A method for calculating carbon footprint of vehicle-to-grid interaction process

Abstract

The application is suitable for the technical field of carbon footprint and vehicle network interaction, and provides a carbon footprint accounting method for vehicle network interaction process based on V2G, which comprises: power grid transmission, V2G charging pile charging conversion, V2G vehicle battery energy storage, calculation of power transmission and loss in the V2G charging pile discharging conversion stage, and calculation of the carbon emission factor of unit power in the power plant in the carbon footprint evaluation stage; then, the total of the power fed back to the power grid by V2G and the power loss in each stage is multiplied by the total greenhouse gas emission factor of unit power to obtain the carbon footprint accounting of the vehicle network interaction process. The application constructs a whole-process greenhouse gas emission calculation framework including power plant power generation, power grid power transmission, V2G charging pile charging and discharging, battery charging and discharging, and power grid feedback, so as to realize the carbon footprint quantification of the whole process of V2G energy flow.

Description

Technical Field

[0001] The present invention relates to the field of carbon footprint and vehicle-grid interaction technology, and in particular to a carbon footprint accounting method for a vehicle-grid interaction process based on V2G. Background Art

[0002] Quantitative assessment of carbon emission intensity has become an important supporting tool for green energy transformation. Carbon footprint evaluation, as a core link in the life cycle assessment (LCA) system, is gradually being widely used in key industries such as electricity, transportation, and construction. It is especially important in the emerging vehicle-to-grid (V2G) interaction model.

[0003] V2G technology refers to the ability of electric vehicles to perform transportation functions while also feeding energy back into the power grid through bidirectional charging and discharging. This not only improves the flexibility and stability of power grid operations, but also plays a key role in peak-valley regulation, emergency power supply, and the absorption of new energy. Electric vehicles charge and store electricity through the V2G mode, and feed it back to the power grid during specific periods of time. This process involves multiple power transmission and conversion links, resulting in varying degrees of energy consumption and greenhouse gas emissions. However, there is currently a lack of systematic carbon footprint assessment tools for the greenhouse gas emissions impact of the entire V2G interaction process. Traditional research has focused on the economic and technical performance of V2G, but its environmental impact assessment is not in-depth enough. In particular, there is a lack of a unified evaluation framework based on stage decomposition and detailed calculation of emission factors. This makes it difficult to quantify its green benefits, which restricts the large-scale promotion of V2G.

[0004] Therefore, it is necessary to propose a scientific, systematic and standardized V2G interaction carbon footprint estimation method to quantify the carbon emissions from the entire process of power acquisition, transmission, storage, release to grid feedback, and provide a theoretical basis and decision-making basis for V2G system optimization design, carbon trading and environmental certification. Summary of the Invention

[0005] The present invention provides a carbon footprint accounting method for the vehicle-grid interaction process based on V2G to solve the technical problems mentioned in the background technology.

[0006] A carbon footprint calculation method for a vehicle-to-grid interaction process based on V2G, the method comprising the following steps:

[0007] The calculation of the electric energy transmitted and lost during the grid transmission, V2G charging pile charging conversion, V2G vehicle battery energy storage, and V2G charging pile discharge conversion stages, as well as the calculation of the carbon emission factor per unit of electricity emitted by the power plant in the carbon footprint assessment stage, are then used to multiply the sum of the electric energy fed back to the grid by V2G and the electric energy lost in each stage by the total greenhouse gas emission factor per unit of electricity to obtain the carbon footprint accounting of the vehicle-grid interaction process.

[0008] As a further technical solution of the present invention, the formula for calculating the electric energy transmitted and lost during the power grid transmission phase is:

[0009] Formula 1: ;

[0010] Formula 2: ;

[0011] Where, The electric energy is transmitted to the V2G charging pile through the power grid transmission stage. The electricity transmitted to the power plant, is the line loss rate, The electric energy lost during the transmission phase to the grid.

