Consumer carbon emission accounting method based on carbon flow tracking technology

Abstract

The invention provides a consumption type carbon emission accounting method based on a carbon flow tracking technology, and the method comprises the following steps: 1, determining a carbon source and a carbon sink, and simplifying each region into a pure carbon source or a pure carbon sink; 2, determining the contribution of a carbon source to carbon sink by using a carbon flow tracking method; 3, calculating a regional carbon account according to the carbon source emission rate, and calculating the carbon emission amount of each region by using the emission rate of each region for the regional carbon account; and 4, according to the power supply structures of the different areas, evaluating the carbon emission intensity of the different areas. According to the method, the indirect carbon emission is determined by tracking the energy source of the power consumption in the power network, the transmission characteristics of power supply and the regionality of the energy structure are reflected from the perspective of power generation to consumption, and the method can be used for solving the problems of carbon accounting at the regional level and carbon intensity evaluation at the user level.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon accounting. Background Art

[0002] The power industry, a cornerstone of modern society, is a significant contributor to global greenhouse gas emissions due to its massive scale and widespread reach. As the severe challenges of global climate change become increasingly prominent, carbon emissions from electricity production and consumption have become a focus of international attention. The generation of electricity often involves the combustion of fossil fuels, which releases large amounts of greenhouse gases such as carbon dioxide, posing a serious threat to the Earth's climate system.

[0003] In the complex system of carbon accounting and carbon footprint assessment, electricity usage presents a particularly unique characteristic. First, electricity is generated in power plants, and carbon emissions from its production process often occur far from where it is consumed. This spatial separation between production and consumption poses significant challenges for the equitable allocation of emission reduction responsibilities, particularly in the context of increasingly frequent cross-border electricity trading. How to rationally allocate emission reduction tasks between countries and businesses, ensuring a balance between responsibility and benefits, has become a pressing challenge. Furthermore, the mixed nature of electricity usage complicates the assessment of the carbon footprint of products, processes, and services. Because the proportions of electricity sources (such as coal, natural gas, and renewable energy) vary across regions and time periods, and because electricity itself cannot be physically traced like a commodity, it is difficult to accurately calculate the actual carbon emissions corresponding to the electricity consumed in the production of a specific product or service. This uncertainty not only impacts the accuracy of carbon footprint assessments but also limits businesses' ability to develop effective emission reduction strategies. To address these challenges, the international community is continuously exploring new emission reduction mechanisms and accounting methods. The establishment of carbon emissions trading markets aims to incentivize businesses to reduce emissions through market mechanisms, but relying solely on trading methods is insufficient to address all issues. Innovative measures such as green certificates and low-carbon product certification have emerged. They encourage companies to adopt cleaner energy and production technologies by providing additional economic incentives or market signals, thereby indirectly reducing carbon emissions from electricity use.

[0004] However, the existing carbon emission accounting framework is mostly based on the production perspective. Although it can roughly reflect the emissions in the power production link, it is difficult to fully reflect the complexity and diversity of the power consumption end. Summary of the Invention

[0005] In order to solve the above-mentioned problems existing in the existing carbon emission accounting methods, the present invention provides a consumption-based carbon emission accounting method based on carbon flow tracking technology.

[0006] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a consumption-based carbon emission accounting method based on carbon flow tracking technology, comprising the following steps:

[0007] Determine the carbon sources and carbon sinks, simplify each region into a pure carbon source or pure carbon sink, and the carbon flow passes through the intermediate nodes from the carbon source to the final carbon sink through the directed branch to obtain the input and output relationship of each node;

[0008] Use carbon flow tracking methods to determine the contribution of carbon sources to carbon sinks;

[0009] Calculate regional carbon accounts based on carbon source emission rates. For regional carbon accounting, calculate the carbon emissions of each region using the emission rates of each region;

[0010] Evaluate the carbon emission intensity of different regions based on their power supply structure.

[0011] The emission rate of electricity supply is calculated based on the energy structure of the power output area. If there is cross-regional direct power supply, it is calculated based on the emission rate of the power supply generator. In the process of carbon flow tracking, cross-regional direct supply is eliminated. When the elimination amount is greater than the original output of the carbon source or the original input of the carbon sink, for the carbon intensity assessment at the user level, the node represents the bus. It is assumed that the generator preferentially supplies power to the load on the same bus and is merged on each bus to form a simplified network. The output of the carbon source is the carbon emissions related to the net input power of the bus, and the input of the carbon sink is the carbon emissions related to the net output power of the bus. The power supply emission rate is calculated based on the power supply generator.

