CN117726190A - A method and system for economic evaluation of shared energy storage based on the whole life cycle - Google Patents

Abstract

The invention discloses a shared energy storage economical evaluation method and system based on a full life cycle, and belongs to the technical field of power system planning and configuration. The method comprises the following steps: s1, determining an energy storage type and determining system parameters of the energy storage type; s2, constructing a shared energy storage optimal configuration model based on the system parameters, and carrying out capacity optimal configuration on the energy storage type based on the shared energy storage optimal configuration model; and evaluating the method of the optimal configuration to obtain an evaluation result. The model adopts a full life cycle cost theory, and allows the whole energy storage system to maximize economic benefit in the full life cycle.

Description

A method and system for evaluating the economic performance of shared energy storage based on the entire life cycle

Technical Field

The present invention belongs to the technical field of power system planning and configuration, and specifically relates to a method and system for evaluating the economic efficiency of shared energy storage based on the entire life cycle.

Background Art

With the implementation of the supporting policies for my country's power system reform, the application value and commercial development of grid energy storage have gradually received attention and recognition from the market. Energy storage is an important supporting technology for building a new power system dominated by new energy. It has become an important means to build a "new energy + energy storage" application model and solve the problem of new energy consumption. In actual operation, new energy supports energy storage, and the traditional energy storage model has a short energy storage time and lacks a mature and stable profit model, which greatly increases the investment cost of new energy power stations. Shared energy storage provides a new path for the development of energy storage. The "sharing" of shared energy storage breaks the boundaries of the original energy storage application, provides a new path for the development of energy storage, improves the profitability of the project, and shortens the investment recovery cycle. However, the commercial operation model of shared energy storage is still in the exploratory stage, but my country's current energy storage industry policy is not yet perfect, investors bear high risks, and the commercialization process is relatively slow. Therefore, it is also of great significance to carry out research on the economic benefit evaluation factors of shared energy storage.

Summary of the invention

The present invention aims to address the deficiencies of the prior art and proposes a method and system for evaluating the economic feasibility of shared energy storage based on the entire life cycle, which is used for configuration optimization to help decision makers determine whether an energy storage system needs to be introduced and to determine its optimal selection and construction scale cost.

To achieve the above object, the present invention provides the following solution: a method for evaluating the economic efficiency of shared energy storage based on the entire life cycle, comprising the following steps:

S1. Determine the energy storage type and determine the system parameters of the energy storage type;

S2. Constructing a shared energy storage optimization configuration model based on the system parameters, and performing capacity optimization configuration on the energy storage type based on the shared energy storage optimization configuration model; and evaluating the optimization configuration method to obtain an evaluation result.

Further preferably, the energy storage types include: lithium-ion batteries, pumped storage, compressed air storage, carbon-lead batteries and vanadium flow batteries;

The system parameters include: initial investment cost, annual operation and maintenance cost, life span, residual value, number of operations, discharge depth, cycle efficiency and cost per kilowatt-hour.

Further preferably, the shared energy storage optimization configuration model includes: an objective function and constraint conditions;

The objective function adopts the maximum value of net profit, including: the investment cost of the shared energy storage power station over the entire life cycle and the income of the shared energy storage power station;

The constraint conditions include: equality constraint conditions and inequality constraint conditions.

Further preferably, the life cycle investment cost of the shared energy storage power station includes: initial investment cost, operation and maintenance cost during the life cycle, and residual value of the shared energy storage power station;

The initial investment costs include:

C _inv = C _p P + C _e E,

In the formula, C _inv represents the initial investment cost, C _p represents the unit charging/discharging power cost of shared energy storage, P represents the rated power value of shared energy storage, _Ce represents the unit capacity cost of shared energy storage, and E represents the rated capacity of shared energy storage;

The operation and maintenance costs during the whole life cycle include:

_Cope = k _r C _m P,

In the formula, C _ope represents the operation and maintenance cost during the whole life cycle, k _r represents the calculation coefficient of the whole life cycle, and C _m represents the annual operation and maintenance cost per unit charge and discharge power of the shared energy storage;

The residual value of the shared energy storage power station includes:

C _Rec = C _inv × K _Rec ,

Where C _Rec represents the residual value of the shared energy storage power station, and K _Rec represents the ratio of the residual value of the power station to the initial investment.

