Energy storage system control method and related device

Abstract

The invention discloses an energy storage system control method and a related device, relates to the technical field of energy storage, and aims at responding to a power dispatching instruction and controlling the energy storage system in the case that the charge states of battery packs in the energy storage system are different. By comprehensively analyzing a power scheduling requirement corresponding to the power scheduling instruction and the charge state and rated power of each battery pack, determining a schedulable battery pack in each battery pack and determining the scheduling power of the schedulable battery pack; the charge state and the total rated power of the dispatchable battery pack meet the power dispatching requirement corresponding to the power dispatching instruction, so that a control instruction carrying dispatching power is sent to an energy storage converter connected with the dispatchable battery pack; the situation that the non-dispatchable battery pack reaches the upper limit value or the lower limit value too early due to power dispatching of the non-dispatchable battery pack is avoided, power optimal distribution and dynamic balance of the state of charge of the battery pack are achieved, and the total dispatchable battery capacity is improved.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an energy storage system control method and related devices. Background Technology

[0002] New energy sources, such as photovoltaic power generation, are greatly affected by various factors, resulting in intermittent, highly volatile, and random power output, which poses a series of challenges to grid dispatch and protection. Therefore, new energy power plants are generally equipped with energy storage systems of a certain capacity. By rationally controlling the charging and discharging of the battery packs in the energy storage system, the power dispatch requirements of the new energy power plant can be met, reducing the impact of power fluctuations from the new energy power plant on the grid.

[0003] Currently, energy storage systems use an average power distribution method after receiving power dispatch instructions, but the dispatch effect is not ideal. Summary of the Invention

[0004] In view of the above problems, this application provides an energy storage system control method and related apparatus to achieve optimized power allocation and dynamic balancing of battery pack state of charge, thereby improving the total dispatchable battery capacity. The specific solution is as follows:

[0005] The first aspect of this application provides a control method for an energy storage system, comprising:

[0006] In response to a power dispatch command, when there are differences in the state of charge of each battery pack in the energy storage system, the dispatchable battery packs in the energy storage system and the dispatchable power of the dispatchable battery packs are determined, and the state of charge and total rated power of the dispatchable battery packs meet the power dispatch requirements corresponding to the power dispatch command.

[0007] Send a control command carrying the scheduled power to the energy storage converter connected to the schedulable battery pack.

[0008] In one possible implementation, determining the schedulable battery pack in the energy storage system and the schedulable power of the schedulable battery pack includes:

[0009] Based on the type of the power scheduling command and the state of charge of each battery pack, a target battery pack whose state of charge meets the power scheduling requirements is determined in each battery pack. The types of the power scheduling command include discharge command and charging command.

[0010] Based on the total dispatch power of the power dispatch command and the rated power of each target battery pack, determine the dispatchable battery packs among the target battery packs whose total rated power meets the power dispatch requirements, and determine the dispatch power of the dispatchable battery packs.

[0011] In one possible implementation, determining the target battery pack whose state of charge (SBC) satisfies the power scheduling requirement, based on the type of the power scheduling instruction and the SBC of each battery pack, includes:

[0012] If the type of the scheduling instruction is a discharge instruction, the battery pack whose state of charge is not less than the preset state of charge lower limit is determined as the target battery pack;

[0013] If the type of the scheduling instruction is a charging instruction, the battery pack whose state of charge is not greater than the preset upper limit of the state of charge is determined as the target battery pack.

[0014] In one possible implementation, determining the target battery pack whose state of charge (SBC) satisfies the power scheduling requirement, based on the type of the power scheduling instruction and the SBC of each battery pack, includes:

[0015] The state of each battery pack is determined according to its state of charge, and the states of the battery packs include: a first state, a second state, and a third state; the battery pack in the first state is preferentially charged, the battery pack in the second state can be charged or discharged, and the battery pack in the third state is preferentially discharged.

[0016] If the type of the scheduling instruction is a discharge instruction, the battery pack in the second state and the battery pack in the third state are determined as the target battery pack;

[0017] If the scheduling instruction is a charging instruction, the battery pack in the second state and the battery pack in the first state are identified as the target battery pack.

[0018] In one possible implementation, determining the state of each of the battery packs based on the state of charge of each battery pack includes:

[0019] If the state of charge of the battery pack is less than a preset state of charge limit, the battery pack is determined to be in the first state.

[0020] If the state of charge of the battery pack is not less than the preset lower limit of the state of charge and not greater than the preset upper limit of the state of charge, the battery pack is determined to be in the second state;

[0021] If the state of charge of the battery pack is greater than the preset upper limit of the state of charge, the battery pack is determined to be in the third state.

[0022] In one possible implementation, determining the dispatchable battery packs whose total rated power meets the power dispatch requirements based on the total dispatch power of the power dispatch instruction and the rated power of each of the target battery packs, and determining the dispatch power of the dispatchable battery packs, includes:

[0023] Based on the type of the scheduling instruction, the scheduling priority of the target battery pack in different states is determined. The scheduling priority includes a first priority and a second priority, wherein the first priority is higher than the second priority.

