Energy storage system full life cycle benefit evaluation method

Abstract

The invention discloses a full life cycle benefit evaluation method for an energy storage system, which relates to the technical field of energy storage systems, and specifically comprises the following steps: step 1, based on the income and cost of decisions made by the energy storage system at different time points, determining the change conditions of the return income and input cost of the energy storage system in different time periods, 2, determining the full life cycle of the energy storage system, and predicting the operation state data of the energy storage system in the full life cycle of the energy storage system, and 3, based on the prediction of the operation state data of the energy storage system, integrating the economic benefit and the charge-discharge loss index of the energy storage system, and establishing the comprehensive benefit evaluation index of the energy storage system. According to the method, through establishment and application of the comprehensive benefit evaluation indexes of the energy storage system, powerful support is provided for evaluating economic benefits of the energy storage system, optimizing investment decisions and promoting development of the energy storage industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage systems, and in particular relates to a method for evaluating the benefits of an energy storage system over its entire life cycle. Background Art

[0002] With the global emphasis on environmental protection and sustainable development, renewable energy such as solar energy and wind energy has been vigorously developed. However, renewable energy generation is intermittent and uncertain, which poses a challenge to the stable power supply of the power system. In order to balance the supply and demand relationship and improve the flexibility and stability of the power system, energy storage systems have come into being. By evaluating the benefits of the energy storage system throughout its life cycle, it can be ensured that it can play its maximum role in practical applications, thereby meeting the needs of renewable energy development.

[0003] In recent years, energy storage technology has made significant progress, with the emergence of a variety of technologies, including lithium-ion batteries, hydrogen fuel cells, compressed air energy storage, etc. These technologies have different characteristics and application scenarios, providing more possibilities for the selection and configuration of energy storage systems. However, different energy storage technologies vary in terms of cost, efficiency, life, etc., so it is necessary to comprehensively evaluate the benefits of the energy storage system throughout its life cycle in order to select the most suitable energy storage technology.

[0004] However, current evaluation methods for energy storage systems often only focus on the benefits of a certain stage or aspect of the energy storage system, while ignoring the comprehensive benefits of the energy storage system throughout its entire life cycle. Therefore, it is urgent to propose a benefit evaluation method for the entire life cycle of an energy storage system, which can be used to comprehensively consider the benefit changes of the energy storage system at each stage, the mutual influence and constraint relationship between each link, so as to more comprehensively reflect the comprehensive benefits of the energy storage system and provide strong support for the optimal design and operation of the energy storage system. Summary of the invention

[0005] The purpose of the present invention is to provide a method for evaluating the benefits of an energy storage system throughout its life cycle, so as to solve the technical problem that the prior art ignores the comprehensive benefits of the energy storage system throughout its life cycle.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for evaluating the benefits of an energy storage system throughout its life cycle, comprising:

[0008] Step 1: Based on the revenue and cost of the energy storage system decisions made at different points in time, determine the changes in the return income and investment cost of the energy storage system in different time periods.

[0009] The time length between two adjacent charging time points of the energy storage system is recorded as the energy storage time period, the first charging time point of the energy storage time period is recorded as the starting charging time point, and the second charging time point is recorded as the ending charging time point, and the energy storage system operation status data is collected to determine the return income and investment cost data of the energy storage system during the energy storage time period. The energy storage system operation status data includes: the charging amount, discharging amount, charging electricity price, discharging electricity price, charging efficiency, discharging efficiency and fault data of the energy storage system at each time;

[0010] The return income of the energy storage system in the kth energy storage time period is recorded as ga(k). The specific formula is as follows:

[0011]

[0012] Wherein, i represents the kth discharge time point in energy storage time period k, n(k) represents a total of n(k) discharge time points in energy storage time period k, when there is no discharge behavior of the energy storage system in energy storage time period k, n(k) = 0, fa(i) represents the electricity price at the i-th discharge time point, ma(i) represents the discharge amount at the i-th discharge time point, a(k) represents the income of the energy storage system's auxiliary services in energy storage time period k, and auxiliary services refer to the energy storage system providing peak load and frequency regulation services according to the grid dispatching requirements to obtain corresponding income.

