Charging and discharging control method of energy storage system, controller and energy storage system

Abstract

The invention provides a charging and discharging control method of an energy storage system, a controller and the energy storage system. The method comprises the following steps: acquiring electric quantity data of all on-line battery units in the energy storage system and an initial charging and discharging parameter given value of the current on-line battery unit; calculating the average value of the electric quantity of all the on-line battery units; and according to the electric quantity data and the electric quantity average value of the current online battery unit, correcting the initial charging and discharging parameter given value of the current online battery unit to obtain a final charging and discharging parameter given value of the online battery unit, and carrying out charging and discharging control on the current online battery unit based on the final charging and discharging parameter given value. Based on the method, electric quantity equalization can be carried out on each battery unit in the charging and discharging process, so that the problem that the electric quantity of the multiple battery units is unbalanced can be solved, and the timeliness of battery equalization can also be improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage control technology, and in particular to a charge and discharge control method, a controller and an energy storage system. Background Art

[0002] In recent years, energy storage battery systems have developed rapidly, and are moving towards high capacity, high power density, and high power integration. Generally speaking, an energy storage system is often composed of multiple battery modules in parallel, and a battery module is composed of different numbers of single cells in series and parallel.

[0003] As the operating time of the energy storage battery continues to increase, the internal resistance of each cluster of battery modules will become increasingly different, resulting in inconsistent capacity of the battery cluster during charging and discharging, thereby reducing the available capacity of the energy storage system.

[0004] In order to balance the remaining available capacity of multiple battery modules, active balancing methods are currently used. When the energy storage system is in standby mode, battery modules with more remaining battery capacity are used to charge battery modules with less remaining battery capacity. However, this method can only be run when there is no charging or discharging task in the energy storage system, and the balancing timeliness is poor. Summary of the invention

[0005] The embodiments of the present invention provide a charge and discharge control method, a controller and an energy storage system for an energy storage system, so as to solve the problem of poor battery balancing timeliness of the energy storage system.

[0006] In a first aspect, an embodiment of the present invention provides a charge and discharge control method for an energy storage system, wherein the energy storage system comprises a plurality of battery cells and a converter module; each battery cell is respectively connected to a corresponding converter module; the method is applied to the converter module; the method comprises:

[0007] Acquire the power data of all online battery units in the energy storage system and the given values ​​of initial charge and discharge parameters of the current online battery unit, where the current online battery unit is any online battery unit in the energy storage system;

[0008] Calculate the average power of all online battery units;

[0009] According to the power data of the current online battery unit and the average power value, the initial charge and discharge parameter given value of the current online battery unit is corrected to obtain the final charge and discharge parameter given value of the current online battery unit, and the charge and discharge of the current online battery unit is controlled based on the final charge and discharge parameter given value.

[0010] In a second aspect, an embodiment of the present invention provides a controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for controlling charging and discharging of an energy storage system as described in any possible implementation of the first aspect above are implemented.

[0011] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for controlling charging and discharging of an energy storage system as described in any possible implementation of the first aspect above are implemented.

[0012] In a fourth aspect, an embodiment of the present invention provides an energy storage system, comprising an energy storage inverter, a plurality of battery cells, an inverter module corresponding to each battery cell, and a controller as described in the second aspect above corresponding to each inverter module; each battery cell is respectively connected to the first end of the inverter module corresponding to each battery cell, and the second end of each inverter module is connected to the DC end of the energy storage inverter; the AC end of the energy storage inverter is the output end of the energy storage system.

[0013] In a fifth aspect, an embodiment of the present invention provides an energy storage system, comprising a plurality of energy storage converter modules, each of which comprises a battery unit, an energy storage converter, and a controller as described in the second aspect above corresponding to each energy storage converter;

[0014] Each battery unit is connected to a DC terminal of a 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] The embodiment of the present invention provides a charge and discharge control method, controller and energy storage system for an energy storage system. The method first obtains the power data of all online battery cells in the energy storage system and the initial charge and discharge parameter given values ​​of the current online battery cells; then calculates the average power value of all online battery cells; based on the power data and the average power value of the current online battery cells, corrects the initial charge and discharge parameter given values ​​of the current online battery cells to obtain the final charge and discharge parameter given values ​​of the online battery cells, and controls the charge and discharge of the current online battery cells based on the final charge and discharge parameter given values. Based on the above method, the present embodiment can balance the power of each battery cell during the charge and discharge process, thereby not only solving the problem of unbalanced power of multiple battery cells, but also improving the timeliness of battery balancing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

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

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

[0019] Figure 3 is a flow chart of an implementation method of a charge and discharge control method for an energy storage system provided by an embodiment of the present invention;

[0020] Figure 4 is a structural schematic diagram of a charge and discharge control device for an energy storage system provided by an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0024] Figure 1 This is an application scenario diagram of the charge and discharge control method of the energy storage system provided by the embodiment of the present invention. Figure 1 As shown, the energy storage system includes a plurality of battery cells and a converter module; each battery cell is respectively connected to a corresponding converter module; and the method is applied to the converter module.