[0012] As a further technical solution of the present invention, the formula for calculating the electric energy transmitted and lost during the charging conversion phase of a V2G charging pile is:

[0013] Formula 3: ;

[0014] Formula 4: ;

[0015] Where, It is the electric energy transmitted to the V2G vehicle battery through the V2G charging pile charging conversion stage. For V2G charging pile charging conversion efficiency, The electric energy lost during the charging conversion phase of the V2G charging pile.

[0016] As a further technical solution of the present invention, the formula for calculating the electric energy transmitted and lost during the battery energy storage phase of a V2G vehicle is:

[0017] Formula 5: ;

[0018] Formula 6: ;

[0019] Where, The electric energy is transmitted to the V2G charging pile after the V2G vehicle battery storage stage. is the charge and discharge efficiency of the V2G vehicle battery, It is the electric energy lost during the battery energy storage stage of the V2G vehicle.

[0020] As a further technical solution of the present invention, the formula for calculating the electric energy transmitted and lost during the discharge conversion phase of a V2G charging pile is:

[0021] Formula 7: ;

[0022] Formula 8: ;

[0023] Where, It is the electric energy fed back to the grid after the discharge conversion stage of the V2G vehicle charging pile. is the discharge conversion efficiency of the V2G charging pile, This is the electric energy lost during the discharge conversion phase of the V2G charging pile.

[0024] As a further technical solution of the present invention, in the carbon footprint assessment stage, the carbon emission factor of the power plant per unit of electricity is calculated, that is, the total greenhouse gas per unit of electricity ( ) emission factors, including: greenhouse gas (CO2, N2O, CH4) emissions per unit of electricity generated by the power plant multiplied by its global warming potential (GWP) (usually with CO2 as a reference) to obtain the greenhouse gas emission factor per unit of electricity generated by the power plant, that is, the carbon emission factor; then, the carbon footprint of the vehicle-grid interaction process is calculated by multiplying the sum of the electricity fed back to the grid by V2G and the electricity lost in each stage by the total greenhouse gas emission factor per unit of electricity. The calculation formula is:

[0025] Formula 9: ;

[0026] Formula 10: ;

[0027] Where, is the total greenhouse gas emission factor ( ), CO2 emissions per unit of electricity generated by a power plant ( ), The CH4 emissions per unit of electricity generated by the power plant ( ), N2O emissions per unit of electricity generated by the power plant ( ), is the global warming potential, , , Refer to IPCC 2006, is the power generation efficiency of the power plant, for The number of megajoules of electrical energy, For unit conversion, is the carbon dioxide equivalent of the V2G vehicle-grid interaction process.

[0028] Beneficial effects achieved by the present invention:

[0029] The present invention provides a carbon footprint estimation method based on the V2G interaction process, constructing a greenhouse gas emission calculation framework for the entire process, including power plant power generation, grid transmission, V2G charging pile charging and discharging, battery charging and discharging, and grid feedback, thereby realizing the quantification of the carbon footprint of the entire V2G energy flow process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the carbon footprint calculation process of the V2G vehicle-grid interaction process of the present invention. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below. 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 creative efforts are within the scope of protection of the present invention.

[0032] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0033] See also Figure 1 The embodiment of the present invention provides a carbon footprint accounting method for a vehicle-to-grid interaction process based on V2G, the method comprising the following steps:

[0034] The calculation of the electric energy transmitted and lost during the grid transmission, V2G charging pile charging conversion, V2G vehicle battery energy storage, and V2G charging pile discharge conversion stages, as well as the calculation of the carbon emission factor per unit of electricity emitted by the power plant in the carbon footprint assessment stage, are then used to multiply the sum of the electric energy fed back to the grid by V2G and the electric energy lost in each stage by the total greenhouse gas emission factor per unit of electricity to obtain the carbon footprint accounting of the vehicle-grid interaction process.

[0035] In this embodiment, the formula for calculating the electric energy transmitted and lost during the power grid transmission phase is:

[0036] Formula 1: ;

[0037] Formula 2: ;

[0038] Where, The electric energy is transmitted to the V2G charging pile through the power grid transmission stage. The electricity transmitted to the power plant, is the line loss rate, The electric energy lost during the transmission phase to the grid.

