Method for evaluating minimum inertia of power system by considering network construction type energy storage frequency response

Abstract

The invention discloses an electric power system minimum inertia evaluation method considering network construction type energy storage frequency response, and the method comprises the steps: constructing an active-frequency coupling model according to a network construction type energy storage principle, and further building a network construction type energy storage-containing electric power system frequency response model; and then analyzing the frequency characteristics containing the network construction type energy storage, calculating the inertia of the system by adopting a sliding window technology, and evaluating the minimum inertia demand of the system in combination with the frequency characteristic constraint. According to the method, a guidance basis is provided for reasonable configuration of the system frequency modulation resources under large-scale network construction type energy storage access, so that the system frequency modulation resources can be configured more reasonably.

Description

Technical Field

[0001] The present invention belongs to the field of minimum inertia evaluation of power systems, and in particular relates to a minimum inertia evaluation method for power systems taking into account the frequency response of grid-type energy storage. Background Art

[0002] In response to the call of the "dual carbon" goal, China is accelerating the construction of a new power system dominated by new energy and power electronic equipment, and grid-forming control technology has emerged. The grid-forming (GFM) control strategy has stronger frequency support capabilities in scenarios with high new energy penetration; in addition, as a means of smoothing out the fluctuations in new energy power generation, reducing the peak load pressure of large power grids, and improving the acceptance level of large power grids for new energy, energy storage is a must.

[0003] In the study of grid-type energy storage to improve grid frequency stability, the existing technology introduces the control method of grid-type energy storage, simulates and analyzes its effect on improving the transient frequency stability of the grid; studies the control advantages of grid-type energy storage compared to grid-type energy storage in low-inertia systems; the control strategy and modeling method of grid-type energy storage supporting new power system grids involve multi-variable influences, dynamics and nonlinearity, complex control strategies, uncertainty factors and coupling effects, which lead to complex models. In order to simplify the model, some studies have quickly analyzed the dynamic frequency characteristics of the system under multiple scenarios, established a linear model of active power-frequency changes to analyze the effectiveness of the control strategy, and established an extended system frequency response (ESFR) equivalent model of energy storage access to the grid. Under the background of combining renewable energy generation with electric energy storage systems (ESS), the use of grid-type control as a solution is undoubtedly the most suitable. Summary of the invention

[0004] The purpose of the present invention is to provide a method for evaluating the minimum inertia of a power system taking into account the frequency response of grid-connected energy storage, thereby providing guidance for the effective access of large-scale grid-connected energy storage and enabling a more reasonable allocation of system frequency regulation resources.

[0005] In order to achieve the above object, the solution of the present invention is:

[0006] A method for evaluating the minimum inertia of a power system considering the frequency response of grid-connected energy storage includes:

[0007] Construct active power-frequency coupling model of grid-connected energy storage;

[0008] Based on the active power-frequency coupling model of the grid-forming energy storage, a frequency response model of the power system including the grid-forming energy storage is constructed;

[0009] For the constructed power system frequency response model containing grid-connected energy storage, the sliding window technology is combined with frequency characteristic constraints to evaluate the system minimum inertia requirement taking into account the frequency characteristics.

[0010] Furthermore, a grid-connected energy storage active power-frequency coupling model is constructed, including: the dynamic equation of the control link of the model is:

[0011]

[0012] Among them, ω p is the frequency of the equivalent internal potential of the virtual synchronous machine; ω g is the actual power grid frequency; P pk is the actual value of active power; P pkr is the reference value of active power; D sg is the damping coefficient of the virtual synchronous machine; H sg is the inertia constant of the virtual synchronous machine; s is the Lagrangian operator.

[0013] Furthermore, a frequency response model of a power system including grid-connected energy storage is constructed, including: the transfer function of the model is:

[0014]

[0015] Among them, k E is the additional control proportional coefficient of energy storage frequency, T E is the inner loop control response time constant, s is the Laplace operator; ΔP E is the power change delivered by the energy storage system, and Δf is the AC bus frequency.

[0016] Furthermore, the minimum inertia requirement of the system taking into account the frequency characteristics is evaluated, including,

[0017] Select the time interval with the smallest fluctuation on the curve. The starting point of the time interval is the disturbance occurrence time point t1, and the end point is the sampling time point t2. Calculate the inertia evaluation result according to the following formula:

[0018]

[0019]

[0020]

[0021] in, is the average value of inertia in the sampling interval; υ is the number of data in the sampling interval; The sampling time t2 is equal to t n The calculated inertia value at t is t; τ is the initial sampling time of the current time interval; E Csys' is the equivalent inertia value of the system; υ' is the number of data in the effective sampling time interval.

