A string type energy storage layered cooperative control method and related device
By employing a hierarchical collaborative control method based on grid frequency deviation prediction, and using spectral clustering algorithm and optimization problem solving, the problems of control rigidity and lack of decision-making in string energy storage systems in grid frequency regulation are solved, achieving efficient and economical grid frequency regulation and string collaborative control.
Patent Information
- Application Number
- CN202610900226.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-22
- Publication Date
- 2026-07-24
AI Technical Summary
Existing string energy storage systems suffer from rigid control architecture, lack of forward-looking decision-making, and single optimization objectives in grid frequency regulation, resulting in insufficient frequency regulation capability and reduced system operating economy.
A hierarchical collaborative control method based on power grid frequency deviation prediction is adopted. Through dynamic grouping using spectral clustering algorithm and optimization problem solving, accurate allocation and collaborative control of strings are achieved.
It improves the adaptability and foresight of string energy storage systems, enhances overall frequency regulation performance and asset utilization, and achieves efficient and economical grid frequency regulation.
Smart Images
Figure CN122456602A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of collaborative control technology and relates to a hierarchical collaborative control method and related devices for string energy storage. Background Technology
[0002] With the increasing penetration of renewable energy, the frequency stability of the power grid faces severe challenges. Energy storage systems, especially electrochemical energy storage power stations, have become a key means to support power grid frequency regulation due to their fast and accurate power response capabilities. String energy storage systems integrate a large number of battery strings in parallel, offering advantages such as flexible configuration, strong scalability, and easy modular maintenance.
[0003] In achieving efficient, reliable, and coordinated operation of string energy storage in complex and continuous frequency regulation tasks, the following significant defects and shortcomings still exist: The control architecture is rigid and lacks task adaptability: In existing hierarchical or clustered control architectures, the "groups" or "clusters" are usually pre-divided based on physical connections or fixed topologies, and remain unchanged throughout the operating cycle once set. This static grouping cannot adapt to the ever-changing frequency regulation requirements of the power grid and the dynamic differences in the state of each string. Fixed grouping may lead to some clusters having excess capacity while others have insufficient capacity during specific periods, forming a "weakest link" effect, and the overall frequency regulation potential cannot be optimally activated.
[0004] The lack of foresight in decision-making easily leads to state imbalances: Most existing control methods are reactive, meaning they make decisions based on current commands and states. This lacks prediction of future trends in frequency regulation tasks. When frequency regulation commands in the same direction occur consecutively, the entire station's State of Charge (SOC) can quickly concentrate at one end, shortening the sustainable frequency regulation time window and reducing the system's economic efficiency due to frequent, expensive, non-frequency regulation-related charge-discharge balancing operations. Essentially, this is a disconnect between control and energy management.
[0005] The optimization objectives are singular and the coordination is not adequately considered: existing optimization allocation algorithms mostly take the achievement of total power command tracking as the primary or only objective. Although they consider constraints such as SOC balance and efficiency, they lack in-depth modeling of the inherent characteristics of the "coordination" series system. This results in some units being in a high-load state for a long time and aging faster, forming a "lifetime difference" with low-load units, which is not conducive to the overall health of power plant assets.
[0006] In summary, the existing string energy storage frequency regulation system has a relatively crude control over the strings and cannot achieve precise control of the strings in a hierarchical and coordinated manner. Summary of the Invention
[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hierarchical coordinated control method and related device for string energy storage, which can perform precise hierarchical coordinated control of strings.
[0008] To achieve the above objectives, this invention discloses a hierarchical coordinated control method for string energy storage, comprising: Get the current time The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ; Based on the aforementioned whole-site string Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; The real-time status of all strings within the frequency modulation group is obtained. Based on the real-time status of all strings within the frequency modulation group, the total power command of the frequency modulation group issued by the power grid AGC (Automatic Generation Control) system is used. As an equality constraint, with the goal of maximizing the overall efficiency of the frequency modulation group, an optimization problem is constructed, and the optimization problem is solved to obtain the optimal allocation instructions for each string in the frequency modulation group; The output frequency of the corresponding string in the frequency modulation group is controlled based on the optimal allocation instruction of each string in the frequency modulation group.
[0009] Furthermore, the whole-site string in Cumulative frequency modulation energy reference at any time for:
[0010] in, For the current moment The level component of the improved Holt-Winters prediction model; For the current moment The trend component of the improved Holt-Winters forecasting model; for Seasonal components of the improved Holt-Winters forecasting model for time; The length of the seasonal cycle; This is the midpoint of the optimal state of charge for frequency modulation. To predict the step size; This refers to the rated frequency regulation power capacity of the power station. For the current moment The weighted average state of charge of all strings in the station.