[0013] The investment cost of the energy storage system in the kth energy storage time period is recorded as gb(k). The specific formula is as follows:

[0014] gb(k)=[fb(k)*mb(k)+b(k)]*(1+cb(k));

[0015] fb(k) represents the electricity price at the starting charging time of the kth energy storage time period, mb(k) represents the preset charging amount at the starting charging time of the kth energy storage time period, b(k) represents the additional cost of the energy storage system in the energy storage time period k, and the additional cost refers to the cost of the energy storage system due to equipment component replacement, maintenance investment, and energy storage system construction, and cb(k) represents the energy storage system failure impact index in the energy storage time period k;

[0016] Furthermore, by collecting the fault data of the energy storage system in each time period, the fault operation index of the energy storage system is determined. The fault data includes: the number of faults occurring in the energy storage time period, the time from fault discovery to fault elimination, and the battery capacity that is not storing energy during the fault period. The specific calculation formula of the energy storage system fault impact index is as follows:

[0017]

[0018] Wherein, j represents the jth fault occurring within energy storage time period k, m(k) represents a total of m(k) faults occurring within energy storage time period k, when no fault occurs within energy storage time period k, m(k)=cb(k)=0, t(k) represents the duration of energy storage time period k, D(j) represents the duration from fault discovery to fault elimination of the energy storage system for the jth fault, qb(j) represents the battery capacity that is not stored by the energy storage system during the fault period due to the jth fault, fb(k) represents the electricity price at the starting charging time point of the kth energy storage time period, and mb(k) represents the preset charge capacity at the starting charging time point of the kth energy storage time period.

[0019] Step 2: Determine the entire life cycle of the energy storage system and predict the operating status data of the energy storage system during the entire life cycle of the energy storage system.

[0020] Determine the rated capacity of the energy storage battery of the energy storage system, collect the discharge current data and discharge time data during the discharge process of the energy storage system, calculate the discharge depth of the energy storage battery by the ampere-hour integration method, and determine the maximum number of cycles of the energy storage battery based on the discharge depth of the energy storage battery. The specific calculation formula is as follows:

[0021] r(SD)=a1*SD a2 -a3;

[0022] Wherein, SD represents the discharge depth of the battery, r(SD) represents the maximum number of cycles of the energy storage battery with a discharge depth of SD, and a1, a2, and a3 are constant values;

[0023] The service life of the energy storage battery is determined based on the maximum number of cycles of the energy storage battery. The specific calculation formula is as follows:

[0024]

[0025] Where nx(r) represents the service life of the energy storage battery with a maximum cycle number of r, cs represents the average number of charge and discharge cycles of the energy storage system per day, r represents the maximum cycle number of the energy storage battery, r represents the remaining number of cycles when the energy storage battery is no longer used, and N is a constant. The length of time the energy storage battery can work in the future is determined based on the service life of the energy storage battery, thereby obtaining the full life cycle length of the energy storage system;

[0026] According to the changes in power load of the power grid in different regions and at different times, the CNN-LSTM combined prediction model is used to predict the return income and investment cost of the energy storage system throughout its life cycle. The CNN model is used to accurately extract the characteristic information of the time series data of the energy storage system, improve the accuracy of the LSTM model in predicting the energy storage system, and establish an LSTM network structure including input gate, output gate, forget gate, and state unit. Data is input through the input gate of the LTSM model. The forget gate combines the input data at the current moment with the output data at the previous moment, and uses the sigmoid function to realize the useless data in the input data and forget it. The state unit is used to store the candidate value. The input gate passes the input information through s The igmoid function and the tanh function are used to determine the part of the state unit that needs to be retained. The candidate value of the state unit that needs to be updated in the state unit is determined by multiplying the candidate value of the historical state unit with the output result of the forget gate, and the state update value belonging to the current moment is updated. Finally, the state update value of the state unit is output through the output gate, and then multiplied by the activation function to obtain the output value. The historical investment cost and return income of the energy storage system are input into the CNN-LSTM model as a training set to predict the investment cost and return income of the energy storage system. The charging time point and discharging time point of the energy storage system are input into the CNN-LSTM model as a training set to predict the number of energy storage time periods of the energy storage system.

[0027] Step 3: Based on the prediction of the operating status data of the energy storage system, the economic benefits and charging and discharging loss indicators of the energy storage system are comprehensively considered to establish a comprehensive benefit evaluation index for the energy storage system.

