Method and Device for Determining Grade of Energy Storage Station Based on Index Evaluation System

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present disclosure claims the priority to the Chinese patent application with the filing No. 202310527757.5 filed with the Chinese Patent Office on May 9, 2023, and entitled “Method and Device for Determining Grade of Energy Storage Station Based on Index Evaluation System”, the contents of which are incorporated herein by reference in entirety.

TECHNICAL FIELD

The present disclosure relates to the field of energy storage station management, and specifically to a method and a device for determining the grade of an energy storage station based on an index evaluation system

BACKGROUND ART

With the development of science and technology and the increasing demand for electric power, energy storage stations are becoming increasingly important in supporting the construction of a new power system dominated by new energy. Energy storage stations play a significant role in actively supporting the power system in areas such as ancillary frequency regulation, power fluctuation suppression, and voltage control. Additionally, the participation of energy storage stations in the new power system can facilitate the power generation and absorption of new energy.

Energy storage stations, as an indispensable part of the power system, require a grade assessment to ensure the normal operation of the power system. This provides information about the status of the energy storage station based on the results of the evaluation grade obtained after the evaluation, thus enabling subsequent control of both the energy storage station and the power system according to the state of the energy storage station.

In prior art, when assessing the grade of energy storage stations, the evaluation grade of the energy storage station is typically determined by relevant personnel based on historical experience using operational data from each energy storage station. However, when determining the evaluation grade of energy storage stations through the above-mentioned method, there is a potential risk of errors in the evaluation grade determined due to insufficient experience of relevant personnel, thereby reducing the accuracy of the obtained evaluation grade. Additionally, since it is necessary to determine the evaluation grade for each energy storage station, the involvement of relevant personnel in every assessment process can significantly increase the human labor costs required for determining the evaluation grade of energy storage stations.

SUMMARY

In view of the above, the objective of the present disclosure is to provide a method and a device for determining the grade of an energy storage station based on an index evaluation system. Therefore, the accuracy of the obtained evaluation grade of the energy storage station is enhanced, concurrently reducing the human labor costs required for determining the evaluation grade of the energy storage station.

In the first aspect, the embodiments of the present disclosure provide a method for determining the grade of an energy storage station based on an index evaluation system, wherein the method comprises

- obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station;
- utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station;
- utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station;
- determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station; and
- utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station.

Optionally, the at least one evaluation indicator comprises

- a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.

Optionally, the step of obtaining an indicator score of at least one evaluation indicator of the energy storage station comprises

- determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station;
- determining an indicator score of the energy efficiency level based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station;
- determining an indicator score of the failure frequency based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station;
- determining an indicator score of the power control based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station;
- determining an indicator score of the peak-shaving and valley-filling capability of a system based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station;
- determining an indicator score of the system frequency regulation based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station;
- determining an indicator score of the reactive power support based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station;
- determining an indicator score of the response success rate based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station;
- determining an indicator score of the equivalent utilization coefficient based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station;
- determining an indicator score of the outage coefficient based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the availability coefficient based on an available time of the energy storage station within the evaluation period and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the frequency proactive support capability based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of the system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located;
- determining an indicator score of the voltage proactive support capability based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at regional power grid boundary nodes for which the energy storage station participates in regulation;
- determining an indicator score of the transient stability support capability based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during transient processes, a frequency deviation at the grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station;
- determining an indicator score of the cost per unit of electricity based on a total cost of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period;
- determining an indicator score of the net present value based on the revenue of the energy storage station within the evaluation period, a cost and a discount rate of the energy storage station within the evaluation period;
- determining an indicator score of the return on investment based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station;
- determining an indicator score of the carbon emission reduction based on a carbon emission coefficient and a released renewable energy amount of the energy storage station;
- determining an indicator score of the effective emission reduction rate based on a clean energy generation amount of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period; and
- determining an indicator score of the clean energy absorption rate based on a clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.

Optionally, the objective weighting method is the CRITIC weighting method.

Optionally, the step of determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station comprises

- establishing an objective function based on the minimum discrimination information principle for determining the comprehensive weight; and
- utilizing the objective function to determine a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

In the second aspect, the embodiments of the present disclosure provide a device for determining the grade of an energy storage station based on an index evaluation system, wherein the device comprises

- an indicator score acquisition module, configured for obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station;
- an objective weight determination module, configured for utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station;
- a subjective weight determination module, configured for utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station;
- a comprehensive weight determination module, configured for determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station; and
- an evaluation grade determination module, configured for utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station.

Optionally, the at least one evaluation indicator comprises

- a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.

Optionally, the indicator score acquisition module is configured for obtaining an indicator score of at least one evaluation indicator of the energy storage station, which is specifically configured for

- determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station;
- determining an indicator score of the energy efficiency level based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station;
- determining an indicator score of the failure frequency based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station;
- determining an indicator score of the power control based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station;
- determining an indicator score of the peak-shaving and valley-filling capability of a system based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station;
- determining an indicator score of the system frequency regulation based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station;
- determining an indicator score of the reactive power support based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station;
- determining an indicator score of the response success rate based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station;
- determining an indicator score of the equivalent utilization coefficient based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station;
- determining an indicator score of the outage coefficient based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the availability coefficient based on an available time of the energy storage station within the evaluation period and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the frequency proactive support capability based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of the system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located;
- determining an indicator score of the voltage proactive support capability based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at regional power grid boundary nodes for which the energy storage station participates in regulation;
- determining an indicator score of the transient stability support capability based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during transient processes, a frequency deviation at the grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station;
- determining an indicator score of the cost per unit of electricity based on a total cost of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period;
- determining an indicator score of the net present value based on the revenue of the energy storage station within the evaluation period, a cost and a discount rate of the energy storage station within the evaluation period;
- determining an indicator score of the return on investment based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station;
- determining an indicator score of the carbon emission reduction based on a carbon emission coefficient and a released renewable energy amount of the energy storage station;
- determining an indicator score of the effective emission reduction rate based on a clean energy generation amount of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period; and
- determining an indicator score of the clean energy absorption rate based on a clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.

Optionally, the objective weighting method is the CRITIC weighting method.