[0011] Furthermore, the current moment Dynamic frequency modulation coordination matrix The Middle Line 1 The elements of the column represent the current time. The The string and the first Dynamic coordination degree of each string ,in, for:
[0012] in, For the first A static attribute vector of each string; For the first A static attribute vector of each string; The Gaussian kernel width parameter; Indicates the current time The The current available energy capacity of each string; Indicates the current time The The current available energy capacity of each string; For the current moment The The degree of matching between each string and the predicted total demand; For the current moment The The degree of matching between each string and the predicted total demand; For the current moment The The degree of matching between each string and the predicted total demand; () represents an exponential function; min() is the minimum value function; max() is the maximum value function; cos() is the cosine function.
[0013] Furthermore, at the current moment The The degree of matching between each string and the predicted total demand for:
[0014] in, For the prediction period Absolute value of total internal energy demand , For the prediction period. Furthermore, the optimization problem is:
[0015] in, This refers to the average power distribution of strings within an FM group. ; This represents the number of strings within the FM group; The loss coefficient function is related to SOC; The weighting coefficient for effectiveness; This is the weighting coefficient for losses; A coefficient reflecting the battery loss characteristics under different SOCs; The maximum allowable imbalance threshold; For the first Strings ; For the first The current lower limit of power for each string; For the first Current efficiency estimates for each string group; For the first The SOC value of each string; For the first The current power of each string; This represents the q-th frequency modulation group.
[0016] Furthermore, the process of controlling the output frequency of the corresponding string within the frequency modulation group based on the optimal allocation instruction of each string in the frequency modulation group is as follows: The instantaneous correction amount for determining the optimal allocation instruction for each string in the frequency modulation group; The final execution instruction for each string in the frequency modulation group is calculated based on the optimal allocation instruction for each string in the frequency modulation group and the real-time correction amount of the optimal allocation instruction for each string in the frequency modulation group. The power electronic converter of the corresponding string is controlled according to the final execution command of each string in the frequency modulation group to adjust the output power of the string.
[0017] Furthermore, in the FM group, the first Instantaneous correction of the optimal allocation instruction for each string. for:
[0018] in, Table t, time 1 The difference between the optimal allocation instruction for each string and the power measurement. ; For the first The set of neighbors of each string; The length of the sliding integral window; This is the integral gain coefficient; It is a time constant; For the current moment The The string and the first The dynamic coordination degree of each group string; The first time at time t Power measurements of each string; The first time at time t Power measurements of each string; For the first The optimal allocation instruction for each string.
[0019] This invention discloses a string-type energy storage hierarchical collaborative control system, comprising: The acquisition module is used to obtain the current time. The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ; The clustering module is used to cluster based on the whole-site group string. Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; The optimization module is used to obtain the real-time status of all strings within the frequency modulation group, and based on the real-time status of all strings within the frequency modulation group, calculate the total power command of the frequency modulation group issued by the power grid AGC system. As an equality constraint, with the goal of maximizing the overall efficiency of the frequency modulation group, an optimization problem is constructed, and the optimization problem is solved to obtain the optimal allocation instructions for each string in the frequency modulation group; The control module is used to control the output frequency of the corresponding string in the frequency modulation group based on the optimal allocation instruction of each string in the frequency modulation group.
[0020] This invention discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the string energy storage hierarchical coordinated control method.
[0021] The present invention discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the string energy storage hierarchical collaborative control method.
[0022] The present invention has the following beneficial effects: In specific operation, the string energy storage hierarchical collaborative control method and related devices described in this invention are based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time This invention employs a spectral clustering algorithm to cluster all station strings, resulting in several frequency modulation groups. This approach demonstrates strong adaptability and a degree of foresight. Simultaneously, the invention utilizes the total power command of the frequency modulation groups issued by the power grid AGC system. With equality constraints as the constraint, and aiming to maximize the overall efficiency of the frequency modulation group, an optimization problem is constructed to take into account the overall situation of the power station. Finally, the optimization problem is solved, and the output frequency of the string is controlled according to the solution, so as to achieve the purpose of precise control of the string in a hierarchical and coordinated manner. It is highly practical. Attached Figure Description
[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system structure diagram of the present invention. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0026] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.
