Method and system for determining aggregated energy storage aggregated frequency support capability and storage medium

Abstract

The application discloses a large-scale energy storage aggregation frequency support capability determination method and system and a storage medium, and relates to the technical field of energy storage. The method comprises the following steps: taking the maximum inertia response power of an energy storage cluster as a target, a first target function of the energy storage cluster is constructed; the inertia response power of the energy storage cluster is the sum of the inertia response powers of each energy storage power station in the energy storage cluster; taking the maximum primary frequency modulation power of the energy storage cluster as a target, a second target function of the energy storage cluster is constructed; the primary frequency modulation power of the energy storage cluster is the sum of the primary frequency modulation powers of each energy storage power station in the energy storage cluster; when the energy storage cluster is running in real time, the maximum inertia response power of the energy storage cluster is obtained according to the first target function; and the maximum primary frequency modulation response power of the energy storage cluster is obtained according to the second target function based on the maximum inertia response power of the energy storage cluster. The application improves the accuracy of the support capability evaluation of the energy storage cluster.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to a method, system, and storage medium for determining the aggregation frequency support capability of large-scale energy storage. Background Technology

[0002] In recent years, with increasingly tense energy conditions and more severe environmental problems, the high proportion of renewable energy power generation has led to a decline in the rotational inertia, power balance maintenance, and system fault resistance capabilities of high-renewable energy power systems. This is due to the large fluctuations and intermittent nature of renewable energy output, and the fact that renewable energy is often connected to the system via power electronic devices. Consequently, the system faces challenges in terms of security, flexibility, and emergency power support. In recent years, energy storage systems have been widely used in all stages of the power system—generation, transmission, distribution, and consumption—due to their bidirectional power capabilities and flexible regulation. On the generation side, energy storage can smooth power output, track planned output, and play a role in peak shaving and valley filling. On the transmission side, energy storage can reduce the investment cost of transmission network construction, improve power quality, and enhance system security. On the distribution side, energy storage can effectively alleviate peak load demand and provide some protection in the event of a fault. During the consumption phase, energy storage assists in the connection of distributed power sources, reducing the peak-valley difference and improving power quality. Applying energy storage systems to all stages of the power grid is an indispensable regulation tool for new power systems dominated by renewable energy. By the end of 2022, China had put into operation 8.7 million kilowatts of new energy storage projects. Among the total installed capacity of new energy storage in China, lithium-ion battery energy storage accounted for 94.5%, compressed air energy storage for 2%, flow battery energy storage for 1.6%, lead-acid (carbon) battery energy storage for 1.7%, and other technologies for 0.2%. In addition, various energy storage technologies such as flywheel, gravity, and sodium-ion have also entered the engineering demonstration stage.

[0003] Battery energy storage technology can convert electrical energy into chemical energy through certain media to store electrical energy, which can then be released when needed. The stored energy can be used as emergency power or to support grid frequency. Energy storage batteries are characterized by fast response speed, strong short-term power throughput, and easy adjustment direction. With the development of science and technology, the performance of various energy storage batteries has been greatly improved, their expected lifespan has gradually increased, battery efficiency has gradually improved, and manufacturing costs have continued to decrease. Adding virtual inertia control and droop control to energy storage converters allows energy storage power stations to participate in inertia response and primary frequency regulation. All these indications suggest that large-scale energy storage to support the grid is the best solution for improving power system stability. However, in high-proportion renewable energy power systems, different grid application scenarios and operating conditions have different requirements for energy storage support. How to efficiently and flexibly utilize energy storage technology faces the technical challenge of accurately assessing the multi-dimensional aggregation support capabilities of energy storage clusters. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and storage medium for determining the frequency support capability of large-scale energy storage aggregation, thereby improving the accuracy of assessing the support capability of energy storage clusters.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for determining the aggregation frequency support capability of large-scale energy storage includes:

[0007] With the goal of maximizing the inertial response power of the energy storage cluster, a first objective function for the energy storage cluster is constructed; the inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster.

[0008] A second objective function for the energy storage cluster is constructed with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster.

[0009] When the energy storage cluster is running in real time, the maximum inertial response power of the energy storage cluster is obtained according to the first objective function; based on the maximum inertial response power of the energy storage cluster, the maximum primary frequency regulation response power of the energy storage cluster is obtained according to the second objective function.

