Control methods, devices, storage media and products for energy storage systems

Abstract

The present application discloses a control method, device, storage medium and product for an energy storage system. The method includes: obtaining a first working power and a first working voltage of the energy storage system in a first working stage in multiple working stages, wherein the multiple working stages correspond to different working powers, and in each working stage of the multiple working stages, the energy storage system performs the same preset operation, which is a discharge operation or a charging operation; a first working current according to the first working power and the first working voltage; when the first working current is within a first working current interval, controlling the energy storage system to perform a preset operation with the first working current, the first working current interval corresponds to the first voltage sub-interval, the first voltage sub-interval includes the first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system. The solution provided in the present application can improve the stability of the output working power of the energy storage system, thereby improving the safety of the operation of the energy storage system.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a control method, device, storage medium and product of an energy storage system. Background Art

[0002] Energy storage systems are devices that store energy. They can not only store the power of the power grid and provide power for vehicle batteries and equipment, but also transmit the power stored in vehicle batteries or electrical equipment to the power grid to improve the utilization rate of power. How to improve the safety and efficiency of energy storage systems is of great significance. Summary of the invention

[0003] The present application provides a control method, device, storage medium and product of an energy storage system, which can improve the stability of the working power output of the energy storage system, thereby improving the safety of the operation of the energy storage system.

[0004] In a first aspect, the present application provides a control method for an energy storage system, the method comprising: obtaining a first working power and a first working voltage corresponding to the energy storage system in a first working stage, wherein the first working stage is any one of multiple working stages of the energy storage system, the multiple working stages correspond to different working powers, and in each of the multiple working stages, the energy storage system performs the same preset operation, which is a discharge operation or a charging operation; determining a first working current of the energy storage system according to the first working power and the first working voltage; when the first working current is within a first working current interval, controlling the energy storage system to perform a preset operation according to the first working current; wherein the first working current interval corresponds to a first voltage sub-interval, the first voltage sub-interval includes the first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system.

[0005] In the embodiment of the present application, the working current interval corresponding to each voltage sub-interval is set based on the maximum working current of the energy storage system to limit the working current of the energy storage system, so that the working current of the energy storage system is within a reasonable range, reducing the risk of current overload and improving the safety of the energy storage system. In addition, in the embodiment of the present application, the working voltage interval of the energy storage system is divided into multiple voltage sub-intervals, each voltage sub-interval has a corresponding working current interval, and when the energy storage system is charged or discharged, a reasonable working current interval can be determined according to the voltage sub-interval to which the working voltage belongs, so as to improve the stability of the working power output of the energy storage system, thereby improving the safety of the energy storage system.

[0006] It can be seen that the solution provided in the embodiment of the present application can effectively improve the working safety of the energy storage system.

[0007] In some embodiments, after determining the first working current of the energy storage system according to the first working power and the first working voltage, the maximum working current and the working voltage range of the energy storage system are obtained; the working voltage range is divided into multiple voltage sub-ranges; based on the maximum working current, the working current range corresponding to each voltage sub-range is determined; from the multiple voltage sub-ranges, the first voltage sub-range to which the first working voltage belongs is determined; and the working current range corresponding to the first voltage sub-range is determined as the first working current range.

[0008] By establishing an association between the voltage sub-interval and the working current interval, the working current of the energy storage system can be limited by the working current interval during the actual operation of the energy storage system, thereby reducing the risk of current overload during the operation of the energy storage system.

[0009] In some embodiments, the energy storage system includes multiple battery cells, and obtaining the operating voltage range of the energy storage system includes: obtaining the discharge cut-off voltages of the multiple battery cells; calculating the sum of the discharge cut-off voltages of the multiple battery cells to obtain the lower limit of the operating voltage of the energy storage system; determining the upper limit of the operating voltage of the energy storage system based on the maximum operating current and the nominal power of each battery cell in the energy storage system; and determining the operating voltage range based on the lower limit of the operating voltage and the upper limit of the operating voltage.

[0010] The lower limit of the operating voltage of the energy storage system is determined by the discharge cut-off voltage of the battery cell, and the upper limit of the operating voltage of the energy storage system is determined according to the maximum operating current and the nominal capacity of the battery cell. In this way, the operating voltage range for the normal operation of the energy storage system can be determined, and the energy storage system can be controlled to charge or discharge within the operating voltage range, which can improve the stability and safety of the energy storage system.

[0011] In some embodiments, the upper limit value of the operating voltage of the energy storage system is determined based on the maximum operating current and the nominal power of each battery cell in the energy storage system, including: obtaining the number of battery cells included in the energy storage system; determining the upper limit value of the operating power of the energy storage system according to the nominal power of the battery cells and the number of battery cells; determining the upper limit value of the operating voltage according to the upper limit value of the operating power and the maximum operating current.

[0012] By determining the upper limit of the operating voltage of the energy storage system, voltage overload of the energy storage system can be avoided and the safety of the energy storage system operation can be improved.

[0013] In some embodiments, the operating voltage interval is divided into a plurality of voltage sub-intervals, including: obtaining a hysteresis voltage between two adjacent voltage sub-intervals, wherein the hysteresis voltage is a difference between an upper voltage limit value of a previous voltage sub-interval and a lower voltage limit value of a subsequent voltage sub-interval in two adjacent voltage sub-intervals; and dividing the operating voltage interval into a plurality of voltage sub-intervals according to the operating voltage lower limit value, the operating voltage upper limit value, and the hysteresis voltage between two adjacent voltage sub-intervals of the energy storage system.

[0014] In the process of dividing the working voltage interval, the hysteresis voltage is increased to reduce the risk of the maximum power value of the energy storage system repeatedly switching and jumping due to the system voltage of the energy storage system jumping at the boundary of the voltage sub-interval, thereby improving the stability and accuracy of the energy storage system.

