Peak regulation type energy storage equivalent capacity conversion method and system considering economic cost constraint

Abstract

The invention discloses a peak regulation type energy storage equivalent capacity conversion method and system considering economic cost constraints. The method comprises the following steps: acquiring energy storage and actual operation data of a power grid, and extracting operation parameters of various indexes; determining a reference energy storage system, recording the reference energy storage system as I type, determining various technical parameters of the reference energy storage system, and calculating the whole life cycle total discharge capacity and the whole life cycle cost of the reference energy storage system; solving the to-be-assessed type of stored energy recorded as type II, the required initial configuration capacity and the full life cycle cost thereof by taking the equal total discharge capacity as a target, and recording the to-be-assessed type of stored energy as type II; and S3, judging whether a constraint condition is met or not, and if not, returning to the step S3. According to the method, a double-objective optimization model with technical performance and full-life-cycle economy collaboration is constructed, a multi-type energy storage equivalent peak regulation capacity configuration scheme meeting the technical performance requirement and the economy requirement at the same time is output, and a quantitative and reliable decision basis is provided for energy storage economic operation in a peak regulation scene.

Description

Technical Field

[0001] This application relates to the fields of energy storage capacity equivalence, life cycle cost, and techno-economic synergistic optimization technology, specifically to a method and system for converting the equivalent capacity of peak-shaving energy storage considering economic cost constraints. Background Technology

[0002] In the process of building a new power system dominated by new energy sources, energy storage has become a key technological means to solve the peak-shaving problem of the power grid. Various technological routes exist in the market, including lithium batteries, flow batteries, and compressed air energy storage, with significant differences in their technical characteristics (such as cycle life and degradation characteristics) and economics (such as initial investment and operation and maintenance costs). To scientifically compare and select different energy storage technologies, they need to be compared against a unified benchmark. Existing technologies are usually only calculated based on the technical performance of peak-shaving equivalent capacity. However, the life-cycle cost structure of energy storage power stations is complex, and the cost structures of different types of energy storage vary greatly. A solution with only equivalent peak-shaving capacity but high costs is often unfeasible in practical engineering due to poor economic returns.

[0003] Therefore, there is an urgent need for a comprehensive method for calculating peak-shaving capacity that combines technical equivalence with economic feasibility, in order to improve the economic efficiency of energy storage operation. Summary of the Invention

[0004] In view of the technical problems mentioned in the background, the purpose of this invention is to provide a method and system for calculating the equivalent capacity of peak-shaving energy storage that takes into account economic cost constraints.

[0005] To achieve the objectives of this invention, the technical solution provided by this invention is as follows:

[0006] First aspect

[0007] This application provides a method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints, including the following steps:

[0008] Step S1: Obtain actual operating data of energy storage and power grid, and extract operating parameters of various indicators;

[0009] Step S2: Determine the benchmark energy storage system, denoted as Type I, clarify its various technical parameters, and calculate its total discharge capacity and total life cycle cost;

[0010] Step S3: With the goal of equal total discharge, solve for the required initial configuration capacity and its total life cycle cost of the energy storage type to be evaluated, denoted as Type II;

[0011] Step S4: Determine whether it meets the constraints. If not, return to step S3.

[0012] Second aspect

[0013] This application provides a peak-shaving energy storage equivalent capacity conversion system that considers economic cost constraints, including the following units: a data acquisition unit, a benchmark energy storage system calculation unit, an energy storage type calculation unit to be evaluated, and a constraint condition judgment unit;

[0014] The data acquisition unit is used to acquire actual operating data of energy storage and power grid, and extract operating parameters of various indicators;

[0015] The benchmark energy storage system calculation unit is used to determine the benchmark energy storage system, denoted as Type I, to clarify its various technical parameters and calculate its total discharge capacity and its total life cycle cost.

[0016] The energy storage calculation unit for the type of energy storage to be evaluated is used to solve for the required initial configuration capacity and its full life cycle cost of the type of energy storage to be evaluated, denoted as Type II, with the goal of equal total discharge.