[0028] The economic benefits of the energy storage system are determined based on the investment cost and return income of the energy storage system. The charge and discharge loss index of the energy storage battery is determined based on the number of charge and discharge cycles of the energy storage battery in its entire life cycle. The comprehensive benefit evaluation index of the energy storage system is established by combining the economic benefits of the energy storage system and the charge and discharge loss index of the energy storage battery. The specific calculation formula is as follows:

[0029]

[0030] Wherein, Jd represents the comprehensive benefit evaluation index of the energy storage system, W represents the total number of energy storage time periods of the energy storage system, k represents the kth energy storage time period of the energy storage system, ga(k) represents the return income of the kth energy storage time period of the energy storage system, gb(k) represents the investment cost of the kth energy storage time period of the energy storage system, (ga(k)-gb(k)) represents the economic benefit of the kth time period of the energy storage system, t(k) represents the length of energy storage time period k, CI represents the charge and discharge loss index of the energy storage battery, A1 represents the weight coefficient of the profitability index, e is a constant, and the larger the comprehensive benefit evaluation index of the energy storage system, the better the benefit of the energy storage system.

[0031] Furthermore, the specific calculation formula of the charge and discharge loss index of the energy storage battery is as follows:

[0032]

[0033] Among them, C d Represents the capacity cost of the energy storage battery used in the energy storage system, C p Represents the capacity configuration of the energy storage battery used in the energy storage system, R t Represents the average number of charge and discharge cycles of the energy storage battery in one day, R f Indicates the number of charge and discharge cycles of the energy storage system's energy storage battery during its entire life cycle.

[0034] Based on the historical average economic benefits of the energy storage system, a comprehensive benefit threshold U of the energy storage system is set. When Jd is less than or equal to U, it means that the comprehensive benefit of the energy storage system is poor, and the energy storage battery needs to be updated or the charging and discharging strategy needs to be adjusted. When Jd is greater than U, it means that the comprehensive benefit of the energy storage system is good. By appropriately adjusting the charging and discharging strategy of the energy storage system, the comprehensive benefit evaluation index of the energy storage system can be improved.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. The present invention determines the maximum number of cycles of the energy storage battery based on the depth of discharge, combines the maximum number of cycles of the energy storage battery with the average number of charge and discharge cycles of the energy storage system per day, and considers the number of cycles remaining when the battery ends its use, which helps to improve the accuracy of determining the service life of the energy storage battery and further improve the accuracy of determining the full life cycle length of the energy storage system;

[0037] 2. The present invention determines key parameters of the energy storage system, such as the investment cost, return income, number of battery cycles and life, to achieve prediction and evaluation throughout the life cycle of the energy storage system. By establishing comprehensive benefit evaluation indicators for the energy storage system, the economic benefits of the energy storage system are comprehensively evaluated, which helps to reduce investment risks and improve the rate of return on investment. The comprehensive benefit evaluation indicators for the energy storage system also reflect the performance of the energy storage system throughout its life cycle, providing guidance for the energy storage system to adjust system parameters and optimize operation strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 work.

[0039] Figure 1A diagram showing the steps of a benefit evaluation method for the entire life cycle of an energy storage system is shown;

[0040] Figure 2 A method step diagram for establishing comprehensive benefit evaluation indicators for energy storage systems is shown. DETAILED DESCRIPTION

[0041] 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.

[0042] like Figure 1 , Figure 2 A benefit evaluation method for the entire life cycle of an energy storage system is shown, which specifically includes the following steps:

[0043] Step 1: Based on the revenue and cost of the energy storage system decisions made at different points in time, determine the changes in the return income and investment cost of the energy storage system in different time periods.

[0044] The time length between two adjacent charging time points of the energy storage system is recorded as the energy storage time period, the first charging time point of the energy storage time period is recorded as the starting charging time point, and the second charging time point is recorded as the ending charging time point, and the energy storage system operation status data is collected to determine the return income and investment cost data of the energy storage system during the energy storage time period. The energy storage system operation status data includes: the charging amount, discharging amount, charging electricity price, discharging electricity price, charging efficiency, discharging efficiency and fault data of the energy storage system at each time;

[0045] The return income of the energy storage system in the kth energy storage time period is recorded as ga(k). The specific formula is as follows:

[0046]

[0047] Wherein, i represents the kth discharge time point in energy storage time period k, n(k) represents a total of n(k) discharge time points in energy storage time period k, when there is no discharge behavior of the energy storage system in energy storage time period k, n(k) = 0, fa(i) represents the electricity price at the i-th discharge time point, ma(i) represents the discharge amount at the i-th discharge time point, a(k) represents the income of the energy storage system's auxiliary services in energy storage time period k, and auxiliary services refer to the energy storage system providing peak load and frequency regulation services according to the grid dispatching requirements to obtain corresponding income.