[0015] In some embodiments, the working voltage interval is divided into multiple voltage sub-intervals according to the working voltage lower limit value, the working voltage upper limit value, and the hysteresis voltage between two adjacent voltage sub-intervals of the energy storage system, including: calculating the interval voltage between the working voltage intervals based on the working voltage upper limit value and the working voltage lower limit value; calculating the sum of the hysteresis voltages corresponding to multiple voltage sub-intervals to obtain a total hysteresis voltage; subtracting the total hysteresis voltage from the interval voltage to obtain a total working voltage; determining the sub-interval voltage corresponding to each voltage sub-interval according to the total working voltage and the number of multiple voltage sub-intervals; determining the voltage upper limit value and the voltage lower limit value corresponding to each voltage sub-interval based on the working voltage lower limit value, the sub-interval voltage, and the hysteresis voltage corresponding to each voltage sub-interval.

[0016] By dividing the voltage sub-intervals according to the upper and lower limits of the operating voltage of the energy storage system and the hysteresis voltage, the rationality of the voltage sub-interval division is ensured, which provides a basis for the stability of the energy storage system.

[0017] In some embodiments, the working current interval corresponding to each voltage sub-interval is determined based on the maximum working current, including: determining the second working power of the energy storage system according to the voltage lower limit value and the maximum working current of the second voltage sub-interval, wherein the second voltage sub-interval is any one of a plurality of voltage sub-intervals, and the second working power is the maximum working power of the energy storage system when working at a voltage within the second voltage sub-interval; determining the current lower limit value corresponding to the second voltage sub-interval according to the second working power and the upper limit value of the second voltage sub-interval; determining the current upper limit value corresponding to the second voltage sub-interval according to the second working power and the lower limit value of the second voltage sub-interval; and determining the working current interval corresponding to the second voltage sub-interval based on the current upper limit value and the current lower limit value.

[0018] The maximum operating power corresponding to each voltage sub-interval is determined based on the voltage lower limit value of the voltage sub-interval. Therefore, the maximum operating power of each voltage sub-interval is within the operating power range of the energy storage system. Therefore, the current in the operating current interval determined by the maximum operating power is also within the normal operating current range of the energy storage system. Then, the current in the operating current interval is used to realize charging and discharging, which can ensure the safety of the energy storage system.

[0019] In some embodiments, obtaining the maximum operating current of the energy storage system includes: obtaining the maximum withstand current of the components included in the energy storage system; determining a target maximum withstand current with the minimum current from multiple maximum withstand currents; and determining the target maximum withstand current as the maximum operating current.

[0020] The minimum value of the maximum withstand current of the components in the energy storage system is determined as the maximum operating current of the energy storage system, and the maximum operating current is used as a limiting condition for the operation of the energy storage system, thereby ensuring the normal operation of each component in the energy storage system during the operation of the energy storage system and improving the safety and stability of the energy storage system.

[0021] In some embodiments, when the first operating voltage is outside a plurality of voltage sub-intervals, the energy storage system is charged or discharged using the operating current at a previous moment to reduce the frequency with which the system voltage of the energy storage system jumps at the boundary value of the voltage sub-interval, thereby reducing the frequency with which the maximum power usage value of the energy storage system repeatedly switches and jumps, thereby improving the stability of the energy storage system.

[0022] In some embodiments, when the first operating current is outside the first operating current interval, the first operating voltage is adjusted so that the first operating current corresponding to the first operating voltage is within the first operating current interval; and / or, the first operating current is adjusted so that the first operating current is within the first operating current interval.

[0023] By adjusting the first operating voltage and / or the first operating current so that the operating current of the energy storage system is within the operating current range, the risk of current overload is reduced, thereby improving the safety of the operation of the energy storage system.

[0024] In a second aspect, the present application also provides a control device for an energy storage system, the device comprising: a data acquisition module, used to acquire a first working power and a first working voltage corresponding to the energy storage system in a first working stage, wherein the first working stage is any one of multiple working stages of the energy storage system, and the multiple working stages correspond to different working powers, respectively. In each of the multiple working stages, the energy storage system performs the same preset operation, which is a discharge operation or a charging operation; a current determination module, used to determine a first working current of the energy storage system according to the first working power and the first working voltage; a control module, used to control the energy storage system to perform a preset operation according to the first working current when the first working current is within a first working current interval, wherein the first working current interval corresponds to a first voltage sub-interval, the first voltage sub-interval includes the first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system.

[0025] In a third aspect, the present application provides a readable storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the control method of the energy storage system as described in the first aspect is implemented.

[0026] In a fourth aspect, the present application provides a computer program product. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the control method of the energy storage system as described in the first aspect.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0029] Figure 1 This is a schematic diagram of the structure of a charge and discharge control system according to an embodiment of the present application;

[0030] Figure 2 A flow chart of a control method for an energy storage system according to an embodiment of the present application;

[0031] Figure 3 A schematic diagram of a step-by-step charging power change according to an embodiment of the present application;

[0032] Figure 4 A schematic diagram of a change in non-step charging power in the related art;

[0033] Figure 5A flow chart of a method for determining a first operating current interval according to an embodiment of the present application;

[0034] Figure 6 A schematic diagram of a voltage sub-interval division process according to an embodiment of the present application;

[0035] Figure 7 A schematic diagram showing the association between the voltage sub-intervals and the operating current intervals according to an embodiment of the present application;

[0036] Figure 8 A schematic diagram of a control device for an energy storage system according to another embodiment of the present application.

[0037] In the drawings, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] Mentioning "embodiment" in the embodiments of the present application means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiment described in the embodiments of the present application can be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] In the related art, the charge and discharge control of the energy storage system can be realized by the energy storage converter. During the charging and discharging process of the battery in the energy storage system, the battery in the energy storage system can be charged and discharged by constant power charging and discharging and constant power-step-down power charging and discharging.

[0047] However, in the process of controlling charging and discharging by constant power and step-by-step power reduction, the above scheme may cause current overload, which will affect the normal operation of the energy storage system and reduce the safety of the energy storage system. In addition, in the above scheme, the charging and discharging of the energy storage system is realized according to the changes in the load and voltage of the battery. However, in actual applications, the energy storage system cannot control the charging and discharging in real time according to the system status of the energy storage system monitored in real time, and its flexibility is poor. In addition, the above scheme does not take into account the protection of the overall system comprehensively, and cannot be applied to scenarios with high requirements for the stability of the system power output.