[0012] Given a network with n nodes, b branches, s sources and d sinks, the output of the source and the input of the sink are P s ,P d ∈R n , process tracing identifies the following relationships:

[0013] f(P s ):P s →P d . (1)

[0014] According to the proportional sharing rule, the input and output calculation formula of each node is linear, expressed as:

[0015] P d =FP s

[0016] Where F∈R n×n is a constant matrix that can be defined as the source-to-sink contribution matrix;

[0017] In the step 2,

[0018] 1) Lossless network: Under a given network flow state, the following equation can be obtained:

[0019] P s =AP n (2)

[0020] P d =FP s , F=BA -1 (3)

[0021] Among them, P n ∈R n Indicates the total traffic of the node,

[0022] The elements of matrix A are defined as:

[0023]

[0024] Among them, i - is a set of nodes, j∈i - Indicates P ji is the input flow of node i, if ji is the output branch of node i, then P ji is a negative value.

[0025] The elements of matrix B are defined as:

[0026]

[0027] 2) Lossy network: For a lossy network, the traffic at both ends of each branch is not equal. ij |≠|P ji |, transfer the network loss to the sink, convert the lossy network into an equivalent lossless network, and derive the loss transfer equation:

[0028] ΔP d =BΔP n , ΔP ns =AΔP n (6)

[0029] Where ΔP d ∈R n is the network loss allocated to the sink, ΔP n ∈R n is the total input loss at the node, ΔP ns ∈R n is the node loss, whose elements are defined as:

[0030]

[0031] ΔP sk,ij Indicates the effect of source k on ΔP ij The contribution of ΔP ij Can be divided by source into:

[0032]

[0033] Among them, a jk (-1) It's A -1 The jth row and kth column element of ΔP sk,ij The further explanation is as follows: In the lossy network, formula (5) is modified to P n '=A -1 P s .P n '∈R n is the total node flow in the equivalent lossless network, source k to P nj 's contributions are as follows:

[0034]

[0035] According to the proportional sharing rule, the contribution of source k to the output branch of node j is the same as formula (10), so the contribution of source k to ΔP ij The contribution of satisfies (9), which can be rewritten as follows:

[0036]

[0037] Formula (7) and Formula (11) can be rewritten as follows:

[0038] ΔP ns =MΔP b (12)

[0039] ΔP b =NP s (13)

[0040] Where M∈R n×b ,N∈R n×b The elements of are defined as follows:

[0041]

[0042] Putting equations (6), (12), and (13) together, we can get the contribution of the source to the allocation loss in the sink as follows:

[0043] ΔP d =LP s ,L=BA -1 MN. (16)

[0044] L∈R n×n The columns correspond to the contribution of the corresponding source to the network loss allocated to all sinks. By adding up each column of L, we can get the total contribution rate of the corresponding source:

[0045] ΔP s =diag{LT e}P s (17)

[0046] Among them, L T is the transpose of L, e is a column vector with each element equal to 1, and the actual input of the sink in the lossy network is expressed as follows:

[0047] P d =HP s , H=BA -1 -L. (18)

[0048] According to equations (16) and (18), the final contribution of the source to the sink is expressed as follows:

[0049] P d ′=FP s , F=H+L=BA -1 . (19)

[0050] In the step (3), P s , P d ∈R n represents the output of the source and the input of the sink, i.e., the regional power output of the supplier and the regional power input of the consumer,

[0051]

[0052] Among them, S s , S d Represents the collection of carbon sources and carbon sinks, P ai ,P li Represent the local power generation and local power consumption of the region, P cij is the direct supply from region i to region j, and is negative when the direction is opposite.

[0053] P s ,P d ∈R n Participating in carbon flow tracking has the following relationships:

[0054] P d =FP S . (twenty one)

[0055] Where F∈R n×n is a constant matrix that can be defined as the source-to-sink contribution matrix;

[0056] C s ,C d ∈R n They represent the output of carbon sources and the input of carbon sinks respectively, and are converted into carbon emissions according to the regional emission rate. The regional emission rate of region i is represented by σ i To express, Csi =σ i P si , the results of carbon flow tracking are as follows:

[0057] C d =FC s . (twenty two)

[0058] The final carbon emissions account for each region is in the following form:

[0059]

[0060] Among them C ai The calculation method of C si Same, but C cij It is calculated based on the emission rates of specific generators that directly supply electricity to other areas.

