Enterprise power indirect carbon emission accounting method and power utilization strategy optimization method and system

Abstract

The invention provides an enterprise power indirect carbon emission accounting method and a power utilization strategy optimization method and system.The method comprises the steps that firstly, a regional power system transaction flow trend is obtained based on green power transaction information, and then the power utilization strategy is optimized according to the actual trend and the obtained regional power system transaction flow trend; the method comprises the following steps: calculating the carbon potential of a non-transaction flow part of a power grid node n accessed by an enterprise, calculating the indirect power carbon emission of the enterprise in combination with the carbon potential of the non-transaction flow part of the power grid node n, power consumption information of the enterprise and green power and green certificate information, and finally calculating the indirect power carbon emission of the enterprise by considering the power consumption cost of the enterprise and the calculated indirect power carbon emission. And constructing an enterprise green power utilization strategy optimization model, and solving to obtain an enterprise optimal power utilization strategy. According to the invention, accurate accounting of enterprise power indirect carbon emission can be realized, and a green power utilization strategy is provided for enterprises.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power, and particularly relates to a method for calculating indirect carbon emissions of enterprise electric power, a method for optimizing power consumption strategies, and a system therefor. Background Art

[0002] With the increasingly serious problem of climate change, reducing carbon emissions and pursuing sustainable development have become the consensus of the whole society. As the core participants in social and economic activities, enterprises play a crucial role in the task of reducing carbon emissions. Along with the rapid development of electrification, the electricity demand in industries such as industry, construction, and transportation has increased significantly, and the proportion of indirect emissions brought by enterprise electricity consumption has also gradually increased. The accurate calculation of indirect carbon emissions from electricity has become the basis and prerequisite for supporting the refined management and control of carbon emissions by enterprises, and supports the green and high-quality development of enterprises.

[0003] The existing methods for calculating indirect carbon emissions of enterprise electricity adopt a single and fixed electricity carbon emission factor, which cannot reflect the influence of the time series difference of clean energy power generation and the time series volatility of power supply and demand on the electricity carbon emission factor, and cannot meet the monitoring and management requirements of emission control enterprises for their own carbon emissions. At the same time, these calculation methods do not consider the impact of green power trading on the electricity carbon emission factor. After considering the environmental attributes of green power / green certificates, continuing to use the original average emission factor of the regional power grid will lead to double counting of the environmental attributes of renewable energy power, which is not conducive to stimulating the enthusiasm of enterprises for green power consumption. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for calculating indirect carbon emissions of enterprise electricity, a method for optimizing power consumption strategies, and a system therefor in view of the above problems existing in the prior art.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] In the first aspect, the present invention provides a method for calculating indirect carbon emissions of enterprise electricity, including:

[0007] A1. Obtaining the power flow of the regional power system transaction flow based on green power trading information;

[0008] A2. Calculating the carbon potential of the non-trading flow part of the grid node n accessed by the enterprise according to the actual power flow and the power flow of the regional power system transaction flow obtained in step A1;

[0009] A3. Combining the carbon potential of the non-trading flow part of the grid node n, the electricity consumption information of the enterprise, and the green power / green certificate information to calculate and obtain the indirect carbon emissions of the enterprise electricity.

[0010] In A2, the carbon potential of the non-trading flow part of the grid node n accessed by the enterprise is calculated according to the following formula:

[0011] εn,t = [P t NA - (P E,t,l ) T - 1 (P G,t ) T ε G

[0012] P E,t,l = P A,t,l - P F,t,l

[0013] In the above formula, ε n,t is the carbon potential of grid node n at time t, P t NA , P G,t , ε G are the active power flux matrix of nodes, the output matrix of non-trading units, and the vector of carbon emission factors of non-trading unit power generation under the non-trading flow distribution at time t respectively. P A,t,l is the actual power flow of line l at time t, P F,t,l , P E,t,l are the trading flow power and non-trading flow power of branch l at time t respectively.