[0048] In order to solve the problems existing in the related art, the embodiments of the present application provide a control method, device, storage medium and product for an energy storage system. Among them, the method provided in the embodiments of the present application takes the maximum operating current of the energy storage system as a limiting condition, especially in the scenario where the maximum allowable operating current of the energy storage system is limited due to other components or hardware wiring harness problems, the operating current interval corresponding to each voltage interval is set to achieve a step-by-step limitation of the operating power, so that the operating current of the energy storage system is within a reasonable range, reducing the risk of current overload, and improving the safety of the energy storage system. This solution can be applied to scenarios with high requirements for the safety of the energy storage system and the stability of power output.

[0049] It should be noted that the control method of the energy storage system provided in the embodiment of the present application can be applied to a charge and discharge control system, such as Figure 1 As shown, the charge and discharge control system may include a PCS (Power Conversion System, energy storage converter) and a BMS (Battery Management System, battery management system).

[0050] like Figure 1 As shown in the figure, BMS can obtain the battery status information of the battery in the energy storage system to monitor and evaluate the battery. At the same time, BMS can also send control information to the battery to protect and balance the battery. BMS can send the battery status information to PCS, so that PCS controls the charging or discharging of the energy storage battery according to the battery status information.

[0051] The following Figure 1 The charging and discharging control system shown is the execution body, and the control method of the energy storage system provided in the embodiment of the present application is introduced.

[0052] In one embodiment, Figure 2 A flow chart showing a control method for an energy storage system is shown in FIG. Figure 2 As shown, the method may include the following steps S201 to S203:

[0053] Step S201, obtaining a first working power and a first working voltage corresponding to the energy storage system in a first working stage.

[0054] In step S201, the energy storage system can complete charging or discharging through multiple working stages. In each of the multiple working stages, the energy storage system performs the same preset operation, which includes a discharge operation or a charging operation. That is, in the embodiment of the present application, the multiple working stages can be multiple charging stages or multiple discharging stages, wherein the working power corresponding to the working stage for performing the discharge operation is the discharge power, and the corresponding working voltage is the discharge voltage; similarly, the working power corresponding to the working stage for performing the charging operation is the charging power, and the corresponding working voltage is the charging voltage. The charging duration or discharging duration corresponding to the multiple working stages can be the same or different.

[0055] In the embodiment of the present application, the multiple working stages correspond to different working powers, and the working powers corresponding to the multiple working stages can be increased in sequence according to the working time, thereby realizing step-by-step charging or discharging. Figure 3 In the schematic diagram of the step-by-step charging power change shown, in the charging stage from T1 to T2, the energy storage system is charged with power P1; in the charging stage from T2 to T3, the energy storage system is charged with power P2; in the charging stage from T3 to T4, the energy storage system is charged with power P3, wherein P1<P2<P3.

[0056] It should be noted that for the non-step charging control method, the corresponding charging power change diagram can be as follows: Figure 4 As shown, in Figure 4 In the example, the energy storage system is charged at the same power P1 at all times. In the related art, in order to ensure the stable operation of the energy storage system, for the sake of system safety, the lowest power that each component in the energy storage system can withstand is usually used for charging. For the step-by-step charging scheme, different powers are used for charging at different charging stages, and the charging power increases with the charging stage. Instead of using the lowest power for charging, a higher power is used for charging according to demand. Therefore, Figure 3 In comparison, the step-by-step charging method can improve the charging efficiency of the energy storage system. The discharge scenario of the energy storage system is similar to the charging scenario, so I will not go into details here.

[0057] In step S201, the first working stage is any one of the multiple working stages of the energy storage system. Among them, the BMS monitors the cells of the energy storage batteries contained in the battery cluster in the energy storage system in real time to obtain the working status (for example, charging status, discharging status), remaining power, operating status and other status information of the cells, and analyzes the above status information to determine the charging strategy or discharging strategy for charging or discharging the cells. The charging strategy includes at least the charging power corresponding to each charging stage, and the discharging strategy includes the discharging power corresponding to each discharging stage. The BMS sends the charging strategy or discharging strategy to the PCS, so that the PCS can control the energy storage system to charge or discharge according to the charging strategy or discharging control strategy.

[0058] Step S202: determining a first operating current of the energy storage system according to the first operating power and the first operating voltage.

[0059] In step S202, the BMS in the charge and discharge control system may determine the first operating current of the energy storage system according to the relationship between power, voltage and current. It can be determined by formula (1):

[0060] (1)

[0061] In formula (1), is the first working current; is the first working power; is the first operating voltage.

[0062] Step S203, when the first working current is within the first working current interval, controlling the energy storage system to perform a preset operation according to the first working current.

[0063] In step S203, the first working current interval corresponds to the first voltage sub-interval, and the first working voltage belongs to the first voltage sub-interval. In the embodiment of the present application, the working voltage interval corresponding to the energy storage system is composed of multiple voltage sub-intervals, each voltage sub-interval corresponds to a working current interval, wherein the first working current interval is a working current interval in which the energy storage system can work normally when charging or discharging with a voltage within the first voltage sub-interval; the first working current interval is determined by the maximum working current of the energy storage system, and the first voltage sub-interval is a voltage interval corresponding to the first working voltage.

[0064] In the embodiment of the present application, after the first working current corresponding to the energy storage system is calculated through step S203, the charge and discharge control system determines the first voltage sub-interval to which the first working voltage belongs, and then determines the first working current interval corresponding to the first voltage sub-interval according to the association relationship between the preset voltage sub-interval and the working current interval; further detects whether the first working current is within the first working current interval. If the first working current is within the first working current interval, it indicates that the working current of the energy storage system is within a reasonable interval; if the first working current is outside the first working current interval, it indicates that there is a risk of current overload in the energy storage system, and the working power and / or working voltage of the energy storage system need to be adjusted.