[0039] In this embodiment, the formula for calculating the electric energy transmitted and lost during the charging conversion phase of the V2G charging pile is:

[0040] Formula 3: ;

[0041] Formula 4: ;

[0042] Where, It is the electric energy transmitted to the V2G vehicle battery through the V2G charging pile charging conversion stage. For V2G charging pile charging conversion efficiency, The electric energy lost during the charging conversion phase of the V2G charging pile.

[0043] In this embodiment, the formula for calculating the electric energy transmitted and lost during the V2G vehicle battery energy storage phase is:

[0044] Formula 5: ;

[0045] Formula 6: ;

[0046] Where, The electric energy is transmitted to the V2G charging pile after the V2G vehicle battery storage stage. is the charge and discharge efficiency of the V2G vehicle battery, It is the electric energy lost during the battery energy storage stage of the V2G vehicle.

[0047] In this embodiment, the formula for calculating the electric energy transmitted and lost during the discharge conversion phase of the V2G charging pile is:

[0048] Formula 7: ;

[0049] Formula 8: ;

[0050] Where, It is the electric energy fed back to the grid after the discharge conversion stage of the V2G vehicle charging pile. is the discharge conversion efficiency of the V2G charging pile, This is the electric energy lost during the discharge conversion phase of the V2G charging pile.

[0051] In this embodiment, during the carbon footprint assessment phase, the carbon emission factor per unit of electricity generated by the power plant is calculated, i.e., the total greenhouse gas emissions per unit of electricity ( ) emission factors, including: greenhouse gas (CO2, N2O, CH4) emissions per unit of electricity generated by the power plant multiplied by its global warming potential (GWP) (usually with CO2 as a reference) to obtain the greenhouse gas emission factor per unit of electricity generated by the power plant, that is, the carbon emission factor; then, the carbon footprint of the vehicle-grid interaction process is calculated by multiplying the sum of the electricity fed back to the grid by V2G and the electricity lost in each stage by the total greenhouse gas emission factor per unit of electricity. The calculation formula is:

[0052] Formula 9: ;

[0053] Formula 10: ;

[0054] Where, is the total greenhouse gas emission factor ( ), CO2 emissions per unit of electricity generated by a power plant ( ), The CH4 emissions per unit of electricity generated by the power plant ( ), N2O emissions per unit of electricity generated by the power plant ( ), is the global warming potential, , , Refer to IPCC 2006, is the power generation efficiency of the power plant, for The number of megajoules of electrical energy, For unit conversion, is the carbon dioxide equivalent of the V2G vehicle-grid interaction process.

[0055] In order to make the implementation steps of the present invention clear, examples are used to describe them in detail.

[0056] Assume that the power plant generates 60 The carbon footprint of the V2G vehicle-grid interaction process is now calculated.

[0057] (1) Calculation of electric energy transmission and loss during the power grid transmission stage (the line loss rate of China's power companies in 2020 was 5.6%, ):

[0058] ;

[0059] ;

[0060] (2) Calculation of the power transmission and loss during the charging conversion phase of the V2G charging pile (the charging conversion efficiency of the V2G charging pile is 83.5%-99.2%, taking ):

[0061] ;

[0062] ;

[0063] (3) Calculation of electric energy transmitted and lost during the battery energy storage phase of V2G vehicles (ternary lithium battery: fast charge 94.58%, slow charge: 97.44%, lithium iron phosphate battery: slow charge 96.64%, fast charge 92.67%, take ):

[0064] ;

[0065] ;

[0066] (4) Calculation of the power transmission and loss during the discharge conversion phase of the V2G charging pile (the reverse discharge efficiency of the V2G charging pile is 78.2%-92%, ):

[0067] ;

[0068] ;

[0069] (5) In the carbon footprint assessment phase, the carbon emission factor per unit of electricity generated by the power plant and the carbon footprint of the vehicle-grid interaction process are calculated (taking a coal-fired power plant as an example, , , , , , , ):

[0070] ;

[0071] ;

[0072] Therefore, the thermal power plant emits 60 The V2G vehicle-grid interaction can actually feedback 48.237 to the power grid, and the carbon footprint of the V2G vehicle-grid interaction process is , it can reduce the daytime power plant of carbon dioxide equivalent.