[0014] In the above-mentioned A1, the trading flow power of the regional power system is calculated according to the following formula:

[0015]

[0016] In the above formula, P F,t,l is the trading flow power of branch l of the regional power system at time t, T PTDF is the power transfer distribution factor matrix of the regional power system, are the injection power flows of the green power contract portfolio x and the green certificate portfolio y at grid node n at time t respectively, is the part of the network loss of branch l allocated to green power trading at time t, Ψ is the conversion function that converts the trading flow branch power flow column vector into a trading flow branch power flow distribution matrix, is the lossless trading power flow of green power trading (x + y) on branch l at time t, P A,t,l , are the actual power flow and actual network loss of branch l at time t respectively.

[0017] In the above-mentioned A3, the indirect carbon emissions of enterprise electricity are calculated according to the following formula:

[0018] E cal,t = (Q us,t - Q gr,t - Q se,t - 1000N gr )ε n,t

[0019] In the above formula, E cal,t is the indirect carbon emissions of enterprise electricity in period t, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading volume, and self-generated new energy electricity consumption of the enterprise in period t respectively, N gr is the number of green certificates, and ε n,t is the carbon potential of grid node n in period t.

[0020] Second, the present invention proposes an optimization method for enterprise electricity consumption strategies, including:

[0021] B1. Using the aforementioned method to calculate the indirect carbon emissions of enterprise electricity;

[0022] B2. Constructing an optimization model for enterprise green electricity consumption strategies considering enterprise electricity consumption costs and indirect carbon emissions of electricity;

[0023] B3. Solving the optimization model for enterprise green electricity consumption strategies to obtain the optimal electricity consumption strategy of the enterprise.

[0024] The objective function of the optimization model for enterprise green electricity consumption strategies includes:

[0025]

[0026] W 1 =(Q us,t -Q gr,t -Q se,t -1000N gr )γ 0

[0027] W 2 =Q gr,t γ 1 +Q se,t γ 2 +N gr γ 3

[0028] W 3 =(E fp -E cal,t )γ 4

[0029] In the above formula, F t is the enterprise green electricity consumption index in period t, κ is the weight coefficient representing the balance relationship between low carbon and economy, W 1 , W 2 , W 3 are the non-green electricity consumption cost, green electricity consumption cost, and carbon quota market income of the enterprise respectively, Q us,t , Q gr,t , Qse,t They are the electricity consumption, green power trading electricity volume, and self-generated electricity volume from new energy of the enterprise during the t period, respectively, E cal,t is the indirect carbon emissions of the enterprise's electricity during the t period, N gr is the number of green certificates, γ 0 , γ 1 , γ 2 , γ 3 , γ 4 They are the ordinary electricity price, the electricity price of the green power trading agreement contract, the cost per kilowatt-hour of self-generated electricity from new energy, the price of green certificates, and the price of carbon quotas, respectively, E fp is the enterprise's carbon quota;

[0030] The constraints include:

[0031] W 1 +W 2 -W 3 ≤W pre

[0032] E cal,pre ≤E cal,t

[0033] In the above formula, W pre is the enterprise's electricity cost budget, E cal,pre is the carbon emission target set by the enterprise.

[0034] Thirdly, the present invention proposes an enterprise indirect carbon emissions accounting system for electricity, including a transaction flow power flow calculation unit, a carbon potential calculation unit, and an indirect carbon emissions accounting unit;

[0035] The transaction flow power flow calculation module is used to obtain the transaction flow power flow of the regional power system based on the green power trading information;

[0036] The carbon potential calculation unit is used to calculate the carbon potential of the non-transaction flow part of the grid node n accessed by the enterprise according to the actual power flow and the obtained transaction flow power flow of the regional power system;

[0037] The indirect carbon emissions accounting unit is used to calculate and obtain the enterprise's indirect carbon emissions of electricity by combining the carbon potential of the non-transaction flow part of the grid node n, the enterprise's electricity consumption information, and the green power and green certificate information.