[0065] Based on the scheme defined by the above steps S201 to S203, it can be known that in the embodiment of the present application, the working current interval corresponding to each voltage sub-interval is set based on the maximum working current of the energy storage system to limit the working current of the energy storage system, so that the working current of the energy storage system is within a reasonable range, reducing the risk of current overload and improving the safety of the energy storage system. In addition, in the embodiment of the present application, the working voltage interval of the energy storage system is divided into multiple voltage sub-intervals, each voltage sub-interval has a corresponding working current interval, and when the energy storage system is charged or discharged, a reasonable working current interval can be determined according to the voltage sub-interval to which the working voltage belongs, so as to improve the stability of the working power output of the energy storage system, thereby improving the safety of the energy storage system.

[0066] It can be seen that the solution provided in the embodiment of the present application can effectively improve the working safety of the energy storage system.

[0067] The following is an introduction to the implementation process of the method provided in the embodiment of the present application.

[0068] In one embodiment, the first operating current interval can be Figure 5 The method shown is to determine, Figure 5 As shown, the method may include the following steps S501 to S505:

[0069] Step S501, obtaining the maximum operating current and operating voltage range of the energy storage system;

[0070] Step S502, dividing the operating voltage interval into a plurality of voltage sub-intervals;

[0071] Step S503, determining the operating current interval corresponding to each voltage sub-interval based on the maximum operating current;

[0072] Step S504, determining a first voltage sub-interval to which the first operating voltage belongs from among the multiple voltage sub-intervals;

[0073] Step S505: determine the operating current interval corresponding to the first voltage sub-interval as the first operating current interval.

[0074] Through steps S501 to S505, an association relationship between the voltage sub-interval and the working current interval is established, so that during the actual operation of the energy storage system, the working current of the energy storage system is limited by the working current interval, thereby reducing the risk of current overload during the operation of the energy storage system.

[0075] The following is a detailed introduction to the process of constructing the correlation relationship between the voltage sub-interval and the operating current interval.

[0076] In step S501, the maximum operating current of the energy storage system is determined by the maximum current borne by each component in the energy storage system.

[0077] In one embodiment, the charge and discharge control system first obtains the maximum withstand current of the components included in the energy storage system, determines the target maximum withstand current with the smallest current from multiple maximum withstand currents, and then determines the target maximum withstand current as the maximum operating current. For example, if the maximum withstand current of the battery cell in the energy storage system is A1, the maximum withstand current of the hardware harness is A2, and A1 is greater than A2, then A2 is determined as the maximum operating current corresponding to the energy storage system.

[0078] It should be noted that the minimum value of the maximum withstand current of the components in the energy storage system is determined as the maximum operating current of the energy storage system, and the maximum operating current is used as a limiting condition for the operation of the energy storage system, thereby ensuring the normal operation of each component in the energy storage system during the operation of the energy storage system and improving the safety and stability of the energy storage system.

[0079] In addition, it should be noted that the maximum operating current of the energy storage system can be set as a configuration item, so that the value corresponding to the configuration item can be adjusted according to the energy storage system with different structures to adapt to and be compatible with different project plans and high-voltage wiring harnesses. Moreover, since the configuration item is set, there is no need to update the source code when adjusting the maximum operating current, thereby saving labor costs and time costs and improving the compatibility of the system.

[0080] In addition, in the above step S501, the operating voltage range of the energy storage system is a voltage range in which the energy storage system can work normally, and its corresponding upper and lower voltage limits can be determined according to the historical voltage data of the energy storage system and the nominal power of a single battery cell.

[0081] In one embodiment, the energy storage system includes a plurality of battery cells, wherein the energy storage system includes a plurality of battery clusters, each battery cluster is equipped with a plurality of energy storage batteries, and each energy storage battery includes at least one battery cell. The charge and discharge control system first obtains the discharge cut-off voltages of the plurality of battery cells, and then calculates the sum of the discharge cut-off voltages of the plurality of battery cells to obtain the lower limit of the working voltage of the energy storage system; then determines the upper limit of the working voltage of the energy storage system based on the maximum working current and the nominal power of each battery cell in the energy storage system; finally, determines the working voltage range based on the lower limit of the working voltage and the upper limit of the working voltage.

[0082] In the above embodiment, the operating voltage range of the energy storage system includes an operating voltage lower limit value and an operating voltage upper limit value, that is, when the operating voltage of the energy storage system is within the above operating voltage range, the energy storage system can work normally.

[0083] The lower limit of the working voltage in the working voltage range can be determined by the discharge cut-off voltage of the battery cell. The discharge cut-off voltage of the battery cell is the lowest voltage that can be reached when the battery cell is discharged, that is, when the battery cell voltage drops to the discharge cut-off voltage, the discharge must be stopped to avoid damaging the battery cell. Among them, the discharge cut-off voltage of the battery cell can be determined by the historical voltage data of each battery cell. After obtaining the discharge cut-off voltage of each battery cell, the discharge cut-off voltages of all the batteries included in the energy storage system are summed to obtain the lower limit of the working voltage of the energy storage system.

[0084] The upper limit of the operating voltage in the operating voltage range can be determined by the maximum operating current of the energy storage system and the nominal capacity of the battery cell.

[0085] The lower limit of the operating voltage of the energy storage system is determined by the discharge cut-off voltage of the battery cell, and the upper limit of the operating voltage of the energy storage system is determined according to the maximum operating current and the nominal capacity of the battery cell. In this way, the operating voltage range for the normal operation of the energy storage system can be determined, and the energy storage system can be controlled to charge or discharge within the operating voltage range, which can improve the stability and safety of the energy storage system.

[0086] The upper limit of the working voltage in the working voltage range can be determined based on the maximum working current and the nominal power of each battery cell in the energy storage system. Specifically, the charge and discharge control system first obtains the number of batteries in the energy storage system, and then determines the upper limit of the working power of the energy storage system based on the nominal power of the battery cells and the number of batteries; and then determines the upper limit of the working voltage based on the upper limit of the working power and the maximum working current.