Optionally, the comprehensive weight determination module is configured for determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station, which is specifically configured for

- establishing an objective function based on the minimum discrimination information principle for determining the comprehensive weight; and
- utilizing the objective function to determine a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

The technical solution provided in the present disclosure includes but is not limited to the following advantageous effects.

By the above-mentioned step of obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station, it is possible to obtain the indicator scores of the evaluation indicators of each energy storage station based on different assessment dimensions.

By the above-mentioned step of utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station, and the step of utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station, it is possible to determine the objective weight and subjective weight of each evaluation indicator of the energy storage station.

By the above-mentioned step of determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station and the step of utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station, it is possible to determine the evaluation grade of each energy storage station based on the objective weight and subjective weight of each evaluation indicator of the energy storage station.

By employing the aforementioned method, it is possible to determine the weight values of each evaluation indicator based on the indicator scores of each energy storage station across different evaluation indicators. Subsequently, using the weight values of each evaluation indicator of different energy storage stations, the evaluation grade of each energy storage station is determined. This avoids the involvement of relevant personnel and the interference of subjective experience, thus facilitating the determination of evaluation grades of the energy storage stations. At the same time, the accuracy of obtaining the evaluation grade of the energy storage station is enhanced, concurrently reducing the human labor costs required for determining the evaluation grade of the energy storage station.

To make the above objectives, features, and advantages of the present disclosure more evident and comprehensible, the following preferred embodiments are described in detail with the drawings.

BRIEF DESCRIPTION OF DRAWINGS

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore they should not be regarded as a limitation on the scope. Those ordinary skilled in the art can also obtain other related drawings based on these drawings without inventive effort.

FIG. 1 illustrates a flowchart of a method for determining the grade of an energy storage station based on an index evaluation system provided in one embodiment of the present disclosure;

FIG. 2 illustrates a flowchart of the method for determining a comprehensive weight provided in one embodiment of the present disclosure; and

FIG. 3 illustrates a schematic structural diagram of a device for determining the grade of an energy storage station based on an index evaluation system provided in another embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

In order to make the objective, technical solution, and advantages of the present disclosure clearer, the following will provide a clear and complete description of the technical solution in the embodiments of the present disclosure, in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all embodiments. The components of embodiments of the present disclosure which are generally described and illustrated in the drawings herein can be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the claimed disclosure but merely represents selected embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without making inventive efforts are within the scope of protection of the present disclosure.

Embodiment 1

For the objective of facilitating an understanding of the present disclosure, one embodiment of the present disclosure is described in detail below in conjunction with the contents of the description of the flowchart of a method for determining the grade of an energy storage station based on an index evaluation system provided in one embodiment of the present disclosure illustrated in FIG. 1.

Referring to FIG. 1, FIG. 1 illustrates a flowchart of a method for determining the grade of an energy storage station based on an index evaluation system provided in one embodiment of the present disclosure, wherein the method includes the following steps S101 to S105.

S101: obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station.

Specifically, each energy storage station has the same at least one evaluation indicator, and these evaluation indicators are included in a multi-scenario and multi-dimensional indicator evaluation system of the energy storage station, which is configured based on the station status and parameters of the energy storage station across multiple scenarios and dimensions.

The multi-scenario and multi-dimensional indicator evaluation system of the energy storage station divides the evaluation indicators into two levels. The first level includes a performance indicator, an application scenario indicator, an operational reliability indicator, a proactive support capability indicator, an economic indicator, and an environmental protection indicator. Each indicator in the first level has its own second-level indicator.

When the quantity of at least one energy storage station is n, and each energy storage station includes m evaluation indicators, for the j-th evaluation indicator of the i-th energy storage station, where n, m, i, and j are all non-zero natural numbers, with 1≤i≤n and 1≤j≤m, the subsequent steps S102 to S105 are performed.

S102: utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station.

Specifically, the step of utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station includes

- standardizing the j-th evaluation indicator of the i-th energy storage station. Each evaluation indicator is categorized as a positive indicator or a negative indicator based on the positivity or negativity of its indicator score. When the indicator score of an evaluation indicator is positive, the evaluation indicator is determined to be a positive indicator; when the indicator score of the evaluation indicator is negative, the evaluation indicator is determined to be a negative indicator.

When the j-th evaluation indicator of the i-th energy storage station is a positive indicator, its indicator score x_ijis determined using the following expression:

$x_{i j} = \frac{x_{ij}^{'} - \min {x_{ij}^{'}}}{\max {x_{ij}^{'}} - \min {x_{ij}^{'}}} .$

When the j-th evaluation indicator of the i-th energy storage station is a negative indicator, its indicator score x_ijis determined using the following expression:

$x_{i j} = \frac{\max {x_{ij}^{'}} - x_{ij}^{'}}{\max {x_{ij}^{'}} - \min {x_{ij}^{'}}},$

where x′_ijis the indicator score of the j-th evaluation indicator for the i-th energy storage station, min{x′_ij} is the minimum standard value for the indicator score of the j-th evaluation indicator for the i-th energy storage station, and max{x′_ij} is the maximum standard value for the indicator score of the j-th evaluation indicator for the i-th energy storage station.

The standardized indicator evaluation matrix X is determined based on the indicator scores for each evaluation indicator included in each energy storage station:

$X = [\begin{matrix} x_{1 1} & x_{1 2} & \dots & x_{1 m} \\ x_{2 1} & x_{2 2} & \dots & x_{2 m} \\ \dots & \dots & \dots & \dots \\ x_{n 1} & x_{n 2} & \dots & x_{n m} \end{matrix}] .$

The coefficient of variation v_jand correlation coefficient r_ijis calculated based on the indicator evaluation matrix X:

$\begin{matrix} v_{j} = \frac{s_{j}}{\overline{x_{j}}}, \\ r_{i j} = \frac{cov (X_{i}, X_{j})}{s_{i} s_{j}}, \end{matrix}$

where s_jis the standard deviation of the j-th evaluation indicator in the standardized evaluation matrix X, s_iis the standard deviation of the i-th evaluation indicator in the standardized evaluation matrix X, x_j is the mean of the j-th evaluation indicator, and cov(X_i, X_j) is the covariance between the i-th evaluation indicator and the j-th evaluation indicator of the standardized evaluation matrix X.

