , and flows into the node through this branch The forward active power flow of is not zero, then the element , If it flows through a branch The active power flow is the reverse flow, that is, the current flows from the load to the substation, then , ; According to the load distribution matrix and the node carbon potential matrix , calculate the load carbon flow rate : ； According to the branch carbon flow density matrix and branch active power loss distribution matrix , calculate the active power loss carbon flow rate : 。 7. The method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements according to claim 1 is characterized by: Step (6) specifically refers to: the load carbon flow rate of the mth wiring mode load carbon flow rate and branch active power loss carbon flow rate Sum up and get the carbon emissions of the mth wiring mode for: ； Similarly, the carbon emissions of all connection modes are obtained and ranked, and the connection mode with the lowest carbon emissions is selected as the preferred target T for low-carbon construction of typical connection modes of district and county power grids: ； Where M is the type of typical wiring mode.

8. An electronic device comprising: processor; as well as A memory, wherein computer program instructions are stored in the memory, and when the computer program instructions are executed by the processor, the processor executes the method for comparing and selecting typical wiring modes of district and county-level power grids under carbon reduction requirements according to any one of claims 1 to 7.

9. A computer-readable storage medium having computer program instructions stored thereon, wherein when the computer program instructions are executed by a processor, the processor is caused to execute the method for comparing and selecting typical connection modes of district and county-level power grids under carbon reduction requirements as described in any one of claims 1 to 7.

Images