[0022] Furthermore, the minimum inertia requirement of the system taking into account the frequency characteristics is evaluated, including,

[0023] The minimum inertia requirement evaluation value under the power system is calculated as follows:

[0024]

[0025] Among them, ΔP max is the maximum active power disturbance.

[0026] Furthermore, the minimum inertia requirement of the system taking into account the frequency characteristics is evaluated, including,

[0027] When multiple resources participate in frequency regulation, the maximum frequency deviation of the power system Δf max The absolute value does not exceed 1Hz, and the grid steady-state frequency deviation Δf ss The absolute value shall not exceed 0.2Hz, and the minimum inertia shall be the larger value of the minimum inertia that meets the above two conditions.

[0028] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the steps of the method for evaluating the minimum inertia of a power system taking into account the frequency response of a grid-connected energy storage as described above are implemented.

[0029] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the steps of the method for evaluating the minimum inertia of a power system taking into account the frequency response of a grid-connected energy storage as described above are implemented.

[0030] After adopting the above scheme, the beneficial effects of the present invention are as follows: according to the principle of grid-type energy storage, its active power-frequency coupling model is constructed, and further a frequency response model of the power system containing grid-type energy storage is established; then the frequency characteristics of the grid-type energy storage are analyzed, and the system inertia is calculated by using the sliding window technology, and the minimum inertia requirement of the system is evaluated in combination with the frequency characteristic constraint, so as to provide a guiding basis for the rational configuration of the system frequency regulation resources under the access of large-scale grid-type energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of the present invention;

[0032] Figure 2 It is a flow chart for the minimum inertia assessment of a power system containing grid-type energy storage;

[0033] Figure 3 It is a topological diagram of the grid-type energy storage structure;

[0034] Figure 4 It is the system frequency simulation diagram;

[0035] Figure 5 It is the frequency characteristic curve of the power system;

[0036] Among them, (a) is the RoCoF curve, and (b) is the system frequency deviation diagram. DETAILED DESCRIPTION

[0037] The present invention provides a method for evaluating the minimum inertia of a power system considering the frequency response of a grid-connected energy storage, comprising:

[0038] Analyze the principle of grid-type energy storage and construct an active-frequency coupling model of grid-type energy storage;

[0039] Based on the active power-frequency coupling model of the grid-type energy storage established above, a frequency response model of the power system containing the grid-type energy storage is constructed, and the frequency characteristics of the grid-type energy storage are analyzed;

[0040] For the above-mentioned power system frequency response model containing grid-connected energy storage, the sliding window technology is combined with frequency characteristic constraints to evaluate the system minimum inertia requirement taking into account the frequency characteristics.

[0041] The technical solutions and beneficial effects of the present invention will be described in detail below in conjunction with specific embodiments.

[0042] like Figure 1 As shown, the following steps are included:

[0043] S1 analyzes the principle of grid-type energy storage and constructs an active-frequency coupling model of grid-type energy storage, including:

[0044] S11. Grid-type control no longer relies on a phase-locked loop to track the grid phase, but autonomously builds frequency and voltage like a virtual synchronous generator (VSG), and uses the total active and reactive power at the grid-connected outlet as feedback for VSG control. It can be concluded that the grid-type converter adjusts power by directly controlling the voltage at the output end.

[0045] A major feature of VSG control is the power control command. Before introducing the power command, the essence of inverter power control can be summarized from a macro perspective. First, the power command is compared with the output power fed back, and then the PWM wave is adjusted. The essence of the PWM wave is to manipulate the on and off of the inverter semiconductor devices to obtain the target voltage or target current. Adjusting the PWM wave will change the output voltage of the inverter accordingly. This cycle will continue until the inverter output power meets the requirements. In the voltage-type VSG control link, the frequency and initial phase are derived from the rotor mechanical equation, and the amplitude is obtained from the virtual excitation link.

[0046] S12. Active-frequency coupling model is a mathematical model that describes the energy storage system's response to grid frequency changes. It is usually established based on the control strategy and the physical characteristics of the energy storage system. The dynamic equation of the control link is:

[0047]

[0048] Where: p is the frequency of the VSG equivalent internal potential; ω g is the actual power grid frequency; P pk is the actual value of active power; P pkr is the reference value of active power; D sg is the damping coefficient of VSG; H sg is the inertia constant of VSG; s is the Lagrangian operator.