[0010] Optionally, the first objective function is expressed as:

[0011]

[0012] in, N represents the inertial response power of energy storage power station i. V This indicates the number of energy storage power stations participating in inertial response within the energy storage cluster;

[0013] The inertial response power of energy storage power station i is expressed as:

[0014]

[0015] in, T represents the inertial response power of energy storage power station i. E,i f represents the equivalent inertia time constant of energy storage power station i. RoCoF Let i be the frequency change rate of the energy storage power station. This represents the rated active power of the energy storage cluster, and f0 is the rated frequency of the power grid.

[0016] Optionally, the constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the SOC constraint of the energy storage power station.

[0017] Optionally, the second objective function is expressed as:

[0018]

[0019] in, N represents the primary frequency regulation power of energy storage power station i. D This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster;

[0020] The primary frequency regulation power of energy storage power station i is expressed as:

[0021]

[0022] in, Let K represent the primary frequency regulation power of energy storage power station i, Δf be the system frequency deviation, and K be the frequency regulation power of the energy storage power station i. E,i This represents the unit regulating power of energy storage power station i.

[0023] Optionally, the constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints of energy storage, maximum power constraints of energy storage power station, SOC constraints of energy storage power station, start-up state constraints of synchronous generator, frequency regulation capacity constraints of synchronous generator, and transmission power constraints of transmission line.

[0024] This invention discloses a system for determining the frequency support capability of large-scale energy storage aggregation, characterized in that it comprises:

[0025] The first objective function construction module is used to construct the first objective function of the energy storage cluster with the goal of maximizing the inertial response power of the energy storage cluster; the inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster.

[0026] The second objective function construction module is used to construct the second objective function of the energy storage cluster with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster.

[0027] The support capability determination module is used to obtain the maximum inertial response power of the energy storage cluster according to the first objective function when the energy storage cluster is running in real time; and to obtain the maximum primary frequency regulation response power of the energy storage cluster according to the second objective function based on the maximum inertial response power of the energy storage cluster.

[0028] Optionally, the first objective function is expressed as:

[0029]

[0030] in, N represents the inertial response power of energy storage power station i. V This indicates the number of energy storage power stations participating in inertial response within the energy storage cluster;

[0031] The inertial response power of energy storage power station i is expressed as:

[0032]

[0033] in, T represents the inertial response power of energy storage power station i. E,i f represents the equivalent inertia time constant of energy storage power station i. RoCoF Let i be the frequency change rate of the energy storage power station. This represents the rated active power of the energy storage cluster, and f0 is the rated frequency of the power grid.

[0034] Optionally, the second objective function is expressed as:

[0035]

[0036] in, N represents the primary frequency regulation power of energy storage power station i. D This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster;

[0037] The primary frequency regulation power of energy storage power station i is expressed as:

[0038]

[0039] in, Let K represent the primary frequency regulation power of energy storage power station i, Δf be the system frequency deviation, and K be the frequency regulation power of the energy storage power station i. E,i This represents the unit regulating power of energy storage power station i.

[0040] Optionally, the constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the SOC constraint of the energy storage power station.

[0041] The constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints of energy storage, maximum power constraints of energy storage power station, SOC constraints of energy storage power station, start-up state constraints of synchronous generator, frequency regulation capacity constraints of synchronous generator, and transmission power constraints of transmission line.

[0042] The present invention also discloses a computer-readable storage medium storing a computer program, which is executed by a processor to determine the above-described method for determining the frequency support capability of large-scale energy storage aggregation.

[0043] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0044] This invention constructs objective functions for the inertial response power and primary frequency regulation power of an energy storage cluster. When the energy storage power station is running in real time, the problem of evaluating the inertial response capability of the energy storage cluster is transformed into an optimization problem with the goal of maximizing the inertial response power under certain constraints. This yields the maximized inertial response power and the maximized primary frequency regulation power of the energy storage cluster, thereby improving the accuracy of the evaluation of the support capability of the energy storage cluster. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic flowchart of a method for determining the aggregation frequency support capability of large-scale energy storage provided in an embodiment of the present invention;

[0047] Figure 2 This is a schematic diagram of the inertial response power of an energy storage cluster under different disturbances, provided in an embodiment of the present invention.