[0025] Specifically, Figure 1 As shown, the energy storage system also includes an energy storage converter, the converter module can be a DCDC module, each battery unit is connected to one end of the corresponding DCDC module, the other end of each DCDC 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 the load or the power grid, and the controller is used to control the operation of the DCDC module.

[0026] Specifically, the controllers corresponding to the DCDC modules are communicatively connected to each other, and the controller corresponding to each DCDC module is communicatively connected to a monitoring host of the energy storage system.

[0027] Specifically, Figure 2 As shown, another structure of the energy storage system includes multiple energy storage converter modules, each of which includes a battery unit and an energy storage converter. Each battery unit is connected to the DC side of the corresponding energy storage converter, and the AC end 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 communicatively connected to each other, and the controller corresponding to each energy storage converter is communicatively connected to a monitoring host of the energy storage system.

[0029] See also Figure 3 , which shows a flow chart of the implementation of the charge and discharge control method of the energy storage system provided by an embodiment of the present invention, which is described in detail as follows:

[0030] S101: Acquire power data of all online battery units in the energy storage system and given values ​​of initial charge and discharge parameters of a current online battery unit, where the current online battery unit is any online battery unit in the energy storage system.

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

[0032] Specifically, before performing power balancing on the battery cells, it is first necessary to determine the online battery cells in the energy storage system. The specific process for determining 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 available power of the battery cell, determining that the operating state of the battery cell is a limit state;

[0034] If the broadcast data of the battery unit is not detected for a first preset time, it is determined that the battery unit is in an offline state;

[0035] If it is monitored that the battery unit is not in a normal operating state or is in an offline state for a second preset time, the operating state of the battery unit is determined to be an abnormal state;

[0036] If the battery cell is neither in the limit state nor in the abnormal state, it is determined that the battery cell is an online battery cell.

[0037] After determining the online battery unit in the energy storage system, the controller obtains the power data of the corresponding online battery unit in real time, and the power data may include SOC (State of Charge), voltage or power, etc. After obtaining the corresponding power data, the controller may send the power data to the controllers corresponding to other online battery units, so that the controllers of all online battery units can monitor the power data of each online battery unit in the energy storage system.

[0038] In a possible implementation manner, the charging and discharging parameters include charging and discharging power; the method for obtaining the initial charging and discharging parameter given value in S101 specifically includes:

[0039] An initial charge and discharge power given value issued by the controller of the energy storage system is obtained; the initial charge and discharge power given value is obtained by dividing the total charge and discharge power given value of the energy storage system by the number of online battery units.

[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. The total charge and discharge power is then divided by the number of online battery units to obtain the initial charge and discharge power given value of each online battery unit, and finally the initial charge and discharge power given value is sent to the controller corresponding to the online battery unit.

[0041] S102: Calculate the average power of all online battery units.

[0042] In this embodiment, the SOC values ​​of all online battery units are averaged to obtain an average power value.

[0043] S103: According to the power data of the current online battery unit and the average power value, the initial charge and discharge parameter given value of the current online battery unit is corrected to obtain the final charge and discharge parameter given value of the current online battery unit, and the charge and discharge of the current online battery unit is controlled based on the final charge and discharge parameter given value.

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

[0045] S201: If the power data of the current online battery unit is greater than the power average value, reduce the initial charge and discharge parameter given value of the current online battery unit to obtain the final charge and discharge parameter given value of the current online battery unit;

[0046] S202: If the power data of the current online battery unit is less than the power average value, increase the initial charge and discharge parameter given value of the current online battery unit to obtain the final charge and discharge parameter given value of the current online battery unit.

[0047] In this embodiment, when the charge and discharge power is positive, the grid charges the battery unit, and when the charge and discharge power is negative, the battery unit discharges outward. When the energy storage system is in the charging state, for any online battery unit, if the power data of the online battery unit is greater than the average power value, the initial charge and discharge parameter given value of the online battery unit is reduced to obtain the final charge and discharge parameter given value; if the power data of the battery unit is less than the average power value, the initial charge and discharge parameter given value of the online battery unit is increased.