[0061] In step 4, the flow tracking method is applied to carbon intensity assessment.

[0062] P s , P d Represent the output power of carbon source and the input power of carbon sink, P s , P d ∈R n The elements are:

[0063]

[0064] Among them, S s , S d is the set of generator bus and load bus in the simplified network, P a , P l ∈R n are the vectors generated and consumed by the node,

[0065] δ∈R n Represents the carbon intensity of each bus line power supply, Δ gi ∈R εi represents the emission rate of the generator on bus i, where ε i is the number of generators on the bus, thus obtaining the carbon intensity at the bus level:

[0066]

[0067] Among them, P gij represents the output of generator j on bus i, and its emission rate is δ gij , F i is the i-th row of matrix F, diag{δ} is δ∈R n The diagonal matrix of .

[0068] A device for a consumption-based carbon emission accounting method based on carbon flow tracking technology, comprising:

[0069] The carbon source and carbon sink determination module is used to simplify each region into a pure carbon source or a pure carbon sink. The carbon flow passes through the directed branch from the carbon source to the final carbon sink through the intermediate nodes to obtain the input and output relationship of each node;

[0070] A module for determining the contribution of pure carbon sources to pure carbon sinks, used to determine the contribution of pure carbon sources to pure carbon sinks;

[0071] The carbon emissions module is used for regional carbon accounting, using the emission rate of each region to calculate the carbon emissions of each region; the carbon emission intensity assessment module is used to assess the carbon emission intensity of different regions based on carbon source output, carbon sink input and carbon emission rate.

[0072] In the carbon source and carbon sink determination module, the input and output relationship of each node is obtained as follows: the emission rate of power supply is calculated based on the energy structure of the power output area. If there is cross-regional direct power supply, it is calculated based on the emission rate of the power supply generator. In the carbon flow tracking process, cross-regional direct supply is eliminated. When the elimination amount is greater than the original output of the carbon source or the original input of the carbon sink, for the user-level carbon intensity assessment, the node represents the bus. It is assumed that the generator preferentially supplies power to the load on the same bus and is merged on each bus to form a simplified network. The output of the carbon source is the carbon emissions related to the net input power of the bus, and the input of the carbon sink is the carbon emissions related to the net output power of the bus. The power supply emission rate is calculated based on the power supply generator.

[0073] Given a network with n nodes, b branches, s sources and d sinks, the output of the source and the input of the sink are P s ,P d ∈R n , process tracing identifies the following relationships:

[0074] f(P s ):P s →P d . (1)

[0075] According to the proportional sharing rule, the input and output calculation formula of each node is linear, and the input and output calculation formula of each node is expressed as:

[0076] P d =FP s

[0077] Where F∈R n×n is a constant matrix defined as the source-to-sink contribution matrix.

[0078] In the pure carbon source to pure carbon sink contribution determination module, the carbon flow tracking method is used to determine the contribution of pure carbon source to pure carbon sink. The expression is:

[0079] P d '=FP s , F=H+L=BA -1 (19)

[0080] L∈R n×n The columns correspond to the contribution of the corresponding source to the network loss distributed by all sinks, Ps∈R n represents the output of the source,

[0081] The elements of matrix A are defined as:

[0082]

[0083] Among them, i - is a set of nodes, j∈i - Indicates P ji is the input flow of node i, if ji is the output branch of node i, then P ji is a negative value;

[0084] The elements of matrix B are defined as:

[0085]

[0086] In the carbon emissions module, the method for calculating the carbon emissions of each region is as follows: s , P d ∈R n represents the output of the source and the input of the sink, i.e., the regional power output of the supplier and the regional power input of the consumer,

[0087]

[0088] Among them, S s , S d Represents the collection of carbon sources and carbon sinks, P ai ,P li Represent the local power generation and local power consumption of the region, P cij is the direct supply from region i to region j, and is negative when the direction is opposite.

[0089] P s ,P d ∈R n Participating in carbon flow tracking has the following relationships:

[0090] P d =FP S . (twenty one)

[0091] Where F∈Rn×n is a constant matrix;

[0092] C s ,C d ∈R n They represent the output of carbon sources and the input of carbon sinks respectively, and are converted into carbon emissions according to the regional emission rate. The regional emission rate of region i is represented by σ i To express, C si =σ i P si , the results of carbon flow tracking are as follows:

[0093] C d =FC s . (twenty two)

[0094] The final carbon emissions account for each region is in the following form:

[0095]

[0096] Among them C ai The calculation method of C si Same, but C cij It is calculated based on the emission rates of specific generators that directly supply electricity to other areas.

