A high-voltage cascade network type energy storage grading grid connection control method and system

Abstract

The application relates to a high-voltage cascade network type energy storage grading grid-connected control method and system, belonging to the field of energy storage control and power system optimization. The method realizes flexible expansion and efficient integration of the system by connecting multiple energy storage units in a cascade manner, and is suitable for different scales of power demand. On this basis, a hierarchical control strategy is proposed, which adopts two-level control methods of local control and global coordination. The local control optimizes and manages each energy storage unit in real time to ensure efficient operation; the global coordination dynamically adjusts based on the overall grid state to optimize the overall output of the energy storage system and realize consistent grid-connected control. Through hierarchical control and dynamic adjustment, the method realizes the optimized operation of the energy storage system and enhances the reliability and stability of the power system.

Description

Technical Field

[0001] This invention relates to a graded grid-connected control method for high-voltage cascaded grid-type energy storage, belonging to the field of energy storage system optimization operation. Background Technology

[0002] As the proportion of renewable energy in power systems gradually increases, the inherent randomness and uncertainty of renewable energy can adversely affect the safe operation of power systems. Equipping power systems with energy storage to support large-scale renewable energy grid integration is an effective solution. With the rapid development of energy storage technology, many control strategies based on different concepts have emerged. For different scales of power demand, flexible system expansion can be achieved through cascading energy storage units. Dynamically optimizing the operation of energy storage systems based on both the system level and the storage units is of great significance.

[0003] Energy storage systems have wide applications in improving their flexibility, efficiency, and reliability, as well as promoting the large-scale application of renewable energy. With the rapid development of energy storage systems in power grids, achieving flexible, efficient, and dynamic operation of energy storage systems based on their own structure and external demands has become a key research direction in the field of energy storage system control. Current control methods for energy storage systems exhibit poor flexibility and dynamic performance. These methods do not effectively integrate the energy storage system's own structure with the matching of the number of energy storage units to external power demand, failing to optimize the control of the energy storage system while rapidly and dynamically responding to grid demands.

[0004] Currently, there are two issues that require further research: ① To achieve flexible and efficient control of energy storage systems by cascading multiple energy storage unit modules based on varying power demand scales within the power grid. ② To improve existing control methods and establish a hierarchical control method based on local control and global coordination. This method will optimize the management of energy storage units through local control and achieve dynamic adjustment of the energy storage system through global coordination. Summary of the Invention

[0005] The purpose of this invention is to solve the above problems by proposing a hierarchical grid-connected control method for high-voltage cascaded grid-type energy storage. This invention employs a cascaded approach for multiple energy storage units to achieve flexible system expansion and efficient integration, and combines a two-layer control method based on local and global control to coordinate the optimized operation of the energy storage system. This enables more flexible and efficient optimized control of the energy storage system, providing a theoretical basis and practical method for grid-connected control of multi-high-voltage cascaded grid-type energy storage.

[0006] In a first aspect, the present invention provides a method for graded grid-connected control of high-voltage cascaded grid-type energy storage, comprising:

[0007] S1 connects multiple energy storage units in a cascade manner to form an energy storage system;

[0008] S2 identifies and analyzes the energy storage system requirements of power networks of different sizes;

[0009] S3 adjusts the output power of each energy storage unit according to the power grid's demand on the energy storage system;

[0010] S4, check if the current energy storage unit output has achieved local optimization; if not optimized, return to step S3 and continue adjusting the output; if optimized, proceed to the next step.

[0011] S5 controls the energy storage unit to achieve optimal local output;

[0012] S6 dynamically adjusts the output of the energy storage system according to the overall demand of the power grid;

[0013] S7, check if the output of the energy storage system meets the grid's needs; if not, return to step S6 and continue adjusting; if it meets the needs, proceed to the next step.

[0014] S8 ultimately obtains the overall output power of the energy storage system and performs coordinated grid-connected control.

[0015] As a further improvement of the present invention, the connection of multiple energy storage units in a cascade manner to form an energy storage system is achieved by using a high-voltage cascade modular approach to connect multiple energy storage units in a cascade manner.

