Energy storage system charging and discharging control method, controller and energy storage system

Abstract

This invention provides a charging and discharging control method, controller, and energy storage system for an energy storage system. The method includes: acquiring the power data of all online battery cells in the energy storage system and the initial charging and discharging parameter setpoints of the current online battery cell; calculating the average power of all online battery cells; correcting the initial charging and discharging parameter setpoints of the current online battery cell based on the power data and the average power, obtaining the final charging and discharging parameter setpoints of the online battery cell, and performing charging and discharging control on the current online battery cell based on the final charging and discharging parameter setpoints. Based on the above method, this application can balance the power of each battery cell during charging and discharging, thereby not only solving the problem of power imbalance among multiple battery cells but also improving the timeliness of battery balancing.

Description

Technical Field

[0001] This invention relates to the field of energy storage control technology, and in particular to a charging and discharging control method, controller and energy storage system for an energy storage system. Background Technology

[0002] In recent years, energy storage battery systems have developed rapidly, moving towards higher capacity, higher power density, and higher power integration. Typically, an energy storage system consists of multiple battery modules connected in parallel, and each battery module is composed of a different number of individual battery cells connected in series and parallel.

[0003] As the operating time of energy storage batteries continues to increase, the internal resistance difference of each battery cluster will also increase, leading to inconsistent battery cluster capacity during charging and discharging, which in turn reduces the usable capacity of the energy storage system.

[0004] To balance the remaining available capacity of multiple battery modules, existing methods often employ active balancing. When the energy storage system is in standby mode, battery modules with larger remaining capacity charge battery modules with smaller remaining capacity. However, this method can only operate when the energy storage system is not undergoing charging or discharging tasks, resulting in poor balancing timeliness. Summary of the Invention

[0005] This invention provides a charging and discharging control method, controller, and energy storage system for energy storage systems, in order to solve the problem of poor battery balancing timeliness in energy storage systems.

[0006] In a first aspect, embodiments of the present invention provide a charging and discharging control method for an energy storage system, the energy storage system comprising multiple battery cells and a converter module; each battery cell is respectively connected to its corresponding converter module; the method is applied to the converter module; the method includes:

[0007] Acquire the power data of all online battery cells in the energy storage system and the initial charge and discharge parameter setpoints of the current online battery cell, wherein the current online battery cell is any online battery cell in the energy storage system;

[0008] Calculate the average charge level of all online battery cells;

[0009] Based on the current online battery cell's power data and the average power value, the initial charge and discharge parameter setpoints of the current online battery cell are corrected to obtain the final charge and discharge parameter setpoints of the current online battery cell, and the charge and discharge control of the current online battery cell is performed based on the final charge and discharge parameter setpoints.

[0010] In a second aspect, embodiments of the present invention provide a controller, 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 steps of the charging and discharging control method of the energy storage system as described in any possible implementation of the first aspect above.

[0011] Thirdly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the charging and discharging control method of the energy storage system as described in any possible implementation of the first aspect above.

[0012] Fourthly, embodiments of the present invention provide an energy storage system, including an energy storage converter, multiple battery cells, a converter module corresponding to each battery cell, and a controller as described in the second aspect above corresponding to each converter module; each battery cell is connected to the first end of its corresponding converter module, and the second end of each converter module is connected to the DC end of the energy storage converter; the AC end of the energy storage converter is the output end of the energy storage system.

[0013] Fifthly, embodiments of the present invention provide an energy storage system, including multiple energy storage converter modules, each energy storage converter module including a battery unit, an energy storage converter and a controller as described in the second aspect above for each energy storage converter;

[0014] Each battery cell is connected to the DC terminal of its corresponding energy storage converter, and the AC terminals of each energy storage converter are connected in parallel to serve as the output terminal of the energy storage system.