[0049] S2, based on the above-established grid-type energy storage active power-frequency coupling model, construct a power system frequency response model containing grid-type energy storage, and analyze the frequency characteristics of the grid-type energy storage, including:

[0050] The traditional frequency model analysis method adopts the Center of Inertia (COI) assumption, that is, the system inertia is concentrated on an equivalent center of inertia, simplifying the system into a single-node system:

[0051]

[0052] Where H is the equivalent inertia time constant of the system; D is the damping constant, ΔP L is the load active disturbance, R is the adjustment coefficient, F H is the work coefficient of the prime mover high pressure cylinder, T R is the reheat time constant, k m is the mechanical power factor, Δf COI This is the change in the center frequency of inertia.

[0053] In order to alleviate the frequency regulation pressure of the new energy system, the power system is connected to a grid-type energy storage device to participate in auxiliary frequency regulation. According to the energy storage method, energy storage can be divided into physical energy storage, electromagnetic field energy storage and electrochemical energy storage. This embodiment takes electrochemical energy storage as an example, adds a frequency additional controller to the outer loop control side of the DC / DC converter to integrate energy storage into the new energy side, and establishes a grid-type energy storage frequency response model, and its frequency additional control proportional coefficient is determined by the AC bus frequency Δf.

[0054] The transfer function of the frequency response model of the energy storage system with additional frequency control is:

[0055]

[0056] Where: kE is the additional control proportional coefficient of energy storage frequency, T E is the inner loop control response time constant, ΔP E Send power changes to the energy storage system.

[0057] S3 uses the sliding window technology combined with frequency characteristic constraints to evaluate the minimum inertia requirement of the system taking into account the frequency characteristics for the power system frequency response model with grid-connected energy storage constructed above. Figure 2 As shown, specifically including:

[0058] Step 31: The real-time inertia values ​​calculated by the sliding window are the basic data for evaluating RoCoF and frequency deviation. These inertia values ​​reflect the current dynamic state of the system.

[0059] Step 32: The evaluation of RoCoF constraints is to ensure that the system does not experience excessive frequency changes at the moment of frequency disturbance. It is the first line of defense to ensure system stability.

[0060] Step 33, the evaluation of the frequency deviation constraint is to further ensure the frequency stability of the system after the initial disturbance. On the basis of satisfying the RoCoF constraint, it is also necessary to ensure that the frequency deviation is within the allowable range to avoid long-term frequency deviation.

[0061] S31. Inertia calculation based on sliding window: In order to reduce the calculation error of inertia evaluation, a data processing technology based on sliding window is used to calculate the inertia of the power system. This embodiment replaces the traditional evaluation method of collecting RoCoF of a single node by sampling data parameters at two different times t1 and t2, where t1 is the time point when the disturbance occurs, t2 is the sampling time point, and the time interval is defined as the time period from t1 to the end of sampling, and the sampling interval is defined as the time period from t2 to the end of sampling. Based on the sliding window technology, the time interval with the smallest fluctuation on the system frequency curve is selected, and the sampling values ​​therein are calculated to obtain the average value of the time interval. The inertia evaluation results are as follows:

[0062]

[0063]

[0064]

[0065] In the formula, is the average value of inertia in the sampling interval; υ is the number of data in the sampling interval; The sampling time t2 is equal to t n The calculated inertia value at t is t; τ is the initial sampling time of the current time interval; E Csys ' is the equivalent inertia value of the system; υ' is the number of data in the effective sampling time interval.

[0066] S32. Minimum inertia requirement assessment considering RoCoF constraints: If the RoCoF of the power system after a disturbance does not exceed a certain critical value is constrained, the maximum RoCoF should be used as the parameter benchmark.

[0067] When power imbalance occurs, the power system has no frequency deviation at the moment of disturbance, and the frequency change of the power system depends on the system equivalent inertia time constant and the size of the active power disturbance.

[0068] The minimum inertia of the power system based on RoCoF constraints is

[0069]

[0070] It indicates that the system is subjected to the maximum active power disturbance ΔP max In order to make the center RoCoF not exceed the critical value RocoF max , the system inertia after disturbance shall not be less than H min .

[0071] Since the maximum RoCoF is the initial RoCoF, the formula can be expressed as

[0072]

[0073] Where: S 0_sys is the initial RoCoF value (system frequency change value).