[0087] As an example, the upper limit of the operating power of the energy storage system can be determined by formula (2):

[0088] (2)

[0089] In formula (2), is the upper limit of the working power of the energy storage system; It is the nominal capacity of a single battery cell; is the number of cells.

[0090] The upper limit of the operating voltage of the energy storage system can be determined by formula (3):

[0091] (3)

[0092] In formula (3), is the upper limit of the working voltage of the energy storage system, is the maximum operating current of the energy storage system.

[0093] By determining the upper limit of the operating voltage of the energy storage system, voltage overload of the energy storage system can be avoided and the safety of the energy storage system operation can be improved.

[0094] It should be noted that in order to improve fault tolerance, after calculating the lower limit of the working voltage, the lower limit of the working voltage can be adjusted by rounding down. For example, if the lower limit of the working voltage is 1086V, it will be rounded down to 1080V; for the upper limit of the working voltage, the rounding up method is used to adjust it. For example, if the upper limit of the working voltage is 1223V, it will be rounded up to 1230V.

[0095] Furthermore, after the operating voltage range of the energy storage system is determined, the operating voltage range can be divided into a plurality of voltage sub-ranges to achieve step-by-step power adjustment.

[0096] Specifically, firstly, the hysteresis voltage between two adjacent voltage sub-intervals is obtained, and then, according to the lower limit value of the working voltage of the energy storage system, the upper limit value of the working voltage and the hysteresis voltage between two adjacent voltage sub-intervals, the working voltage interval can be divided into multiple voltage sub-intervals.

[0097] In the above embodiment, the hysteresis voltage is the difference between the voltage upper limit value of the previous voltage sub-interval and the voltage lower limit value of the next voltage sub-interval in two adjacent voltage sub-intervals. For example, the first voltage sub-interval is [1000, 1566] and the second voltage sub-interval is [1571, 2137]. Then, the hysteresis voltage between the first voltage sub-interval and the second voltage sub-interval is 5V.

[0098] It should be noted that the hysteresis voltages between two adjacent voltage sub-intervals may be the same or different. In the embodiment of the present application, the hysteresis voltages between two adjacent voltage sub-intervals are the same as an example for explanation.

[0099] In addition, the interval voltage corresponding to each voltage sub-interval may be the same or different, that is, in the embodiment of the present application, the operating voltage interval may be divided into a plurality of voltage sub-intervals by an equal division method, or the operating voltage interval may be divided into a plurality of voltage sub-intervals by an unequal division method. In the embodiment of the present application, the equal division method is used as an example for explanation.

[0100] In the process of dividing the working voltage interval, a hysteresis voltage is added to reduce the risk of the system voltage of the energy storage system jumping at the boundary of the voltage sub-interval, causing the maximum power value of the energy storage system to repeatedly switch and jump, thereby improving the stability and accuracy of the energy storage system.

[0101] In one embodiment, the charge and discharge control system can be Figure 6 The voltage sub-intervals can be divided in the manner shown in FIG. Figure 6 As shown, the method includes the following steps S601 to S605:

[0102] Step S601, calculating the interval voltage between the working voltage intervals based on the working voltage upper limit value and the working voltage lower limit value;

[0103] Step S602, calculating the sum of hysteresis voltages corresponding to a plurality of voltage sub-intervals to obtain a total hysteresis voltage;

[0104] Step S603, subtracting the total hysteresis voltage from the interval voltage to obtain a total operating voltage;

[0105] Step S604, determining a sub-interval voltage corresponding to each voltage sub-interval according to the total operating voltage and the number of the plurality of voltage sub-intervals;

[0106] Step S605 , determining a voltage upper limit value and a voltage lower limit value corresponding to each voltage sub-interval based on the working voltage lower limit value, the sub-interval voltage, and the hysteresis voltage corresponding to each voltage sub-interval.

[0107] In one example, the working voltage interval is [1000V, 2708V], and the interval voltage corresponding to the working voltage interval is 1708V. The hysteresis voltage corresponding to two adjacent voltage sub-intervals is 5V, and the number of voltage sub-intervals is 3, so the total hysteresis voltage is 10V, the total working voltage is 1698V, and the sub-interval voltage corresponding to each voltage sub-interval is 1698V / 3=566V. The three voltage sub-intervals obtained by division are: [1000V, 1566V], [1571V, 2137V], [2142V, 2708V].

[0108] By dividing the voltage sub-intervals according to the upper and lower limits of the operating voltage of the energy storage system and the hysteresis voltage, the rationality of the voltage sub-interval division is ensured, which provides a basis for the stability of the energy storage system.

[0109] Furthermore, after completing the division of the voltage sub-intervals, the charge and discharge control system determines the working current interval corresponding to each voltage sub-interval based on the maximum working current. Specifically, the charge and discharge control system determines the second working power of the energy storage system according to the voltage lower limit value of the second voltage sub-interval and the maximum working current; then, according to the second working power and the upper limit value of the second voltage sub-interval, the current lower limit value corresponding to the second voltage sub-interval is determined; then, according to the second working power and the lower limit value of the second voltage sub-interval, the current upper limit value corresponding to the second voltage sub-interval is determined; finally, the working current interval corresponding to the second voltage sub-interval is determined based on the current upper limit value and the current lower limit value.

[0110] In the above embodiment, the second voltage sub-interval is any one of the multiple voltage sub-intervals, and the second operating power is the maximum operating power of the energy storage system when operating at a voltage within the second voltage sub-interval. In one example, the second operating power can be determined by formula (4):

[0111] (4)

[0112] In formula (4), is the second operating power in the second voltage sub-interval, is the voltage lower limit value of the second voltage sub-interval, is the maximum operating current.

[0113] It can be seen from the above formula (4) that when calculating the maximum operating power corresponding to each voltage sub-interval, the voltage lower limit value of the voltage sub-interval is used, so that the maximum operating power of each voltage sub-interval is within the operating power range of the energy storage system.

