Node carbon emission factor calculation method and system for power grid outage emergencies

Abstract

The present invention discloses a method and system for calculating node carbon emission factors for power grid power outage emergencies, which belongs to the field of power systems. The method for calculating node carbon emission factors for power grid power outage emergencies includes: obtaining node injection power information, calculating branch currents under normal power grid operation, and constructing a branch current distribution matrix and a node active flux matrix to calculate the node carbon emission factors under normal power grid operation; extending the calculation process of node carbon emission factors under normal power grid operation to power grid disconnection emergencies, and introducing a line disconnection distribution factor to represent the branch currents under disconnection emergencies, and calculating the node carbon emission factors under emergencies. This method is suitable for carbon emission analysis under N-1 emergency events (such as line disconnections) in power systems, and can dynamically evaluate changes in carbon emissions of the system under fault conditions, supporting the low-carbon and safe operation of power systems.

Description

Technical Field

[0001] The present invention belongs to the field of power systems, and in particular relates to a method and system for calculating node carbon emission factors for power grid power outage emergencies. Background Art

[0002] With the advancement of global low-carbon development goals, the deep integration of electricity and carbon markets has become a key path to achieving a green transformation of the energy system. The introduction of carbon flow theory provides an important theoretical foundation for establishing the relationship between power generation, electricity consumption, and carbon emissions, making carbon emission accounting in power systems more scientific and refined. Accurately accounting for electricity carbon emissions is not only a core requirement for the low-carbon transformation of power systems, but also a crucial prerequisite for the effective operation of carbon markets. In power systems, user-side electricity consumption directly affects carbon emissions. However, traditional carbon emission accounting methods often fail to reflect the dynamic impact of changes in user-side electricity consumption on carbon emissions, nor can they accurately assess changes in power system carbon emissions during emergencies (such as N-1 outages). Power outages alter power transmission paths, thereby affecting the spatiotemporal distribution of carbon emissions. However, existing research has not established a dynamic response model for carbon flow under fault conditions, making it impossible to quantify the impact of line outages on system carbon flows. Grid restoration after faults must balance safety and economic efficiency, but carbon emissions are often overlooked. Due to the lack of fault carbon flow analysis tools, dispatch strategies struggle to achieve multi-objective optimization across the "safety, economy, and low carbon" framework in emergency control.

[0003] Currently, the Line Shift Factor (SF) and Line Outage Distribution Factor (LODF) are widely used in power system security analysis to assess post-fault power flow redistribution. However, these methods focus solely on electrical quantities (such as power and voltage) and are not integrated with carbon flow models. Therefore, a new approach that integrates grid fault analysis and carbon flow tracking is urgently needed to accurately calculate carbon emissions in power outage scenarios and support the safe and low-carbon operation of power systems. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a method and system for calculating node carbon emission factors for power grid power outage emergencies, thereby solving the problems in the prior art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The calculation method of the node carbon emission factor for power grid outage emergency events includes the following steps:

[0007] Obtain node injection power information, calculate branch power flows under normal grid operation, and construct branch power flow distribution matrices and node active flux matrices to calculate node carbon emission factors under normal grid operation.

[0008] The calculation process of node carbon emission factors under normal grid operation is extended to grid emergency events, and the line disconnection distribution factor is introduced to represent the branch flow under emergency events, and the node carbon emission factors under emergency events are calculated.

[0009] Furthermore, the branch power flow calculation formula under normal operation of the power grid is:

[0010]

[0011] Where, is the branch power flow vector under normal operation; is the line transfer factor, which represents the branch power increment matrix when unit power is injected into the node; Inject power vectors into nodes.

[0012] Furthermore, the branch power flow distribution matrix The expression is:

[0013]

[0014] Where, is an auxiliary function;

[0015] The node active flux matrix The expression is:

[0016]

[0017] Where, It is an N+K order row vector, and all elements in the row vector are equal to 1; is the K×N order generator injection distribution matrix; K is the number of generators;

[0018] Furthermore, the node carbon emission factor under normal operation of the power grid is The expression is:

[0019]

[0020] Where, is the generator carbon emission intensity vector.

[0021] Furthermore, the branch power flow expression under emergency events is:

[0022]

[0023] Where, Offline for emergencies The trend; and They are observation line and accident line respectively; and They are Lines in the matrix and The row where it is located; A line with unit power flow Disconnect the line power increase.