[0048] Figure 3 This is a schematic diagram of the equivalent inertia time constant of an energy storage cluster under different disturbances, provided in an embodiment of the present invention.

[0049] Figure 4 This is a schematic diagram of the primary frequency regulation power of an energy storage cluster under different disturbances, provided in an embodiment of the present invention.

[0050] Figure 5 This is a schematic diagram of the unit adjustment power of an energy storage cluster under different disturbances provided in an embodiment of the present invention;

[0051] Figure 6 This is a schematic diagram illustrating the adjustable frequency regulation time of an energy storage cluster under different disturbances, provided in an embodiment of the present invention.

[0052] Figure 7 This is a schematic diagram of a system structure for determining the frequency support capability of large-scale energy storage aggregation, provided in an embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] The purpose of this invention is to provide a method for determining the frequency support capability of large-scale energy storage aggregation, thereby improving the accuracy of assessing the support capability of energy storage clusters.

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] like Figure 1 As shown in the figure, this embodiment provides a method for determining the frequency support capability of large-scale energy storage aggregation, including:

[0058] Step 101: Construct the first objective function of the energy storage cluster with the goal of maximizing the inertial response power of the energy storage cluster; the inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster.

[0059] Step 102: Construct a second objective function for the energy storage cluster, with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster.

[0060] The inertial response power index of the energy storage cluster is determined by the superposition of the inertial response power of the energy storage power stations participating in the inertial response. The inertial response power of the energy storage cluster is expressed as:

[0061]

[0062] in, This represents the inertial response power of the energy storage cluster. N represents the inertial response power of energy storage power station i. V This indicates the number of energy storage power stations participating in the inertial response within the energy storage cluster.

[0063] The inertial response power of energy storage power station i is expressed as:

[0064]

[0065] in, T represents the inertial response power of energy storage power station i. E,i f represents the equivalent inertia time constant (virtual synchronous machine inertia time constant) of energy storage power station i. RoCoF Let i be the frequency change rate of the energy storage power station. This represents the rated active power of the energy storage cluster, and f0 is the rated frequency of the power grid.

[0066] The inertia-supported power of the energy storage power station i is subject to the physical constraints of the energy storage device, and satisfies the following expression for the power adjustment constraint:

[0067] in, This refers to the adjustable power of energy storage power station i.

[0068] The equivalent inertia time constant index of energy storage clusters is:

[0069]

[0070] Among them, T E This represents the equivalent inertia time constant of the energy storage cluster. The rated active power of energy storage power station j, The rated active power of energy storage power station i.

[0071] Energy storage power stations employ droop control to simulate the process of synchronous power generation adjusting steady-state power following the prime mover, thereby reducing the final frequency deviation and enabling the system frequency to reach a new steady state. The unit active power frequency regulation coefficient of an energy storage power station... The expression is:

[0072]

[0073] Where Δf is the system frequency deviation, and ΔP i Let be the change in active power of energy storage power station i. This is the rated power of energy storage power station i.

[0074] Unit regulation power K of energy storage power station i E,i The expression is:

[0075]

[0076] The primary frequency regulation power index of the energy storage cluster is obtained by summing the primary frequency regulation power of each energy storage power station. The primary frequency regulation power of the energy storage cluster is expressed as:

[0077]

[0078] in, This represents the primary frequency regulation power of the energy storage cluster. N represents the primary frequency regulation power of energy storage power station i. D This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster.

[0079] The primary frequency regulation power of energy storage power station i is expressed as:

[0080]

[0081] in, Let K represent the primary frequency regulation power of energy storage power station i, Δf be the system frequency deviation, and K be the frequency regulation power of the energy storage power station i. E,i This represents the unit regulating power of energy storage power station i.

[0082] Considering the coupling relationship between inertial response and primary frequency modulation, The power constraint is expressed as:

[0083] Online evaluation indicators for the primary frequency regulation capability of energy storage power stations include the overall unit regulation power index of the energy storage cluster, the maximum primary frequency regulation power index of the energy storage power station, and the adjustable time index of the energy storage cluster:

[0084] (1) Assume there are N energy storage clusters D If an energy storage power station participates in inertial response through droop control, then the unit regulation power index K of the energy storage cluster will be... E K, an energy storage power station that performs primary frequency regulation E,i The summation yields the overall unit regulation power index of the energy storage cluster:

[0085] K E The unit regulating power of the energy storage cluster.