The information content c_jof the evaluation indicators is determined based on the coefficient of variation and correlation coefficient. The information content of evaluation indicators includes the contrast intensity and conflict intensity between indicators:

$c_{j} = v_{j} \sum_{i = 1}^{m} (1 - r_{ij}),$

where j=1, 2, . . . , m.

The objective weight w_j^Aof the j-th evaluation indicator is determined based on the information content of the evaluation indicators c_j:

$w_{j}^{A} = \frac{c_{j}}{\sum_{m} c_{j}};$

where the greater the information content c_jof the evaluation indicator is, the more information the evaluation indicator includes, indicating stronger relative importance.

S103: utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station.

Specifically, the step of utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station includes

- constructing a direct influence matrix based on the interrelationships of the j-th evaluation indicator of the i-th energy storage station, wherein i and j are considered as two elements in the mixed decision-making model, thus resulting in the direct influence matrix O:

$O = {[o_{ij}]}_{mm},$

where o_ijrepresents the influence of element i on element j, o_ij=0, 1, 2, 3, or 4, and m is the number of evaluation indicators included in each energy storage station.

The normalized matrix D is determined based on the direct influence matrix O:

$D = \frac{O}{\max {\max \sum_{j = 1}^{m} o_{ij}, \max \sum_{i = 1}^{m} o_{i j}}} .$

The comprehensive influence relationship matrix T is determined based on the normalized matrix D:

$T = D \times {(I - D)}^{- 1} .$

The column elements of the comprehensive influence relationship matrix T are normalized to obtain the weighted hypermatrix W^t.

The limit hypermatrix W_DAis determined and provided based on the weighted hypermatrix W^t:

$W_{D A} = \lim_{t \to \infty} W^{t},$

where, if the limit value converges and is unique, and at the same time, the column values of W_DAare the same and the sum of the columns is 1, then the subjective weight w_j^Sof the j-th evaluation indicator is:

$w_{j}^{S} = W_{D A} .$

S104: determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

Specifically, the step of determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station includes

- establishing an objective function based on the minimum discrimination information principle for determining the comprehensive weight; and
- utilizing the objective function to determine a comprehensive weight w_jof the j-th evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

S105: utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station.

Specifically, the step of utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station includes

- determining, based on the comprehensive weight w_jof each evaluation indicator of each energy storage station and the standardized indicator evaluation matrix X, the weighted evaluation matrix Z of the energy storage stations:

$Z = [\begin{matrix} x_{1 1} & x_{1 2} & \dots & x_{1 m} \\ x_{2 1} & x_{2 2} & \dots & x_{2 m} \\ \dots & \dots & \dots & \dots \\ x_{n 1} & x_{n 2} & \dots & x_{n m} \end{matrix}] [\begin{matrix} w_{1} & 0 & 0 & 0 \\ 0 & w_{2} & 0 & 0 \\ 0 & 0 & \dots & 0 \\ 0 & 0 & w_{m} \end{matrix}] = [\begin{matrix} z_{1 1} & z_{1 2} & \dots & z_{1 m} \\ z_{2 1} & z_{2 2} & \dots & z_{2 m} \\ \dots & \dots & \dots & \dots \\ z_{n 1} & z_{n 2} & \dots & z_{n m} \end{matrix}],$

where 1≤j≤m, j is a natural number, n is the number of energy storage stations, and m is the number of evaluation indicators.

The positive ideal solution Z_j⁺ and negative ideal solution Z_j⁻ are calculated for the j-th evaluation indicator of the i-th energy storage station:

${\begin{matrix} Z_{j}^{+} = \max_{1 \leq i \leq n} {z_{i j}}, j = 1, 2, \dots, m \\ Z_{j}^{-} = \min_{1 \leq i \leq n} {z_{i j}}, j = 1, 2, \dots, m \end{matrix},$

where z_ijrepresents the element value in the i-th row and j-th column of the weighted evaluation matrix Z.

Based on the positive ideal solution Z_j⁺ and negative ideal solution Z_j⁻ of the j-th evaluation indicator of the i-th energy storage station, the positive relative distance Z_di⁺ and negative relative distance Z_di⁻ are determined for the j-th evaluation indicator of the i-th energy storage station:

$\begin{matrix} Z_{d i}^{+} = \sqrt{\sum_{j = 1}^{m} {(Z_{j}^{+} - z_{i j})}^{2}}, i = 1, 2, \dots, n; \\ Z_{d i}^{-} = \sqrt{\sum_{j = 1}^{m} {(Z_{j}^{-} - z_{i j})}^{2}}, i = 1, 2, \dots, n . \end{matrix}$

Based on the positive relative distance Z_di⁺ and negative relative distance Z_di⁻ of the j-th evaluation indicator of the i-th energy storage station, the proximity degree H_iof the i-th energy storage station is determined:

$H_{i} = \frac{Z_{d i}^{-}}{Z_{d i}^{-} + Z_{d i}^{+}}, i = 1, 2, \dots, n .$

According to the order of the proximity degree values from large to small, n energy storage stations are sorted. The larger H_iof the energy storage station is, the closer the energy storage station is to the positive ideal solution, the better the comprehensive evaluation result of the energy storage station is, and the higher the evaluation grade of the energy storage station is.

For each energy storage station, based on the proximity degree value of the energy storage station, an evaluation grade having a mapping relationship with the proximity degree value of the energy storage station is determined, from a preset table of evaluation grades, to be the evaluation grade of the energy storage station. The proximity degree value of the energy storage station is positively correlated with the evaluation grade of the energy storage station.

In one feasible embodiment, the at least one evaluation indicator includes

- a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.

In the multi-scenario and multi-dimensional indicator evaluation system of the energy storage station, each indicator in the first level includes its own second-level indicators. The performance indicators include a charge and discharge capacity, an energy efficiency level, and a failure frequency; the application scenario indicators include a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, and a reactive power support; the operational reliability indicators include a response success rate, an equivalent utilization coefficient, an outage coefficient, and an availability coefficient; the active support capability indicators include a frequency proactive support capability, a voltage proactive support capability, and a transient stability support capability; the economic indicators include a cost per unit of electricity, a net present value, and a return on investment; and the environmental protection indicators include a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.