[0016] As a further improvement of the present invention, the method of connecting multiple energy storage units in a cascade manner to form an energy storage system is based on the output quantity model of high-voltage cascaded energy storage modules to determine the number of cascades.

[0017] As a further improvement of the present invention, the method for establishing the output quantity model of the high-voltage cascaded energy storage module includes:

[0018] Establish a maximum output constraint model for high-voltage cascaded energy storage modules, including the maximum available output of the energy storage modules when charging demand is met and the maximum available output of the energy storage units when discharging demand is met;

[0019] The maximum available output of the energy storage module when charging is required is:

[0020]

[0021] In the formula, S OC，i For the first i The current state of charge of each energy storage unit; E i For the first i The maximum capacity of each energy storage unit; Δk This refers to charging time;

[0022] The maximum available output of the energy storage unit when discharge demand is met is:

[0023]

[0024] Based on the maximum output constraint model of high-voltage cascaded energy storage modules, a model for the number of cascaded high-voltage cascaded energy storage modules is established, specifically including:

[0025] The number of cascaded energy storage units should meet the following requirements when charging demand is present:

[0026]

[0027] in, N This refers to the number of cascaded energy storage modules. P re For electricity demand from the outside world;

[0028] The number of cascaded energy storage units should meet the following requirements during discharge:

[0029]

[0030] in, i For the first i One energy storage unit.

[0031] As a further improvement of the present invention, the step of adjusting the output power of each energy storage unit according to the power network's demand on the energy storage system is a battery module output model within the energy storage unit.

[0032] As a further improvement of the present invention, the method for establishing the output model of the battery module in the energy storage unit includes:

[0033] Establish a power output constraint model for the battery module in the energy storage module, including:

[0034] Maximum available output of the battery module during charging demand:

[0035]

[0036] In the formula, S OC，ij For the first i The first energy storage unit j The current state of charge of each battery module; E ij For the first i The first energy storage unit j Maximum capacity of each battery module; Δ k This refers to charging time;

[0037] Maximum available output of the energy storage unit when discharge demand is met:

[0038]

[0039] Output constraints based on the inherent limits of the energy storage module:

[0040]

[0041] In the formula, P ij,max For the first i The first energy storage module j Maximum available power of each battery module;

[0042] Battery module output constraints based on energy storage module output:

[0043]

[0044] In the formula, M This refers to the number of battery modules in the energy storage module.

[0045] Establish a target function model for the output of energy storage modules in an energy storage system, including:

[0046] The state-of-charge model of the battery module after output is as follows:

[0047]

[0048] In the formula, S OC,i ( k )for k Time of the first i The first energy storage module j The state of charge of each battery module; P i ( k )for k Time of the first i The first energy storage module j The output power of each battery module E This refers to the rated capacity of the energy storage battery module.

[0049] Mathematical model of the maximum and minimum state of charge of the battery module after output:

[0050]

[0051] In the formula, S OC,i1 ( k+ 1), S OC,i2 ( k+ 1),..., S OC,ij ( k+ 1) respectively the first iThe first and second energy storage modules are... j Each battery module k SOC at time +1;

[0052]

[0053] In the formula, S OC_i,max ( k +1) is k +1 moment i The maximum SOC of the battery module in each energy storage module S OC_i,min ( k +1) is k +1 moment i Minimum SOC of battery module in energy storage modules.

[0054] As a further improvement of the present invention, the step of dynamically adjusting the output of the energy storage system according to the overall needs of the power grid is to dynamically adjust the overall output model of the energy storage system.

[0055] As a further improvement of the present invention, the method for establishing the overall output model of the energy storage system includes:

[0056] Establish a constraint model for the output of energy storage modules in the energy storage system:

[0057] Output constraints based on the energy storage module's own limits:

[0058]

[0059] In the formula, P i,max This represents the maximum available power of the energy storage module.