[0015] This invention provides a charging and discharging control method, controller, and energy storage system for an energy storage system. The method first acquires the power data of all online battery cells in the energy storage system and the initial charging and discharging parameter setpoints for the current online battery cell; then, it calculates the average power of all online battery cells; based on the power data and average power of the current online battery cell, it corrects the initial charging and discharging parameter setpoints for the current online battery cell to obtain the final charging and discharging parameter setpoints for the online battery cell; and then, it performs charging and discharging control on the current online battery cell based on the final charging and discharging parameter setpoints. Based on the above method, this embodiment can balance the power of each battery cell during the charging and discharging process, thereby not only solving the problem of power imbalance among multiple battery cells but also improving the timeliness of battery balancing. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a structure of an energy storage system provided in an embodiment of the present invention;

[0018] Figure 2 This is another structural schematic diagram of the energy storage system provided in the embodiment of the present invention;

[0019] Figure 3 This is a flowchart illustrating the implementation of the charging and discharging control method for the energy storage system provided in this embodiment of the invention.

[0020] Figure 4 This is a schematic diagram of the charging and discharging control device of the energy storage system provided in an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the controller provided in an embodiment of the present invention. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0024] Figure 1 This diagram illustrates an application scenario of the charging and discharging control method for an energy storage system provided in an embodiment of the present invention. For example... Figure 1 As shown, the energy storage system includes multiple battery cells and a converter module; each battery cell is connected to its corresponding converter module; the method is applied to the converter module.

[0025] Specifically, such as Figure 1 As shown, the energy storage system also includes an energy storage converter. The converter module can be a DC-DC module. Each battery cell is connected to one end of the corresponding DC-DC module. The other end of each DC-DC module is connected to the DC bus. The DC bus is connected to the DC end of the energy storage converter. The AC end is used to connect to the load or the power grid. The controller is used to control the operation of the DC-DC module.

[0026] Specifically, the controllers corresponding to the DC-DC modules communicate with each other, and the controller corresponding to each DC-DC module communicates with the monitoring host of the energy storage system.

[0027] Specifically, such as Figure 2 As shown, another component structure of the energy storage system includes multiple energy storage converter modules. Each energy storage converter module includes a battery cell and an energy storage converter. Each battery cell is connected to the DC side of its corresponding energy storage converter, and the AC side of each energy storage converter is connected to the load or the power grid. The controller is used to control the operation of the energy storage converter.

[0028] Specifically, the controllers corresponding to the energy storage converters are connected to each other, and the controller corresponding to each energy storage converter is connected to the monitoring host of the energy storage system.

[0029] See Figure 3 The flowchart illustrating the implementation of the charging and discharging control method for the energy storage system provided in this embodiment of the invention is described in detail below:

[0030] S101: Obtain the power data of all online battery cells in the energy storage system and the initial charge / discharge parameter setpoint of the current online battery cell, wherein the current online battery cell is any online battery cell in the energy storage system.

[0031] The execution subject of this embodiment is Figure 1 The controller of the DCDC module shown Figure 2 The controller corresponding to the energy storage converter shown.

[0032] Specifically, before performing charge balancing on the battery cells, it is first necessary to identify the online battery cells in the energy storage system. The specific process for identifying the online battery cells is as follows:

[0033] For any battery cell in the energy storage system, if the target output power of the battery cell exceeds the maximum usable power of the battery cell, the operating state of the battery cell is determined to be a limited state.

[0034] If no broadcast data is detected from the battery unit for a continuous first preset time, the battery unit is determined to be in an offline state.

[0035] If the battery cell is found to be not in normal operation or offline for a continuous second preset time, the battery cell is determined to be in an abnormal operating state.

[0036] If the battery cell is neither in a limited state nor in an abnormal state, then the battery cell is determined to be an online battery cell.

[0037] After identifying the online battery cells in the energy storage system, the controller acquires the corresponding online battery cell's power data in real time. This power data may include SOC (State of Charge), voltage, or power. Once the controller acquires the corresponding power data, it can send this data to the controllers of other online battery cells, ensuring that all controllers of the online battery cells can monitor the power data of each online battery cell in the energy storage system.

[0038] In one possible implementation, the charge / discharge parameters include charge / discharge power; the method for obtaining the initial charge / discharge parameter setpoint in S101 specifically includes:

[0039] Obtain the initial charge / discharge power setpoint issued by the controller of the energy storage system; the initial charge / discharge power setpoint is obtained by dividing the total charge / discharge power setpoint of the energy storage system by the number of online battery cells.