[0048] The investment cost of the energy storage system in the kth energy storage time period is recorded as gb(k). The specific formula is as follows:

[0049] gb(k)=[fb(k)*mb(k)+b(k)]*(1+cb(k));

[0050] fb(k) represents the electricity price at the starting charging time of the kth energy storage time period, mb(k) represents the preset charging amount at the starting charging time of the kth energy storage time period, b(k) represents the additional cost of the energy storage system in the energy storage time period k, and the additional cost refers to the cost of the energy storage system due to equipment component replacement, maintenance investment, and energy storage system construction, and cb(k) represents the energy storage system failure impact index in the energy storage time period k;

[0051] Furthermore, by collecting the fault data of the energy storage system in each time period, the fault operation index of the energy storage system is determined. The fault data includes: the number of faults occurring in the energy storage time period, the time from fault discovery to fault elimination, and the battery capacity that is not storing energy during the fault period. The specific calculation formula of the energy storage system fault impact index is as follows:

[0052]

[0053] Wherein, j represents the jth fault occurring within energy storage time period k, m(k) represents a total of m(k) faults occurring within energy storage time period k, when no fault occurs within energy storage time period k, m(k)=cb(k)=0, t(k) represents the duration of energy storage time period k, D(j) represents the duration from fault discovery to fault elimination of the energy storage system for the jth fault, qb(j) represents the battery capacity that is not stored by the energy storage system during the fault period due to the jth fault, fb(k) represents the electricity price at the starting charging time point of the kth energy storage time period, and mb(k) represents the preset charge capacity at the starting charging time point of the kth energy storage time period.

[0054] Step 2: Determine the entire life cycle of the energy storage system and predict the operating status data of the energy storage system during the entire life cycle of the energy storage system.

[0055] Determine the rated capacity of the energy storage battery of the energy storage system, collect the discharge current data and discharge time data during the discharge process of the energy storage system, calculate the discharge depth of the energy storage battery by the ampere-hour integration method, and determine the maximum number of cycles of the energy storage battery based on the discharge depth of the energy storage battery. The specific calculation formula is as follows:

[0056] r(SD)=a1*SD a2 -a3;

[0057] Wherein, SD represents the discharge depth of the battery, r(SD) represents the maximum number of cycles of the energy storage battery with a discharge depth of SD, a1, a2, and a3 are constant values. In this embodiment, a1=6380, a2=-0.3610, and a3=1688 are set;

[0058] The service life of the energy storage battery is determined based on the maximum number of cycles of the energy storage battery. The specific calculation formula is as follows:

[0059]

[0060] Wherein, nx(r) represents the service life of the energy storage battery with a maximum cycle number of r, cs represents the average number of charge and discharge cycles of the energy storage system per day, r represents the maximum cycle number of the energy storage battery, r represents the remaining number of cycles when the energy storage battery is no longer used, and N is a constant. In this embodiment, N=365. The length of time that the energy storage battery can work in the future is determined based on the service life of the energy storage battery, thereby obtaining the full life cycle length of the energy storage system;

[0061] According to the changes in power load of the power grid in different regions and at different times, the CNN-LSTM combined prediction model is used to predict the return income and investment cost of the energy storage system throughout its life cycle. The CNN model is used to accurately extract the characteristic information of the time series data of the energy storage system, improve the accuracy of the LSTM model in predicting the energy storage system, and establish an LSTM network structure including input gate, output gate, forget gate, and state unit. Data is input through the input gate of the LTSM model. The forget gate combines the input data at the current moment with the output data at the previous moment, and uses the sigmoid function to realize the useless data in the input data and forget it. The state unit is used to store the candidate value. The input gate passes the input information through s The igmoid function and the tanh function are used to determine the part of the state unit that needs to be retained. The candidate value of the state unit that needs to be updated in the state unit is determined by multiplying the candidate value of the historical state unit with the output result of the forget gate, and the state update value belonging to the current moment is updated. Finally, the state update value of the state unit is output through the output gate, and then multiplied by the activation function to obtain the output value. The historical investment cost and return income of the energy storage system are input into the CNN-LSTM model as a training set to predict the investment cost and return income of the energy storage system. The charging time point and discharging time point of the energy storage system are input into the CNN-LSTM model as a training set to predict the number of energy storage time periods of the energy storage system.