[0060] Energy storage module output constraints based on grid demand:

[0061]

[0062] Establish the objective function model for the output of the energy storage module in the energy storage system:

[0063] The state-of-charge model of the energy storage unit after output is as follows:

[0064]

[0065] In the formula, S OC,i ( k )for k Time of the first i The state of charge of each energy storage module P i ( k )fork Time of the first i The output power of each energy storage module E 0 represents the rated capacity of the energy storage unit;

[0066] Mathematical model of the maximum and minimum state of charge of the energy storage unit after it outputs power:

[0067]

[0068] In the formula, S OC,1 ( k+ 1), S OC,2 ( k+ 1),..., S OC,i ( k+ 1) These are the 1st, 2nd and... i Each energy storage module is in k SOC at time +1;

[0069]

[0070] In the formula, S OC,max ( k +1) is k The maximum SOC value of the energy storage module at time +1 S OC,max ( k +1) is k The minimum SOC value in the energy storage module at time +1.

[0071] Secondly, the present invention provides a high-voltage cascaded grid-type energy storage hierarchical grid-connected control system, comprising:

[0072] Cascading modules are used to connect multiple energy storage units in a cascading manner to form an energy storage system;

[0073] The local control module is used to identify and analyze the demand of power networks of different sizes for energy storage systems; adjust the output power of each energy storage unit according to the demand of the power network for energy storage systems; check whether the current output of the energy storage unit has achieved local optimization; if not optimized, return to continue adjusting the output; control the energy storage units to achieve local optimal output.

[0074] The global coordination module is used to: dynamically adjust the output of the energy storage system according to the overall demand of the power grid; check whether the output of the energy storage system meets the demand of the power grid; if not, continue to adjust; and finally coordinate and unify grid connection control.

[0075] Thirdly, the present invention provides an electronic 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 high-voltage cascaded grid-type energy storage hierarchical grid connection control method.

[0076] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the high-voltage cascaded grid-type energy storage hierarchical grid-connected control method.

[0077] Fifthly, the present invention provides a computer program product, the computer program product including computer instructions, the computer instructions instructing a computer to execute the high-voltage cascaded grid-type energy storage graded grid connection control method.

[0078] The advantages of this invention over the prior art are as follows:

[0079] Compared with the prior art, the beneficial effects of the present invention are as follows: taking into account the external power demand and the structure of the energy storage system itself, the output of the energy storage units is reasonably allocated by cascading the energy storage units. Based on the hierarchical concept, the control of the energy storage system is divided into local control and global control. The energy storage units are optimized and managed by local control, and the overall output of the energy storage system is optimized by global control, thus providing a method for the flexible, efficient and dynamic operation of the energy storage system.

[0080] This invention employs a high-voltage cascaded modular design, connecting multiple energy storage units in a cascaded manner to achieve flexible system expansion and efficient integration, suitable for power demands of varying scales. It utilizes two hierarchical control methods: local control and global coordination. Local control performs real-time optimization management for each energy storage unit, ensuring its efficient operation; global coordination dynamically adjusts based on the overall grid status, optimizing the overall output of the energy storage system and achieving coordinated grid-connected control. This method, through hierarchical control and dynamic adjustment, achieves optimized operation of the energy storage system, enhancing the reliability and stability of the power system. Attached image description:

[0081] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following description is provided with accompanying drawings of the relevant technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0082] Figure 1 This is a flowchart of the graded grid connection control method for high-voltage cascaded grid-type energy storage;

[0083] Figure 2 This is a framework diagram of the cascaded and hierarchical control of energy storage unit modules. Detailed implementation method:

[0084] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0085] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0086] The purpose of this invention is to solve the above problems. The first objective of this invention is to provide a method for graded grid-connected control of high-voltage cascaded grid-type energy storage, comprising the following steps:

[0087] S1 connects multiple energy storage units in a cascade manner to form an energy storage system;

[0088] S2 identifies and analyzes the energy storage system requirements of power networks of different sizes;

[0089] S3 adjusts the output power of each energy storage unit according to the power grid's demand on the energy storage system;

[0090] S4, check if the current energy storage unit output has achieved local optimization; if not optimized, return to step S3 and continue adjusting the output; if optimized, proceed to the next step.

[0091] S5 controls the energy storage unit to achieve optimal local output;

[0092] S6 dynamically adjusts the output of the energy storage system according to the overall demand of the power grid;

[0093] S7, check if the output of the energy storage system meets the grid's needs; if not, return to step S6 and continue adjusting; if it meets the needs, proceed to the next step.

[0094] S8 ultimately obtains the overall output power of the energy storage system and performs coordinated grid-connected control.