[0024] If the total rated power of the target battery pack with the first scheduling priority is not less than the total scheduling power, the target battery pack with the first scheduling priority is determined as the schedulable battery pack, and the total scheduling power is proportionally allocated according to the scheduling margin of the schedulable battery pack to determine the scheduling power of the schedulable battery pack; if the type of the scheduling instruction is a discharge instruction, the scheduling margin is a discharge margin; if the type of the scheduling instruction is a charging instruction, the scheduling margin is a charging margin.

[0025] In one possible implementation, determining the dispatchable battery packs whose total rated power meets the power dispatch requirements based on the total dispatch power of the power dispatch instruction and the rated power of each of the target battery packs, and determining the dispatch power of the dispatchable battery packs, includes:

[0026] If the total rated power of the target battery pack with the first scheduling priority is less than the total scheduling power, the target battery pack is determined as the schedulable battery pack, wherein the schedulable battery pack with the first scheduling priority is the first schedulable battery pack, and the schedulable battery pack with the second scheduling priority is the second schedulable battery pack.

[0027] If the total rated power of the dispatchable battery pack is not less than the total dispatchable power, the difference between the total dispatchable power and the total rated power of the first dispatchable battery pack is determined as the remaining dispatchable power, the rated power of the first dispatchable battery pack is determined as the dispatchable power of the first dispatchable battery pack, and the remaining dispatchable power is proportionally allocated according to the dispatch margin of the second dispatchable battery pack to determine the dispatchable power of the second dispatchable battery pack.

[0028] If the total rated power of the schedulable battery pack is less than the total schedulable power, the rated power of the schedulable battery pack is determined as the schedulable power of the schedulable battery pack.

[0029] In one possible implementation, the discharge margin of the battery pack in the first state is the state of charge, and the charging margin is the difference between a preset upper limit of the state of charge and the state of charge.

[0030] The discharge margin of the battery pack in the second state is the difference between the state of charge and the preset upper limit of the state of charge, and the charging margin is the difference between the preset upper limit of the state of charge and the state of charge.

[0031] The discharge margin of the battery pack in the third state is the difference between the state of charge and the preset state of charge limit, and the charging margin is the difference between 1 and the state of charge.

[0032] A second aspect of this application provides a controller comprising at least one processor and a memory connected to the processor, wherein:

[0033] The memory is used to store computer programs;

[0034] The processor is used to execute the computer program so that the controller can implement the energy storage system control method of the first aspect or any implementation thereof.

[0035] A third aspect of this application provides an energy storage system, including a controller, a plurality of battery packs, and an energy storage converter connected to each of the battery packs respectively.

[0036] The controller is used to execute the energy storage system control method of the first aspect or any implementation thereof described above;

[0037] The energy storage converter is used to execute the control commands sent by the controller.

[0038] The fourth aspect of this application provides a computer program product including computer-readable instructions that, when executed on a controller, cause the controller to implement the energy storage system control method of the first aspect or any implementation thereof.

[0039] By utilizing the above technical solutions, this application provides an energy storage system control method and related apparatus that, in response to a power dispatch command, determines the dispatchable battery groups and their dispatch power in the energy storage system by comprehensively analyzing the power dispatch requirements corresponding to the power dispatch command, as well as the state of charge and rated power of each battery group, when there are differences in the state of charge of each battery group in the energy storage system. This ensures that the state of charge and total rated power of the dispatchable battery groups meet the power dispatch requirements corresponding to the power dispatch command. The method then sends a control command carrying the dispatch power to the energy storage converter connected to the dispatchable battery groups, avoiding premature reaching of the upper or lower limits of the undispatchable battery groups due to power dispatching, thereby achieving optimized power allocation and dynamic balance of the battery group's state of charge, and increasing the total dispatchable battery capacity. Attached Figure Description

[0040] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0041] Figure 1 A schematic diagram of an energy storage system architecture provided in this application embodiment;

[0042] Figure 2 This is a schematic diagram of the structure of a controller provided in an embodiment of this application;

[0043] Figure 3 A flowchart illustrating an energy storage system control method provided in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the battery pack state division provided in an embodiment of this application. Detailed Implementation

[0045] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0046] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0047] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0048] Currently, after receiving a power dispatch command, the energy storage system uses a power equalization method to distribute power equally among the various energy storage converters in the system, controlling each battery pack to charge and discharge at the same power. However, if there are differences in the battery packs' charge levels, some battery packs may reach their upper or lower limits prematurely, reducing the total dispatchable battery capacity.

[0049] To address the aforementioned technical problems, this application provides an energy storage system control method and related apparatus. The energy storage system control method and related apparatus of this application will be described in detail below with reference to the accompanying drawings.