[0097] In the carbon emission intensity assessment module, the method for assessing the carbon emission intensity of different regions is as follows: Apply the flow tracking method to the carbon intensity assessment,

[0098] P s , P d Represent the output power of carbon source and the input power of carbon sink, P s , P d ∈R n The elements are:

[0099]

[0100] Among them, S s , S d is the set of generator bus and load bus in the simplified network, P a , P l ∈R n are the vectors generated and consumed by the node,

[0101] δ∈R n Represents the carbon intensity of each bus line power supply, Δ gi ∈R εi represents the emission rate of the generator on bus i, where ε i is the number of generators on the bus, thus obtaining the carbon intensity at the bus level:

[0102]

[0103] Among them, P gij represents the output of generator j on bus i, and its emission rate is δ gij , F i is the i-th row of matrix F, diag{δ} is δ∈R n The diagonal matrix of .

[0104] This consumption-based carbon emissions accounting method, based on carbon flow tracking technology, tracks the energy sources of electricity consumption within the power grid to determine indirect carbon emissions. From a "generation-to-consumption" perspective, it reflects the transmission characteristics of power supply and the regional nature of energy structures. It can also be used to address regional carbon accounting and user-level carbon intensity assessment. It can equitably distribute carbon reduction responsibilities across regions, thereby promoting regional cooperation and achieving carbon reduction goals. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Figure 1 Schematic diagram of carbon flow at the regional level of the present invention;

[0106] Figure 2 It is a regional carbon flow tracing network diagram of the present invention;

[0107] Figure 3 This is a deviation diagram of the carbon account of the present invention and the carbon emissions of each regional location. DETAILED DESCRIPTION

[0108] Based on the problems existing in the existing carbon emission accounting framework, it is necessary to develop a more refined and dynamic carbon emission accounting method for electricity use. It is necessary not only to consider the actual structure and transmission characteristics of the power network, but also to combine the temporal and spatial variation factors to establish a more scientific and comprehensive accounting system to more accurately reflect the actual carbon emissions of electricity use and provide solid data support for the formulation of effective carbon emission reduction policies.

[0109] The present invention provides a consumption-based carbon emission accounting method based on carbon flow tracking technology, comprising the following steps:

[0110] Step 1: Identify carbon sources and sinks and simplify each region into a pure carbon source or a pure carbon sink.

[0111] The power supplier and consumer are called carbon source and carbon sink respectively. Figure 1As shown, carbon flows through directed branches from carbon sources to final carbon sinks, potentially passing through multiple intermediate nodes. Carbon sources, carbon sinks, and carbon flows together constitute a carbon flow tracing network. In regional-level carbon accounting, a node represents a region. Generally, a region not only produces but also consumes electricity. The output of a carbon source is defined as the carbon emissions associated with electricity exports, and the input of a carbon sink is defined as the indirect carbon emissions from electricity imports. Therefore, each region is simplified as either a pure source or a pure sink. The emission rate of electricity supply is calculated based on the energy mix of the region exporting electricity. If there is direct inter-regional power supply, it is calculated based on the emission rate of the power generator. Inter-regional direct power supply is excluded during carbon flow tracing. During the exclusion process, node types may be converted from carbon sources to carbon sinks, or vice versa, when the amount excluded is greater than the original output of the carbon source or the original input of the carbon sink. For user-level carbon intensity assessment, nodes represent buses. Generators are assumed to preferentially supply loads on the same bus, and are merged across buses to form a simplified network. The output of a carbon source is the carbon emissions associated with the net electricity input to the bus. The input of a carbon sink is the carbon emissions associated with the net electricity output to the bus. The power supply emission rate is calculated based on the power supply generator.

[0112] Given a network with n nodes, b branches, s sources and d sinks, the output of the source and the input of the sink are represented by P s ,P d ∈R n Process tracing is used to determine the following relationships:

[0113] f(P s ):P s →P d . (1)

[0114] According to the proportional sharing rule, the input and output calculation formula of each node is linear. It can be expressed as:

[0115] P d =FP s

[0116] Where F∈R n×n is a constant matrix that can be defined as the source-to-sink contribution matrix.