[0027] Example 1 refer to Figure 1 The string energy storage hierarchical collaborative control method of the present invention includes the following steps: 1) Get the current time The frequency deviation time series of the power grid point of common coupling, based on the current time. The frequency deviation time series of the power grid point of common coupling is used to predict the frequency deviation of the entire station string at the power grid point of common coupling. Cumulative frequency modulation energy reference at any time ; Step 1) is as follows: 11) Obtain the frequency deviation time series of the power grid point of common coupling; Real-time acquisition of frequency measurements at the power grid point of common coupling ,calculate Rated frequency of the point of common coupling with the power grid per-unit deviation This is used to form a frequency deviation time series, and at the same time, the real-time state of charge of all strings in the power grid is collected. and rated capacity .
[0028] At the beginning of each forecast period Based on the latest historical frequency deviation data, the three core components of the improved Holt-Winters forecasting model are updated online, namely the horizontal components. Trend components and seasonal component of demand Among them, the horizontal component The current baseline used to characterize the frequency deviation sequence; trend component Used to characterize the changing trend of frequency deviation; seasonal component of demand Used to characterize periodic fluctuation components similar to historical contemporaneous periods, where the horizontal component at time t... Trend components and seasonal component of demand They are respectively:
[0029] in, The smoothing coefficient is obtained through training with historical data; The length of the seasonal cycle is determined based on the main period of frequency fluctuations.
[0030] 12) Calculate the system's average state: Calculate the current time... Weighted average state of charge of all strings at the station .
[0031] 13) Predict the entire site's string sequence in Cumulative frequency modulation energy reference at any time for:
[0032] in, , For the current moment The level component of the improved Holt-Winters prediction model; For the current moment The trend component of the improved Holt-Winters forecasting model; for Seasonal components of the improved Holt-Winters forecasting model for time; This is the midpoint of the optimal state of charge for frequency modulation. To predict the step size; This refers to the rated frequency regulation power capacity of the power station.
[0033] 2) Based on the aforementioned whole-site string in Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; The specific operation of step 2) is as follows: 21) Calculate the current time. The The degree of matching between each string and the predicted total demand for:
[0034] in, For the prediction period Absolute value of total internal energy demand , For the prediction period; Indicates the current time The The current available energy capacity of each string. .
[0035] 22) Construct the current moment Dynamic frequency modulation coordination matrix The dynamic frequency modulation coordination degree matrix The Middle Line 1 The elements of the column represent the first... The string and the first The string at the current time Dynamic synergy , for:
[0036] in, For the first A static attribute vector of each string; For the first A static attribute vector of each string; The Gaussian kernel width parameter; Indicates the current time The The current available energy capacity of each string; For the current moment No. The degree of matching between each string and the predicted total demand; For the current moment No. The degree of matching between each string and the predicted total demand; () represents an exponential function; min() is the minimum value function; max() is the maximum value function; cos() is the cosine function.
[0037] 23) The current time Dynamic frequency modulation coordination matrix Dynamic grouping was performed using a spectral clustering algorithm to obtain several frequency modulation groups. Each frequency modulation group is assigned a group controller.
[0038] 3) Obtain the real-time status of all strings within the frequency modulation group, and based on the real-time status of all strings within the frequency modulation group, use the total power command of the frequency modulation group issued by the power grid AGC system. To constrain equality, an optimization problem is constructed with the goal of maximizing the overall efficiency of the FM group. Solving this optimization problem yields the optimal allocation instructions for each string in the FM group. ; The specific operation of step 3) is as follows: 31) The group controller acquires the real-time status of all strings within the FM group, the real-time status including the current power lower limit of the string. Current efficiency estimates and SOC value .
[0039] 32) Construction optimization problem: Total power command issued by the power grid AGC system to the group controller With equality constraints in place, and aiming to maximize the overall efficiency of the group, we construct the following optimization problem:
[0040] in, This refers to the average power distribution of strings within an FM group. , The loss coefficient function is related to SOC; The weighting coefficient for effectiveness; This is the weighting coefficient for losses; A coefficient reflecting the battery loss characteristics under different SOCs; The maximum allowable imbalance threshold; For the first The current power of each string.
[0041] 33) Solve the optimization problem to obtain the optimal allocation instructions for each string in the frequency modulation group. .
[0042] The optimal allocation instruction for each string in the FM group. The message is sent to the local controller of the string within the frequency modulation group.
[0043] 4) Based on the optimal allocation instructions for each string in the frequency modulation group. Control the output frequency of the corresponding string within the FM group; The specific operation of step 4) is as follows: 41) Each string local controller acquires and broadcasts the real-time power measurement value of its own node. Each string local controller acquires the real-time power measurement values of adjacent nodes.