[0050] Please see Figure 1 , Figure 1 A schematic diagram of an energy storage system architecture according to an embodiment of this application is shown. The energy storage system includes a controller, multiple battery packs, and an energy storage converter connected to each battery pack. Figure 1 (Using an example comprising n battery packs and n energy storage converters, the outputs of each energy storage converter are connected in parallel, the input of each energy storage converter is connected to an independent battery pack, and the other end of each energy storage converter is connected in parallel to a transformer, which is then connected to the power grid.)

[0051] In addition, each energy storage converter is connected to the controller and receives control commands from the controller.

[0052] In some embodiments, the energy storage system can be installed in a new energy power station, which can be a photovoltaic power station, a wind power station, a hydropower station, etc.

[0053] The controller can respond to power dispatch commands from the power grid or local renewable energy power plants. These commands specify the charging and discharging requirements for the energy storage system. Power dispatch commands include both discharging and charging commands, and include the total dispatched power. The controller can also acquire the state of charge (SOC) of each battery pack. Given differences in SOC among the battery packs, the controller comprehensively analyzes the power dispatch requirements corresponding to the commands, as well as the SOC and rated power of each battery pack. It then determines the dispatchable battery packs and their dispatchable power, and sends control commands carrying the dispatched power to the energy storage converter connected to the dispatchable battery packs. This causes the energy storage converter to execute the control commands, controlling the charging or discharging of the dispatchable battery packs.

[0054] The following description Figure 1 Product form of the controller;

[0055] Figure 2 A schematic diagram of a controller is provided, such as... Figure 2 As shown, the controller includes a bus 201, a processor 202, a communication interface 203, and a memory 204. The processor 202, the memory 204, and the communication interface 203 communicate with each other via the bus 201.

[0056] Bus 201 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 3 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0057] The processor 202 can be any one or more of the following processors: central processing unit (CPU), graphics processing unit (GPU), microprocessor (MP), or digital signal processor (DSP).

[0058] Memory 204 may include volatile memory, such as random access memory (RAM). Memory 204 may also include non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid state drive (SSD).

[0059] The memory 204 can be used to store software code related to the energy storage system control method, and the processor 202 can execute the steps of the chip's energy storage system control method, and can also schedule other units to achieve corresponding functions.

[0060] It should be understood that the controller can be a centralized or distributed device, and the processor 202 in the controller can be a hardware circuit (such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a general-purpose processor, a digital signal processor (DSP), a microprocessor or a microcontroller, etc.) or a combination of these hardware circuits. For example, the processor can be a hardware system with instruction execution capabilities, such as a CPU or a DSP, or a hardware system without instruction execution capabilities, such as an ASIC or an FPGA, or a combination of the aforementioned hardware systems without instruction execution capabilities and hardware systems with instruction execution capabilities.

[0061] This application provides a control method for an energy storage system. The control method for the energy storage system according to this application will be described in detail below with reference to the accompanying drawings.

[0062] This embodiment provides a control method for an energy storage system. In response to a power dispatch command, when there are differences in the state of charge of each battery pack in the energy storage system, the method first determines the dispatchable battery packs and their dispatch power in the energy storage system, and then sends a control command carrying the dispatch power to the energy storage converter connected to the dispatchable battery packs in the energy storage system.

[0063] For example, power dispatch instructions are sent locally by the power grid or new energy power plants based on power dispatch needs.

[0064] By parsing the power dispatch instructions, the power dispatch requirements can be obtained, such as determining whether the current power dispatch is for charging or discharging, and the total dispatch power for this operation.

[0065] The state of charge (SOC) and total rated power of the dispatchable battery pack meet the power dispatch requirements corresponding to the power dispatch command. Taking the power dispatch command as a discharge command as an example, the SOC of the dispatchable battery pack is at least not less than the preset lower limit of the SOC and the total rated power of the dispatchable battery pack meets the power dispatch requirements. Taking the power dispatch command as a charging command as an example, the SOC of the dispatchable battery pack is at least not greater than the preset upper limit of the SOC and the total rated power of the dispatchable battery pack meets the power dispatch requirements.

[0066] In other words, when the state of charge (SOC) of the various battery packs in the energy storage system differs, this embodiment does not control each battery pack to charge and discharge at the same power. Instead, it controls the charging and discharging of the schedulable battery packs. When responding to a discharge command, it avoids controlling the battery packs with lower SOC to discharge, thus preventing them from reaching the preset SOC limit prematurely, which would cause all battery packs to stop discharging and reduce the total dischargeable battery capacity. Similarly, when responding to a charging command, it avoids controlling the battery packs with higher SOC to charge, thus preventing them from reaching the preset SOC limit prematurely, which would cause all battery packs to stop charging and reduce the total rechargeable battery capacity.

[0067] Reference Figure 3 , Figure 3 This is a flowchart illustrating an energy storage system control method provided in an embodiment of this application, as shown below. Figure 3 As shown in the embodiment of this application, an energy storage system control method may include steps 301 to 303, which are described in detail below.

[0068] 301: Based on the type of power dispatch instruction and the state of charge of each battery pack, determine the target battery pack whose state of charge meets the power dispatch requirements among all battery packs;

[0069] Power scheduling commands include discharge commands and charging commands.