[0095] As an example, the control method for high-voltage cascaded grid-type energy storage has certain complexities, mainly manifested in: achieving flexible expansion and efficient integration of the energy storage system based on the power demand of different scales in the power network; and, starting from improving the reliability and stability of the energy storage system, implementing hierarchical control of the energy storage system based on the grid status, dynamically adjusting the energy storage system, and optimizing the operation mode of the energy storage system. This invention solves the problem of insufficient dynamic performance in traditional energy storage system control methods, enhancing the flexibility and efficiency of the energy storage system.

[0096] Furthermore, the method of this invention is a multi-type energy storage application value assessment method based on market analysis. The basic idea is to cascade multiple energy storage units using a high-voltage cascaded modular approach to address different scales of power demand in the power grid. To address the insufficient dynamic performance of traditional energy storage system control methods, this invention proposes an optimized management approach for energy storage units based on local control, and a dynamically adjusted approach for the energy storage system based on the grid status in a globally coordinated manner, providing a control method for efficient and dynamic control of energy storage systems.

[0097] Furthermore, the technical solution provided by this invention is to control the operation of the energy storage system based on a modular cascading and hierarchical control method, ensuring that the control method enables the flexible, efficient, and dynamic operation of the energy storage system. By connecting multiple energy storage units in a cascaded manner, flexible expansion and efficient integration of the system are achieved, making it suitable for power demands of different scales. Based on this, a hierarchical control strategy is proposed, employing two levels of control methods: local control and global coordination. Local control performs real-time optimization management for each energy storage unit to ensure its efficient operation; global coordination dynamically adjusts based on the overall grid status, optimizing the overall output of the energy storage system and achieving coordinated grid-connected control. This method, through hierarchical control and dynamic adjustment, achieves optimized operation of the energy storage system, enhancing the reliability and stability of the power system.

[0098] The energy storage system adopts a high-voltage cascaded modular design. Taking into account the power demand of different scales in the power system, multiple energy storage units are connected in a cascaded manner to meet the processing requirements, which increases the scalability and flexibility of the energy storage system.

[0099] Based on the concept of hierarchical control, a hierarchical control strategy for grid-based energy storage is proposed. By employing two levels of control methods—local control and global coordination—based on electricity demand and the energy storage system's own state, efficient and dynamic operation of the energy storage system is achieved, enhancing the reliability and stability of the power system.

[0100] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0101] based on Figure 1 The specific steps of this embodiment are as follows:

[0102] Start: S1, Cascading of multiple energy storage units: Connecting multiple energy storage units in a cascading manner to form an energy storage system.

[0103] S2, Demand for different sizes of power networks: Identify and analyze the demand for energy storage systems for power networks of different sizes.

[0104] S3, Adjust the output of each energy storage unit: Adjust the output power of each energy storage unit according to the needs of the power network.

[0105] S4, Is local optimization achieved? Check whether the current energy storage unit output has achieved local optimization.

[0106] No: If not optimized, return to the "Adjust the output of each energy storage unit" step and continue to adjust the output.

[0107] Yes: If optimized, proceed to the next step.

[0108] S5 enables local optimization control: the energy storage unit is controlled to achieve optimal local output.

[0109] S6, based on the overall demand of the power grid: considers the demand of the entire power grid, not just the local demand.

[0110] Dynamically adjust the output of the energy storage system: dynamically adjust the output of the energy storage system according to the overall demand of the power grid.

[0111] S7, does it meet grid demand? Check if the output of the energy storage system meets the grid demand.

[0112] No: If not, return to the "Dynamically Adjust Energy Storage System Output" step and continue adjusting.

[0113] Yes: If satisfied, proceed to the next step.

[0114] S8, obtain the overall output of the energy storage system: determine the overall output power of the energy storage system to meet the grid demand.

[0115] Conclusion: The energy storage system has been optimized to meet grid demand and is delivering the required power.

[0116] like Figure 2 As shown, this involves cascading multiple energy storage units and optimizing and adjusting them according to different grid demands. Through local and overall optimization, the energy storage system effectively meets the dynamic needs of the grid.