[0086] (2) Maximum power index P of primary frequency regulation of energy storage power station PFR,max It is obtained by accumulating the energy storage units that perform one frequency regulation:

[0087]

[0088] in,

[0089] (3) Adjustable time index t of energy storage cluster PFR The working time t for primary frequency regulation from energy storage power station i PFR,i for:

[0090]

[0091] The minimum discharge time of all energy storage power stations is taken as the primary frequency regulation adjustable time t of the energy storage cluster. PFR .

[0092] t PFR =min(t) PFR,1 ,t PFR,2 ...t PFR,ND ).

[0093] Among them, t PFR,i Let i be the frequency regulation adjustable time of energy storage power station i, where i takes values ​​from 1 to N. D positive integers, Let η be the current power of energy storage power station i. c The charging power for the energy storage power station, η d E represents the discharge power of the energy storage power station. d,i E represents the remaining discharge capacity of energy storage power station i.c,i This represents the remaining charging capacity of energy storage station i.

[0094] Based on the control method of inertial response of energy storage power stations, a large-scale energy storage aggregation inertial support capability assessment model is established. The large-scale energy storage aggregation inertial support capability assessment model includes a first objective function and a second objective function.

[0095] In real-time operation, when the system load changes ΔP D The inertial response power of the energy storage power station is The objective function of the evaluation model is the sum of the inertial response power of all energy storage power stations.

[0096] The first objective function is expressed as:

[0097]

[0098] in, N represents the inertial response power of energy storage power station i. V This indicates the number of energy storage power stations participating in the inertial response within the energy storage cluster.

[0099] The constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the SOC constraint of the energy storage power station.

[0100] The energy storage inertia time constant constraint is expressed as:

[0101]

[0102] Among them, T E,i This represents the equivalent inertia time constant of energy storage power station i. Let i represent the minimum inertia time constant of energy storage power station i. This represents the maximum inertia time constant of energy storage power station i.

[0103] The maximum power constraint of an energy storage power station is expressed as:

[0104]

[0105]

[0106]

[0107]

[0108] Where, N G f is the number of synchronous generators operating in the energy storage cluster. RoCoF S is the rate of change of the system frequency at the instant the disturbance occurs; sys The total capacity of the operating synchronous generator and energy storage power station; Tsys T is the system's equivalent inertia time constant; E,i The inertia time constant of the energy storage power station; T represents the rated power of energy storage power station i; r Let r be the inertia time constant of the synchronous generator; f0 is the rated power of the synchronous generator r; f0 is the rated frequency of the system. Let be the energy storage inertia response power of energy storage power station i.

[0109] The state of charge (SOC) constraint of an energy storage power station is expressed as follows:

[0110] SOC min ≤SOC i ≤SOC max .

[0111] Among them, SOC i The State of Charge (SOC) represents the state of charge of energy storage station i. min State of Charge (SOC) represents the minimum state of charge of an energy storage power station. max This indicates the maximum state of charge of the energy storage power station.

[0112] By combining the four formulas for the maximum power constraint of the energy storage power station, we obtain:

[0113]

[0114] Among them, inertial response power Inertia time constant T E,i All are optimization variables. Multiplying the variables to be optimized in the previous iterations makes this constraint nonlinear. The binary extension method is then used to linearize this constraint. Using 2... X Discrete unit for variable T E,i Discretize the data, taking X = 12, as shown below:

[0115]

[0116] in, z x It is a 0-1 variable.

[0117] Formula Substitution get:

[0118]

[0119] in, satisfy:

[0120]

[0121] Among them, v x As an intermediate variable, This refers to the adjustable power of energy storage power station i.

[0122] The formula Substitution This linearizes the nonlinear constraints.

[0123] When the energy storage power station is running in real time, based on the evaluation results of the energy storage cluster's inertia support capability, the problem of evaluating the primary frequency regulation capability of the energy storage cluster is transformed into an optimization problem with the objective of maximizing the primary frequency regulation response power under certain constraints.