[0070] For example, if the scheduling instruction is a discharge instruction, the battery pack with a state of charge not less than the preset lower limit of the state of charge is determined as the target battery pack; if the scheduling instruction is a charging instruction, the battery pack with a state of charge not greater than the preset upper limit of the state of charge is determined as the target battery pack.

[0071] For example, the state of each battery pack is determined based on its state of charge (SOC), and the SOC characterizes the charge / discharge capability of the battery pack. Figure 4 As shown, the battery pack states include: State I, State II, and State III.

[0072] The battery pack in the first state is charged first. In some embodiments, the battery pack in the first state can be charged but not discharged. In other embodiments, the battery pack in the first state is charged first, and can also be discharged in extreme scenarios.

[0073] The battery pack in its second state can be charged and discharged.

[0074] The battery pack in the third state is preferentially discharged. In some embodiments, the battery pack in the third state can be discharged but not charged. In other embodiments, the battery pack in the third state is preferentially discharged, but can also be charged in extreme scenarios.

[0075] If the scheduling command is a discharge command, the battery packs in the second and third states are identified as target battery packs; if the scheduling command is a charging command, the battery packs in the second and first states are identified as target battery packs. This reasonable grouping of battery pack states based on their state of charge can adapt to various types of energy storage systems and battery management systems.

[0076] One method for determining the state of each battery pack is as follows:

[0077] If the state of charge of the battery pack is less than the preset state of charge limit (SOC) min This confirms that the battery pack is in the first state.

[0078] If the state of charge of the battery pack is not less than the preset state of charge limit (SOC) min And not greater than the preset upper limit of state of charge (SOC) max This confirms that the battery pack is in the second state.

[0079] If the state of charge of the battery pack is greater than the preset upper limit of the state of charge (SOC) max This confirms that the battery pack is in the third state.

[0080] The above preset state of charge (SOC) limits min Preset upper limit of state of charge (SOC) max All are preset thresholds, with the preset State of Charge (SOC) as the minimum value. min Preset upper limit of state of charge (SOC) max Configure according to the actual application scenario, such as preset state of charge (SOC) limit. min It can be set to 10%, with a preset upper limit for the state of charge (SOC). max It can be 90%.

[0081] Furthermore, the scheduling margin of the battery pack in each state can be set. The scheduling margin represents the state of charge value that the battery pack can be scheduled for. If the power scheduling command is a discharge command, the energy storage converter executes the discharge command, and the scheduling margin is the discharge margin; if the power scheduling command is a charging command, the energy storage converter executes the charging command, and the scheduling margin is the charging margin.

[0082] like Figure 4 As shown, if the state of charge (SOC) of the battery pack satisfies 0 ≤ SOC(t) < SOC min Under certain conditions, the battery pack is in its first state, with a discharge margin of SOC. d，I (t) and SOC (State of Charge) c，I (t) are respectively:

[0083]

[0084] If the state of charge (SOC) of the battery pack satisfies SOC min ≤SOC(t)≤SOC max Under certain conditions, the battery pack is in its second state, with a discharge margin of SOC. d，II (t) and SOC (State of Charge) c，II (t) are respectively:

[0085]

[0086] If the state of charge (SOC) of the battery pack satisfies SOC max When the condition ≤SOC(t)≤1 is met, the battery pack is in the third state, and its discharge margin SOC is... d，III (t) and absolute charge margin SOC c，III (t) are respectively:

[0087]

[0088] 302: Based on the total dispatch power of the power dispatch command and the rated power of each target battery pack, determine the dispatchable battery packs among the target battery packs whose total rated power meets the power dispatch requirements, and determine the dispatch power of the dispatchable battery packs.

[0089] For example, if the power dispatch command is a discharge command, the target battery packs are sorted in descending order of state of charge. Multiple target battery packs whose total rated power meets the power dispatch requirements are identified as dispatchable battery packs. If the power dispatch command is a charging command, the target battery packs are sorted in ascending order of state of charge. Multiple target battery packs whose total rated power meets the power dispatch requirements are identified as dispatchable battery packs. If the total rated power of the dispatchable battery packs is not less than the total dispatch power of the power dispatch command, the total dispatch power is proportionally allocated according to the dispatch margin of the dispatchable battery packs to determine the dispatch power of the dispatchable battery packs. If the total rated power of the dispatchable battery packs is less than the total dispatch power of the power dispatch command, the rated power of the dispatchable battery packs is determined as the dispatch power of the dispatchable battery packs.

[0090] For example, firstly, based on the type of scheduling instruction, the scheduling priority of target battery packs in different states is determined. The scheduling priority includes a first priority and a second priority, with the first priority being higher than the second priority. If the power scheduling instruction is a discharge instruction, the target battery pack in the third state has the first priority, and the target battery pack in the second state has the second priority; if the power scheduling instruction is a charging instruction, the target battery pack in the first state has the first priority, and the target battery pack in the second state has the second priority. Then, based on the scheduling priority, the schedulable battery packs among the target battery packs whose total rated power meets the power scheduling requirements are determined, and the scheduling power of the schedulable battery packs is determined.