[0117] Step 2: Use carbon flow tracking methods to determine the contribution of carbon sources to carbon sinks.

[0118] The key to carbon flow tracking is to calculate the matrix, that is, the contribution matrix from sources to sinks.

[0119] 1) Lossless Network: Under a given network flow state, the following equation can be obtained:

[0120] P s =AP n(2)

[0121] P d =FP s , F=BA -1 (3)

[0122] Among them, P n ∈R n It represents the total flow of the node, which is equivalent to the total input and total output of the node. The following introduces matrices A and B.

[0123] The elements of matrix A are defined as:

[0124]

[0125] Among them, i - is the set of nodes that belong to the input branch of node i. - Indicates P ji is the input flow of node i and the output flow of node j on branch ji. If ji is the output branch of node i, then P ji is a negative value.

[0126] The elements of matrix B are defined as:

[0127]

[0128] 2) Lossy Network: This section introduces the tracking technology of network loss-related emission distribution. For lossy networks, the flow at both ends of each branch is not equal. ij |≠|P ji |. A lossy network can be converted into an equivalent lossless network by transferring the network loss to the sink or source. Here we adopt the former and derive the loss transfer equation:

[0129] ΔP d =BΔP n , ΔP ns =AΔP n (6)

[0130] Where ΔP d ∈R n is the network loss allocated to the sink, ΔP n ∈R n is the total input loss of the node, including the loss transmitted from the upstream node. ns ∈R n is the node loss, whose elements are defined as:

[0131]

[0132] If consumption-based loss allocation is adopted, traditional power flow tracking simply tells users how much network loss they are responsible for. However, to determine the carbon emissions corresponding to the user-side allocated network loss, carbon flow tracking should further clarify which generation sources provided additional energy to offset the user-side allocated losses. This can be accomplished by splitting the energy distribution according to different sources.

[0133] Let ΔP sk,ij Indicates the effect of source k on ΔP ij The contribution of ΔP ij It can be divided into several parts according to the source:

[0134]

[0135] Among them, a jk (-1) It's A -1 The jth row and kth column element of . sk,ij The further explanation of is as follows. In the lossy network, (5) is modified to P n '=A -1 P s .P n '∈R n is the total node flow in the equivalent lossless network. nj 's contributions are as follows:

[0136]

[0137] According to the proportional sharing rule, the contribution of source k to the output branch of node j is the same as (10). Therefore, the contribution of source k to ΔP ij The contribution of satisfies (9). It can be rewritten as follows:

[0138]

[0139] Formula (7) and Formula (11) can be rearranged into the following form:

[0140] ΔP ns =MΔP b (12)

[0141] ΔP b =NP s (13)

[0142] Where M∈R n×b ,N∈R n×b The elements of are defined as follows:

[0143]

[0144] Putting equations (6), (12), and (13) together, we can get the contribution of the source to the allocation loss in the sink as follows:

[0145] ΔP d =LP s ,L=BA -1 MN. (16)

[0146] L∈R n×n The columns correspond to the contribution of the corresponding source to the network loss distributed by all sinks. By adding up each column of L, we can get the total contribution rate of the corresponding source:

[0147] ΔP s =diag{L T e}P s (17)

[0148] Among them, L T is the transpose of L, and e is a column vector with each element equal to 1. Therefore, the actual input to the sink in the lossy network is expressed as follows:

[0149] P d =HP s , H=BA -1 -L. (18)

[0150] According to equations (16) and (18), the final contribution of the source to the sink is expressed as follows:

[0151] P d ′=FP s , F=H+L=BA -1 . (19)

[0152] Step 3: Calculate regional carbon accounts based on carbon source emission rates. For regional carbon accounting, calculate the carbon emissions of each region using the emission rate of each region.

[0153] P s ,P d ∈R n It represents the output of sources and the input of sinks, i.e., the regional power output of suppliers and the regional power input of consumers.

[0154]

[0155] Among them, S s ,S d Represents the collection of carbon sources and carbon sinks respectively. ai ,P li Represent the local power generation and local power consumption of the region respectively. cij It is the direct supply from region i to region j and is negative when the direction is opposite.

[0156] P s ,P d ∈R n Participating in carbon flow tracking has the following relationships:

[0157] P d =FP S . (twenty one)

[0158] Where F∈R n×n is a constant matrix that can be defined as the source-to-sink contribution matrix.