[0040] In this embodiment, the monitoring host of the energy storage system is used to determine the total charge and discharge parameters of the energy storage system, which may include charge and discharge power and charge and discharge current. Then, the total charge and discharge power is divided by the number of online battery cells to obtain the initial charge and discharge power setpoint for each online battery cell. Finally, the initial charge and discharge power setpoint is sent to the controller corresponding to the online battery cell.

[0041] S102: Calculate the average charge level of all online battery cells.

[0042] In this embodiment, the SOC value of all online battery cells is averaged to obtain the average power capacity.

[0043] S103: Based on the current online battery cell's power data and the average power value, correct the initial charge / discharge parameter setpoint of the current online battery cell to obtain the final charge / discharge parameter setpoint of the current online battery cell, and perform charge / discharge control on the current online battery cell based on the final charge / discharge parameter setpoint.

[0044] In one possible implementation, the specific implementation process of S103 includes:

[0045] S201: If the current online battery cell's power data is greater than the average power value, then the initial charge / discharge parameter setpoint of the current online battery cell is reduced to obtain the final charge / discharge parameter setpoint of the current online battery cell.

[0046] S202: If the current online battery cell's charge data is less than the average charge value, then increase the initial charge / discharge parameter setpoint of the current online battery cell to obtain the final charge / discharge parameter setpoint of the current online battery cell.

[0047] In this embodiment, when the charging / discharging power is positive, the grid charges the battery cell; when the charging / discharging power is negative, the battery cell discharges. When the energy storage system is charging, for any online battery cell, if the battery cell's charge level is greater than the average charge level, the initial charging / discharging parameter setpoint for that online battery cell is reduced to obtain the final charging / discharging parameter setpoint. If the battery cell's charge level is less than the average charge level, the initial charging / discharging parameter setpoint for that online battery cell is increased.

[0048] When the energy storage system is in a discharging state, for any online battery cell, if the charge data of the online battery cell is greater than the average charge value, since the charge and discharge parameters are negative at this time, the initial charge and discharge parameter setpoint of the online battery cell needs to be reduced to obtain the final charge and discharge parameter setpoint. Similarly, if the charge data of the battery cell is less than the average charge value, since the charge and discharge parameters are negative at this time, the initial charge and discharge parameter setpoint of the online battery cell needs to be increased.

[0049] In one possible implementation, the specific implementation process of S201 includes:

[0050] If the current online battery cell's power data is greater than the average power value, then the current online battery cell's power data is subtracted from the average power value to obtain the power difference.

[0051] A first parameter compensation value is determined based on the power difference and the operating state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the operating state includes charging state and discharging state.

[0052] The initial charge / discharge parameter setpoint of the current online battery cell is added to the first parameter compensation value to obtain the final charge / discharge parameter setpoint of the current online battery cell.

[0053] In this embodiment, when the energy storage system is charging, the initial charge / discharge power setpoint is positive. If the current online battery cell's charge level is greater than the average charge level, the initial charge / discharge power setpoint needs to be reduced. Furthermore, the greater the difference between the current online battery cell's charge level and the average charge level, the greater the downward adjustment of the initial charge / discharge power setpoint; that is, the charge level difference is negatively correlated with the first parameter compensation value. Conversely, if the current online battery cell's charge level is less than the average charge level, the initial charge / discharge power setpoint needs to be increased. Furthermore, the greater the difference between the current online battery cell's charge level and the average charge level, the greater the upward adjustment of the initial charge / discharge power setpoint; that is, the charge level difference is positively correlated with the first parameter compensation value.

[0054] When the energy storage system is in discharge mode, the initial charge / discharge power setpoint is negative. If the current online battery cell's charge level is greater than the average charge level, the initial charge / discharge power setpoint needs to be reduced. Furthermore, the greater the difference between the current online battery cell's charge level and the average charge level, the greater the downward adjustment of the initial charge / discharge power setpoint. In other words, the charge level difference is negatively correlated with the first parameter compensation value. Conversely, if the current online battery cell's charge level is less than the average charge level, the initial charge / discharge power setpoint needs to be increased. Furthermore, the greater the difference between the current online battery cell's charge level and the average charge level, the greater the upward adjustment of the initial charge / discharge power setpoint. In other words, the charge level difference is positively correlated with the first parameter compensation value.