[0038] The transaction flow power flow of the regional power system is calculated according to the following formula:

[0039]

[0040]

[0041] In the above formula, P F ,t,l is the transaction flow power flow of the regional power system branch l during the t period, TPTDF is the power transfer distribution factor matrix of the regional power system, are the injection power flows of the green power contract portfolio x and the green certificate portfolio y at the grid node n in period t, is the part of the line loss on branch l in period t allocated to the green power transaction. Ψ is the conversion function that converts the branch power flow column vector of the transaction flow into the branch power flow distribution matrix, is the lossless transaction power flow of the green power transaction (x + y) on branch l in period t, P A,t,l 、 are the actual power flow and actual line loss of branch l in period t respectively;

[0042] The carbon potential of the non - transaction - flow part of the grid node n connected by the enterprise is calculated according to the following formula:

[0043] ε n,t =[P t NA -(P E,t,l ) T - 1 (P G,t ) T ε G

[0044] P E,t,l =P A,t,l -P F,t,l

[0045] In the above formula, ε n,t is the carbon potential of the grid node n in period t, P t NA 、P G,t 、ε G are the node active power flux matrix, non - transaction unit output matrix, and non - transaction unit power generation carbon emission factor vector under the non - transaction - flow distribution in period t respectively. P A,t,l is the actual power flow of line l in period t, P F,t,l 、P E,t,l are the transaction - flow power flow and non - transaction - flow power flow of branch l in period t respectively;

[0046] The indirect carbon emissions of the enterprise's electricity are calculated according to the following formula:

[0047] E cal,t =(Q us,t -Q gr,t -Q se,t -1000N gr )ε n,t

[0048] In the above formula, E cal,t is the indirect carbon emissions of the enterprise's electricity in period t, Q us,t 、Qgr,t , Q se,t are the electricity consumption, green power trading electricity volume, and self-generated electricity volume from new energy of the enterprise during the t period, respectively. N gr is the number of green certificates, and ε n,t is the carbon potential of grid node n during the t period.

[0049] Fourthly, the present invention proposes an enterprise electricity consumption strategy optimization system, including an enterprise indirect carbon emissions accounting module for electricity, an optimization model construction module, and an optimization model solution module;

[0050] The enterprise indirect carbon emissions accounting module for electricity is used to calculate the enterprise indirect carbon emissions by using the foregoing method;

[0051] The optimization model construction module is used to construct an enterprise green electricity consumption strategy optimization model considering the enterprise electricity consumption cost and the indirect carbon emissions of electricity;

[0052] The optimization model solution module is used to solve the enterprise green electricity consumption strategy optimization model to obtain the optimal electricity consumption strategy of the enterprise.

[0053] The objective function of the enterprise green electricity consumption strategy optimization model includes:

[0054]

[0055] W 1 =(Q us,t -Q gr,t -Q se,t -1000N gr )γ 0

[0056] W 2 =Q gr,t γ 1 +Q se,t γ 2 +N gr γ 3

[0057] W 3 =(E fp -E cal,t )γ 4

[0058] In the above formula, F t is the enterprise green electricity consumption index during the t period, κ is the weight coefficient representing the balance relationship between low carbon and economy, W 1 , W 2 , W 3 are the non-green electricity consumption cost, green electricity consumption cost, and carbon quota market income of the enterprise, respectively. Q us,t , Q gr,t , Qse,t are the electricity consumption, green power trading electricity volume, and self-generated electricity volume from new energy of the enterprise during the t period, respectively, and E cal,t is the indirect carbon emissions of the enterprise's electricity during the t period, and N gr is the number of green certificates, and γ 0 , γ 1 , γ 2 , γ 3 , γ 4 are the ordinary electricity price, the electricity price of the green power trading agreement contract, the cost per unit of self-generated electricity from new energy, the price of green certificates, and the price of carbon quotas, respectively, and E fp is the carbon quota of the enterprise;

[0059] The constraints include:

[0060] W 1 +W 2 -W 3 ≤W pre

[0061] E cal,pre ≤E cal,t

[0062] In the above formula, W pre is the electricity cost budget of the enterprise, and E cal,pre is the carbon emission target set by the enterprise.