[0073] It should be noted that, in this document, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0074] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the description of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A carbon footprint accounting method for the vehicle-grid interaction process based on V2G, characterized in that: The method comprises the following steps: Calculate the energy transmitted and lost during the grid transmission, V2G charging station charging conversion, V2G vehicle battery energy storage, and V2G charging station discharge conversion phases. During the carbon footprint assessment phase, calculate the carbon emission factor per unit of electricity generated by the power plant. Then, multiply the total greenhouse gas emission factor per unit of electricity by the sum of the V2G energy fed back to the grid and the energy lost at each stage by the total greenhouse gas emission factor per unit of electricity to arrive at the carbon footprint of the vehicle-grid interaction process. During the carbon footprint assessment phase, the calculation of the carbon emission factor per unit of electricity generated by the power plant, i.e., the total greenhouse gas emission factor per unit of electricity, includes: multiplying the greenhouse gas emissions per unit of electricity generated by the power plant by its global warming potential (GWP) to obtain the greenhouse gas emission factor per unit of electricity generated by the power plant, i.e., the carbon emission factor; and then multiplying the total greenhouse gas emission factor per unit of electricity by the sum of the electricity fed back to the grid by V2G and the electricity lost at each stage to obtain the carbon footprint accounting of the vehicle-grid interaction process. The calculation formula is: Formula 9: ; Formula 10: ; Where, is the total greenhouse gas emission factor, The CO2 emissions per unit of electricity generated by the power plant, is the CH4 emission per unit of electricity generated by the power plant, is the N2O emission per unit of electricity generated by the power plant, is the global warming potential, , , , is the power generation efficiency of the power plant, for The number of megajoules of electrical energy, For unit conversion, is the carbon dioxide equivalent of the V2G vehicle-grid interaction process; The electric energy lost during the transmission phase to the power grid; The electric energy lost during the charging conversion phase of the V2G charging pile; The electric energy lost during the battery storage phase of the V2G vehicle; This is the electric energy lost during the discharge conversion phase of the V2G charging pile.

2. The carbon footprint calculation method for the V2G-based vehicle-grid interaction process according to claim 1 is characterized in that: The calculation formula for electric energy transmitted and lost during the power grid transmission phase is: Formula 1: ; Formula 2: ; Where, The electric energy is transmitted to the V2G charging pile through the power grid transmission stage. The electricity transmitted to the power plant, is the line loss rate.

3. The carbon footprint calculation method for the V2G-based vehicle-grid interaction process according to claim 1 is characterized in that: The formula for calculating the power transmitted and lost during the charging conversion phase of a V2G charging pile is: Formula 3: ; Formula 4: ; Where, It is the electric energy transmitted to the V2G vehicle battery through the V2G charging pile charging conversion stage. Charging conversion efficiency of V2G charging pile.

4. The carbon footprint calculation method for the V2G-based vehicle-grid interaction process according to claim 1 is characterized in that: The formula for calculating the electric energy transmitted and lost during the V2G vehicle battery energy storage phase is: Formula 5: ; Formula 6: ; Where, The electric energy is transmitted to the V2G charging pile after the V2G vehicle battery storage stage. is the charge and discharge efficiency of the V2G vehicle battery.

5. The carbon footprint calculation method for the V2G-based vehicle-grid interaction process according to claim 1 is characterized in that: The formula for calculating the power transmitted and lost during the discharge conversion phase of a V2G charging pile is: Formula 7: ; Formula 8: ; Where, It is the electric energy fed back to the grid after the discharge conversion stage of the V2G vehicle charging pile. is the discharge conversion efficiency of the V2G charging pile.

Images