[0117] In this method, multiple energy storage units are connected in a cascade manner, and the output quantity model of high-voltage cascaded energy storage modules is used for confirmation. The method for establishing the output quantity model of high-voltage cascaded energy storage modules is as follows:

[0118] Establish a power output model for high-voltage cascaded energy storage modules;

[0119] (1) Establish a maximum output constraint model for high-voltage cascaded energy storage modules.

[0120] Maximum available output of the energy storage module when charging is required:

[0121] (1)

[0122] In the formula, S OC，i For the first i The current state of charge of each energy storage unit; E i For the first i The maximum capacity of each energy storage unit; Δ k This refers to the charging time.

[0123] Maximum available output of the energy storage unit when discharge demand is met:

[0124] (2)

[0125] (2) Establish a model for the number of high-voltage cascaded energy storage modules.

[0126] The number of cascaded energy storage units should meet the following requirements when charging demand is present:

[0127] (3)

[0128] in, N This refers to the number of cascaded energy storage modules. P re This is to meet the electricity demand from the outside world.

[0129] The number of cascaded energy storage units should meet the following requirements during discharge:

[0130] (4)

[0131] The dynamic adjustment of the energy storage system's output based on the overall demand of the power grid involves dynamically adjusting the overall output model of the energy storage system. The method for establishing the overall output model of the energy storage system includes:

[0132] Establish an overall output model for the energy storage system based on the overall power grid status.

[0133] (3) Establish the output constraint model of the energy storage module in the energy storage system:

[0134] Output constraints based on the energy storage module's own limits:

[0135] (5)

[0136] In the formula, P i,max This represents the maximum available power of the energy storage module.

[0137] Energy storage module output constraints based on grid demand:

[0138] (6)

[0139] (4) Establish the objective function model for the output of the energy storage module in the energy storage system:

[0140] The state-of-charge model of the energy storage unit after output is as follows:

[0141] (7)

[0142] In the formula, S OC,i ( k )for k Time of the first i The state of charge of each energy storage module P i ( k )for k Time of the first i The output power of each energy storage module E 0 represents the rated capacity of the energy storage unit.

[0143] Mathematical model of the maximum and minimum state of charge of the energy storage unit after it outputs power:

[0144] (8)

[0145] In the formula, S OC,1 ( k+ 1), S OC,2 ( k+ 1),..., S OC,i ( k+ 1) These are the 1st, 2nd and... i Each energy storage module is in k SOC at time +1.

[0146] (9)

[0147] In the formula, S OC,max ( k +1) is k The maximum SOC value of the energy storage module at time +1 S OC,max ( k +1) is kThe minimum SOC value in the energy storage module at time +1.

[0148] The adjustment of the output power of each energy storage unit according to the power grid's demand on the energy storage system constitutes the battery module output model within the energy storage unit. The method for establishing the battery module output model within the energy storage unit includes:

[0149] Based on the output of each energy storage unit, establish a power output model for the battery module within the energy storage unit:

[0150] (5) Establish a power output constraint model for the battery module in the energy storage module:

[0151] Maximum available output of the battery module during charging demand:

[0152] (10)

[0153] In the formula, S OC，ij For the first i The first energy storage unit j The current state of charge of each battery module; E ij For the first i The first energy storage unit j Maximum capacity of each battery module; Δ k This refers to the charging time.

[0154] Maximum available output of the energy storage unit when discharge demand is met:

[0155] (11)

[0156] Output constraints based on the inherent limits of the energy storage module:

[0157] (12)

[0158] In the formula, P ij,max For the first i The first energy storage module j Maximum available power of each battery module.

[0159] Battery module output constraints based on energy storage module output:

[0160] (13)

[0161] In the formula, M This represents the number of battery modules in the energy storage module.

[0162] (6) Establish the objective function model for the output of the energy storage module in the energy storage system:

[0163] The state-of-charge model of the battery module after output is as follows:

[0164] (14)

[0165] In the formula, S OC,i ( k )for k Time of the first i The first energy storage module j The state of charge of each battery module; P i ( k )for k Time of the first i The first energy storage module j The output power of each battery module E This refers to the rated capacity of the energy storage battery module.