Further preferably, the equation agreed conditions include: system balance constraint, energy storage charge state continuity constraint and energy storage initial and final charge state consistency constraint;

The system balance constraints include:

P _grid (t)=P _ch (t)+P _load (t)-P _dis (t),

Where P _grid (t) represents the power supply of the grid in period t, P _dis (t) represents the power discharged from the shared energy storage to the distribution network in period t, P _ch (t) represents the power charged from the shared energy storage to the distribution network in period t, and P _load (t) represents the power load of the distribution network in period t.

The energy storage charge state continuity constraint includes:

Where, S _soc,t+1 represents the state of charge of the energy storage at time t+1, S _soc,t represents the state of charge of the energy storage at time t; η _c and η _d represent the energy storage charging and discharging efficiency, respectively, E represents the rated capacity of the shared energy storage, and Δt represents the state duration at time t;

The energy storage initial and final state of charge consistency constraints include:

S _soc (1) = S _soc (T),

Where S _soc (1) represents the initial state of charge of the energy storage, and T represents the total number of time periods in a charge and discharge cycle.

Further preferably, the inequality constraints include: energy storage charge/discharge state constraints, energy storage charge/discharge power constraints, and energy storage charge state constraints;

The energy storage charge/discharge state constraints include:

S _dis,t +S _ch,t ≤1,

Wherein, Sch _,t and Sdis _,t represent the actual charging and discharging states of the energy storage at time t, respectively, and are 0-1 variables, where 1 represents the charging state and 0 represents the discharging state;

The energy storage charging/discharging power constraints include:

In the formula, P _dis represents the energy storage discharge power, and P _ch represents the energy storage charging power;

The upper and lower limit constraints of the energy storage charge state include:

0.1E＝S _min ≤S _soc ≤S _max ＝0.9E

In the formula, E represents the rated capacity of the energy storage power station, S _min and S _max represent the minimum and maximum values of the energy storage state of charge, respectively, and S _soc represents the energy storage state of charge.

Further preferably, the method for evaluating the configuration optimization method and obtaining the evaluation result includes:

The net income, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the optimization configuration method to obtain the evaluation result.

The present invention also provides a shared energy storage economic evaluation system based on the entire life cycle, the evaluation system is used to implement the above evaluation method, including: a first evaluation unit and a second evaluation unit;

The first evaluation unit is used to determine the energy storage type and determine the system parameters of the energy storage type;

The second evaluation unit is used to construct a shared energy storage optimization configuration model based on the system parameters, and to perform capacity optimization configuration on the energy storage type based on the shared energy storage optimization configuration model; and to evaluate the optimization configuration method to obtain an evaluation result.

Further preferably, the shared energy storage optimization configuration model includes: an objective function and constraint conditions;

The objective function adopts the maximum value of net profit, including: the investment cost of the shared energy storage power station over the entire life cycle and the income of the shared energy storage power station;

The constraint conditions include: equality constraint conditions and inequality constraint conditions.

Further preferably, the method for the second evaluation unit to obtain the evaluation result includes:

The net income, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the optimization configuration method to obtain the evaluation result.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The model adopts the life cycle cost theory, allowing the entire energy storage system to maximize its economic benefits throughout its life cycle.

(2) The model has a wide range of applicability and is generally applicable, especially to the configuration of shared energy storage. It is also applicable to the operation optimization link. Specifically, it only needs to convert the cost-benefit composition to a certain operation year/day.