[0114] After determining the maximum operating power corresponding to each voltage sub-interval, the operating current interval corresponding to the voltage sub-interval is determined based on the maximum operating power corresponding to each voltage sub-interval, wherein the current lower limit value and the current upper limit value of the operating current interval can be determined by formula (5) and formula (6) respectively:

[0115] (5)

[0116] (6)

[0117] In formula (5) and formula (6), is the lower limit of the current in the working current range, is the upper limit of the current in the working current range; is the lower limit value of the second voltage sub-interval; is the upper limit value of the second voltage sub-interval.

[0118] It should be noted that the maximum operating power corresponding to each voltage sub-interval is determined based on the voltage lower limit value of the voltage sub-interval. Therefore, the maximum operating power of each voltage sub-interval is within the operating power range of the energy storage system. Therefore, the current in the operating current interval determined by the maximum operating power is also within the normal operating current range of the energy storage system. Then, the current in the operating current interval is used to realize charging and discharging, which can ensure the safety of the energy storage system.

[0119] At this point, the introduction to establishing the association relationship between the voltage sub-interval and the operating current interval is completed.

[0120] In one example, Figure 7 A schematic diagram showing the relationship between the voltage sub-interval and the working current interval is shown, such as Figure 7 As shown, the construction process mainly includes four stages:

[0121] The first stage is mainly used to determine the operating voltage range of the energy storage system, wherein the lower limit of the operating voltage of the operating voltage range of the energy storage system is determined by the historical voltage data of the energy storage system, and the upper limit of the operating voltage of the operating voltage range is determined according to the nominal power of a single battery cell, the number of batteries in the battery cluster and the maximum operating current of the energy storage system.

[0122] The second stage is mainly used to partition the working voltage interval. In the embodiment of the present application, the working voltage interval is divided into multiple voltage sub-intervals according to the working voltage upper limit value and the working voltage lower limit value of the working voltage interval.

[0123] The third stage is mainly used to determine the maximum operating power of each voltage sub-area according to the upper and lower voltage limits corresponding to each voltage sub-interval and the maximum operating current of the energy storage system.

[0124] The fourth stage is mainly used to determine the working current range corresponding to each voltage sub-range according to the maximum working power of each voltage sub-range and the upper and lower voltage limits corresponding to each voltage sub-region.

[0125] Further, after determining the working current interval corresponding to each voltage sub-interval, the charge and discharge control system can apply the working current interval corresponding to the voltage sub-interval to the following example: Figure 1 The control method shown.

[0126] In one embodiment, when the first working voltage is outside of multiple voltage sub-intervals, the energy storage system is charged or discharged with the working current at the last moment. For example, when the first working voltage is detected to be 1570V, which is not in the first voltage sub-interval [1000V, 1566V] and the second voltage sub-interval [1571V, 2137V], the charge and discharge control system controls the energy storage system to charge or discharge the energy storage system with the current value at the last moment, so as to reduce the frequency of the system voltage of the energy storage system jumping at the boundary value of the voltage sub-interval, thereby reducing the frequency of repeated switching and jumping of the maximum power value of the energy storage system, and improving the stability of the energy storage system.

[0127] In one embodiment, when the first operating current is outside the first operating current interval, the first operating voltage is adjusted so that the first operating current corresponding to the first operating voltage is within the first operating current interval; and / or the first operating current is adjusted so that the first operating current is within the first operating current interval.

[0128] By adjusting the first operating voltage and / or the first operating current so that the operating current of the energy storage system is within the operating current range, the risk of current overload is reduced, thereby improving the safety of the operation of the energy storage system.

[0129] In one embodiment, after completing the control of the energy storage system in the first working stage, when the charge and discharge control system detects that the execution time of the preset operation of the energy storage system in the first working stage reaches the preset time, it can be determined that the energy storage system needs to enter the next working stage, that is, the second working stage. Similar to the execution process of the first working stage, in the second working stage, the charge and discharge control system obtains the third working power and the second working voltage corresponding to the energy storage system in the second working stage; then, the second working current of the energy storage system in the second working stage is determined according to the third working power and the second working voltage; when the second working current is in the second working current interval, the charge and discharge control system controls the energy storage system to perform the preset operation according to the second working current.

[0130] In the above embodiment, the second operating current corresponds to the third voltage sub-interval, the second operating voltage belongs to the third voltage sub-interval, and the second operating current interval is determined by the maximum operating current of the energy storage system.

[0131] It should be noted that the way in which the charge and discharge control system controls the energy storage system in the second working stage is similar to the way in which it controls the energy storage system in the first working stage, and examples are not given here one by one.

[0132] This completes the explanation of the method provided in the embodiments of the present application.

[0133] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0134] In one embodiment, Figure 8 A schematic diagram of the control device of the energy storage system is shown. Figure 8 It can be seen that the device 800 includes: a data acquisition module 801 , a current determination module 802 and a control module 803 .

[0135] The data acquisition module 801 is used to acquire a first working power and a first working voltage corresponding to the energy storage system in a first working stage, wherein the first working stage is any one of multiple working stages of the energy storage system, and the multiple working stages correspond to different working powers, respectively. In each of the multiple working stages, the energy storage system performs the same preset operation, which is a discharge operation or a charge operation;

[0136] A current determination module 802, configured to determine a first operating current of the energy storage system according to the first operating power and the first operating voltage;

[0137] The control module 803 is used to control the energy storage system to perform a preset operation according to the first working current when the first working current is within a first working current interval, wherein the first working current interval corresponds to a first voltage sub-interval, the first voltage sub-interval includes a first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system.