[0166] Mathematical model of the maximum and minimum state of charge of the battery module after output:

[0167] (15)

[0168] In the formula, S OC,i1 ( k+ 1), S OC,i2 ( k+ 1),..., S OC,ij ( k+ 1) respectively the first i The first and second energy storage modules are... j Each battery module k SOC at time +1.

[0169] (16)

[0170] In the formula, S OC_i,max ( k +1) is k +1 moment i The maximum SOC of the battery module in each energy storage module S OC_i,min ( k +1) is k +1 moment i Minimum SOC of battery module in energy storage modules.

[0171] The second objective of this invention is to provide a high-voltage cascaded grid-type energy storage hierarchical grid-connected control system, comprising:

[0172] Cascading modules are used to connect multiple energy storage units in a cascading manner to form an energy storage system;

[0173] The local control module is used to identify and analyze the demand of power networks of different sizes for energy storage systems; adjust the output power of each energy storage unit according to the demand of the power network for energy storage systems; check whether the current output of the energy storage unit has achieved local optimization; if not optimized, return to continue adjusting the output; control the energy storage units to achieve local optimal output.

[0174] The global coordination module is used to: dynamically adjust the output of the energy storage system according to the overall demand of the power grid; check whether the output of the energy storage system meets the demand of the power grid; if not, continue to adjust; and finally coordinate and unify grid connection control.

[0175] A third objective of this invention is to provide an electronic device, including 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 high-voltage cascaded grid-type energy storage hierarchical grid-connected control method. The device also includes a communication interface and a bus.

[0176] A fourth objective of this invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the high-voltage cascaded grid-type energy storage hierarchical grid-connected control method.

[0177] A fifth objective of this invention is to provide a computer program product comprising computer instructions that instruct a computer to execute the high-voltage cascaded grid-type energy storage graded grid connection control method.

[0178] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0179] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0180] This invention may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, readable storage media, optical storage, etc.) containing computer-usable program code.

[0181] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0182] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for graded grid-connected control of high-voltage cascaded grid-type energy storage, characterized in that, include: S1 connects multiple energy storage units in a cascade manner to form an energy storage system; S2 identifies and analyzes the energy storage system requirements of power networks of different sizes; S3 adjusts the output power of each energy storage unit according to the power grid's demand on the energy storage system; S4, check if the current energy storage unit output has achieved local optimization; if not optimized, return to step S3 and continue adjusting the output; if optimized, proceed to the next step. S5 controls the energy storage unit to achieve optimal local output; S6 dynamically adjusts the output of the energy storage system according to the overall demand of the power grid; S7, check if the output of the energy storage system meets the grid's needs; if not, return to step S6 and continue adjusting; if it meets the needs, proceed to the next step. S8 ultimately obtains the overall output power of the energy storage system and performs coordinated grid-connected control. The method of connecting multiple energy storage units in a cascade manner to form an energy storage system is based on the output quantity model of high-voltage cascaded energy storage modules to determine the number of cascades. The method for establishing the output quantity model of the high-voltage cascaded energy storage module includes: Establish a maximum output constraint model for high-voltage cascaded energy storage modules, including the maximum available output of the energy storage modules when charging demand is met and the maximum available output of the energy storage units when discharging demand is met; The maximum available output of the energy storage module when charging is required is: In the formula, S OC，i For the first i The current state of charge of each energy storage unit; E i For the first i The maximum capacity of each energy storage unit; Δ k This refers to charging time; The maximum available output of the energy storage unit when discharge demand is met is: Based on the maximum output constraint model of high-voltage cascaded energy storage modules, a model for the number of cascaded high-voltage cascaded energy storage modules is established, specifically including: The number of cascaded energy storage units should meet the following requirements when charging demand is present: in, N This refers to the number of cascaded energy storage modules. P re For electricity demand from the outside world; The number of cascaded energy storage units should meet the following requirements during discharge: in, i For the first i One energy storage unit.

2. The high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to claim 1, characterized in that, The method of connecting multiple energy storage units in a cascade manner to form an energy storage system is to use a high-voltage cascade modular approach to connect multiple energy storage units in a cascade manner.

3. The method for graded grid connection control of high-voltage cascaded grid-type energy storage according to claim 1, characterized in that, The method of adjusting the output power of each energy storage unit according to the power grid's demand on the energy storage system is the battery module output model within the energy storage unit.