[0091] 303: Send a control command carrying the dispatch power to the energy storage converter connected to the dispatchable battery pack based on the dispatchable battery pack's dispatch power.

[0092] The energy storage converter executes control commands to charge or discharge the schedulable battery pack until it receives a termination command to stop the charging and discharging control of the schedulable battery pack.

[0093] The following examples illustrate the control methods for energy storage systems under different power dispatch scenarios:

[0094] Scene 1

[0095] If the total rated power of the target battery pack with the first scheduling priority is not less than the total scheduling power, the target battery pack with the first scheduling priority is determined as a dispatchable battery pack, and the total scheduling power is proportionally allocated according to the scheduling margin of the dispatchable battery pack to determine the scheduling power of the dispatchable battery pack. Specifically, if the power scheduling command is a discharge command, and the target battery pack in the third state has the first priority, then the target battery pack in the third state is a dispatchable battery pack, and the scheduling power is determined according to the discharge margin (SOC) of the dispatchable battery pack. d，III(t) The total dispatch power is proportionally allocated to determine the dispatch power of the dispatchable battery packs. Taking the dispatchable battery packs including battery pack 1 and battery pack 2 as an example, if the state of charge of battery pack 1 is 80% and the state of charge of battery pack 2 is 90%, the power dispatch command is a discharge command, and the total dispatch power is x, then the discharge power of battery pack 1 is 80x / 170, and the discharge power of battery pack 2 is 90x / 170. That is, the discharge power of battery pack 1 is less than the discharge power of battery pack 2. As the discharge proceeds, the state of charge of battery pack 1 and battery pack 2 can reach dynamic equilibrium.

[0096] This example determines the scheduling power of the scheduling battery packs by proportionally allocating the total scheduling power according to the scheduling margin of the scheduling battery packs, thereby achieving dynamic balance of the state of charge of each battery pack and improving the operational safety and reliability of each battery pack and the energy storage converter.

[0097] Scene 2

[0098] If the total rated power of the target battery pack with the first scheduling priority is less than the total scheduling power, the target battery pack with the first scheduling priority cannot meet the power scheduling requirements. The target battery pack is then determined as a schedulable battery pack. That is, both the target battery packs with the first scheduling priority and the target battery packs with the second scheduling priority are schedulable battery packs. For ease of description, the schedulable battery pack with the first scheduling priority is called the first schedulable battery pack, and the schedulable battery pack with the second scheduling priority is called the second schedulable battery pack.

[0099] If the total rated power of the dispatchable battery pack is not less than the total dispatchable power, the difference between the total dispatchable power and the total rated power of the first dispatchable battery pack is determined as the remaining dispatchable power. Since the first dispatchable battery pack has a strong charging and discharging capability, it is made to perform full power dispatch. The rated power of the first dispatchable battery pack is determined as the dispatchable power of the first dispatchable battery pack. The remaining dispatchable power is distributed proportionally according to the dispatch margin of the second dispatchable battery pack to determine the dispatchable power of the second dispatchable battery pack. This enables the second dispatchable battery pack to achieve dynamic balance of state of charge during the power dispatch process, as well as dynamic balance of state of charge of each battery pack in the entire energy storage system.

[0100] Scene 3

[0101] If the total rated power of the target battery pack with the first scheduling priority is less than the total scheduling power, the target battery pack is determined as a schedulable battery pack. That is, both the target battery packs with the first scheduling priority and the target battery pack with the second scheduling priority are schedulable battery packs. If the total rated power of the schedulable battery pack is less than the total scheduling power, the rated power of the schedulable battery pack is determined as the scheduling power of the schedulable battery pack.

[0102] It should be noted that although the total rated power of the dispatchable battery pack is less than the total dispatchable power, in this scenario, the dispatchable battery pack is already the only dispatchable battery pack in the energy storage system. When all of them are dispatched according to their rated power, the system considers that they meet the power dispatch requirements corresponding to the power dispatch command.

[0103] Based on the above three scenarios, the energy storage system control method provided in this embodiment includes the following steps:

[0104] 501: Determine the state of each battery pack based on its state of charge.

[0105] 502: Determine the type of power scheduling command;

[0106] If the power scheduling is executed as a discharge command, execute 503: Determine whether the total rated discharge power of the dischargeable but non-rechargeable battery pack is less than the total scheduling power;

[0107] 504: If the total rated discharge power of the non-rechargeable battery pack is not less than the total dispatch power, the total dispatch power shall be proportionally allocated according to the discharge margin of the non-rechargeable battery pack to determine the discharge power of the non-rechargeable battery pack.