[0138] In one embodiment, the control device of the energy storage system further includes: a voltage interval acquisition module, an interval division module, a current association module, an belonging interval determination module, and a current interval determination module. Among them, the voltage interval acquisition module is used to obtain the maximum working current and working voltage interval of the energy storage system after determining the first working current of the energy storage system according to the first working power and the first working voltage; the interval division module is used to divide the working voltage interval into multiple voltage sub-intervals; the current association module is used to determine the working current interval corresponding to each voltage sub-interval based on the maximum working current; the belonging interval determination module is used to determine the first voltage sub-interval to which the first working voltage belongs from multiple voltage sub-intervals; the current interval determination module is used to determine the working current interval corresponding to the first voltage sub-interval as the first working current interval.

[0139] In one embodiment, the energy storage system includes multiple battery cells, and the voltage interval acquisition module includes: a voltage acquisition module, a first voltage calculation module, a second voltage calculation module, and a voltage interval determination module. Among them, the voltage acquisition module is used to obtain the discharge cut-off voltage of multiple battery cells; the first voltage calculation module is used to calculate the sum of the discharge cut-off voltages of multiple battery cells to obtain the lower limit of the working voltage of the energy storage system; the second voltage calculation module is used to determine the upper limit of the working voltage of the energy storage system based on the maximum working current and the nominal power of each battery cell in the energy storage system; the voltage interval determination module is used to determine the working voltage interval based on the lower limit and upper limit of the working voltage.

[0140] In one embodiment, the second voltage calculation module is specifically used to obtain the number of battery cells included in the energy storage system; determine the upper limit of the working power of the energy storage system according to the nominal power of the battery cells and the number of battery cells; and determine the upper limit of the working voltage according to the upper limit of the working power and the maximum working current.

[0141] In one embodiment, the interval division module includes: a hysteresis voltage acquisition module and a first division module. The hysteresis voltage acquisition module is used to obtain the hysteresis voltage between two adjacent voltage sub-intervals, wherein the hysteresis voltage is the difference between the voltage upper limit value of the previous voltage sub-interval and the voltage lower limit value of the next voltage sub-interval in the two adjacent voltage sub-intervals; the first division module is used to divide the working voltage interval into multiple voltage sub-intervals according to the working voltage lower limit value, the working voltage upper limit value and the hysteresis voltage between two adjacent voltage sub-intervals of the energy storage system.

[0142] In one embodiment, the first division module is specifically used to calculate the interval voltage between the working voltage intervals based on the working voltage upper limit value and the working voltage lower limit value; calculate the sum of the hysteresis voltages corresponding to multiple voltage sub-intervals to obtain the total hysteresis voltage; subtract the total hysteresis voltage from the interval voltage to obtain the total working voltage; determine the sub-interval voltage corresponding to each voltage sub-interval based on the total working voltage and the number of multiple voltage sub-intervals; determine the voltage upper limit value and voltage lower limit value corresponding to each voltage sub-interval based on the working voltage lower limit value, the sub-interval voltage and the hysteresis voltage corresponding to each voltage sub-interval.

[0143] In one embodiment, the current association module is specifically used to determine the second operating power of the energy storage system based on the voltage lower limit value and the maximum operating current of the second voltage sub-interval, wherein the second voltage sub-interval is any one of a plurality of voltage sub-intervals, and the second operating power is the maximum operating power of the energy storage system when operating at a voltage within the second voltage sub-interval; determine the current lower limit value corresponding to the second voltage sub-interval based on the second operating power and the upper limit value of the second voltage sub-interval; determine the current upper limit value corresponding to the second voltage sub-interval based on the second operating power and the lower limit value of the second voltage sub-interval; and determine the operating current interval corresponding to the second voltage sub-interval based on the current upper limit value and the current lower limit value.

[0144] In one embodiment, the voltage interval acquisition module is also used to obtain the maximum withstand current of the components included in the energy storage system; determine the target maximum withstand current with the minimum current from multiple maximum withstand currents; and determine the target maximum withstand current as the maximum operating current.

[0145] In one embodiment, the control device of the energy storage system further includes: a first control module, configured to charge or discharge the energy storage system with the working current at a previous moment when the first working voltage is outside the plurality of voltage sub-intervals.

[0146] In one embodiment, the control device of the energy storage system also includes: a second control module, which is used to adjust the first working voltage when the first working current is outside the first working current interval so that the first working current corresponding to the first working voltage is within the first working current interval; and / or adjust the first working current so that the first working current is within the first working current interval.

[0147] In one embodiment, the present application further provides a readable storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the above-mentioned energy storage system control method is implemented.

[0148] In one embodiment, the present application further provides a computer program product. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the above-mentioned method for controlling the energy storage system.

[0149] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0150] The functional blocks shown in the above structural block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memory, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0151] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0152] The above describes various aspects of the present application with reference to the flow chart and / or block diagram of the control method, device, storage medium and product of the energy storage system according to the embodiment of the present application. It should be understood that each box in the flow chart and / or block diagram and the combination of each box in the flow chart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes of the flow chart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flow chart and the combination of boxes in the block diagram and / or flow chart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A control method for an energy storage system, characterized in that: include: Obtaining a first working power and a first working voltage corresponding to a first working stage of the energy storage system, wherein the first working stage is any one of multiple working stages of the energy storage system, the multiple working stages respectively correspond to different working powers, and in each of the multiple working stages, the energy storage system performs the same preset operation, which is a discharging operation or a charging operation; Determining a first operating current of the energy storage system according to the first operating power and the first operating voltage; When the first working current is within a first working current interval, controlling the energy storage system to perform the preset operation according to the first working current; wherein the first working current interval corresponds to a first voltage sub-interval, the first voltage sub-interval includes the first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system; After determining the first working current of the energy storage system according to the first working power and the first working voltage, the method further includes: obtaining the maximum working current and working voltage interval of the energy storage system; dividing the working voltage interval into a plurality of voltage sub-intervals; determining the working current interval corresponding to each voltage sub-interval based on the maximum working current; determining the first voltage sub-interval to which the first working voltage belongs from the plurality of voltage sub-intervals; determining the working current interval corresponding to the first voltage sub-interval as the first working current interval; The operating voltage range of the energy storage system is a voltage range in which the energy storage system can work normally, and the upper limit and lower limit of the operating voltage range are determined according to the historical voltage data of the energy storage system and the nominal power of a single battery cell.