[0055] Specifically, to avoid frequent changes in the charging and discharging power setpoint of the battery cell, this embodiment sets the first parameter compensation value to zero when the power difference is within a preset power range, meaning the initial charging and discharging power setpoint is not adjusted. The preset power range can be -5% to +5% or -7% to +7%, and the specific value can be set according to actual conditions.

[0056] In one possible implementation, another step in S103 includes:

[0057] If the energy storage system is in a charging state, the amount of data to be charged is obtained based on the current power data of the online battery cells, and the average amount of data to be charged is obtained based on the average power data.

[0058] Divide the amount of charge to be charged by the average amount of charge to be charged to obtain the first ratio.

[0059] Multiply the initial charge / discharge parameter setpoint by the first ratio to obtain the final charge / discharge parameter setpoint of the current online battery cell;

[0060] If the energy storage system is in a discharging state, the current online battery cell's charge data is divided by the average charge value to obtain a second ratio.

[0061] Multiplying the initial charge / discharge parameter setpoint by the second ratio yields the final charge / discharge parameter setpoint for the current online battery cell.

[0062] Specifically, the amount of charge to be collected is obtained by subtracting the current online battery cell's capacity from its full-scale value. This method adjusts the charging and discharging parameters of the corresponding online battery cell based on the ratio of the amount of charge each cell can take in to the average amount of charge to be collected, or the ratio of the amount of charge it can release to the average amount of charge. This achieves capacity balancing among the battery cells during the charging and discharging process of the energy storage system, improving the timeliness of capacity balancing.

[0063] In one possible implementation, the charge / discharge parameters include charge / discharge power; S103 involves controlling the charge / discharge of the current online battery cell based on the given final charge / discharge parameter values, including:

[0064] If the absolute value of the final charging power setpoint of the current online battery cell is greater than the charging and discharging power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is increased.

[0065] If the absolute value of the final discharge power setpoint of the current online battery cell is greater than the charge / discharge power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is reduced.

[0066] In this embodiment, the charge / discharge power threshold is the maximum allowable charge / discharge power of the online battery cell. Each battery cell also needs to stabilize the DC bus voltage while charging and discharging. When the energy storage system is charging, if the absolute value of the final charge power setpoint of the current online battery cell is greater than the charge / discharge power threshold of the current online battery cell, the output voltage setpoint of the current online battery cell is increased. When the energy storage system is discharging, if the absolute value of the final discharge power setpoint of the current online battery cell is greater than the charge / discharge power threshold of the current online battery cell, the output voltage setpoint of the current online battery cell is decreased.

[0067] As can be seen from the above embodiments, the charging and discharging control method of the energy storage system provided in this embodiment can not only achieve the balance of power between batteries during the charging and discharging process, but also maintain the stability of the DC bus voltage of each battery unit in the energy storage system.

[0068] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0069] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0070] Figure 4 A schematic diagram of the charging and discharging control device for an energy storage system provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0071] like Figure 4 As shown, the charging and discharging control device 100 of the energy storage system includes:

[0072] The data acquisition module 110 is used to acquire the power data of all online battery cells in the energy storage system and the initial charge and discharge parameter setpoint of the current online battery cell, wherein the current online battery cell is any online battery cell in the energy storage system.

[0073] The average power calculation module 120 is used to calculate the average power of all online battery cells;

[0074] The equalization charge and discharge control module 130 is used to correct the initial charge and discharge parameter setpoint of the current online battery cell according to the power data of the current online battery cell and the average power value, to obtain the final charge and discharge parameter setpoint of the current online battery cell, and to perform charge and discharge control on the current online battery cell based on the final charge and discharge parameter setpoint.

[0075] In one possible implementation, the equalization charge / discharge control module 130 includes:

[0076] The parameter reduction unit is used to reduce the initial charge and discharge parameter setpoint of the current online battery unit if the power data of the current online battery unit is greater than the average power value, so as to obtain the final charge and discharge parameter setpoint of the current online battery unit.

[0077] The parameter adjustment unit is used to increase the initial charge and discharge parameter setpoint of the current online battery unit if the power data of the current online battery unit is less than the average power value, so as to obtain the final charge and discharge parameter setpoint of the current online battery unit.