[0048] When the energy storage system is in a discharging state, for any online battery unit, if the power data of the online battery unit is greater than the average power value, since the charge and discharge parameters are negative at this time, it is necessary to reduce the initial charge and discharge parameter given value of the online battery unit to obtain the final charge and discharge parameter given value; similarly, if the power data of the battery unit is less than the average power value, since the charge and discharge parameters are negative at this time, it is necessary to increase the initial charge and discharge parameter given value of the online battery unit.

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

[0050] If the power data of the current online battery unit is greater than the power average value, subtract the power average value from the power data of the current online battery unit to obtain a power difference;

[0051] Determine a first parameter compensation value according to the power difference and the working state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the working state includes a charging state and a discharging state;

[0052] The initial charge and discharge parameter given value of the current online battery unit is added to the first parameter compensation value to obtain a final charge and discharge parameter given value of the current online battery unit.

[0053] In this embodiment, when the energy storage system is in a charging state, the charge and discharge power given value is a positive value. If the power data of the current online battery unit is greater than the power average value, the initial charge and discharge power given value needs to be reduced, and the greater the difference between the power data of the current online battery unit and the power average value, the greater the amount by which the initial charge and discharge power given value is adjusted downward, that is, the power difference is negatively correlated with the first parameter compensation value. If the power data of the current online battery unit is less than the power average value, the initial charge and discharge power given value needs to be increased, and the greater the difference between the power data of the current online battery unit and the power average value, the greater the amount by which the initial charge and discharge power given value is adjusted upward, that is, the power difference is positively correlated with the first parameter compensation value.

[0054] When the energy storage system is in a discharging state, the charge and discharge power given value is a negative value. If the current online battery unit power data is greater than the power average value, the initial charge and discharge power given value needs to be reduced, and the greater the difference between the current online battery unit power data and the power average value, the greater the amount of downward adjustment of the initial charge and discharge power given value, that is, the power difference is negatively correlated with the first parameter compensation value. If the current online battery unit power data is less than the power average value, the initial charge and discharge power given value needs to be increased, and the greater the difference between the current online battery unit power data and the power average value, the greater the amount of upward adjustment of the initial charge and discharge power given value, that is, the power difference is positively correlated with the first parameter compensation value.

[0055] Specifically, in order to avoid frequent changes in the given value of the charge and discharge power of the battery unit, in this embodiment, when the power difference is within the preset power range, the first parameter compensation value can be set to zero, that is, the initial charge and discharge power given value 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 a possible implementation, another implementation process of S103 includes:

[0057] If the energy storage system is in a charging state, the data of the amount to be charged is obtained according to the power data of the current online battery unit, and the average value of the amount to be charged is obtained according to the average power value;

[0058] Dividing the data of the amount to be charged by the average value of the amount to be charged to obtain a first ratio;

[0059] Multiplying the initial charge and discharge parameter given value by the first ratio to obtain a final charge and discharge parameter given value of the current online battery unit;

[0060] If the energy storage system is in a discharging state, the power data of the current online battery unit is divided by the power average value to obtain a second ratio;

[0061] The initial charge and discharge parameter given value is multiplied by the second ratio to obtain a final charge and discharge parameter given value of the current online battery unit.

[0062] Specifically, the full-scale value of the current online battery unit is subtracted from the power data of the current online battery unit to obtain the data of the amount to be charged. The above method adjusts the given value of the charge and discharge parameters of the corresponding online battery unit based on the ratio of the amount of power that can be charged to the average amount of power to be charged, or the ratio of the amount of power that can be discharged to the average amount of power, so as to achieve power balance of each battery unit during the charging and discharging process of the energy storage system and improve the timeliness of power balance.

[0063] In a possible implementation manner, the charge and discharge parameters include charge and discharge power; and in S103, the charge and discharge control of the current online battery unit is performed based on the final charge and discharge parameter given value, including:

[0064] If the absolute value of the final charging power given value of the currently online battery unit is greater than the charging and discharging power threshold of the currently online battery unit, controlling the output voltage given value of the currently online battery unit to increase;

[0065] If the absolute value of the final discharge power given value of the currently online battery unit is greater than the charge and discharge power threshold of the currently online battery unit, the output voltage given value of the currently online battery unit is controlled to decrease.

[0066] In this embodiment, the charge and discharge power threshold is the maximum charge and discharge power allowed by the online battery unit; each battery unit also needs to stabilize the DC bus voltage while charging and discharging. When the energy storage system is in a charging state, if the absolute value of the final charge power given value of the current online battery unit is greater than the charge and discharge power threshold of the current online battery unit, the output voltage given value of the current online battery unit is controlled to increase. When the energy storage system is in a discharging state, if the absolute value of the final discharge power given value of the current online battery unit is greater than the charge and discharge power threshold of the current online battery unit, the output voltage given value of the current online battery unit is controlled to decrease.