[0062] Step 3: Based on the prediction of the operating status data of the energy storage system, the economic benefits and charging and discharging loss indicators of the energy storage system are comprehensively considered to establish a comprehensive benefit evaluation index for the energy storage system.

[0063] The economic benefits of the energy storage system are determined based on the investment cost and return income of the energy storage system. The charge and discharge loss index of the energy storage battery is determined based on the number of charge and discharge cycles of the energy storage battery in its entire life cycle. The comprehensive benefit evaluation index of the energy storage system is established by combining the economic benefits of the energy storage system and the charge and discharge loss index of the energy storage battery. The specific calculation formula is as follows:

[0064]

[0065] Wherein, Jd represents the comprehensive benefit evaluation index of the energy storage system, W represents the total number of energy storage time periods of the energy storage system, k represents the kth energy storage time period of the energy storage system, ga(k) represents the return income of the kth energy storage time period of the energy storage system, gb(k) represents the investment cost of the kth energy storage time period of the energy storage system, (ga(k)-gb(k)) represents the economic benefit of the kth time period of the energy storage system, t(k) represents the length of the energy storage time period k, CI represents the charge and discharge loss index of the energy storage battery, A1 represents the weight coefficient of the profitability index, and e is a constant. In this embodiment, e=2.7. The larger the comprehensive benefit evaluation index of the energy storage system, the better the benefit of the energy storage system.

[0066] Furthermore, the specific calculation formula of the charge and discharge loss index of the energy storage battery is as follows:

[0067]

[0068] Among them, C d Represents the capacity cost of the energy storage battery used in the energy storage system, C p Represents the capacity configuration of the energy storage battery used in the energy storage system, R t Represents the average number of charge and discharge cycles of the energy storage battery in one day, R f Indicates the number of charge and discharge cycles of the energy storage system's energy storage battery during its entire life cycle.

[0069] Based on the historical average economic benefits of the energy storage system, a comprehensive benefit threshold U of the energy storage system is set. When Jd is less than or equal to U, it means that the comprehensive benefit of the energy storage system is poor, and the energy storage battery needs to be updated or the charging and discharging strategy needs to be adjusted. When Jd is greater than U, it means that the comprehensive benefit of the energy storage system is good. By appropriately adjusting the charging and discharging strategy of the energy storage system, the comprehensive benefit evaluation index of the energy storage system can be improved.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0071] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for evaluating the benefits of an energy storage system over its entire life cycle, characterized in that: include: Step 1: Based on the revenue and cost of the energy storage system at different time points, determine the changes in the return income and input cost of the energy storage system in different time periods; The time length between two adjacent charging time points of the energy storage system is recorded as the energy storage time period, the first charging time point of the energy storage time period is recorded as the starting charging time point, and the second charging time point is recorded as the ending charging time point, and the operating status data of the energy storage system is collected; The energy storage system operation status data includes: the energy storage system's charge capacity, discharge capacity, charging electricity price, discharge electricity price, charging efficiency, discharge efficiency and fault data at each moment; Step 2: Determine the entire life cycle of the energy storage system and predict the operating status data of the energy storage system within the entire life cycle of the energy storage system; Step 3: Based on the prediction of the operating status data of the energy storage system, the economic benefits and charging and discharging loss indicators of the energy storage system are comprehensively considered to establish a comprehensive benefit evaluation index for the energy storage system.

2. The method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 1, characterized in that: Determine the changes in the return income of the energy storage system in different time periods. The specific method is as follows: Using the formula It represents the return income of the energy storage system in the kth energy storage time period, where i represents the kth discharge time point in the energy storage time period k, n(k) represents the total number of n(k) discharge time points in the energy storage time period k, and when there is no discharge behavior of the energy storage system in the energy storage time period k, n(k) = 0, fa(i) represents the electricity price at the i-th discharge time point, ma(i) represents the discharge amount at the i-th discharge time point, and a(k) represents the income of the energy storage system's auxiliary services in the energy storage time period k. Auxiliary services refer to the energy storage system providing peak load and frequency regulation services according to the grid dispatching needs to obtain corresponding income.