(3) In view of the current problems in my country's energy storage industry, such as imperfect policies and high risks for investors, the model can provide a certain reference for benefit evaluation and help promote the commercialization process of the energy storage industry.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic flow chart of a method for evaluating the economic efficiency of shared energy storage based on the entire life cycle according to an embodiment of the present invention.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

Embodiment 1:

The ideas, modes and models of the shared energy storage economic benefit model based on the life cycle cost theory adopted by the present invention are described as follows:

(1) Planning ideas:

In order to evaluate whether the shared energy storage integrated configuration system is profitable, choosing the appropriate new energy penetration rate and the return on investment of different types of energy storage is the key to profitability. Consider increasing the power generation of new energy power stations and improving the proportion of new energy consumption, so as to maximize the net benefit of shared energy storage. Introducing adjustable resources, that is, the shared energy storage system can further enhance the peak-shaving capacity of the power grid. On the one hand, the shared energy storage integrated configuration system stabilizes the fluctuation of power grid load by utilizing a reasonable new energy penetration rate, and on the other hand, it improves the flexibility and stability of the system by reasonably configuring the capacity and type of energy storage, which reduces the total cost of the planning scheme while meeting the needs of energy transmission and flexible adjustment, and improves the net profit of the planning scheme.

(2) Planning model

This paper mainly studies the benefit evaluation model of an integrated shared energy storage system under the long-term planning time scale, that is, the entire life cycle.

Considering the multi-time scale distribution characteristics of the regulation capacity demand in the new power system, it is necessary to have an integrated configuration method for multiple types of shared energy storage to meet the regulation demand. Considering the different cost-benefit of shared energy storage under different configurations, the benefits of shared energy storage systems are also different. In order to intuitively see the benefits of shared energy storage systems of different schemes and use this as a basis for judging whether the scheme is profitable or not, it is very important to establish a unified benefit evaluation model for shared energy storage systems.

Specifically, as shown in FIG1 , this embodiment provides a method for evaluating the economic efficiency of shared energy storage based on the entire life cycle, comprising the following steps:

S1. Determine the energy storage type and the system parameters of the energy storage type.

Shared energy storage power stations are a flexible energy storage solution that can target different application scenarios, such as: peak-valley electricity price utilization, renewable energy smoothing, backup power supply, power system stability improvement, etc., and select different solutions according to different energy storage types.

Among them, energy storage types include: lithium-ion batteries, pumped storage, compressed air storage, carbon-lead batteries and vanadium liquid flow batteries; system parameters include: initial investment cost, annual operation and maintenance cost, life, residual value, number of operations, discharge depth, cycle efficiency and cost per kilowatt-hour.

Table 1

Some system parameters of different energy storage types are shown in Table 1.

S2. Construct a shared energy storage optimization configuration model based on system parameters, and optimize the capacity of energy storage types based on the shared energy storage optimization configuration model; and evaluate the optimization configuration method to obtain evaluation results.

The shared energy storage optimization configuration model includes: objective function and constraints; in order to maximize the benefits after configuration and make the benefits most significant, the objective function adopts the maximum value of net profit, including: the investment cost of the shared energy storage power station over the entire life cycle and the benefits of the shared energy storage power station; the constraints include: equality constraints and inequality constraints.

In this embodiment, the model is expressed as:

maxF ₁ =f ₁ +f ₂ +f ₃ +C _Rec -C _inv -C _ope ,

Where _f1 , _f2 , and _f3 represent peak-valley arbitrage, service management income of shared energy storage power stations, and income from absorbing new energy, respectively; _Cinv represents the initial investment cost, _Cope represents the operation and maintenance cost over the entire life cycle, and _Crec represents the residual value of the shared energy storage power station.

The benefits of shared energy storage power stations include: peak-valley arbitrage, shared energy storage power station service management benefits, and benefits from absorbing new energy.

Specifically, the peak-valley arbitrage benefits can be evaluated by the actual charging and discharging power of the energy storage at time i. The evaluation methods include:

f ₁ = DS ₁ k _r ,

In the formula, D represents the annual operating days of energy storage, _kr represents the calculation coefficient of the entire life cycle, and _S1 represents the peak-valley arbitrage income.

in,

Where _NT represents the number of dispatch periods, Pch _,t and Pdis _,t represent the actual charging and discharging power of the energy storage at time t, _Sch,t and Sdis _,t represent the actual charging and discharging states of the energy storage at time t, _Ptime represents the electricity price at time t, and Δt represents the state duration at time t.