[0159] Let C s ,C d ∈R n Represent the output of carbon source and the input of carbon sink respectively. They can be converted into carbon emission amount according to regional emission rate. The regional emission rate of region i is represented by σ i To express, so C si =σ i P si Therefore, the results of carbon flow tracking are as follows:

[0160] C d =FC s . (twenty two)

[0161] Taking into account local consumption and direct supply, the final carbon emission account for each region is in the following form:

[0162]

[0163] Among them C ai The calculation method of C si Same, but C cij It is calculated based on the emission rates of specific generators that directly supply electricity to other areas.

[0164] Step 4: Assess regional carbon emission intensity: Assess the carbon emission intensity of different regions based on their power supply structures.

[0165] Apply the flow tracing method to carbon intensity assessment. Let P s , P d Represent the output power of carbon source and the input power of carbon sink respectively. s , P d ∈R n The elements are:

[0166]

[0167] Among them, S s , S d is the set of generator buses and load buses in the simplified network. a , P l ∈Rn are the vectors generated and consumed by the node respectively.

[0168] δ∈R n Represents the carbon intensity of the electricity supplied by each bus line. represents the emission rate of the generator on bus i, where ε i is the number of generators on the bus. The carbon intensity at the bus level is obtained as:

[0169]

[0170] Among them, P gij represents the output of generator j on bus i, and its emission rate is δ gij . F i is the i-th row of the matrix F. diag{δ} is δ∈R n The diagonal matrix of .

[0171] A device for a consumption-based carbon emission accounting method based on carbon flow tracking technology, comprising:

[0172] The carbon source and carbon sink determination module is used to simplify each region into a pure carbon source or a pure carbon sink. The carbon flow passes through the directed branch from the carbon source to the final carbon sink through the intermediate nodes to obtain the input and output relationship of each node;

[0173] A module for determining the contribution of a carbon source to a pure carbon sink, used to determine the contribution of a pure carbon source to a pure carbon sink;

[0174] The carbon emissions module is used for regional carbon accounting, using the emission rate of each region to calculate the carbon emissions of each region; the carbon emission intensity assessment module is used to assess the carbon emission intensity of different regions based on carbon source output, carbon sink input and carbon emission rate.

[0175] In the carbon source and carbon sink determination module, the input and output relationship of each node is obtained as follows: the emission rate of power supply is calculated based on the energy structure of the power output area. If there is cross-regional direct power supply, it is calculated based on the emission rate of the power supply generator. In the carbon flow tracking process, cross-regional direct supply is eliminated. When the elimination amount is greater than the original output of the carbon source or the original input of the carbon sink, for the user-level carbon intensity assessment, the node represents the bus. It is assumed that the generator preferentially supplies power to the load on the same bus and is merged on each bus to form a simplified network. The output of the carbon source is the carbon emissions related to the net input power of the bus, and the input of the carbon sink is the carbon emissions related to the net output power of the bus. The power supply emission rate is calculated based on the power supply generator.

[0176] Given a network with n nodes, b branches, s sources and d sinks, the output of the source and the input of the sink are P s ,P d ∈R n, process tracing identifies the following relationships:

[0177] f(P s ):P s →P d . (1)

[0178] According to the proportional sharing rule, the input and output calculation formula of each node is linear, and the input and output calculation formula of each node is expressed as:

[0179] P d =FP s

[0180] Where F∈R n×n is a constant matrix defined as the source-to-sink contribution matrix.

[0181] In the pure carbon source to pure carbon sink contribution determination module, the carbon flow tracking method is used to determine the contribution of pure carbon source to pure carbon sink. The expression is:

[0182] P d '=FP s , F=H+L=BA -1 (19)

[0183] L∈R n×n The columns correspond to the contribution of the corresponding source to the network loss allocated to all sinks, P s ∈R n represents the output of the source,

[0184] The elements of matrix A are defined as:

[0185]

[0186] Among them, i - is a set of nodes, j∈i - Indicates P ji is the input flow of node i, if ji is the output branch of node i, then P ji is a negative value;

[0187] The elements of matrix B are defined as:

[0188]

[0189] In the carbon emissions module, the method for calculating the carbon emissions of each region is as follows: s , P d ∈R n represents the output of the source and the input of the sink, i.e., the regional power output of the supplier and the regional power input of the consumer,

[0190]

[0191] Among them, S s , S d Represents the collection of carbon sources and carbon sinks, P ai ,P li Represent the local power generation and local power consumption of the region, P cij is the direct supply from region i to region j, and is negative when the direction is opposite.