[0124] When the energy storage power station is running in real time, based on the evaluation results of the energy storage cluster's inertia support capability, the problem of evaluating the primary frequency regulation capability of the energy storage cluster is transformed into an optimization problem with the objective of maximizing the primary frequency regulation response power under certain constraints.

[0125] When the system load changes ΔP D Change in primary frequency regulation response power of energy storage power station The objective function is the sum of the primary frequency regulation response power of each energy storage power station.

[0126] The second objective function is expressed as:

[0127]

[0128] in, N represents the primary frequency regulation power of energy storage power station i. D This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster.

[0129] The constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints of energy storage, maximum power constraints of energy storage power station, SOC constraints of energy storage power station, start-up state constraints of synchronous generator, frequency regulation capacity constraints of synchronous generator, and transmission power constraints of transmission line.

[0130] The power balance constraint is expressed as:

[0131]

[0132] Where, N D N represents the number of energy storage power stations participating in primary frequency regulation. G The number of synchronous generators in operation. Let i be the primary frequency regulation power of energy storage power station i; Let r be the primary frequency regulation power of the synchronous generator.

[0133] The constraint of the primary frequency regulation coefficient for energy storage is expressed as:

[0134]

[0135] in,

[0136] Let be the minimum primary frequency regulation coefficient of energy storage power station i. is the maximum primary frequency regulation coefficient of energy storage power station i.

[0137] The maximum power constraint of an energy storage power station is expressed as:

[0138]

[0139]

[0140]

[0141]

[0142] in, This represents the active power frequency regulation coefficient per unit of the energy storage unit. K represents the rated power of the energy storage power station. G,r The unit adjustment power for the synchronous machine.

[0143] The SOC constraint of an energy storage power station is expressed as:

[0144]

[0145] Among them, SOC i State of charge (SOC) of energy storage power station i. min and SOC max These represent the minimum and maximum states of charge of the energy storage power station, respectively, T. E,j Δf represents the equivalent inertia time constant of energy storage power station j. max Indicates the maximum frequency deviation. This indicates the rated capacity of the energy storage power station.

[0146] The start-up state constraints of a synchronous generator are expressed as follows:

[0147]

[0148] Among them, V r V represents the state variable of the synchronous generator. r 0 This indicates the initial power-on state of the synchronous machine.

[0149] The frequency regulation capacity constraint of a synchronous generator is expressed as follows:

[0150]

[0151] in, This is the rated capacity of the synchronous generator. This indicates the frequency regulation capacity of the synchronous generator r.

[0152] The power transmission constraint of a transmission line is expressed as:

[0153]

[0154] P represents the maximum transmission power of the transmission line. L To transmit power to power transmission lines.

[0155] Linearization of the primary frequency regulation power constraint for energy storage is performed, specifically including:

[0156] Solving the four formulas for the maximum power constraint of energy storage power stations simultaneously, we get:

[0157]

[0158] Among them, primary frequency modulation power Energy storage primary frequency regulation coefficient All of these are optimization quantities. Multiplying the previous generation of variables to be optimized makes this constraint a nonlinear constraint.

[0159] K r Let r be the primary frequency regulation coefficient of the synchronous generator.

[0160] The constraint is linearized using the binary extension method.

[0161] Use 2 X Each discrete unit for variables Discretize the expression, removing X = 12, as shown in the following equation:

[0162]

[0163] in, Then It can be written in the following form:

[0164]

[0165] in, satisfy:

[0166]

[0167] The formula Substitution This linearizes the nonlinear constraints.

[0168] Step 103: When the energy storage cluster is running in real time, the maximum inertial response power of the energy storage cluster is obtained according to the first objective function; based on the maximum inertial response power of the energy storage cluster, the maximum primary frequency regulation response power of the energy storage cluster is obtained according to the second objective function.

[0169] The following specific example illustrates a method for determining the aggregation frequency support capability of large-scale energy storage according to the present invention.

[0170] The proposed method for assessing the frequency support capability of large-scale energy storage aggregation was applied to the improved IEEE RTS-24 system. The improved IEEE RTS-24 system has 12 conventional power sources, with node 11 connected to a wind farm and 6 energy storage stations. At a certain moment, the system load was 3098 MW, and the wind farm's output power was 428 MW. Information on each energy storage station is shown in Table 1, and real-time information on the synchronous generators is shown in Table 2.