[0067] It can be seen from the above embodiments that the charge and discharge control method of the energy storage system provided in this embodiment can not only achieve power balance between batteries during the charge and discharge 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 order of execution of the steps in the above embodiment does not necessarily mean 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 embodiment of the present invention.

[0069] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0070] Figure 4 The structure diagram of the charge and discharge control device of the energy storage system provided by the embodiment of the present invention is shown. For the convenience of explanation, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

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

[0072] A data acquisition module 110 is used to acquire the power data of all online battery units in the energy storage system and the given values ​​of the initial charge and discharge parameters of the current online battery unit, where the current online battery unit is any online battery unit in the energy storage system;

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

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

[0075] In a possible implementation, the balanced charge and discharge control module 130 includes:

[0076] A parameter adjustment unit, configured to reduce an initial charge and discharge parameter given value of the current online battery unit if the power data of the current online battery unit is greater than the power average value, so as to obtain a final charge and discharge parameter given value of the current online battery unit;

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

[0078] In a possible implementation, the parameter adjustment unit is specifically used to:

[0079] If the power data of the current online battery unit is greater than the power average value, subtract the power average value from the power data of the current online battery unit to obtain a power difference;

[0080] Determine a first parameter compensation value according to the power difference and the working state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the working state includes a charging state and a discharging state;

[0081] The initial charge and discharge parameter given value of the current online battery unit is added to the first parameter compensation value to obtain a final charge and discharge parameter given value of the current online battery unit.

[0082] In a possible implementation, the balanced charge and discharge control module 130 includes:

[0083] If the energy storage system is in a charging state, the data of the amount to be charged is obtained according to the power data of the current online battery unit, and the average value of the amount to be charged is obtained according to the average power value;

[0084] Dividing the data of the amount to be charged by the average value of the amount to be charged to obtain a first ratio;

[0085] Multiplying the initial charge and discharge parameter given value by the first ratio to obtain a final charge and discharge parameter given value of the current online battery unit;

[0086] If the energy storage system is in a discharging state, the power data of the current online battery unit is divided by the power average value to obtain a second ratio;

[0087] The initial charge and discharge parameter given value is multiplied by the second ratio to obtain a final charge and discharge parameter given value of the current online battery unit.

[0088] In a possible implementation, the charge and discharge parameters include the charge and discharge power; and the balanced charge and discharge control module 130 further includes:

[0089] If the absolute value of the final charging power given value of the currently online battery unit is greater than the charging and discharging power threshold of the currently online battery unit, controlling the output voltage given value of the currently online battery unit to increase;

[0090] If the absolute value of the final discharge power given value of the currently online battery unit is greater than the charge and discharge power threshold of the currently online battery unit, the output voltage given value of the currently online battery unit is controlled to decrease.

[0091] In a possible implementation, the charging and discharging parameters include charging and discharging power; and the data acquisition module 110 includes:

[0092] An initial charge and discharge power given value issued by the controller of the energy storage system is obtained; the initial charge and discharge power given value is obtained by dividing the total charge and discharge power given value of the energy storage system by the number of online battery units.

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

[0094] Figure 5 is a schematic diagram of a terminal provided by an embodiment of the present invention. Figure 5As shown, the terminal 5 of this embodiment includes: a processor 50 and a memory 51. The memory 51 is used to store a computer program 52, and the processor 50 is used to call and run the computer program 52 stored in the memory 51 to perform the steps in the above-mentioned various energy storage system charge and discharge control method embodiments, such as Figure 3 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-mentioned device embodiments, for example Figure 4 The functions of the modules 110 to 130 are shown.

[0095] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 52 in the terminal 5. For example, the computer program 52 may 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 appreciate that Figure 5 It is only an example of terminal 5 and does not constitute a limitation on terminal 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and 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 (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) 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, etc.

[0098] The memory 51 may be an internal storage unit of the terminal 5, such as a hard disk or memory of the terminal 5. The memory 51 may also be an external storage device of the terminal 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 5. Further, the memory 51 may also include both an internal storage unit of the terminal 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the terminal. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0099] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by 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 embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0100] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0101] Those skilled in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0102] In the embodiments provided by the present 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 only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0103] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0104] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0105] If the integrated module / unit is implemented in the form of 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, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various energy storage system charge and discharge control method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0106] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A charge and discharge control method for an energy storage system, characterized in that: The energy storage system comprises a plurality of battery cells and a converter module; each battery cell is respectively connected to a corresponding converter module; the method is applied to the converter module; The method comprises: Acquire the power data of all online battery units in the energy storage system and the given values ​​of initial charge and discharge parameters of the current online battery unit, where the current online battery unit is any online battery unit in the energy storage system; Calculate the average power of all online battery units; According to the power data of the current online battery unit and the average power value, the initial charge and discharge parameter given value of the current online battery unit is corrected to obtain the final charge and discharge parameter given value of the current online battery unit, and the charge and discharge of the current online battery unit is controlled based on the final charge and discharge parameter given value.