[0078] In one possible implementation, the parameter reduction unit is specifically used for:

[0079] If the current online battery cell's power data is greater than the average power value, then the current online battery cell's power data is subtracted from the average power value to obtain the power difference.

[0080] A first parameter compensation value is determined based on the power difference and the operating state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the operating state includes charging state and discharging state.

[0081] The initial charge / discharge parameter setpoint of the current online battery cell is added to the first parameter compensation value to obtain the final charge / discharge parameter setpoint of the current online battery cell.

[0082] In one possible implementation, the equalization charge / discharge control module 130 includes:

[0083] If the energy storage system is in a charging state, the amount of data to be charged is obtained based on the current power data of the online battery cells, and the average amount of data to be charged is obtained based on the average power data.

[0084] Divide the amount of charge to be charged by the average amount of charge to be charged to obtain the first ratio.

[0085] Multiply the initial charge / discharge parameter setpoint by the first ratio to obtain the final charge / discharge parameter setpoint of the current online battery cell;

[0086] If the energy storage system is in a discharging state, the current online battery cell's charge data is divided by the average charge value to obtain a second ratio.

[0087] Multiplying the initial charge / discharge parameter setpoint by the second ratio yields the final charge / discharge parameter setpoint for the current online battery cell.

[0088] In one possible implementation, the charge / discharge parameters include charge / discharge power; the equalization charge / discharge control module 130 further includes:

[0089] If the absolute value of the final charging power setpoint of the current online battery cell is greater than the charging and discharging power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is increased.

[0090] If the absolute value of the final discharge power setpoint of the current online battery cell is greater than the charge / discharge power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is reduced.

[0091] In one possible implementation, the charge / discharge parameters include charge / discharge power; the data acquisition module 110 includes:

[0092] Obtain the initial charge / discharge power setpoint issued by the controller of the energy storage system; the initial charge / discharge power setpoint is obtained by dividing the total charge / discharge power setpoint of the energy storage system by the number of online battery cells.

[0093] As can be seen from the above embodiments, this embodiment can balance the power of each battery cell during the charging and discharging process, thereby not only solving the problem of uneven power of multiple battery cells, but also improving the timeliness of battery balancing.

[0094] Figure 5 This is a schematic diagram of a terminal provided in an embodiment of the present invention. Figure 5As shown, the terminal 5 in this embodiment includes a processor 50 and a memory 51. The memory 51 stores a computer program 52, and the processor 50 calls and runs the computer program 52 stored in the memory 51 to execute the steps in the charging and discharging control method embodiments of the various energy storage systems described above, for example... Figure 3 The steps S101 to S103 are shown. Alternatively, the processor 50 is used to call and run the computer program 52 stored in the memory 51 to implement the functions of each module / unit in the above-described device embodiments, for example... Figure 4 The functions of modules 110 to 130 are shown.

[0095] For example, the computer program 52 can be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 52 in the terminal 5. For example, the computer program 52 can be divided into... Figure 4 Modules 110 to 130 are shown.

[0096] The terminal 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that... Figure 5 This is merely an example of terminal 5 and does not constitute a limitation on terminal 5. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal may also include input / output devices, network access devices, buses, etc.

[0097] The processor 50 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0098] The memory 51 can be an internal storage unit of the terminal 5, such as a hard disk or memory of the terminal 5. The memory 51 can also be an external storage device of the terminal 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the terminal 5. Furthermore, the memory 51 can include both internal storage units and external storage devices of the terminal 5. The memory 51 is used to store the computer program and other programs and data required by the terminal. The memory 51 can also be used to temporarily store data that has been output or will be output.

[0099] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0100] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0101] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0102] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0103] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0104] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0105] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the charging and discharging control methods of the various energy storage systems described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0106] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A charging and discharging control method for an energy storage system, characterized in that, The energy storage system includes multiple battery cells and a converter module; each battery cell is connected to its corresponding converter module; the method is applied to the converter module. The method includes: Acquire the power data of all online battery cells in the energy storage system and the initial charge and discharge parameter setpoints of the current online battery cell, wherein the current online battery cell is any online battery cell in the energy storage system; Calculate the average charge level of all online battery cells; Based on the current online battery cell's power data and the average power value, the initial charge and discharge parameter setpoints of the current online battery cell are corrected to obtain the final charge and discharge parameter setpoints of the current online battery cell, and the charge and discharge control of the current online battery cell is performed based on the final charge and discharge parameter setpoints. The charging and discharging parameters include charging power and discharging power; the charging and discharging control of the current online battery cell based on the final given values ​​of the charging and discharging parameters includes: If the absolute value of the final charging power setpoint of the current online battery cell is greater than the charging and discharging power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is increased. If the absolute value of the final discharge power setpoint of the current online battery cell is greater than the charge / discharge power threshold of the current online battery cell, then the output voltage setpoint of the current online battery cell is reduced.