[0063] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0064] 1. A method for calculating the indirect carbon emissions of an enterprise's electricity first obtains the power flow of the regional power system trading flow based on the green power trading information, then calculates the carbon potential of the non-trading flow part of the grid node n accessed by the enterprise according to the actual power flow and the obtained power flow of the regional power system trading flow, and then combines the carbon potential of the non-trading flow part of the grid node n, the electricity consumption information of the enterprise, and the green power and green certificate information to calculate and obtain the indirect carbon emissions of the enterprise's electricity. This method takes into account green power trading and actual network losses, and splits the green power trading part based on the power transfer distribution factor matrix, which can effectively solve the problem of double counting of green attributes faced by emission control enterprises in the calculation of indirect carbon emissions of electricity, and achieve accurate calculation of the indirect carbon emissions of the enterprise's electricity.

[0065] 2. A method for optimizing the electricity consumption strategy of an enterprise considers the electricity consumption cost of the enterprise and the calculated indirect carbon emissions of electricity, constructs an optimization model for the enterprise's green electricity consumption strategy, and then solves to obtain the optimal electricity consumption strategy of the enterprise. This method provides a green electricity consumption strategy for the enterprise, helps the enterprise achieve green electricity consumption at the lowest cost, promotes green power consumption, and supports the green and low-carbon transformation of the enterprise. Description of the Drawings

[0066] Figure 1It is a flowchart of the method according to the present invention.

[0067] Figure 2 It is a structural diagram of the system described in Embodiment 3.

[0068] Figure 3 It is a structural diagram of the system described in Embodiment 4. Detailed implementation manners

[0069] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0070] Embodiment 1:

[0071] Taking an enterprise as an example, an indirect carbon emission accounting method for enterprise electricity of the present invention is implemented. As Figure 1 shown, the specific steps are as follows:

[0072] 1. Obtain the green power trading information in the market, and obtain the injection power flow of the green power contract portfolio x and the green certificate portfolio y at the grid node n accessed by the enterprise in the t period

[0073] 2. Use the PTDF matrix conversion to obtain the lossless trading power flow distribution matrix:

[0074]

[0075] In the above formula, is the lossless trading power flow distribution matrix in the t period, Ψ is the conversion function for converting the trading flow branch power flow column vector into the trading flow branch power flow distribution matrix, is the power flow column vector of branch l in the t period under green power trading, and T PTDF is the power transfer distribution factor matrix of the regional power system.

[0076] 3. Allocate the network loss on a certain branch according to the ratio of the lossless trading power flow corresponding to the green power trading to the physical power flow on the branch, and thus obtain the part of the network loss on line l in the t period allocated to the green power trading as:

[0077]

[0078] In the above formula, is the lossless trading power flow of the green power trading (x + y) on branch l in the t period, and P A ,t,l, are respectively the actual power flow and actual network loss of branch l in the regional power system in the t period.

[0079] 4. Superimpose the lossless transaction power flow and the transaction network loss part, and recalculate using the PTDF matrix to obtain the green power transaction flow power P with complete information, which can be expressed as: F ,t,l

[0080]

[0081] 5. Split the actual power flow P of the regional power system A,t,l into the transaction flow part P F,t,l and the non-transaction flow part P E,t,l , and we have:

[0082] P E,t,l = P A,t,l - P F,t,l .

[0083] 6. Based on the non-transaction flow part, calculate the carbon potential ε of the grid node n accessed by the enterprise under green power transactions n,t , and we have:

[0084] ε n,t = [P t NA - (P E,t,l ) T - 1 (P G,t ) T ε G

[0085] In the above formula, P t NA , P G,t , and ε G are the nodal active power flux matrix, non-transaction unit output matrix, and non-transaction unit power generation carbon emission factor vector under the non-transaction flow distribution at time t, respectively.

[0086] In this embodiment, the typical non-transaction unit power generation carbon emission factors are shown in Table 1:

[0087] Table 1 Typical non-transaction unit power generation carbon emission factors

[0088]

[0089] The calculated carbon potential of grid node n is 0.3672 kgCO 2 / kWh.