Where T represents the total number of time periods in a charge and discharge cycle, t _r represents the inflation rate, and d _r represents the discount rate.

The service management income of shared energy storage power stations includes frequency regulation auxiliary service income and peak regulation auxiliary service income; the frequency regulation auxiliary service income is calculated by the peak regulation reported capacity; the frequency regulation auxiliary service income is calculated by the frequency regulation mileage. The service management income of shared energy storage power stations can be evaluated by the actual purchase and sale power of energy storage at time i. The evaluation methods include:

f ₂ = DS ₂ k _r ,

in,

Where θ(t) represents the unit price of the service fee charged by the energy storage power station during period t, P _ess,b represents the power purchased by the energy storage power station during period t, and P _ess,s represents the power sold by the energy storage power station during period t.

The benefits of absorbing new energy can be evaluated through the energy storage charging and discharging efficiency and the electricity price of new energy backup capacity. The evaluation methods include:

f ₃ =DS ₃ k _r ,

in,

In the formula, m represents the contractual electricity price of renewable energy, and P _t ^new represents the abandoned power of renewable energy of the shared energy storage power station at time t.

The full life cycle investment cost of a shared energy storage power station includes: initial investment cost, operation and maintenance cost during the full life cycle, and the residual value of the shared energy storage power station.

Initial investment costs include:

C _inv = C _p P + C _e E,

Where C _inv represents the initial investment cost, C _p represents the unit charging/discharging power cost of the contributed energy storage, P represents the rated power value of the shared energy storage, _Ce represents the unit capacity cost of the shared energy storage, and E represents the rated capacity of the shared energy storage.

The operation and maintenance costs during the whole life cycle include:

_Cope = k _r C _m P,

In the formula, _Cope represents the operation and maintenance cost during the whole life cycle, _kr represents the calculation coefficient of the whole life cycle, and _Cm represents the annual operation and maintenance cost per unit charging and discharging power of shared energy storage.

The residual value of a shared energy storage power station can be evaluated by the initial investment cost and the ratio of the residual value of the power station to the initial investment. The evaluation methods include:

C _Rec = C _inv × K _Rec ,

Where C _Rec represents the residual value of the shared energy storage power station, and K _Rec represents the ratio of the residual value of the power station to the initial investment.

The agreed conditions of the equation include: system balance constraints, energy storage charge state continuity constraints, and energy storage initial and final charge state consistency constraints.

System balance constraints include:

P _grid (t)=P _ch (t)+P _load (t)-P _dis (t),

Where P _grid (t) represents the power supply of the grid during period t, P _dis (t) represents the power discharged from the shared energy storage to the distribution network during period t, P _ch (t) represents the power charged by the shared energy storage to the distribution network during period t, and P _load (t) represents the power load of the distribution network during period t.

Energy storage state of charge continuity constraints include:

In the formula, S _soc,t+1 represents the state of charge of the energy storage at time t+1, S _soc,t represents the state of charge of the energy storage at time t, that is, the state of the system at time t+1 is related to the charge and discharge state at time t; η _c and η _d represent the energy storage charge and discharge efficiency respectively, E represents the rated capacity of the shared energy storage, and Δt represents the state duration at time t;

The energy storage charge state consistency constraints include:

S _soc (1) = S _soc (T),

Where S _soc (1) represents the initial state of charge of the energy storage, and T represents the total number of time periods in a charge and discharge cycle.

Inequality constraints include: energy storage charge/discharge state constraints, energy storage charge/discharge power constraints, and energy storage charge state constraints;

Energy storage charge/discharge state constraints include:

S _dis,t +S _ch,t ≤1,

Wherein, _Sch,t and Sdis _,t represent the actual charging and discharging states of the energy storage at time t respectively; they are 0-1 variables, where 1 represents the charging state and 0 represents the discharging state.