[0024] Furthermore, the calculation formula for the node carbon emission factor under emergency events is:

[0025]

[0026] Where, is the node carbon emission factor under emergency events.

[0027] The node carbon emission factor calculation system for power grid outage emergencies includes:

[0028] Normal grid node carbon emission factor calculation module: obtains node injection power information, calculates branch power flows under normal grid operation, and constructs branch power flow distribution matrix and node active flux matrix to calculate node carbon emission factors under normal grid operation;

[0029] Module for calculating carbon emission factors at disconnected power grid nodes: This module extends the calculation process of node carbon emission factors under normal grid operation to grid emergencies, introduces line disconnection distribution factors to represent branch flows under emergencies, and calculates node carbon emission factors under emergencies.

[0030] A computer storage medium stores a readable program, which, when executed by a processor, can execute the above-mentioned node carbon emission factor calculation method for power grid power outage emergencies.

[0031] An electronic device comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0032] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned node carbon emission factor calculation method for power grid power outage emergencies.

[0033] A computer program product includes computer instructions, wherein the computer instructions instruct a computing device to execute operations corresponding to the above-mentioned method for calculating node carbon emission factors for power grid power outage emergencies.

[0034] Beneficial effects of the present invention:

[0035] 1. The node carbon emission factor calculation method for power grid outage emergencies in the present invention can accurately calculate the carbon emission factors of power system nodes, quantify the impact of node power injection changes on carbon emissions, and provide a scientific basis for the carbon emission characteristics of the power system.

[0036] 2. The method of the present invention is also applicable to carbon emission analysis under N-1 emergency events (such as line disconnection) in the power system. It can dynamically evaluate the changes in carbon emissions of the system under fault conditions and support the low-carbon and safe operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 is a flow chart of the method for calculating the node carbon emission factor of the present invention;

[0039] Figure 2 It is the IEEE30-node power grid topology diagram;

[0040] Figure 3 This is a schematic diagram of the calculation results of the node carbon emission factor under normal grid operation and line disconnection emergencies. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figure 1 As shown in FIG, the method for calculating the node carbon emission factor for power grid outage emergencies includes the following steps:

[0044] S1, obtains node injection power information, calculates branch power flows under normal grid operation, and constructs branch power flow distribution matrix and node active flux matrix to calculate node carbon emission factors under normal grid operation;

[0045] S11, the branch power flow calculation formula under normal operation of the power grid is:

[0046]

[0047] Where, is the branch power flow vector under normal operation; is the line transfer factor, which represents the branch power increment matrix when unit power is injected into the node; Inject power vectors into nodes.

[0048] S12, the step of constructing a branch power flow distribution matrix and a node active flux matrix includes:

[0049] 1) Build Order branch power flow distribution matrix , where N represents the number of grid nodes;

[0050] For the node i and nodes j (i, j = 1, 2, 3, ..., N) If there is a branch connected by a node i Flow Node j The positive trend is , ;in, for Branch in the matrix i- j If the branch flow is opposite, then , ; In other cases In addition, the branch flow distribution matrix All diagonal elements in are 0, that is, .

[0051] In order to better show the relationship between variables, an auxiliary function is introduced Make Can be and express.

[0052] .

[0053] 2) Construct node active flux matrix ;

[0054] is an N-order diagonal matrix, representing the injection power of each node; itsi The row diagonal elements are equal to and No. i Sum of column elements:

[0055]

[0056] Where, It is an N+K order row vector, and all elements in the row vector are equal to 1; is the K×N order generator injection distribution matrix; K is the number of generators;

[0057] S13, calculate the node carbon emission factor under normal operation of the power grid;

[0058] The carbon emissions of a node are equal to the sum of the carbon emissions of the branches flowing into the node and the carbon emissions of the generators connected to the node. Based on this property, the following formula can be obtained:

[0059]

[0060] Where, is the node carbon emission factor vector; is the generator carbon emission intensity vector.

[0061] In summary, the carbon emission factor calculation formula for all nodes in the power grid is as follows:

[0062] .

[0063] According to the properties of carbon flow theory, the branch carbon flow density can be replaced by the carbon emission factor of the initial node of the branch:

[0064]

[0065] Where, is the branch carbon flow density; It is the branch flow direction matrix and provides the initial node information of the branch flow.