[0108] 505: If the total rated discharge power of the dischargeable but non-rechargeable battery pack is less than the total dispatch power, and the total rated discharge power of the dischargeable but non-rechargeable battery pack and the rechargeable and dischargeable battery pack is not less than the total dispatch power, the rated discharge power of the dischargeable but non-rechargeable battery pack is determined as its discharge power, and the dischargeable but non-rechargeable battery pack is discharged according to the rated discharge power. The difference between the total dispatch power and the total rated discharge power of the dischargeable but non-rechargeable battery pack is determined as the remaining dispatch power. The remaining dispatch power is distributed proportionally according to the discharge margin of the rechargeable and dischargeable battery pack to determine the discharge power of the rechargeable and dischargeable battery pack.

[0109] 506: If the total rated discharge power of the non-rechargeable battery pack and the rechargeable battery pack is less than the total dispatch power, the rated discharge power of the non-rechargeable battery pack and the rechargeable battery pack shall be determined as their respective discharge power, and the non-rechargeable battery pack and the rechargeable battery pack shall be discharged according to their rated discharge power.

[0110] If the power scheduling command is a charging command, execute 507: Determine whether the total rated charging power of the rechargeable but non-dischargeable battery pack is less than the total scheduling power;

[0111] 508: If the total rated charging power of the rechargeable but non-dischargeable battery pack is not less than the total dispatch power, the total dispatch power shall be proportionally allocated according to the charging margin of the rechargeable but non-dischargeable battery pack to determine the charging power of the rechargeable but non-dischargeable battery pack.

[0112] 509: If the total rated charging power of the rechargeable but non-dischargeable battery pack is less than the total dispatch power, and the total rated charging power of the rechargeable but non-dischargeable battery pack and the rechargeable and dischargeable battery pack is not less than the total dispatch power, the rated charging power of the rechargeable but non-dischargeable battery pack is determined as its charging power, and the rechargeable but non-dischargeable battery pack is discharged according to the rated charging power. The difference between the total dispatch power and the total rated charging power of the rechargeable but non-dischargeable battery pack is determined as the remaining dispatch power. The remaining dispatch power is distributed proportionally according to the charging margin of the rechargeable and dischargeable battery pack to determine the charging power of the rechargeable and dischargeable battery pack.

[0113] 510: If the total rated charging power of the rechargeable but non-dischargeable battery pack and the rechargeable and dischargeable battery pack is less than the total dispatch power, the rated charging power of the rechargeable but non-dischargeable battery pack and the rechargeable and dischargeable battery pack shall be determined as their respective charging power, and the rechargeable but non-dischargeable battery pack and the rechargeable and dischargeable battery pack shall be discharged according to the rated charging power.

[0114] Among them, the battery pack that can be discharged but not recharged is the battery pack in the third state, the battery pack that can be both discharged and recharged is the battery pack in the second state, and the battery pack that can be recharged but not discharged is the battery pack in the first state.

[0115] The energy storage system control method disclosed in this embodiment classifies the schedulable battery pack and the energy storage converter connected to the schedulable battery pack according to the discharge condition and the charging condition, and can perform power optimization allocation for different operating conditions.

[0116] The energy storage system control method disclosed in this embodiment focuses on both economic efficiency and dispatchability when implementing power optimization allocation. On the one hand, considering economic efficiency, to reduce the total operating cost of the energy storage system and maximize the charging and discharging capabilities of each battery pack, power optimization allocation is performed with the goal of minimizing the total operating cost, even when there are differences in the state of charge (SOC) of the battery packs. Specifically, under different charging and discharging conditions, dispatchable battery packs with a total rated power that meets the power dispatch requirements are determined from the target battery packs according to dispatch priority. This ensures that the SOC of each battery pack reaches a dynamic balance after power dispatch, avoiding the problem of insufficient charging and discharging capabilities due to the bottleneck effect, which would increase the total operating cost of the energy storage system. On the other hand, considering dispatchability, during power optimization allocation, discharging is not allowed when the SOC of a battery pack is below a preset lower limit, and charging is not allowed when the SOC of a battery pack is above a preset lower limit. This prevents individual battery packs from reaching their upper or lower limits prematurely, increasing the total dispatchable battery capacity. By optimizing power allocation with economic efficiency and dispatchability as optimization objectives, the sustainable dispatchability and high-efficiency output of the energy storage system are guaranteed.

[0117] The above describes an energy storage system control method provided by the embodiments of this application. The following will describe the apparatus for performing the above-described energy storage system control method.

[0118] An energy storage system control device provided in this application includes:

[0119] A dispatchable battery pack determination unit is used to respond to a power dispatch command and, when there are differences in the state of charge of each battery pack in the energy storage system, determine the dispatchable battery pack in the energy storage system and the dispatchable power of the dispatchable battery pack, wherein the state of charge and total rated power of the dispatchable battery pack meet the power dispatch requirements corresponding to the power dispatch command.

[0120] The control command sending unit is used to send control commands carrying scheduling power to the energy storage converter connected to the schedulable battery pack.

[0121] In one possible implementation, the schedulable battery pack determination unit includes:

[0122] The target battery pack determination subunit is used to determine the target battery pack whose state of charge meets the power scheduling requirements in each battery pack according to the type of the power scheduling command and the state of charge of each battery pack. The type of the power scheduling command includes a discharge command and a charging command.