Energy storage charging/discharging power constraints include:

Wherein, P _dis represents the energy storage discharging power, and P _ch represents the energy storage charging power.

The upper and lower limit constraints of energy storage charge state include:

0.1E＝S _min ≤S _soc ≤S _max ＝0.9E

In the formula, E represents the rated capacity of the energy storage power station, S _min and S _max represent the minimum and maximum values of the energy storage state of charge, respectively, and S _soc represents the energy storage state of charge.

In this embodiment, the capacity configuration of the shared energy storage system is optimized, the cplex solver is called to solve, and the solution result is output, that is, the energy storage configuration power, capacity, net income within the full life cycle of the shared energy storage, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the benefit of the optimization configuration method and obtain the evaluation result.

Among them, net income includes:

F ₁ =S ₁ +S ₂ +S ₃ -C _inv -C _ope +C _rec .

The dynamic payback period includes:

In the formula, _Pt represents the dynamic investment payback period, _CIn represents the cash inflow in the nth year, _COn represents the cash outflow in the nth year, and BY represents the benchmark rate of return.

The evaluation criteria are: compare the dynamic investment payback period _Pt with the standard investment payback period _Ps . If _Pt < _Ps , the solution is feasible, and the smaller T is, the better the solution is; otherwise, the solution is not feasible.

The internal rate of return includes:

In the formula, N represents the operating life of the energy storage power station, IRR represents the internal rate of return, and _Cn represents the net cash flow in the nth year.

The evaluation criteria are: compared with the benchmark rate of return BY, if IRR>BY, the project plan is economically feasible; if IRR<BY, the project plan is economically infeasible.

Based on the integrated application scenarios of multiple types of shared energy storage, the shared energy storage backup plan is substituted into the system model to obtain the results. The obtained results are evaluated individually or jointly through the shared energy storage economic evaluation indicators, and the best economic plan is selected based on the evaluation results.

Embodiment 2:

This embodiment provides a shared energy storage economic evaluation system based on the entire life cycle, including: a first evaluation unit and a second evaluation unit;

The first evaluation unit is used to determine the energy storage type and determine system parameters of the energy storage type.

Shared energy storage power stations are a flexible energy storage solution that can target different application scenarios, such as: peak-valley electricity price utilization, renewable energy smoothing, backup power supply, power system stability improvement, etc., and different solutions can be selected according to different energy storage types.

Among them, energy storage types include: lithium-ion batteries, pumped storage, compressed air storage, carbon-lead batteries and vanadium liquid flow batteries; system parameters include: initial investment cost, annual operation and maintenance cost, life, residual value, number of operations, discharge depth, cycle efficiency and cost per kilowatt-hour.

The second evaluation unit is used to construct a shared energy storage optimization configuration model based on system parameters, and to optimize the capacity of energy storage types based on the shared energy storage optimization configuration model; and to evaluate the optimization configuration method to obtain an evaluation result.

The shared energy storage optimization configuration model includes: objective function and constraints; in order to maximize the benefits after configuration and make the benefits most significant, the objective function adopts the maximum value of net profit, including: the investment cost of the shared energy storage power station over the entire life cycle and the benefits of the shared energy storage power station; the constraints include: equality constraints and inequality constraints.

In this embodiment, the model is expressed as:

maxF ₁ =f ₁ +f ₂ +f ₃ +C _Rec -C _inv -C _ope ,

Where _f1 , _f2 , and _f3 represent peak-valley arbitrage, service management income of shared energy storage power stations, and income from absorbing new energy, respectively; _Cinv represents the initial investment cost, _Cope represents the operation and maintenance cost over the entire life cycle, and _Crec represents the residual value of the shared energy storage power station.

The benefits of shared energy storage power stations include: peak-valley arbitrage, shared energy storage power station service management benefits, and benefits from absorbing new energy.