[0074] The minimum inertia requirement evaluation value under the actual power system is

[0075]

[0076] According to the formula, the greater the source-load active power imbalance, or the RocoF max The smaller it is, the greater the minimum inertia constraint of the power system is, and vice versa. The minimum inertia requirement of the power system is related to the size of the active disturbance and the initial RoCoF.

[0077] S33. Evaluation of minimum inertia requirement considering frequency deviation constraint: The frequency characteristics of power systems under different grid architectures are different. Therefore, in order to prevent the grid from suffering a major blackout due to low-frequency load reduction when the grid is subjected to a large disturbance, the system inertia support capability needs to consider the grid frequency characteristics under the frequency regulation of multiple resources.

[0078] When traditional thermal power, wind power, and HVDC jointly participate in frequency regulation, the lowest point of the grid frequency shall not be lower than the third line of defense low-frequency load reduction action value, that is, the maximum frequency deviation Δf of the new power system under multi-resource frequency regulation maxThe absolute value does not exceed 1Hz (abnormal operation state). When the frequency curve tends to be stable, the frequency steady-state characteristics reflect the system inertia characteristics during normal operation in the later stage of frequency regulation, and the grid steady-state frequency deviation size Δf ss The absolute value shall not exceed 0.2Hz. Therefore, the minimum inertia of the power system considering the frequency deviation constraint can be taken as the larger value of the minimum inertia that satisfies the above two conditions, that is,

[0079]

[0080] in, To meet the minimum inertia value under the maximum frequency deviation of the power system; To meet the minimum inertia value under steady-state frequency deviation of the power grid.

[0081] In the later stage of the disturbance of the power grid under safe and stable operation, the influence of the spatial distribution characteristics of the power grid is weakened. Therefore, based on the classic SFR model, a power grid frequency response model with multiple resources participating in frequency regulation is established, and the equivalent inertia of the power system under the constraint of maximum frequency deviation is quantitatively studied.

[0082] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

[0083] Example

[0084] In order to verify the feasibility of the power system minimum inertia evaluation method considering the frequency response of grid-type energy storage proposed in this invention, the transient frequency stability analysis of the improved IEEE 10-machine 39-node system was carried out using the PSD-BPA simulation platform. Four grid-type energy storage units were connected to nodes 31, 33, 38, and 39, respectively. Figure 3 shown.

[0085] The effectiveness of the proposed virtual method can be verified by observing the changes in the inertia and damping characteristics of the system after the fault. The fault is set as a sudden load increase fault, that is, at t = 1s, 1pu of active load is connected to nodes 5, 33, 34, and 37. First, in order to verify the frequency regulation capability of this grid-type coordinated energy storage control. The total simulation time is 5s. The system frequency of this simulation at 1.0~5.0s is as follows Figure 4 shown.

[0086] like Figure 4It can be seen that without the coordinated control of grid-type energy storage, the system frequency dropped by 0.3Hz, and the system frequency did not reach stability after the subsequent 4s; with the coordinated control of grid-type energy storage, the system frequency dropped by 0.2Hz, and the system frequency did not reach stability after the subsequent 4s; the frequency of this grid-type coordinated energy storage control dropped by 0.5Hz at 1.0-2.0s, and its frequency can be restored to the rated value of about 50Hz in about 0.8-3.2s. Therefore, it can be proved that this grid-type coordinated energy storage control has good dynamic response performance, and the active-frequency modulation link plays a role.

[0087] In order to further illustrate the effectiveness of the method of the present invention, the inertia evaluation under the RoCoF constraint proposed in this embodiment is verified.

[0088] The inertia assessment method based on the grid-type energy storage frequency response model can reflect the changes in the equivalent inertia and frequency response of the power system under the frequency regulation of multiple resources. The traditional frequency regulation method only considers the inertia support capacity of the traditional synchronous generator set, so the frequency response model only includes the traditional synchronous generator with the grid-type energy storage frequency control structure. Observe the frequency characteristics of the power system under different frequency regulation methods. When the system is subjected to an active disturbance of 1p.u., the RoCoF curve and frequency characteristic curve are as follows: Figure 5 shown.

[0089] Depend on Figure 5 (a) It can be seen that the initial frequency change rate under the frequency modulation method proposed in this embodiment is -1.01 Hz·s -1 , the system initial frequency change rate under the traditional frequency modulation method -1.20Hz·s -1 Because the sliding window is used to process the data, it can effectively deal with the sharp drop in frequency. Figure 5 (b) It can be seen that the method proposed in this embodiment can quickly and accurately deal with frequency faults. The specific system simulation results are shown in Table 1.