[0123] The schedulable battery pack determination subunit is used to determine, based on the total schedulable power of the power scheduling command and the rated power of each target battery pack, the schedulable battery pack whose total rated power meets the power scheduling requirements, and to determine the schedulable power of the schedulable battery pack.

[0124] In one possible implementation, the target battery pack determining subunit is specifically used to determine the battery pack with a state of charge not less than a preset upper limit value of the state of charge as the target battery pack if the type of the scheduling instruction is a discharge instruction; and to determine the battery pack with a state of charge not greater than a preset upper limit value of the state of charge as the target battery pack if the type of the scheduling instruction is a charging instruction.

[0125] In one possible implementation, the target battery pack determining sub-unit is specifically used to determine the state of each battery pack based on its state of charge (SOC). The states of the battery packs include a first state, a second state, and a third state. Battery packs in the first state are preferentially charged, battery packs in the second state can be charged or discharged, and battery packs in the third state are preferentially discharged. If the scheduling instruction is a discharge instruction, the battery packs in the second state and the battery packs in the third state are determined as the target battery pack. If the scheduling instruction is a charging instruction, the battery packs in the second state and the battery packs in the first state are determined as the target battery pack.

[0126] In one possible implementation, the schedulable battery pack determination unit is specifically used for:

[0127] Based on the type of the scheduling instruction, the scheduling priority of the target battery pack in different states is determined. The scheduling priority includes a first priority and a second priority, wherein the first priority is higher than the second priority.

[0128] If the total rated power of the target battery pack with the first scheduling priority is not less than the total scheduling power, the target battery pack with the first scheduling priority is determined as the schedulable battery pack, and the total scheduling power is proportionally allocated according to the scheduling margin of the schedulable battery pack to determine the scheduling power of the schedulable battery pack; if the type of the scheduling instruction is a discharge instruction, the scheduling margin is a discharge margin; if the type of the scheduling instruction is a charging instruction, the scheduling margin is a charging margin.

[0129] If the total rated power of the target battery pack with the first scheduling priority is less than the total scheduling power, the target battery pack is determined as the schedulable battery pack, wherein the schedulable battery pack with the first scheduling priority is the first schedulable battery pack, and the schedulable battery pack with the second scheduling priority is the second schedulable battery pack.

[0130] If the total rated power of the dispatchable battery pack is not less than the total dispatchable power, the difference between the total dispatchable power and the total rated power of the first dispatchable battery pack is determined as the remaining dispatchable power, the rated power of the first dispatchable battery pack is determined as the dispatchable power of the first dispatchable battery pack, and the remaining dispatchable power is proportionally allocated according to the dispatch margin of the second dispatchable battery pack to determine the dispatchable power of the second dispatchable battery pack.

[0131] If the total rated power of the schedulable battery pack is less than the total schedulable power, the rated power of the schedulable battery pack is determined as the schedulable power of the schedulable battery pack.

[0132] This embodiment discloses an energy storage system control device that, in response to a power dispatch command, determines the dispatchable battery groups and their dispatch power in response to power dispatch commands when there are differences in the state of charge (SOC) of the various battery groups in the energy storage system. This is achieved by comprehensively analyzing the power dispatch requirements corresponding to the power dispatch command, as well as the SOC and rated power of each battery group. The goal is to ensure that the SOC and total rated power of the dispatchable battery groups meet the power dispatch requirements corresponding to the power dispatch command. The device then sends a control command carrying the dispatch power to the energy storage converter connected to the dispatchable battery groups. This prevents the undispatchable battery groups from reaching their upper or lower limits prematurely due to power dispatch, thereby achieving optimized power allocation and dynamic balance of the SOC of the battery groups, and increasing the total dispatchable battery capacity.

[0133] This application also provides a computer program product including computer-readable instructions, which, when executed on a controller, cause the controller to implement any of the energy storage system control methods provided in this application.

[0134] This application also provides a computer-readable storage medium carrying one or more computer programs. When the one or more computer programs are executed by a controller, the controller can implement any of the energy storage system control methods provided in this application.

[0135] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0137] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0138] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

Claims

1. A control method for an energy storage system, characterized in that, include: In response to a power dispatch command, when there are differences in the state of charge of each battery pack in the energy storage system, the dispatchable battery packs in the energy storage system and the dispatchable power of the dispatchable battery packs are determined, and the state of charge and total rated power of the dispatchable battery packs meet the power dispatch requirements corresponding to the power dispatch command. Send a control command carrying the scheduled power to the energy storage converter connected to the schedulable battery pack.

2. The energy storage system control method according to claim 1, characterized in that, Determining the schedulable battery packs in the energy storage system and the schedulable power of the schedulable battery packs includes: Based on the type of the power scheduling command and the state of charge of each battery pack, a target battery pack whose state of charge meets the power scheduling requirements is determined in each battery pack. The types of the power scheduling command include discharge command and charging command. Based on the total dispatch power of the power dispatch command and the rated power of each target battery pack, determine the dispatchable battery packs among the target battery packs whose total rated power meets the power dispatch requirements, and determine the dispatch power of the dispatchable battery packs.