[0044] 42) Obtain the optimal allocation instruction for each string in the FM group. The instantaneous correction amount, of which the first in the frequency modulation group Optimal allocation instructions for each string real-time correction amount for:
[0045] in, , For the first The set of neighbors of a string. The length of the sliding integration window. This is the integral gain coefficient; It is a time constant; For time t, the first Power measurements of each string; For time t, the first Power measurements of each string.
[0046] 43) Calculate the final execution instruction for each string in the FM group, where the instruction for the first string in the FM group is... The final execution instruction for each string is .
[0047] 44) Control the power electronic converter of each string according to the final execution instruction of each string to adjust the output power of the string.
[0048] This invention employs a spectral clustering algorithm to cluster all strings in the power station to improve the system's adaptability. In addition, by constructing an optimization problem, the system considers the overall power station situation and achieves precise hierarchical and coordinated control of the strings. This enables the string energy storage system to respond to the grid frequency regulation demand in a highly coordinated, adaptive, and efficient manner, thereby significantly improving the overall frequency regulation performance and asset utilization.
[0049] Example 2 refer to Figure 2 The string-type energy storage hierarchical collaborative control system of the present invention includes: The acquisition module is used to obtain the current time. The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ,in, Indicates a time period; The clustering module is used to cluster based on the whole-site group string. Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; The optimization module is used to obtain the real-time status of all strings within the frequency modulation group, and based on the real-time status of all strings within the frequency modulation group, calculate the total power command of the frequency modulation group issued by the power grid AGC system. As an equality constraint, with the goal of maximizing the overall efficiency of the frequency modulation group, an optimization problem is constructed, and the optimization problem is solved to obtain the optimal allocation instructions for each string in the frequency modulation group; The control module is used to control the output frequency of the corresponding string in the frequency modulation group based on the optimal allocation instruction of each string in the frequency modulation group.
[0050] The module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in each embodiment of this application can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.
[0051] Example 3 A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the string energy storage hierarchical coordinated control method, for example, including: obtaining the current time. The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ,in, Indicates a time period; based on the entire site string in Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix A spectral clustering algorithm is used to cluster all the strings in the station, resulting in several frequency modulation groups. The real-time status of all strings within each frequency modulation group is obtained. Based on the real-time status of all strings within the frequency modulation group, the total power command of the frequency modulation group issued by the power grid AGC system is used. To constrain equality and maximize the overall performance of the frequency modulation group, an optimization problem is constructed. Solving this problem yields the optimal allocation instructions for each string in the frequency modulation group. Based on these optimal allocation instructions, the output frequency of the corresponding string within the frequency modulation group is controlled. The memory may include main memory, such as high-speed random access memory, or it may also include non-volatile memory.
[0052] Example 4 A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the string energy storage hierarchical coordinated control method, for example including: obtaining the current time. The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time Based on the aforementioned whole-site string in Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix ,in, Indicates a time period; based on the current time. Dynamic frequency modulation coordination matrix A spectral clustering algorithm is used to cluster all the strings in the station, resulting in several frequency modulation groups. The real-time status of all strings within each frequency modulation group is obtained. Based on the real-time status of all strings within the frequency modulation group, the total power command of the frequency modulation group issued by the power grid AGC system is used. To constrain equality and maximize the overall performance of the FM group, an optimization problem is constructed. Solving this problem yields the optimal allocation instructions for each string in the FM group. Based on these optimal allocation instructions, the output frequency of the corresponding string within the FM group is controlled. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include read-only memory (ROM), hard disk, flash memory, optical disk, magnetic disk, etc.
[0053] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.
[0054] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.
[0055] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A hierarchical collaborative control method for string energy storage, characterized in that, include: Get the current time The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ,in, Indicates a time period; Based on the aforementioned whole-site string Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; Obtain the real-time status of all strings within the frequency modulation group, and based on the real-time status of all strings within the frequency modulation group, use the total power command of the frequency modulation group issued by the power grid AGC system. As an equality constraint, with the goal of maximizing the overall efficiency of the frequency modulation group, an optimization problem is constructed, and the optimization problem is solved to obtain the optimal allocation instructions for each string in the frequency modulation group; The output frequency of the corresponding string in the frequency modulation group is controlled based on the optimal allocation instruction of each string in the frequency modulation group.