[0090] Table 1 System simulation results

[0091]

[0092] The method of this embodiment optimizes the recovery of the system frequency after the frequency disturbance, successfully increases the steady-state frequency by 0.02%, and effectively prevents the frequency from continuously decreasing, thereby achieving a rapid frequency modulation effect.

[0093] An embodiment of the present invention further provides another computer device, including a processor and a memory configured to store a computer program that can be run on the processor; wherein, when the processor is configured to run the computer program, the method steps in the aforementioned embodiment are executed.

[0094] In practical applications, the processor includes a field programmable gate array (FPGA), and the processor may be a central processing unit (CPU) or a digital signal processor (DSP). It is understandable that for different devices, the electronic device used to implement the function of the processor may be other, and the embodiment of the present invention does not specifically limit it.

[0095] The above-mentioned memory can be a volatile memory (volatile memory), such as a random access memory (RAM); or a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory, a hard disk (HDD) or a solid-state drive (SSD); or a combination of the above-mentioned types of memory, and provide instructions and data to the processor.

[0096] In an exemplary embodiment, an embodiment of the present invention further provides a computer-readable storage medium for storing a computer program.

[0097] Optionally, the computer-readable storage medium can be applied to any one of the methods in the embodiments of the present invention, and the computer program enables the computer to execute the corresponding processes implemented by the processor in each method in the embodiments of the present invention. For the sake of brevity, they are not described here.

[0098] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0099] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0100] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0101] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0103] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0104] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for evaluating the minimum inertia of a power system considering the frequency response of grid-connected energy storage, characterized in that: include, Construct active power-frequency coupling model of grid-connected energy storage; Based on the active power-frequency coupling model of the grid-forming energy storage, a frequency response model of the power system including the grid-forming energy storage is constructed; For the constructed power system frequency response model containing grid-connected energy storage, the sliding window technology is combined with frequency characteristic constraints to evaluate the system minimum inertia requirement taking into account the frequency characteristics.

2. The method according to claim 1, characterized in that: A grid-type energy storage active-frequency coupling model is constructed, including: the dynamic equation of the control link of the model is: Among them, ω p is the frequency of the equivalent internal potential of the virtual synchronous machine; ω g is the actual power grid frequency; P pk is the actual value of active power; P pkr is the reference value of active power; D sg is the damping coefficient of the virtual synchronous machine; H sg is the inertia constant of the virtual synchronous machine; s is the Lagrangian operator.

3. The method according to claim 1, characterized in that: A frequency response model of a power system including grid-connected energy storage is constructed, including: Among them, k E is the additional control proportional coefficient of energy storage frequency, T E is the inner loop control response time constant, s is the Laplace operator; ΔP E is the power change delivered by the energy storage system, and Δf is the AC bus frequency.

4. The method according to claim 1, characterized in that: Evaluate the minimum system inertia requirements taking into account frequency characteristics, including, Select the time interval with the smallest fluctuation on the curve. The starting point of the time interval is the disturbance occurrence time point t1, and the end point is the sampling time point t2. Calculate the inertia evaluation result according to the following formula: in, is the average value of inertia in the sampling interval; υ is the number of data in the sampling interval; The sampling time t2 is equal to t n The calculated inertia value at t is t; τ is the initial sampling time of the current time interval; E Csys ' is the equivalent inertia value of the system; υ' is the number of data in the effective sampling time interval.

5. The method according to claim 1, characterized in that: Evaluate the minimum system inertia requirements taking into account frequency characteristics, including, The minimum inertia requirement evaluation value under the power system is calculated as follows: Where ΔP max is the maximum active power disturbance.

6. The method according to claim 1, characterized in that: Evaluate the minimum system inertia requirements taking into account frequency characteristics, including, When multiple resources participate in frequency regulation, the maximum frequency deviation of the power system Δf max The absolute value does not exceed 1Hz, and the grid steady-state frequency deviation Δf ss The absolute value shall not exceed 0.2Hz, and the minimum inertia shall be the larger value of the minimum inertia that meets the above two conditions.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, the steps of the method for evaluating the minimum inertia of the power system considering the frequency response of the grid-connected energy storage are implemented as described in any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the minimum inertia of a power system considering the frequency response of grid-connected energy storage are implemented as described in any one of claims 1 to 6.

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