[0090] 7. Combine the carbon potential of the non-transaction flow part of grid node n, the enterprise's electricity consumption information, and the green power and green certificate information to calculate the enterprise's indirect carbon emissions from electricity:

[0091] E cal,t = (Q us,t - Q gr,t-Q se,t -1000N gr )ε n,t

[0092] In the above formula, E cal,t is the indirect carbon emissions of enterprise electricity in period t, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading volume, and self-generated new energy electricity volume of the enterprise in period t respectively, N gr is the number of green certificates, and ε n,t is the carbon potential of grid node n in period t.

[0093] In this embodiment, Q us,t , Q gr,t , Q se,t are 3200 MWH, 200 MWH, and 350 MWH respectively, N gr is 120, and the calculated annual indirect carbon emissions of electricity are 929 tons of carbon dioxide.

[0094] Embodiment 2:

[0095] An enterprise electricity consumption strategy optimization method, as Figure 1 shown, the specific steps are as follows:

[0096] 1. Calculate the indirect carbon emissions of enterprise electricity according to the method described in Embodiment 1.

[0097] 2. Construct an enterprise green electricity consumption strategy optimization model considering enterprise electricity consumption cost and indirect carbon emissions of electricity. The objective function of this model includes:

[0098]

[0099] W 1 =(Q us,t -Q gr,t -Q se,t -1000N gr )γ 0

[0100] W 2 =Q gr,t γ 1 +Q se,t γ 2 +N gr γ 3

[0101] W 3 =(E fp -E cal,t )γ 4

[0102] In the above formula, Ft is the enterprise green electricity consumption index in the t period, κ is the weight coefficient representing the balance relationship between low carbon and economy, W 1 、W 2 、W 3 are the non-green electricity consumption cost, green electricity consumption cost, and carbon quota market revenue of the enterprise respectively, Q us,t 、Q gr,t 、Q se,t are the electricity consumption, green electricity trading volume, and self-generated new energy electricity consumption of the enterprise in the t period respectively, E cal,t is the indirect carbon emissions of enterprise electricity in the t period, N gr is the number of green certificates, γ 0 、γ 1 、γ 2 、γ 3 、γ 4 are the ordinary electricity price, green electricity trading agreement contract price, self-generated new energy electricity cost per degree, green certificate price, and carbon quota price respectively, E fp is the enterprise carbon quota;

[0103] The constraint conditions include:

[0104] W 1 +W 2 -W 3 ≤W pre

[0105] E cal,pre ≤E cal,t

[0106] In the above formula, W pre is the enterprise electricity cost budget, E cal,pre is the enterprise-set carbon emission target.

[0107] 3. Solve the enterprise green electricity consumption strategy optimization model to obtain the optimal electricity consumption strategy of the enterprise.

[0108] Example 3:

[0109] An enterprise indirect carbon emissions accounting system for electricity, as Figure 2 shown, includes a transaction flow power flow calculation module, a carbon potential calculation unit, and an indirect carbon emissions accounting unit.

[0110] The transaction flow power flow calculation unit is used to calculate the transaction flow power flow of the regional power system based on the green power trading information according to the following formula:

[0111]

[0112] In the above formula, P F ,t,l is the transaction flow power flow of branch l of the regional power system in the t period, T PTDFis the power transfer distribution factor matrix of the regional power system, are the injection power flows of the green power contract portfolio x and the green certificate portfolio y at the grid node n during the t period, respectively, is the part of the line loss on the branch l during the t period allocated to the green power transaction, and Ψ is the conversion function that converts the transaction flow branch power flow column vector into a transaction flow branch power flow distribution matrix, is the lossless transaction power flow of the green power transaction (x + y) on the branch l during the t period, P A,t,l 、 are the actual power flow and the actual line loss of the branch l during the t period, respectively.