2. The method according to claim 1, characterized in that: The energy storage system includes a plurality of battery cells, and obtaining the operating voltage range of the energy storage system includes: Obtaining discharge cut-off voltages of the multiple battery cells; Calculating the sum of the discharge cut-off voltages of the plurality of battery cells to obtain a lower limit value of the operating voltage of the energy storage system; Determine an upper limit value of the operating voltage of the energy storage system based on the maximum operating current and the nominal capacity of each battery cell in the energy storage system; The operating voltage range is determined based on the operating voltage lower limit value and the operating voltage upper limit value.

3. The method according to claim 2, characterized in that Determining an upper limit value of an operating voltage of the energy storage system based on the maximum operating current and the nominal capacity of each battery cell in the energy storage system includes: Obtaining the number of battery cells included in the energy storage system; Determining an upper limit value of the operating power of the energy storage system according to the nominal power of the battery cell and the number of battery cells; The operating voltage upper limit is determined according to the operating power upper limit and the maximum operating current.

4. The method according to claim 2 or 3, characterized in that: The operating voltage interval is divided into a plurality of voltage sub-intervals, including: Obtaining a hysteresis voltage between two adjacent voltage sub-intervals, wherein the hysteresis voltage is a difference between a voltage upper limit value of a previous voltage sub-interval and a voltage lower limit value of a subsequent voltage sub-interval in the two adjacent voltage sub-intervals; The operating voltage interval is divided into the multiple voltage sub-intervals according to the lower limit value of the operating voltage of the energy storage system, the upper limit value of the operating voltage, and the hysteresis voltage between two adjacent voltage sub-intervals.

5. The method according to claim 4, characterized in that According to the lower limit value of the working voltage of the energy storage system, the upper limit value of the working voltage and the hysteresis voltage between two adjacent voltage sub-intervals, the working voltage interval is divided into the multiple voltage sub-intervals, including: Calculating the interval voltage between the operating voltage intervals based on the operating voltage upper limit value and the operating voltage lower limit value; Calculating the sum of the hysteresis voltages corresponding to the multiple voltage sub-intervals to obtain a total hysteresis voltage; Subtracting the total hysteresis voltage from the interval voltage to obtain a total operating voltage; Determining a sub-interval voltage corresponding to each voltage sub-interval according to the total operating voltage and the number of the multiple voltage sub-intervals; The voltage upper limit value and the voltage lower limit value corresponding to each voltage sub-interval are determined based on the working voltage lower limit value, the sub-interval voltage, and the hysteresis voltage corresponding to each voltage sub-interval.

6. The method according to claim 5, characterized in that Determining the operating current interval corresponding to each voltage sub-interval based on the maximum operating current includes: Determine the second operating power of the energy storage system according to the voltage lower limit value of the second voltage sub-interval and the maximum operating current, wherein the second voltage sub-interval is any one of the multiple voltage sub-intervals, and the second operating power is the maximum operating power of the energy storage system when operating at a voltage within the second voltage sub-interval; Determining a current lower limit value corresponding to the second voltage sub-interval according to the second working power and the upper limit value of the second voltage sub-interval; Determining an upper limit value of a current corresponding to the second voltage sub-interval according to the second working power and a lower limit value of the second voltage sub-interval; An operating current interval corresponding to the second voltage sub-interval is determined based on the current upper limit value and the current lower limit value.

7. The method according to claim 1, characterized in that Obtaining the maximum operating current of the energy storage system, including: Obtaining the maximum withstand current of the components included in the energy storage system; Determining a target maximum withstand current with a minimum current from among a plurality of maximum withstand currents; The target maximum withstand current is determined as the maximum operating current.

8. The method according to claim 1, characterized in that: The method further comprises: When the first operating voltage is outside the multiple voltage sub-intervals, the energy storage system is charged or discharged using the operating current at a previous moment.

9. The method according to claim 1, characterized in that: The method further comprises: When the first operating current is outside the first operating current interval, adjusting the first operating voltage so that the first operating current corresponding to the first operating voltage is within the first operating current interval; and / or, The first operating current is adjusted so that the first operating current is within the first operating current range.

10. A control device for an energy storage system, characterized in that: include: A data acquisition module, used for acquiring a first working power and a first working voltage corresponding to a first working stage of the energy storage system, wherein the first working stage is any one of a plurality of working stages of the energy storage system, the plurality of working stages respectively correspond to different working powers, and in each of the plurality of working stages, the energy storage system performs the same preset operation, which is a discharge operation or a charge operation; a current determination module, configured to determine a first operating current of the energy storage system according to the first operating power and the first operating voltage; a control module, configured to control the energy storage system to perform the preset operation according to the first working current when the first working current is within a first working current interval, wherein the first working current interval corresponds to a first voltage sub-interval, the first voltage sub-interval includes the first working voltage, and the first working current interval is determined by the maximum working current of the energy storage system; a voltage interval acquisition module, used to obtain the maximum working current and working voltage interval of the energy storage system after determining the first working current of the energy storage system according to the first working power and the first working voltage; an interval division module, used to divide the working voltage interval into multiple voltage sub-intervals; a current association module, used to determine the working current interval corresponding to each voltage sub-interval based on the maximum working current; an belonging interval determination module, used to determine the first voltage sub-interval to which the first working voltage belongs from the multiple voltage sub-intervals; a current interval determination module, used to determine the working current interval corresponding to the first voltage sub-interval as the first working current interval; The operating voltage range of the energy storage system is a voltage range in which the energy storage system can work normally, and the upper limit and lower limit of the operating voltage range are determined according to the historical voltage data of the energy storage system and the nominal power of a single battery cell.

11. A readable storage medium, characterized in that: Computer program instructions are stored on the readable storage medium, and when the computer program instructions are executed by the processor, the control method of the energy storage system according to any one of claims 1 to 9 is implemented.

12. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the control method of the energy storage system as described in any one of claims 1 to 9.

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