In one feasible embodiment, the step of obtaining an indicator score of at least one evaluation indicator of the energy storage station includes

- determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station.

Specifically, the indicator score α₁of the charge and discharge capacity is determined based on the following expression:

$\begin{matrix} α_{1} = λ_{1} ω_{1} + λ_{2} ω_{2}, \\ ω_{1} = \frac{P_{A D C}}{P_{N}}, \\ ω_{2} = \frac{E_{A D C}}{E_{N}}, \end{matrix}$

where λ₁is the first predefined indicator weight, λ₂is the second predefined indicator weight, ω₁is the actual dischargeable power ratio of the energy storage station, ω₂is the actual dischargeable capacity ratio of the energy storage station, P_ADCis the actual dischargeable power of the energy storage station, P_Nis the rated power of the energy storage station, E_ADCis the actual dischargeable capacity of the energy storage station, and E_Nis the rated energy of the energy storage station.

An indicator score of the energy efficiency level is determined based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station.

Specifically, the energy efficiency level indicator α₂is determined based on the following expression:

$\begin{matrix} α_{2} = λ_{3} ω_{3} + λ_{4} ω_{4} + λ_{5} ω_{5}, \\ ω_{3} = \frac{E_{U P}}{E_{D O W N}}, \\ ω_{4} = \frac{E_{C}}{E_{D}}, \\ ω_{5} = \frac{E_{S E}}{E_{D O W N}}, \end{matrix}$

where λ₃is the third predefined indicator weight, λ₄is the fourth predefined indicator weight, λ₅is the fifth predefined indicator weight, ω₃is the overall efficiency of the energy storage station, ω₄is the energy storage loss rate of the energy storage station, ω₅is the self-consumption rate of the energy storage station, E_UPis the on-grid electricity of the energy storage station, E_DOWNis the off-grid electricity of the energy storage station, E_Cis the total charging amount of the energy storage station, E_Dis the total discharging amount of the energy storage station, and E_SEis the self-consumption electricity of the energy storage station.

An indicator score of the failure frequency is determined based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station.

Specifically, the failure frequency indicator α₃is determined based on the following expression:

$\begin{matrix} α_{3} = λ_{6} ω_{6} + λ_{7} ω_{7}, \\ ω_{6} = \frac{N_{B \max} - N_{B}}{N_{B \max}}, \\ ω_{7} = \frac{N_{P \max} - N_{P}}{N_{P \max}}, \end{matrix}$

where λ₆is the sixth predefined indicator weight, λ₇is the seventh predefined indicator weight, ω₆is the relative failure frequency of the battery cluster in the energy storage station, N_Bmaxis the relative failure frequency of the process control system in the energy storage station, N_Bmaxis a battery-cluster failure frequency threshold of the energy storage station, N_Pmaxis a process-control-system failure frequency threshold of the energy storage station, N_Bis a battery-cluster stage-time failure frequency of the energy storage station, and N_Pis a process-control-system stage-time failure frequency of the energy storage station.

An indicator score of the power control is determined based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station.

Specifically, the power control indicator α₄is determined based on the following expression:

$α_{4} = λ_{8} ω_{8} + λ_{9} ω_{9} + λ_{1 0} ω_{1 0},$

where λ₈is the eighth predefined indicator weight, λ₉is the ninth predefined indicator weight, λ₁₀is the tenth predefined indicator weight, ω₈is the 1-minute active-power change rate of the energy storage station, ω₉is the 10-minute active-power change rate of the energy storage station, and ω₁₀is the up/down active-power adjustment speed of the energy storage station.

An indicator score of the peak-shaving and valley-filling capability of the system is determined based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station.

Specifically, the indicator α₅of peak-shaving and valley-filling capability is determined based on the following expression:

$α_{5} = λ_{1 1} ω_{1 1} + λ_{1 2} ω_{1 2} + λ_{1 3} ω_{1 3} + λ_{1 4} ω_{1 4},$

where λ₁₁is the eleventh predefined indicator weight, λ₁₂is the twelfth predefined indicator weight, λ₁₃is the thirteenth predefined indicator weight, λ₁₄is the fourteenth predefined indicator weight, ω₁₁is a maximum available charging power of the energy storage station, ω₁₂is a maximum available discharging power of the energy storage station, ω₁₃is a response lag time of the energy storage station, and ω₁₄is a steady-state control deviation of the energy storage station.

An indicator score of the system frequency regulation is determined based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station.

Specifically, the system frequency regulation indicator α₆is determined based on the following expression:

$α_{6} = λ_{1 5} ω_{1 5} + λ_{1 6} ω_{1 6} + λ_{1 7} ω_{1 7} + λ_{1 8} ω_{1 8},$

where, λ₁₅is the fifteenth predefined indicator weight, λ₁₆is the sixteenth predefined indicator weight, λ₁₇is the seventeenth predefined indicator weight, λ₁₈is the eighteenth predefined indicator weight, ω₁₅is a process-control-system protection-action time of frequency adaptability tests of the energy storage station, ω₁₆is a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, ω₁₇is an automatic-power-generation-control adjustment speed of the energy storage station, and ω₁₈is an automatic-power-generation-control adjustment precision of the energy storage station.

An indicator score of the reactive power support is determined based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station.

Specifically, the reactive power support indicator α₇is determined based on the following expression:

$α_{7} = λ_{1 9} ω_{1 9} + λ_{2 0} ω_{2 0} + λ_{2 1} ω_{2 1},$

where λ₁₉is the nineteenth predefined indicator weight, λ₂₀is the twentieth predefined indicator weight, λ₂₁is the twenty-first predefined indicator weight, ω₁₉is an automatic-voltage-control adjustment speed of the energy storage station, ω₂₀is an automatic-voltage-control adjustment precision of the energy storage station, and ω₂₁is an automatic-voltage-control response time of the energy storage station.

An indicator score of the response success rate is determined based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station.