[0171] Table 1 Information on each energy storage power station

[0172]

[0173]

[0174] Table 2 Synchronous Unit Information

[0175]

[0176] The inertial response power of the energy storage cluster is evaluated in real time under different disturbance magnitudes, as shown in the attached figure. Figure 2 As shown, the inertial response power of the energy storage cluster increases linearly with the increase of disturbance power, from 2.723MW when the disturbance power accounts for 0.01% of the total load to 36.3MW when the disturbance power accounts for 0.15% of the total load.

[0177] The equivalent inertia time constant of the energy storage cluster is evaluated in real time under different disturbance magnitudes, as shown in the attached figure. Figure 3 As shown, with the increase of disturbance power, f RoCoF The increase is due to the energy storage power station 2 reducing the inertia time constant to meet the active power constraint. The equivalent inertia time constant of the energy storage cluster decreases from 7.03s when the disturbance power accounts for 0.01% of the total load to 6.18s when the disturbance power accounts for 0.15% of the total load.

[0178] The primary frequency regulation power of the energy storage cluster is evaluated in real time under different disturbance magnitudes, as shown in the attached figure. Figure 4 As shown, with the increase of disturbance power, Δf max As the load increased, the primary frequency regulation power of the energy storage cluster increased from 9.54MW when the disturbance power accounted for 0.01% of the total load to 305MW when the disturbance power accounted for 0.15% of the total load.

[0179] Real-time assessment of the unit regulating power of the energy storage cluster under different disturbance magnitudes is shown in the attached figure. Figure 5As shown, when the disturbance power accounts for 0.01-0.07 of the load power, each energy storage station can perform primary frequency regulation with the maximum unit regulation power. When the disturbance power accounts for 0.08 of the load power, the primary frequency regulation power of energy storage station 4 is limited by the maximum power, and its unit regulation power begins to decrease as the disturbance power increases, resulting in a decrease in the unit regulation power of the energy storage cluster.

[0180] The real-time evaluation of the adjustable frequency regulation time of the energy storage cluster under different disturbance magnitudes is shown in the attached figure. Figure 6 As shown, with the increase of disturbance power, the discharge power of the energy storage power station increases, and the adjustable time of primary frequency regulation of the energy storage cluster decreases from 0.45h when the disturbance power accounts for 0.01 of the total load to 0.184h when the disturbance power accounts for 0.15 of the total load.

[0181] The results of the implementation case studies show that the proposed method can be used to assess the aggregation frequency support capability of large-scale energy storage clusters, which can help with the real-time dispatch of new power systems.

[0182] Example 2

[0183] like Figure 7 As shown, this embodiment provides a system for determining the frequency support capability of large-scale energy storage aggregation, comprising:

[0184] The first objective function construction module 201 is used to construct the first objective function of the energy storage cluster with the goal of maximizing the inertial response power of the energy storage cluster; the inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster.

[0185] The second objective function construction module 202 is used to construct a second objective function for the energy storage cluster with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster.

[0186] The support capability determination module 203 is used to obtain the maximum inertial response power of the energy storage cluster according to the first objective function when the energy storage cluster is running in real time; and to obtain the maximum primary frequency regulation response power of the energy storage cluster according to the second objective function based on the maximum inertial response power of the energy storage cluster.

[0187] The first objective function is expressed as:

[0188]

[0189] in, N represents the inertial response power of energy storage power station i. V This indicates the number of energy storage power stations participating in inertial response within the energy storage cluster;

[0190] The inertial response power of energy storage power station i is expressed as:

[0191]

[0192] in, T represents the inertial response power of energy storage power station i. E,i f represents the equivalent inertia time constant of energy storage power station i. RoCoF Let i be the frequency change rate of the energy storage power station. This represents the rated active power of the energy storage cluster, and f0 is the rated frequency of the power grid.

[0193] The second objective function is expressed as:

[0194]

[0195] in, N represents the primary frequency regulation power of energy storage power station i. D This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster;

[0196] The primary frequency regulation power of energy storage power station i is expressed as:

[0197]

[0198] in, Let K represent the primary frequency regulation power of energy storage power station i, Δf be the system frequency deviation, and K be the frequency regulation power of the energy storage power station i. E,i This represents the unit regulating power of energy storage power station i.