[0192] P s ,P d ∈R n Participating in carbon flow tracking has the following relationships:

[0193] P d =FP S . (twenty one)

[0194] Where F∈R n×n is a constant matrix;

[0195] C s ,C d ∈R n They represent the output of carbon sources and the input of carbon sinks respectively, and are converted into carbon emissions according to the regional emission rate. The regional emission rate of region i is represented by σ i To express, C si =σ i P si , the results of carbon flow tracking are as follows:

[0196] C d =FC s . (twenty two)

[0197] The final carbon emissions account for each region is in the following form:

[0198]

[0199] Among them C ai The calculation method of C si Same, but C cij It is calculated based on the emission rates of specific generators that directly supply electricity to other areas.

[0200] In the carbon emission intensity assessment module, the method for assessing the carbon emission intensity of different regions is as follows: Apply the flow tracking method to the carbon intensity assessment,

[0201] P s , P d Represent the output power of carbon source and the input power of carbon sink, P s , P d ∈R n The elements are:

[0202]

[0203] Among them, S s , S d is the set of generator bus and load bus in the simplified network, P a , P l ∈R n are the vectors generated and consumed by the node,

[0204] δ∈R n represents the carbon intensity of power supply for each bus line, represents the emission rate of the generator on bus i, where ε i is the number of generators on the bus, thus obtaining the carbon intensity at the bus level:

[0205]

[0206] Among them, P gij represents the output of generator j on bus i, and its emission rate is δ gij , F i is the i-th row of matrix F, diag{δ} is δ∈R n The diagonal matrix of .

[0207] Experimental verification:

[0208] Six regions in China's power system are used as examples. The proposed method is tested on this six-region system to demonstrate its effectiveness. Local production, fuel consumption, and total final electricity consumption are sourced from the China Energy Statistical Yearbook. Interregional exchange data are sourced from the Electric Power Industry Statistical Compendium, with transmission losses calculated as 2% of the transmitted electricity. Carbon emissions are calculated according to the IPCC Guidelines for National Greenhouse Gas Inventories. Basic data are summarized in Table 1.

[0209] Table 1 Basic data of China's six major regions

[0210]

[0211] The electricity exchange between the six regions is processed according to step 1. The simplified regional carbon flow tracing network is as follows: Figure 2 The direct supply from North China to East China is shown in Figure 2. The dotted arrows represent the direct supply from North China to East China. By removing this from the carbon flow tracking process, the North China node shifts from a carbon source to a carbon sink.

[0212] The carbon emissions of local electricity consumption and direct power supply were calculated according to formula (23), and the final calculation results of carbon emissions in each region are shown in Table 2, which gives the emission rate of direct power supply as 0.84 kg / kWh.

[0213] Table 2 Carbon accounting results in different regions

[0214]

[0215] As shown in Tables 1 and 2, the differences between the local carbon emissions and the results of the proposed method are significant. Figure 3 As shown, the carbon account of Central China, a major electricity exporting region, decreased by 9%, while import-dependent regions such as East China and South China increased by 7% and 4%, respectively. Consequently, regions dependent on electricity imports shouldered a larger share of carbon obligations, alleviating pressure on electricity exporting regions. By internalizing carbon obligations in electricity importing regions, these regions are encouraged to support carbon emission reductions in electricity supplying regions. This may contribute to interregional carbon reduction cooperation and the achievement of national carbon reduction targets.

[0216] The present invention is described by way of example, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be within the scope of the present invention.

Claims

1. A consumption-based carbon emission accounting method based on carbon flow tracking technology, characterized in that: The following steps are involved: Determine the carbon source and carbon sink, simplify each area into a pure carbon source and a pure carbon sink, and the carbon flow passes through the directed branch from the carbon source to the final carbon sink through the intermediate nodes to obtain the input and output relationship of each node; Use carbon flow tracking methods to determine the contribution of pure carbon sources to pure carbon sinks; Based on the contribution of pure carbon sources to pure carbon sinks, regional carbon accounts are calculated according to the carbon source emission rates. For regional carbon accounting, the carbon emissions of each region are calculated using the emission rates of each region. The carbon emission intensity of different regions is evaluated based on carbon source output, carbon sink input and carbon emission rate.