Specifically, the peak-valley arbitrage benefits can be evaluated by the actual charging and discharging power of the energy storage at time i. The evaluation methods include:

f ₁ = DS ₁ k _r ,

In the formula, D represents the annual operating days of energy storage, _kr represents the calculation coefficient of the entire life cycle, and _S1 represents the peak-valley arbitrage income.

in,

Where _NT represents the number of dispatch periods, Pch _,t and Pdis _,t represent the actual charging and discharging power of the energy storage at time t, _Sch,t and Sdis _,t represent the actual charging and discharging states of the energy storage at time t, _Ptime represents the electricity price at time t, and Δt represents the state duration at time t.

Where T represents the total number of time periods in a charge and discharge cycle, t _r represents the inflation rate, and d _r represents the discount rate.

The service management income of shared energy storage power stations includes frequency regulation auxiliary service income and peak regulation auxiliary service income; the frequency regulation auxiliary service income is calculated by the peak regulation reported capacity; the frequency regulation auxiliary service income is calculated by the frequency regulation mileage. The service management income of shared energy storage power stations can be evaluated by the actual purchase and sale power of energy storage at time i. The evaluation methods include:

f ₂ = DS ₂ k _r ,

in,

Where θ(t) represents the unit price of the service fee charged by the energy storage power station during period t, P _ess,b represents the power purchased by the energy storage power station during period t, and P _ess,s represents the power sold by the energy storage power station during period t.

The benefits of absorbing new energy can be evaluated through the energy storage charging and discharging efficiency and the electricity price of new energy backup capacity. The evaluation methods include:

f ₃ =DS ₃ k _r ,

in,

In the formula, m represents the contractual electricity price of renewable energy, and P _t ^new represents the abandoned power of renewable energy of the shared energy storage power station at time t.

The full life cycle investment cost of a shared energy storage power station includes: initial investment cost, operation and maintenance cost during the full life cycle, and the residual value of the shared energy storage power station.

Initial investment costs include:

C _inv = C _p P + C _e E,

Where C _inv represents the initial investment cost, C _p represents the unit charging/discharging power cost of the contributed energy storage, P represents the rated power value of the shared energy storage, _Ce represents the unit capacity cost of the shared energy storage, and E represents the rated capacity of the shared energy storage.

The operation and maintenance costs during the whole life cycle include:

_Cope = k _r C _m P,

In the formula, _Cope represents the operation and maintenance cost during the whole life cycle, _kr represents the calculation coefficient of the whole life cycle, and _Cm represents the annual operation and maintenance cost per unit charging and discharging power of shared energy storage.

The residual value of a shared energy storage power station can be evaluated by the initial investment cost and the ratio of the residual value of the power station to the initial investment. The evaluation methods include:

C _Rec = C _inv × K _Rec ,

Where C _Rec represents the residual value of the shared energy storage power station, and K _Rec represents the ratio of the residual value of the power station to the initial investment.

The agreed conditions of the equation include: system balance constraints, energy storage charge state continuity constraints, and energy storage initial and final charge state consistency constraints.

System balance constraints include:

P _grid (t)=P _ch (t)+P _load (t)-P _dis (t),

Where P _grid (t) represents the power supply of the grid during period t, P _dis (t) represents the power discharged from the shared energy storage to the distribution network during period t, P _ch (t) represents the power charged by the shared energy storage to the distribution network during period t, and P _load (t) represents the power load of the distribution network during period t.

Energy storage state of charge continuity constraints include:

Where, S _soc,t+1 represents the state of charge of the energy storage at time t+1, S _soc,t represents the state of charge of the energy storage at time t, that is, the state of the system at time t+1 is related to the charge and discharge state at time t; η _c and η _d represent the energy storage charge and discharge efficiency respectively, E represents the rated capacity of the shared energy storage, and Δt represents the state duration at time t;

The energy storage charge state consistency constraints include:

S _soc (1) = S _soc (T),

Where S _soc (1) represents the initial state of charge of the energy storage, and T represents the total number of time periods in a charge and discharge cycle.