[0113] The carbon potential calculation unit is used to calculate the carbon potential of the non-transaction flow part of the grid node n accessed by the enterprise according to the actual power flow and the obtained transaction flow power flow of the regional power system, according to the following formula:

[0114] The carbon potential of the non-transaction flow part of the grid node n accessed by the enterprise is calculated according to the following formula:

[0115] ε n,t =[P t NA -(P E,t,l ) T -1 (P G,t ) T ε G

[0116] P E,t,l =P A,t,l -P F,t,l

[0117] In the above formula, ε n,t is the carbon potential of the grid node n during the t period, P t NA 、P G,t 、ε G are the node active power flux matrix, the non-transaction unit output matrix, and the non-transaction unit power generation carbon emission factor vector under the non-transaction flow distribution during the t period, respectively, P A,t,l is the actual power flow of the line l during the t period, P F,t,l 、P E,t,l are the transaction flow power flow and the non-transaction flow power flow of the branch l during the t period, respectively.

[0118] The indirect carbon emission accounting unit is used to calculate the indirect carbon emissions of the enterprise's electricity by combining the carbon potential of the non-transaction flow part of the grid node n, the enterprise's electricity consumption information, and the green power and green certificate information, according to the following formula:

[0119] E cal,t =(Q us,t -Q gr,t -Q​se,t -1000N gr )ε n,t

[0120] In the above formula, E cal,t is the indirect carbon emissions of enterprise electricity in period t, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading volume, and self-generated new energy electricity volume of the enterprise in period t respectively, N gr is the number of green certificates, and ε n,t is the carbon potential of grid node n in period t.

[0121] Example 4:

[0122] An enterprise electricity consumption strategy optimization system, as Figure 3 shown, includes an enterprise indirect carbon emissions accounting module, an optimization model construction module, and an optimization model solving module.

[0123] The enterprise indirect carbon emissions accounting module is used to calculate the enterprise indirect carbon emissions by using the method described in Example 1.

[0124] The optimization model construction module is used to construct an enterprise green electricity consumption strategy optimization model considering the enterprise electricity consumption cost and indirect carbon emissions of electricity. The objective function of this model includes:

[0125]

[0126] W 1 =(Q us,t -Q gr,t -Q se,t -1000N gr )γ 0

[0127] W 2 =Q gr,t γ 1 +Q se,t γ 2 +N gr γ 3

[0128] W 3 =(E fp -E cal,t )γ 4

[0129] In the above formula, F t is the enterprise green electricity consumption index in period t, κ is the weight coefficient representing the balance relationship between low carbon and economy, W 1 , W 2 , W 3They are the non-green electricity cost, green electricity cost, and carbon quota market revenue of the enterprise, respectively, Q us,t 、Q gr,t 、Q se,t They are the electricity consumption, green electricity trading volume, and self-generated electricity consumption from new energy of the enterprise during the t period, respectively, E cal,t is the indirect carbon emissions of the enterprise's electricity during the t period, N gr is the number of green certificates, γ 0 、γ 1 、γ 2 、γ 3 、γ 4 They are the ordinary electricity price, the contract price of the green electricity trading agreement, the cost per unit of self-generated electricity from new energy, the price of green certificates, and the price of carbon quotas, respectively, E fp is the carbon quota of the enterprise;

[0130] The constraint conditions include:

[0131] W 1 +W 2 -W 3 ≤W pre

[0132] E cal,pre ≤E cal,t

[0133] In the above formula, W pre is the electricity cost budget of the enterprise, and E cal,pre is the carbon emission target set by the enterprise.

[0134] The optimization model solving module is used to solve the enterprise's green electricity strategy optimization model to obtain the enterprise's optimal electricity strategy.

Claims

1. A method for calculating indirect carbon emissions from corporate electricity, characterized in that: The method comprises: A1. Based on the green power trading information, the trading flow of the regional power system is obtained; A2. Calculate the carbon potential of the non-transaction flow part of the grid node n to which the enterprise is connected based on the actual power flow and the regional power system transaction flow obtained in step A1; A3. Combining the carbon potential of the non-trading flow of grid node n, the enterprise's electricity consumption information and green electricity and green certificate information, the enterprise's indirect carbon emissions from electricity are calculated.