Specifically, the response success rate indicator α₈is determined based on the following expression:

$α_{8} = \frac{N_{SUC}}{N_{T}} \times 1 0 0 %,$

where N_SUCis actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and N_Tis a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station.

An indicator score of the equivalent utilization coefficient is determined based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station.

Specifically, the equivalent utilization coefficient indicator α₉is determined based on the following expression:

$α_{9} = \frac{U T H}{P H} \times 1 0 0 %,$

where UTH is the number of the operating hours of the energy storage station, and PH is the number of the statistical hours within an evaluation period of the energy storage station.

An indicator score of the outage coefficient is determined based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and a number of statistical hours within the evaluation period of the energy storage station.

Specifically, the outage coefficient indicator α₁₀is determined based on the following expression:

$α_{1 0} = λ_{2 2} ω_{2 2} + λ_{2 3} ω_{2 3},$

$ω_{2 2} = \frac{U O H}{P H} \times 1 0 0 %,$

$ω_{2 3} = \frac{P O H}{P H} \times 1 0 0 %,$

where λ₂₂is the twenty-second predefined indicator weight, λ₂₃is the twenty-third predefined indicator weight, ω₂₂is an unplanned outage coefficient of the energy storage station, ω₂₃is a planned outage coefficient of the energy storage station, UOH is a number of unplanned outage hours of the energy storage station, POH is a number of planned outage hours of the energy storage station, and PH is a number of statistical hours within the evaluation period.

An indicator score of the availability coefficient is determined based on an available time of the energy storage station within the evaluation period and a number of statistical hours within the evaluation period of the energy storage station.

Specifically, the availability coefficient indicator α₁₁is determined based on the following expression:

$α_{1 1} = \frac{A H}{P H} \times 1 0 0 %,$

where AH is the available time of the energy storage station within the evaluation period and PH is the number of statistical hours within the evaluation period.

An indicator score of the frequency proactive support capability is determined based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of the system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located.

Specifically, the frequency proactive support capability indicator ω₁₂is determined based on the following expression:

$α_{12} = λ_{24} ω_{24} + λ_{25} ω_{25} + λ_{26} ω_{26},$

$ω_{24} = \frac{Δ P}{\overline{d} + α_{g}},$

$ω_{25} = \frac{Δ P}{\overline{M}},$

$ω_{26} = \frac{❘ Δ P ❘}{\overline{d} + α_{g}} (1 + \sqrt{\frac{{τα}_{g}}{\overline{M}}} e^{- \frac{η}{ω_{d}} (ϕ + \frac{π}{2})}),$

$ω_{d} \overset{Δ}{=} \sqrt{(d + α_{g}) τ^{- 1} {\overline{M}}^{- 1} - \frac{1}{4} {(τ^{- 1} + \overline{d} {\overline{M}}^{- 1})}^{2}},$

$η \overset{Δ}{=} \frac{1}{2} (τ^{- 1} + \overline{d} {\overline{M}}^{- 1}),$

where λ₂₄is the twenty-fourth predefined indicator weight, λ₂₅is the twenty-fifth predefined indicator weight, λ₂₆is the twenty-sixth predefined indicator weight, ω₂₄is a steady-state frequency deviation of the energy storage station, ω₂₅is a maximum frequency change rate of the energy storage station, ω₂₆is a maximum frequency deviation of the energy storage station, ΔP is an unbalanced power of the energy storage station, d is an equivalent damping of the energy storage system where the energy storage station is located, α_gis a primary frequency control intensity of the system where the energy storage station is located, M is an equivalent inertia of the system where the energy storage station is located, τ is the time constant, e is the natural constant, ϕ is the phase angle of the system where the energy storage station is located, and η±jω_dis the second-order pole of the system where the energy storage station is located, wherein j is the imaginary unit and has a different meaning from other instances of j herein.

An indicator score of the voltage proactive support capability is determined based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at regional power grid boundary nodes for which the energy storage station participates in regulation.

Specifically, the voltage proactive support capability indicator α₁₃is determined based on the following expression:

$α_{1 3} = ({\tilde{Q}}_{B} - {\tilde{Q}}_{B, r e f}) - K_{Q S} (U_{B} - U_{B, ref}),$

where {tilde over (Q)}_Bis a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, U_Bis a matrix of voltage at regional power grid boundary nodes of the energy storage station, K_QSis a matrix of parameters at regional power grid boundary nodes for which the energy storage station participates in regulation, {tilde over (Q)}_B,refis the reference value of the reactive power matrix, and U_B,refis the reference value of the voltage matrix at the grid boundary nodes.

An indicator score of the transient stability support capability is determined based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during transient processes, a frequency deviation at the grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station.

Specifically, the transient stability support capability indicator α₁₄is determined based on the following expression:

$α_{1 4} = \int [(Δ P_{i} \cdot 2 πΔ f_{i}) d t + Δ Q_{i} d (Δ \ln U_{i})],$

where ΔP_tis an additional active output of the energy storage station to the system during transient processes, ΔQ_iis an additional reactive output of the energy storage station to the system during transient processes, Δf_iis a frequency deviation at the grid connection point of the energy storage station, and Δln U_iis a natural logarithm voltage deviation at the grid connection point of the energy storage station.

An indicator score of the cost per unit of electricity is determined based on a total cost of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period.

Specifically, the indicator of cost per unit of electricity α₁₅is determined based on the following expression:

$α_{1 5} = \frac{C}{E_{D}},$

where C is a total cost of the energy storage station within the evaluation period and E_Dis a total discharging amount of the energy storage station within the evaluation period.

An indicator score of the net present value is determined based on the revenue of the energy storage station within the evaluation period, a cost, and a discount rate of the energy storage station within the evaluation period.

Specifically, the net present value indicator α₁₆is determined based on the following expression:

$α_{1 6} = \sum_{t = 1}^{n} (S_{t} - C_{t}) {(1 + γ)}^{- t},$

where S_tis the revenue of the energy storage station within the evaluation period, C_tis a cost within the evaluation period, γ is a discount rate, and t is the evaluation period of the energy storage station.

An indicator score of the return on investment is determined based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station.