[0017] The constraint condition judgment unit is used to determine whether the constraint condition is met. If not, it returns to the execution of the energy storage calculation unit of the type to be evaluated.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] The basic approach of this invention is to construct a dual-objective optimization model that coordinates technical performance and lifecycle economic efficiency. First, for energy storage systems participating in peak shaving, an equivalent peak shaving capacity conversion model is established based on a specific energy storage system (such as lithium batteries) and the principle of equal total discharge over the entire lifecycle. Second, the lifecycle cost, net present value, and internal rate of return of different types of energy storage are introduced as core economic constraints, requiring that the rates of return for other types of energy storage at the same time scale be within a reasonable threshold range. Finally, the equivalent peak shaving capacity configuration schemes for multiple types of energy storage that simultaneously meet both technical performance and economic requirements are output, providing a quantitative and reliable decision-making basis for the economic operation of energy storage in peak shaving scenarios. Specific effects are as follows:

[0020] I. This patent innovatively and deeply couples "technical equivalence" with "economic feasibility", and for the first time constructs a two-dimensional conversion system of "equivalent total discharge capacity throughout the entire life cycle + economic constraints", which directly fills the technical gap in the industry of "emphasizing technology and neglecting cost", and provides key technical support for energy storage solutions to go from "theoretically feasible" to "engineering implementation".

[0021] II. Overcoming the limitations of single parameters: When calculating the equivalent relationship between the benchmark energy storage system (Type I) and the energy storage system to be evaluated (Type II), this scheme incorporates dynamic technical parameters such as battery state of health (SoH) degradation characteristics, cumulative cycle count over the entire life cycle, and energy conversion efficiency for the first time, thus avoiding the problem of "insufficient actual peak-shaving capacity" caused by ignoring energy storage degradation.

[0022] Achieving full-cycle energy matching: With the core objective of "equal total discharge throughout the entire life cycle" (step S3), rather than short-term power matching, it ensures that Type II energy storage maintains the same peak-shaving output capability as the benchmark system (Type I) throughout its entire lifespan, completely solving the technical defects of "short-term compliance and long-term failure" in traditional conversion, and ensuring the stability and continuity of grid peak shaving.

[0023] III. Precise Quantification of Life Cycle Cost (LCC): By constructing a complete LCC calculation model through formulas 2-6, the energy storage cost is broken down into three major modules: "investment cost (including unit capacity / power cost and land cost), operation cost (including operation and maintenance fees, charging electricity price and discount rate), and recovery cost", so as to achieve full-process cost control from "initial investment" to "retirement recovery".

[0024] Introduce core economic indicators for screening: By using the constraints of "Net Present Value (NPV) and Internal Rate of Return (IRR)" in step S4 (Formulas 8 and 9), directly eliminate the schemes that "meet the technical standards but suffer economic losses".

[0025] Fourth, output the "technologically and economically feasible domain": By traversing different Type II energy storage technologies and adjustable parameters (such as initial capacity, number of cycles, and operation and maintenance strategies), this solution can generate a series of equivalent capacity values ​​that simultaneously meet the requirements of "technological equivalence" and "economic compliance", forming a visualized "feasible solution set" - decision-makers can quickly select the optimal solution for different scenarios without having to calculate them one by one, greatly improving decision-making efficiency.

[0026] This solution provides a set of "quantifiable and reproducible" conversion methods (including clear formulas, steps, and parameter definitions). For example, there are standardized models for calculating the total discharge (Q1) over the entire life cycle of the benchmark system (Type I) and the LCC calculation of the Type II system. This can promote "same-dimensional comparison" of energy storage solutions from different companies and with different technical routes, and accelerate the standardization process of technology selection and cost control in the industry.

[0027] Fifth, this plan, through the dual constraints of "technology + economy", can select a peak-shaving energy storage solution that is "low-cost and highly reliable". Attached Figure Description

[0028] Figure 1 This is a schematic flowchart illustrating a method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints, provided in an embodiment of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown in the figure, this application provides a method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints, including the following steps:

[0031] Step S1: Obtain actual operating data of energy storage and power grid, and extract operating parameters of various indicators;

[0032] Step S2: Determine the benchmark energy storage system, denoted as Type I, clarify its various technical parameters, and calculate its total discharge capacity and total life cycle cost;

[0033] In step S2, the total discharge over its entire lifespan is calculated as follows:

[0034]

[0035] In the formula: E I These represent the initial capacities of energy storage power station I; N I These represent the lifespan of energy storage power station I; K I,i-1 K I,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power station I; The battery health status of energy storage power station I during the j-th cycle; Q I This is the capacity requirement for the entire lifecycle of Energy Storage Station I.