[0066] S2, extends the calculation process of the node carbon emission factor under normal grid operation in S1 to grid emergency events, introduces the line disconnection distribution factor (LODF) to represent the branch power flow under emergency events, and calculates the node carbon emission factor under emergency events;

[0067] The branch power flow calculation formula under emergency events is:

[0068]

[0069] Where, Offline for emergencies The trend; and They are observation line and accident line respectively; and They are Lines in the matrix and The row where it is located; A line with unit power flow Disconnect the line power increase.

[0070] Nodal carbon emission factors under emergency events The calculation formula is:

[0071]

[0072] Branch carbon flow density during emergencies for:

[0073] .

[0074] Based on similar inventive concepts, an embodiment of the present invention further provides a computer storage medium storing a readable program, which, when executed by a processor, can execute the above-mentioned node carbon emission factor calculation method for power grid power outage emergencies.

[0075] Based on similar inventive concepts, an embodiment of the present invention provides an electronic device, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0076] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned node carbon emission factor calculation method for power grid power outage emergencies.

[0077] Based on similar inventive concepts, an embodiment of the present invention further provides a computer program product, including computer instructions, which instruct a computing device to execute operations corresponding to the above-mentioned node carbon emission factor calculation method for power grid power outage emergencies.

[0078] Example 2

[0079] Based on the node carbon emission factor calculation method for power grid outage emergencies proposed in Example 1, this embodiment proposes a node carbon emission factor calculation system for power grid outage emergencies, including:

[0080] Normal grid node carbon emission factor calculation module: obtains node injection power information, calculates branch power flows under normal grid operation, and constructs branch power flow distribution matrix and node active flux matrix to calculate node carbon emission factors under normal grid operation;

[0081] Module for calculating carbon emission factors at disconnected power grid nodes: This module extends the calculation process of node carbon emission factors under normal grid operation to grid emergencies, introduces line disconnection distribution factors to represent branch flows under emergencies, and calculates node carbon emission factors under emergencies.

[0082] Example 3

[0083] In this embodiment, the calculation method proposed in Example 1 is simulated to verify the effect of the method;

[0084] This paper takes the IEEE 30-node power grid as an example, the topology diagram is as follows Figure 2 As shown in the figure, Node 1 is configured as a coal-fired unit with a carbon intensity factor of 0.875 tCO2 / MWh; Nodes 2, 23, and 27 are configured as gas-fired units with carbon intensity factors of 0.525 tCO2 / MWh, 0.52 tCO2 / MWh, and 0.57 tCO2 / MWh, respectively; and Nodes 13 and 22 are configured as renewable energy units with a carbon intensity factor of 0. Except for the generator node, all other nodes are configured as load nodes.

[0085] Under normal operation of the power grid, the calculation results of the node carbon emission factor are as follows: Figure 3 As shown in the figure, the node carbon emission factor is related to the distribution of grid power flow. Nodes near high-carbon-emitting generators tend to have higher node carbon emission intensities, while nodes near renewable energy generators generally have significantly lower carbon intensities.

[0086] Traverse the grid N-1 emergency event, and use the node carbon emission factor calculation method for grid power outage emergency events proposed in Example 1 to calculate the node carbon emission factor. In this example, the line 6 disconnection is used as an example, and the node carbon emission factor calculation result is as follows: Figure 3 By comparing the node carbon emission factors of Line 6 during normal operation and during an emergency, we can see that the line outage caused significant changes in the carbon emission factors of specific nodes. Notably, the carbon emission factor of node 6 increased, while the carbon emission factor of node 7 decreased accordingly.

[0087] In summary, the distribution of node carbon emission factors is closely related to the distribution of power flow in the grid, exhibiting significant dynamic characteristics, particularly when the grid's operating state changes. Research has shown that nodes near high-carbon-emitting units have higher carbon emission intensities, while nodes connected to renewable energy have lower carbon emission factors, confirming the positive contribution of clean energy to local carbon emission reduction. Under N-1 emergency events, changes in network topology and power flow distribution can further lead to a redistribution of node carbon emission factors. The carbon emission factors of some nodes increase due to changes in power supply routes, while those of others may decrease due to power flow shifts to low-carbon power sources. This phenomenon demonstrates that grid reliability events not only affect the safe operation of the system but can also indirectly reshape the spatial distribution of carbon emissions by altering power transmission routes. This provides an important basis for low-carbon grid planning and emergency dispatch, which requires the coordinated optimization of both safety constraints and carbon emission impacts.