2. The hierarchical coordinated control method for string energy storage according to claim 1, characterized in that, The entire site is in Cumulative frequency modulation energy reference at any time for: in, For the current moment The level component of the improved Holt-Winters prediction model; For the current moment The trend component of the improved Holt-Winters forecasting model; for Seasonal components of the improved Holt-Winters forecasting model for time; The length of the seasonal cycle; This is the midpoint of the optimal state of charge for frequency modulation. To predict the step size; This refers to the rated frequency regulation power capacity of the power station. For the current moment The weighted average state of charge of all strings in the station.
3. The hierarchical coordinated control method for string energy storage according to claim 1, characterized in that, Current moment Dynamic frequency modulation coordination matrix The Middle Line number The elements of the column represent the current time. The The string and the first Dynamic coordination degree of each string ,in, for: in, For the first A static attribute vector of each string; For the first A static attribute vector of each string; The Gaussian kernel width parameter; Indicates the current time The The current available energy capacity of each string; Indicates the current time The The current available energy capacity of each string; For the current moment The The degree of matching between each string and the predicted total demand; For the current moment The The degree of matching between each string and the predicted total demand; For the current moment The The degree of matching between each string and the predicted total demand; () represents an exponential function; min() is the minimum value function; max() is the maximum value function; cos() is the cosine function.
4. The hierarchical coordinated control method for string energy storage according to claim 3, characterized in that, Current moment The The degree of matching between each string and the predicted total demand for: in, For the prediction period Absolute value of total internal energy demand , For the prediction period.
5. The hierarchical coordinated control method for string energy storage according to claim 1, characterized in that, The optimization problem is: in, This refers to the average power distribution of strings within an FM group. ; This represents the number of strings within the FM group; The loss coefficient function is related to SOC; The weighting coefficient for effectiveness; This is the weighting coefficient for losses; A coefficient reflecting the battery loss characteristics under different SOCs; The maximum allowable imbalance threshold; For the first Strings ; For the first The current lower limit of power for each string; For the first Current efficiency estimates for each string group; For the first The SOC value of each string; For the first The current power of each string; This represents the q-th frequency modulation group.
6. The hierarchical coordinated control method for string energy storage according to claim 1, characterized in that, The process of controlling the output frequency of the corresponding string within the frequency modulation group based on the optimal allocation instruction of each string in the frequency modulation group is as follows: The instantaneous correction amount for determining the optimal allocation instruction for each string in the frequency modulation group; The final execution instruction for each string in the frequency modulation group is calculated based on the optimal allocation instruction for each string in the frequency modulation group and the real-time correction amount of the optimal allocation instruction for each string in the frequency modulation group. The power electronic converter of the corresponding string is controlled according to the final execution command of each string in the frequency modulation group to adjust the output power of the string.
7. The hierarchical coordinated control method for string energy storage according to claim 6, characterized in that, FM group Instantaneous correction of the optimal allocation instruction for each string. for: in, Table t, time 1 The difference between the optimal allocation instruction for each string and the power measurement. ; For the first The set of neighbors of each string; The length of the sliding integral window; This is the integral gain coefficient; It is a time constant; For the current moment The The string and the first The dynamic coordination degree of each group string; The first time at time t Power measurements of each string; The first time at time t Power measurements of each string; For the first The optimal allocation instruction for each string.
8. A hierarchical collaborative control system for string energy storage, characterized in that, include: The acquisition module is used to obtain the current time. The frequency deviation time series of the power grid point of common coupling, based on the current time. Predicting the frequency deviation time series of the power grid point of common coupling for the entire station string in Cumulative frequency modulation energy reference at any time ,in, Indicates a time period; The clustering module is used to cluster based on the whole-site group string. Cumulative frequency modulation energy reference at any time Determine the current time Dynamic frequency modulation coordination matrix Based on the current time Dynamic frequency modulation coordination matrix The spectral clustering algorithm was used to cluster the entire station's strings to obtain several frequency modulation groups; The optimization module is used to obtain the real-time status of all strings within the frequency modulation group, and based on the real-time status of all strings within the frequency modulation group, calculates the total power command of the frequency modulation group issued by the power grid AGC system. As an equality constraint, with the goal of maximizing the overall efficiency of the frequency modulation group, an optimization problem is constructed, and the optimization problem is solved to obtain the optimal allocation instructions for each string in the frequency modulation group; The control module is used to control the output frequency of the corresponding string in the frequency modulation group based on the optimal allocation instruction of each string in the frequency modulation group.
9. 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, it implements the steps of the string energy storage hierarchical collaborative control method as described in any one of claims 1-7.
10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the string energy storage hierarchical collaborative control method as described in any one of claims 1-7.