4. The high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to claim 3, characterized in that, The method for establishing the battery module output model within the energy storage unit includes: Establish a power output constraint model for the battery module in the energy storage module, including: Maximum available output of the battery module during charging demand: In the formula, S OC，ij For the first i The first energy storage unit j The current state of charge of each battery module; E ij For the first i The first energy storage unit j Maximum capacity of each battery module; Δ k This refers to charging time; Maximum available output of the energy storage unit when discharge demand is met: Output constraints based on the inherent limits of the energy storage module: In the formula, P ij,max For the first i The first energy storage module j Maximum available power of each battery module; Battery module output constraints based on energy storage module output: In the formula, M This refers to the number of battery modules in the energy storage module. Establish a target function model for the output of energy storage modules in an energy storage system, including: The state-of-charge model of the battery module after output is as follows: In the formula, S OC,ij ( k )for k Time of the first i The first energy storage module j The state of charge of each battery module; P ij ( k )for k Time of the first i The first energy storage module j The output power of each battery module E This refers to the rated capacity of the energy storage battery module. Mathematical model of the maximum and minimum state of charge of the battery module after output: In the formula, S OC,i1 ( k+ 1), S OC,i2 ( k+ 1),..., S OC,ij ( k+ 1) respectively the first i The first and second energy storage modules are... j Each battery module k SOC at time +1; In the formula, S OC_i,max ( k +1) is k +1 moment i The maximum SOC of the battery module in each energy storage module S OC_i,min ( k +1) is k +1 moment i Minimum SOC of battery module in each energy storage module.

5. The high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to claim 1, characterized in that, The aforementioned dynamic adjustment of the energy storage system's output based on the overall demand of the power grid refers to the dynamic adjustment of the overall output model of the energy storage system.

6. The high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to claim 5, characterized in that, The method for establishing the overall output model of the energy storage system includes: Establish a constraint model for the output of energy storage modules in the energy storage system: Output constraints based on the inherent limits of the energy storage module: In the formula, P i,max This represents the maximum available power of the energy storage module. Energy storage module output constraints based on grid demand: Establish the objective function model for the output of the energy storage module in the energy storage system: The state-of-charge model of the energy storage unit after output is as follows: In the formula, S OC,i ( k )for k Time of the first i The state of charge of each energy storage module P i ( k )for k Time of the first i The output power of each energy storage module E 0 represents the rated capacity of the energy storage unit; Mathematical model of the maximum and minimum state of charge of the energy storage unit after it outputs power: In the formula, S OC,1 ( k+ 1), S OC,2 ( k+ 1),..., S OC,i ( k+ 1) These are the 1st, 2nd and... i Each energy storage module is in k SOC at time +1; In the formula, S OC,max ( k +1) is k The maximum SOC value of the energy storage module at time +1 S OC,max ( k +1) is k The minimum SOC value in the energy storage module at time +1.

7. A high-voltage cascaded grid-type energy storage hierarchical grid-connected control system, implementing the high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to any one of claims 1-6; characterized in that, include: Cascading modules are used to connect multiple energy storage units in a cascading manner to form an energy storage system; The local control module is used to identify and analyze the demand of power networks of different sizes for energy storage systems; adjust the output power of each energy storage unit according to the demand of the power network for energy storage systems; check whether the current output of the energy storage unit has achieved local optimization; if not optimized, return to continue adjusting the output; control the energy storage units to achieve local optimal output. The global coordination module is used to: dynamically adjust the output of the energy storage system according to the overall demand of the power grid; check whether the output of the energy storage system meets the demand of the power grid; if not, continue to adjust; and finally coordinate and unify grid connection control.

8. An electronic device, characterized in that, It includes 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 high-voltage cascaded grid-type energy storage graded grid-connected control method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the high-voltage cascaded grid-type energy storage hierarchical grid-connected control method according to any one of claims 1-6.

10. A computer program product, the computer program product comprising computer instructions, characterized in that, The computer instructions instruct the computer to execute the high-voltage cascaded grid-type energy storage graded grid connection control method according to any one of claims 1-6.

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