[0199] The constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the SOC constraint of the energy storage power station.

[0200] The constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints of energy storage, maximum power constraints of energy storage power station, SOC constraints of energy storage power station, start-up state constraints of synchronous generator, frequency regulation capacity constraints of synchronous generator, and transmission power constraints of transmission line.

[0201] Example 3

[0202] This embodiment also provides a computer-readable storage medium storing a computer program, which is executed by a processor using the method for determining the frequency support capability of large-scale energy storage aggregation as described in Embodiment 1.

[0203] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0204] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the frequency support capability of large-scale energy storage aggregation, characterized in that, include: The first objective function of the energy storage cluster is constructed with the goal of maximizing the inertial response power of the energy storage cluster. The inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster. A second objective function for the energy storage cluster is constructed with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster. When the energy storage cluster is running in real time, the maximum inertial response power of the energy storage cluster is obtained according to the first objective function; based on the maximum inertial response power of the energy storage cluster, the maximum primary frequency regulation response power of the energy storage cluster is obtained according to the second objective function. The first objective function is expressed as: ； in, Indicates energy storage power station Inertial response power, This indicates the number of energy storage power stations participating in inertial response within the energy storage cluster; Energy storage power station The inertial response power is expressed as: ； in, Indicates energy storage power station Inertial response power, Indicates energy storage power station The equivalent inertia time constant, For energy storage power stations The rate of change of frequency, This indicates the rated active power of the energy storage cluster. The rated frequency of the power grid; The constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the energy storage power station's... constraint; The second objective function is expressed as: ； in, Indicates energy storage power station The primary frequency modulation power, This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster; Energy storage power station The primary frequency modulation power is expressed as: ； in, For system frequency deviation, For energy storage power stations The unit regulating power; The constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints for energy storage, maximum power constraints for energy storage power stations, and energy storage power station constraints. Constraints include synchronous generator start-up status constraints, synchronous generator frequency regulation capacity constraints, and transmission line power transmission constraints.

2. A system for determining the frequency support capability of large-scale energy storage aggregation, characterized in that, include: The first objective function construction module is used to construct the first objective function of the energy storage cluster with the goal of maximizing the inertial response power of the energy storage cluster. The inertial response power of the energy storage cluster is the sum of the inertial response power of each energy storage power station in the energy storage cluster. The second objective function construction module is used to construct the second objective function of the energy storage cluster with the goal of maximizing the primary frequency regulation power of the energy storage cluster; the primary frequency regulation power of the energy storage cluster is the sum of the primary frequency regulation power of each energy storage power station in the energy storage cluster. The support capability determination module is used to obtain the maximum inertial response power of the energy storage cluster according to the first objective function when the energy storage cluster is running in real time; and to obtain the maximum primary frequency regulation response power of the energy storage cluster according to the second objective function based on the maximum inertial response power of the energy storage cluster. The first objective function is expressed as: ； in, Indicates energy storage power station Inertial response power, This indicates the number of energy storage power stations participating in inertial response within the energy storage cluster; Energy storage power station The inertial response power is expressed as: ； in, Indicates energy storage power station Inertial response power, Indicates energy storage power station The equivalent inertia time constant, For energy storage power stations The rate of change of frequency, This indicates the rated active power of the energy storage cluster. The rated frequency of the power grid; The second objective function is expressed as: ； in, Indicates energy storage power station The primary frequency modulation power, This indicates the number of energy storage power stations participating in primary frequency regulation within the energy storage cluster; Energy storage power station The primary frequency modulation power is expressed as: ； in, For system frequency deviation, For energy storage power stations The unit regulating power; The constraints of the first objective function include the inertia time constant constraint of the energy storage power station, the maximum power constraint of the energy storage power station, and the energy storage power station's... constraint; The constraints of the second objective function include power balance constraints, primary frequency regulation coefficient constraints for energy storage, maximum power constraints for energy storage power stations, and energy storage power station constraints. Constraints include synchronous generator start-up status constraints, synchronous generator frequency regulation capacity constraints, and transmission line power transmission constraints.

3. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the method for determining the frequency support capability of large-scale energy storage aggregation as described in claim 1.

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