[0088] The method of the present invention can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as a CDROM, RAM, floppy disk, hard disk or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-temporary machine-readable medium downloaded over a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a special-purpose processor or programmable or special-purpose hardware (such as an ASIC or FPGA). It will be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by a computer, a processor or hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown here, the execution of the code converts the general-purpose computer into a special-purpose computer for executing the method shown here.

[0089] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of 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, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A method for calculating node carbon emission factors for power grid outage emergencies, characterized in that: The following steps are involved: Obtain node injection power information, calculate branch power flows under normal grid operation, and construct branch power flow distribution matrices and node active flux matrices to calculate node carbon emission factors under normal grid operation. The calculation process of node carbon emission factors under normal grid operation is extended to grid emergency events, and the line disconnection distribution factor is introduced to represent the branch flow under emergency events, and the node carbon emission factors under emergency events are calculated; The branch power flow calculation formula under normal operation of the power grid is: PL=SF×P inj Where PL is the branch power flow vector under normal operation; SF is the line transfer factor, which represents the branch power increment matrix when unit power is injected into the node; P inj Inject power vectors into nodes; The branch power flow distribution matrix P B The expression is: P B =ξ B (SF×P inj ) Where, ξ B (·) is an auxiliary function; The node active flux matrix P N The expression is: P N =diag(ζ N [x] B (SF×P inj );P G ]) Where, ζ N It is an N+K order row vector, and all elements in the row vector are equal to 1; P G is the K×N order generator injection distribution matrix; K is the number of generators.

2. The method for calculating node carbon emission factors for power grid outage emergencies according to claim 1, characterized in that: Node carbon emission factor E under normal grid operation N The expression is: Where, E G is the generator carbon emission intensity vector.

3. The method for calculating node carbon emission factors for power grid outage emergencies according to claim 2, characterized in that: The branch power flow expression under emergency events is: Where, is the power flow of line l1 under emergency events; l1 and l2 are the observation line and the accident line respectively; and are the rows where lines l1 and l2 are located in the SF matrix respectively; is the power increment of line l1 after line l2 with unit power flow is disconnected.

4. The method for calculating node carbon emission factors for power grid outage emergencies according to claim 3, characterized in that: The calculation formula for the node carbon emission factor under emergency events is: Where, E Nc is the node carbon emission factor under emergency events.

5. A node carbon emission factor calculation system for power grid outage emergencies, characterized by: include: Normal grid node carbon emission factor calculation module: obtains node injection power information, calculates branch power flows under normal grid operation, and constructs branch power flow distribution matrix and node active flux matrix to calculate node carbon emission factors under normal grid operation; Disconnected grid node carbon emission factor calculation module: This module extends the calculation process of node carbon emission factors under normal grid operation to grid emergencies, introduces line disconnection distribution factors to represent branch power flows under emergencies, and calculates node carbon emission factors under emergencies. The branch power flow calculation formula under normal operation of the power grid is: PL=SF×P inj Where PL is the branch power flow vector under normal operation; SF is the line transfer factor, which represents the branch power increment matrix when unit power is injected into the node; P inj Inject power vectors into nodes; The branch power flow distribution matrix P B The expression is: P B =ξ B (SF×P inj ) Where, ξ B (·) is an auxiliary function; The node active flux matrix P N The expression is: P N =diag(ζ N [x] B (SF×P inj );P G ]) Where, ζ N It is an N+K order row vector, and all elements in the row vector are equal to 1; P G is the K×N order generator injection distribution matrix; K is the number of generators.

6. A computer storage medium storing a readable program, characterized in that: When the program is executed by a processor, it can execute the node carbon emission factor calculation method for power grid power outage emergencies described in any one of claims 1 to 4.

7. An electronic device, characterized in that: include: A processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the node carbon emission factor calculation method for power grid power outage emergencies according to any one of claims 1 to 4.

8. A computer program product comprising computer instructions, characterized in that The computer instructions instruct the computing device to execute operations corresponding to the method for calculating node carbon emission factors for power grid power outage emergencies as described in any one of claims 1-4.

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