Specifically, the indicator of return on investment α₁₇is determined based on the following expression:

$α_{1 7} = \frac{P_{r}}{TI} \times 1 0 0 %,$

where P_ris the annual-interest pre-tax profit in a normal year for the energy storage station, and TI is the total investment for the energy storage station.

An indicator score of the carbon emission reduction is determined based on a carbon emission coefficient and a released renewable energy amount of the energy storage station.

Specifically, the carbon emission reduction indicator α₁₈is determined based on the following expression:

$α_{1 8} = \sum_{t = 1}^{n} e_{CO 2} E_{Dt},$

where e_CO2is a carbon emission coefficient and E_Dtis a released renewable energy amount of the energy storage station, and n is the number of energy storage stations.

An indicator score of the effective emission reduction rate is determined based on a clean energy generation amount of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period.

Specifically, the indicator α₁₉of effective emission reduction rate is determined based on the following expression:

$α_{1 9} = \frac{\sum E_{C D}}{\sum E_{D}} \times 1 0 0 %,$

where E_CDis a clean energy generation amount of the energy storage station within the evaluation period and E_Dis a total discharging amount of the energy storage station within the evaluation period.

An indicator score of the clean energy absorption rate is determined based on a clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.

Specifically, the indicator α₂₀of clean energy absorption rate is determined based on the following expression:

$α_{2 0} = \frac{E_{C D}}{E_{CD \max}},$

where E_CDis a clean energy generation amount of the energy storage station within the evaluation period and E_CDmaxis a maximum clean energy generation amount of the energy storage station.

In one feasible embodiment, the objective weighting method is the CRITIC weighting method.

Specifically, the CRITIC weighting method is an objective weighting method based on the volatility of data.

In one feasible embodiment as shown in FIG. 2, FIG. 2 illustrates a flowchart of the method for determining a comprehensive weight provided in one embodiment of the present disclosure. The step of determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station includes the following steps S201 to S202.

S201: establishing an objective function based on the minimum discrimination information principle for determining the comprehensive weight.

Specifically, when the quantity of at least one energy storage station is n, and each energy storage station includes m evaluation indicators, for the j-th evaluation indicator of the i-th energy storage station, where n, m, i, and j are all non-zero natural numbers, with 1≤i≤n and 1≤j≤m, the objective function is:

${\begin{matrix} \min F (w) = \sum_{j = 1}^{m} (w_{i} \ln \frac{w_{i}}{w_{j}^{A}} + w_{i} \ln \frac{w_{i}}{w_{j}^{S}}) \\ \begin{matrix} \sum_{j = 1}^{m} w_{j} = 1, w_{j} \geq 0 & j = 1, 2, \dots, m \end{matrix} \end{matrix},$

where min F (w) is the minimum discriminant information function between subjective and objective weights, w_iis the independent variable of the objective function, w_j^Ais the objective weight of the j-th evaluation indicator of the energy storage station, and w_j^Sis the subjective weight of the j-th evaluation indicator of the energy storage station.

S202: utilizing the objective function to determine a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

Specifically, for the j-th evaluation indicator of the energy storage station, the objective weight and subjective weight of the j-th evaluation indicator of the energy storage station are input into the objective function. The objective function is solved to obtain the comprehensive weight w_jof the j-th evaluation indicator of the energy storage station.

$w_{j} = \frac{\sqrt{w_{j}^{A} w_{j}^{S}}}{Σ_{j = 1}^{m} \sqrt{w_{j}^{A} w_{j}^{S}}};$

where w_jis the comprehensive weight of the j-th evaluation indicator of the energy storage station, w_j^Ais the objective weight of the j-th evaluation indicator of the energy storage station, w_j^Sis the subjective weight of the j-th evaluation indicator of the energy storage station, and m is the number of evaluation indicators of the energy storage station.

Embodiment 2

As shown in FIG. 3, FIG. 3 illustrates a schematic structural diagram of a device for determining the grade of an energy storage station based on an index evaluation system based on another embodiment of the present disclosure, wherein the device includes

- an indicator score acquisition module 301, configured for obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station;
- an objective weight determination module 302, configured for utilizing an objective weighting method based on the indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station;
- a subjective weight determination module 303, configured for utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station;
- a comprehensive weight determination module 304, configured for determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station; and
- an evaluation grade determination module 305, configured for utilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, the TOPSIS method to determine an evaluation grade of each energy storage station.

In one feasible embodiment, the at least one evaluation indicator includes

- a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.

In one feasible embodiment, the indicator score acquisition module is configured for obtaining an indicator score of at least one evaluation indicator of the energy storage station, which is specifically configured for

- determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station;
- determining an indicator score of the energy efficiency level based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station;
- determining an indicator score of the failure frequency based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station;
- determining an indicator score of the power control based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station;
- determining an indicator score of the peak-shaving and valley-filling capability of a system based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station;
- determining an indicator score of the system frequency regulation based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station;
- determining an indicator score of the reactive power support based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station;
- determining an indicator score of the response success rate based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station;
- determining an indicator score of the equivalent utilization coefficient based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station;
- determining an indicator score of the outage coefficient based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the availability coefficient based on an available time of the energy storage station within the evaluation period and a number of statistical hours within the evaluation period of the energy storage station;
- determining an indicator score of the frequency proactive support capability based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of the system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located;
- determining an indicator score of the voltage proactive support capability based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at regional power grid boundary nodes for which the energy storage station participates in regulation;
- determining an indicator score of the transient stability support capability based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during transient processes, a frequency deviation at the grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station;
- determining an indicator score of the cost per unit of electricity based on a total cost of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period;
- determining an indicator score of the net present value based on the revenue of the energy storage station within the evaluation period, a cost and a discount rate of the energy storage station within the evaluation period;
- determining an indicator score of the return on investment based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station;
- determining an indicator score of the carbon emission reduction based on a carbon emission coefficient and a released renewable energy amount of the energy storage station;
- determining an indicator score of the effective emission reduction rate based on a clean energy generation amount of the energy storage station within the evaluation period and a total discharging amount of the energy storage station within the evaluation period; and
- An indicator score of the clean energy absorption rate is determined based on a clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.