2. The charge and discharge control method of the energy storage system according to claim 1, characterized in that: According to the power data of the current online battery unit and the power average value, the initial charge and discharge parameter given value of the current online battery unit is corrected to obtain the final charge and discharge parameter given value of the current online battery unit, including: If the power data of the current online battery unit is greater than the power average value, then reducing the initial charge and discharge parameter given value of the current online battery unit to obtain the final charge and discharge parameter given value of the current online battery unit; If the power data of the current online battery unit is less than the power average value, the initial charge and discharge parameter given value of the current online battery unit is increased to obtain the final charge and discharge parameter given value of the current online battery unit.

3. The charge and discharge control method of the energy storage system according to claim 2, characterized in that: If the power data of the current online battery unit is greater than the power average value, reducing the initial charge and discharge parameter given value of the current online battery unit to obtain the final charge and discharge parameter given value of the current online battery unit, including: If the power data of the current online battery unit is greater than the power average value, subtract the power average value from the power data of the current online battery unit to obtain a power difference; Determine a first parameter compensation value according to the power difference and the working state of the energy storage system; the power difference is negatively correlated with the first parameter compensation value; the working state includes a charging state and a discharging state; The initial charge and discharge parameter given value of the current online battery unit is added to the first parameter compensation value to obtain a final charge and discharge parameter given value of the current online battery unit.

4. The charge and discharge control method of the energy storage system according to claim 1, characterized in that: The step of correcting the initial charge and discharge parameter given value of the current online battery unit according to the power data of the current online battery unit and the power average value to obtain the final charge and discharge parameter given value of the current online battery unit includes: If the energy storage system is in a charging state, the data of the amount to be charged is obtained according to the power data of the current online battery unit, and the average value of the amount to be charged is obtained according to the average power value; Dividing the data of the amount to be charged by the average value of the amount to be charged to obtain a first ratio; Multiplying the initial charge and discharge parameter given value by the first ratio to obtain a final charge and discharge parameter given value of the current online battery unit; If the energy storage system is in a discharging state, the power data of the current online battery unit is divided by the power average value to obtain a second ratio; The initial charge and discharge parameter given value is multiplied by the second ratio to obtain a final charge and discharge parameter given value of the current online battery unit.

5. The charge and discharge control method of the energy storage system according to claim 1, characterized in that: The charge and discharge parameters include charge power and discharge power; the charge and discharge control of the current online battery unit based on the final charge and discharge parameter given value includes: If the absolute value of the final charging power given value of the currently online battery unit is greater than the charging and discharging power threshold of the currently online battery unit, controlling the output voltage given value of the currently online battery unit to increase; If the absolute value of the final discharge power given value of the currently online battery unit is greater than the charge and discharge power threshold of the currently online battery unit, the output voltage given value of the currently online battery unit is controlled to decrease.

6. The charge and discharge control method of the energy storage system according to claim 1, characterized in that: The charging and discharging parameters include charging and discharging power; obtaining the initial charging and discharging parameter given value of the current online battery unit includes: An initial charge and discharge power given value issued by the controller of the energy storage system is obtained; the initial charge and discharge power given value is obtained by dividing the total charge and discharge power given value of the energy storage system by the number of online battery units.

7. A controller, characterized in that: It comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the charge and discharge control method of the energy storage system as described in any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for controlling the charge and discharge of the energy storage system as described in any one of claims 1 to 6 are implemented.

9. An energy storage system, characterized in that: It includes an energy storage inverter, multiple battery cells, inverter modules corresponding to each battery cell, and a controller as described in claim 7 corresponding to each inverter module; each battery cell is respectively connected to the first end of the inverter module corresponding to each battery cell, and the second end of each inverter module is connected to the DC end of the energy storage inverter; the AC end of the energy storage inverter is the output end of the energy storage system.

10. An energy storage system, characterized in that: It comprises a plurality of energy storage conversion modules, each of which comprises a battery unit, an energy storage converter and a controller as claimed in claim 7 corresponding to each energy storage converter; Each battery unit is connected to a DC terminal of a 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.

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