2. According to claim 1, a consumption-based carbon emission accounting method based on carbon flow tracking technology is characterized by: The method to obtain the input and output relationship of each node is as follows: the emission rate of power supply is calculated according to the energy structure of the power output area. If there is cross-regional direct power supply, it is calculated according to the emission rate of the power supply generator. In the process of carbon flow tracking, cross-regional direct supply is eliminated. When the elimination amount is greater than the original output of the carbon source or the original input of the carbon sink, for the user-level carbon intensity assessment, the node represents the bus. It is assumed that the generator preferentially supplies power to the load on the same bus and is merged on each bus to form a simplified network. The output of the carbon source is the carbon emissions related to the net input power of the bus, and the input of the carbon sink is the carbon emissions related to the net output power of the bus. The power supply emission rate is calculated based on the power supply generator. Given a network with n nodes, b branches, s sources and d sinks, the output of the source and the input of the sink are P s ,P d ∈R n , process tracing determines the following relationships: f(P s ):P s →P d . (1) According to the proportional sharing rule, the input and output calculation formula of each node is linear, and the input and output calculation formula of each node is expressed as: P d =FP s Where F∈R n×n is a constant matrix defined as the source to sink contribution matrix.

3. The method for calculating consumption-based carbon emissions based on carbon flow tracking technology according to claim 1 is characterized in that: The expression for determining the contribution of pure carbon source to pure carbon sink using carbon flow tracking method is: P d '=FP s ,F=H+L=BA -1 (19) L∈R n×n The columns correspond to the contribution of the corresponding source to the network loss allocated to all sinks, P s ∈R n Representing the output of the source, the elements of the matrix A are defined as: Among them, i - is a set of nodes, j∈i - Indicates P ji is the input flow of node i, if ji is the output branch of node i, then P ji is a negative value; The elements of matrix B are defined as:

4. The method for calculating consumption-based carbon emissions based on carbon flow tracking technology according to claim 1 is characterized in that: The method for calculating carbon emissions in each region is as follows: s , P d ∈R n represents the output of sources and the input of sinks, i.e., the regional power output of suppliers and the regional power input of consumers, Among them, S s , S d Represents the collection of carbon sources and carbon sinks, P ai ,P li Represent the local power generation and local power consumption of the region, P cij is the direct supply from region i to region j. It is negative when the direction is opposite. P s ,P d ∈R n Participating in carbon flow tracking has the following relationships: P d =FP S . (21) Where F∈R n×n is a constant matrix; C s ,C d ∈R n They represent the output of carbon source and the input of carbon sink respectively, and are converted into carbon emission quantity according to the regional emission rate. The regional emission rate of region i is represented by σ i To indicate that C si =σ i P si , the results of carbon flow tracking are as follows: C d =FC s . (22) The final carbon emission accounts for each region are in the following form: Among them C ai The calculation method of C si Same, but C cij It is calculated based on the emission rates of specific generators that directly supply electricity to other areas.

5. The method for calculating consumption-based carbon emissions based on carbon flow tracking technology according to claim 1 is characterized in that: The method for assessing the carbon emission intensity of different regions is as follows: Apply the flow tracking method to carbon intensity assessment, P s , P d Represent the output power of the carbon source and the input power of the carbon sink, P s , P d ∈R n The elements are: Among them, S s , S d is the set of generator buses and load buses in the simplified network, P a , P l ∈R n are the vectors generated and consumed by the node, δ∈R n Represents the carbon intensity of each bus line supply, Δ gi ∈R εi represents the emission rate of the generator on bus i, where ε i is the number of generators on the bus, thus obtaining the carbon intensity at the bus level: Among them, P gij represents the output of generator j on bus i, and its emission rate is δ gij , F i is the i-th row of the matrix F, and diag{δ} is δ∈R n The diagonal matrix of .

6. A device for a consumption-based carbon emission accounting method based on carbon flow tracking technology, characterized in that: include: The carbon source and carbon sink determination module is used to simplify each region into a pure carbon source or a pure carbon sink. The carbon flow passes through the directed branch from the carbon source to the final carbon sink through the intermediate nodes to obtain the input and output relationship of each node; A module for determining the contribution of a carbon source to a pure carbon sink, used to determine the contribution of a pure carbon source to a pure carbon sink; The carbon emission module is used for regional carbon accounting, using the emission rate of each region to calculate the carbon emissions of each region; the carbon emission intensity assessment module is used to assess the carbon emission intensity of different regions based on carbon source output, carbon sink input and carbon emission rate.

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