2. According to claim 1, a method for calculating indirect carbon emissions from corporate electricity is characterized in that: In A2, the carbon potential of the non-trading flow part of the grid node n connected to the enterprise is calculated according to the following formula: e n,t =[P t NA -(P E,t,l ) T ] -1 (P G,t ) T e G P E,t,l =P A,t,l -P F,t,l In the above formula, ε n,t is the carbon potential of grid node n during period t, P t NA , P G,t , ε G are the node active flux matrix, non-trading unit output matrix, and non-trading unit power generation carbon emission factor vector under the non-trading flow distribution in period t, respectively. A,t,l is the actual power flow of line l during period t, P F,t,l , P E,t,l They are the transaction flow and non-transaction flow of branch l in period t respectively.

3. According to claim 1, a method for calculating indirect carbon emissions from corporate electricity is characterized in that: In A1, the regional power system transaction flow is calculated according to the following formula: In the above formula, P F,t,l is the transaction flow of branch l of the regional power system during period t, T PTDF is the power transmission distribution factor matrix of the regional power system, are the injected power flows of green power contract combination x and green certificate combination y at grid node n in period t, is the portion of the on-grid loss of branch l during period t allocated to green power trading, Ψ is the conversion function that converts the column vector of the transaction flow branch power flow into the transaction flow branch power flow distribution matrix, is the lossless transaction flow of green power transaction (x+y) on branch l during period t, P A,t,l , They are the actual power flow and actual network loss of branch l in period t respectively.

4. According to claim 1, a method for calculating indirect carbon emissions from corporate electricity is characterized in that: In A3, the indirect carbon emissions from the enterprise's electricity are calculated using the following formula: E cal,t =(Q us,t -Q gr,t -Q se,t -1000N gr )e n,t In the above formula, E cal,t is the indirect carbon emissions of the enterprise’s electricity during period t, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading electricity, and self-generated electricity consumption of new energy in period t, respectively. gr is the number of green certificates, ε n,t is the carbon potential of grid node n during period t.

5. A method for optimizing an enterprise's electricity strategy, characterized in that: The method comprises: B1. Calculate the indirect carbon emissions of the enterprise's electricity using the method described in any one of claims 1 to 4; B2. Construct an optimization model for green electricity strategy of enterprises considering electricity cost and indirect carbon emissions of electricity; B3. Solve the enterprise's green electricity strategy optimization model to obtain the enterprise's optimal electricity strategy.

6. The method for optimizing enterprise electricity consumption strategy according to claim 5, characterized in that: The objective function of the enterprise green electricity strategy optimization model includes: W1=(Q us,t -Q gr,t -Q se,t -1000N gr )γ0 W2=Q gr,t γ1+Q se,t γ2+N gr γ3 W3=(E fp -E cal,t )γ4 In the above formula, F t is the green electricity consumption index of the enterprise in period t, κ is the weight coefficient representing the balance between low carbon and economy, W1, W2, and W3 are the non-green electricity cost, green electricity cost, and carbon quota market income of the enterprise respectively, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading electricity, and self-generated electricity consumption of new energy in period t, respectively. cal,t is the indirect carbon emissions of the enterprise’s electricity during period t, N gr is the number of green certificates, γ0, γ1, γ2, γ3, and γ4 are respectively the ordinary electricity price, the green electricity trading agreement contract price, the cost of self-generated electricity for new energy, the green certificate price, and the carbon quota price. fp Carbon quotas for companies; The constraints include: W1+W2-W3≤W pre AND cal,pre ≤E cal,t In the above formula, W pre For the electricity cost budget of the enterprise, E cal,pre Carbon emission targets set for businesses.