3. The method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 1, characterized in that: Determine the changes in the investment cost of the energy storage system in different time periods. The specific method is as follows: The formula gb(k)=[fb(k)*mb(k)+b(k)]*(1+cb(k)) is used to represent the investment cost of the energy storage system in the kth energy storage time period, fb(k) represents the electricity price at the starting charging time point of the kth energy storage time period, mb(k) represents the preset charging amount at the starting charging time point of the kth energy storage time period, b(k) represents the additional cost of the energy storage system in the energy storage time period k, and the additional cost refers to the cost incurred by the energy storage system due to equipment component replacement, maintenance investment, and energy storage system construction, and cb(k) represents the energy storage system failure impact index in the energy storage time period k.

4. A method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 3, characterized in that: Energy storage system failure impact indicators within energy storage time period k, including: By collecting the fault data of the energy storage system in each time period, the fault operation index of the energy storage system is determined. The fault data includes: the number of faults occurring in the energy storage time period, the time from fault discovery to fault elimination, and the battery capacity that is not stored during the fault period; Using the formula It represents the energy storage system fault impact index of the kth energy storage time period of the energy storage system, wherein j represents the jth fault occurring in the energy storage time period k, m(k) represents a total of m(k) faults occurring in the energy storage time period k, when no fault occurs in the energy storage time period k, m(k)=cb(k)=0, t(k) represents the duration of the energy storage time period k, D(j) represents the duration from fault discovery to fault elimination of the energy storage system with the jth fault, qb(j) represents the battery capacity that is not stored by the energy storage system during the fault period due to the jth fault, fb(k) represents the electricity price at the starting charging time point of the kth energy storage time period, and mb(k) represents the preset charge capacity at the starting charging time point of the kth energy storage time period.

5. The method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 1, characterized in that: Determine the full life cycle of the energy storage system. The specific method is: Using the formula Represents the service life of the energy storage battery, where nx(r) represents the service life of the energy storage battery with a maximum cycle number of r, cs represents the average number of charge and discharge cycles of the energy storage system per day, and r represents the maximum cycle number of the energy storage battery. It indicates the number of cycles remaining when the energy storage battery ends its use. N is a constant. Based on the service life of the energy storage battery, the length of time the energy storage battery can work in the future is determined to obtain the full life cycle length of the energy storage system.

6. A method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 5, characterized in that: The maximum number of cycles of energy storage batteries, including: Determine the rated capacity of the energy storage battery of the energy storage system, collect the discharge current data and discharge time data during the discharge process of the energy storage system, calculate the discharge depth of the energy storage battery by the ampere-hour integration method, and use the formula r(SD)=a1*SD a2 -a3 represents the maximum number of cycles of the energy storage battery, where SD represents the discharge depth of the battery, r(SD) represents the maximum number of cycles of the energy storage battery with a discharge depth of SD, and a1, a2, and a3 are constant values.

7. The method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 1, characterized in that: The comprehensive benefit evaluation index of the energy storage system is established by integrating the economic benefits and charging and discharging loss indicators of the energy storage system. The specific method is as follows: Using the formula represents the comprehensive benefit evaluation index of the energy storage system, where W represents the total number of energy storage time periods of the energy storage system, k represents the kth energy storage time period of the energy storage system, ga(k) represents the return income of the kth energy storage time period of the energy storage system, gb(k) represents the investment cost of the kth energy storage time period of the energy storage system, (ga(k)-gb(k)) represents the economic benefit of the kth time period of the energy storage system, t(k) represents the length of energy storage time period k, CI represents the charge and discharge loss index of the energy storage battery, A1 represents the weight coefficient of the profitability index, and e is a constant.

8. The method for evaluating the benefits of an energy storage system throughout its life cycle according to claim 7, characterized in that: The charging and discharging loss indicators of energy storage batteries include: Using the formula represents the charge and discharge loss index of the energy storage battery in the kth energy storage time period, where C d Represents the capacity cost of the energy storage battery used in the energy storage system, C p Represents the capacity configuration of the energy storage battery used in the energy storage system, R t Represents the average number of charge and discharge cycles of the energy storage battery in one day, R f Indicates the number of charge and discharge cycles of the energy storage system's energy storage battery during its entire life cycle.

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