2. The charging and discharging control method for an energy storage system according to claim 1, characterized in that, Based on the current online battery cell's charge data and the average charge value, the initial charge / discharge parameter setpoints for the current online battery cell are corrected to obtain the final charge / discharge parameter setpoints for the current online battery cell, including: If the current online battery cell's charge level is greater than the average charge level, then the initial charge / discharge parameter setpoint of the current online battery cell is reduced to obtain the final charge / discharge parameter setpoint of the current online battery cell. If the current online battery cell's charge level is less than the average charge level, then the initial charge / discharge parameter setpoint of the current online battery cell is increased to obtain the final charge / discharge parameter setpoint of the current online battery cell.

3. The charging and discharging control method for an energy storage system according to claim 2, characterized in that, If the current online battery cell's charge level is greater than the average charge level, then the initial charge / discharge parameter setpoints for the current online battery cell are reduced to obtain the final charge / discharge parameter setpoints for the current online battery cell, including: If the current online battery cell's power data is greater than the average power value, then the current online battery cell's power data is subtracted from the average power value to obtain the power difference. A first parameter compensation value is determined based on the power difference and the operating state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the operating state includes charging state and discharging state. The initial charge / discharge parameter setpoint of the current online battery cell is added to the first parameter compensation value to obtain the final charge / discharge parameter setpoint of the current online battery cell.

4. The charging and discharging control method for an energy storage system according to claim 1, characterized in that, The step of correcting the initial charge / discharge parameter setpoints of the current online battery cell based on the current online battery cell's power data and the average power value, to obtain the final charge / discharge parameter setpoints of the current online battery cell, includes: If the energy storage system is in a charging state, the amount of charge to be obtained is based on the current power data of the online battery cells, and the average amount of charge to be obtained is based on the average power data. Divide the amount of charge to be charged by the average amount of charge to be charged to obtain the first ratio. Multiply the initial charge / discharge parameter setpoint by the first ratio to obtain the final charge / discharge parameter setpoint of the current online battery cell; If the energy storage system is in a discharging state, the current online battery cell's charge data is divided by the average charge value to obtain a second ratio. Multiplying the initial charge / discharge parameter setpoint by the second ratio yields the final charge / discharge parameter setpoint for the current online battery cell.

5. The charging and discharging control method for an energy storage system according to claim 1, characterized in that, Obtain the initial charge and discharge parameter setpoints for the currently online battery cell, including: Obtain the initial charge / discharge power setpoint issued by the controller of the energy storage system; the initial charge / discharge power setpoint is obtained by dividing the total charge / discharge power setpoint of the energy storage system by the number of online battery cells.

6. A controller, characterized in that, It includes a processor and a memory, the memory being used to store computer programs, and the processor being used to call and run the computer programs stored in the memory to execute the charging and discharging control method of the energy storage system as described in any one of claims 1 to 5.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the charging and discharging control method of the energy storage system as described in any one of claims 1 to 5.

8. An energy storage system, characterized in that, It includes an energy storage converter, multiple battery cells, a converter module corresponding to each battery cell, and a controller as described in claim 6 corresponding to each converter module; each battery cell is connected to the first end of its corresponding converter module, and the second end of each converter module is connected to the DC end of the energy storage converter; the AC end of the energy storage converter is the output end of the energy storage system.

9. An energy storage system, characterized in that, It includes multiple energy storage converter modules, each of which includes a battery unit, an energy storage converter, and a controller as described in claim 6 for each energy storage converter; Each battery cell is connected to the DC terminal of its corresponding energy storage converter, and the AC terminals of each energy storage converter are connected in parallel to serve as the output terminal of the energy storage system.

Images