7. An enterprise electricity indirect carbon emission accounting system, characterized in that: The system includes a transaction flow calculation unit, a carbon potential calculation unit, and an indirect carbon emission accounting unit; The transaction flow calculation module is used to obtain the transaction flow of the regional power system based on the green power transaction information; The carbon potential calculation unit is used to calculate the carbon potential of the non-transaction flow part of the grid node n connected to the enterprise according to the actual power flow and the obtained regional power system transaction flow flow; The indirect carbon emissions accounting unit is used to combine the carbon potential of the non-trading flow part of the power grid node n, the enterprise's electricity consumption information and green electricity green certificate information to calculate the enterprise's indirect carbon emissions from electricity.

8. The enterprise electricity indirect carbon emission accounting system according to claim 7 is characterized in that: The regional power system transaction flow is calculated according to the following formula: In the above formula, P F ,t,l is the transaction flow of branch l of the regional power system during period t, T PTDF is the power transmission distribution factor matrix of the regional power system, are the injected power flows of green power contract combination x and green certificate combination y at grid node n in period t, is the portion of the on-grid loss of branch l during period t allocated to green power trading, Ψ is the conversion function that converts the column vector of the transaction flow branch power flow into the transaction flow branch power flow distribution matrix, is the lossless transaction flow of green power transaction (x+y) on branch l during period t, P A ,t,l, are the actual power flow and actual network loss of branch l in period t respectively; The carbon potential of the non-trading flow part of the grid node n connected to the enterprise is calculated according to the following formula: e n,t =[P t NA -(P E,t,l ) T ] -1 (P G,t ) T e G P E,t,l =P A,t,l -P F,t,l In the above formula, ε n,t is the carbon potential of grid node n during period t, P t NA , P G,t , ε G are the node active flux matrix, non-trading unit output matrix, and non-trading unit power generation carbon emission factor vector under the non-trading flow distribution in period t, respectively. A,t,l is the actual power flow of line l during period t, P F,t,l , P E,t,l They are the transaction flow and non-transaction flow of branch l in period t respectively; The indirect carbon emissions from the enterprise's electricity are calculated according to the following formula: E cal,t =(Q us,t -Q gr,t -Q se,t -1000N gr )e n,t In the above formula, E cal,t is the indirect carbon emissions of the enterprise’s electricity during period t, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading electricity, and self-generated electricity consumption of new energy in period t, respectively. gr is the number of green certificates, ε n,t is the carbon potential of grid node n during period t.

9. An enterprise electricity strategy optimization system, characterized in that: The system includes an enterprise electricity indirect carbon emissions accounting module, an optimization model building module, and an optimization model solving module; The enterprise electricity indirect carbon emissions accounting module is used to calculate the enterprise electricity indirect carbon emissions using the method described in any one of claims 1-4; The optimization model building module is used to build an enterprise green electricity strategy optimization model that takes into account the enterprise's electricity costs and indirect carbon emissions from electricity; The optimization model solving module is used to solve the enterprise's green electricity consumption strategy optimization model to obtain the enterprise's optimal electricity consumption strategy.

10. The enterprise electricity strategy optimization system according to claim 9, characterized in that: The objective function of the enterprise green electricity strategy optimization model includes: W1=(Q us,t -Q gr,t -Q se,t -1000N gr )γ0 W2=Q gr,t γ1+Q se,t γ2+N gr γ3 W3=(E fp -E cal,t )γ4 In the above formula, F t is the green electricity consumption index of the enterprise in period t, κ is the weight coefficient representing the balance between low carbon and economy, W1, W2, and W3 are the non-green electricity cost, green electricity cost, and carbon quota market income of the enterprise respectively, Q us,t , Q gr,t , Q se,t are the electricity consumption, green electricity trading electricity, and self-generated electricity consumption of new energy in period t, respectively. cal,t is the indirect carbon emissions of the enterprise’s electricity during period t, N gr is the number of green certificates, γ0, γ1, γ2, γ3, and γ4 are respectively the ordinary electricity price, the green electricity trading agreement contract price, the cost of self-generated electricity for new energy, the green certificate price, and the carbon quota price. fp Carbon quotas for companies; The constraints include: W1+W2-W3≤W pre AND cal,pre ≤E cal,t In the above formula, W pre For the electricity cost budget of the enterprise, E cal,pre Carbon emission targets set for businesses.

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