Inequality constraints include: energy storage charge/discharge state constraints, energy storage charge/discharge power constraints, and energy storage charge state constraints;

Energy storage charge/discharge state constraints include:

S _dis,t +S _ch,t ≤1,

Wherein, Sch _,t and Sdis _,t represent the actual charging and discharging states of the energy storage at time t, respectively, and are 0-1 variables, where 1 represents the charging state and 0 represents the discharging state.

Energy storage charging/discharging power constraints include:

Wherein, P _dis represents the energy storage discharging power, and P _ch represents the energy storage charging power.

The upper and lower limit constraints of energy storage charge state include:

0.1E _m ＝S _min ≤S _soc ≤S _max ＝0.9E _m

Wherein, _Em represents the storage capacity of the energy storage power station, _Smin and _Smax represent the minimum and maximum values of the energy storage state of charge respectively, and _Ssoc represents the energy storage state of charge.

In this embodiment, the capacity configuration of the shared energy storage system is optimized, the cplex solver is called to solve, and the solution result is output, that is, the energy storage configuration power, capacity, net income within the full life cycle of the shared energy storage, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the benefit of the optimization configuration method and obtain the evaluation result.

Among them, net income includes:

F ₁ =S ₁ +S ₂ +S ₃ -C _inv -C _ope +C _Rec .

The dynamic payback period includes:

In the formula, _Pt represents the dynamic investment payback period, _CIn represents the cash inflow in the nth year, _COn represents the cash outflow in the nth year, and BY represents the benchmark rate of return.

The evaluation criteria are: compare the dynamic investment payback period _Pt with the standard investment payback period _Ps . If _Pt < _Ps , the solution is feasible, and the smaller T is, the better the solution is; otherwise, the solution is not feasible.

The internal rate of return includes:

In the formula, N represents the operating life of the energy storage power station, IRR represents the internal rate of return, and _Cn represents the net cash flow in the nth year.

The evaluation criteria are: compared with the benchmark rate of return BY, if IRR>BY, the project plan is economically feasible; if IRR<BY, the project plan is economically infeasible.

Based on the integrated application scenarios of multiple types of shared energy storage, the shared energy storage backup plan is substituted into the system model to obtain the results. The obtained results are evaluated individually or jointly through the shared energy storage economic evaluation indicators, and the best economic plan is selected based on the evaluation results.

The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims (10)