[0036] In step S2, its total lifecycle cost is calculated as follows:

[0037] C I,lcc =C I,inv +C I,om +C I,rec (2)

[0038] In the formula, C I,lcc For the total lifecycle cost of energy storage power station I, C I,inv For the investment cost of energy storage power station I, C I,om For the operating costs of energy storage power station I, C I,rec This represents the recovery cost of Energy Storage Station I.

[0039] Investment cost C invThis refers to the investment cost during the construction phase of an energy storage power station model, which is easily affected by market conditions. The investment cost consists of capacity cost, power cost, and land cost. Specifically, capacity cost refers to the equipment and construction costs related to energy storage capacity in the energy storage power station, such as the cost of individual battery cells, battery containers, capacity-related auxiliary equipment, etc., and the price of capacity cost is easily affected by fluctuations in lithium carbonate prices. Power cost refers to the equipment and construction costs related to power in the energy storage power station, such as the cost of energy storage converters, power-related auxiliary equipment, etc., and the land cost refers to the costs of land purchase, leasing, and construction, calculated using the following formula:

[0040] C inv =U E ·C E +U P ·C P +U D ·C D (3)

[0041] In the formula: U E Cost per unit energy storage capacity; C E For energy storage power station capacity; U P Cost per unit of energy storage power; C P For the power of the energy storage power station; U D Cost per unit land area; C D The land area occupied by the energy storage power station.

[0042] Total life cycle operating cost C om Operating costs refer to the expenses incurred during the operation of an energy storage power station, mainly including operation and maintenance costs, site personnel salaries, electricity purchase costs, plant power costs, equipment replacement costs, and loans. Operating costs are closely related to the scale of the energy storage power station and change as the station's operational lifespan increases. Therefore, the commissioning date needs to be used as the starting point for calculation. The calculation formula considering the impact of the discount rate on operating costs is as follows:

[0043]

[0044] Where: N is the total lifespan of the energy storage power station; λ om (t) represents the percentage of operation and maintenance costs in year t, taken as a percentage of investment cost; i represents the number of years the energy storage power station has been in operation; K i-1 K i ρ represents the cumulative number of cycles at the end of year i-1 and year i after the energy storage system is put into operation; C represents the charging electricity price of the energy storage power station; E S represents the initial capacity of the energy storage system. OH (j) represents the battery health status in the j-th cycle. If the energy storage station does not degrade, this value is 1; η represents the energy conversion efficiency of the energy storage station; and γ represents the discount rate.

[0045] Recovery cost C rec This refers to the difference between the costs incurred in dismantling the energy storage system at the end of its lifespan and the revenue generated from equipment recycling. If the dismantling costs exceed the recycling revenue, the recycling cost is positive; if the dismantling costs are less than the recycling revenue, the recycling cost is negative, as shown in the following formula:

[0046] C rec =C E ·λ rec (5)

[0047] Where, λ rec The unit price is the price per unit capacity for recycling.

[0048] Step S3: With the goal of equal total discharge, solve for the required initial configuration capacity and its total life cycle cost of the energy storage type to be evaluated, denoted as Type II;

[0049] Step S3 includes the following:

[0050] In energy-intensive application scenarios, taking the total output power of an energy storage power station throughout its entire lifecycle as a benchmark, and considering the differences in technical indicators such as degradation characteristics and lifespan of different types of energy storage technologies, an energy storage capacity demand model is established based on equivalent energy conversion as follows:

[0051]

[0052] In the formula: E I E II These represent the initial capacities of energy storage power stations I and II, respectively; N I N II These are the lifespans of energy storage power stations I and II, respectively; K I,i-1 K I,i K II,i-1 K II,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power stations I and II; This represents the battery health status of energy storage power stations I and II during the j-th cycle.

[0053] The calculated E II Substituting the values ​​into the LCC model of a Type II energy storage system, the total life cycle cost is calculated as follows:

[0054] C II,lcc =C II,inv +C II,om +C II,rec (7)

[0055] In the formula, C II,lcc For the total lifecycle cost of energy storage power station Ⅱ, C II,inv For the investment cost of energy storage power station Ⅱ, C II,omFor the operating costs of energy storage power station II, C II,rec This refers to the recovery cost of energy storage power station Ⅱ.

[0056] Step S4: Determine whether it meets the constraints. If not, return to step S3.

[0057] In step S4, determining whether it meets the constraints involves determining whether it meets the internal rate of return and net present value, as follows:

[0058] Net Present Value (NPV) is the difference between the present value of future cash inflows and the present value of future cash outflows. It is a fundamental indicator in the net present value method for project evaluation, as follows:

[0059]

[0060] In the formula: CI represents the cash inflow in each period; CO represents the cash outflow in each period; r is the discount rate, which is generally determined according to the company's minimum rate of return on investment.