3. The energy storage system control method according to claim 2, characterized in that, The step of determining the target battery pack whose state of charge meets the power scheduling requirements based on the type of the power scheduling instruction and the state of charge of each battery pack includes: If the type of the scheduling instruction is a discharge instruction, the battery pack whose state of charge is not less than the preset state of charge lower limit is determined as the target battery pack; If the type of the scheduling instruction is a charging instruction, the battery pack whose state of charge is not greater than the preset upper limit of the state of charge is determined as the target battery pack.

4. The energy storage system control method according to claim 2, characterized in that, The step of determining the target battery pack whose state of charge meets the power scheduling requirements based on the type of the power scheduling instruction and the state of charge of each battery pack includes: The state of each battery pack is determined according to its state of charge, and the states of the battery packs include: a first state, a second state, and a third state; the battery pack in the first state is preferentially charged, the battery pack in the second state can be charged or discharged, and the battery pack in the third state is preferentially discharged. If the type of the scheduling instruction is a discharge instruction, the battery pack in the second state and the battery pack in the third state are determined as the target battery pack; If the scheduling instruction is a charging instruction, the battery pack in the second state and the battery pack in the first state are identified as the target battery pack.

5. The energy storage system control method according to claim 4, characterized in that, Determining the state of each battery pack based on its state of charge includes: If the state of charge of the battery pack is less than a preset state of charge limit, the battery pack is determined to be in the first state. If the state of charge of the battery pack is not less than the preset lower limit of the state of charge and not greater than the preset upper limit of the state of charge, the battery pack is determined to be in the second state; If the state of charge of the battery pack is greater than the preset upper limit of the state of charge, the battery pack is determined to be in the third state.

6. The energy storage system control method according to claim 4, characterized in that, The step of determining, based on the total dispatch power of the power dispatch instruction and the rated power of each of the target battery packs, the dispatchable battery packs whose total rated power meets the power dispatch requirements, and determining the dispatch power of the dispatchable battery packs, includes: Based on the type of the scheduling instruction, the scheduling priority of the target battery pack in different states is determined. The scheduling priority includes a first priority and a second priority, wherein the first priority is higher than the second priority. If the total rated power of the target battery pack with the first scheduling priority is not less than the total scheduling power, the target battery pack with the first scheduling priority is determined as the schedulable battery pack, and the total scheduling power is proportionally allocated according to the scheduling margin of the schedulable battery pack to determine the scheduling power of the schedulable battery pack; if the type of the scheduling instruction is a discharge instruction, the scheduling margin is a discharge margin; if the type of the scheduling instruction is a charging instruction, the scheduling margin is a charging margin.

7. The energy storage system control method according to claim 4, characterized in that, The step of determining, based on the total dispatch power of the power dispatch instruction and the rated power of each of the target battery packs, the dispatchable battery packs whose total rated power meets the power dispatch requirements, and determining the dispatch power of the dispatchable battery packs, includes: If the total rated power of the target battery pack with the first scheduling priority is less than the total scheduling power, the target battery pack is determined as the schedulable battery pack, wherein the schedulable battery pack with the first scheduling priority is the first schedulable battery pack, and the schedulable battery pack with the second scheduling priority is the second schedulable battery pack. If the total rated power of the dispatchable battery pack is not less than the total dispatchable power, the difference between the total dispatchable power and the total rated power of the first dispatchable battery pack is determined as the remaining dispatchable power, the rated power of the first dispatchable battery pack is determined as the dispatchable power of the first dispatchable battery pack, and the remaining dispatchable power is proportionally allocated according to the dispatch margin of the second dispatchable battery pack to determine the dispatchable power of the second dispatchable battery pack. If the total rated power of the schedulable battery pack is less than the total schedulable power, the rated power of the schedulable battery pack is determined as the schedulable power of the schedulable battery pack.

8. The energy storage system control method according to claim 6, characterized in that, The discharge margin of the battery pack in the first state is the state of charge, and the charging margin is the difference between the preset upper limit of the state of charge and the state of charge. The discharge margin of the battery pack in the second state is the difference between the state of charge and the preset upper limit of the state of charge, and the charging margin is the difference between the preset upper limit of the state of charge and the state of charge. The discharge margin of the battery pack in the third state is the difference between the state of charge and the preset state of charge limit, and the charging margin is the difference between 1 and the state of charge.

9. A controller, characterized in that, It includes at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the controller can implement the energy storage system control method as described in any one of claims 1 to 8.

10. An energy storage system, characterized in that, include: A controller, multiple battery packs, and an energy storage converter connected to each of the battery packs; The controller is used to execute the energy storage system control method according to any one of claims 1 to 8; The energy storage converter is used to execute the control commands sent by the controller.

11. A computer program product, characterized in that, Includes computer-readable instructions that, when executed on a controller, cause the controller to implement the energy storage system control method as described in any one of claims 1 to 8.

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