In one feasible embodiment, the objective weighting method is the CRITIC weighting method.

In one feasible embodiment, the comprehensive weight determination module is configured for determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station, which is specifically configured for

- establishing an objective function based on the minimum discrimination information principle for determining the comprehensive weight; and
- utilizing the objective function to determine a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

The device for determining the grade of an energy storage station based on an index evaluation system, as provided in the embodiment of the present disclosure, can be implemented as specific hardware on the device or as software or firmware installed on the device. The device provided by the embodiment of the present disclosure is implemented with the same principles and produces the same technical effects as the aforementioned method embodiment. For a brief description, where the embodiment part of the device is not mentioned, the corresponding contents of the aforementioned embodiment method can be referred to. It will be clear to those skilled in the field that, for the convenience and brevity of the description, the specific working processes of the systems, devices, and units described above can be referred to as the corresponding processes in the preceding method embodiments and will not be repeated here.

In the embodiments provided in the present disclosure, it should be understood that the systems, devices, and methods disclosed, can be implemented in other ways. The above-described embodiments of the device are merely schematic, for example, the division of the units described, which is only a logical functional division, can be divided in another way when actually implemented; also, for example, multiple units or components can be combined or can be integrated into another system, or some features can be ignored, or not implemented. On another point, the mutual coupling, direct coupling, or communication connection discussed herein can be an indirect coupling or communication connection through communication interfaces, devices, or units, which can be electrical, mechanical, or other forms.

The units illustrated as separate components may/may not be physically separated, and the components displayed as units may/may not be physical units, i.e., they can be located in one place or distributed to a plurality of network units. Some or all of these units can be selected according to actual needs to achieve the objective of the embodiment solution.

Further, each functional unit in the embodiments of the present disclosure can be integrated into a single processing unit, each unit can be physically present separately, or two or more units can be integrated into a single unit.

The functionality, when implemented as a software functional unit and sold or used as a stand-alone product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure can essentially be embodied in the form of a software product, which contributes to or includes parts of the existing technology. The software product is stored in a storage medium and includes multiple instructions for causing a computer device (which can be a personal computer, server, network device, etc.) to execute all or some of the steps of the methods described in various embodiments of the present disclosure. The aforementioned storage media comprises various media that can store program code, such as various media that can store program code, such as USB flash drives, mobile hard drives, Read-Only Memory (ROM), Random Access Memory (RAM), disks, or CD-ROMs.

It should be noted that similar numerals and letters denote similar terms in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings. In addition, the terms “first”, “second”, and “third” are only used to distinguish the descriptive and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that the embodiments described above are specific implementations of the present disclosure used to illustrate the technical solutions of the present disclosure and are not intended to limit its scope. The scope of protection of the present disclosure is not limited to these embodiments, despite the detailed description provided in reference to the aforementioned embodiments. It should be understood by those of ordinary skill in the art that any person skilled in the art can still make modifications or easily envisage variations to the technical solutions described in the aforementioned embodiments within the technical scope disclosed by the present disclosure. Alternatively, some technical features can be equivalently substituted. These modifications, changes, or replacements do not take the essence of the corresponding technical solutions out of the essence and scope of the technical solutions of the embodiments of the present disclosure. All should be covered within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be determined by the scope of protection of the claims.