1. An economic evaluation method of shared energy storage based on the whole life cycle, which is characterized by including the following steps: S1. Determine the energy storage type and determine the system parameters of the energy storage type; S2. Construct a shared energy storage optimization configuration model based on the system parameters, and perform capacity optimization configuration on the energy storage type based on the shared energy storage optimization configuration model; and evaluate the optimization configuration method to obtain evaluation results. . 2. A method for economic evaluation of shared energy storage based on the whole life cycle according to claim 1, characterized in that the energy storage types include: lithium-ion batteries, pumped water energy storage, compressed air energy storage, carbon lead batteries and vanadium flow batteries; The system parameters include: initial investment cost, annual operation and maintenance cost, life, residual value, number of operations, depth of discharge, cycle efficiency and cost of electricity. 3. A method for economic evaluation of shared energy storage based on the whole life cycle according to claim 1, characterized in that the shared energy storage optimal configuration model includes: an objective function and constraints; The objective function adopts the maximum value of net profit, including: the full life cycle investment cost of the shared energy storage power station and the income of the shared energy storage power station; The constraints include: equality constraints and inequality constraints. 4. A method of economic evaluation of shared energy storage based on the whole life cycle according to claim 3, characterized in that the whole life cycle investment cost of the shared energy storage power station includes: initial investment cost, operation and maintenance during the whole life cycle. Cost and residual value of shared energy storage power stations; The initial investment costs include: C _inv =C _p P + C _e E, In the formula, C _inv represents the initial investment cost, C _p represents the unit charge/discharge power cost of shared energy storage, P represents the rated power value of shared energy storage, C _e represents the unit capacity cost of shared energy storage, and E represents the cost of shared energy storage. Rated Capacity; The operation and maintenance costs during the entire life cycle include: C _ope = k _r C _m P, In the formula, C _ope represents the operation and maintenance cost during the whole life cycle, k _r represents the calculation coefficient during the whole life cycle, and C _m represents the annual operation and maintenance cost per unit charge and discharge power of shared energy storage; The residual value of the shared energy storage power station includes: C _Rec = C _inv × K _Rec , In the formula, C _Rec represents the residual value of the shared energy storage power station, and K _Rec represents the ratio of the residual value of the power station to the initial investment. 5. A method for economic evaluation of shared energy storage based on the whole life cycle according to claim 3, characterized in that the agreed conditions of the equation include: system balance constraints, energy storage state of charge continuity constraints and energy storage Consistency constraint on state of charge throughout; The system balance constraints include: P _grid (t)=P _ch (t)+P _load (t)-P _dis (t), In the formula, P _grid (t) represents the grid power supply during t period, P _dis (t) represents the discharge power of shared energy storage to the distribution network during t period, P _ch (t) represents the charging power of shared energy storage to the distribution network during t period, P _load (t) represents the power load of the distribution network during t period; The energy storage state of charge continuity constraints include: In the formula, S _soc,t+1 represents the state of charge of the energy storage at time t+1, S _soc,t represents the state of charge of the energy storage at time t; η _c and η _d represent the charging and discharging efficiency of the energy storage respectively. , E represents the rated capacity of shared energy storage, Δt represents the state duration at time t; The consistency constraints of the state of charge throughout the energy storage include: S _soc (1)=S _soc (T), In the formula, S _soc (1) represents the initial state of charge of the energy storage, and T represents the total number of periods in a charge and discharge cycle. 6. A method for economic evaluation of shared energy storage based on the whole life cycle according to claim 3, characterized in that the inequality constraints include: energy storage charge/discharge state constraints, energy storage charge/discharge power constraints, storage Energy charge state constraints; The energy storage charge/discharge state constraints include: S _dis,t +S _ch,t ≤1, In the formula, S _ch,t and S _dis,t respectively represent the actual charge and discharge state of the energy storage at time t, which are 0-1 variables, where 1 represents the charging state; 0 represents the discharge state; The energy storage charging/discharging power constraints include: In the formula, P _dis represents the energy storage discharge power, and P _ch represents the energy storage charging power; The upper and lower limit constraints of the energy storage state of charge include: 0.1E＝S _min ≤S _soc ≤S _max ＝0.9E In the formula, E represents the rated capacity of the energy storage power station, S _min and S _max represent the minimum and maximum values of the energy storage state of charge respectively, and S _soc represents the energy storage state of charge. 7. A method for economic evaluation of shared energy storage based on the whole life cycle according to claim 3, characterized in that the method for optimizing configuration is evaluated, and the method for obtaining the evaluation result includes: Net income, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the optimal allocation method, and the evaluation results are obtained. 8. An economic evaluation system for shared energy storage based on the whole life cycle, the evaluation system is used to implement the evaluation method according to any one of claims 1 to 7, characterized in that it includes: a first evaluation unit and a third evaluation unit. 2 assessment units; The first evaluation unit is used to determine the energy storage type and determine the system parameters of the energy storage type; The second evaluation unit is configured to construct a shared energy storage optimized configuration model based on the system parameters, and perform capacity optimization configuration on the energy storage type based on the shared energy storage optimized configuration model; and the method for the optimized configuration Conduct an evaluation and obtain the evaluation results. 9. An economic evaluation system for shared energy storage based on the whole life cycle according to claim 8, characterized in that the shared energy storage optimal configuration model includes: an objective function and constraints; The objective function adopts the maximum value of net profit, including: the full life cycle investment cost of the shared energy storage power station and the income of the shared energy storage power station; The constraints include: equality constraints and inequality constraints. 10. A shared energy storage economic evaluation system based on the whole life cycle according to claim 8, characterized in that the method for the second evaluation unit to obtain the evaluation result includes: Net income, dynamic investment payback period and internal rate of return are used as evaluation indicators to evaluate the optimal allocation method, and the evaluation results are obtained.