[0061] The internal rate of return (IRR) is the discount rate at which the total present value of cash inflows equals the total present value of cash outflows, and the net present value (NPV) equals zero, as follows:

[0062]

[0063] If the internal rate of return (IRR) and net present value (NPV) conditions are met, i.e., NPV is greater than the set threshold (NPV > NPV0) and IRR is greater than the set threshold (IRR > IRR0), then this E II The capacity value ensures both technical equivalence and economic requirements, making it an effective solution; if it does not meet these requirements, then the economics of this type II energy storage configuration is unacceptable, and parameters need to be adjusted or it should be eliminated directly.

[0064] Finally, by traversing different Type II energy storage technologies and their adjustable operating parameters, a series of equivalent capacity values ​​that meet the dual requirements can be obtained, forming a "technological-economic" feasible domain, providing decision-makers with a set of optimal solutions.

[0065] Corresponding to the above method, this application also provides a peak-shaving energy storage equivalent capacity conversion system that considers economic cost constraints, including the following units: a data acquisition unit, a benchmark energy storage system calculation unit, an energy storage type calculation unit to be evaluated, and a constraint condition judgment unit;

[0066] The data acquisition unit is used to acquire actual operating data of energy storage and power grid, and extract operating parameters of various indicators;

[0067] The benchmark energy storage system calculation unit is used to determine the benchmark energy storage system, denoted as Type I, to clarify its various technical parameters and calculate its total discharge capacity and its total life cycle cost.

[0068] The energy storage calculation unit for the type of energy storage to be evaluated is used to solve for the required initial configuration capacity and its full life cycle cost of the type of energy storage to be evaluated, denoted as Type II, with the goal of equal total discharge.

[0069] The constraint condition judgment unit is used to determine whether the constraint condition is met. If not, it returns to the execution of the energy storage calculation unit of the type to be evaluated.

[0070] The total discharge over the entire lifespan of the benchmark energy storage system is calculated as follows:

[0071]

[0072] In the formula: E I These represent the initial capacities of energy storage power station I; N I These represent the lifespan of energy storage power station I; K I,i-1 K I,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power station I; The battery health status of energy storage power station I during the j-th cycle; Q I This is the capacity requirement for the entire lifecycle of Energy Storage Station I.

[0073] Finally, it should be noted that the above embodiments are merely illustrative and explanatory of the present invention, and are not intended to limit the present invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention.

Claims

1. A method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints, characterized in that, Includes the following steps: Step S1: Obtain actual operating data of energy storage and power grid, and extract operating parameters of various indicators; Step S2: Determine the benchmark energy storage system, denoted as Type I, clarify its various technical parameters, and calculate its total discharge capacity and total life cycle cost; Step S3: With the goal of equal total discharge, solve for the required initial configuration capacity and its total life cycle cost of the energy storage type to be evaluated, denoted as Type II; Step S4: Determine whether it meets the constraints. If not, return to step S3.

2. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 1, characterized in that, In step S2, the total discharge over its entire lifespan is calculated as follows: In the formula: E I These represent the initial capacities of energy storage power station I; N I These represent the lifespan of energy storage power station I; K I,i-1 K I,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power station I; The battery health status of energy storage power station I during the j-th cycle; Q I This is the capacity requirement for the entire lifecycle of Energy Storage Station I.

3. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 2, characterized in that, In step S2, its total lifecycle cost is calculated as follows: C I,lcc =C I,inv +C I,om +C I,rec (2) In the formula, C I,lcc For the total lifecycle cost of energy storage power station I, C I,inv For the investment cost of energy storage power station I, C I,om For the operating costs of energy storage power station I, C I,rec This represents the recovery cost of Energy Storage Station I.

4. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 3, characterized in that, Investment cost C inv The calculation formula is as follows: C inv =U E ·C E +U P ·C P +U D ·C D (3) In the formula: U E Cost per unit energy storage capacity; C E For the capacity of the energy storage power station; U P Cost per unit of energy storage power; C P For the power of the energy storage power station; U D Cost per unit land area; C D The land area occupied by the energy storage power station.

5. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 4, characterized in that, Total life cycle operating cost C om The calculation formula is as follows: Where: N is the total lifespan of the energy storage power station; λ om (t) represents the percentage of operation and maintenance costs in year t, taken as a percentage of investment cost; i represents the number of years the energy storage power station has been in operation; K i-1 K i ρ represents the cumulative number of cycles at the end of year i-1 and year i after the energy storage system is put into operation; C represents the charging electricity price of the energy storage power station; E S represents the initial capacity of the energy storage system. OH (j) represents the battery health status in the j-th cycle. If the energy storage station does not degrade, this value is 1; η represents the energy conversion efficiency of the energy storage station; and γ represents the discount rate.

6. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 5, characterized in that, Recovery cost C rec The calculation formula is as follows: C rec =C E ·l rec (5) Where, λ rec The unit price is the price per unit capacity for recycling.

7. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 6, characterized in that, Step S3 includes the following: In energy-intensive application scenarios, taking the total output power of an energy storage power station throughout its entire lifecycle as a benchmark, and considering the differences in technical indicators such as degradation characteristics and lifespan of different types of energy storage technologies, an energy storage capacity demand model is established based on equivalent energy conversion as follows: In the formula: E I E II These represent the initial capacities of energy storage power stations I and II, respectively; N I N II These are the lifespans of energy storage power stations I and II, respectively; K I,i-1 K I,i K II,i-1 K II,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power stations I and II; This represents the battery health status of energy storage power stations I and II during the j-th cycle. The calculated E II Substituting the values ​​into the LCC model of a Type II energy storage system, the total life cycle cost is calculated as follows: C II,lcc =C II,inv +C II,om +C II,rec (7) In the formula, C II,lcc For the total lifecycle cost of energy storage power station Ⅱ, C II,inv For the investment cost of energy storage power station Ⅱ, C II,om For the operating costs of energy storage power station II, C II,rec This refers to the recovery cost of energy storage power station Ⅱ.

8. The method for calculating the equivalent capacity of peak-shaving energy storage considering economic cost constraints according to claim 7, characterized in that, In step S4, determining whether it meets the constraints involves determining whether it meets the internal rate of return and net present value, as follows: Net Present Value (NPV) is the difference between the present value of future cash inflows and the present value of future cash outflows. It is a fundamental indicator in the net present value method for project evaluation, as follows: In the formula: CI represents the cash inflow in each period; CO represents the cash outflow in each period; r is the discount rate, which is generally determined according to the company's minimum rate of return on investment. The internal rate of return (IRR) is the discount rate at which the total present value of cash inflows equals the total present value of cash outflows, and the net present value (NPV) equals zero, as follows: If the internal rate of return and net present value conditions are met, then this E II The capacity value ensures both technical equivalence and economic requirements, making it an effective solution; if it does not meet these requirements, then the economics of this type II energy storage configuration is unacceptable, and parameters need to be adjusted or it should be eliminated directly. By traversing different Type II energy storage technologies and their adjustable operating parameters, a series of equivalent capacity values ​​that meet dual requirements can be obtained, forming a techno-economic feasible domain, providing decision-makers with a set of optimal solutions.

9. A peak-shaving energy storage equivalent capacity conversion system considering economic cost constraints, characterized in that, It includes the following units: data acquisition unit, benchmark energy storage system calculation unit, energy storage type to be evaluated calculation unit, and constraint condition judgment unit; The data acquisition unit is used to acquire actual operating data of energy storage and power grid, and extract operating parameters of various indicators; The benchmark energy storage system calculation unit is used to determine the benchmark energy storage system, denoted as Type I, to clarify its various technical parameters and calculate its total discharge capacity and its total life cycle cost. The energy storage calculation unit for the type of energy storage to be evaluated is used to solve for the required initial configuration capacity and its full life cycle cost of the type of energy storage to be evaluated, denoted as Type II, with the goal of equal total discharge. The constraint condition judgment unit is used to determine whether the constraint condition is met. If not, it returns to the execution of the energy storage calculation unit of the type to be evaluated.

10. A peak-shaving energy storage equivalent capacity conversion system considering economic cost constraints according to claim 9, characterized in that, The total discharge over the entire lifespan of the benchmark energy storage system is calculated as follows: In the formula: E I These represent the initial capacities of energy storage power station I; N I These represent the lifespan of energy storage power station I; K I,i-1 K I,i This represents the cumulative number of cycles at the end of the (i-1)th and ith years after the commissioning of energy storage power station I; The battery health status of energy storage power station I during the j-th cycle; Q I This is the capacity requirement for the entire lifecycle of Energy Storage Station I.

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