Claims

1. A method for determining a grade of an energy storage station based on an index evaluation system, wherein the method comprises obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station;utilizing an objective weighting method based on an indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station;utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station;determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station; andutilizing, based on the comprehensive weight of each evaluation indicator of each energy storage station, a TOPSIS method to determine an evaluation grade of each energy storage station.
2. The method according to claim 1, wherein the at least one evaluation indicator comprises a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.
3. The method according to claim 2, wherein the step of obtaining an indicator score of at least one evaluation indicator of the energy storage station comprises determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station;determining an indicator score of the energy efficiency level based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station;determining an indicator score of the failure frequency based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station;determining an indicator score of the power control based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station;determining an indicator score of the peak-shaving and valley-filling capability of the system based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station;determining an indicator score of the system frequency regulation based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station;determining an indicator score of the reactive power support based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station;determining an indicator score of the response success rate based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within a preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station;determining an indicator score of the equivalent utilization coefficient based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station;determining an indicator score of the outage coefficient based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and the number of the statistical hours within the evaluation period of the energy storage station;determining an indicator score of the availability coefficient based on an available time of the energy storage station within the evaluation period and the number of the statistical hours within the evaluation period of the determining an indicator score of the frequency proactive support capability based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of a system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located;determining an indicator score of the voltage proactive support capability based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at the regional power grid boundary nodes for which the energy storage station participates in regulation;determining an indicator score of the transient stability support capability based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during the transient processes, a frequency deviation at a grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station;determining an indicator score of the cost per unit of electricity based on a total cost of the energy storage station within the evaluation period and the total discharging amount of the energy storage station within the evaluation period;determining an indicator score of the net present value based on a revenue of the energy storage station within the evaluation period, a cost and a discount rate of the energy storage station within the evaluation period;determining an indicator score of the return on investment based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station;determining an indicator score of the carbon emission reduction based on a carbon emission coefficient and a released renewable energy amount of the energy storage station;determining an indicator score of the effective emission reduction rate based on a clean energy generation amount of the energy storage station within the evaluation period and the total discharging amount of the energy storage station within the evaluation period; anddetermining an indicator score of the clean energy absorption rate based on the clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.
4. The method according to claim 1, wherein the objective weighting method is a CRITIC weighting method.
5. The method according to claim 1, wherein the step of determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station comprises establishing an objective function based on a minimum discrimination information principle for determining the comprehensive weight; andutilizing the objective function to determine the comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.
6. A device for determining a grade of an energy storage station based on an index evaluation system, wherein the device comprises an indicator score acquisition module, configured for obtaining, for at least one energy storage station, an indicator score of at least one evaluation indicator of the energy storage station;an objective weight determination module, configured for utilizing an objective weighting method based on an indicator score of each evaluation indicator of the energy storage station to determine an objective weight of each evaluation indicator of the energy storage station;a subjective weight determination module, configured for utilizing a DEMATEL-ANP mixed decision-making model based on the indicator score of each evaluation indicator of the energy storage station to determine a subjective weight of each evaluation indicator of the energy storage station;a comprehensive weight determination module, configured for determining a comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station; andan evaluation grade determination module, configured for utilizing, based on a comprehensive weight of each evaluation indicator of each energy storage station, a TOPSIS method to determine an evaluation grade of each energy storage station.
7. The device according to claim 6, wherein the at least one evaluation indicator comprises a charge and discharge capacity, an energy efficiency level, a failure frequency, a power control, a peak-shaving and valley-filling capability of a system, a system frequency regulation, a reactive power support, a response success rate, an equivalent utilization coefficient, an outage coefficient, an availability coefficient, a frequency proactive support capability, a voltage proactive support capability, a transient stability support capability, a cost per unit of electricity, a net present value, a return on investment, a carbon emission reduction, an effective emission reduction rate, and a clean energy absorption rate.
8. The device according to claim 7, wherein the indicator score acquisition module is configured for obtaining the indicator score of at least one evaluation indicator of the energy storage station, comprising determining an indicator score of the charge and discharge capacity based on an actual dischargeable power of the energy storage station, a rated power of the energy storage station, an actual dischargeable volume of the energy storage station, and a rated energy of the energy storage station; determining an indicator score of the energy efficiency level based on an on-grid electricity of the energy storage station, an off-grid electricity of the energy storage station, a total charging amount of the energy storage station, a total discharging amount of the energy storage station, and a self-consumption electricity of the energy storage station;determining an indicator score of the failure frequency based on a battery-cluster failure frequency threshold of the energy storage station, a process-control-system failure frequency threshold of the energy storage station, a battery-cluster stage-time failure frequency of the energy storage station, and a process-control-system stage-time failure frequency of the energy storage station;determining an indicator score of the power control based on an active-power change rate of the energy storage station and an up/down active-power adjustment speed of the energy storage station;determining an indicator score of the peak-shaving and valley-filling capability of the system based on a maximum available charging power of the energy storage station, a maximum available discharging power of the energy storage station, a response lag time of the energy storage station, and a steady-state control deviation of the energy storage station;determining an indicator score of the system frequency regulation based on a process-control-system protection-action time of frequency adaptability tests of the energy storage station, a process-control-system protection-action frequency of the frequency adaptability tests of the energy storage station, an automatic-power-generation-control adjustment speed of the energy storage station, an automatic-power-generation-control adjustment precision of the energy storage station, and an automatic-power-generation-control response time of the energy storage station;determining an indicator score of the reactive power support based on an automatic-voltage-control adjustment speed of the energy storage station, an automatic-voltage-control adjustment precision of the energy storage station, and an automatic-voltage-control response time of the energy storage station;determining an indicator score of the response success rate based on actual execution success times of an automatic-voltage-control and automatic-power-generation-control instructions from a grid within the preset operation scheduling cycle of the energy storage station, and a total number of the automatic-voltage-control and automatic-power-generation-control instructions issued by the grid to the energy storage station;determining an indicator score of the equivalent utilization coefficient based on a number of operating hours of the energy storage station and a number of statistical hours within an evaluation period of the energy storage station;determining an indicator score of the outage coefficient based on an unplanned outage coefficient of the energy storage station, a planned outage coefficient of the energy storage station, a number of unplanned outage hours of the energy storage station, a number of planned outage hours of the energy storage station, and the number of the statistical hours within the evaluation period of the energy storage station;determining an indicator score of the availability coefficient based on an available time of the energy storage station within the evaluation period and the number of the statistical hours within the evaluation period of the determining an indicator score of the frequency proactive support capability based on a steady-state frequency deviation of the energy storage station, a maximum frequency change rate of the energy storage station, a maximum frequency deviation of the energy storage station, an unbalanced power of the energy storage station, an equivalent damping of a system where the energy storage station is located, a primary frequency control intensity of the system where the energy storage station is located, and an equivalent inertia of the system where the energy storage station is located;determining an indicator score of the voltage proactive support capability based on a matrix of reactive power flowing from regional power grid boundary to internal regions for which the energy storage station participates in regulation, a matrix of voltage at regional power grid boundary nodes for which the energy storage station participates in regulation, and a matrix of parameters at the regional power grid boundary nodes for which the energy storage station participates in regulation;determining an indicator score of the transient stability support capability based on an additional active output of the energy storage station to the system during transient processes, an additional reactive output of the energy storage station to the system during the transient processes, a frequency deviation at a grid connection point of the energy storage station, and a natural logarithm voltage deviation at the grid connection point of the energy storage station;determining an indicator score of the cost per unit of electricity based on a total cost of the energy storage station within the evaluation period and the total discharging amount of the energy storage station within the evaluation period;determining an indicator score of the net present value based on a revenue of the energy storage station within the evaluation period, a cost and a discount rate of the energy storage station within the evaluation period;determining an indicator score of the return on investment based on an annual-interest pre-tax profit of the energy storage station in a normal year and a total investment of the energy storage station;determining an indicator score of the carbon emission reduction based on a carbon emission coefficient and a released renewable energy amount of the energy storage station;determining an indicator score of the effective emission reduction rate based on a clean energy generation amount of the energy storage station within the evaluation period and the total discharging amount of the energy storage station within the evaluation period; anddetermining an indicator score of the clean energy absorption rate based on the clean energy generation amount of the energy storage station within the evaluation period and a maximum clean energy generation amount of the energy storage station.
9. The device according to claim 6, wherein the objective weighting method is a CRITIC weighting method.
10. The device according to claim 6, wherein the comprehensive weight determination module is configured for determining the comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station, comprising establishing an objective function based on a minimum discrimination information principle for determining the comprehensive weight; andutilizing the objective function to determine the comprehensive weight of each evaluation indicator of the energy storage station based on the objective weight and the subjective weight of each evaluation indicator of the energy storage station.

Priority Claims (1)

Number	Date	Country	Kind
202310527757.5	May 2023	CN	national

Method and Device for Determining Grade of Energy Storage Station Based on Index Evaluation System

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CPC

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Priority Claims (1)